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Li G, Jang D, Shin Y, Qiang Y, Qi Y, Wang S, Fang H. Cracking modes and force dynamics in the insertion of neural probes into hydrogel brain phantom. J Neural Eng 2024; 21:046009. [PMID: 38885673 PMCID: PMC11225066 DOI: 10.1088/1741-2552/ad5937] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2024] [Revised: 04/23/2024] [Accepted: 06/17/2024] [Indexed: 06/20/2024]
Abstract
Objective. The insertion of penetrating neural probes into the brain is crucial for advancing neuroscience, yet it involves various inherent risks. Prototype probes are typically inserted into hydrogel-based brain phantoms and the mechanical responses are analyzed in order to inform the insertion mechanics duringin vivoimplantation. However, the underlying mechanism of the insertion dynamics of neural probes in hydrogel brain phantoms, particularly the phenomenon of cracking, remains insufficiently understood. This knowledge gap leads to misinterpretations and discrepancies when comparing results obtained from phantom studies to those observed under thein vivoconditions. This study aims to elucidate the impact of probe sharpness and dimensions on the cracking mechanisms and insertion dynamics characterized during the insertion of probes in hydrogel phantoms.Approach. The insertion of dummy probes with different shank shapes defined by the tip angle, width, and thickness is systematically studied. The insertion-induced cracks in the transparent hydrogel were accentuated by an immiscible dye, tracked byin situimaging, and the corresponding insertion force was recorded. Three-dimensional finite element analysis models were developed to obtain the contact stress between the probe tip and the phantom.Main results. The findings reveal a dual pattern: for sharp, slender probes, the insertion forces remain consistently low during the insertion process, owing to continuously propagating straight cracks that align with the insertion direction. In contrast, blunt, thick probes induce large forces that increase rapidly with escalating insertion depth, mainly due to the formation of branched crack with a conical cracking surface, and the subsequent internal compression. This interpretation challenges the traditional understanding that neglects the difference in the cracking modes and regards increased frictional force as the sole factor contributing to higher insertion forces. The critical probe sharpness factors separating straight and branched cracking is identified experimentally, and a preliminary explanation of the transition between the two cracking modes is derived from three-dimensional finite element analysis.Significance. This study presents, for the first time, the mechanism underlying two distinct cracking modes during the insertion of neural probes into hydrogel brain phantoms. The correlations between the cracking modes and the insertion force dynamics, as well as the effects of the probe sharpness were established, offering insights into the design of neural probes via phantom studies and informing future investigations into cracking phenomena in brain tissue during probe implantations.
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Affiliation(s)
- Gen Li
- Thayer School of Engineering, Dartmouth College, Hanover, NH 03755, United States of America
| | - Dongyeol Jang
- Thayer School of Engineering, Dartmouth College, Hanover, NH 03755, United States of America
| | - Yieljae Shin
- Thayer School of Engineering, Dartmouth College, Hanover, NH 03755, United States of America
| | - Yi Qiang
- Thayer School of Engineering, Dartmouth College, Hanover, NH 03755, United States of America
| | - Yongli Qi
- Thayer School of Engineering, Dartmouth College, Hanover, NH 03755, United States of America
| | - Shuodao Wang
- School of Mechanical & Aerospace Engineering, Oklahoma State University, Stillwater, OK 74078, United States of America
| | - Hui Fang
- Thayer School of Engineering, Dartmouth College, Hanover, NH 03755, United States of America
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Lam DV, Javadekar A, Patil N, Yu M, Li L, Menendez DM, Gupta AS, Capadona JR, Shoffstall AJ. Corrigendum to "Platelets and Hemostatic Proteins are Co-Localized with Chronic Neuroinflammation Surrounding Implanted Intracortical Microelectrodes" [Acta Biomaterialia. Volume 166, August 2023, Pages 278-290]. Acta Biomater 2024; 182:303-308. [PMID: 38845260 PMCID: PMC11295673 DOI: 10.1016/j.actbio.2024.05.039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/19/2024]
Affiliation(s)
- Danny V Lam
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH 44106, USA; Advanced Platform Technology Center, Louis Stokes Cleveland VA Medical Center, Cleveland, OH, USA
| | - Anisha Javadekar
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH 44106, USA; Advanced Platform Technology Center, Louis Stokes Cleveland VA Medical Center, Cleveland, OH, USA
| | | | - Marina Yu
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Longshun Li
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH 44106, USA; Advanced Platform Technology Center, Louis Stokes Cleveland VA Medical Center, Cleveland, OH, USA
| | - Dhariyat M Menendez
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH 44106, USA; Advanced Platform Technology Center, Louis Stokes Cleveland VA Medical Center, Cleveland, OH, USA
| | - Anirban Sen Gupta
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Jeffrey R Capadona
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH 44106, USA; Advanced Platform Technology Center, Louis Stokes Cleveland VA Medical Center, Cleveland, OH, USA
| | - Andrew J Shoffstall
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH 44106, USA; Advanced Platform Technology Center, Louis Stokes Cleveland VA Medical Center, Cleveland, OH, USA.
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Li F, Gallego J, Tirko NN, Greaser J, Bashe D, Patel R, Shaker E, Van Valkenburg GE, Alsubhi AS, Wellman S, Singh V, Padilla CG, Gheres KW, Broussard JI, Bagwell R, Mulvihill M, Kozai TDY. Low-intensity pulsed ultrasound stimulation (LIPUS) modulates microglial activation following intracortical microelectrode implantation. Nat Commun 2024; 15:5512. [PMID: 38951525 PMCID: PMC11217463 DOI: 10.1038/s41467-024-49709-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Accepted: 06/13/2024] [Indexed: 07/03/2024] Open
Abstract
Microglia are important players in surveillance and repair of the brain. Implanting an electrode into the cortex activates microglia, produces an inflammatory cascade, triggers the foreign body response, and opens the blood-brain barrier. These changes can impede intracortical brain-computer interfaces performance. Using two-photon imaging of implanted microelectrodes, we test the hypothesis that low-intensity pulsed ultrasound stimulation can reduce microglia-mediated neuroinflammation following the implantation of microelectrodes. In the first week of treatment, we found that low-intensity pulsed ultrasound stimulation increased microglia migration speed by 128%, enhanced microglia expansion area by 109%, and a reduction in microglial activation by 17%, indicating improved tissue healing and surveillance. Microglial coverage of the microelectrode was reduced by 50% and astrocytic scarring by 36% resulting in an increase in recording performance at chronic time. The data indicate that low-intensity pulsed ultrasound stimulation helps reduce the foreign body response around chronic intracortical microelectrodes.
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Affiliation(s)
- Fan Li
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA
- Center for Neural Basis of Cognition, Pittsburgh, PA, USA
- Computational Modeling and Simulation PhD Program, University of Pittsburgh, Pittsburgh, PA, USA
| | - Jazlyn Gallego
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA
- Center for Neural Basis of Cognition, Pittsburgh, PA, USA
| | - Natasha N Tirko
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, PA, USA
| | | | - Derek Bashe
- Washington University in St. Louis, St. Louis, MO, USA
| | - Rudra Patel
- Department of Neuroscience, University of Pittsburgh, Pittsburgh, PA, USA
| | - Eric Shaker
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA
| | | | | | | | - Vanshika Singh
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA
| | - Camila Garcia Padilla
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA
- Center for Neural Basis of Cognition, Pittsburgh, PA, USA
| | | | | | | | | | - Takashi D Y Kozai
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA.
- Center for Neural Basis of Cognition, Pittsburgh, PA, USA.
- Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA, USA.
- McGowan Institute of Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA, USA.
- NeuroTech Center, University of Pittsburgh Brain Institute, Pittsburgh, PA, USA.
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Wellman S, Forrest AM, Douglas MM, Subbaraman A, Zhang G, Kozai TDY. Dynamic changes in structure and function of brain mural cells around chronically implanted microelectrodes. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.11.598494. [PMID: 38915601 PMCID: PMC11195141 DOI: 10.1101/2024.06.11.598494] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/26/2024]
Abstract
Integration of neural interfaces with minimal tissue disruption in the brain is ideal to develop robust tools that can address essential neuroscience questions and combat neurological disorders. However, implantation of intracortical devices provokes severe tissue inflammation within the brain, which requires a high metabolic demand to support a complex series of cellular events mediating tissue degeneration and wound healing. Pericytes, peri-vascular cells involved in blood-brain barrier maintenance, vascular permeability, waste clearance, and angiogenesis, have recently been implicated as potential perpetuators of neurodegeneration in brain injury and disease. While the intimate relationship between pericytes and the cortical microvasculature have been explored in other disease states, their behavior following microelectrode implantation, which is responsible for direct blood vessel disruption and dysfunction, is currently unknown. Using two-photon microscopy we observed dynamic changes in the structure and function of pericytes during implantation of a microelectrode array over a 4-week implantation period. Pericytes respond to electrode insertion through transient increases in intracellular calcium and underlying constriction of capillary vessels. Within days following the initial insertion, we observed an influx of new, proliferating pericytes which contribute to new blood vessel formation. Additionally, we discovered a potentially novel population of reactive immune cells in close proximity to the electrode-tissue interface actively engaging in encapsulation of the microelectrode array. Finally, we determined that intracellular pericyte calcium can be modulated by intracortical microstimulation in an amplitude- and frequency-dependent manner. This study provides a new perspective on the complex biological sequelae occurring the electrode-tissue interface and will foster new avenues of potential research consideration and lead to development of more advanced therapeutic interventions towards improving the biocompatibility of neural electrode technology.
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Nolta NF, Christensen MB, Tresco PA. Advanced age is not a barrier to chronic intracortical single-unit recording in rat cortex. Front Neurosci 2024; 18:1389556. [PMID: 38817909 PMCID: PMC11138162 DOI: 10.3389/fnins.2024.1389556] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2024] [Accepted: 05/02/2024] [Indexed: 06/01/2024] Open
Abstract
Introduction Available evidence suggests that as we age, our brain and immune system undergo changes that increase our susceptibility to injury, inflammation, and neurodegeneration. Since a significant portion of the potential patients treated with a microelectrode-based implant may be older, it is important to understand the recording performance of such devices in an aged population. Methods We studied the chronic recording performance and the foreign body response (FBR) to a clinically used microelectrode array implanted in the cortex of 18-month-old Sprague Dawley rats. Results and discussion To the best of our knowledge, this is the first preclinical study of its type in the older mammalian brain. Here, we show that single-unit recording performance was initially robust then gradually declined over a 12-week period, similar to what has been previously reported using younger adult rats and in clinical trials. In addition, we show that FBR biomarker distribution was similar to what has been previously described for younger adult rats implanted with multi-shank recording arrays in the motor cortex. Using a quantitative immunohistochemcal approach, we observed that the extent of astrogliosis and tissue loss near the recording zone was inversely related to recording performance. A comparison of recording performance with a younger cohort supports the notion that aging, in and of itself, is not a limiting factor for the clinical use of penetrating microelectrode recording arrays for the treatment of certain CNS disorders.
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Affiliation(s)
- Nicholas F. Nolta
- Department of Biomedical Engineering, University of Utah, Salt Lake City, UT, United States
| | - Michael B. Christensen
- Division of Urology, Department of Surgery, University of Utah School of Medicine, Salt Lake City, UT, United States
- Department of Otolaryngology – Head & Neck Surgery, University of Utah School of Medicine, Salt Lake City, UT, United States
| | - Patrick A. Tresco
- Department of Biomedical Engineering, University of Utah, Salt Lake City, UT, United States
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Xiang Y, Zhao Y, Cheng T, Sun S, Wang J, Pei R. Implantable Neural Microelectrodes: How to Reduce Immune Response. ACS Biomater Sci Eng 2024; 10:2762-2783. [PMID: 38591141 DOI: 10.1021/acsbiomaterials.4c00238] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/10/2024]
Abstract
Implantable neural microelectrodes exhibit the great ability to accurately capture the electrophysiological signals from individual neurons with exceptional submillisecond precision, holding tremendous potential for advancing brain science research, as well as offering promising avenues for neurological disease therapy. Although significant advancements have been made in the channel and density of implantable neural microelectrodes, challenges persist in extending the stable recording duration of these microelectrodes. The enduring stability of implanted electrode signals is primarily influenced by the chronic immune response triggered by the slight movement of the electrode within the neural tissue. The intensity of this immune response increases with a higher bending stiffness of the electrode. This Review thoroughly analyzes the sequential reactions evoked by implanted electrodes in the brain and highlights strategies aimed at mitigating chronic immune responses. Minimizing immune response mainly includes designing the microelectrode structure, selecting flexible materials, surface modification, and controlling drug release. The purpose of this paper is to provide valuable references and ideas for reducing the immune response of implantable neural microelectrodes and stimulate their further exploration in the field of brain science.
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Affiliation(s)
- Ying Xiang
- School of Nano-Tech and Nano-Bionics, University of Science and Technology of China (USTC), Hefei 230026, PR China
- CAS Key Laboratory of Nano-Bio Interface, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou 215123, China
| | - Yuewu Zhao
- CAS Key Laboratory of Nano-Bio Interface, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou 215123, China
| | - Tingting Cheng
- CAS Key Laboratory of Nano-Bio Interface, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou 215123, China
| | - Shengkai Sun
- CAS Key Laboratory of Nano-Bio Interface, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou 215123, China
| | - Jine Wang
- Jiangxi Institute of Nanotechnology, Nanchang 330200, China
- College of Medicine and Nursing, Shandong Provincial Engineering Laboratory of Novel Pharmaceutical Excipients, Sustained and Controlled Release Preparations, Dezhou University, Dezhou 253023, China
| | - Renjun Pei
- School of Nano-Tech and Nano-Bionics, University of Science and Technology of China (USTC), Hefei 230026, PR China
- CAS Key Laboratory of Nano-Bio Interface, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou 215123, China
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Suematsu N, Vazquez AL, Kozai TDY. Activation and depression of neural and hemodynamic responses induced by the intracortical microstimulation and visual stimulation in the mouse visual cortex. J Neural Eng 2024; 21:026033. [PMID: 38537268 PMCID: PMC11002944 DOI: 10.1088/1741-2552/ad3853] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2024] [Revised: 02/28/2024] [Accepted: 03/27/2024] [Indexed: 04/09/2024]
Abstract
Objective. Intracortical microstimulation (ICMS) can be an effective method for restoring sensory perception in contemporary brain-machine interfaces. However, the mechanisms underlying better control of neuronal responses remain poorly understood, as well as the relationship between neuronal activity and other concomitant phenomena occurring around the stimulation site.Approach. Different microstimulation frequencies were investigatedin vivoon Thy1-GCaMP6s mice using widefield and two-photon imaging to evaluate the evoked excitatory neural responses across multiple spatial scales as well as the induced hemodynamic responses. Specifically, we quantified stimulation-induced neuronal activation and depression in the mouse visual cortex and measured hemodynamic oxyhemoglobin and deoxyhemoglobin signals using mesoscopic-scale widefield imaging.Main results. Our calcium imaging findings revealed a preference for lower-frequency stimulation in driving stronger neuronal activation. A depressive response following the neural activation preferred a slightly higher frequency stimulation compared to the activation. Hemodynamic signals exhibited a comparable spatial spread to neural calcium signals. Oxyhemoglobin concentration around the stimulation site remained elevated during the post-activation (depression) period. Somatic and neuropil calcium responses measured by two-photon microscopy showed similar dependence on stimulation parameters, although the magnitudes measured in soma was greater than in neuropil. Furthermore, higher-frequency stimulation induced a more pronounced activation in soma compared to neuropil, while depression was predominantly induced in soma irrespective of stimulation frequencies.Significance. These results suggest that the mechanism underlying depression differs from activation, requiring ample oxygen supply, and affecting neurons. Our findings provide a novel understanding of evoked excitatory neuronal activity induced by ICMS and offer insights into neuro-devices that utilize both activation and depression phenomena to achieve desired neural responses.
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Affiliation(s)
- Naofumi Suematsu
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, United States of America
| | - Alberto L Vazquez
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, United States of America
- Center for the Neural Basis of Cognition, University of Pittsburgh and Carnegie Mellon University, Pittsburgh, PA, United States of America
- Department of Radiology, University of Pittsburgh, Pittsburgh, PA, United States of America
- Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA, United States of America
| | - Takashi D Y Kozai
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, United States of America
- Center for the Neural Basis of Cognition, University of Pittsburgh and Carnegie Mellon University, Pittsburgh, PA, United States of America
- Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA, United States of America
- McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA, United States of America
- NeuroTech Center, University of Pittsburgh Brain Institute, Pittsburgh, PA, United States of America
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McNamara IN, Wellman SM, Li L, Eles JR, Savya S, Sohal HS, Angle MR, Kozai TDY. Electrode sharpness and insertion speed reduce tissue damage near high-density penetrating arrays. J Neural Eng 2024; 21:026030. [PMID: 38518365 DOI: 10.1088/1741-2552/ad36e1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Accepted: 03/22/2024] [Indexed: 03/24/2024]
Abstract
Objective. Over the past decade, neural electrodes have played a crucial role in bridging biological tissues with electronic and robotic devices. This study focuses on evaluating the optimal tip profile and insertion speed for effectively implanting Paradromics' high-density fine microwire arrays (FμA) prototypes into the primary visual cortex (V1) of mice and rats, addressing the challenges associated with the 'bed-of-nails' effect and tissue dimpling.Approach. Tissue response was assessed by investigating the impact of electrodes on the blood-brain barrier (BBB) and cellular damage, with a specific emphasis on tailored insertion strategies to minimize tissue disruption during electrode implantation.Main results.Electro-sharpened arrays demonstrated a marked reduction in cellular damage within 50μm of the electrode tip compared to blunt and angled arrays. Histological analysis revealed that slow insertion speeds led to greater BBB compromise than fast and pneumatic methods. Successful single-unit recordings validated the efficacy of the optimized electro-sharpened arrays in capturing neural activity.Significance.These findings underscore the critical role of tailored insertion strategies in minimizing tissue damage during electrode implantation, highlighting the suitability of electro-sharpened arrays for long-term implant applications. This research contributes to a deeper understanding of the complexities associated with high-channel-count microelectrode array implantation, emphasizing the importance of meticulous assessment and optimization of key parameters for effective integration and minimal tissue disruption. By elucidating the interplay between insertion parameters and tissue response, our study lays a strong foundation for the development of advanced implantable devices with a reduction in reactive gliosis and improved performance in neural recording applications.
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Affiliation(s)
- Ingrid N McNamara
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, United States of America
| | - Steven M Wellman
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, United States of America
| | - Lehong Li
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, United States of America
| | - James R Eles
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, United States of America
| | - Sajishnu Savya
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, United States of America
| | | | | | - Takashi D Y Kozai
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, United States of America
- Center of the Basis of Neural Cognition, Pittsburgh, PA, United States of America
- McGowan Institute of Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA, United States of America
- NeuroTech Center, University of Pittsburgh Brain Institute, Pittsburgh, PA, United States of America
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Bhatia A, Hanna J, Stuart T, Kasper KA, Clausen DM, Gutruf P. Wireless Battery-free and Fully Implantable Organ Interfaces. Chem Rev 2024; 124:2205-2280. [PMID: 38382030 DOI: 10.1021/acs.chemrev.3c00425] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2024]
Abstract
Advances in soft materials, miniaturized electronics, sensors, stimulators, radios, and battery-free power supplies are resulting in a new generation of fully implantable organ interfaces that leverage volumetric reduction and soft mechanics by eliminating electrochemical power storage. This device class offers the ability to provide high-fidelity readouts of physiological processes, enables stimulation, and allows control over organs to realize new therapeutic and diagnostic paradigms. Driven by seamless integration with connected infrastructure, these devices enable personalized digital medicine. Key to advances are carefully designed material, electrophysical, electrochemical, and electromagnetic systems that form implantables with mechanical properties closely matched to the target organ to deliver functionality that supports high-fidelity sensors and stimulators. The elimination of electrochemical power supplies enables control over device operation, anywhere from acute, to lifetimes matching the target subject with physical dimensions that supports imperceptible operation. This review provides a comprehensive overview of the basic building blocks of battery-free organ interfaces and related topics such as implantation, delivery, sterilization, and user acceptance. State of the art examples categorized by organ system and an outlook of interconnection and advanced strategies for computation leveraging the consistent power influx to elevate functionality of this device class over current battery-powered strategies is highlighted.
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Affiliation(s)
- Aman Bhatia
- Department of Biomedical Engineering, The University of Arizona, Tucson, Arizona 85721, United States
| | - Jessica Hanna
- Department of Biomedical Engineering, The University of Arizona, Tucson, Arizona 85721, United States
| | - Tucker Stuart
- Department of Biomedical Engineering, The University of Arizona, Tucson, Arizona 85721, United States
| | - Kevin Albert Kasper
- Department of Biomedical Engineering, The University of Arizona, Tucson, Arizona 85721, United States
| | - David Marshall Clausen
- Department of Biomedical Engineering, The University of Arizona, Tucson, Arizona 85721, United States
| | - Philipp Gutruf
- Department of Biomedical Engineering, The University of Arizona, Tucson, Arizona 85721, United States
- Department of Electrical and Computer Engineering, The University of Arizona, Tucson, Arizona 85721, United States
- Bio5 Institute, The University of Arizona, Tucson, Arizona 85721, United States
- Neuroscience Graduate Interdisciplinary Program (GIDP), The University of Arizona, Tucson, Arizona 85721, United States
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Smith TJ, Smith TR, Faruk F, Bendea M, Tirumala Kumara S, Capadona JR, Hernandez-Reynoso AG, Pancrazio JJ. Real-Time Assessment of Rodent Engagement Using ArUco Markers: A Scalable and Accessible Approach for Scoring Behavior in a Nose-Poking Go/No-Go Task. eNeuro 2024; 11:ENEURO.0500-23.2024. [PMID: 38351132 PMCID: PMC11046262 DOI: 10.1523/eneuro.0500-23.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Revised: 01/30/2024] [Accepted: 02/05/2024] [Indexed: 03/07/2024] Open
Abstract
In the field of behavioral neuroscience, the classification and scoring of animal behavior play pivotal roles in the quantification and interpretation of complex behaviors displayed by animals. Traditional methods have relied on video examination by investigators, which is labor-intensive and susceptible to bias. To address these challenges, research efforts have focused on computational methods and image-processing algorithms for automated behavioral classification. Two primary approaches have emerged: marker- and markerless-based tracking systems. In this study, we showcase the utility of "Augmented Reality University of Cordoba" (ArUco) markers as a marker-based tracking approach for assessing rat engagement during a nose-poking go/no-go behavioral task. In addition, we introduce a two-state engagement model based on ArUco marker tracking data that can be analyzed with a rectangular kernel convolution to identify critical transition points between states of engagement and distraction. In this study, we hypothesized that ArUco markers could be utilized to accurately estimate animal engagement in a nose-poking go/no-go behavioral task, enabling the computation of optimal task durations for behavioral testing. Here, we present the performance of our ArUco tracking program, demonstrating a classification accuracy of 98% that was validated against the manual curation of video data. Furthermore, our convolution analysis revealed that, on average, our animals became disengaged with the behavioral task at ∼75 min, providing a quantitative basis for limiting experimental session durations. Overall, our approach offers a scalable, efficient, and accessible solution for automated scoring of rodent engagement during behavioral data collection.
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Affiliation(s)
- Thomas J Smith
- School of Behavioral and Brain Sciences, The University of Texas at Dallas, Richardson, Texas 75080
| | - Trevor R Smith
- Department of Mechanical and Aerospace Engineering, West Virginia University, Morgantown, West Virginia 26506
| | - Fareeha Faruk
- School of Behavioral and Brain Sciences, The University of Texas at Dallas, Richardson, Texas 75080
| | - Mihai Bendea
- School of Behavioral and Brain Sciences, The University of Texas at Dallas, Richardson, Texas 75080
| | - Shreya Tirumala Kumara
- Department of Bioengineering, The University of Texas at Dallas, Richardson, Texas 75080
| | - Jeffrey R Capadona
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio 44106
- Advanced Platform Technology Center, Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland, Ohio 44106
| | | | - Joseph J Pancrazio
- Department of Bioengineering, The University of Texas at Dallas, Richardson, Texas 75080
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11
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Mueller NN, Kim Y, Ocoko MYM, Dernelle P, Kale I, Patwa S, Hermoso AC, Chirra D, Capadona JR, Hess-Dunning A. Effects of Micromachining on Anti-oxidant Elution from a Mechanically-Adaptive Polymer. JOURNAL OF MICROMECHANICS AND MICROENGINEERING : STRUCTURES, DEVICES, AND SYSTEMS 2024; 34:10.1088/1361-6439/ad27f7. [PMID: 38586082 PMCID: PMC10996452 DOI: 10.1088/1361-6439/ad27f7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/09/2024]
Abstract
Intracortical microelectrodes (IMEs) can be used to restore motor and sensory function as a part of brain-computer interfaces in individuals with neuromusculoskeletal disorders. However, the neuroinflammatory response to IMEs can result in their premature failure, leading to reduced therapeutic efficacy. Mechanically-adaptive, resveratrol-eluting (MARE) neural probes target two mechanisms believed to contribute to the neuroinflammatory response by reducing the mechanical mismatch between the brain tissue and device, as well as locally delivering an antioxidant therapeutic. To create the mechanically-adaptive substrate, a dispersion, casting, and evaporation method is used, followed by a microfabrication process to integrate functional recording electrodes on the material. Resveratrol release experiments were completed to generate a resveratrol release profile and demonstrated that the MARE probes are capable of long-term controlled release. Additionally, our results showed that resveratrol can be degraded by laser-micromachining, an important consideration for future device fabrication. Finally, the electrodes were shown to have a suitable impedance for single-unit neural recording and could record single units in vivo.
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Affiliation(s)
- Natalie N Mueller
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, USA
- Advanced Platform Technology Center, Louis Stokes Cleveland VA Medical Center, Cleveland, OH, USA
| | - Youjoung Kim
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, USA
- Advanced Platform Technology Center, Louis Stokes Cleveland VA Medical Center, Cleveland, OH, USA
| | - Mali Ya Mungu Ocoko
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, USA
- Advanced Platform Technology Center, Louis Stokes Cleveland VA Medical Center, Cleveland, OH, USA
| | - Peter Dernelle
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, USA
- Advanced Platform Technology Center, Louis Stokes Cleveland VA Medical Center, Cleveland, OH, USA
| | - Ishani Kale
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, USA
- Advanced Platform Technology Center, Louis Stokes Cleveland VA Medical Center, Cleveland, OH, USA
| | - Simran Patwa
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, USA
- Advanced Platform Technology Center, Louis Stokes Cleveland VA Medical Center, Cleveland, OH, USA
| | - Anna Clarissa Hermoso
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, USA
- Advanced Platform Technology Center, Louis Stokes Cleveland VA Medical Center, Cleveland, OH, USA
| | - Deeksha Chirra
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, USA
- Advanced Platform Technology Center, Louis Stokes Cleveland VA Medical Center, Cleveland, OH, USA
| | - Jeffrey R Capadona
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, USA
- Advanced Platform Technology Center, Louis Stokes Cleveland VA Medical Center, Cleveland, OH, USA
| | - Allison Hess-Dunning
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, USA
- Advanced Platform Technology Center, Louis Stokes Cleveland VA Medical Center, Cleveland, OH, USA
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12
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Duncan JL, Wang JJ, Glusauskas G, Weagraff GR, Gao Y, Hoeferlin GF, Hunter AH, Hess-Dunning A, Ereifej ES, Capadona JR. In Vivo Characterization of Intracortical Probes with Focused Ion Beam-Etched Nanopatterned Topographies. MICROMACHINES 2024; 15:286. [PMID: 38399014 PMCID: PMC10893395 DOI: 10.3390/mi15020286] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2024] [Revised: 02/09/2024] [Accepted: 02/14/2024] [Indexed: 02/25/2024]
Abstract
(1) Background: Intracortical microelectrodes (IMEs) are an important part of interfacing with the central nervous system (CNS) and recording neural signals. However, recording electrodes have shown a characteristic steady decline in recording performance owing to chronic neuroinflammation. The topography of implanted devices has been explored to mimic the nanoscale three-dimensional architecture of the extracellular matrix. Our previous work used histology to study the implant sites of non-recording probes and showed that a nanoscale topography at the probe surface mitigated the neuroinflammatory response compared to probes with smooth surfaces. Here, we hypothesized that the improvement in the neuroinflammatory response for probes with nanoscale surface topography would extend to improved recording performance. (2) Methods: A novel design modification was implemented on planar silicon-based neural probes by etching nanopatterned grooves (with a 500 nm pitch) into the probe shank. To assess the hypothesis, two groups of rats were implanted with either nanopatterned (n = 6) or smooth control (n = 6) probes, and their recording performance was evaluated over 4 weeks. Postmortem gene expression analysis was performed to compare the neuroinflammatory response from the two groups. (3) Results: Nanopatterned probes demonstrated an increased impedance and noise floor compared to controls. However, the recording performances of the nanopatterned and smooth probes were similar, with active electrode yields for control probes and nanopatterned probes being approximately 50% and 45%, respectively, by 4 weeks post-implantation. Gene expression analysis showed one gene, Sirt1, differentially expressed out of 152 in the panel. (4) Conclusions: this study provides a foundation for investigating novel nanoscale topographies on neural probes.
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Affiliation(s)
- Jonathan L. Duncan
- Department of Biomedical Engineering, Case Western Reserve University, 10900 Euclid Ave, Cleveland, OH 44106, USA
- Advanced Platform Technology Center, Louis Stokes Cleveland Veterans Affairs Medical Center, 10701 East Blvd, Cleveland, OH 44106, USA
| | - Jaime J. Wang
- Department of Biomedical Engineering, Case Western Reserve University, 10900 Euclid Ave, Cleveland, OH 44106, USA
- Advanced Platform Technology Center, Louis Stokes Cleveland Veterans Affairs Medical Center, 10701 East Blvd, Cleveland, OH 44106, USA
| | - Gabriele Glusauskas
- Department of Biomedical Engineering, Case Western Reserve University, 10900 Euclid Ave, Cleveland, OH 44106, USA
- Advanced Platform Technology Center, Louis Stokes Cleveland Veterans Affairs Medical Center, 10701 East Blvd, Cleveland, OH 44106, USA
| | - Gwendolyn R. Weagraff
- Advanced Platform Technology Center, Louis Stokes Cleveland Veterans Affairs Medical Center, 10701 East Blvd, Cleveland, OH 44106, USA
| | - Yue Gao
- Department of Biomedical Engineering, Case Western Reserve University, 10900 Euclid Ave, Cleveland, OH 44106, USA
| | - George F. Hoeferlin
- Department of Biomedical Engineering, Case Western Reserve University, 10900 Euclid Ave, Cleveland, OH 44106, USA
- Advanced Platform Technology Center, Louis Stokes Cleveland Veterans Affairs Medical Center, 10701 East Blvd, Cleveland, OH 44106, USA
| | - Allen H. Hunter
- Michigan Center for Materials Characterization, University of Michigan, 500 S. State St, Ann Arbor, MI 48109, USA
| | - Allison Hess-Dunning
- Department of Biomedical Engineering, Case Western Reserve University, 10900 Euclid Ave, Cleveland, OH 44106, USA
- Advanced Platform Technology Center, Louis Stokes Cleveland Veterans Affairs Medical Center, 10701 East Blvd, Cleveland, OH 44106, USA
| | - Evon S. Ereifej
- Department of Biomedical Engineering, University of Michigan, 500 S. State St, Ann Arbor, MI 48109, USA
- Veterans Affairs Hospital, 2215 Fuller Rd, Ann Arbor, MI 48105, USA
| | - Jeffrey R. Capadona
- Department of Biomedical Engineering, Case Western Reserve University, 10900 Euclid Ave, Cleveland, OH 44106, USA
- Advanced Platform Technology Center, Louis Stokes Cleveland Veterans Affairs Medical Center, 10701 East Blvd, Cleveland, OH 44106, USA
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13
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Suematsu N, Vazquez AL, Kozai TD. Activation and depression of neural and hemodynamic responses induced by the intracortical microstimulation and visual stimulation in the mouse visual cortex. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.01.573814. [PMID: 38260671 PMCID: PMC10802282 DOI: 10.1101/2024.01.01.573814] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2024]
Abstract
Objective . Intracortical microstimulation can be an effective method for restoring sensory perception in contemporary brain-machine interfaces. However, the mechanisms underlying better control of neuronal responses remain poorly understood, as well as the relationship between neuronal activity and other concomitant phenomena occurring around the stimulation site. Approach . Different microstimulation frequencies were investigated in vivo on Thy1-GCaMP6s mice using widefield and two-photon imaging to evaluate the evoked excitatory neural responses across multiple spatial scales as well as the induced hemodynamic responses. Specifically, we quantified stimulation-induced neuronal activation and depression in the mouse visual cortex and measured hemodynamic oxyhemoglobin and deoxyhemoglobin signals using mesoscopic-scale widefield imaging. Main results . Our calcium imaging findings revealed a preference for lower-frequency stimulation in driving stronger neuronal activation. A depressive response following the neural activation preferred a slightly higher frequency stimulation compared to the activation. Hemodynamic signals exhibited a comparable spatial spread to neural calcium signals. Oxyhemoglobin concentration around the stimulation site remained elevated during the post-activation (depression) period. Somatic and neuropil calcium responses measured by two-photon microscopy showed similar dependence on stimulation parameters, although the magnitudes measured in soma was greater than in neuropil. Furthermore, higher-frequency stimulation induced a more pronounced activation in soma compared to neuropil, while depression was predominantly induced in soma irrespective of stimulation frequencies. Significance . These results suggest that the mechanism underlying depression differs from activation, requiring ample oxygen supply, and affecting neurons. Our findings provide a novel understanding of evoked excitatory neuronal activity induced by intracortical microstimulation and offer insights into neuro-devices that utilize both activation and depression phenomena to achieve desired neural responses.
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Li F, Gallego J, Tirko NN, Greaser J, Bashe D, Patel R, Shaker E, Van Valkenburg GE, Alsubhi AS, Wellman S, Singh V, Padill CG, Gheres KW, Bagwell R, Mulvihill M, Kozai TDY. Low-intensity pulsed ultrasound stimulation (LIPUS) modulates microglial activation following intracortical microelectrode implantation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.05.570162. [PMID: 38105969 PMCID: PMC10723293 DOI: 10.1101/2023.12.05.570162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2023]
Abstract
Microglia are important players in surveillance and repair of the brain. Their activation mediates neuroinflammation caused by intracortical microelectrode implantation, which impedes the application of intracortical brain-computer interfaces (BCIs). While low-intensity pulsed ultrasound stimulation (LIPUS) can attenuate microglial activation, its potential to modulate the microglia-mediated neuroinflammation and enhance the bio-integration of microelectrodes remains insufficiently explored. We found that LIPUS increased microglia migration speed from 0.59±0.04 to 1.35±0.07 µm/hr on day 1 and enhanced microglia expansion area from 44.50±6.86 to 93.15±8.77 µm 2 /min on day 7, indicating improved tissue healing and surveillance. Furthermore, LIPUS reduced microglial activation by 17% on day 6, vessel-associated microglia ratio from 70.67±6.15 to 40.43±3.87% on day 7, and vessel diameter by 20% on day 28. Additionally, microglial coverage of the microelectrode was reduced by 50% in week 1, indicating better tissue-microelectrode integration. These data reveal that LIPUS helps resolve neuroinflammation around chronic intracortical microelectrodes.
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15
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Hernandez-Reynoso AG, Sturgill BS, Hoeferlin GF, Druschel LN, Krebs OK, Menendez DM, Thai TTD, Smith TJ, Duncan J, Zhang J, Mittal G, Radhakrishna R, Desai MS, Cogan SF, Pancrazio JJ, Capadona JR. The effect of a Mn(III)tetrakis(4-benzoic acid)porphyrin (MnTBAP) coating on the chronic recording performance of planar silicon intracortical microelectrode arrays. Biomaterials 2023; 303:122351. [PMID: 37931456 PMCID: PMC10842897 DOI: 10.1016/j.biomaterials.2023.122351] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Revised: 09/27/2023] [Accepted: 10/11/2023] [Indexed: 11/08/2023]
Abstract
Intracortical microelectrode arrays (MEAs) are used to record neural activity. However, their implantation initiates a neuroinflammatory cascade, involving the accumulation of reactive oxygen species, leading to interface failure. Here, we coated commercially-available MEAs with Mn(III)tetrakis(4-benzoic acid)porphyrin (MnTBAP), to mitigate oxidative stress. First, we assessed the in vitro cytotoxicity of modified sample substrates. Then, we implanted 36 rats with uncoated, MnTBAP-coated ("Coated"), or (3-Aminopropyl)triethoxysilane (APTES)-coated devices - an intermediate step in the coating process. We assessed electrode performance during the acute (1-5 weeks), sub-chronic (6-11 weeks), and chronic (12-16 weeks) phases after implantation. Three subsets of animals were euthanized at different time points to assess the acute, sub-chronic and chronic immunohistological responses. Results showed that MnTBAP coatings were not cytotoxic in vitro, and their implantation in vivo improved the proportion of electrodes during the sub-chronic and chronic phases; APTES coatings resulted in failure of the neural interface during the chronic phase. In addition, MnTBAP coatings improved the quality of the signal throughout the study and reduced the neuroinflammatory response around the implant as early as two weeks, an effect that remained consistent for months post-implantation. Together, these results suggest that MnTBAP coatings are a potentially useful modification to improve MEA reliability.
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Affiliation(s)
- Ana G Hernandez-Reynoso
- Department of Bioengineering, The University of Texas at Dallas, 800 W Campbell Rd, Richardson, TX, 75080, United States.
| | - Brandon S Sturgill
- Department of Bioengineering, The University of Texas at Dallas, 800 W Campbell Rd, Richardson, TX, 75080, United States.
| | - George F Hoeferlin
- Department of Biomedical Engineering, Case Western Reserve University, 10900 Euclid Ave, Cleveland, OH, 44106, United States; Advanced Platform Technology Center, Louis Stokes Cleveland Veterans Affairs Medical Center, 10701 East Blvd, Cleveland, OH, 44106, United States.
| | - Lindsey N Druschel
- Department of Biomedical Engineering, Case Western Reserve University, 10900 Euclid Ave, Cleveland, OH, 44106, United States; Advanced Platform Technology Center, Louis Stokes Cleveland Veterans Affairs Medical Center, 10701 East Blvd, Cleveland, OH, 44106, United States.
| | - Olivia K Krebs
- Department of Biomedical Engineering, Case Western Reserve University, 10900 Euclid Ave, Cleveland, OH, 44106, United States; Advanced Platform Technology Center, Louis Stokes Cleveland Veterans Affairs Medical Center, 10701 East Blvd, Cleveland, OH, 44106, United States.
| | - Dhariyat M Menendez
- Department of Biomedical Engineering, Case Western Reserve University, 10900 Euclid Ave, Cleveland, OH, 44106, United States; Advanced Platform Technology Center, Louis Stokes Cleveland Veterans Affairs Medical Center, 10701 East Blvd, Cleveland, OH, 44106, United States.
| | - Teresa T D Thai
- Department of Bioengineering, The University of Texas at Dallas, 800 W Campbell Rd, Richardson, TX, 75080, United States.
| | - Thomas J Smith
- School of Behavioral and Brain Sciences, The University of Texas at Dallas, 800 W Campbell Rd, Richardson, TX, 75080, United States.
| | - Jonathan Duncan
- Department of Biomedical Engineering, Case Western Reserve University, 10900 Euclid Ave, Cleveland, OH, 44106, United States; Advanced Platform Technology Center, Louis Stokes Cleveland Veterans Affairs Medical Center, 10701 East Blvd, Cleveland, OH, 44106, United States.
| | - Jichu Zhang
- Department of Biomedical Engineering, Case Western Reserve University, 10900 Euclid Ave, Cleveland, OH, 44106, United States; Advanced Platform Technology Center, Louis Stokes Cleveland Veterans Affairs Medical Center, 10701 East Blvd, Cleveland, OH, 44106, United States.
| | - Gaurav Mittal
- Department of Biomedical Engineering, Case Western Reserve University, 10900 Euclid Ave, Cleveland, OH, 44106, United States; Advanced Platform Technology Center, Louis Stokes Cleveland Veterans Affairs Medical Center, 10701 East Blvd, Cleveland, OH, 44106, United States.
| | - Rahul Radhakrishna
- Department of Bioengineering, The University of Texas at Dallas, 800 W Campbell Rd, Richardson, TX, 75080, United States.
| | - Mrudang Spandan Desai
- Department of Bioengineering, The University of Texas at Dallas, 800 W Campbell Rd, Richardson, TX, 75080, United States.
| | - Stuart F Cogan
- Department of Bioengineering, The University of Texas at Dallas, 800 W Campbell Rd, Richardson, TX, 75080, United States.
| | - Joseph J Pancrazio
- Department of Bioengineering, The University of Texas at Dallas, 800 W Campbell Rd, Richardson, TX, 75080, United States.
| | - Jeffrey R Capadona
- Department of Biomedical Engineering, Case Western Reserve University, 10900 Euclid Ave, Cleveland, OH, 44106, United States; Advanced Platform Technology Center, Louis Stokes Cleveland Veterans Affairs Medical Center, 10701 East Blvd, Cleveland, OH, 44106, United States.
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16
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Sanda R, Yamashita K, Sawahata H, Sakamoto K, Yamagiwa S, Yokoyama S, Numano R, Koida K, Kawano T. Low-invasive neural recording in mouse models with diabetes via an ultrasmall needle-electrode. Biosens Bioelectron 2023; 240:115605. [PMID: 37669586 DOI: 10.1016/j.bios.2023.115605] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Revised: 08/11/2023] [Accepted: 08/14/2023] [Indexed: 09/07/2023]
Abstract
Diabetes is known to cause a variety of complications, having a high correlation with Alzheimer's disease. Electrophysiological recording using a microscale needle electrode is a promising technology for the study, however, diabetic brain tissue is more difficult to record neuronal activities than normal tissue due to these complications including the development of cerebrovascular disease. Here we show an electrophysiological methodology for diabetic db/db mice (+Leprdb/+Leprdb) using a 4-μm-tip diameter needle-electrode device. The needle electrode minimized the tissue injury when compared to a typical larger metal electrode, as confirmed by bleeding during penetration. The proposed electrode device showed both acute and chronic in vivo recording capabilities for diabetic mice while reducing the glial cells' responses. Because of these device characteristics, the 4-μm-tip diameter needle-electrode will allow electrophysiological studies on diabetes models of not only mice, as proven in this study, but also other animals.
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Affiliation(s)
- Rioki Sanda
- Department of Electrical and Electronic Information Engineering, Toyohashi University of Technology, 1-1 Hibarigaoka Tempaku-cho, Toyohashi, 441-8580, Japan
| | - Koji Yamashita
- Electronics-Interdisciplinary Research Institute (EIIRIS), Toyohashi University of Technology, 1-1 Hibarigaoka Tempaku-cho, Toyohashi, 441-8580, Japan
| | - Hirohito Sawahata
- National Institute of Technology, Ibaraki College, 866 Nakane, Hitachinaka, 312-8508, Japan
| | - Kensei Sakamoto
- Department of Electrical and Electronic Information Engineering, Toyohashi University of Technology, 1-1 Hibarigaoka Tempaku-cho, Toyohashi, 441-8580, Japan
| | - Shota Yamagiwa
- Department of Electrical and Electronic Information Engineering, Toyohashi University of Technology, 1-1 Hibarigaoka Tempaku-cho, Toyohashi, 441-8580, Japan
| | - Shohei Yokoyama
- TechnoPro, Inc., TechnoPro R&D Company, 6-10-1 Roppongi, Minato-ku, 106-6135, Japan
| | - Rika Numano
- Electronics-Interdisciplinary Research Institute (EIIRIS), Toyohashi University of Technology, 1-1 Hibarigaoka Tempaku-cho, Toyohashi, 441-8580, Japan; Department of Applied Chemistry and Life Science, Toyohashi University of Technology, 1-1 Hibarigaoka Tempaku-cho, Toyohashi, 441-8580, Japan
| | - Kowa Koida
- Electronics-Interdisciplinary Research Institute (EIIRIS), Toyohashi University of Technology, 1-1 Hibarigaoka Tempaku-cho, Toyohashi, 441-8580, Japan; Department of Computer Science and Engineering, Toyohashi University of Technology, 1-1 Hibarigaoka Tempaku-cho, Toyohashi, 441-8580, Japan
| | - Takeshi Kawano
- Department of Electrical and Electronic Information Engineering, Toyohashi University of Technology, 1-1 Hibarigaoka Tempaku-cho, Toyohashi, 441-8580, Japan; Electronics-Interdisciplinary Research Institute (EIIRIS), Toyohashi University of Technology, 1-1 Hibarigaoka Tempaku-cho, Toyohashi, 441-8580, Japan.
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17
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Chen K, Forrest A, Gonzalez Burgos G, Kozai TDY. Neuronal functional connectivity is impaired in a layer dependent manner near the chronically implanted microelectrodes. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.06.565852. [PMID: 37986883 PMCID: PMC10659303 DOI: 10.1101/2023.11.06.565852] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2023]
Abstract
Objective This study aims to reveal longitudinal changes in functional network connectivity within and across different brain structures near the chronically implanted microelectrode. While it is well established that the foreign-body response (FBR) contributes to the gradual decline of the signals recorded from brain implants over time, how does the FBR impact affect the functional stability of neural circuits near implanted Brain-Computer Interfaces (BCIs) remains unknown. This research aims to illuminate how the chronic FBR can alter local neural circuit function and the implications for BCI decoders. Approach This study utilized multisite Michigan-style microelectrodes that span all cortical layers and the hippocampal CA1 region to collect spontaneous and visually-evoked electrophysiological activity. Alterations in neuronal activity near the microelectrode were tested assessing cross-frequency synchronization of LFP and spike entrainment to LFP oscillatory activity throughout 16 weeks after microelectrode implantation. Main Results The study found that cortical layer 4, the input-receiving layer, maintained activity over the implantation time. However, layers 2/3 rapidly experienced severe impairment, leading to a loss of proper intralaminar connectivity in the downstream output layers 5/6. Furthermore, the impairment of interlaminar connectivity near the microelectrode was unidirectional, showing decreased connectivity from Layers 2/3 to Layers 5/6 but not the reverse direction. In the hippocampus, CA1 neurons gradually became unable to properly entrain to the surrounding LFP oscillations. Significance This study provides a detailed characterization of network connectivity dysfunction over long-term microelectrode implantation periods. This new knowledge could contribute to the development of targeted therapeutic strategies aimed at improving the health of the tissue surrounding brain implants and potentially inform engineering of adaptive decoders as the FBR progresses. Our study's understanding of the dynamic changes in the functional network over time opens the door to developing interventions for improving the long-term stability and performance of intracortical microelectrodes.
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18
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Zhang Y, Wu X, Vadlamani RA, Lim Y, Kim J, David K, Gilbert E, Li Y, Wang R, Jiang S, Wang A, Sontheimer H, English DF, Emori S, Davalos RV, Poelzing S, Jia X. Submillimeter Multifunctional Ferromagnetic Fiber Robots for Navigation, Sensing, and Modulation. Adv Healthc Mater 2023; 12:e2300964. [PMID: 37473719 PMCID: PMC10799194 DOI: 10.1002/adhm.202300964] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Revised: 06/21/2023] [Accepted: 06/26/2023] [Indexed: 07/22/2023]
Abstract
Small-scale robots capable of remote active steering and navigation offer great potential for biomedical applications. However, the current design and manufacturing procedure impede their miniaturization and integration of various diagnostic and therapeutic functionalities. Herein, submillimeter fiber robots that can integrate navigation, sensing, and modulation functions are presented. These fiber robots are fabricated through a scalable thermal drawing process at a speed of 4 meters per minute, which enables the integration of ferromagnetic, electrical, optical, and microfluidic composite with an overall diameter of as small as 250 µm and a length of as long as 150 m. The fiber tip deflection angle can reach up to 54o under a uniform magnetic field of 45 mT. These fiber robots can navigate through complex and constrained environments, such as artificial vessels and brain phantoms. Moreover, Langendorff mouse hearts model, glioblastoma micro platforms, and in vivo mouse models are utilized to demonstrate the capabilities of sensing electrophysiology signals and performing a localized treatment. Additionally, it is demonstrated that the fiber robots can serve as endoscopes with embedded waveguides. These fiber robots provide a versatile platform for targeted multimodal detection and treatment at hard-to-reach locations in a minimally invasive and remotely controllable manner.
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Affiliation(s)
- Yujing Zhang
- Bradley Department of Electrical and Computer Engineering, Virginia Tech, Blacksburg, VA, 24061, USA
| | - Xiaobo Wu
- Translational Biology, Medicine, and Health Graduate Program, Virginia Tech, Roanoke, VA, 24016, USA
- Center for Heart and Reparative Medicine Research, Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, VA, 24016, USA
| | - Ram Anand Vadlamani
- Department of Biomedical Engineering and Mechanics, Virginia Tech, Blacksburg, VA, 24061, USA
| | - Youngmin Lim
- Department of Physics, Virginia Tech, Blacksburg, VA, 24061, USA
| | - Jongwoon Kim
- Bradley Department of Electrical and Computer Engineering, Virginia Tech, Blacksburg, VA, 24061, USA
| | - Kailee David
- Department of Biomedical Engineering and Mechanics, Virginia Tech, Blacksburg, VA, 24061, USA
| | - Earl Gilbert
- Department of Biomedical Engineering and Mechanics, Virginia Tech, Blacksburg, VA, 24061, USA
- School of Neuroscience, Virginia Tech, Blacksburg, VA, 24061, USA
| | - You Li
- Bradley Department of Electrical and Computer Engineering, Virginia Tech, Blacksburg, VA, 24061, USA
| | - Ruixuan Wang
- Bradley Department of Electrical and Computer Engineering, Virginia Tech, Blacksburg, VA, 24061, USA
| | - Shan Jiang
- Bradley Department of Electrical and Computer Engineering, Virginia Tech, Blacksburg, VA, 24061, USA
| | - Anbo Wang
- Bradley Department of Electrical and Computer Engineering, Virginia Tech, Blacksburg, VA, 24061, USA
| | - Harald Sontheimer
- Department of Neuroscience, University of Virginia, Charlottesville, VA, 22903, USA
| | | | - Satoru Emori
- Department of Physics, Virginia Tech, Blacksburg, VA, 24061, USA
| | - Rafael V Davalos
- Department of Biomedical Engineering and Mechanics, Virginia Tech, Blacksburg, VA, 24061, USA
| | - Steven Poelzing
- Translational Biology, Medicine, and Health Graduate Program, Virginia Tech, Roanoke, VA, 24016, USA
- Center for Heart and Reparative Medicine Research, Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, VA, 24016, USA
| | - Xiaoting Jia
- Bradley Department of Electrical and Computer Engineering, Virginia Tech, Blacksburg, VA, 24061, USA
- School of Neuroscience, Virginia Tech, Blacksburg, VA, 24061, USA
- Department of Materials Science and Engineering, Virginia Tech, Blacksburg, VA, 24061, USA
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19
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Chen K, Garcia Padilla C, Kiselyov K, Kozai TDY. Cell-specific alterations in autophagy-lysosomal activity near the chronically implanted microelectrodes. Biomaterials 2023; 302:122316. [PMID: 37738741 PMCID: PMC10897938 DOI: 10.1016/j.biomaterials.2023.122316] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2023] [Revised: 08/22/2023] [Accepted: 09/02/2023] [Indexed: 09/24/2023]
Abstract
Intracortical microelectrodes that can record and stimulate brain activity have become a valuable technique for basic science research and clinical applications. However, long-term implantation of these microelectrodes can lead to progressive neurodegeneration in the surrounding microenvironment, characterized by elevation in disease-associated markers. Dysregulation of autophagy-lysosomal degradation, a major intracellular waste removal process, is considered a key factor in the onset and progression of neurodegenerative diseases. It is plausible that similar dysfunctions in autophagy-lysosomal degradation contribute to tissue degeneration following implantation-induced focal brain injury, ultimately impacting recording performance. To understand how the focal, persistent brain injury caused by long-term microelectrode implantation impairs autophagy-lysosomal pathway, we employed two-photon microscopy and immunohistology. This investigation focused on the spatiotemporal characterization of autophagy-lysosomal activity near the chronically implanted microelectrode. We observed an aberrant accumulation of immature autophagy vesicles near the microelectrode over the chronic implantation period. Additionally, we found deficits in autophagy-lysosomal clearance proximal to the chronic implant, which was associated with an accumulation of autophagy cargo and a reduction in lysosomal protease level during the chronic period. Furthermore, our evidence demonstrates reactive astrocytes have myelin-containing lysosomes near the microelectrode, suggesting its role of myelin engulfment during acute implantation period. Together, this study sheds light on the process of brain tissue degeneration caused by long-term microelectrode implantation, with a specific focus on impaired intracellular waste degradation.
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Affiliation(s)
- Keying Chen
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA; Center for Neural Basis of Cognition, Pittsburgh, PA, USA
| | - Camila Garcia Padilla
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA; Center for Neural Basis of Cognition, Pittsburgh, PA, USA
| | - Kirill Kiselyov
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA, USA
| | - Takashi D Y Kozai
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA; Center for Neural Basis of Cognition, Pittsburgh, PA, USA; Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA, USA; McGowan Institute of Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA, USA; NeuroTech Center, University of Pittsburgh Brain Institute, Pittsburgh, PA, USA.
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20
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Hoeferlin GF, Bajwa T, Olivares H, Zhang J, Druschel LN, Sturgill BS, Sobota M, Boucher P, Duncan J, Hernandez-Reynoso AG, Cogan SF, Pancrazio JJ, Capadona JR. Antioxidant Dimethyl Fumarate Temporarily but Not Chronically Improves Intracortical Microelectrode Performance. MICROMACHINES 2023; 14:1902. [PMID: 37893339 PMCID: PMC10609067 DOI: 10.3390/mi14101902] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Revised: 09/24/2023] [Accepted: 10/02/2023] [Indexed: 10/29/2023]
Abstract
Intracortical microelectrode arrays (MEAs) can be used in a range of applications, from basic neuroscience research to providing an intimate interface with the brain as part of a brain-computer interface (BCI) system aimed at restoring function for people living with neurological disorders or injuries. Unfortunately, MEAs tend to fail prematurely, leading to a loss in functionality for many applications. An important contributing factor in MEA failure is oxidative stress resulting from chronically inflammatory-activated microglia and macrophages releasing reactive oxygen species (ROS) around the implant site. Antioxidants offer a means for mitigating oxidative stress and improving tissue health and MEA performance. Here, we investigate using the clinically available antioxidant dimethyl fumarate (DMF) to reduce the neuroinflammatory response and improve MEA performance in a rat MEA model. Daily treatment of DMF for 16 weeks resulted in a significant improvement in the recording capabilities of MEA devices during the sub-chronic (Weeks 5-11) phase (42% active electrode yield vs. 35% for control). However, these sub-chronic improvements were lost in the chronic implantation phase, as a more exacerbated neuroinflammatory response occurs in DMF-treated animals by 16 weeks post-implantation. Yet, neuroinflammation was indiscriminate between treatment and control groups during the sub-chronic phase. Although worse for chronic use, a temporary improvement (<12 weeks) in MEA performance is meaningful. Providing short-term improvement to MEA devices using DMF can allow for improved use for limited-duration studies. Further efforts should be taken to explore the mechanism behind a worsened neuroinflammatory response at the 16-week time point for DMF-treated animals and assess its usefulness for specific applications.
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Affiliation(s)
- George F. Hoeferlin
- Department of Biomedical Engineering, Case Western Reserve University, 10900 Euclid Ave, Cleveland, OH 44106, USA (H.O.); (J.D.)
- Advanced Platform Technology Center, Louis Stokes Cleveland Veterans Affairs Medical Center, 10701 East Blvd, Cleveland, OH 44106, USA
| | - Tejas Bajwa
- Department of Biomedical Engineering, Case Western Reserve University, 10900 Euclid Ave, Cleveland, OH 44106, USA (H.O.); (J.D.)
- Advanced Platform Technology Center, Louis Stokes Cleveland Veterans Affairs Medical Center, 10701 East Blvd, Cleveland, OH 44106, USA
| | - Hannah Olivares
- Department of Biomedical Engineering, Case Western Reserve University, 10900 Euclid Ave, Cleveland, OH 44106, USA (H.O.); (J.D.)
- Advanced Platform Technology Center, Louis Stokes Cleveland Veterans Affairs Medical Center, 10701 East Blvd, Cleveland, OH 44106, USA
| | - Jichu Zhang
- Department of Biomedical Engineering, Case Western Reserve University, 10900 Euclid Ave, Cleveland, OH 44106, USA (H.O.); (J.D.)
- Advanced Platform Technology Center, Louis Stokes Cleveland Veterans Affairs Medical Center, 10701 East Blvd, Cleveland, OH 44106, USA
| | - Lindsey N. Druschel
- Department of Biomedical Engineering, Case Western Reserve University, 10900 Euclid Ave, Cleveland, OH 44106, USA (H.O.); (J.D.)
- Advanced Platform Technology Center, Louis Stokes Cleveland Veterans Affairs Medical Center, 10701 East Blvd, Cleveland, OH 44106, USA
| | - Brandon S. Sturgill
- Department of Bioengineering, The University of Texas at Dallas, 800 W Campbell Rd, Richardson, TX 75080, USA (J.J.P.)
| | - Michael Sobota
- Department of Biomedical Engineering, Case Western Reserve University, 10900 Euclid Ave, Cleveland, OH 44106, USA (H.O.); (J.D.)
- Advanced Platform Technology Center, Louis Stokes Cleveland Veterans Affairs Medical Center, 10701 East Blvd, Cleveland, OH 44106, USA
| | - Pierce Boucher
- Department of Biomedical Engineering, Case Western Reserve University, 10900 Euclid Ave, Cleveland, OH 44106, USA (H.O.); (J.D.)
- Advanced Platform Technology Center, Louis Stokes Cleveland Veterans Affairs Medical Center, 10701 East Blvd, Cleveland, OH 44106, USA
| | - Jonathan Duncan
- Department of Biomedical Engineering, Case Western Reserve University, 10900 Euclid Ave, Cleveland, OH 44106, USA (H.O.); (J.D.)
- Advanced Platform Technology Center, Louis Stokes Cleveland Veterans Affairs Medical Center, 10701 East Blvd, Cleveland, OH 44106, USA
| | - Ana G. Hernandez-Reynoso
- Department of Bioengineering, The University of Texas at Dallas, 800 W Campbell Rd, Richardson, TX 75080, USA (J.J.P.)
| | - Stuart F. Cogan
- Department of Bioengineering, The University of Texas at Dallas, 800 W Campbell Rd, Richardson, TX 75080, USA (J.J.P.)
| | - Joseph J. Pancrazio
- Department of Bioengineering, The University of Texas at Dallas, 800 W Campbell Rd, Richardson, TX 75080, USA (J.J.P.)
| | - Jeffrey R. Capadona
- Department of Biomedical Engineering, Case Western Reserve University, 10900 Euclid Ave, Cleveland, OH 44106, USA (H.O.); (J.D.)
- Advanced Platform Technology Center, Louis Stokes Cleveland Veterans Affairs Medical Center, 10701 East Blvd, Cleveland, OH 44106, USA
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21
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Chen K, Cambi F, Kozai TDY. Pro-myelinating clemastine administration improves recording performance of chronically implanted microelectrodes and nearby neuronal health. Biomaterials 2023; 301:122210. [PMID: 37413842 PMCID: PMC10528716 DOI: 10.1016/j.biomaterials.2023.122210] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Revised: 06/08/2023] [Accepted: 06/19/2023] [Indexed: 07/08/2023]
Abstract
Intracortical microelectrodes have become a useful tool in neuroprosthetic applications in the clinic and to understand neurological disorders in basic neurosciences. Many of these brain-machine interface technology applications require successful long-term implantation with high stability and sensitivity. However, the intrinsic tissue reaction caused by implantation remains a major failure mechanism causing loss of recorded signal quality over time. Oligodendrocytes remain an underappreciated intervention target to improve chronic recording performance. These cells can accelerate action potential propagation and provides direct metabolic support for neuronal health and functionality. However, implantation injury causes oligodendrocyte degeneration and leads to progressive demyelination in surrounding brain tissue. Previous work highlighted that healthy oligodendrocytes are necessary for greater electrophysiological recording performance and the prevention of neuronal silencing around implanted microelectrodes over the chronic implantation period. Thus, we hypothesize that enhancing oligodendrocyte activity with a pharmaceutical drug, Clemastine, will prevent the chronic decline of microelectrode recording performance. Electrophysiological evaluation showed that the promyelination Clemastine treatment significantly elevated the signal detectability and quality, rescued the loss of multi-unit activity, and increased functional interlaminar connectivity over 16-weeks of implantation. Additionally, post-mortem immunohistochemistry showed that increased oligodendrocyte density and myelination coincided with increased survival of both excitatory and inhibitory neurons near the implant. Overall, we showed a positive relationship between enhanced oligodendrocyte activity and neuronal health and functionality near the chronically implanted microelectrode. This study shows that therapeutic strategy that enhance oligodendrocyte activity is effective for integrating the functional device interface with brain tissue over chronic implantation period.
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Affiliation(s)
- Keying Chen
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA; Center for Neural Basis of Cognition, Pittsburgh, PA, USA
| | - Franca Cambi
- Veterans Administration Pittsburgh, Pittsburgh, PA, USA; Department of Neurology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Takashi D Y Kozai
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA; Center for Neural Basis of Cognition, Pittsburgh, PA, USA; Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA, USA; McGowan Institute of Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA, USA; NeuroTech Center, University of Pittsburgh Brain Institute, Pittsburgh, PA, USA.
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22
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Wellman SM, Coyne OA, Douglas MM, Kozai TDY. Aberrant accumulation of age- and disease-associated factors following neural probe implantation in a mouse model of Alzheimer's disease. J Neural Eng 2023; 20:046044. [PMID: 37531953 PMCID: PMC10594264 DOI: 10.1088/1741-2552/aceca5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Revised: 07/27/2023] [Accepted: 08/01/2023] [Indexed: 08/04/2023]
Abstract
Objective. Electrical stimulation has had a profound impact on our current understanding of nervous system physiology and provided viable clinical options for addressing neurological dysfunction within the brain. Unfortunately, the brain's immune suppression of indwelling microelectrodes currently presents a major roadblock in the long-term application of neural recording and stimulating devices. In some ways, brain trauma induced by penetrating microelectrodes produces similar neuropathology as debilitating brain diseases, such as Alzheimer's disease (AD), while also suffering from end-stage neuron loss and tissue degeneration. The goal of the present study was to understand whether there may be any parallel mechanisms at play between brain injury from chronic microelectrode implantation and those of neurodegenerative disorder.Approach. We used two-photon microscopy to visualize the accumulation, if any, of age- and disease-associated factors around chronically implanted electrodes in both young and aged mouse models of AD.Main results. We determined that electrode injury leads to aberrant accumulation of lipofuscin, an age-related pigment, in wild-type and AD mice alike. Furthermore, we reveal that chronic microelectrode implantation reduces the growth of pre-existing Alzheimer's plaques while simultaneously elevating amyloid burden at the electrode-tissue interface. Lastly, we uncover novel spatial and temporal patterns of glial reactivity, axonal and myelin pathology, and neurodegeneration related to neurodegenerative disease around chronically implanted microelectrodes.Significance. This study offers multiple novel perspectives on the possible neurodegenerative mechanisms afflicting chronic brain implants, spurring new potential avenues of neuroscience investigation and design of more targeted therapies for improving neural device biocompatibility and treatment of degenerative brain disease.
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Affiliation(s)
- Steven M Wellman
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, United States of America
- Center for Neural Basis of Cognition, Pittsburgh, PA, United States of America
| | - Olivia A Coyne
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, United States of America
- Center for Neural Basis of Cognition, Pittsburgh, PA, United States of America
| | - Madeline M Douglas
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, United States of America
| | - Takashi D Y Kozai
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, United States of America
- Center for Neural Basis of Cognition, Pittsburgh, PA, United States of America
- Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA, United States of America
- McGowan Institute of Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA, United States of America
- NeuroTech Center, University of Pittsburgh Brain Institute, Pittsburgh, PA, United States of America
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23
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Lam DV, Javadekar A, Patil N, Yu M, Li L, Menendez DM, Gupta AS, Capadona JR, Shoffstall AJ. Platelets and hemostatic proteins are co-localized with chronic neuroinflammation surrounding implanted intracortical microelectrodes. Acta Biomater 2023; 166:278-290. [PMID: 37211307 PMCID: PMC10330779 DOI: 10.1016/j.actbio.2023.05.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Revised: 04/13/2023] [Accepted: 05/02/2023] [Indexed: 05/23/2023]
Abstract
Intracortical microelectrodes induce vascular injury upon insertion into the cortex. As blood vessels rupture, blood proteins and blood-derived cells (including platelets) are introduced into the 'immune privileged' brain tissues at higher-than-normal levels, passing through the damaged blood-brain barrier. Blood proteins adhere to implant surfaces, increasing the likelihood of cellular recognition leading to activation of immune and inflammatory cells. Persistent neuroinflammation is a major contributing factor to declining microelectrode recording performance. We investigated the spatial and temporal relationship of blood proteins fibrinogen and von Willebrand Factor (vWF), platelets, and type IV collagen, in relation to glial scarring markers for microglia and astrocytes following implantation of non-functional multi-shank silicon microelectrode probes into rats. Together with type IV collagen, fibrinogen and vWF augment platelet recruitment, activation, and aggregation. Our main results indicate blood proteins participating in hemostasis (fibrinogen and vWF) persisted at the microelectrode interface for up to 8-weeks after implantation. Further, type IV collagen and platelets surrounded the probe interface with similar spatial and temporal trends as vWF and fibrinogen. In addition to prolonged blood-brain barrier instability, specific blood and extracellular matrix proteins may play a role in promoting the inflammatory activation of platelets and recruitment to the microelectrode interface. STATEMENT OF SIGNIFICANCE: Implanted microelectrodes have substantial potential for restoring function to people with paralysis and amputation by providing signals that feed into natural control algorithms that drive prosthetic devices. Unfortunately, these microelectrodes do not display robust performance over time. Persistent neuroinflammation is widely thought to be a primary contributor to the devices' progressive decline in performance. Our manuscript reports on the highly local and persistent accumulation of platelets and hemostatic blood proteins around the microelectrode interface of brain implants. To our knowledge neuroinflammation driven by cellular and non-cellular responses associated with hemostasis and coagulation has not been rigorously quantified elsewhere. Our findings identify potential targets for therapeutic intervention and a better understanding of the driving mechanisms to neuroinflammation in the brain.
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Affiliation(s)
- Danny V Lam
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH 44106, USA; Advanced Platform Technology Center, Louis Stokes Cleveland VA Medical Center, Cleveland, OH, USA
| | - Anisha Javadekar
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH 44106, USA; Advanced Platform Technology Center, Louis Stokes Cleveland VA Medical Center, Cleveland, OH, USA
| | | | - Marina Yu
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Longshun Li
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH 44106, USA; Advanced Platform Technology Center, Louis Stokes Cleveland VA Medical Center, Cleveland, OH, USA
| | - Dhariyat M Menendez
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH 44106, USA; Advanced Platform Technology Center, Louis Stokes Cleveland VA Medical Center, Cleveland, OH, USA
| | - Anirban Sen Gupta
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Jeffrey R Capadona
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH 44106, USA; Advanced Platform Technology Center, Louis Stokes Cleveland VA Medical Center, Cleveland, OH, USA
| | - Andrew J Shoffstall
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH 44106, USA; Advanced Platform Technology Center, Louis Stokes Cleveland VA Medical Center, Cleveland, OH, USA.
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24
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Zhou Y, Yang H, Wang X, Yang H, Sun K, Zhou Z, Sun L, Zhao J, Tao TH, Wei X. A mosquito mouthpart-like bionic neural probe. MICROSYSTEMS & NANOENGINEERING 2023; 9:88. [PMID: 37448967 PMCID: PMC10336119 DOI: 10.1038/s41378-023-00565-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/11/2023] [Revised: 05/05/2023] [Accepted: 05/29/2023] [Indexed: 07/18/2023]
Abstract
Advancements in microscale electrode technology have revolutionized the field of neuroscience and clinical applications by offering high temporal and spatial resolution of recording and stimulation. Flexible neural probes, with their mechanical compliance to brain tissue, have been shown to be superior to rigid devices in terms of stability and longevity in chronic recordings. Shuttle devices are commonly used to assist flexible probe implantation; however, the protective membrane of the brain still makes penetration difficult. Hidden damage to brain vessels during implantation is a significant risk. Inspired by the anatomy of the mosquito mouthparts, we present a biomimetic neuroprobe system that integrates high-sensitivity sensors with a high-fidelity multichannel flexible electrode array. This customizable system achieves distributed and minimally invasive implantation across brain regions. Most importantly, the system's nonvisual monitoring capability provides an early warning detection for intracranial soft tissues, such as vessels, reducing the potential for injury during implantation. The neural probe system demonstrates exceptional sensitivity and adaptability to environmental stimuli, as well as outstanding performance in postoperative and chronic recordings. These findings suggest that our biomimetic neural-probe device offers promising potential for future applications in neuroscience and brain-machine interfaces. A mosquito mouthpart-like bionic neural probe consisting of a highly sensitive tactile sensor module, a flexible microelectrode array, and implanted modules that mimic the structure of mosquito mouthparts. The system enables distributed implantation of electrode arrays across multiple brain regions while making the implantation minimally invasive and avoiding additional dural removal. The tactile sensor array can monitor the implantation process to achieve early warning of vascular damage. The excellent postoperative short-term recording performance and long-term neural activity tracking ability demonstrate that the system is a promising tool in the field of brain-computer interfaces.
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Affiliation(s)
- Yu Zhou
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 200050 Shanghai, China
- School of Graduate Study, University of Chinese Academy of Sciences, 100049 Beijing, China
| | - Huiran Yang
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 200050 Shanghai, China
- School of Graduate Study, University of Chinese Academy of Sciences, 100049 Beijing, China
| | - Xueying Wang
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 200050 Shanghai, China
- School of Graduate Study, University of Chinese Academy of Sciences, 100049 Beijing, China
| | - Heng Yang
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 200050 Shanghai, China
- School of Graduate Study, University of Chinese Academy of Sciences, 100049 Beijing, China
| | - Ke Sun
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 200050 Shanghai, China
- School of Graduate Study, University of Chinese Academy of Sciences, 100049 Beijing, China
| | - Zhitao Zhou
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 200050 Shanghai, China
- School of Graduate Study, University of Chinese Academy of Sciences, 100049 Beijing, China
| | - Liuyang Sun
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 200050 Shanghai, China
- School of Graduate Study, University of Chinese Academy of Sciences, 100049 Beijing, China
- 2020 X-Lab, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 200050 Shanghai, China
| | - Jianlong Zhao
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 200050 Shanghai, China
- School of Graduate Study, University of Chinese Academy of Sciences, 100049 Beijing, China
| | - Tiger H. Tao
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 200050 Shanghai, China
- School of Graduate Study, University of Chinese Academy of Sciences, 100049 Beijing, China
- 2020 X-Lab, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 200050 Shanghai, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, 100049 Beijing, China
- Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, 200031 Shanghai, China
- Neuroxess Co., Ltd. (Jiangxi), 330029 Nanchang, Jiangxi China
- Guangdong Institute of Intelligence Science and Technology, Hengqin, 519031 Zhuhai, Guangdong China
- Tianqiao and Chrissy Chen Institute for Translational Research, Shanghai, China
| | - Xiaoling Wei
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 200050 Shanghai, China
- School of Graduate Study, University of Chinese Academy of Sciences, 100049 Beijing, China
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25
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Smith TJ, Wu Y, Cheon C, Khan AA, Srinivasan H, Capadona JR, Cogan SF, Pancrazio JJ, Engineer CT, Hernandez-Reynoso AG. Behavioral paradigm for the evaluation of stimulation-evoked somatosensory perception thresholds in rats. Front Neurosci 2023; 17:1202258. [PMID: 37383105 PMCID: PMC10293669 DOI: 10.3389/fnins.2023.1202258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2023] [Accepted: 05/22/2023] [Indexed: 06/30/2023] Open
Abstract
Intracortical microstimulation (ICMS) of the somatosensory cortex via penetrating microelectrode arrays (MEAs) can evoke cutaneous and proprioceptive sensations for restoration of perception in individuals with spinal cord injuries. However, ICMS current amplitudes needed to evoke these sensory percepts tend to change over time following implantation. Animal models have been used to investigate the mechanisms by which these changes occur and aid in the development of new engineering strategies to mitigate such changes. Non-human primates are commonly the animal of choice for investigating ICMS, but ethical concerns exist regarding their use. Rodents are a preferred animal model due to their availability, affordability, and ease of handling, but there are limited choices of behavioral tasks for investigating ICMS. In this study, we investigated the application of an innovative behavioral go/no-go paradigm capable of estimating ICMS-evoked sensory perception thresholds in freely moving rats. We divided animals into two groups, one receiving ICMS and a control group receiving auditory tones. Then, we trained the animals to nose-poke - a well-established behavioral task for rats - following either a suprathreshold ICMS current-controlled pulse train or frequency-controlled auditory tone. Animals received a sugar pellet reward when nose-poking correctly. When nose-poking incorrectly, animals received a mild air puff. After animals became proficient in this task, as defined by accuracy, precision, and other performance metrics, they continued to the next phase for perception threshold detection, where we varied the ICMS amplitude using a modified staircase method. Finally, we used non-linear regression to estimate perception thresholds. Results indicated that our behavioral protocol could estimate ICMS perception thresholds based on ~95% accuracy of rat nose-poke responses to the conditioned stimulus. This behavioral paradigm provides a robust methodology for evaluating stimulation-evoked somatosensory percepts in rats comparable to the evaluation of auditory percepts. In future studies, this validated methodology can be used to study the performance of novel MEA device technologies on ICMS-evoked perception threshold stability using freely moving rats or to investigate information processing principles in neural circuits related to sensory perception discrimination.
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Affiliation(s)
- Thomas J. Smith
- School of Behavioral and Brain Sciences, The University of Texas at Dallas, Richardson, TX, United States
| | - Yupeng Wu
- Department of Materials Science and Engineering, The University of Texas at Dallas, Richardson, TX, United States
| | - Claire Cheon
- Department of Bioengineering, The University of Texas at Dallas, Richardson, TX, United States
| | - Arlin A. Khan
- School of Behavioral and Brain Sciences, The University of Texas at Dallas, Richardson, TX, United States
| | - Hari Srinivasan
- School of Behavioral and Brain Sciences, The University of Texas at Dallas, Richardson, TX, United States
| | - Jeffrey R. Capadona
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States
- Advanced Platform Technology Center, Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland, OH, United States
| | - Stuart F. Cogan
- Department of Bioengineering, The University of Texas at Dallas, Richardson, TX, United States
| | - Joseph J. Pancrazio
- Department of Bioengineering, The University of Texas at Dallas, Richardson, TX, United States
| | - Crystal T. Engineer
- School of Behavioral and Brain Sciences, The University of Texas at Dallas, Richardson, TX, United States
- Texas Biomedical Device Center, The University of Texas at Dallas, Richardson, TX, United States
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26
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Franklin ME, Bennett C, Arboite M, Alvarez-Ciara A, Corrales N, Verdelus J, Dietrich WD, Keane RW, de Rivero Vaccari JP, Prasad A. Activation of inflammasomes and their effects on neuroinflammation at the microelectrode-tissue interface in intracortical implants. Biomaterials 2023; 297:122102. [PMID: 37015177 PMCID: PMC10614166 DOI: 10.1016/j.biomaterials.2023.122102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Revised: 03/16/2023] [Accepted: 03/23/2023] [Indexed: 03/30/2023]
Abstract
Invasive neuroprosthetics rely on microelectrodes (MEs) to record or stimulate the activity of large neuron assemblies. However, MEs are subjected to tissue reactivity in the central nervous system (CNS) due to the foreign body response (FBR) that contribute to chronic neuroinflammation and ultimately result in ME failure. An endogenous, acute set of mechanisms responsible for the recognition and targeting of foreign objects, called the innate immune response, immediately follows the ME implant-induced trauma. Inflammasomes are multiprotein structures that play a critical role in the initiation of an innate immune response following CNS injuries. The activation of inflammasomes facilitates a range of innate immune response cascades and results in neuroinflammation and programmed cell death. Despite our current understanding of inflammasomes, their roles in the context of neural device implantation remain unknown. In this study, we implanted a non-functional Utah electrode array (UEA) into the rat somatosensory cortex and studied the inflammasome signaling and the corresponding downstream effects on inflammatory cytokine expression and the inflammasome-mediated cell death mechanism of pyroptosis. Our results not only demonstrate the continuous activation of inflammasomes and their contribution to neuroinflammation at the electrode-tissue interface but also reveal the therapeutic potential of targeting inflammasomes to attenuate the FBR in invasive neuroprosthetics.
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Affiliation(s)
- Melissa E Franklin
- Department of Biomedical Engineering, University of Miami, Miami, FL, USA
| | - Cassie Bennett
- Department of Biomedical Engineering, University of Miami, Miami, FL, USA
| | - Maelle Arboite
- Department of Biomedical Engineering, University of Miami, Miami, FL, USA
| | | | - Natalie Corrales
- Department of Biomedical Engineering, University of Miami, Miami, FL, USA
| | - Jennifer Verdelus
- Department of Biomedical Engineering, University of Miami, Miami, FL, USA
| | - W Dalton Dietrich
- Department of Biomedical Engineering, University of Miami, Miami, FL, USA; Department of Neurological Surgery, University of Miami Miller School of Medicine, Miami, FL, USA; The Miami Project to Cure Paralysis, University of Miami, Miami, FL, USA
| | - Robert W Keane
- The Miami Project to Cure Paralysis, University of Miami, Miami, FL, USA; Department of Physiology and Biophysics, University of Miami Miller School of Medicine, Miami, FL, USA; Center for Cognitive Neuroscience and Aging University of Miami Miller School of Medicine, Miami, FL, USA
| | - Juan Pablo de Rivero Vaccari
- The Miami Project to Cure Paralysis, University of Miami, Miami, FL, USA; Department of Physiology and Biophysics, University of Miami Miller School of Medicine, Miami, FL, USA; Center for Cognitive Neuroscience and Aging University of Miami Miller School of Medicine, Miami, FL, USA
| | - Abhishek Prasad
- Department of Biomedical Engineering, University of Miami, Miami, FL, USA; The Miami Project to Cure Paralysis, University of Miami, Miami, FL, USA.
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27
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Smith TJ, Wu Y, Cheon C, Khan AA, Srinivasan H, Capadona JR, Cogan SF, Pancrazio JJ, Engineer CT, Hernandez-Reynoso AG. Behavioral Paradigm for the Evaluation of Stimulation-Evoked Somatosensory Perception Thresholds in Rats. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.04.537848. [PMID: 37205577 PMCID: PMC10187227 DOI: 10.1101/2023.05.04.537848] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Intracortical microstimulation (ICMS) of the somatosensory cortex via penetrating microelectrode arrays (MEAs) can evoke cutaneous and proprioceptive sensations for restoration of perception in individuals with spinal cord injuries. However, ICMS current amplitudes needed to evoke these sensory percepts tend to change over time following implantation. Animal models have been used to investigate the mechanisms by which these changes occur and aid in the development of new engineering strategies to mitigate such changes. Non-human primates are commonly the animal of choice for investigating ICMS, but ethical concerns exist regarding their use. Rodents are a preferred animal model due to their availability, affordability, and ease of handling, but there are limited choices of behavioral tasks for investigating ICMS. In this study, we investigated the application of an innovative behavioral go/no-go paradigm capable of estimating ICMS-evoked sensory perception thresholds in freely moving rats. We divided animals into two groups, one receiving ICMS and a control group receiving auditory tones. Then, we trained the animals to nose-poke - a well-established behavioral task for rats - following either a suprathreshold ICMS current-controlled pulse train or frequency-controlled auditory tone. Animals received a sugar pellet reward when nose-poking correctly. When nose-poking incorrectly, animals received a mild air puff. After animals became proficient in this task, as defined by accuracy, precision, and other performance metrics, they continued to the next phase for perception threshold detection, where we varied the ICMS amplitude using a modified staircase method. Finally, we used non-linear regression to estimate perception thresholds. Results indicated that our behavioral protocol could estimate ICMS perception thresholds based on ∼95% accuracy of rat nose-poke responses to the conditioned stimulus. This behavioral paradigm provides a robust methodology for evaluating stimulation-evoked somatosensory percepts in rats comparable to the evaluation of auditory percepts. In future studies, this validated methodology can be used to study the performance of novel MEA device technologies on ICMS-evoked perception threshold stability using freely moving rats or to investigate information processing principles in neural circuits related to sensory perception discrimination.
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28
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Letner JG, Patel PR, Hsieh JC, Smith Flores IM, della Valle E, Walker LA, Weiland JD, Chestek CA, Cai D. Post-explant profiling of subcellular-scale carbon fiber intracortical electrodes and surrounding neurons enables modeling of recorded electrophysiology. J Neural Eng 2023; 20:026019. [PMID: 36848679 PMCID: PMC10022369 DOI: 10.1088/1741-2552/acbf78] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Revised: 01/12/2023] [Accepted: 02/27/2023] [Indexed: 03/01/2023]
Abstract
Objective.Characterizing the relationship between neuron spiking and the signals that electrodes record is vital to defining the neural circuits driving brain function and informing clinical brain-machine interface design. However, high electrode biocompatibility and precisely localizing neurons around the electrodes are critical to defining this relationship.Approach.Here, we demonstrate consistent localization of the recording site tips of subcellular-scale (6.8µm diameter) carbon fiber electrodes and the positions of surrounding neurons. We implanted male rats with carbon fiber electrode arrays for 6 or 12+ weeks targeting layer V motor cortex. After explanting the arrays, we immunostained the implant site and localized putative recording site tips with subcellular-cellular resolution. We then 3D segmented neuron somata within a 50µm radius from implanted tips to measure neuron positions and health and compare to healthy cortex with symmetric stereotaxic coordinates.Main results.Immunostaining of astrocyte, microglia, and neuron markers confirmed that overall tissue health was indicative of high biocompatibility near the tips. While neurons near implanted carbon fibers were stretched, their number and distribution were similar to hypothetical fibers placed in healthy contralateral brain. Such similar neuron distributions suggest that these minimally invasive electrodes demonstrate the potential to sample naturalistic neural populations. This motivated the prediction of spikes produced by nearby neurons using a simple point source model fit using recorded electrophysiology and the mean positions of the nearest neurons observed in histology. Comparing spike amplitudes suggests that the radius at which single units can be distinguished from others is near the fourth closest neuron (30.7 ± 4.6µm,X-± S) in layer V motor cortex.Significance.Collectively, these data and simulations provide the first direct evidence that neuron placement in the immediate vicinity of the recording site influences how many spike clusters can be reliably identified by spike sorting.
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Affiliation(s)
- Joseph G Letner
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109, United States of America
- Biointerfaces Institute, University of Michigan, Ann Arbor, MI 48109, United States of America
| | - Paras R Patel
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109, United States of America
- Biointerfaces Institute, University of Michigan, Ann Arbor, MI 48109, United States of America
| | - Jung-Chien Hsieh
- Neuroscience Graduate Program, University of Michigan, Ann Arbor, MI 48109, United States of America
| | - Israel M Smith Flores
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109, United States of America
- Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, MI 48109, United States of America
| | - Elena della Valle
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109, United States of America
- Biointerfaces Institute, University of Michigan, Ann Arbor, MI 48109, United States of America
| | - Logan A Walker
- Biophysics Program, University of Michigan, Ann Arbor, MI 48109, United States of America
- Department of Computational Medicine and Bioinformatics, Michigan Medicine, Ann Arbor, MI 48109, United States of America
| | - James D Weiland
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109, United States of America
- Biointerfaces Institute, University of Michigan, Ann Arbor, MI 48109, United States of America
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan, Ann Arbor, MI 48105, United States of America
| | - Cynthia A Chestek
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109, United States of America
- Biointerfaces Institute, University of Michigan, Ann Arbor, MI 48109, United States of America
- Neuroscience Graduate Program, University of Michigan, Ann Arbor, MI 48109, United States of America
- Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, MI 48109, United States of America
- Robotics Department, University of Michigan, Ann Arbor, MI 48109, United States of America
| | - Dawen Cai
- Neuroscience Graduate Program, University of Michigan, Ann Arbor, MI 48109, United States of America
- Biophysics Program, University of Michigan, Ann Arbor, MI 48109, United States of America
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI 48109, United States of America
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Wellman SM, Coyne OA, Douglas MM, Kozai TDY. Aberrant accumulation of age- and disease-associated factors following neural probe implantation in a mouse model of Alzheimer's disease. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.11.528131. [PMID: 36891286 PMCID: PMC9993955 DOI: 10.1101/2023.02.11.528131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
Electrical stimulation has had a profound impact on our current understanding of nervous system physiology and provided viable clinical options for addressing neurological dysfunction within the brain. Unfortunately, the brain's immune suppression of indwelling microelectrodes currently presents a major roadblock in the long-term application of neural recording and stimulating devices. In some ways, brain trauma induced by penetrating microelectrodes produces similar neuropathology as debilitating brain diseases, such as Alzheimer's disease (AD), while also suffering from end-stage neuron loss and tissue degeneration. To understand whether there may be any parallel mechanisms at play between brain injury from chronic microelectrode implantation and those of neurodegenerative disorder, we used two-photon microscopy to visualize the accumulation, if any, of age- and disease-associated factors around chronically implanted electrodes in both young and aged mouse models of AD. With this approach, we determined that electrode injury leads to aberrant accumulation of lipofuscin, an age-related pigment, in wild-type and AD mice alike. Furthermore, we reveal that chronic microelectrode implantation reduces the growth of pre-existing amyloid plaques while simultaneously elevating amyloid burden at the electrode-tissue interface. Lastly, we uncover novel spatial and temporal patterns of glial reactivity, axonal and myelin pathology, and neurodegeneration related to neurodegenerative disease around chronically implanted microelectrodes. This study offers multiple novel perspectives on the possible neurodegenerative mechanisms afflicting chronic brain implants, spurring new potential avenues of neuroscience investigation and design of more targeted therapies for improving neural device biocompatibility and treatment of degenerative brain disease.
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Chen K, Cambi F, Kozai TDY. Pro-myelinating Clemastine administration improves recording performance of chronically implanted microelectrodes and nearby neuronal health. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.31.526463. [PMID: 36778360 PMCID: PMC9915570 DOI: 10.1101/2023.01.31.526463] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Intracortical microelectrodes have become a useful tool in neuroprosthetic applications in the clinic and to understand neurological disorders in basic neurosciences. Many of these brain-machine interface technology applications require successful long-term implantation with high stability and sensitivity. However, the intrinsic tissue reaction caused by implantation remains a major failure mechanism causing loss of recorded signal quality over time. Oligodendrocytes remain an underappreciated intervention target to improve chronic recording performance. These cells can accelerate action potential propagation and provides direct metabolic support for neuronal health and functionality. However, implantation injury causes oligodendrocyte degeneration and leads to progressive demyelination in surrounding brain tissue. Previous work highlighted that healthy oligodendrocytes are necessary for greater electrophysiological recording performance and the prevention of neuronal silencing around implanted microelectrodes over chronic implantation. Thus, we hypothesize that enhancing oligodendrocyte activity with a pharmaceutical drug, Clemastine, will prevent the chronic decline of microelectrode recording performance. Electrophysiological evaluation showed that the promyelination Clemastine treatment significantly elevated the signal detectability and quality, rescued the loss of multi-unit activity, and increased functional interlaminar connectivity over 16-weeks of implantation. Additionally, post-mortem immunohistochemistry showed that increased oligodendrocyte density and myelination coincided with increased survival of both excitatory and inhibitory neurons near the implant. Overall, we showed a positive relationship between enhanced oligodendrocyte activity and neuronal health and functionality near the chronically implanted microelectrode. This study shows that therapeutic strategy that enhance oligodendrocyte activity is effective for integrating the functional device interface with brain tissue over chronic implantation period. Abstract Figure
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31
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Zhang Y, Wu X, Vadlamani RA, Lim Y, Kim J, David K, Gilbert E, Li Y, Wang R, Jiang S, Wang A, Sontheimer H, English D, Emori S, Davalos RV, Poelzing S, Jia X. Multifunctional ferromagnetic fiber robots for navigation, sensing, and treatment in minimally invasive surgery. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.27.525973. [PMID: 36778450 PMCID: PMC9915472 DOI: 10.1101/2023.01.27.525973] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Small-scale robots capable of remote active steering and navigation offer great potential for biomedical applications. However, the current design and manufacturing procedure impede their miniaturization and integration of various diagnostic and therapeutic functionalities. Here, we present a robotic fiber platform for integrating navigation, sensing, and therapeutic functions at a submillimeter scale. These fiber robots consist of ferromagnetic, electrical, optical, and microfluidic components, fabricated with a thermal drawing process. Under magnetic actuation, they can navigate through complex and constrained environments, such as artificial vessels and brain phantoms. Moreover, we utilize Langendorff mouse hearts model, glioblastoma microplatforms, and in vivo mouse models to demonstrate the capabilities of sensing electrophysiology signals and performing localized treatment. Additionally, we demonstrate that the fiber robots can serve as endoscopes with embedded waveguides. These fiber robots provide a versatile platform for targeted multimodal detection and treatment at hard-to-reach locations in a minimally invasive and remotely controllable manner.
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Affiliation(s)
- Yujing Zhang
- The Bradley Department of Electrical and Computer Engineering, Virginia Tech, Blacksburg, VA
| | - Xiaobo Wu
- Translational Biology, Medicine, and Health Graduate Program, Virginia Tech, Roanoke, VA
- Center for Heart and Reparative Medicine Research, Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, VA
| | - Ram Anand Vadlamani
- Department of Biomedical Engineering and Mechanics, Virginia Tech, Blacksburg, VA
| | - Youngmin Lim
- Department of Physics, Virginia Tech, Blacksburg, VA
| | - Jongwoon Kim
- The Bradley Department of Electrical and Computer Engineering, Virginia Tech, Blacksburg, VA
| | - Kailee David
- Department of Biomedical Engineering and Mechanics, Virginia Tech, Blacksburg, VA
| | - Earl Gilbert
- School of Neuroscience, Virginia Tech, Blacksburg, VA
| | - You Li
- The Bradley Department of Electrical and Computer Engineering, Virginia Tech, Blacksburg, VA
| | - Ruixuan Wang
- The Bradley Department of Electrical and Computer Engineering, Virginia Tech, Blacksburg, VA
| | - Shan Jiang
- The Bradley Department of Electrical and Computer Engineering, Virginia Tech, Blacksburg, VA
| | - Anbo Wang
- The Bradley Department of Electrical and Computer Engineering, Virginia Tech, Blacksburg, VA
| | - Harald Sontheimer
- Department of Neuroscience, University of Virginia School of Medicine, Charlottesville, VA
| | | | - Satoru Emori
- Department of Physics, Virginia Tech, Blacksburg, VA
| | - Rafael V. Davalos
- Department of Biomedical Engineering and Mechanics, Virginia Tech, Blacksburg, VA
| | - Steven Poelzing
- Translational Biology, Medicine, and Health Graduate Program, Virginia Tech, Roanoke, VA
- Center for Heart and Reparative Medicine Research, Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, VA
- Department of Biomedical Engineering and Mechanics, Virginia Tech, Blacksburg, VA
| | - Xiaoting Jia
- The Bradley Department of Electrical and Computer Engineering, Virginia Tech, Blacksburg, VA
- School of Neuroscience, Virginia Tech, Blacksburg, VA
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Savya SP, Li F, Lam S, Wellman SM, Stieger KC, Chen K, Eles JR, Kozai TDY. In vivo spatiotemporal dynamics of astrocyte reactivity following neural electrode implantation. Biomaterials 2022; 289:121784. [PMID: 36103781 PMCID: PMC10231871 DOI: 10.1016/j.biomaterials.2022.121784] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Revised: 08/24/2022] [Accepted: 08/29/2022] [Indexed: 11/02/2022]
Abstract
Brain computer interfaces (BCIs), including penetrating microelectrode arrays, enable both recording and stimulation of neural cells. However, device implantation inevitably causes injury to brain tissue and induces a foreign body response, leading to reduced recording performance and stimulation efficacy. Astrocytes in the healthy brain play multiple roles including regulating energy metabolism, homeostatic balance, transmission of neural signals, and neurovascular coupling. Following an insult to the brain, they are activated and gather around the site of injury. These reactive astrocytes have been regarded as one of the main contributors to the formation of a glial scar which affects the performance of microelectrode arrays. This study investigates the dynamics of astrocytes within the first 2 weeks after implantation of an intracortical microelectrode into the mouse brain using two-photon microscopy. From our observation astrocytes are highly dynamic during this period, exhibiting patterns of process extension, soma migration, morphological activation, and device encapsulation that are spatiotemporally distinct from other glial cells, such as microglia or oligodendrocyte precursor cells. This detailed characterization of astrocyte reactivity will help to better understand the tissue response to intracortical devices and lead to the development of more effective intervention strategies to improve the functional performance of neural interfacing technology.
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Affiliation(s)
- Sajishnu P Savya
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA; Northwestern University, USA
| | - Fan Li
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA; Center for Neural Basis of Cognition, University of Pittsburgh, Pittsburgh, PA, USA; Computational Modeling & Simulation PhD Program, University of Pittsburgh, Pittsburgh, PA, USA
| | - Stephanie Lam
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA; Center for Neural Basis of Cognition, University of Pittsburgh, Pittsburgh, PA, USA
| | - Steven M Wellman
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA; Center for Neural Basis of Cognition, University of Pittsburgh, Pittsburgh, PA, USA
| | - Kevin C Stieger
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA; Center for Neural Basis of Cognition, University of Pittsburgh, Pittsburgh, PA, USA
| | - Keying Chen
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA; Center for Neural Basis of Cognition, University of Pittsburgh, Pittsburgh, PA, USA
| | - James R Eles
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA; Center for Neural Basis of Cognition, University of Pittsburgh, Pittsburgh, PA, USA
| | - Takashi D Y Kozai
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA; Center for Neural Basis of Cognition, University of Pittsburgh, Pittsburgh, PA, USA; Center for Neuroscience, University of Pittsburgh, University of Pittsburgh, Pittsburgh, PA, USA; McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA, USA; NeuroTech Center, University of Pittsburgh Brain Institute, Pittsburgh, PA, USA.
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Kushwah N, Woeppel K, Dhawan V, Shi D, Cui XT. Effects of neuronal cell adhesion molecule L1 and nanoparticle surface modification on microglia. Acta Biomater 2022; 149:273-286. [PMID: 35764240 PMCID: PMC10018678 DOI: 10.1016/j.actbio.2022.06.038] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2022] [Revised: 06/20/2022] [Accepted: 06/21/2022] [Indexed: 11/19/2022]
Abstract
Microelectrode arrays for neural recording suffer from low yield and stability partly due to the inflammatory host responses. A neuronal cell adhesion molecule L1 coating has been shown to promote electrode-neuron integration, reduce microglia activation and improve recording. Coupling L1 to surface via a nanoparticle (NP) base layer further increased the protein surface density and stability. However, the exact L1-microglia interaction in these coatings has not been studied. Here we cultured primary microglia on L1 modified surfaces (with and without NP) and characterized microglia activation upon phorbol myristate acetate (PMA) and lipopolysaccharide (LPS) stimulation. Results showed L1 coatings reduced microglia's superoxide production in response to PMA and presented intrinsic antioxidant properties. Meanwhile, L1 decreased iNOS, NO, and pro-inflammatory cytokines (TNF alpha, IL-6, IL-1 beta), while increased anti-inflammatory cytokines (TGF beta 1, IL-10) in LPS stimulated microglia. Furthermore, L1 increased Arg-1 expression and phagocytosis upon LPS stimulation. Rougher NP surface showed lower number of microglia attached per area than their smooth counterpart, lower IL-6 release and superoxide production, and higher intrinsic reducing potential. Finally, we examined the effect of L1 and nanoparticle modifications on microglia response in vivo over 8 weeks with 2-photon imaging. Microglial coverage on the implant surface was found to be lower on the L1 modified substrates relative to unmodified, consistent with the in vitro observation. Our results indicate L1 significantly reduces superoxide production and inflammatory response of microglia and promotes wound healing, while L1 immobilization via a nanoparticle base layer brings added benefit without adverse effects. STATEMENT OF SIGNIFICANCE: Surface modification of microelectrode arrays with L1 has been shown to reduce microglia coverage on neural probe surface in vivo and improves neural recording, but the specific mechanism of action is not fully understood. The results in this study show that surface bound L1 reduces superoxide production from cultured microglia via direct reduction reaction and signaling pathways, increases anti-inflammatory cytokine release and phagocytosis in response to PMA or LPS stimulation. Additionally, roughening the surface with nanoparticles prior to L1 immobilization further increased the benefit of L1 in reducing microglia activation and oxidative stress. Together, our findings shed light on the mechanisms of action of nanotextured and neuroadhesive neural implant coatings and guide future development of seamless tissue interface.
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Affiliation(s)
- Neetu Kushwah
- Neural Tissue/Electrode Interface and Neural Tissue Engineering lab, Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA 15260, United States
| | - Kevin Woeppel
- Neural Tissue/Electrode Interface and Neural Tissue Engineering lab, Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA 15260, United States; Center for Neural Basis of Cognition, Pittsburgh, PA 15213, United States
| | - Vaishnavi Dhawan
- Neural Tissue/Electrode Interface and Neural Tissue Engineering lab, Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA 15260, United States; Center for Neural Basis of Cognition, Pittsburgh, PA 15213, United States
| | - Delin Shi
- Neural Tissue/Electrode Interface and Neural Tissue Engineering lab, Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA 15260, United States; Center for Neural Basis of Cognition, Pittsburgh, PA 15213, United States
| | - Xinyan Tracy Cui
- Neural Tissue/Electrode Interface and Neural Tissue Engineering lab, Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA 15260, United States; McGowan Institute for Regenerative Medicine, Pittsburgh, PA 15219, United States; Center for Neural Basis of Cognition, Pittsburgh, PA 15213, United States.
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Dhawan V, Cui XT. Carbohydrate based biomaterials for neural interface applications. J Mater Chem B 2022; 10:4714-4740. [PMID: 35702979 DOI: 10.1039/d2tb00584k] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Neuroprosthetic devices that record and modulate neural activities have demonstrated immense potential for bypassing or restoring lost neurological functions due to neural injuries and disorders. However, implantable electrical devices interfacing with brain tissue are susceptible to a series of inflammatory tissue responses along with mechanical or electrical failures which can affect the device performance over time. Several biomaterial strategies have been implemented to improve device-tissue integration for high quality and stable performance. Ranging from developing smaller, softer, and more flexible electrode designs to introducing bioactive coatings and drug-eluting layers on the electrode surface, such strategies have shown different degrees of success but with limitations. With their hydrophilic properties and specific bioactivities, carbohydrates offer a potential solution for addressing some of the limitations of the existing biomolecular approaches. In this review, we summarize the role of polysaccharides in the central nervous system, with a primary focus on glycoproteins and proteoglycans, to shed light on their untapped potential as biomaterials for neural implants. Utilization of glycosaminoglycans for neural interface and tissue regeneration applications is comprehensively reviewed to provide the current state of carbohydrate-based biomaterials for neural implants. Finally, we will discuss the challenges and opportunities of applying carbohydrate-based biomaterials for neural tissue interfaces.
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Affiliation(s)
- Vaishnavi Dhawan
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA. .,Center for Neural Basis of Cognition, Pittsburgh, PA, USA
| | - Xinyan Tracy Cui
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA. .,Center for Neural Basis of Cognition, Pittsburgh, PA, USA.,McGowan Institute for Regenerative Medicine, Pittsburgh, PA, USA
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Kim Y, Alimperti S, Choi P, Noh M. An Inkjet Printed Flexible Electrocorticography (ECoG) Microelectrode Array on a Thin Parylene-C Film. SENSORS (BASEL, SWITZERLAND) 2022; 22:1277. [PMID: 35162023 PMCID: PMC8838719 DOI: 10.3390/s22031277] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Revised: 01/08/2022] [Accepted: 01/10/2022] [Indexed: 11/16/2022]
Abstract
Electrocorticography (ECoG) is a conventional, invasive technique for recording brain signals from the cortical surface using an array of electrodes. In this study, we developed a highly flexible 22-channel ECoG microelectrode array on a thin Parylene film using novel fabrication techniques. Narrow (<40 µm) and thin (<500 nm) microelectrode patterns were first printed on PDMS, then the patterns were transferred onto Parylene films via vapor deposition and peeling. A custom-designed, 3D-printed connector was built and assembled with the Parylene-based flexible ECoG microelectrode array without soldering. The impedance of the assembled ECoG electrode array was measured in vitro by electrochemical impedance spectroscopy, and the result was consistent. In addition, we conducted in vivo studies by implanting the flexible ECoG sensor in a rat and successfully recording brain signals.
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Affiliation(s)
- Yoontae Kim
- American Dental Association Science & Research Institute, Gaithersburg, MD 20899, USA; (Y.K.); (S.A.)
| | - Stella Alimperti
- American Dental Association Science & Research Institute, Gaithersburg, MD 20899, USA; (Y.K.); (S.A.)
| | - Paul Choi
- Department of Electrical and Computer Engineering, University of Texas Rio Grande Valley, Edinburg, TX 78539, USA;
| | - Moses Noh
- Department of Mechanical Engineering and Mechanics, Drexel University, Philadelphia, PA 19104, USA
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Racz RR, Kollo M, Racz G, Bulz C, Ackels T, Warner T, Wray W, Kiskin N, Chen C, Ye Z, de Hoz L, Rancz E, Schaefer AT. jULIEs: nanostructured polytrodes for low traumatic extracellular recordings and stimulation in the mammalian brain. J Neural Eng 2022; 19. [PMID: 35108701 DOI: 10.1088/1741-2552/ac514f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Accepted: 02/02/2022] [Indexed: 11/11/2022]
Abstract
Objective Extracellular microelectrode techniques are the most widely used approach to interrogate neuronal populations. Regardless of the manufacturing method, damage to the vasculature and circuit function during probe insertion remains a concern. Reducing the footprint of the penetrating probes is a potential solution to this issue. However, coupling to the extracellular signals requires careful surface engineering. Approach Here, we show that continuously drawn SiO2-insulated ultra-microelectrode fibres offer an attractive substrate to address these challenges. Individual fibres can be fabricated to >10m continuous stretches and a selection of diameters below 30 µm with a low resistance (<100 Ω/m), continuous metal core of <10 µm and atomically flat smooth shank surfaces. To optimize the properties of the miniaturised electrode-tissue interface, we electrodeposit rough Au structures followed by ~20nm IrOx film by electrodeposition resulting in reduction of the interfacial impedance to <500kΩ at 1 kHz. Main results We demonstrate that these ultra-low impedance electrodes (jULIEs) can record and stimulate single and multi-unit activity with minimal tissue disturbance and exceptional signal-to-noise ratio in both superficial (~40µm) and deep (~6mm) structures of the mouse brain. We further show that sensor modifications are stable and probe manufacturing is reproducible. Significance Minimally perturbing bidirectional neural interfacing can reveal circuit function in the mammalian brain in vivo.
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Affiliation(s)
- Romeo Robert Racz
- Neurophysiology, The Francis Crick Institute, 1 MIdland Road, London, London, NW1 1AT, UNITED KINGDOM OF GREAT BRITAIN AND NORTHERN IRELAND
| | - Mihaly Kollo
- The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UNITED KINGDOM OF GREAT BRITAIN AND NORTHERN IRELAND
| | - Gabriella Racz
- The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UNITED KINGDOM OF GREAT BRITAIN AND NORTHERN IRELAND
| | - Ciprian Bulz
- University of Southampton, University Road, Southampton, Hampshire, SO17 1BJ, UNITED KINGDOM OF GREAT BRITAIN AND NORTHERN IRELAND
| | - Tobias Ackels
- The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UNITED KINGDOM OF GREAT BRITAIN AND NORTHERN IRELAND
| | - Tom Warner
- The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UNITED KINGDOM OF GREAT BRITAIN AND NORTHERN IRELAND
| | - William Wray
- The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UNITED KINGDOM OF GREAT BRITAIN AND NORTHERN IRELAND
| | - Nikolai Kiskin
- Department of Bioengineering, Imperial College London, Exhibition Road, London, London, SW7 2AZ, UNITED KINGDOM OF GREAT BRITAIN AND NORTHERN IRELAND
| | - Chi Chen
- Department of Neurogenetics, Charité Universitätsmedizin Berlin, Hermann-Rein-Straße 3, Berlin, Berlin, 10117, GERMANY
| | - Zhiwen Ye
- University of Washington, 1959 NE Pacific St., Seattle, Washington, 98195-7420, UNITED STATES
| | - Livia de Hoz
- Neuroscience Research Center, Charité Universitätsmedizin Berlin, Virchowweg 6, Berlin, Berlin, 10117, GERMANY
| | - Ede Rancz
- The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UNITED KINGDOM OF GREAT BRITAIN AND NORTHERN IRELAND
| | - Andreas T Schaefer
- The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UNITED KINGDOM OF GREAT BRITAIN AND NORTHERN IRELAND
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Otte E, Vlachos A, Asplund M. Engineering strategies towards overcoming bleeding and glial scar formation around neural probes. Cell Tissue Res 2022; 387:461-477. [PMID: 35029757 PMCID: PMC8975777 DOI: 10.1007/s00441-021-03567-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Accepted: 12/17/2021] [Indexed: 12/15/2022]
Abstract
Neural probes are sophisticated electrophysiological tools used for intra-cortical recording and stimulation. These microelectrode arrays, designed to penetrate and interface the brain from within, contribute at the forefront of basic and clinical neuroscience. However, one of the challenges and currently most significant limitations is their ‘seamless’ long-term integration into the surrounding brain tissue. Following implantation, which is typically accompanied by bleeding, the tissue responds with a scarring process, resulting in a gliotic region closest to the probe. This glial scarring is often associated with neuroinflammation, neurodegeneration, and a leaky blood–brain interface (BBI). The engineering progress on minimizing this reaction in the form of improved materials, microfabrication, and surgical techniques is summarized in this review. As research over the past decade has progressed towards a more detailed understanding of the nature of this biological response, it is time to pose the question: Are penetrating probes completely free from glial scarring at all possible?
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Jang JW, Kang YN, Seo HW, Kim B, Choe HK, Park SH, Lee MG, Kim S. Long-term in-vivorecording performance of flexible penetrating microelectrode arrays. J Neural Eng 2021; 18. [PMID: 34795067 DOI: 10.1088/1741-2552/ac3656] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Accepted: 11/02/2021] [Indexed: 11/12/2022]
Abstract
Objective. Neural interfaces are an essential tool to enable the human body to directly communicate with machines such as computers or prosthetic robotic arms. Since invasive electrodes can be located closer to target neurons, they have advantages such as precision in stimulation and high signal-to-noise ratio (SNR) in recording, while they often exhibit unstable performance in long-termin-vivoimplantation because of the tissue damage caused by the electrodes insertion. In the present study, we investigated the electrical functionality of flexible penetrating microelectrode arrays (FPMAs) up to 3 months inin-vivoconditions.Approach. Thein-vivoexperiment was performed by implanting FPMAs in five rats. Thein-vivoimpedance as well as the action potential (AP) amplitude and SNR were analyzed over weeks. Additionally, APs were tracked over time to investigate the possibility of single neuron recording.Main results. It was observed that the FPMAs exhibited dramatic increases in impedance for the first 4 weeks after implantation, accompanied by decreases in AP amplitude. However, the increase/decrease in AP amplitude was always accompanied by the increase/decrease in background noise, resulting in quite consistently maintained SNRs. After 4 weeks of implantation, we observed two distinctive issues regarding long-term implantation, each caused by chronic tissue responses or by the delamination of insulation layer. The results demonstrate that the FPMAs successfully recorded neuronal signals up to 12 weeks, with very stably maintained SNRs, reduced by only 16.1% on average compared to the first recordings, although biological tissue reactions or physical degradation of the FPMA were present.Significance. The fabricated FPMAs successfully recorded intracortical signals for 3 months. The SNR was maintained up to 3 months and the chronic function of FPMA was comparable with other silicon based implantable electrodes.
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Affiliation(s)
- Jae-Won Jang
- Department of Robotics Engineering, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, Republic of Korea
| | - Yoo Na Kang
- Department of Medical Assistant Robot, Korea Institute of Machinery and Materials (KIMM), Daegu, Republic of Korea
| | - Hee Won Seo
- Department of Robotics Engineering, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, Republic of Korea
| | - Boil Kim
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, Republic of Korea
| | - Han Kyoung Choe
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, Republic of Korea
| | - Sang Hyun Park
- Department of Robotics Engineering, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, Republic of Korea
| | - Maan-Gee Lee
- Department of Pharmacology, School of MedicineKyungpook National University, Daegu, Republic of Korea.,Brain Science and Engineering Institute, Kyungpook National University, Daegu, Republic of Korea
| | - Sohee Kim
- Department of Robotics Engineering, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, Republic of Korea
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Seaton BT, Heien ML. Biocompatible reference electrodes to enhance chronic electrochemical signal fidelity in vivo. Anal Bioanal Chem 2021; 413:6689-6701. [PMID: 34595560 DOI: 10.1007/s00216-021-03640-w] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Revised: 08/27/2021] [Accepted: 08/30/2021] [Indexed: 12/17/2022]
Abstract
In vivo electrochemistry is a vital tool of neuroscience that allows for the detection, identification, and quantification of neurotransmitters, their metabolites, and other important analytes. One important goal of in vivo electrochemistry is a better understanding of progressive neurological disorders (e.g., Parkinson's disease). A complete understanding of such disorders can only be achieved through a combination of acute (i.e., minutes to hours) and chronic (i.e., days or longer) experimentation. Chronic studies are more challenging because they require prolonged implantation of electrodes, which elicits an immune response, leading to glial encapsulation of the electrodes and altered electrode performance (i.e., biofouling). Biofouling leads to increased electrode impedance and reference electrode polarization, both of which diminish the selectivity and sensitivity of in vivo electrochemical measurements. The increased impedance factor has been successfully mitigated previously with the use of a counter electrode, but the challenge of reference electrode polarization remains. The commonly used Ag/AgCl reference electrode lacks the long-term potential stability in vivo required for chronic measurements. In addition, the cytotoxicity of Ag/AgCl adversely affects animal experimentation and prohibits implantation in humans, hindering translational research progress. Thus, a move toward biocompatible reference electrodes with superior chronic potential stability is necessary. Two qualifying materials, iridium oxide and boron-doped diamond, are introduced and discussed in terms of their electrochemical properties, biocompatibilities, fabrication methods, and applications. In vivo electrochemistry continues to advance toward more chronic experimentation in both animal models and humans, necessitating the utilization of biocompatible reference electrodes that should provide superior potential stability and allow for unprecedented chronic signal fidelity when used with a counter electrode for impedance mitigation.
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Affiliation(s)
- Blake T Seaton
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ, 85721, USA
| | - Michael L Heien
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ, 85721, USA.
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Long-term in vivo two-photon imaging of the neuroinflammatory response to intracortical implants and micro-vessel disruptions in awake mice. Biomaterials 2021; 276:121060. [PMID: 34419839 DOI: 10.1016/j.biomaterials.2021.121060] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2021] [Revised: 07/16/2021] [Accepted: 08/04/2021] [Indexed: 12/17/2022]
Abstract
Our understanding of biomaterials in the brain have been greatly enhanced by advancements in in vivo imaging technologies such as two-photon microscopy. However, when applied to chronic studies, two-photon microscopy enables high-resolution imaging only in superficial regions due to inflammatory responses introduced by the craniotomy and insertion of foreign biomaterials. Microprisms provide a unique vertical view from brain surface to ~1 mm deep or more (depending on the size of the microprisms) which may break through this limitation on imaging depth. Although microprism has been used in the field of neuroscience, the in vivo foreign body responses to the microprism implant have yet to be fully elucidated. This is of important concern in broader applications of this approach, especially for neuroinflammation-sensitive studies. In this work, we first assessed the activation of microglia/macrophages for 16 weeks after microprism implantation using two-photon microscopy in awake CX3CR1-GFP mice. The imaging window became clear from bleedings after ~2 weeks and the maximum imaging distance (in the horizontal direction) stabilized at around 500 μm after ~5 weeks. We also quantified the microglial morphology from week 3 to week 16 post-implantation. Compared to non-implant controls, microglia near the microprism showed higher cell density, smaller soma, and shorter and less branched processes in the early-chronic phase. After week 5, microglial morphology further than 100 μm from the microprism was generally similar to microglia in the control group. In addition, time-lapse imaging confirmed that microglial processes were surveying normally from week 3, even for microglia as close as 50 μm away. These morphological analyses and dynamic imaging results suggest that microglia around chronically implanted microprism eventually exhibit inactive phenotypes. Next, we examined microglial/macrophage responses following laser induced micro-vessel disruptions as an example application of microprism implantation for neuroinflammation related studies. Through the microprism, we captured microglial/macrophage polarization and migration, as well as blood flow changes after the insult for additional 16 weeks. To our surprise, microglia/macrophage aggregation around the insult site was sustained over the 16-week observation period. This work demonstrates the feasibility of using microprisms for long-term characterizations of inflammatory responses to other injuries including implantable devices at deeper depths than that achievable by conventional two-photon microscopy.
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Lee Y, Shin H, Lee D, Choi S, Cho I, Seo J. A Lubricated Nonimmunogenic Neural Probe for Acute Insertion Trauma Minimization and Long-Term Signal Recording. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2021; 8:e2100231. [PMID: 34085402 PMCID: PMC8336494 DOI: 10.1002/advs.202100231] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Revised: 03/29/2021] [Indexed: 05/06/2023]
Abstract
Brain-machine interfaces (BMIs) that link the brain to a machine are promising for the treatment of neurological disorders through the bi-directional translation of neural information over extended periods. However, the longevity of such implanted devices remains limited by the deterioration of their signal sensitivity over time due to acute inflammation from insertion trauma and chronic inflammation caused by the foreign body reaction. To address this challenge, a lubricated surface is fabricated to minimize friction during insertion and avoid immunogenicity during neural signal recording. Reduced friction force leads to 86% less impulse on the brain tissue, and thus immediately increases the number of measured signal electrodes by 102% upon insertion. Furthermore, the signal measurable period increases from 8 to 16 weeks due to the prevention of gliosis. By significantly reducing insertion damage and the foreign body reaction, the lubricated immune-stealthy probe surface (LIPS) can maximize the longevity of implantable BMIs.
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Affiliation(s)
- Yeontaek Lee
- School of Electrical and Electronic EngineeringYonsei UniversitySeoul03722Republic of Korea
| | - Hyogeun Shin
- Center for BioMicrosystemsBrain Science InstituteKorea Institute of Science and Technology (KIST)Seoul02792Republic of Korea
- Division of Bio‐Medical Science & Technology, KIST SchoolKorea University of Science and Technology (UST)Seoul02792Republic of Korea
| | - Dongwon Lee
- School of Electrical and Electronic EngineeringYonsei UniversitySeoul03722Republic of Korea
| | - Sungah Choi
- School of Electrical and Electronic EngineeringYonsei UniversitySeoul03722Republic of Korea
| | - Il‐Joo Cho
- School of Electrical and Electronic EngineeringYonsei UniversitySeoul03722Republic of Korea
- Center for BioMicrosystemsBrain Science InstituteKorea Institute of Science and Technology (KIST)Seoul02792Republic of Korea
- Division of Bio‐Medical Science & Technology, KIST SchoolKorea University of Science and Technology (UST)Seoul02792Republic of Korea
- Yonsei‐KIST Convergence Research InstituteYonsei UniversitySeoul03722Republic of Korea
| | - Jungmok Seo
- School of Electrical and Electronic EngineeringYonsei UniversitySeoul03722Republic of Korea
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Szymanski LJ, Kellis S, Liu CY, Jones KT, Andersen RA, Commins D, Lee B, McCreery DB, Miller CA. Neuropathological effects of chronically implanted, intracortical microelectrodes in a tetraplegic patient. J Neural Eng 2021; 18. [PMID: 34314384 DOI: 10.1088/1741-2552/ac127e] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Accepted: 07/08/2021] [Indexed: 11/12/2022]
Abstract
Objective.Intracortical microelectrode arrays (MEA) can be used as part of a brain-machine interface system to provide sensory feedback control of an artificial limb to assist persons with tetraplegia. Variability in functionality of electrodes has been reported but few studies in humans have examined the impact of chronic brain tissue responses revealed postmortem on electrode performancein vivo. Approach.In a tetraplegic man, recording MEAs were implanted into the anterior intraparietal area and Brodmann's area 5 (BA5) of the posterior parietal cortex and a recording and stimulation array was implanted in BA1 of the primary somatosensory cortex (S1). The participant expired from unrelated causes seven months after MEA implantation. The underlying tissue of two of the three devices was processed for histology and electrophysiological recordings were assessed.Main results.Recordings of neuronal activity were obtained from all three MEAs despite meningeal encapsulation. However, the S1 array had a greater encapsulation, yielded lower signal quality than the other arrays and failed to elicit somatosensory percepts with electrical stimulation. Histological examination of tissues underlying S1 and BA5 implant sites revealed localized leptomeningeal proliferation and fibrosis, lymphocytic infiltrates, astrogliosis, and foreign body reaction around the electrodes. The BA5 recording site showed focal cerebral microhemorrhages and leptomeningeal vascular ectasia. The S1 site showed focal tissue damage including vascular recanalization, neuronal loss, and extensive subcortical white matter necrosis. The tissue response at the S1 site included hemorrhagic-induced injury suggesting a likely mechanism for reduced function of the S1 implant.Significance.Our findings are similar to those from animal studies with chronic intracortical implants and suggest that vascular disruption and microhemorrhage during device implantation are important contributors to overall array and individual electrode performance and should be a topic for future device development to mitigate tissue responses. Neurosurgical considerations are also discussed.
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Affiliation(s)
- Linda J Szymanski
- Department of Pathology, Keck USC School of Medicine, Los Angeles, CA, United States of America.,Department of Pathology and Laboratory Medicine, Children's Hospital of Los Angeles, Los Angeles, CA, United States of America
| | - Spencer Kellis
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, United States of America.,Tianqiao and Chrissy Chen Brain-Machine Interface Center, Chen Institute for Neuroscience, California Institute of Technology, Pasadena, CA, United States of America.,Department of Neurosurgery, Keck USC School of Medicine, Los Angeles, CA, United States of America.,USC Neurorestoration Center, Keck USC School of Medicine, Los Angeles, CA, United States of America
| | - Charles Y Liu
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, United States of America.,Department of Neurosurgery, Keck USC School of Medicine, Los Angeles, CA, United States of America.,USC Neurorestoration Center, Keck USC School of Medicine, Los Angeles, CA, United States of America
| | - Kymry T Jones
- Department of Pathology, Keck USC School of Medicine, Los Angeles, CA, United States of America
| | - Richard A Andersen
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, United States of America.,Tianqiao and Chrissy Chen Brain-Machine Interface Center, Chen Institute for Neuroscience, California Institute of Technology, Pasadena, CA, United States of America
| | - Deborah Commins
- Department of Pathology, Keck USC School of Medicine, Los Angeles, CA, United States of America
| | - Brian Lee
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, United States of America.,Department of Neurosurgery, Keck USC School of Medicine, Los Angeles, CA, United States of America.,USC Neurorestoration Center, Keck USC School of Medicine, Los Angeles, CA, United States of America
| | - Douglas B McCreery
- Huntington Medical Research Institute, Pasadena, CA, United States of America
| | - Carol A Miller
- Department of Pathology, Keck USC School of Medicine, Los Angeles, CA, United States of America
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Abstract
Flexible bioelectronics have promising applications in electronic skin, wearable devices, biomedical electronics, etc. Hydrogels have unique advantages for bioelectronics due to their tissue-like mechanical properties and excellent biocompatibility. Particularly, conductive and tissue adhesive hydrogels can self-adhere to bio-tissues and have great potential in implantable wearable bioelectronics. This review focuses on the recent progress in tissue adhesive hydrogel bioelectronics, including the mechanism and preparation of tissue adhesive hydrogels, the fabrication strategies of conductive hydrogels, and tissue adhesive hydrogel bioelectronics and applications. Some perspectives on tissue adhesive hydrogel bioelectronics are provided at the end of the review.
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Affiliation(s)
- Shengnan Li
- Key Laboratory of Polymeric Composite and Functional Materials of Ministry of Education, Guangdong Functional Biomaterials Engineering Technology Research Center, Guangzhou Key Laboratory of Flexible Electronic Materials and Wearable Devices, School of Materials Science and Engineering, Sun Yat-sen University, 135 Xingang Road West, Guangzhou 510275, China.
| | - Yang Cong
- College of Materials Science and Chemical Engineering, Ningbo University of Technology, Ningbo 315201, China
| | - Jun Fu
- Key Laboratory of Polymeric Composite and Functional Materials of Ministry of Education, Guangdong Functional Biomaterials Engineering Technology Research Center, Guangzhou Key Laboratory of Flexible Electronic Materials and Wearable Devices, School of Materials Science and Engineering, Sun Yat-sen University, 135 Xingang Road West, Guangzhou 510275, China.
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44
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Sugashi T, Yuki H, Niizawa T, Takuwa H, Kanno I, Masamoto K. Three-dimensional microvascular network reconstruction from in vivo images with adaptation of the regional inhomogeneity in the signal-to-noise ratio. Microcirculation 2021; 28:e12697. [PMID: 33786951 DOI: 10.1111/micc.12697] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 02/19/2021] [Accepted: 03/22/2021] [Indexed: 11/27/2022]
Abstract
OBJECTIVE Quantification of angiographic images with two-photon laser scanning fluorescence microscopy (2PLSM) relies on proper segmentation of the vascular images. However, the images contain inhomogeneities in the signal-to-noise ratio (SNR) arising from regional effects of light scattering and absorption. The present study developed a semiautomated quantification method for volume images of 2PLSM angiography by adjusting the binarization threshold according to local SNR along the vessel centerlines. METHODS A phantom model made with fluorescent microbeads was used to incorporate a region-dependent binarization threshold. RESULTS The recommended SNR for imaging was found to be 4.2-10.6 that provide the true size of imaged objects if the binarization threshold was fixed at 50% of SNR. However, angiographic images in the mouse cortex showed variable SNR up to 45 over the depths. To minimize the errors caused by variable SNR and a spatial extent of the imaged objects in an axial direction, the microvascular networks were three-dimensionally reconstructed based on the cross-sectional diameters measured along the vessel centerline from the XY-plane images with adapted binarization threshold. The arterial volume was relatively constant over depths of 0-500 µm, and the capillary volume (1.7% relative to the scanned volume) showed the larger volumes than the artery (0.8%) and vein (0.6%). CONCLUSIONS The present methods allow consistent segmentation of microvasculature by adapting the local inhomogeneity in the SNR, which will be useful for quantitative comparison of the microvascular networks, such as under disease conditions where SNR in the 2PLSM images varies over space and time.
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Affiliation(s)
- Takuma Sugashi
- Department of Mechanical Engineering and Intelligent Systems, Graduate School of Informatics and Engineering, University of Electro-Communications, Chofu, Japan
| | - Hiroya Yuki
- Department of Mechanical Engineering and Intelligent Systems, Graduate School of Informatics and Engineering, University of Electro-Communications, Chofu, Japan
| | - Tomoya Niizawa
- Department of Mechanical Engineering and Intelligent Systems, Graduate School of Informatics and Engineering, University of Electro-Communications, Chofu, Japan
| | - Hiroyuki Takuwa
- Functional Brain Imaging Research, National Institute of Radiological Sciences, Chiba, Japan
| | - Iwao Kanno
- Functional Brain Imaging Research, National Institute of Radiological Sciences, Chiba, Japan
| | - Kazuto Masamoto
- Department of Mechanical Engineering and Intelligent Systems, Graduate School of Informatics and Engineering, University of Electro-Communications, Chofu, Japan.,Functional Brain Imaging Research, National Institute of Radiological Sciences, Chiba, Japan.,Center for Neuroscience and Biomedical Engineering, University of Electro-Communications, Chofu, Japan
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McGlynn E, Nabaei V, Ren E, Galeote‐Checa G, Das R, Curia G, Heidari H. The Future of Neuroscience: Flexible and Wireless Implantable Neural Electronics. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2021; 8:2002693. [PMID: 34026431 PMCID: PMC8132070 DOI: 10.1002/advs.202002693] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Revised: 01/15/2021] [Indexed: 05/04/2023]
Abstract
Neurological diseases are a prevalent cause of global mortality and are of growing concern when considering an ageing global population. Traditional treatments are accompanied by serious side effects including repeated treatment sessions, invasive surgeries, or infections. For example, in the case of deep brain stimulation, large, stiff, and battery powered neural probes recruit thousands of neurons with each pulse, and can invoke a vigorous immune response. This paper presents challenges in engineering and neuroscience in developing miniaturized and biointegrated alternatives, in the form of microelectrode probes. Progress in design and topology of neural implants has shifted the goal post toward highly specific recording and stimulation, targeting small groups of neurons and reducing the foreign body response with biomimetic design principles. Implantable device design recommendations, fabrication techniques, and clinical evaluation of the impact flexible, integrated probes will have on the treatment of neurological disorders are provided in this report. The choice of biocompatible material dictates fabrication techniques as novel methods reduce the complexity of manufacture. Wireless power, the final hurdle to truly implantable neural interfaces, is discussed. These aspects are the driving force behind continued research: significant breakthroughs in any one of these areas will revolutionize the treatment of neurological disorders.
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Affiliation(s)
- Eve McGlynn
- Microelectronics LabJames Watt School of EngineeringUniversity of GlasgowGlasgowG12 8QQUnited Kingdom
| | - Vahid Nabaei
- Microelectronics LabJames Watt School of EngineeringUniversity of GlasgowGlasgowG12 8QQUnited Kingdom
| | - Elisa Ren
- Laboratory of Experimental Electroencephalography and NeurophysiologyDepartment of BiomedicalMetabolic and Neural SciencesUniversity of Modena and Reggio EmiliaModena41125Italy
| | - Gabriel Galeote‐Checa
- Microelectronics LabJames Watt School of EngineeringUniversity of GlasgowGlasgowG12 8QQUnited Kingdom
| | - Rupam Das
- Microelectronics LabJames Watt School of EngineeringUniversity of GlasgowGlasgowG12 8QQUnited Kingdom
| | - Giulia Curia
- Laboratory of Experimental Electroencephalography and NeurophysiologyDepartment of BiomedicalMetabolic and Neural SciencesUniversity of Modena and Reggio EmiliaModena41125Italy
| | - Hadi Heidari
- Microelectronics LabJames Watt School of EngineeringUniversity of GlasgowGlasgowG12 8QQUnited Kingdom
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Thielen B, Meng E. A comparison of insertion methods for surgical placement of penetrating neural interfaces. J Neural Eng 2021; 18:10.1088/1741-2552/abf6f2. [PMID: 33845469 PMCID: PMC8600966 DOI: 10.1088/1741-2552/abf6f2] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Accepted: 04/12/2021] [Indexed: 02/07/2023]
Abstract
Many implantable electrode arrays exist for the purpose of stimulating or recording electrical activity in brain, spinal, or peripheral nerve tissue, however most of these devices are constructed from materials that are mechanically rigid. A growing body of evidence suggests that the chronic presence of these rigid probes in the neural tissue causes a significant immune response and glial encapsulation of the probes, which in turn leads to gradual increase in distance between the electrodes and surrounding neurons. In recording electrodes, the consequence is the loss of signal quality and, therefore, the inability to collect electrophysiological recordings long term. In stimulation electrodes, higher current injection is required to achieve a comparable response which can lead to tissue and electrode damage. To minimize the impact of the immune response, flexible neural probes constructed with softer materials have been developed. These flexible probes, however, are often not strong enough to be inserted on their own into the tissue, and instead fail via mechanical buckling of the shank under the force of insertion. Several strategies have been developed to allow the insertion of flexible probes while minimizing tissue damage. It is critical to keep these strategies in mind during probe design in order to ensure successful surgical placement. In this review, existing insertion strategies will be presented and evaluated with respect to surgical difficulty, immune response, ability to reach the target tissue, and overall limitations of the technique. Overall, the majority of these insertion techniques have only been evaluated for the insertion of a single probe and do not quantify the accuracy of probe placement. More work needs to be performed to evaluate and optimize insertion methods for accurate placement of devices and for devices with multiple probes.
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Affiliation(s)
- Brianna Thielen
- Department of Biomedical Engineering, University of Southern California, Los Angeles, CA, United States of America
| | - Ellis Meng
- Department of Biomedical Engineering, University of Southern California, Los Angeles, CA, United States of America
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47
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Dubaniewicz M, Eles JR, Lam S, Song S, Cambi F, Sun D, Wellman SM, Kozai TDY. Inhibition of Na +/H +exchanger modulates microglial activation and scar formation following microelectrode implantation. J Neural Eng 2021; 18. [PMID: 33621208 DOI: 10.1088/1741-2552/abe8f1] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Accepted: 02/23/2021] [Indexed: 11/12/2022]
Abstract
Objective.Intracortical microelectrodes are an important tool for neuroscience research and have great potential for clinical use. However, the use of microelectrode arrays to treat neurological disorders and control prosthetics is limited by biological challenges such as glial scarring, which can impair chronic recording performance. Microglia activation is an early and prominent contributor to glial scarring. After insertion of an intracortical microelectrode, nearby microglia transition into a state of activation, migrate, and encapsulate the device. Na+/H+exchanger isoform-1 (NHE-1) is involved in various microglial functions, including their polarity and motility, and has been implicated in pro-inflammatory responses to tissue injury. HOE-642 (cariporide) is an inhibitor of NHE-1 and has been shown to depress microglial activation and inflammatory response in brain injury models.Approach.In this study, the effects of HOE-642 treatment on microglial interactions to intracortical microelectrodes was evaluated using two-photon microscopyin vivo.Main results.The rate at which microglia processes and soma migrate in response to electrode implantation was unaffected by HOE-642 administration. However, HOE-642 administration effectively reduced the radius of microglia activation at 72 h post-implantation from 222.2µm to 177.9µm. Furthermore, treatment with HOE-642 significantly reduced microglial encapsulation of implanted devices at 5 h post-insertion from 50.7 ± 6.0% to 8.9 ± 6.1%, which suggests an NHE-1-specific mechanism mediating microglia reactivity and gliosis during implantation injury.Significance.This study implicates NHE-1 as a potential target of interest in microglial reactivity and HOE-642 as a potential treatment to attenuate the glial response and scar formation around implanted intracortical microelectrodes.
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Affiliation(s)
- Mitchell Dubaniewicz
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, United States of America
| | - James R Eles
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, United States of America.,Center for Neural Basis of Cognition, Pittsburgh, PA, United States of America
| | - Stephanie Lam
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, United States of America.,Center for Neural Basis of Cognition, Pittsburgh, PA, United States of America
| | - Shanshan Song
- Department of Neurology, University of Pittsburgh, Pittsburgh, PA, United States of America
| | - Franca Cambi
- Veterans Administration Pittsburgh, Pittsburgh, PA, United States of America.,Department of Neurology, University of Pittsburgh, Pittsburgh, PA, United States of America
| | - Dandan Sun
- Veterans Administration Pittsburgh, Pittsburgh, PA, United States of America.,Department of Neurology, University of Pittsburgh, Pittsburgh, PA, United States of America
| | - Steven M Wellman
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, United States of America.,Center for Neural Basis of Cognition, Pittsburgh, PA, United States of America
| | - Takashi D Y Kozai
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, United States of America.,Center for Neural Basis of Cognition, Pittsburgh, PA, United States of America.,Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA, United States of America.,McGowan Institute of Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA, United States of America.,NeuroTech Center, University of Pittsburgh Brain Institute, Pittsburgh, PA, United States of America
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48
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Sperry ZJ, Na K, Jun J, Madden LR, Socha A, Yoon E, Seymour JP, Bruns TM. High-density neural recordings from feline sacral dorsal root ganglia with thin-film array. J Neural Eng 2021; 18. [PMID: 33545709 DOI: 10.1088/1741-2552/abe398] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Accepted: 02/05/2021] [Indexed: 12/26/2022]
Abstract
Objective. Dorsal root ganglia (DRG) are promising sites for recording sensory activity. Current technologies for DRG recording are stiff and typically do not have sufficient site density for high-fidelity neural data techniques.Approach. In acute experiments, we demonstrate single-unit neural recordings in sacral DRG of anesthetized felines using a 4.5µm thick, high-density flexible polyimide microelectrode array with 60 sites and 30-40µm site spacing. We delivered arrays into DRG with ultrananocrystalline diamond shuttles designed for high stiffness affording a smaller footprint. We recorded neural activity during sensory activation, including cutaneous brushing and bladder filling, as well as during electrical stimulation of the pudendal nerve and anal sphincter. We used specialized neural signal analysis software to sort densely packed neural signals.Main results. We successfully delivered arrays in five of six experiments and recorded single-unit sensory activity in four experiments. The median neural signal amplitude was 55μV peak-to-peak and the maximum unique units recorded at one array position was 260, with 157 driven by sensory or electrical stimulation. In one experiment, we used the neural analysis software to track eight sorted single units as the array was retracted ∼500μm.Significance. This study is the first demonstration of ultrathin, flexible, high-density electronics delivered into DRG, with capabilities for recording and tracking sensory information that are a significant improvement over conventional DRG interfaces.
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Affiliation(s)
- Zachariah J Sperry
- Biomedical Engineering, University of Michigan, Ann Arbor, MI, United States of America.,Biointerfaces Institute, University of Michigan, Ann Arbor, MI, United States of America
| | - Kyounghwan Na
- Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, MI, United States of America
| | - James Jun
- Flatiron Institute, Simons Foundation, New York City, NY, United States of America
| | - Lauren R Madden
- Biomedical Engineering, University of Michigan, Ann Arbor, MI, United States of America.,Biointerfaces Institute, University of Michigan, Ann Arbor, MI, United States of America
| | - Alec Socha
- Biointerfaces Institute, University of Michigan, Ann Arbor, MI, United States of America.,Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, MI, United States of America
| | - Eusik Yoon
- Biomedical Engineering, University of Michigan, Ann Arbor, MI, United States of America.,Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, MI, United States of America.,Center for Nanomedicine, Institute for Basic Science (IBS) and Graduate Program of Nano Biomedical Engineering (NanoBME), Advanced Science Institute, Yonsei University, Seoul, Republic of Korea
| | - John P Seymour
- Biomedical Engineering, University of Michigan, Ann Arbor, MI, United States of America.,Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, MI, United States of America.,University of Texas Health Science Center, Department of Neurosurgery, Houston, TX, United States of America.,Department of Electrical and Computer Engineering, Rice University, Houston, TX, United States of America
| | - Tim M Bruns
- Biomedical Engineering, University of Michigan, Ann Arbor, MI, United States of America.,Biointerfaces Institute, University of Michigan, Ann Arbor, MI, United States of America
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Sahasrabuddhe K, Khan AA, Singh AP, Stern TM, Ng Y, Tadić A, Orel P, LaReau C, Pouzzner D, Nishimura K, Boergens KM, Shivakumar S, Hopper MS, Kerr B, Hanna MES, Edgington RJ, McNamara I, Fell D, Gao P, Babaie-Fishani A, Veijalainen S, Klekachev AV, Stuckey AM, Luyssaert B, Kozai TDY, Xie C, Gilja V, Dierickx B, Kong Y, Straka M, Sohal HS, Angle MR. The Argo: a high channel count recording system for neural recording in vivo. J Neural Eng 2021; 18:015002. [PMID: 33624614 PMCID: PMC8607496 DOI: 10.1088/1741-2552/abd0ce] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
OBJECTIVE Decoding neural activity has been limited by the lack of tools available to record from large numbers of neurons across multiple cortical regions simultaneously with high temporal fidelity. To this end, we developed the Argo system to record cortical neural activity at high data rates. APPROACH Here we demonstrate a massively parallel neural recording system based on platinum-iridium microwire electrode arrays bonded to a CMOS voltage amplifier array. The Argo system is the highest channel count in vivo neural recording system, supporting simultaneous recording from 65 536 channels, sampled at 32 kHz and 12-bit resolution. This system was designed for cortical recordings, compatible with both penetrating and surface microelectrodes. MAIN RESULTS We validated this system through initial bench testing to determine specific gain and noise characteristics of bonded microwires, followed by in-vivo experiments in both rat and sheep cortex. We recorded spiking activity from 791 neurons in rats and surface local field potential activity from over 30 000 channels in sheep. SIGNIFICANCE These are the largest channel count microwire-based recordings in both rat and sheep. While currently adapted for head-fixed recording, the microwire-CMOS architecture is well suited for clinical translation. Thus, this demonstration helps pave the way for a future high data rate intracortical implant.
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Affiliation(s)
| | - Aamir A Khan
- Paradromics, Inc, Austin, TX, United States of America
| | | | - Tyler M Stern
- Paradromics, Inc, Austin, TX, United States of America
| | - Yeena Ng
- Paradromics, Inc, Austin, TX, United States of America
| | | | - Peter Orel
- Paradromics, Inc, Austin, TX, United States of America
| | - Chris LaReau
- Paradromics, Inc, Austin, TX, United States of America
| | | | | | | | | | | | - Bryan Kerr
- Paradromics, Inc, Austin, TX, United States of America
| | | | | | | | - Devin Fell
- Paradromics, Inc, Austin, TX, United States of America
| | - Peng Gao
- Caeleste CVBA, Mechelen, Belgium
| | | | | | | | | | | | - Takashi D Y Kozai
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, United States of America
- Center for the Neural Basis of Cognition, University of Pittsburgh, Pittsburgh, PA, United States of America
- McGowan Institute of Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA, United States of America
- Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA, United States of America
- NeuroTech Center, University of Pittsburgh Brain Institute, Pittsburgh, PA, United States of America
| | - Chong Xie
- Department of Electrical and Computer Engineering, Rice University, Houston, TX, United States of America
- Department of Bioengineering, Rice University, Houston, TX, United States of America
- NeuroEngineering Initiative, Rice University, Houston, TX, United States of America
| | - Vikash Gilja
- Department of Electrical and Computer Engineering, University of California, San Diego, La Jolla, CA, United States of America
| | | | - Yifan Kong
- Paradromics, Inc, Austin, TX, United States of America
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Bennett C, Álvarez-Ciara A, Franklin M, Dietrich WD, Prasad A. The complement cascade at the Utah microelectrode-tissue interface. Biomaterials 2021; 268:120583. [PMID: 33310540 PMCID: PMC7856077 DOI: 10.1016/j.biomaterials.2020.120583] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Revised: 11/16/2020] [Accepted: 11/25/2020] [Indexed: 01/05/2023]
Abstract
Devices implanted within the central nervous system (CNS) are subjected to tissue reactivity due to the lack of biocompatibility between implanted material and the cells' microenvironment. Studies have attributed blood-brain barrier disruption, inflammation, and oxidative stress as main contributing factors that lead to electrode recording failure. The complement cascade is a part of the innate immunity that focuses on recognizing and targeting foreign objects; however, its role in the context of neural implants is substantially unknown. In this study, we implanted a non-functional 4x4 Utah microelectrode array (UEA) into the somatosensory cortex and studied the complement cascade via combined gene and immunohistochemistry quantification at acute (48-h), sub-acute (1-week), and early chronic (4-weeks) time points. The results of this study demonstrate the activation and continuation of the complement cascade at the electrode-tissue interface, illustrating the therapeutic potential of modulating the foreign body response via the complement cascade.
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Affiliation(s)
- Cassie Bennett
- Department of Biomedical Engineering, University of Miami, FL, USA
| | | | - Melissa Franklin
- Department of Biomedical Engineering, University of Miami, FL, USA
| | | | - Abhishek Prasad
- Department of Biomedical Engineering, University of Miami, FL, USA; The Miami Project to Cure Paralysis, University of Miami, FL, USA.
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