1
|
Xu F, Jin H, Liu L, Yang Y, Cen J, Wu Y, Chen S, Sun D. Architecture design and advanced manufacturing of heart-on-a-chip: scaffolds, stimulation and sensors. MICROSYSTEMS & NANOENGINEERING 2024; 10:96. [PMID: 39006908 PMCID: PMC11239895 DOI: 10.1038/s41378-024-00692-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Revised: 02/18/2024] [Accepted: 02/28/2024] [Indexed: 07/16/2024]
Abstract
Heart-on-a-chip (HoC) has emerged as a highly efficient, cost-effective device for the development of engineered cardiac tissue, facilitating high-throughput testing in drug development and clinical treatment. HoC is primarily used to create a biomimetic microphysiological environment conducive to fostering the maturation of cardiac tissue and to gather information regarding the real-time condition of cardiac tissue. The development of architectural design and advanced manufacturing for these "3S" components, scaffolds, stimulation, and sensors is essential for improving the maturity of cardiac tissue cultivated on-chip, as well as the precision and accuracy of tissue states. In this review, the typical structures and manufacturing technologies of the "3S" components are summarized. The design and manufacturing suggestions for each component are proposed. Furthermore, key challenges and future perspectives of HoC platforms with integrated "3S" components are discussed. Architecture design concepts of scaffolds, stimulation and sensors in chips.
Collapse
Affiliation(s)
- Feng Xu
- Pen-Tung Sah Institute of Micro-Nano Science and Technology, Xiamen University, Xiamen, 361102 China
| | - Hang Jin
- Pen-Tung Sah Institute of Micro-Nano Science and Technology, Xiamen University, Xiamen, 361102 China
| | - Lingling Liu
- Pen-Tung Sah Institute of Micro-Nano Science and Technology, Xiamen University, Xiamen, 361102 China
| | - Yuanyuan Yang
- Pen-Tung Sah Institute of Micro-Nano Science and Technology, Xiamen University, Xiamen, 361102 China
| | - Jianzheng Cen
- Guangdong Provincial People’s Hospital, Guangzhou, 510080 China
| | - Yaobin Wu
- School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515 China
| | - Songyue Chen
- Pen-Tung Sah Institute of Micro-Nano Science and Technology, Xiamen University, Xiamen, 361102 China
| | - Daoheng Sun
- Pen-Tung Sah Institute of Micro-Nano Science and Technology, Xiamen University, Xiamen, 361102 China
| |
Collapse
|
2
|
Liu X, Gong Y, Jiang Z, Stevens T, Li W. Flexible high-density microelectrode arrays for closed-loop brain-machine interfaces: a review. Front Neurosci 2024; 18:1348434. [PMID: 38686330 PMCID: PMC11057246 DOI: 10.3389/fnins.2024.1348434] [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: 12/02/2023] [Accepted: 01/12/2024] [Indexed: 05/02/2024] Open
Abstract
Flexible high-density microelectrode arrays (HDMEAs) are emerging as a key component in closed-loop brain-machine interfaces (BMIs), providing high-resolution functionality for recording, stimulation, or both. The flexibility of these arrays provides advantages over rigid ones, such as reduced mismatch between interface and tissue, resilience to micromotion, and sustained long-term performance. This review summarizes the recent developments and applications of flexible HDMEAs in closed-loop BMI systems. It delves into the various challenges encountered in the development of ideal flexible HDMEAs for closed-loop BMI systems and highlights the latest methodologies and breakthroughs to address these challenges. These insights could be instrumental in guiding the creation of future generations of flexible HDMEAs, specifically tailored for use in closed-loop BMIs. The review thoroughly explores both the current state and prospects of these advanced arrays, emphasizing their potential in enhancing BMI technology.
Collapse
Affiliation(s)
- Xiang Liu
- Neuroscience Program, Department of Physiology, Michigan State University, East Lansing, MI, United States
- Institute for Quantitative Health Science and Engineering (IQ), East Lansing, MI, United States
| | - Yan Gong
- Institute for Quantitative Health Science and Engineering (IQ), East Lansing, MI, United States
- Department of Electrical and Computer Engineering, Michigan State University, East Lansing, MI, United States
| | - Zebin Jiang
- Institute for Quantitative Health Science and Engineering (IQ), East Lansing, MI, United States
- Department of Electrical and Computer Engineering, Michigan State University, East Lansing, MI, United States
| | - Trevor Stevens
- Department of Electrical and Computer Engineering, Michigan State University, East Lansing, MI, United States
| | - Wen Li
- Neuroscience Program, Department of Physiology, Michigan State University, East Lansing, MI, United States
- Institute for Quantitative Health Science and Engineering (IQ), East Lansing, MI, United States
- Department of Electrical and Computer Engineering, Michigan State University, East Lansing, MI, United States
- Department of Biomedical Engineering, Michigan State University, East Lansing, MI, United States
| |
Collapse
|
3
|
Boltcreed E, Ersöz A, Han M, McConnell GC. Short-Term Effects of Gamma Stimulation on Neuroinflammation at the Tissue-Electrode Interface in Motor Cortex. Neuromodulation 2024; 27:500-508. [PMID: 38099883 PMCID: PMC10990794 DOI: 10.1016/j.neurom.2023.11.003] [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: 08/29/2023] [Revised: 10/20/2023] [Accepted: 11/07/2023] [Indexed: 04/05/2024]
Abstract
OBJECTIVES The reliability of long-term neural recordings as therapeutic interventions for motor and sensory disorders is hampered by the brain tissue response. Previous work showed that flickering light at gamma frequencies (ie, 20-50 Hz) causes enhanced microglial recruitment in the visual cortex. The effects of gamma stimulation on glial cells surrounding implanted neural electrodes are not well understood. We hypothesized that invasive stimulation in the gamma frequency band increases microglial recruitment in the short term and reduces astrogliosis at the tissue-electrode interface. MATERIALS AND METHODS Male Long Evans rats were implanted with dual-shank silicon microelectrode arrays into the motor cortex. After implantation, rats received one hour of 40-Hz stimulation at a constant current of 10 μA using charge-balanced, biphasic pulses on one shank, and the other shank served as the nonstimulated control. Postmortem, tissue sections were stained with ectodermal dysplasia 1 (ED1) for activated microglia, glial fibrillary acidic protein (GFAP) for astrocytes, and 4',6-diamidino-2-phenylindole (DAPI) for nonspecific nuclei. Fluorescent intensity and cell number as a function of distance from the tissue-electrode interface were used to quantify all stained sections. RESULTS Fluorescent intensity for ED1 was nearly 40% lower for control than for stimulated sites (0-500 μm away from the implant), indicating increased microglial recruitment to the stimulated site (p < 0.05). Fluorescent intensity for GFAP was >67% higher for control than for stimulated sites (0-500 μm away from the implant), indicating reduced astrogliosis at the stimulated site (p < 0.05). No differences were observed in DAPI-stained sections between conditions. CONCLUSIONS These results suggest that short-term gamma stimulation modulates glial recruitment in the immediate vicinity of the microelectrode. Future studies will investigate the long-term effects of gamma stimulation on glial recruitment at the tissue-electrode interface as a strategy to improve long-term recording reliability.
Collapse
Affiliation(s)
- Emily Boltcreed
- Stevens Institute of Technology, Hoboken, NJ; Semcer Center for Healthcare Innovation, Hoboken, NJ
| | - Alpaslan Ersöz
- Mechanical Engineering Department, Carnegie Mellon University, Pittsburgh, PA; Department of Biomedical Engineering, University of Connecticut, Storrs, CT
| | - Martin Han
- Department of Biomedical Engineering, University of Connecticut, Storrs, CT
| | - George C McConnell
- Stevens Institute of Technology, Hoboken, NJ; Semcer Center for Healthcare Innovation, Hoboken, NJ.
| |
Collapse
|
4
|
Perna A, Angotzi GN, Berdondini L, Ribeiro JF. Advancing the interfacing performances of chronically implantable neural probes in the era of CMOS neuroelectronics. Front Neurosci 2023; 17:1275908. [PMID: 38027514 PMCID: PMC10644322 DOI: 10.3389/fnins.2023.1275908] [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: 08/10/2023] [Accepted: 10/10/2023] [Indexed: 12/01/2023] Open
Abstract
Tissue penetrating microelectrode neural probes can record electrophysiological brain signals at resolutions down to single neurons, making them invaluable tools for neuroscience research and Brain-Computer-Interfaces (BCIs). The known gradual decrease of their electrical interfacing performances in chronic settings, however, remains a major challenge. A key factor leading to such decay is Foreign Body Reaction (FBR), which is the cascade of biological responses that occurs in the brain in the presence of a tissue damaging artificial device. Interestingly, the recent adoption of Complementary Metal Oxide Semiconductor (CMOS) technology to realize implantable neural probes capable of monitoring hundreds to thousands of neurons simultaneously, may open new opportunities to face the FBR challenge. Indeed, this shift from passive Micro Electro-Mechanical Systems (MEMS) to active CMOS neural probe technologies creates important, yet unexplored, opportunities to tune probe features such as the mechanical properties of the probe, its layout, size, and surface physicochemical properties, to minimize tissue damage and consequently FBR. Here, we will first review relevant literature on FBR to provide a better understanding of the processes and sources underlying this tissue response. Methods to assess FBR will be described, including conventional approaches based on the imaging of biomarkers, and more recent transcriptomics technologies. Then, we will consider emerging opportunities offered by the features of CMOS probes. Finally, we will describe a prototypical neural probe that may meet the needs for advancing clinical BCIs, and we propose axial insertion force as a potential metric to assess the influence of probe features on acute tissue damage and to control the implantation procedure to minimize iatrogenic injury and subsequent FBR.
Collapse
Affiliation(s)
- Alberto Perna
- Microtechnology for Neuroelectronics Lab, Fondazione Istituto Italiano di Tecnologia, Neuroscience and Brain Technologies, Genova, Italy
- The Open University Affiliated Research Centre at Istituto Italiano di Tecnologia (ARC@IIT), Istituto Italiano di Tecnologia, Genova, Italy
| | - Gian Nicola Angotzi
- Microtechnology for Neuroelectronics Lab, Fondazione Istituto Italiano di Tecnologia, Neuroscience and Brain Technologies, Genova, Italy
| | - Luca Berdondini
- Microtechnology for Neuroelectronics Lab, Fondazione Istituto Italiano di Tecnologia, Neuroscience and Brain Technologies, Genova, Italy
| | - João Filipe Ribeiro
- Microtechnology for Neuroelectronics Lab, Fondazione Istituto Italiano di Tecnologia, Neuroscience and Brain Technologies, Genova, Italy
| |
Collapse
|
5
|
Yan T, Suzuki K, Kameda S, Maeda M, Mihara T, Hirata M. Chronic subdural electrocorticography in nonhuman primates by an implantable wireless device for brain-machine interfaces. Front Neurosci 2023; 17:1260675. [PMID: 37841689 PMCID: PMC10568031 DOI: 10.3389/fnins.2023.1260675] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Accepted: 09/12/2023] [Indexed: 10/17/2023] Open
Abstract
Background Subdural electrocorticography (ECoG) signals have been proposed as a stable, good-quality source for brain-machine interfaces (BMIs), with a higher spatial and temporal resolution than electroencephalography (EEG). However, long-term implantation may lead to chronic inflammatory reactions and connective tissue encapsulation, resulting in a decline in signal recording quality. However, no study has reported the effects of the surrounding tissue on signal recording and device functionality thus far. Methods In this study, we implanted a wireless recording device with a customized 32-electrode-ECoG array subdurally in two nonhuman primates for 15 months. We evaluated the neural activities recorded from and wirelessly transmitted to the devices and the chronic tissue reactions around the electrodes. In addition, we measured the gain factor of the newly formed ventral fibrous tissue in vivo. Results Time-frequency analyses of the acute and chronic phases showed similar signal features. The average root mean square voltage and power spectral density showed relatively stable signal quality after chronic implantation. Histological examination revealed thickening of the reactive tissue around the electrode array; however, no evident inflammation in the cortex. From gain factor analysis, we found that tissue proliferation under electrodes reduced the amplitude power of signals. Conclusion This study suggests that subdural ECoG may provide chronic signal recordings for future clinical applications and neuroscience research. This study also highlights the need to reduce proliferation of reactive tissue ventral to the electrodes to enhance long-term stability.
Collapse
Affiliation(s)
- Tianfang Yan
- Department of Neurological Diagnosis and Restoration, Osaka University Graduate School of Medicine, Suita, Japan
| | | | - Seiji Kameda
- Department of Neurological Diagnosis and Restoration, Osaka University Graduate School of Medicine, Suita, Japan
| | - Masashi Maeda
- Candidate Discovery Science Labs, Astellas Pharma Inc., Tokyo, Japan
| | - Takuma Mihara
- Candidate Discovery Science Labs, Astellas Pharma Inc., Tokyo, Japan
| | - Masayuki Hirata
- Department of Neurological Diagnosis and Restoration, Osaka University Graduate School of Medicine, Suita, Japan
- Department of Neurosurgery, Osaka University Graduate School of Medicine, Suita, Japan
- Global Center for Medical Engineering and Informatics, Osaka University, Suita, Japan
| |
Collapse
|
6
|
Trotier A, Bagnoli E, Walski T, Evers J, Pugliese E, Lowery M, Kilcoyne M, Fitzgerald U, Biggs M. Micromotion Derived Fluid Shear Stress Mediates Peri-Electrode Gliosis through Mechanosensitive Ion Channels. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2023; 10:e2301352. [PMID: 37518828 PMCID: PMC10520674 DOI: 10.1002/advs.202301352] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 06/11/2023] [Indexed: 08/01/2023]
Abstract
The development of bioelectronic neural implant technologies has advanced significantly over the past 5 years, particularly in brain-machine interfaces and electronic medicine. However, neuroelectrode-based therapies require invasive neurosurgery and can subject neural tissues to micromotion-induced mechanical shear, leading to chronic inflammation, the formation of a peri-electrode void and the deposition of reactive glial scar tissue. These structures act as physical barriers, hindering electrical signal propagation and reducing neural implant functionality. Although well documented, the mechanisms behind the initiation and progression of these processes are poorly understood. Herein, in silico analysis of micromotion-induced peri-electrode void progression and gliosis is described. Subsequently, ventral mesencephalic cells exposed to milliscale fluid shear stress in vitro exhibited increased expression of gliosis-associated proteins and overexpression of mechanosensitive ion channels PIEZO1 (piezo-type mechanosensitive ion channel component 1) and TRPA1 (transient receptor potential ankyrin 1), effects further confirmed in vivo in a rat model of peri-electrode gliosis. Furthermore, in vitro analysis indicates that chemical inhibition/activation of PIEZO1 affects fluid shear stress mediated astrocyte reactivity in a mitochondrial-dependent manner. Together, the results suggest that mechanosensitive ion channels play a major role in the development of a peri-electrode void and micromotion-induced glial scarring at the peri-electrode region.
Collapse
Affiliation(s)
- Alexandre Trotier
- SFI Research Centre for Medical Devices (CÚRAM)University of GalwayGalwayH91 W2TYIreland
- Galway Neuroscience CentreUniversity of GalwayGalwayH91 W2TYIreland
| | - Enrico Bagnoli
- SFI Research Centre for Medical Devices (CÚRAM)University of GalwayGalwayH91 W2TYIreland
- Galway Neuroscience CentreUniversity of GalwayGalwayH91 W2TYIreland
| | - Tomasz Walski
- SFI Research Centre for Medical Devices (CÚRAM)University of GalwayGalwayH91 W2TYIreland
- Department of Biomedical EngineeringFaculty of Fundamental Problems of TechnologyWrocław University of Science and TechnologyWroclaw50‐370Poland
| | - Judith Evers
- School of Electrical and Electronic EngineeringUniversity College DublinDublin 4Ireland
| | - Eugenia Pugliese
- SFI Research Centre for Medical Devices (CÚRAM)University of GalwayGalwayH91 W2TYIreland
| | - Madeleine Lowery
- School of Electrical and Electronic EngineeringUniversity College DublinDublin 4Ireland
| | - Michelle Kilcoyne
- SFI Research Centre for Medical Devices (CÚRAM)University of GalwayGalwayH91 W2TYIreland
- Galway Neuroscience CentreUniversity of GalwayGalwayH91 W2TYIreland
- Carbohydrate Signalling GroupDiscipline of MicrobiologyUniversity of GalwayGalwayH91 W2TYIreland
| | - Una Fitzgerald
- SFI Research Centre for Medical Devices (CÚRAM)University of GalwayGalwayH91 W2TYIreland
- Galway Neuroscience CentreUniversity of GalwayGalwayH91 W2TYIreland
| | - Manus Biggs
- SFI Research Centre for Medical Devices (CÚRAM)University of GalwayGalwayH91 W2TYIreland
- Galway Neuroscience CentreUniversity of GalwayGalwayH91 W2TYIreland
| |
Collapse
|
7
|
Kumosa LS. Commonly Overlooked Factors in Biocompatibility Studies of Neural Implants. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2023; 10:e2205095. [PMID: 36596702 PMCID: PMC9951391 DOI: 10.1002/advs.202205095] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Revised: 11/16/2022] [Indexed: 06/17/2023]
Abstract
Biocompatibility of cutting-edge neural implants, surgical tools and techniques, and therapeutic technologies is a challenging concept that can be easily misjudged. For example, neural interfaces are routinely gauged on how effectively they determine active neurons near their recording sites. Tissue integration and toxicity of neural interfaces are frequently assessed histologically in animal models to determine tissue morphological and cellular changes in response to surgical implantation and chronic presence. A disconnect between histological and efficacious biocompatibility exists, however, as neuronal numbers frequently observed near electrodes do not match recorded neuronal spiking activity. The downstream effects of the myriad surgical and experimental factors involved in such studies are rarely examined when deciding whether a technology or surgical process is biocompatible. Such surgical factors as anesthesia, temperature excursions, bleed incidence, mechanical forces generated, and metabolic conditions are known to have strong systemic and thus local cellular and extracellular consequences. Many tissue markers are extremely sensitive to the physiological state of cells and tissues, thus significantly impacting histological accuracy. This review aims to shed light on commonly overlooked factors that can have a strong impact on the assessment of neural biocompatibility and to address the mismatch between results stemming from functional and histological methods.
Collapse
Affiliation(s)
- Lucas S. Kumosa
- Neuronano Research CenterDepartment of Experimental Medical ScienceMedical FacultyLund UniversityMedicon Village, Byggnad 404 A2, Scheelevägen 8Lund223 81Sweden
| |
Collapse
|
8
|
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.
Collapse
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.
| |
Collapse
|
9
|
Atkinson EW, Kuliasha CA, Kasper M, Furniturewalla A, Lim AS, Jiracek-Sapieha L, Brake A, Gormaley A, Rivera-Llabres V, Singh I, Spearman B, Rinaldi-Ramos CM, Schmidt CE, Judy JW, Otto KJ. Examining the in vivo functionality of the Magnetically Aligned Regenerative Tissue-Engineered Electronic Nerve Interface (MARTEENI). J Neural Eng 2022; 19. [PMID: 35998559 DOI: 10.1088/1741-2552/ac8bfe] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Accepted: 08/23/2022] [Indexed: 11/11/2022]
Abstract
OBJECTIVE Although neural-enabled prostheses have been used to restore some lost functionality in clinical trials, they have faced difficulty in achieving high degree of freedom, natural use compared to healthy limbs. This study investigated the in vivo functionality of a flexible and scalable regenerative peripheral-nerve interface suspended within a microchannel-embedded, tissue-engineered hydrogel (the Magnetically Aligned Regenerative Tissue-Engineered Electronic Nerve Interface, MARTEENI) as a potential approach to improving current issues in peripheral nerve interfaces. APPROACH Assembled MARTEENI devices were implanted in the gaps of severed sciatic nerves in Lewis rats. Both acute and chronic electrophysiology were recorded, and channel-isolated activity was examined. In terminal experiments, evoked activity during paw compression and stimulus response curves generated from proximal nerve stimulation were examined. Electrochemical impedance spectroscopy was performed to assess the complex impedance of recording sites during chronic data collection. Features of the foreign-body response in non-functional implants were examined using immunohistological methods. MAIN RESULTS Channel-isolated activity was observed in acute, chronic, and terminal experiments and showed a typically biphasic morphology with peak-to-peak amplitudes varying between 50 to 500 µV. For chronic experiments, electrophysiology was observed for 77 days post-implant. Within the templated hydrogel, regenerating axons formed minifascicles that varied in both size and axon count and were also found to surround device threads. No axons were found to penetrate the foreign-body response. Together these results suggest the MARTEENI is a promising approach for interfacing with peripheral nerves. SIGNIFICANCE Findings demonstrate a high likelihood that observed electrophysiological activity recorded from implanted MARTEENIs originated from neural tissue. The variation in minifascicle size seen histologically suggests that amplitude distributions observed in functional MARTEENIs may be due to a combination of individual axon and mini-compound action potentials. This study provided an assessment of a functional MARTEENI in an in vivo animal model for the first time.
Collapse
Affiliation(s)
- Eric W Atkinson
- College of Medicine, University of Florida, 1064 Center Dr., New Engineering Building, Gainesville, 32611-7011, UNITED STATES
| | - Cary A Kuliasha
- Electrical and Computer Engineering, University of Florida, 968 Center Dr., New Engineering Building, Gainesville, Florida, 32611-7011, UNITED STATES
| | - Mary Kasper
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, 1275 Center Drive, P.O. Box 116131, Gainesville, Florida, 32611-7011, UNITED STATES
| | - Abbas Furniturewalla
- Electrical and Computer Engineering, University of Florida, 968 Center Dr., New Engineering Building, Gainesville, Florida, 32611-7011, UNITED STATES
| | - Alexander S Lim
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, 1275 Center Dr., P.O. Box 117200, Gainesville, Florida, 32611-7011, UNITED STATES
| | - Ladan Jiracek-Sapieha
- Electrical and Computer Engineering, University of Florida, 968 Center Dr., Gainesville, Florida, 32611-7011, UNITED STATES
| | - Alexis Brake
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, 1064 Center Dr., New Engineering Building, Gainesville, 32611-7011, UNITED STATES
| | - Anne Gormaley
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, 1064 Center Dr., New Engineering Building, Gainesville, 32611-7011, UNITED STATES
| | - Victor Rivera-Llabres
- Chemistry, University of Florida, P.O. Box 117200, Gainesville, Florida, 32611-7011, UNITED STATES
| | - Ishita Singh
- Chemical Engineering, University of Florida, 1030 Center Drive, Gainesville, Florida, 32611-7011, UNITED STATES
| | - Benjamin Spearman
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, 1064 Center Dr., New Engineering Building, Gainesville, 32611-7011, UNITED STATES
| | - Carlos M Rinaldi-Ramos
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, 1275 Center Dr, Gainesville, Florida, 32610, UNITED STATES
| | - Christine E Schmidt
- Biomedical Engineering Program, University of Florida, P.O. Box 116131, Gainesville , Florida, 32611, UNITED STATES
| | - Jack W Judy
- NIMET, University of Florida Herbert Wertheim College of Engineering, 1041 Center Dr, Gainesville, Florida, 32611-6550, UNITED STATES
| | - Kevin J Otto
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, 1064 Center Dr., Gainesville, Florida, 32611-7011, UNITED STATES
| |
Collapse
|
10
|
Tawakol O, Mushahwar VK, Troyk PR. The Use of Digital Image Correlation for Measurement of Strain Fields in a Novel Wireless Intraspinal Microstimulation Interface. Artif Organs 2022; 46:2066-2072. [PMID: 35747905 DOI: 10.1111/aor.14349] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Revised: 04/13/2022] [Accepted: 06/14/2022] [Indexed: 11/30/2022]
Abstract
BACKGROUND Intraspinal microstimulation (ISMS) has emerged as a promising neuromodulation technique for restoring standing and overground walking in individuals with spinal cord injury. Current and emerging ISMS implant designs connect the electrodes to the stimulator through lead wires that cross the dura mater. To reduce possible complications associated with transdural leads such as tethering and leakage of cerebrospinal fluid, we aim to develop a wireless, fully intradural ISMS implant based upon our prior work in the cortex with the Wireless Floating Microelectrode Array (WFMA). Although we have extensive data about WFMA cortical stability, its mechanical and electrical stability in the spinal cord remain unknown. One of the quantifiable metrics to assess long-term implant stability is mechanical strain. OBJECTIVE The aim of the current work is to develop a method to assess implant stability by measuring strain fields in a surrogate of the human spinal cord. METHODS A physical model of the spinal cord was studied using an electromechanical testing apparatus, simulating typical spinal cord motion. Strain fields were digitally analyzed using an optical method known as digital image correlation (DIC). RESULTS Displacement and strain were visualized using contour plots. The strain values in the vicinity of each WFMA device were significantly different from the strain values in the same locations in the control surrogate spinal cord. CONCLUSION The results demonstrate that DIC can be used for in-vitro screening of intraspinal implants. Accurate optical strain measurements will enable researchers to optimize implant design over a wide range of motion conditions.
Collapse
Affiliation(s)
- Omar Tawakol
- Department of Biomedical Engineering, Illinois Institute of Technology, United States
| | - Vivian K Mushahwar
- Department of Medicine and Neuroscience & Mental Health Institute, University of Alberta, Canada.,Sensory Motor Adaptive Rehabilitation Technology (SMART) Network, University of Alberta, Canada
| | - Philip R Troyk
- Department of Biomedical Engineering, Illinois Institute of Technology, United States.,Sensory Motor Adaptive Rehabilitation Technology (SMART) Network, University of Alberta, Canada
| |
Collapse
|
11
|
Sharafkhani N, Kouzani AZ, Adams SD, Long JM, Lissorgues G, Rousseau L, Orwa JO. Neural tissue-microelectrode interaction: Brain micromotion, electrical impedance, and flexible microelectrode insertion. J Neurosci Methods 2022; 365:109388. [PMID: 34678387 DOI: 10.1016/j.jneumeth.2021.109388] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 10/17/2021] [Accepted: 10/17/2021] [Indexed: 10/20/2022]
Abstract
Insertion of a microelectrode into the brain to record/stimulate neurons damages neural tissue and blood vessels and initiates the brain's wound healing response. Due to the large difference between the stiffness of neural tissue and microelectrode, brain micromotion also leads to neural tissue damage and associated local immune response. Over time, following implantation, the brain's response to the tissue damage can result in microelectrode failure. Reducing the microelectrode's cross-sectional dimensions to single-digit microns or using soft materials with elastic modulus close to that of the neural tissue are effective methods to alleviate the neural tissue damage and enhance microelectrode longevity. However, the increase in electrical impedance of the microelectrode caused by reducing the microelectrode contact site's dimensions can decrease the signal-to-noise ratio. Most importantly, the reduced dimensions also lead to a reduction in the critical buckling force, which increases the microelectrode's propensity to buckling during insertion. After discussing brain micromotion, the main source of neural tissue damage, surface modification of the microelectrode contact site is reviewed as a key method for addressing the increase in electrical impedance issue. The review then focuses on recent approaches to aiding insertion of flexible microelectrodes into the brain, including bending stiffness modification, effective length reduction, and application of a magnetic field to pull the electrode. An understanding of the advantages and drawbacks of the developed strategies offers a guide for dealing with the buckling phenomenon during implantation.
Collapse
Affiliation(s)
- Naser Sharafkhani
- School of Engineering, Deakin University, Geelong, VIC 3216, Australia.
| | - Abbas Z Kouzani
- School of Engineering, Deakin University, Geelong, VIC 3216, Australia
| | - Scott D Adams
- School of Engineering, Deakin University, Geelong, VIC 3216, Australia
| | - John M Long
- School of Engineering, Deakin University, Geelong, VIC 3216, Australia
| | | | | | - Julius O Orwa
- School of Engineering, Deakin University, Geelong, VIC 3216, Australia.
| |
Collapse
|
12
|
Esmaeilzadeh A, Bahmaie N, Nouri E, Hajkazemi MJ, Zareh Rafie M. Immunobiological Properties and Clinical Applications of Interleukin-38 for Immune-Mediated Disorders: A Systematic Review Study. Int J Mol Sci 2021; 22:12552. [PMID: 34830435 PMCID: PMC8625918 DOI: 10.3390/ijms222212552] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 10/18/2021] [Accepted: 10/19/2021] [Indexed: 12/20/2022] Open
Abstract
Exponential growth in the usage of "cytokines" (as seroimmunobiomarkers) has facilitated more accurate prognosis, early diagnosis, novel, and efficient immunotherapeutics. Numerous studies have reported immunopathophysiological and immunopathological processes of interleukin-38 (IL-38). Therefore, in this systematic review article, the authors aimed to present an updated comprehensive overview on the immunobiological mechanisms, diagnostic, and immune gene-based therapeutic potentials of IL-38. According to our inclusion and exclusion criteria, a total of 216 articles were collected from several search engines and databases from the January 2012 to July 2021 time interval by using six main keywords. Physiologic or pathologic microenvironments, optimal dosage, and involved receptors affect the functionalities of IL-38. Alterations in serum levels of IL-38 play a major role in the immunopathogenesis of a wide array of immune-mediated disorders. IL-38 shows anti-inflammatory activities by reduction or inhibition of pro-inflammatory cytokines, supporting the therapeutic aspects of IL-38 in inflammatory autoimmune diseases. According to the importance of pre-clinical studies, it seems that manipulation of the immune system by immunomodulatory properties of IL-38 can increase the accuracy of diagnosis, and decipher optimal clinical outcomes. To promote our knowledge, more collaboration is highly recommended among laboratory scientists, internal/infectious diseases specialists, oncologists, immunologists, diseases-specific biomarkers scientists, and basic medical researchers.
Collapse
Affiliation(s)
- Abdolreza Esmaeilzadeh
- Department of Immunology, School of Medicine, Zanjan University of Medical Sciences, Zanjan 4513956111, Iran
- Cancer Gene Therapy Research Center (CGRC), Zanjan University of Medical Sciences, Zanjan 4513956111, Iran
- Immunotherapy Research & Technology Group, Zanjan University of Medical Sciences, Zanjan 4513956111, Iran
| | - Nazila Bahmaie
- Department of Allergy and Immunology, Faculty of Medicine, Graduate School of Health Science, Near East University (NEU), Nicosia 99138, Cyprus;
- Pediatric Ward, Department of Allergy and Immunology, Near East University affiliated Hospital, Nicosia 99138, Cyprus
- Serology and Immunology Ward, Clinical Diagnosis Laboratory, Private Baskent Hospital, Nicosia 99138, Cyprus
- Network of Immunity in Infection, Malignancy and Autoimmunity (NIIMA), Universal Scientific Education and Research Network (USERN), Tehran 1419733151, Iran
| | - Elham Nouri
- School of Paramedicine, Zanjan University of Medical Sciences, Zanjan 4513956111, Iran;
- Shahid Beheshti University Affiliated Hospital, Zanjan University of Medical Sciences, Zanjan 4513956111, Iran
| | - Mohammad Javad Hajkazemi
- School of Medicine, Zanjan University of Medical Sciences, Zanjan 4513956111, Iran; (M.J.H.); (M.Z.R.)
| | - Maryam Zareh Rafie
- School of Medicine, Zanjan University of Medical Sciences, Zanjan 4513956111, Iran; (M.J.H.); (M.Z.R.)
| |
Collapse
|
13
|
Ünsal P, Çerçi P, Açıkgöz ŞA, Keskin G, Ölmez Ü. Serum Levels of Interleukin-36 Alpha and Interleukin-36 Receptor
Antagonist In Behcet’s Syndrome. AKTUEL RHEUMATOL 2021. [DOI: 10.1055/a-1550-2069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Abstract
Background Behcet’s syndrome (BS) is a systemic vasculitic
disorder. This study aimed to investigate the levels of serum IL-36α and
IL-36Ra in patients with BS.
Material and Methods A total of 80 subjects (60 BS patients and 20 healthy
controls [HC]) were included.
Results The median IL-36α level was 0.11 ng/ml in
the BS group and 0.09 ng/ml in the HC group (p=0.058).
The mean IL-36Ra level was 13.62 pg/ml in the BS group and
13.26 pg/ml in the HC group (p=0.348). Serum IL-36Ra
levels of the active group were significantly higher (p=0.037). Patients
with oral ulcers and central nervous system involvement had higher serum IL36Ra
levels. In the BS group, a positive correlation was found between serum IL-36Ra
and CRP. In a multivariate analysis, the IL-36Ra level (OR=1.067;
95% CI=1.001–1.137; p=0.045) was independently
associated with disease activity.
Conclusion According to these findings, it is not clear whether such a
slight difference is clinically significant, but they suggest that the IL-36
cytokine family may play a role in the course of the disease.
Collapse
Affiliation(s)
- Pelin Ünsal
- Department of Internal Medicine, Ankara University Faculty of Medicine,
Ankara, Turkey
| | - Pamir Çerçi
- Department of Internal Medicine, Division of Immunology and Allergy,
Ankara University Faculty of Medicine, Ankara, Turkey
| | - Şükrü Alper Açıkgöz
- Department of Internal Medicine, Division of Immunology and Allergy,
Ankara University Faculty of Medicine, Ankara, Turkey
| | - Göksal Keskin
- Department of Internal Medicine, Division of Immunology and Allergy,
Ankara University Faculty of Medicine, Ankara, Turkey
| | - Ümit Ölmez
- Department of Internal Medicine, Division of Immunology and Allergy,
Ankara University Faculty of Medicine, Ankara, Turkey
| |
Collapse
|
14
|
Motz CT, Kabat V, Saxena T, Bellamkonda RV, Zhu C. Neuromechanobiology: An Expanding Field Driven by the Force of Greater Focus. Adv Healthc Mater 2021; 10:e2100102. [PMID: 34342167 PMCID: PMC8497434 DOI: 10.1002/adhm.202100102] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2021] [Revised: 07/06/2021] [Indexed: 12/14/2022]
Abstract
The brain processes information by transmitting signals through highly connected and dynamic networks of neurons. Neurons use specific cellular structures, including axons, dendrites and synapses, and specific molecules, including cell adhesion molecules, ion channels and chemical receptors to form, maintain and communicate among cells in the networks. These cellular and molecular processes take place in environments rich of mechanical cues, thus offering ample opportunities for mechanical regulation of neural development and function. Recent studies have suggested the importance of mechanical cues and their potential regulatory roles in the development and maintenance of these neuronal structures. Also suggested are the importance of mechanical cues and their potential regulatory roles in the interaction and function of molecules mediating the interneuronal communications. In this review, the current understanding is integrated and promising future directions of neuromechanobiology are suggested at the cellular and molecular levels. Several neuronal processes where mechanics likely plays a role are examined and how forces affect ligand binding, conformational change, and signal induction of molecules key to these neuronal processes are indicated, especially at the synapse. The disease relevance of neuromechanobiology as well as therapies and engineering solutions to neurological disorders stemmed from this emergent field of study are also discussed.
Collapse
Affiliation(s)
- Cara T Motz
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA, 30332-0363, USA
- Parker H. Petit Institute for Bioengineering and Biosciences, Georgia Institute of Technology, Atlanta, GA, 30332-0363, USA
| | - Victoria Kabat
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA, 30332-0363, USA
| | - Tarun Saxena
- Department of Biomedical Engineering, Duke University, Durham, NC, 27709, USA
| | - Ravi V Bellamkonda
- Department of Biomedical Engineering, Pratt School of Engineering, Duke University, Durham, NC, 27708, USA
| | - Cheng Zhu
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA, 30332-0363, USA
- Parker H. Petit Institute for Bioengineering and Biosciences, Georgia Institute of Technology, Atlanta, GA, 30332-0363, USA
- George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA, 30332-0363, USA
| |
Collapse
|
15
|
Duncan J, Sridharan A, Kumar SS, Iradukunda D, Muthuswamy J. Biomechanical micromotion at the neural interface modulates intracellular membrane potentials in vivo. J Neural Eng 2021; 18. [PMID: 34111852 DOI: 10.1088/1741-2552/ac0a56] [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: 03/14/2021] [Accepted: 06/10/2021] [Indexed: 11/12/2022]
Abstract
Objective. Respiration and vascular pulsation cause relative micromotion of brain tissue against stationary implants resulting in repetitive displacements of 2-4µm (due to vascular pulsation) and 10-30µm (due to breathing) in rats. However, the direct functional impact of such tissue micromotion on the cells at the neural interface remains unknown. This study aims to test the hypothesis that micromotion in brain tissue causes changes in membrane potentials (MPs) through the activation of mechanosensitive ion channels.Approach. Intracellular MPs were recorded from Aplysia ganglion cells (n= 8) and cortical cells (n= 15)in vivoinn= 7 adult rats. Cyclic stresses between 0.2 and 4 kPa repeated at 1 Hz were tested in Aplysia ganglion cells. For thein vivoexperiments, 30μM of gadolinium chloride (Gd3+), a non-selective blocker of mechanosensitive ion channels, was used to assess the role of such ion channels.Main results. In Aplysia ganglion cells, there were no MP changes for <1.5 kPa, and action potentials were observed at >3.1 kPa. Drug studies utilizing 5-HT showed an 80% reduction in firing frequency from controls. Inin vivoexperiments, periodic pulsations (1-10 mV) were observed in the MPs of cells that corresponded to breathing and heart-rate. In response to the addition of 30µM Gd3+, we observed a significant reduction (0.5-3 mV) in the periodic pulsations in MP in all cortical cells across four different rats, suggesting the role of mechanosensitive ion channels in mediating MP fluctuations due to tissue micromotion at the neural interface.Significance.Under chronic conditions, the tissue at the interface stiffens due to scar tissue formation, which is expected to increase the likelihood of recruiting stretch-receptors due to tissue micromotion. It is speculated that such chronic sub-threshold pulsations in MPs might trigger the immune response at the neural interface.
Collapse
Affiliation(s)
- Jonathan Duncan
- School of Biological and Health Systems Engineering, Arizona State University, Tempe, AZ 85287, United States of America
| | - Arati Sridharan
- School of Biological and Health Systems Engineering, Arizona State University, Tempe, AZ 85287, United States of America
| | - Swathy Sampath Kumar
- School of Biological and Health Systems Engineering, Arizona State University, Tempe, AZ 85287, United States of America
| | - Diane Iradukunda
- School of Biological and Health Systems Engineering, Arizona State University, Tempe, AZ 85287, United States of America
| | - Jit Muthuswamy
- School of Biological and Health Systems Engineering, Arizona State University, Tempe, AZ 85287, United States of America
| |
Collapse
|
16
|
Sridharan A, Muthuswamy J. Soft, Conductive, Brain-Like, Coatings at Tips of Microelectrodes Improve Electrical Stability under Chronic, In Vivo Conditions. MICROMACHINES 2021; 12:761. [PMID: 34203234 PMCID: PMC8306035 DOI: 10.3390/mi12070761] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Revised: 06/22/2021] [Accepted: 06/25/2021] [Indexed: 01/27/2023]
Abstract
Several recent studies have reported improved histological and electrophysiological outcomes with soft neural interfaces that have elastic moduli ranging from 10 s of kPa to hundreds of MPa. However, many of these soft interfaces use custom fabrication processes. We test the hypothesis that a readily adoptable fabrication process for only coating the tips of microelectrodes with soft brain-like (elastic modulus of ~5 kPa) material improves the long-term electrical performance of neural interfaces. Conventional tungsten microelectrodes (n = 9 with soft coatings and n = 6 uncoated controls) and Pt/Ir microelectrodes (n = 16 with soft coatings) were implanted in six animals for durations ranging from 5 weeks to over 1 year in a subset of rats. Electrochemical impedance spectroscopy was used to assess the quality of the brain tissue-electrode interface under chronic conditions. Neural recordings were assessed for unit activity and signal quality. Electrodes with soft, silicone coatings showed relatively stable electrical impedance characteristics over 6 weeks to >1 year compared to the uncoated control electrodes. Single unit activity recorded by coated electrodes showed larger peak-to-peak amplitudes and increased number of detectable neurons compared to uncoated controls over 6-7 weeks. We demonstrate the feasibility of using a readily translatable process to create brain-like soft interfaces that can potentially overcome variable performance associated with chronic rigid neural interfaces.
Collapse
Affiliation(s)
| | - Jit Muthuswamy
- School of Biological and Health Systems Engineering, Ira A. Fulton School of Engineering, Arizona State University, Tempe, AZ 85287-9709, USA;
| |
Collapse
|
17
|
Kim K, Sung C, Lee J, Won J, Jeon W, Seo S, Yoon K, Park S. Computational and Histological Analyses for Investigating Mechanical Interaction of Thermally Drawn Fiber Implants with Brain Tissue. MICROMACHINES 2021; 12:mi12040394. [PMID: 33918390 PMCID: PMC8067235 DOI: 10.3390/mi12040394] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Revised: 03/25/2021] [Accepted: 03/31/2021] [Indexed: 01/24/2023]
Abstract
The development of a compliant neural probe is necessary to achieve chronic implantation with minimal signal loss. Although fiber-based neural probes fabricated by the thermal drawing process have been proposed as a solution, their long-term effect on the brain has not been thoroughly investigated. Here, we examined the mechanical interaction of thermally drawn fiber implants with neural tissue through computational and histological analyses. Specifically, finite element analysis and immunohistochemistry were conducted to evaluate the biocompatibility of various fiber implants made with different base materials (steel, silica, polycarbonate, and hydrogel). Moreover, the effects of the coefficient of friction and geometric factors including aspect ratio and the shape of the cross-section on the strain were investigated with the finite element model. As a result, we observed that the fiber implants fabricated with extremely softer material such as hydrogel exhibited significantly lower strain distribution and elicited a reduced immune response. In addition, the implants with higher coefficient of friction (COF) and/or circular cross-sections showed a lower strain distribution and smaller critical volume. This work suggests the materials and design factors that need to be carefully considered to develop future fiber-based neural probes to minimize mechanical invasiveness.
Collapse
Affiliation(s)
- Kanghyeon Kim
- Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology (KAIST), Deajeon 34141, Korea; (K.K.); (C.S.); (W.J.)
| | - Changhoon Sung
- Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology (KAIST), Deajeon 34141, Korea; (K.K.); (C.S.); (W.J.)
| | - Jungjoon Lee
- Program of Brain and Cognitive Engineering, Korea Advanced Institute of Science and Technology (KAIST), Deajeon 34141, Korea; (J.L.); (J.W.)
| | - Joonhee Won
- Program of Brain and Cognitive Engineering, Korea Advanced Institute of Science and Technology (KAIST), Deajeon 34141, Korea; (J.L.); (J.W.)
| | - Woojin Jeon
- Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology (KAIST), Deajeon 34141, Korea; (K.K.); (C.S.); (W.J.)
| | - Seungbeom Seo
- Department of Electrical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Korea;
| | - Kyungho Yoon
- Center for Healthcare Robotics, Korea Institute of Science and Technology (KIST), Seoul 02792, Korea
- Division of Bio-Medical Science and Technology, KIST School, Korea University of Science and Technology, Seoul 02792, Korea
- Correspondence: (K.Y.); (S.P.)
| | - Seongjun Park
- Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology (KAIST), Deajeon 34141, Korea; (K.K.); (C.S.); (W.J.)
- Program of Brain and Cognitive Engineering, Korea Advanced Institute of Science and Technology (KAIST), Deajeon 34141, Korea; (J.L.); (J.W.)
- KAIST Institute of Health Science and Technology (KIHST), Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea
- Correspondence: (K.Y.); (S.P.)
| |
Collapse
|
18
|
Khodadadei F, Liu AP, Harris CA. A high-resolution real-time quantification of astrocyte cytokine secretion under shear stress for investigating hydrocephalus shunt failure. Commun Biol 2021; 4:387. [PMID: 33758339 PMCID: PMC7988003 DOI: 10.1038/s42003-021-01888-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Accepted: 02/11/2021] [Indexed: 12/18/2022] Open
Abstract
It has been hypothesized that physiological shear forces acting on medical devices implanted in the brain significantly accelerate the rate to device failure in patients with chronically indwelling neuroprosthetics. In hydrocephalus shunt devices, shear forces arise from cerebrospinal fluid flow. The shunt's unacceptably high failure rate is mostly due to obstruction with adherent inflammatory cells. Astrocytes are the dominant cell type bound directly to obstructing shunts, rapidly manipulating their activation via shear stress-dependent cytokine secretion. Here we developed a total internal reflection fluorescence microscopy combined with a microfluidic shear device chip (MSDC) for quantitative analysis and direct spatial-temporal mapping of secreted cytokines at the single-cell level under physiological shear stress to identify the root cause for shunt failure. Real-time secretion imaging at 1-min time intervals enabled successful detection of a significant increase of astrocyte IL-6 cytokine secretion under shear stress greater than 0.5 dyne/cm2, validating our hypothesis and highlighting the importance of reducing shear stress activation of cells.
Collapse
Affiliation(s)
- Fatemeh Khodadadei
- Dept. of Chemical Engineering and Materials Science, Wayne State University, Detroit, MI, USA
| | - Allen P Liu
- Dept. of Mechanical Engineering, University of Michigan, Ann Arbor, MI, USA
- Dept. of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA
- Dept. of Biophysics, University of Michigan, Ann Arbor, MI, USA
- Dept. of Cellular and Molecular Biology Program, University of Michigan, Ann Arbor, MI, USA
| | - Carolyn A Harris
- Dept. of Chemical Engineering and Materials Science, Wayne State University, Detroit, MI, USA.
- Dept. of Biomedical Engineering, Wayne State University, Detroit, MI, USA.
- Dept. of Neurosurgery, Wayne State University, Detroit, MI, USA.
| |
Collapse
|
19
|
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.
Collapse
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
| |
Collapse
|
20
|
Latchoumane CFV, Betancur MI, Simchick GA, Sun MK, Forghani R, Lenear CE, Ahmed A, Mohankumar R, Balaji N, Mason HD, Archer-Hartmann SA, Azadi P, Holmes PV, Zhao Q, Bellamkonda RV, Karumbaiah L. Engineered glycomaterial implants orchestrate large-scale functional repair of brain tissue chronically after severe traumatic brain injury. SCIENCE ADVANCES 2021; 7:7/10/eabe0207. [PMID: 33674306 PMCID: PMC7935369 DOI: 10.1126/sciadv.abe0207] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Accepted: 01/21/2021] [Indexed: 05/14/2023]
Abstract
Severe traumatic brain injury (sTBI) survivors experience permanent functional disabilities due to significant volume loss and the brain's poor capacity to regenerate. Chondroitin sulfate glycosaminoglycans (CS-GAGs) are key regulators of growth factor signaling and neural stem cell homeostasis in the brain. However, the efficacy of engineered CS (eCS) matrices in mediating structural and functional recovery chronically after sTBI has not been investigated. We report that neurotrophic factor functionalized acellular eCS matrices implanted into the rat M1 region acutely after sTBI significantly enhanced cellular repair and gross motor function recovery when compared to controls 20 weeks after sTBI. Animals subjected to M2 region injuries followed by eCS matrix implantations demonstrated the significant recovery of "reach-to-grasp" function. This was attributed to enhanced volumetric vascularization, activity-regulated cytoskeleton (Arc) protein expression, and perilesional sensorimotor connectivity. These findings indicate that eCS matrices implanted acutely after sTBI can support complex cellular, vascular, and neuronal circuit repair chronically after sTBI.
Collapse
Affiliation(s)
- Charles-Francois V Latchoumane
- Regenerative Bioscience Center, University of Georgia, Athens, GA 30602, USA
- Edgar L. Rhodes Center for ADS, College of Agriculture and Environmental Sciences, University of Georgia, Athens, GA 30602, USA
| | - Martha I Betancur
- Department of Biomedical Engineering, Pratt School of Engineering, Duke University, 101 Science Drive, Durham, NC 27705, USA
| | - Gregory A Simchick
- Department of Physics and Astronomy, University of Georgia, Athens, GA 30602, USA
- Bio-Imaging Research Center, University of Georgia, Athens, GA 30602, USA
| | - Min Kyoung Sun
- Regenerative Bioscience Center, University of Georgia, Athens, GA 30602, USA
- Division of Neuroscience, Biomedical & Health Sciences Institute, University of Georgia, Athens, GA 30602, USA
| | - Rameen Forghani
- Regenerative Bioscience Center, University of Georgia, Athens, GA 30602, USA
| | - Christopher E Lenear
- Regenerative Bioscience Center, University of Georgia, Athens, GA 30602, USA
- Edgar L. Rhodes Center for ADS, College of Agriculture and Environmental Sciences, University of Georgia, Athens, GA 30602, USA
| | - Aws Ahmed
- Regenerative Bioscience Center, University of Georgia, Athens, GA 30602, USA
- Edgar L. Rhodes Center for ADS, College of Agriculture and Environmental Sciences, University of Georgia, Athens, GA 30602, USA
| | - Ramya Mohankumar
- Regenerative Bioscience Center, University of Georgia, Athens, GA 30602, USA
| | - Nivedha Balaji
- Regenerative Bioscience Center, University of Georgia, Athens, GA 30602, USA
| | - Hannah D Mason
- Regenerative Bioscience Center, University of Georgia, Athens, GA 30602, USA
| | | | - Parastoo Azadi
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA 30602, USA
| | - Philip V Holmes
- Division of Neuroscience, Biomedical & Health Sciences Institute, University of Georgia, Athens, GA 30602, USA
- Psychology Department, University of Georgia, Athens, GA 30602, USA
| | - Qun Zhao
- Regenerative Bioscience Center, University of Georgia, Athens, GA 30602, USA
- Department of Physics and Astronomy, University of Georgia, Athens, GA 30602, USA
- Bio-Imaging Research Center, University of Georgia, Athens, GA 30602, USA
| | - Ravi V Bellamkonda
- Department of Biomedical Engineering, Pratt School of Engineering, Duke University, 101 Science Drive, Durham, NC 27705, USA
| | - Lohitash Karumbaiah
- Regenerative Bioscience Center, University of Georgia, Athens, GA 30602, USA.
- Edgar L. Rhodes Center for ADS, College of Agriculture and Environmental Sciences, University of Georgia, Athens, GA 30602, USA
- Division of Neuroscience, Biomedical & Health Sciences Institute, University of Georgia, Athens, GA 30602, USA
| |
Collapse
|
21
|
Xu L, Hu C, Huang Q, Jin K, Zhao P, Wang D, Hou W, Dong L, Hu S, Ma H. Trends and recent development of the microelectrode arrays (MEAs). Biosens Bioelectron 2021; 175:112854. [PMID: 33371989 DOI: 10.1016/j.bios.2020.112854] [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: 09/16/2020] [Revised: 11/20/2020] [Accepted: 11/23/2020] [Indexed: 11/27/2022]
Abstract
In this paper, we reviewed the history of microelectrode arrays (MEAs), compared different microfabrication techniques applied to modern MEAs in terms of their material characters, device properties and application scenarios. Then we discussed the biocompatibility of different MEAs as well as corresponding strategy of improvement. At last, we analyzed the growing trend of MEAs' technical route, expected application of MEAs in the field of Electrical impedance tomography (EIT).
Collapse
Affiliation(s)
- Longqian Xu
- CAS Key Laboratory of Bio-medical Diagnostics, Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, No.88 Keling Road, Suzhou, Jiangsu province, 215163, PR China
| | - Chenxuan Hu
- CAS Key Laboratory of Bio-medical Diagnostics, Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, No.88 Keling Road, Suzhou, Jiangsu province, 215163, PR China
| | - Qi Huang
- CAS Key Laboratory of Bio-medical Diagnostics, Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, No.88 Keling Road, Suzhou, Jiangsu province, 215163, PR China
| | - Kai Jin
- CAS Key Laboratory of Bio-medical Diagnostics, Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, No.88 Keling Road, Suzhou, Jiangsu province, 215163, PR China; International Joint Research Center for Nanophotonics and Biophotonics, School of Science, Changchun University of Science and Technology, Changchun, Jilin province, 130022, PR China
| | - Ping Zhao
- CAS Key Laboratory of Bio-medical Diagnostics, Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, No.88 Keling Road, Suzhou, Jiangsu province, 215163, PR China; International Joint Research Center for Nanophotonics and Biophotonics, School of Science, Changchun University of Science and Technology, Changchun, Jilin province, 130022, PR China
| | - Dongping Wang
- CAS Key Laboratory of Bio-medical Diagnostics, Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, No.88 Keling Road, Suzhou, Jiangsu province, 215163, PR China
| | - Wei Hou
- Department of Radiation Oncology & Therapy, The First Hospital of Jilin University, NO.1 Xinmin Street, Changchun, Jilin province, 130021, PR China
| | - Lihua Dong
- Department of Radiation Oncology & Therapy, The First Hospital of Jilin University, NO.1 Xinmin Street, Changchun, Jilin province, 130021, PR China
| | - Siyi Hu
- CAS Key Laboratory of Bio-medical Diagnostics, Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, No.88 Keling Road, Suzhou, Jiangsu province, 215163, PR China
| | - Hanbin Ma
- CAS Key Laboratory of Bio-medical Diagnostics, Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, No.88 Keling Road, Suzhou, Jiangsu province, 215163, PR China.
| |
Collapse
|
22
|
Atkinson D, D'Souza T, Rajput JS, Tasnim N, Muthuswamy J, Marvi H, Pancrazio JJ. Advances in Implantable Microelectrode Array Insertion and Positioning. Neuromodulation 2021; 25:789-795. [PMID: 33438369 DOI: 10.1111/ner.13355] [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: 09/11/2020] [Revised: 12/14/2020] [Accepted: 12/21/2020] [Indexed: 11/29/2022]
Abstract
OBJECTIVES Microelectrode arrays offer a means to probe the functional circuitry of the brain and the promise of cortical neuroprosthesis for individuals suffering from paralysis or limb loss. These devices are typically comprised of one or more shanks incorporating microelectrode sites, where the shanks are positioned by inserting the devices along a straight path that is normal to the brain surface. The lack of consistent long-term chronic recording technology has driven interest in novel probe design and approaches that go beyond the standard insertion approach that is limited to a single velocity or axis. This review offers a description of typical approaches and associated limitations and surveys emergent methods for implantation of microelectrode arrays, in particular those new approaches that leverage embedded microactuators and extend the insertion direction beyond a single axis. MATERIALS AND METHODS This review paper surveys the current technologies that enable probe implantation, repositioning, and the capability to record/stimulate from a tissue volume. A comprehensive literature search was performed using PubMed, Web of Science, and Google Scholar. RESULTS There has been substantial innovation in the development of microscale and embedded technology that enables probe repositioning to maintain quality recordings in the brain. Innovations in material science have resulted in novel strategies for deployable structures that can record from or stimulate a tissue volume. Moreover, new developments involving magnetically steerable catheters and needles offer an alternative approach to "pull" rather than "push" a probe into the tissue. CONCLUSION We envision the emergence of a new generation of probes and insertion methodologies for neuromodulation applications that enable reliable chronic performance from devices that can be positioned virtually anywhere in the brain.
Collapse
Affiliation(s)
- David Atkinson
- Department of Bioengineering, Erik Jonsson School of Engineering and Computer Science, The University of Texas at Dallas, Richardson, TX, USA
| | - Tania D'Souza
- Department of Bioengineering, Erik Jonsson School of Engineering and Computer Science, The University of Texas at Dallas, Richardson, TX, USA
| | - Jai Singh Rajput
- Department of Bioengineering, Erik Jonsson School of Engineering and Computer Science, The University of Texas at Dallas, Richardson, TX, USA
| | - Nishat Tasnim
- Department of Bioengineering, Erik Jonsson School of Engineering and Computer Science, The University of Texas at Dallas, Richardson, TX, USA
| | - Jit Muthuswamy
- Department of Biomedical Engineering, School of Biological and Health Systems, Engineering, Arizona State University, Tempe, AZ, USA
| | - Hamid Marvi
- School for Engineering of Matter Transport and Energy, Ira A. Fulton Schools of Engineering, Arizona State University, Tempe, AZ, USA
| | - Joseph J Pancrazio
- Department of Bioengineering, Erik Jonsson School of Engineering and Computer Science, The University of Texas at Dallas, Richardson, TX, USA
| |
Collapse
|
23
|
Yan T, Kameda S, Suzuki K, Kaiju T, Inoue M, Suzuki T, Hirata M. Minimal Tissue Reaction after Chronic Subdural Electrode Implantation for Fully Implantable Brain-Machine Interfaces. SENSORS 2020; 21:s21010178. [PMID: 33383864 PMCID: PMC7795822 DOI: 10.3390/s21010178] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/07/2020] [Revised: 12/12/2020] [Accepted: 12/25/2020] [Indexed: 11/16/2022]
Abstract
There is a growing interest in the use of electrocorticographic (ECoG) signals in brain–machine interfaces (BMIs). However, there is still a lack of studies involving the long-term evaluation of the tissue response related to electrode implantation. Here, we investigated biocompatibility, including chronic tissue response to subdural electrodes and a fully implantable wireless BMI device. We implanted a half-sized fully implantable device with subdural electrodes in six beagles for 6 months. Histological analysis of the surrounding tissues, including the dural membrane and cortices, was performed to evaluate the effects of chronic implantation. Our results showed no adverse events, including infectious signs, throughout the 6-month implantation period. Thick connective tissue proliferation was found in the surrounding tissues in the epidural space and subcutaneous space. Quantitative measures of subdural reactive tissues showed minimal encapsulation between the electrodes and the underlying cortex. Immunohistochemical evaluation showed no significant difference in the cell densities of neurons, astrocytes, and microglia between the implanted sites and contralateral sites. In conclusion, we established a beagle model to evaluate cortical implantable devices. We confirmed that a fully implantable wireless device and subdural electrodes could be stably maintained with sufficient biocompatibility in vivo.
Collapse
Affiliation(s)
- Tianfang Yan
- Department of Neurological Diagnosis and Restoration, Osaka University Graduate School of Medicine, Suita 565-0871, Japan; (T.Y.); (S.K.)
| | - Seiji Kameda
- Department of Neurological Diagnosis and Restoration, Osaka University Graduate School of Medicine, Suita 565-0871, Japan; (T.Y.); (S.K.)
- Global Center for Medical Engineering and Informatics, Osaka University, Suita 565-0871, Japan
- Department of Neurosurgery, Osaka University Graduate School of Medicine, Suita 565-0871, Japan
| | - Katsuyoshi Suzuki
- Ogino Memorial Laboratory, Nihon Kohden Corporation, Tokorozawa 359-0037, Japan;
| | - Taro Kaiju
- Center for Information and Neural Networks, National Institute of Information and Communications Technology, Suita 565-0871, Japan; (T.K.); (M.I.); (T.S.)
| | - Masato Inoue
- Center for Information and Neural Networks, National Institute of Information and Communications Technology, Suita 565-0871, Japan; (T.K.); (M.I.); (T.S.)
| | - Takafumi Suzuki
- Center for Information and Neural Networks, National Institute of Information and Communications Technology, Suita 565-0871, Japan; (T.K.); (M.I.); (T.S.)
| | - Masayuki Hirata
- Department of Neurological Diagnosis and Restoration, Osaka University Graduate School of Medicine, Suita 565-0871, Japan; (T.Y.); (S.K.)
- Global Center for Medical Engineering and Informatics, Osaka University, Suita 565-0871, Japan
- Department of Neurosurgery, Osaka University Graduate School of Medicine, Suita 565-0871, Japan
- Correspondence:
| |
Collapse
|
24
|
How is flexible electronics advancing neuroscience research? Biomaterials 2020; 268:120559. [PMID: 33310538 DOI: 10.1016/j.biomaterials.2020.120559] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Revised: 11/16/2020] [Accepted: 11/18/2020] [Indexed: 02/07/2023]
Abstract
Innovative neurotechnology must be leveraged to experimentally answer the multitude of pressing questions in modern neuroscience. Driven by the desire to address the existing neuroscience problems with newly engineered tools, we discuss in this review the benefits of flexible electronics for neuroscience studies. We first introduce the concept and define the properties of flexible and stretchable electronics. We then categorize the four dimensions where flexible electronics meets the demands of modern neuroscience: chronic stability, interfacing multiple structures, multi-modal compatibility, and neuron-type-specific recording. Specifically, with the bending stiffness now approaching that of neural tissue, implanted flexible electronic devices produce little shear motion, minimizing chronic immune responses and enabling recording and stimulation for months, and even years. The unique mechanical properties of flexible electronics also allow for intimate conformation to the brain, the spinal cord, peripheral nerves, and the retina. Moreover, flexible electronics enables optogenetic stimulation, microfluidic drug delivery, and neural activity imaging during electrical stimulation and recording. Finally, flexible electronics can enable neuron-type identification through analysis of high-fidelity recorded action potentials facilitated by its seamless integration with the neural circuitry. We argue that flexible electronics will play an increasingly important role in neuroscience studies and neurological therapies via the fabrication of neuromorphic devices on flexible substrates and the development of enhanced methods of neuronal interpenetration.
Collapse
|
25
|
Peng X, Pan X, Tan J, Li Y, Li M. Protective effect of interleukin-36 receptor antagonist on liver injury induced by concanavalin A in mice. IRANIAN JOURNAL OF BASIC MEDICAL SCIENCES 2020; 23:623-628. [PMID: 32742600 PMCID: PMC7374990 DOI: 10.22038/ijbms.2020.35614.8492] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Objective(s): Interleukin-36 receptor antagonist (IL-36Ra) is a new member of the IL-1 family that exhibits anti-inflammatory activity in a variety of inflammatory and immune diseases. Our purpose was to determine the effect of IL-36Ra on liver injury in a mouse hepatitis model induced by concanavalin A (ConA). Materials and Methods: Mice were treated with IL-36Ra DNA or pcDNA3.1 control plasmid using a hydrodynamic gene delivery approach. Results: Our data reveal that treatment with IL-36Ra decreased liver inflammation and serum level of aminotransferases. Furthermore, IL-36Ra reduced ConA-induced pro-inflammatory cytokines (interferon-γ, tumor necrosis factor-α, and IL-17A) production when compared to control plasmid. Conclusion: Our results demonstrated that IL-36Ra is a critical protector against ConA-induced liver injury.
Collapse
Affiliation(s)
- Xiao Peng
- Department of Immunology, Medical School of Ningbo University, Ningbo 315211, China
| | - Xiuhe Pan
- Department of Immunology, Medical School of Ningbo University, Ningbo 315211, China
| | - Jun Tan
- Department of Hepatology, HwaMei Hospital, University of Chinese Academy of Sciences, Ningbo 315010, China
| | - Yan Li
- Department of Immunology, Medical School of Ningbo University, Ningbo 315211, China
| | - Mingcai Li
- Department of Immunology, Medical School of Ningbo University, Ningbo 315211, China
| |
Collapse
|
26
|
Usoro JO, Shih E, Black BJ, Rihani RT, Abbott J, Chakraborty B, Pancrazio JJ, Cogan SF. Chronic stability of local field potentials from standard and modified Blackrock microelectrode arrays implanted in the rat motor cortex. Biomed Phys Eng Express 2019. [DOI: 10.1088/2057-1976/ab4c02] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
|
27
|
Ferguson M, Sharma D, Ross D, Zhao F. A Critical Review of Microelectrode Arrays and Strategies for Improving Neural Interfaces. Adv Healthc Mater 2019; 8:e1900558. [PMID: 31464094 PMCID: PMC6786932 DOI: 10.1002/adhm.201900558] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Revised: 07/25/2019] [Indexed: 12/19/2022]
Abstract
Though neural interface systems (NISs) can provide a potential solution for mitigating the effects of limb loss and central nervous system damage, the microelectrode array (MEA) component of NISs remains a significant limiting factor to their widespread clinical applications. Several strategies can be applied to MEA designs to increase their biocompatibility. Herein, an overview of NISs and their applications is provided, along with a detailed discussion of strategies for alleviating the foreign body response (FBR) and abnormalities seen at the interface of MEAs and the brain tissue following MEA implantation. Various surface modifications, including natural/synthetic surface coatings, hydrogels, and topography alterations, have shown to be highly successful in improving neural cell adhesion, reducing gliosis, and increasing MEA longevity. Different MEA surface geometries, such as those seen in the Utah and Michigan arrays, can help alleviate the resultant FBR by reducing insertion damage, while providing new avenues for improving MEA recording performance and resolution. Increasing overall flexibility of MEAs as well as reducing their stiffness is also shown to reduce MEA induced micromotion along with FBR severity. By combining multiple different properties into a single MEA, the severity and duration of an FBR postimplantation can be reduced substantially.
Collapse
Affiliation(s)
- Morgan Ferguson
- Department of Biomedical Engineering, Michigan Technological University, 1400 Townsend Dr., Houghton, MI 49931
| | - Dhavan Sharma
- Department of Biomedical Engineering, Michigan Technological University, 1400 Townsend Dr., Houghton, MI 49931
| | - David Ross
- Department of Biomedical Engineering, Michigan Technological University, 1400 Townsend Dr., Houghton, MI 49931
| | - Feng Zhao
- Department of Biomedical Engineering, Michigan Technological University, 1400 Townsend Dr., Houghton, MI 49931
| |
Collapse
|
28
|
Method for spike detection from microelectrode array recordings contaminated by artifacts of simultaneous two-photon imaging. PLoS One 2019; 14:e0221510. [PMID: 31430357 PMCID: PMC6701834 DOI: 10.1371/journal.pone.0221510] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Accepted: 08/09/2019] [Indexed: 11/19/2022] Open
Abstract
The simultaneous utilization of electrophysiological recordings and two-photon imaging allows the observation of neural activity in a high temporal and spatial resolution at the same time. The three dimensional monitoring of morphological features near the microelectrode array makes the observation more precise and complex. In vitro experiments were performed on mice neocortical slices expressing the GCaMP6 genetically encoded calcium indicator for monitoring the neural activity with two-photon microscopy around the implanted microelectrodes. A special filtering algorithm was used for data analysis to eliminate the artefacts caused by the imaging laser. Utilization of a special filtering algorithm allowed us to detect and sort single unit activities from simultaneous two-photon imaging and electrophysiological measurement.
Collapse
|
29
|
Wellman SM, Li L, Yaxiaer Y, McNamara I, Kozai TDY. Revealing Spatial and Temporal Patterns of Cell Death, Glial Proliferation, and Blood-Brain Barrier Dysfunction Around Implanted Intracortical Neural Interfaces. Front Neurosci 2019; 13:493. [PMID: 31191216 PMCID: PMC6546924 DOI: 10.3389/fnins.2019.00493] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Accepted: 04/29/2019] [Indexed: 12/11/2022] Open
Abstract
Improving the long-term performance of neural electrode interfaces requires overcoming severe biological reactions such as neuronal cell death, glial cell activation, and vascular damage in the presence of implanted intracortical devices. Past studies traditionally observe neurons, microglia, astrocytes, and blood-brain barrier (BBB) disruption around inserted microelectrode arrays. However, analysis of these factors alone yields poor correlation between tissue inflammation and device performance. Additionally, these studies often overlook significant biological responses that can occur during acute implantation injury. The current study employs additional histological markers that provide novel information about neglected tissue components-oligodendrocytes and their myelin structures, oligodendrocyte precursor cells, and BBB -associated pericytes-during the foreign body response to inserted devices at 1, 3, 7, and 28 days post-insertion. Our results reveal unique temporal and spatial patterns of neuronal and oligodendrocyte cell loss, axonal and myelin reorganization, glial cell reactivity, and pericyte deficiency both acutely and chronically around implanted devices. Furthermore, probing for immunohistochemical markers that highlight mechanisms of cell death or patterns of proliferation and differentiation have provided new insight into inflammatory tissue dynamics around implanted intracortical electrode arrays.
Collapse
Affiliation(s)
- Steven M. Wellman
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, United States
- Center for the Neural Basis of Cognition, Pittsburgh, PA, United States
| | - Lehong Li
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, United States
| | - Yalikun Yaxiaer
- Eberly College of Science, Pennsylvania State University, University Park, PA, United States
| | - Ingrid McNamara
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, United States
| | - Takashi D. Y. Kozai
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, United States
- Center for the Neural Basis of Cognition, Pittsburgh, PA, United States
- Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA, United States
- McGowan Institute of Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA, United States
- NeuroTech Center, University of Pittsburgh Brain Institute, Pittsburgh, PA, United States
| |
Collapse
|
30
|
Black BJ, Ecker M, Stiller A, Rihani R, Danda VR, Reed I, Voit WE, Pancrazio JJ. In vitro compatibility testing of thiol-ene/acrylate-based shape memory polymers for use in implantable neural interfaces. J Biomed Mater Res A 2018; 106:2891-2898. [PMID: 30371968 DOI: 10.1002/jbm.a.36478] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2017] [Revised: 05/06/2018] [Accepted: 05/24/2018] [Indexed: 12/26/2022]
Abstract
Shape memory polymers (SMPs) based on thiol-ene/acrylate formulations are an emerging class of materials with potential applications as structural and/or dielectric coatings for implantable neural interfaces. Here, we report in vitro compatibility studies of three novel thiol-ene/acrylate-based SMP formulations. In vivo cytotoxicity assays were carried out in accordance with International Organization for Standards (ISO) protocol 10993-5, using NCTC clone 929 fibroblasts as well as embryonic cortical cultures. All three SMP formulations passed standardized cytotoxicity assays (>70% normalized cell viability) using both cell types. Functional neurotoxicity assays were carried out using primary cortical networks cultured on substrate-integrated microelectrode arrays (MEAs). We observed significant reduction in cortical network activity in the case of positive control material, but no significant alterations in activity following incubation with SMP material extracts, indicating functional cytocompatibility. Finally, we assessed cell reactivity at the tissue-material interface by performing an in vitro glial scarring assay. Through immunostaining, we observed similar astrocyte-associated (GFAP) mean intensity ratios near nonsoftening SMP-coated and uncoated stainless steel microwires (1.10 ± 0.06 vs. 1.19 ± 0.10), suggesting similar glial cell reactivity. However, we observed decreased mean intensity ratios in the presence of fully softening SMP-coated microwires (1.02 ± 0.04) suggesting reduced glial cell reactivity. Overall, these results indicate that the thiol-ene/acrylate SMP formulations presented here are neither cytotoxic nor neurotoxic, and suggest that fully softening SMP may reduce foreign body response in terms of glial cell reactivity. These findings support further consideration of this class of materials as backbone or insulating materials for implantable neural stimulating/recording devices. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 2891-2898, 2018.
Collapse
Affiliation(s)
- Bryan J Black
- Department of Bioengineering, The University of Texas at Dallas, 800 W. Campbell Road, Bioengineering and Sciences Building 13.633, Richardson, Texas, 75080
| | - Melanie Ecker
- Department of Bioengineering, The University of Texas at Dallas, 800 W. Campbell Road, Bioengineering and Sciences Building 13.633, Richardson, Texas, 75080
| | - Allison Stiller
- Department of Bioengineering, The University of Texas at Dallas, 800 W. Campbell Road, Bioengineering and Sciences Building 13.633, Richardson, Texas, 75080
| | - Rashed Rihani
- Department of Bioengineering, The University of Texas at Dallas, 800 W. Campbell Road, Bioengineering and Sciences Building 13.633, Richardson, Texas, 75080
| | - Vindhya Reddy Danda
- Department of Bioengineering, The University of Texas at Dallas, 800 W. Campbell Road, Bioengineering and Sciences Building 13.633, Richardson, Texas, 75080
| | - Isabella Reed
- Department of Bioengineering, The University of Texas at Dallas, 800 W. Campbell Road, Bioengineering and Sciences Building 13.633, Richardson, Texas, 75080
| | - Walter E Voit
- Department of Bioengineering, The University of Texas at Dallas, 800 W. Campbell Road, Bioengineering and Sciences Building 13.633, Richardson, Texas, 75080
| | - Joseph J Pancrazio
- Department of Bioengineering, The University of Texas at Dallas, 800 W. Campbell Road, Bioengineering and Sciences Building 13.633, Richardson, Texas, 75080
| |
Collapse
|
31
|
Renz AF, Reichmuth AM, Stauffer F, Thompson-Steckel G, Vörös J. A guide towards long-term functional electrodes interfacing neuronal tissue. J Neural Eng 2018; 15:061001. [DOI: 10.1088/1741-2552/aae0c2] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
|
32
|
Stiller AM, Usoro J, Frewin CL, Danda VR, Ecker M, Joshi-Imre A, Musselman KC, Voit W, Modi R, Pancrazio JJ, Black BJ. Chronic Intracortical Recording and Electrochemical Stability of Thiol-ene/Acrylate Shape Memory Polymer Electrode Arrays. MICROMACHINES 2018; 9:E500. [PMID: 30424433 PMCID: PMC6215160 DOI: 10.3390/mi9100500] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/18/2018] [Revised: 09/24/2018] [Accepted: 09/27/2018] [Indexed: 11/20/2022]
Abstract
Current intracortical probe technology is limited in clinical implementation due to the short functional lifetime of implanted devices. Devices often fail several months to years post-implantation, likely due to the chronic immune response characterized by glial scarring and neuronal dieback. It has been demonstrated that this neuroinflammatory response is influenced by the mechanical mismatch between stiff devices and the soft brain tissue, spurring interest in the use of softer polymer materials for probe encapsulation. Here, we demonstrate stable recordings and electrochemical properties obtained from fully encapsulated shape memory polymer (SMP) intracortical electrodes implanted in the rat motor cortex for 13 weeks. SMPs are a class of material that exhibit modulus changes when exposed to specific conditions. The formulation used in these devices softens by an order of magnitude after implantation compared to its dry, room-temperature modulus of ~2 GPa.
Collapse
Affiliation(s)
- Allison M Stiller
- Department of Bioengineering, The University of Texas at Dallas, Richardson, TX 75080, USA.
| | - Joshua Usoro
- Department of Bioengineering, The University of Texas at Dallas, Richardson, TX 75080, USA.
| | - Christopher L Frewin
- Department of Bioengineering, The University of Texas at Dallas, Richardson, TX 75080, USA.
| | - Vindhya R Danda
- Department of Bioengineering, The University of Texas at Dallas, Richardson, TX 75080, USA.
- Qualia, Inc., Dallas, TX 75252, USA.
| | - Melanie Ecker
- Department of Materials Science and Engineering, The University of Texas at Dallas, Richardson, TX 75080, USA.
| | - Alexandra Joshi-Imre
- Department of Bioengineering, The University of Texas at Dallas, Richardson, TX 75080, USA.
| | - Kate C Musselman
- Department of Bioengineering, The University of Texas at Dallas, Richardson, TX 75080, USA.
| | - Walter Voit
- Qualia, Inc., Dallas, TX 75252, USA.
- Department of Materials Science and Engineering, The University of Texas at Dallas, Richardson, TX 75080, USA.
| | | | - Joseph J Pancrazio
- Department of Bioengineering, The University of Texas at Dallas, Richardson, TX 75080, USA.
| | - Bryan J Black
- Department of Bioengineering, The University of Texas at Dallas, Richardson, TX 75080, USA.
| |
Collapse
|
33
|
Kozai TDY. The History and Horizons of Microscale Neural Interfaces. MICROMACHINES 2018; 9:E445. [PMID: 30424378 PMCID: PMC6187275 DOI: 10.3390/mi9090445] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Revised: 08/27/2018] [Accepted: 09/03/2018] [Indexed: 12/29/2022]
Abstract
Microscale neural technologies interface with the nervous system to record and stimulate brain tissue with high spatial and temporal resolution. These devices are being developed to understand the mechanisms that govern brain function, plasticity and cognitive learning, treat neurological diseases, or monitor and restore functions over the lifetime of the patient. Despite decades of use in basic research over days to months, and the growing prevalence of neuromodulation therapies, in many cases the lack of knowledge regarding the fundamental mechanisms driving activation has dramatically limited our ability to interpret data or fine-tune design parameters to improve long-term performance. While advances in materials, microfabrication techniques, packaging, and understanding of the nervous system has enabled tremendous innovation in the field of neural engineering, many challenges and opportunities remain at the frontiers of the neural interface in terms of both neurobiology and engineering. In this short-communication, we explore critical needs in the neural engineering field to overcome these challenges. Disentangling the complexities involved in the chronic neural interface problem requires simultaneous proficiency in multiple scientific and engineering disciplines. The critical component of advancing neural interface knowledge is to prepare the next wave of investigators who have simultaneous multi-disciplinary proficiencies with a diverse set of perspectives necessary to solve the chronic neural interface challenge.
Collapse
Affiliation(s)
- Takashi D Y Kozai
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA 15261, USA.
- Center for the Neural Basis of Cognition, University of Pittsburgh, Pittsburgh, PA 15213, USA.
- Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA 15261, USA.
- McGowan Institute of Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA 15212, USA.
- NeuroTech Center, University of Pittsburgh Brain Institute, Pittsburgh, PA 15260, USA.
| |
Collapse
|
34
|
Chronically Implanted Intracranial Electrodes: Tissue Reaction and Electrical Changes. MICROMACHINES 2018; 9:mi9090430. [PMID: 30424363 PMCID: PMC6187588 DOI: 10.3390/mi9090430] [Citation(s) in RCA: 65] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Revised: 08/13/2018] [Accepted: 08/22/2018] [Indexed: 12/28/2022]
Abstract
The brain-electrode interface is arguably one of the most important areas of study in neuroscience today. A stronger foundation in this topic will allow us to probe the architecture of the brain in unprecedented functional detail and augment our ability to intervene in disease states. Over many years, significant progress has been made in this field, but some obstacles have remained elusive—notably preventing glial encapsulation and electrode degradation. In this review, we discuss the tissue response to electrode implantation on acute and chronic timescales, the electrical changes that occur in electrode systems over time, and strategies that are being investigated in order to minimize the tissue response to implantation and maximize functional electrode longevity. We also highlight the current and future clinical applications and relevance of electrode technology.
Collapse
|
35
|
Michelson NJ, Vazquez AL, Eles JR, Salatino JW, Purcell EK, Williams JJ, Cui XT, Kozai TDY. Multi-scale, multi-modal analysis uncovers complex relationship at the brain tissue-implant neural interface: new emphasis on the biological interface. J Neural Eng 2018; 15:033001. [PMID: 29182149 PMCID: PMC5967409 DOI: 10.1088/1741-2552/aa9dae] [Citation(s) in RCA: 89] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
OBJECTIVE Implantable neural electrode devices are important tools for neuroscience research and have an increasing range of clinical applications. However, the intricacies of the biological response after implantation, and their ultimate impact on recording performance, remain challenging to elucidate. Establishing a relationship between the neurobiology and chronic recording performance is confounded by technical challenges related to traditional electrophysiological, material, and histological limitations. This can greatly impact the interpretations of results pertaining to device performance and tissue health surrounding the implant. APPROACH In this work, electrophysiological activity and immunohistological analysis are compared after controlling for motion artifacts, quiescent neuronal activity, and material failure of devices in order to better understand the relationship between histology and electrophysiological outcomes. MAIN RESULTS Even after carefully accounting for these factors, the presence of viable neurons and lack of glial scarring does not convey single unit recording performance. SIGNIFICANCE To better understand the biological factors influencing neural activity, detailed cellular and molecular tissue responses were examined. Decreases in neural activity and blood oxygenation in the tissue surrounding the implant, shift in expression levels of vesicular transporter proteins and ion channels, axon and myelin injury, and interrupted blood flow in nearby capillaries can impact neural activity around implanted neural interfaces. Combined, these tissue changes highlight the need for more comprehensive, basic science research to elucidate the relationship between biology and chronic electrophysiology performance in order to advance neural technologies.
Collapse
Affiliation(s)
| | - Alberto L Vazquez
- Department of Bioengineering, University of Pittsburgh
- Department of Radiology, University of Pittsburgh
- Center for the Neural Basis of Cognition, University of Pittsburgh
- Center for Neuroscience, University of Pittsburgh
| | - James R Eles
- Department of Bioengineering, University of Pittsburgh
- Center for the Neural Basis of Cognition, University of Pittsburgh
| | | | - Erin K Purcell
- Department of Biomedical Engineering, Michigan State University
| | | | - X. Tracy Cui
- Department of Bioengineering, University of Pittsburgh
- Center for the Neural Basis of Cognition, University of Pittsburgh
- McGowan Institute of Regenerative Medicine, University of Pittsburgh
| | - Takashi DY Kozai
- Department of Bioengineering, University of Pittsburgh
- Center for the Neural Basis of Cognition, University of Pittsburgh
- Center for Neuroscience, University of Pittsburgh
- McGowan Institute of Regenerative Medicine, University of Pittsburgh
- NeuroTech Center, University of Pittsburgh Brain Institute
| |
Collapse
|
36
|
Wellman SM, Eles JR, Ludwig KA, Seymour JP, Michelson NJ, McFadden WE, Vazquez AL, Kozai TDY. A Materials Roadmap to Functional Neural Interface Design. ADVANCED FUNCTIONAL MATERIALS 2018; 28:1701269. [PMID: 29805350 PMCID: PMC5963731 DOI: 10.1002/adfm.201701269] [Citation(s) in RCA: 181] [Impact Index Per Article: 30.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Advancement in neurotechnologies for electrophysiology, neurochemical sensing, neuromodulation, and optogenetics are revolutionizing scientific understanding of the brain while enabling treatments, cures, and preventative measures for a variety of neurological disorders. The grand challenge in neural interface engineering is to seamlessly integrate the interface between neurobiology and engineered technology, to record from and modulate neurons over chronic timescales. However, the biological inflammatory response to implants, neural degeneration, and long-term material stability diminish the quality of interface overtime. Recent advances in functional materials have been aimed at engineering solutions for chronic neural interfaces. Yet, the development and deployment of neural interfaces designed from novel materials have introduced new challenges that have largely avoided being addressed. Many engineering efforts that solely focus on optimizing individual probe design parameters, such as softness or flexibility, downplay critical multi-dimensional interactions between different physical properties of the device that contribute to overall performance and biocompatibility. Moreover, the use of these new materials present substantial new difficulties that must be addressed before regulatory approval for use in human patients will be achievable. In this review, the interdependence of different electrode components are highlighted to demonstrate the current materials-based challenges facing the field of neural interface engineering.
Collapse
Affiliation(s)
- Steven M Wellman
- Department of Bioengineering, Center for the Basis of Neural Cognition, McGowan Institute of Regenerative Medicine, NeuroTech Center, University of Pittsburgh Brain Institute, Center for Neuroscience at the University of Pittsburgh, University of Pittsburgh, 208 Center for Biotechnology, 300 Technology Dr., Pittsburgh, PA 15219, United States
| | - James R Eles
- Department of Bioengineering, Center for the Basis of Neural Cognition, McGowan Institute of Regenerative Medicine, NeuroTech Center, University of Pittsburgh Brain Institute, Center for Neuroscience at the University of Pittsburgh, University of Pittsburgh, 208 Center for Biotechnology, 300 Technology Dr., Pittsburgh, PA 15219, United States
| | - Kip A Ludwig
- Department of Neurologic Surgery, 200 First St. SW, Rochester, MN 55905
| | - John P Seymour
- Electrical & Computer Engineering, 1301 Beal Ave., 2227 EECS, Ann Arbor, MI 48109
| | - Nicholas J Michelson
- Department of Bioengineering, Center for the Basis of Neural Cognition, McGowan Institute of Regenerative Medicine, NeuroTech Center, University of Pittsburgh Brain Institute, Center for Neuroscience at the University of Pittsburgh, University of Pittsburgh, 208 Center for Biotechnology, 300 Technology Dr., Pittsburgh, PA 15219, United States
| | - William E McFadden
- Department of Bioengineering, Center for the Basis of Neural Cognition, McGowan Institute of Regenerative Medicine, NeuroTech Center, University of Pittsburgh Brain Institute, Center for Neuroscience at the University of Pittsburgh, University of Pittsburgh, 208 Center for Biotechnology, 300 Technology Dr., Pittsburgh, PA 15219, United States
| | - Alberto L Vazquez
- Department of Bioengineering, Center for the Basis of Neural Cognition, McGowan Institute of Regenerative Medicine, NeuroTech Center, University of Pittsburgh Brain Institute, Center for Neuroscience at the University of Pittsburgh, University of Pittsburgh, 208 Center for Biotechnology, 300 Technology Dr., Pittsburgh, PA 15219, United States
| | - Takashi D Y Kozai
- Department of Bioengineering, Center for the Basis of Neural Cognition, McGowan Institute of Regenerative Medicine, NeuroTech Center, University of Pittsburgh Brain Institute, Center for Neuroscience at the University of Pittsburgh, University of Pittsburgh, 208 Center for Biotechnology, 300 Technology Dr., Pittsburgh, PA 15219, United States
| |
Collapse
|
37
|
Abstract
The focus of this paper is to describe the mechanism and behavior of two-dimensional in vitro cell stretch platforms, as well as discussing designs for the evaluation of mechanical properties of cells. It is extremely important to understand the cellular response to extrinsic mechanical forces as living biological system is constantly subjected to mechanical forces in vivo. In addition, this mechanistic understanding of cellular response will provide valuable information towards the design and fabrication of bioengineered tissues and organs, which are expected to replace and/or aid bodily functions. This paper will primarily focus on the development, advantages and limitations of two-dimensional cell stretch platforms.
Collapse
Affiliation(s)
- H. GHAZIZADEH
- Joint School of Nanoscience and Nanoengineering, North Carolina A&T State University, 2907 East Gate City Blvd., Greensboro, NC 27401, USA
| | - S. ARAVAMUDHAN
- Joint School of Nanoscience and Nanoengineering, North Carolina A&T State University, 2907 East Gate City Blvd., Greensboro, NC 27401, USA
| |
Collapse
|
38
|
Woeppel K, Yang Q, Cui XT. Recent Advances in Neural Electrode-Tissue Interfaces. CURRENT OPINION IN BIOMEDICAL ENGINEERING 2017; 4:21-31. [PMID: 29423457 PMCID: PMC5798641 DOI: 10.1016/j.cobme.2017.09.003] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Neurotechnology is facing an exponential growth in the recent decades. Neural electrode-tissue interface research has been well recognized as an instrumental component of neurotechnology development. While satisfactory long-term performance was demonstrated in some applications, such as cochlear implants and deep brain stimulators, more advanced neural electrode devices requiring higher resolution for single unit recording or microstimulation still face significant challenges in reliability and longevity. In this article, we review the most recent findings that contribute to our current understanding of the sources of poor reliability and longevity in neural recording or stimulation, including the material failure, biological tissue response and the interplay between the two. The newly developed characterization tools are introduced from electrophysiology models, molecular and biochemical analysis, material characterization to live imaging. The effective strategies that have been applied to improve the interface are also highlighted. Finally, we discuss the challenges and opportunities in improving the interface and achieving seamless integration between the implanted electrodes and neural tissue both anatomically and functionally.
Collapse
Affiliation(s)
- Kevin Woeppel
- Bioengineering, University of Pittsburgh
- Center for the Neural Basis of Cognition, University of Pittsburgh
| | - Qianru Yang
- Bioengineering, University of Pittsburgh
- Center for the Neural Basis of Cognition, University of Pittsburgh
| | - Xinyan Tracy Cui
- Bioengineering, University of Pittsburgh
- Center for the Neural Basis of Cognition, University of Pittsburgh
- McGowan Institute for Regenerative Medicine, University of Pittsburgh
| |
Collapse
|
39
|
Salatino JW, Ludwig KA, Kozai TDY, Purcell EK. Glial responses to implanted electrodes in the brain. Nat Biomed Eng 2017; 1:862-877. [PMID: 30505625 PMCID: PMC6261524 DOI: 10.1038/s41551-017-0154-1] [Citation(s) in RCA: 305] [Impact Index Per Article: 43.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Accepted: 10/04/2017] [Indexed: 01/20/2023]
Abstract
The use of implants that can electrically stimulate or record electrophysiological or neurochemical activity in nervous tissue is rapidly expanding. Despite remarkable results in clinical studies and increasing market approvals, the mechanisms underlying the therapeutic effects of neuroprosthetic and neuromodulation devices, as well as their side effects and reasons for their failure, remain poorly understood. A major assumption has been that the signal-generating neurons are the only important target cells of neural-interface technologies. However, recent evidence indicates that the supporting glial cells remodel the structure and function of neuronal networks and are an effector of stimulation-based therapy. Here, we reframe the traditional view of glia as a passive barrier, and discuss their role as an active determinant of the outcomes of device implantation. We also discuss the implications that this has on the development of bioelectronic medical devices.
Collapse
Affiliation(s)
- Joseph W. Salatino
- Department of Biomedical Engineering, Michigan State University, East Lansing, MI, USA
- Institute for Quantitative Health Science and Engineering, Michigan State University, East Lansing, MI, USA
| | - Kip A. Ludwig
- Department of Neurologic Surgery, Mayo Clinic, Rochester, MN, USA
| | - Takashi D. Y. Kozai
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA
- Center for the Neural Basis of Cognition, 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
| | - Erin K. Purcell
- Department of Biomedical Engineering, Michigan State University, East Lansing, MI, USA
- Institute for Quantitative Health Science and Engineering, Michigan State University, East Lansing, MI, USA
- Department of Electrical and Computer Engineering, Michigan State University, East Lansing, MI, USA
- Neuroscience Program, Michigan State University, East Lansing, MI, USA
| |
Collapse
|
40
|
Characterization of Mechanically Matched Hydrogel Coatings to Improve the Biocompatibility of Neural Implants. Sci Rep 2017; 7:1952. [PMID: 28512291 PMCID: PMC5434064 DOI: 10.1038/s41598-017-02107-2] [Citation(s) in RCA: 96] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Accepted: 04/07/2017] [Indexed: 01/01/2023] Open
Abstract
Glial scar is a significant barrier to neural implant function. Micromotion between the implant and tissue is suspected to be a key driver of glial scar formation around neural implants. This study explores the ability of soft hydrogel coatings to modulate glial scar formation by reducing local strain. PEG hydrogels with controllable thickness and elastic moduli were formed on the surface of neural probes. These coatings significantly reduced the local strain resulting from micromotion around the implants. Coated implants were found to significantly reduce scarring in vivo, compared to hard implants of identical diameter. Increasing implant diameter was found to significantly increase scarring for glass implants, as well as increase local BBB permeability, increase macrophage activation, and decrease the local neural density. These results highlight the tradeoff in mechanical benefit with the size effects from increasing the overall diameter following the addition of a hydrogel coating. This study emphasizes the importance of both mechanical and geometric factors of neural implants on chronic timescales.
Collapse
|
41
|
Du ZJ, Kolarcik CL, Kozai TDY, Luebben SD, Sapp SA, Zheng XS, Nabity JA, Cui XT. Ultrasoft microwire neural electrodes improve chronic tissue integration. Acta Biomater 2017; 53:46-58. [PMID: 28185910 DOI: 10.1016/j.actbio.2017.02.010] [Citation(s) in RCA: 109] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2016] [Revised: 02/02/2017] [Accepted: 02/05/2017] [Indexed: 12/11/2022]
Abstract
Chronically implanted neural multi-electrode arrays (MEA) are an essential technology for recording electrical signals from neurons and/or modulating neural activity through stimulation. However, current MEAs, regardless of the type, elicit an inflammatory response that ultimately leads to device failure. Traditionally, rigid materials like tungsten and silicon have been employed to interface with the relatively soft neural tissue. The large stiffness mismatch is thought to exacerbate the inflammatory response. In order to minimize the disparity between the device and the brain, we fabricated novel ultrasoft electrodes consisting of elastomers and conducting polymers with mechanical properties much more similar to those of brain tissue than previous neural implants. In this study, these ultrasoft microelectrodes were inserted and released using a stainless steel shuttle with polyethyleneglycol (PEG) glue. The implanted microwires showed functionality in acute neural stimulation. When implanted for 1 or 8weeks, the novel soft implants demonstrated significantly reduced inflammatory tissue response at week 8 compared to tungsten wires of similar dimension and surface chemistry. Furthermore, a higher degree of cell body distortion was found next to the tungsten implants compared to the polymer implants. Our results support the use of these novel ultrasoft electrodes for long term neural implants. STATEMENT OF SIGNIFICANCE One critical challenge to the translation of neural recording/stimulation electrode technology to clinically viable devices for brain computer interface (BCI) or deep brain stimulation (DBS) applications is the chronic degradation of device performance due to the inflammatory tissue reaction. While many hypothesize that soft and flexible devices elicit reduced inflammatory tissue responses, there has yet to be a rigorous comparison between soft and stiff implants. We have developed an ultra-soft microelectrode with Young's modulus lower than 1MPa, closely mimicking the brain tissue modulus. Here, we present a rigorous histological comparison of this novel ultrasoft electrode and conventional stiff electrode with the same size, shape and surface chemistry, implanted in rat brains for 1-week and 8-weeks. Significant improvement was observed for ultrasoft electrodes, including inflammatory tissue reaction, electrode-tissue integration as well as mechanical disturbance to nearby neurons. A full spectrum of new techniques were developed in this study, from insertion shuttle to in situ sectioning of the microelectrode to automated cell shape analysis, all of which should contribute new methods to the field. Finally, we showed the electrical functionality of the ultrasoft electrode, demonstrating the potential of flexible neural implant devices for future research and clinical use.
Collapse
Affiliation(s)
- Zhanhong Jeff Du
- Department of Bioengineering, University of Pittsburgh, PA, USA; Center for the Neural Basis of Cognition, University of Pittsburgh, PA, USA; McGowan Institute for Regenerative Medicine, University of Pittsburgh, PA, USA; Shenzhen Key Lab of Neuropsychiatric Modulation, CAS Center for Excellence in Brain Science, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Christi L Kolarcik
- Department of Bioengineering, University of Pittsburgh, PA, USA; Center for the Neural Basis of Cognition, University of Pittsburgh, PA, USA; McGowan Institute for Regenerative Medicine, University of Pittsburgh, PA, USA; Systems Neuroscience Institute, University of Pittsburgh, PA, USA
| | - Takashi D Y Kozai
- Department of Bioengineering, University of Pittsburgh, PA, USA; Center for the Neural Basis of Cognition, University of Pittsburgh, PA, USA; McGowan Institute for Regenerative Medicine, University of Pittsburgh, PA, USA; NeuroTech Center of Brain Institute, University of Pittsburgh, PA, USA
| | | | | | - Xin Sally Zheng
- Department of Bioengineering, University of Pittsburgh, PA, USA
| | - James A Nabity
- Department of Aerospace Engineering Sciences, University of Colorado, Boulder, CO,USA
| | - X Tracy Cui
- Department of Bioengineering, University of Pittsburgh, PA, USA; Center for the Neural Basis of Cognition, University of Pittsburgh, PA, USA; McGowan Institute for Regenerative Medicine, University of Pittsburgh, PA, USA.
| |
Collapse
|
42
|
Spencer KC, Sy JC, Falcón-Banchs R, Cima MJ. A three dimensional in vitro glial scar model to investigate the local strain effects from micromotion around neural implants. LAB ON A CHIP 2017; 17:795-804. [PMID: 28119969 PMCID: PMC5389738 DOI: 10.1039/c6lc01411a] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Glial scar formation remains a significant barrier to the long term success of neural probes. Micromotion coupled with mechanical mismatch between the probe and tissue is believed to be a key driver of the inflammatory response. In vitro glial scar models present an intermediate step prior to conventional in vivo histology experiments as they enable cell-device interactions to be tested on a shorter timescale, with the ability to conduct broader biochemical assays. No established in vitro models have incorporated methods to assess device performance with respect to mechanical factors. In this study, we describe an in vitro glial scar model that combines high-precision linear actuators to simulate axial micromotion around neural implants with a 3D primary neural cell culture in a collagen gel. Strain field measurements were conducted to visualize the local displacement within the gel in response to micromotion. Primary brain cell cultures were found to be mechanically responsive to micromotion after one week in culture. Astrocytes, as determined by immunohistochemical staining, were found to have significantly increased in cell areas and perimeters in response to micromotion compared to static control wells. These results demonstrate the importance of micromotion when considering the chronic response to neural implants. Going forward, this model provides advantages over existing in vitro models as it will enable critical mechanical design factors of neural implants to be evaluated prior to in vivo testing.
Collapse
Affiliation(s)
- Kevin C Spencer
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
| | - Jay C Sy
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA and Department of Biomedical Engineering, Rutgers University, Piscataway, NJ, USA
| | - Roberto Falcón-Banchs
- University of California, Berkeley and University of California, San Francisco Graduate Program in Bioengineering, USA
| | - Michael J Cima
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA. and Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| |
Collapse
|
43
|
Eles JR, Vazquez AL, Snyder NR, Lagenaur C, Murphy MC, Kozai TDY, Cui XT. Neuroadhesive L1 coating attenuates acute microglial attachment to neural electrodes as revealed by live two-photon microscopy. Biomaterials 2016; 113:279-292. [PMID: 27837661 DOI: 10.1016/j.biomaterials.2016.10.054] [Citation(s) in RCA: 80] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2016] [Revised: 10/26/2016] [Accepted: 10/30/2016] [Indexed: 12/15/2022]
Abstract
Implantable neural electrode technologies for chronic neural recordings can restore functional control to paralysis and limb loss victims through brain-machine interfaces. These probes, however, have high failure rates partly due to the biological responses to the probe which generate an inflammatory scar and subsequent neuronal cell death. L1 is a neuronal specific cell adhesion molecule and has been shown to minimize glial scar formation and promote electrode-neuron integration when covalently attached to the surface of neural probes. In this work, the acute microglial response to L1-coated neural probes was evaluated in vivo by implanting coated devices into the cortex of mice with fluorescently labeled microglia, and tracking microglial dynamics with multi-photon microscopy for the ensuing 6 h in order to understand L1's cellular mechanisms of action. Microglia became activated immediately after implantation, extending processes towards both L1-coated and uncoated control probes at similar velocities. After the processes made contact with the probes, microglial processes expanded to cover 47.7% of the control probes' surfaces. For L1-coated probes, however, there was a statistically significant 83% reduction in microglial surface coverage. This effect was sustained through the experiment. At 6 h post-implant, the radius of microglia activation was reduced for the L1 probes by 20%, shifting from 130.0 to 103.5 μm with the coating. Microglia as far as 270 μm from the implant site displayed significantly lower morphological characteristics of activation for the L1 group. These results suggest that the L1 surface treatment works in an acute setting by microglial mediated mechanisms.
Collapse
Affiliation(s)
- James R Eles
- Bioengineering, University of Pittsburgh, United States; Center for the Neural Basis of Cognition, University of Pittsburgh and Carnegie Mellon University, United States
| | - Alberto L Vazquez
- Bioengineering, University of Pittsburgh, United States; Radiology, University of Pittsburgh, United States; Neurobiology, University of Pittsburgh, United States
| | - Noah R Snyder
- Bioengineering, University of Pittsburgh, United States; Center for the Neural Basis of Cognition, University of Pittsburgh and Carnegie Mellon University, United States
| | - Carl Lagenaur
- Neurobiology, University of Pittsburgh, United States
| | | | - Takashi D Y Kozai
- Bioengineering, University of Pittsburgh, United States; Center for the Neural Basis of Cognition, University of Pittsburgh and Carnegie Mellon University, United States; McGowan Institute for Regenerative Medicine, University of Pittsburgh, United States; NeuroTech Center of the University of Pittsburgh Brain Institute, United States.
| | - X Tracy Cui
- Bioengineering, University of Pittsburgh, United States; Center for the Neural Basis of Cognition, University of Pittsburgh and Carnegie Mellon University, United States; McGowan Institute for Regenerative Medicine, University of Pittsburgh, United States.
| |
Collapse
|
44
|
Khilwani R, Gilgunn PJ, Kozai TDY, Ong XC, Korkmaz E, Gunalan PK, Cui XT, Fedder GK, Ozdoganlar OB. Ultra-miniature ultra-compliant neural probes with dissolvable delivery needles: design, fabrication and characterization. Biomed Microdevices 2016; 18:97. [DOI: 10.1007/s10544-016-0125-4] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
|
45
|
Kozai TDY, Jaquins-Gerstl AS, Vazquez AL, Michael AC, Cui XT. Dexamethasone retrodialysis attenuates microglial response to implanted probes in vivo. Biomaterials 2016; 87:157-169. [PMID: 26923363 PMCID: PMC4866508 DOI: 10.1016/j.biomaterials.2016.02.013] [Citation(s) in RCA: 76] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Revised: 02/04/2016] [Accepted: 02/07/2016] [Indexed: 12/19/2022]
Abstract
Intracortical neural probes enable researchers to measure electrical and chemical signals in the brain. However, penetration injury from probe insertion into living brain tissue leads to an inflammatory tissue response. In turn, microglia are activated, which leads to encapsulation of the probe and release of pro-inflammatory cytokines. This inflammatory tissue response alters the electrical and chemical microenvironment surrounding the implanted probe, which may in turn interfere with signal acquisition. Dexamethasone (Dex), a potent anti-inflammatory steroid, can be used to prevent and diminish tissue disruptions caused by probe implantation. Herein, we report retrodialysis administration of dexamethasone while using in vivo two-photon microscopy to observe real-time microglial reaction to the implanted probe. Microdialysis probes under artificial cerebrospinal fluid (aCSF) perfusion with or without Dex were implanted into the cortex of transgenic mice that express GFP in microglia under the CX3CR1 promoter and imaged for 6 h. Acute morphological changes in microglia were evident around the microdialysis probe. The radius of microglia activation was 177.1 μm with aCSF control compared to 93.0 μm with Dex perfusion. T-stage morphology and microglia directionality indices were also used to quantify the microglial response to implanted probes as a function of distance. Dexamethasone had a profound effect on the microglia morphology and reduced the acute activation of these cells.
Collapse
Affiliation(s)
- Takashi D Y Kozai
- Bioengineering, University of Pittsburgh, United States; Center for the Neural Basis of Cognition, United States; McGowan Institute for Regenerative Medicine, University of Pittsburgh, United States; Neurotech Center of the University of Pittsburgh Brain Institute, United States.
| | | | - Alberto L Vazquez
- Bioengineering, University of Pittsburgh, United States; Center for the Neural Basis of Cognition, United States; Radiology, University of Pittsburgh, United States
| | | | - X Tracy Cui
- Bioengineering, University of Pittsburgh, United States; Center for the Neural Basis of Cognition, United States; McGowan Institute for Regenerative Medicine, University of Pittsburgh, United States.
| |
Collapse
|
46
|
Engineering and commercialization of human-device interfaces, from bone to brain. Biomaterials 2016; 95:35-46. [PMID: 27108404 DOI: 10.1016/j.biomaterials.2016.03.038] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Revised: 03/16/2016] [Accepted: 03/28/2016] [Indexed: 12/16/2022]
Abstract
Cutting edge developments in engineering of tissues, implants and devices allow for guidance and control of specific physiological structure-function relationships. Yet the engineering of functionally appropriate human-device interfaces represents an intractable challenge in the field. This leading opinion review outlines a set of current approaches as well as hurdles to design of interfaces that modulate transfer of information, i.a. forces, electrical potentials, chemical gradients and haptotactic paths, between endogenous and engineered body parts or tissues. The compendium is designed to bridge across currently separated disciplines by highlighting specific commonalities between seemingly disparate systems, e.g. musculoskeletal and nervous systems. We focus on specific examples from our own laboratories, demonstrating that the seemingly disparate musculoskeletal and nervous systems share common paradigms which can be harnessed to inspire innovative interface design solutions. Functional barrier interfaces that control molecular and biophysical traffic between tissue compartments of joints are addressed in an example of the knee. Furthermore, we describe the engineering of gradients for interfaces between endogenous and engineered tissues as well as between electrodes that physically and electrochemically couple the nervous and musculoskeletal systems. Finally, to promote translation of newly developed technologies into products, protocols, and treatments that benefit the patients who need them most, regulatory and technical challenges and opportunities are addressed on hand from an example of an implant cum delivery device that can be used to heal soft and hard tissues, from brain to bone.
Collapse
|
47
|
Prodanov D, Delbeke J. Mechanical and Biological Interactions of Implants with the Brain and Their Impact on Implant Design. Front Neurosci 2016; 10:11. [PMID: 26903786 PMCID: PMC4746296 DOI: 10.3389/fnins.2016.00011] [Citation(s) in RCA: 78] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2015] [Accepted: 01/11/2016] [Indexed: 11/26/2022] Open
Abstract
Neural prostheses have already a long history and yet the cochlear implant remains the only success story about a longterm sensory function restoration. On the other hand, neural implants for deep brain stimulation are gaining acceptance for variety of disorders including Parkinsons disease and obsessive-compulsive disorder. It is anticipated that the progress in the field has been hampered by a combination of technological and biological factors, such as the limited understanding of the longterm behavior of implants, unreliability of devices, biocompatibility of the implants among others. While the field's understanding of the cell biology of interactions at the biotic-abiotic interface has improved, relatively little attention has been paid on the mechanical factors (stress, strain), and hence on the geometry that can modulate it. This focused review summarizes the recent progress in the understanding of the mechanisms of mechanical interaction between the implants and the brain. The review gives an overview of the factors by which the implants interact acutely and chronically with the tissue: blood-brain barrier (BBB) breach, vascular damage, micromotions, diffusion etc. We propose some design constraints to be considered in future studies. Aspects of the chronic cell-implant interaction will be discussed in view of the chronic local inflammation and the ways of modulating it.
Collapse
Affiliation(s)
- Dimiter Prodanov
- Department of Environment, Health and Safety, ImecLeuven, Belgium
- Neuroscience Research FlandersLeuven, Belgium
| | - Jean Delbeke
- LCEN3, Department of Neurology, Institute of Neuroscience, Ghent UniversityGhent, Belgium
| |
Collapse
|
48
|
Lv Z, Fan J, Zhang X, Huang Q, Han J, Wu F, Hu G, Guo M, Jin Y. Integrative genomic analysis of interleukin-36RN and its prognostic value in cancer. Mol Med Rep 2015; 13:1404-12. [PMID: 26676204 DOI: 10.3892/mmr.2015.4667] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2015] [Accepted: 10/28/2015] [Indexed: 11/05/2022] Open
Abstract
Interleukin (IL)-36RN, previously known as IL1-F5 and IL-1δ, shares a 360-kb region of chromosome 2q13 with members of IL-1 systems. IL-36RN encodes an anti-inflammatory cytokine, IL-36 receptor antagonist (IL-36Ra). In spite of IL-36Ra showing the highest homology to IL-1 receptor (IL-1R) antagonist, it differs from the latter in aspects including its binding to IL-lRrp2 but not to IL-1R1. IL-36RN is mainly expressed in epithelial cells and has important roles in inflammatory diseases. In the present study, IL-36RN was identified in the genomes of 27 species, including human, chimpanzee, mouse, horse and dolphin. Human IL-36RN was mainly expressed in the eye, head and neck, fetal heart, lung, testis, cervix and placenta; furthermore, it was highly expressed in bladder and parathyroid tumors. Furthermore, a total of 30 single nucleotide polymorphisms causing missense mutations were determined, which are considered to be the causes of various diseases, such as generalized pustular psoriasis. In addition, the link between IL-36RN and the prognosis of certain cancer types was revealed through meta-analysis. Tumor-associated transcriptional factors c-Fos, activator protein-1, c-Jun and nuclear factor κB were found to bind to the upstream region in the IL-36RN gene. This may indicate that IL-36RN is involved in tumorigenesis and tumor progression through the regulation of tumor-associated transcriptional factors. The present study identified IL-36RN in various species and investigated the associations between IL-36RN and cancer prognosis, which would determine whether IL-36RN drove the evolution of the various species with regard to tumorigenesis.
Collapse
Affiliation(s)
- Zhilei Lv
- Department of Respiratory and Critical Care Medicine, Key Laboratory of Pulmonary Diseases of the Ministry of Health, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430022, P.R. China
| | - Jinshuo Fan
- Department of Respiratory and Critical Care Medicine, Key Laboratory of Pulmonary Diseases of the Ministry of Health, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430022, P.R. China
| | - Xiuxiu Zhang
- Department of Respiratory and Critical Care Medicine, Key Laboratory of Pulmonary Diseases of the Ministry of Health, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430022, P.R. China
| | - Qi Huang
- Department of Respiratory and Critical Care Medicine, Key Laboratory of Pulmonary Diseases of the Ministry of Health, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430022, P.R. China
| | - Jieli Han
- Department of Respiratory and Critical Care Medicine, Key Laboratory of Pulmonary Diseases of the Ministry of Health, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430022, P.R. China
| | - Feng Wu
- Department of Respiratory and Critical Care Medicine, Key Laboratory of Pulmonary Diseases of the Ministry of Health, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430022, P.R. China
| | - Guorong Hu
- Department of Respiratory and Critical Care Medicine, Key Laboratory of Pulmonary Diseases of the Ministry of Health, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430022, P.R. China
| | - Mengfei Guo
- Department of Respiratory and Critical Care Medicine, Key Laboratory of Pulmonary Diseases of the Ministry of Health, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430022, P.R. China
| | - Yang Jin
- Department of Respiratory and Critical Care Medicine, Key Laboratory of Pulmonary Diseases of the Ministry of Health, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430022, P.R. China
| |
Collapse
|
49
|
Two-photon imaging of chronically implanted neural electrodes: Sealing methods and new insights. J Neurosci Methods 2015; 258:46-55. [PMID: 26526459 DOI: 10.1016/j.jneumeth.2015.10.007] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Revised: 10/12/2015] [Accepted: 10/15/2015] [Indexed: 01/03/2023]
Abstract
BACKGROUND Two-photon microscopy has enabled the visualization of dynamic tissue changes to injury and disease in vivo. While this technique has provided powerful new information, in vivo two-photon chronic imaging around tethered cortical implants, such as microelectrodes or neural probes, present unique challenges. NEW METHOD A number of strategies are described to prepare a cranial window to longitudinally observe the impact of neural probes on brain tissue and vasculature for up to 3 months. RESULTS It was found that silastic sealants limit cell infiltration into the craniotomy, thereby limiting light scattering and preserving window clarity over time. In contrast, low concentration hydrogel sealants failed to prevent cell infiltration and their use at high concentration displaced brain tissue and disrupted probe performance. COMPARISON WITH EXISTING METHOD(S) The use of silastic sealants allows for a suitable imaging window for long term chronic experiments and revealed new insights regarding the dynamic leukocyte response around implants and the nature of chronic BBB leakage in the sub-dural space. CONCLUSION The presented method provides a valuable tool for evaluating the chronic inflammatory response and the performance of emerging implantable neural technologies.
Collapse
|
50
|
Acton D, Miles GB. Stimulation of Glia Reveals Modulation of Mammalian Spinal Motor Networks by Adenosine. PLoS One 2015; 10:e0134488. [PMID: 26252389 PMCID: PMC4529192 DOI: 10.1371/journal.pone.0134488] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2015] [Accepted: 07/09/2015] [Indexed: 01/05/2023] Open
Abstract
Despite considerable evidence that glia can release modulators to influence the excitability of neighbouring neurons, the importance of gliotransmission for the operation of neural networks and in shaping behaviour remains controversial. Here we characterise the contribution of glia to the modulation of the mammalian spinal central pattern generator for locomotion, the output of which is directly relatable to a defined behaviour. Glia were stimulated by specific activation of protease-activated receptor-1 (PAR1), an endogenous G-protein coupled receptor preferentially expressed by spinal glia during ongoing activity of the spinal central pattern generator for locomotion. Selective activation of PAR1 by the agonist TFLLR resulted in a reversible reduction in the frequency of locomotor-related bursting recorded from ventral roots of spinal cord preparations isolated from neonatal mice. In the presence of the gliotoxins methionine sulfoximine or fluoroacetate, TFLLR had no effect, confirming the specificity of PAR1 activation to glia. The modulation of burst frequency upon PAR1 activation was blocked by the non-selective adenosine-receptor antagonist theophylline and by the A1-receptor antagonist 8-cyclopentyl-1,3-dipropylxanthine, but not by the A2A-receptor antagonist SCH5826, indicating production of extracellular adenosine upon glial stimulation, followed by A1-receptor mediated inhibition of neuronal activity. Modulation of network output following glial stimulation was also blocked by the ectonucleotidase inhibitor ARL67156, indicating glial release of ATP and its subsequent degradation to adenosine rather than direct release of adenosine. Glial stimulation had no effect on rhythmic activity recorded following blockade of inhibitory transmission, suggesting that glial cell-derived adenosine acts via inhibitory circuit components to modulate locomotor-related output. Finally, the modulation of network output by endogenous adenosine was found to scale with the frequency of network activity, implying activity-dependent release of adenosine. Together, these data indicate that glia play an active role in the modulation of mammalian locomotor networks, providing negative feedback control that may stabilise network activity.
Collapse
Affiliation(s)
- David Acton
- School of Psychology and Neuroscience, University of St Andrews, Fife, United Kingdom
| | - Gareth B. Miles
- School of Psychology and Neuroscience, University of St Andrews, Fife, United Kingdom
- * E-mail:
| |
Collapse
|