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Shi D, Narayanan S, Woeppel K, Cui XT. Improving the Biocompatibility and Functionality of Neural Interface Devices with Silica Nanoparticles. Acc Chem Res 2024; 57:1684-1695. [PMID: 38814586 PMCID: PMC11191400 DOI: 10.1021/acs.accounts.4c00160] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2024] [Revised: 05/03/2024] [Accepted: 05/17/2024] [Indexed: 05/31/2024]
Abstract
ConspectusNeural interface technologies enable bidirectional communication between the nervous system and external instrumentation. Advancements in neural interface devices not only open new frontiers for neuroscience research, but also hold great promise for clinical diagnosis, therapy, and rehabilitation for various neurological disorders. However, the performance of current neural electrode devices, often termed neural probes, is far from satisfactory. Glial scarring, neuronal degeneration, and electrode degradation eventually cause the devices to lose their connection with the brain. To improve the chronic performance of neural probes, efforts need to be made on two fronts: enhancing the physiochemical properties of the electrode materials and mitigating the undesired host tissue response.In this Account, we discuss our efforts in developing silica-nanoparticle-based (SiNP) coatings aimed at enhancing neural probe electrochemical properties and promoting device-tissue integration. Our work focuses on three approaches:(1) SiNPs' surface texturization to enhance biomimetic protein coatings for promoting neural integration. Through covalent immobilization, SiNP introduces biologically relevant nanotopography to neural probe surfaces, enhancing neuronal cell attachments and inhibiting microglia. The SiNP base coating further increases the binding density and stability of bioactive molecules such as L1CAM and facilitates the widespread dissemination of biomimetic coatings. (2) Doping SiNPs into conductive polymer electrode coatings improves the electrochemical properties and stability. As neural interface devices are moving to subcellular sizes to escape the immune response and high electrode site density to increase spatial resolution, the electrode sites need to be very small. The smaller electrode size comes at the cost of a high electrode impedance, elevated thermal noise, and insufficient charge injection capacity. Electrochemically deposited conductive polymer films reduce electrode impedance but do not endure prolonged electrical cycling. When incorporated into conductive polymer coatings as a dopant, the SiNP provides structural support for the polymer thin films, significantly increasing their stability and durability. Low interfacial impedance maintained by the conducting polymer/SiNP composite is critical for extended electrode longevity and effective charge injection in chronic neural stimulation applications. (3) Porous nanoparticles are used as drug carriers in conductive polymer coatings for local drug/neurochemical delivery. When triggered by external electrical stimuli, drug molecules and neurochemicals can be released in a controlled manner. Such precise focal manipulation of cellular and vascular behavior enables us to probe brain circuitry and develop therapeutic applications.We foresee tremendous opportunities for further advancing the functionality of SiNP coatings by incorporating new nanoscale components and integrating the coating with other design strategies. With an enriched nanoscale toolbox and optimized design strategies, we can create customizable multifunctional and multimodal neural interfaces that can operate at multiple spatial levels and seamlessly integrate with the host tissue for extended applications.
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Affiliation(s)
- Delin Shi
- University
of Pittsburgh, Department of Bioengineering, 4200 Fifth Avenue, Pittsburgh, Pennsylvania 15260, United States
- Center
for the Neural Basis of Cognition, 4400 Fifth Avenue, Suite 115, Pittsburgh, Pennsylvania 15213, United States
| | - Sharada Narayanan
- University
of Pittsburgh, Department of Bioengineering, 4200 Fifth Avenue, Pittsburgh, Pennsylvania 15260, United States
- Center
for the Neural Basis of Cognition, 4400 Fifth Avenue, Suite 115, Pittsburgh, Pennsylvania 15213, United States
| | - Kevin Woeppel
- University
of Pittsburgh, Department of Bioengineering, 4200 Fifth Avenue, Pittsburgh, Pennsylvania 15260, United States
- Center
for the Neural Basis of Cognition, 4400 Fifth Avenue, Suite 115, Pittsburgh, Pennsylvania 15213, United States
| | - Xinyan Tracy Cui
- University
of Pittsburgh, Department of Bioengineering, 4200 Fifth Avenue, Pittsburgh, Pennsylvania 15260, United States
- Center
for the Neural Basis of Cognition, 4400 Fifth Avenue, Suite 115, Pittsburgh, Pennsylvania 15213, United States
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2
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Aktas B, Ozgun A, Kilickap BD, Garipcan B. Cell adhesion molecule immobilized gold surfaces for enhanced neuron-electrode interfaces. J Biomed Mater Res B Appl Biomater 2024; 112:e35310. [PMID: 37950592 DOI: 10.1002/jbm.b.35310] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Revised: 06/24/2023] [Accepted: 07/31/2023] [Indexed: 11/12/2023]
Abstract
To provide a long-term solution for increasing the biocompatibility of neuroprosthetics, approaches to reduce the side effects of invasive neuro-implantable devices are still in need of improvement. Physical, chemical, and bioactive design aspects of the biomaterials are proven to be important for providing proper cell-to-cell, cell-to-material interactions. Particularly, modification of implant surfaces with bioactive cues, especially cell adhesion molecules (CAMs) that capitalize on native neural adhesion mechanisms, are promising candidates in favor of providing efficient interfaces. Within this concept, this study utilized specific CAMs, namely N-Cadherin (Neural cadherin, N-Cad) and neural cell adhesion molecule (NCAM), to enhance neuron-electrode contact by mimicking the cell-to-ECM interactions for improving the survival of cells and promoting neurite outgrowth. For this purpose, representative gold electrode surfaces were modified with N-Cadherin, NCAM, and the mixture (1:1) of these molecules. Modifications were characterized, and the effect of surface modification on both differentiated and undifferentiated neuroblastoma SH-SY5Y cell lines were compared. The findings demonstrated the successful modification of these molecules which subsequently exhibited biocompatible properties as evidenced by the cell viability results. In cell culture experiments, the CAMs displayed promising results in promoting neurite outgrowth compared to conventional poly-l-lysine coated surfaces, especially NCAM and N-Cad/NCAM modified surfaces clearly showed significant improvement. Overall, this optimized approach is expected to provide an insight into the action mechanisms of cells against the local environment and advance processes for the fabrication of alternative neural interfaces.
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Affiliation(s)
- Bengu Aktas
- Institute of Biomedical Engineering, Bogazici University, Istanbul, Turkey
| | - Alp Ozgun
- Department of Mechanical Engineering, Faculty of Engineering, University of Ottawa, Ottawa, Ontario, Canada
- Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada
| | | | - Bora Garipcan
- Institute of Biomedical Engineering, Bogazici University, Istanbul, Turkey
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3
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Woeppel K, Dhawan V, Shi D, Cui XT. Nanotopography-enhanced biomimetic coating maintains bioactivity after weeks of dry storage and improves chronic neural recording. Biomaterials 2023; 302:122326. [PMID: 37716282 PMCID: PMC10993103 DOI: 10.1016/j.biomaterials.2023.122326] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2023] [Revised: 09/01/2023] [Accepted: 09/11/2023] [Indexed: 09/18/2023]
Abstract
We developed a nanoparticle base layer technology capable of maintaining the bioactivity of protein-based neural probe coating intended to improve neural recording quality. When covalently bound on thiolated nanoparticle (TNP) modified surfaces, neural adhesion molecule L1 maintained bioactivity throughout 8 weeks of dry storage at room temperature, while those bound to unmodified surfaces lost 66% bioactivity within 3 days. We tested the TNP + L1 coating in mouse brains on two different neural electrode arrays after two different dry storage durations (3 and 28 days). The results show that dry-stored coating is as good as the freshly prepared, and even after 28 days of storage, the number of single units per channel and signal-to-noise ratio of the TNP + L1 coated arrays were significantly higher by 32% and 40% respectively than uncoated controls over 16 weeks. This nanoparticle base layer approach enables the dissemination of biomolecule-functionalized neural probes to users worldwide and may also benefit a broad range of applications that rely on surface-bound biomolecules.
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Affiliation(s)
- Kevin Woeppel
- University of Pittsburgh, Department of Bioengineering, 4200 Fifth Avenue, Pittsburgh, PA, 15260, USA; Center for the Neural Basis of Cognition, 4400 Fifth Avenue, Suite 115, Pittsburgh, PA, 15213, USA
| | - Vaishnavi Dhawan
- University of Pittsburgh, Department of Bioengineering, 4200 Fifth Avenue, Pittsburgh, PA, 15260, USA; Center for the Neural Basis of Cognition, 4400 Fifth Avenue, Suite 115, Pittsburgh, PA, 15213, USA
| | - Delin Shi
- University of Pittsburgh, Department of Bioengineering, 4200 Fifth Avenue, Pittsburgh, PA, 15260, USA; Center for the Neural Basis of Cognition, 4400 Fifth Avenue, Suite 115, Pittsburgh, PA, 15213, USA
| | - Xinyan Tracy Cui
- University of Pittsburgh, Department of Bioengineering, 4200 Fifth Avenue, Pittsburgh, PA, 15260, USA; Center for the Neural Basis of Cognition, 4400 Fifth Avenue, Suite 115, Pittsburgh, PA, 15213, USA; McGowan Institute for Regenerative Medicine, 450 Technology Drive, Suite 300, Pittsburgh, PA, 15219, USA.
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4
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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.
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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
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5
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Ahnood A, Chambers A, Gelmi A, Yong KT, Kavehei O. Semiconducting electrodes for neural interfacing: a review. Chem Soc Rev 2023; 52:1491-1518. [PMID: 36734845 DOI: 10.1039/d2cs00830k] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
In the past 50 years, the advent of electronic technology to directly interface with neural tissue has transformed the fields of medicine and biology. Devices that restore or even replace impaired bodily functions, such as deep brain stimulators and cochlear implants, have ushered in a new treatment era for previously intractable conditions. Meanwhile, electrodes for recording and stimulating neural activity have allowed researchers to unravel the vast complexities of the human nervous system. Recent advances in semiconducting materials have allowed effective interfaces between electrodes and neuronal tissue through novel devices and structures. Often these are unattainable using conventional metallic electrodes. These have translated into advances in research and treatment. The development of semiconducting materials opens new avenues in neural interfacing. This review considers this emerging class of electrodes and how it can facilitate electrical, optical, and chemical sensing and modulation with high spatial and temporal precision. Semiconducting electrodes have advanced electrically based neural interfacing technologies owing to their unique electrochemical and photo-electrochemical attributes. Key operation modalities, namely sensing and stimulation in electrical, biochemical, and optical domains, are discussed, highlighting their contrast to metallic electrodes from the application and characterization perspective.
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Affiliation(s)
- Arman Ahnood
- School of Engineering, RMIT University, VIC 3000, Australia
| | - Andre Chambers
- School of Physics, University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Amy Gelmi
- School of Science, RMIT University, VIC 3000, Australia
| | - Ken-Tye Yong
- School of Biomedical Engineering, University of Sydney, Sydney, NSW 2006, Australia.,The University of Sydney Nano Institute, Sydney, NSW 2006, Australia.
| | - Omid Kavehei
- School of Biomedical Engineering, University of Sydney, Sydney, NSW 2006, Australia.,The University of Sydney Nano Institute, Sydney, NSW 2006, Australia.
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6
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Alavarse AC, Frachini ECG, Silva JB, Pereira RDS, Ulrich H, Petri DFS. Amino acid decorated xanthan gum coatings: Molecular arrangement and cell adhesion. CARBOHYDRATE POLYMER TECHNOLOGIES AND APPLICATIONS 2022. [DOI: 10.1016/j.carpta.2022.100227] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
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7
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Dhawan V, Cui XT. Carbohydrate based biomaterials for neural interface applications. J Mater Chem B 2022; 10:4714-4740. [PMID: 35702979 DOI: 10.1039/d2tb00584k] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Neuroprosthetic devices that record and modulate neural activities have demonstrated immense potential for bypassing or restoring lost neurological functions due to neural injuries and disorders. However, implantable electrical devices interfacing with brain tissue are susceptible to a series of inflammatory tissue responses along with mechanical or electrical failures which can affect the device performance over time. Several biomaterial strategies have been implemented to improve device-tissue integration for high quality and stable performance. Ranging from developing smaller, softer, and more flexible electrode designs to introducing bioactive coatings and drug-eluting layers on the electrode surface, such strategies have shown different degrees of success but with limitations. With their hydrophilic properties and specific bioactivities, carbohydrates offer a potential solution for addressing some of the limitations of the existing biomolecular approaches. In this review, we summarize the role of polysaccharides in the central nervous system, with a primary focus on glycoproteins and proteoglycans, to shed light on their untapped potential as biomaterials for neural implants. Utilization of glycosaminoglycans for neural interface and tissue regeneration applications is comprehensively reviewed to provide the current state of carbohydrate-based biomaterials for neural implants. Finally, we will discuss the challenges and opportunities of applying carbohydrate-based biomaterials for neural tissue interfaces.
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Affiliation(s)
- Vaishnavi Dhawan
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA. .,Center for Neural Basis of Cognition, Pittsburgh, PA, USA
| | - Xinyan Tracy Cui
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA. .,Center for Neural Basis of Cognition, Pittsburgh, PA, USA.,McGowan Institute for Regenerative Medicine, Pittsburgh, PA, USA
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8
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Ding R, Miller NC, Woeppel KM, Cui XT, Jacobs TDB. Surface Area and Local Curvature: Why Roughness Improves the Bioactivity of Neural Implants. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2022; 38:7512-7521. [PMID: 35678760 PMCID: PMC10080668 DOI: 10.1021/acs.langmuir.2c00473] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
While roughening the surface of neural implants has been shown to significantly improve their performance, the mechanism for this improvement is not understood, preventing systematic optimization of surfaces. Specifically, prior work has shown that the cellular response to a surface can be significantly enhanced by coating the implant surface with inorganic nanoparticles and neuroadhesion protein L1, and this improvement occurs even when the surface chemistry is identical between the nanoparticle-coated and uncoated electrodes, suggesting the critical importance of surface topography. Here, we use transmission electron microscopy to characterize the topography of bare and nanoparticle-coated implants across 7 orders of magnitude in size, from the device scale to the atomic scale. The results reveal multiscale roughness, which cannot be adequately described using conventional roughness parameters. Indeed, the topography is nearly identical between the two samples at the smallest scales and also at the largest scales but vastly different in the intermediate scales, especially in the range of 5-100 nm. Using a multiscale topography analysis, we show that the coating causes a 76% increase in the available surface area for contact and an order-of-magnitude increase in local surface curvature at characteristic sizes corresponding to specific biological structures. These are correlated with a 75% increase in bound proteins on the surface and a 134% increase in neurite outgrowth. The present investigation presents a framework for analyzing the scale-dependent topography of medical device-relevant surfaces, and suggests the most critical size scales that determine the biological response to implanted materials.
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Affiliation(s)
- Ruikang Ding
- Mechanical Engineering & Materials Science, University of Pittsburgh, 3700 O'Hara St., Benedum Hall Room 636, Pittsburgh, Pennsylvania 15261, United States
| | - Nathaniel C Miller
- Mechanical Engineering & Materials Science, University of Pittsburgh, 3700 O'Hara St., Benedum Hall Room 636, Pittsburgh, Pennsylvania 15261, United States
| | - Kevin M Woeppel
- Bioengineering, University of Pittsburgh, 5057 Biomedical Science Tower 3, 3501 Fifth Ave, Pittsburgh, Pennsylvania 15260, United States
- Center for the Neural Basis of Cognition, 4400 Fifth Ave, Suite 115, Pittsburgh, Pennsylvania 15213, United States
| | - Xinyan T Cui
- Bioengineering, University of Pittsburgh, 5057 Biomedical Science Tower 3, 3501 Fifth Ave, Pittsburgh, Pennsylvania 15260, United States
- Center for the Neural Basis of Cognition, 4400 Fifth Ave, Suite 115, Pittsburgh, Pennsylvania 15213, United States
- McGowan Institute for Regenerative Medicine, Pittsburgh, Pennsylvania 15213, United States
| | - Tevis D B Jacobs
- Mechanical Engineering & Materials Science, University of Pittsburgh, 3700 O'Hara St., Benedum Hall Room 636, Pittsburgh, Pennsylvania 15261, United States
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9
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Bierman-Duquette RD, Safarians G, Huang J, Rajput B, Chen JY, Wang ZZ, Seidlits SK. Engineering Tissues of the Central Nervous System: Interfacing Conductive Biomaterials with Neural Stem/Progenitor Cells. Adv Healthc Mater 2022; 11:e2101577. [PMID: 34808031 PMCID: PMC8986557 DOI: 10.1002/adhm.202101577] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 10/31/2021] [Indexed: 12/19/2022]
Abstract
Conductive biomaterials provide an important control for engineering neural tissues, where electrical stimulation can potentially direct neural stem/progenitor cell (NS/PC) maturation into functional neuronal networks. It is anticipated that stem cell-based therapies to repair damaged central nervous system (CNS) tissues and ex vivo, "tissue chip" models of the CNS and its pathologies will each benefit from the development of biocompatible, biodegradable, and conductive biomaterials. Here, technological advances in conductive biomaterials are reviewed over the past two decades that may facilitate the development of engineered tissues with integrated physiological and electrical functionalities. First, one briefly introduces NS/PCs of the CNS. Then, the significance of incorporating microenvironmental cues, to which NS/PCs are naturally programmed to respond, into biomaterial scaffolds is discussed with a focus on electrical cues. Next, practical design considerations for conductive biomaterials are discussed followed by a review of studies evaluating how conductive biomaterials can be engineered to control NS/PC behavior by mimicking specific functionalities in the CNS microenvironment. Finally, steps researchers can take to move NS/PC-interfacing, conductive materials closer to clinical translation are discussed.
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Affiliation(s)
| | - Gevick Safarians
- Department of Bioengineering, University of California Los Angeles, USA
| | - Joyce Huang
- Department of Bioengineering, University of California Los Angeles, USA
| | - Bushra Rajput
- Department of Bioengineering, University of California Los Angeles, USA
| | - Jessica Y. Chen
- Department of Bioengineering, University of California Los Angeles, USA
- David Geffen School of Medicine, University of California Los Angeles, USA
| | - Ze Zhong Wang
- Department of Bioengineering, University of California Los Angeles, USA
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10
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Zhuang Y, Xie RJ. Mechanoluminescence Rebrightening the Prospects of Stress Sensing: A Review. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2021; 33:e2005925. [PMID: 33786872 DOI: 10.1002/adma.202005925] [Citation(s) in RCA: 65] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 12/28/2020] [Indexed: 06/12/2023]
Abstract
The emergence of new applications, such as in artificial intelligence, the internet of things, and biotechnology, has driven the evolution of stress sensing technology. For these emerging applications, stretchability, remoteness, stress distribution, a multimodal nature, and biocompatibility are important performance characteristics of stress sensors. Mechanoluminescence (ML)-based stress sensing has attracted widespread attention because of its characteristics of remoteness and having a distributed response to mechanical stimuli as well as its great potential for stretchability, biocompatibility, and self-powering. In the past few decades, great progress has been made in the discovery of ML materials, analysis of mechanisms, design of devices, and exploration of applications. One can find that with this progress, the focus of ML research has shifted from the phenomenon in the earliest stage to materials and recently toward devices. At the present stage, while showing great prospects for advanced stress sensing applications, ML-based sensing still faces major challenges in material optimization, device design, and system integration.
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Affiliation(s)
- Yixi Zhuang
- College of Materials and Fujian Provincial Key Laboratory of Materials Genome, Xiamen University, Xiamen, 361005, China
| | - Rong-Jun Xie
- College of Materials and Fujian Provincial Key Laboratory of Materials Genome, Xiamen University, Xiamen, 361005, China
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11
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Stangler LA, Kouzani A, Bennet KE, Dumee L, Berk M, Worrell GA, Steele S, Burns TC, Howe CL. Microdialysis and microperfusion electrodes in neurologic disease monitoring. Fluids Barriers CNS 2021; 18:52. [PMID: 34852829 PMCID: PMC8638547 DOI: 10.1186/s12987-021-00292-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Accepted: 11/23/2021] [Indexed: 11/10/2022] Open
Abstract
Contemporary biomarker collection techniques in blood and cerebrospinal fluid have to date offered only modest clinical insights into neurologic diseases such as epilepsy and glioma. Conversely, the collection of human electroencephalography (EEG) data has long been the standard of care in these patients, enabling individualized insights for therapy and revealing fundamental principles of human neurophysiology. Increasing interest exists in simultaneously measuring neurochemical biomarkers and electrophysiological data to enhance our understanding of human disease mechanisms. This review compares microdialysis, microperfusion, and implanted EEG probe architectures and performance parameters. Invasive consequences of probe implantation are also investigated along with the functional impact of biofouling. Finally, previously developed microdialysis electrodes and microperfusion electrodes are reviewed in preclinical and clinical settings. Critically, current and precedent microdialysis and microperfusion probes lack the ability to collect neurochemical data that is spatially and temporally coincident with EEG data derived from depth electrodes. This ultimately limits diagnostic and therapeutic progress in epilepsy and glioma research. However, this gap also provides a unique opportunity to create a dual-sensing technology that will provide unprecedented insights into the pathogenic mechanisms of human neurologic disease.
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Affiliation(s)
- Luke A Stangler
- School of Engineering, Deakin University, 3216, Geelong, Victoria, Australia
- Division of Engineering, Mayo Clinic, 55905, Rochester, MN, USA
| | - Abbas Kouzani
- School of Engineering, Deakin University, 3216, Geelong, Victoria, Australia
| | - Kevin E Bennet
- School of Engineering, Deakin University, 3216, Geelong, Victoria, Australia
- Division of Engineering, Mayo Clinic, 55905, Rochester, MN, USA
| | - Ludovic Dumee
- School of Engineering, Deakin University, 3216, Geelong, Victoria, Australia
| | - Michael Berk
- School of Medicine, Deakin University, 3216, Geelong, Victoria, Australia
| | | | - Steven Steele
- Division of Engineering, Mayo Clinic, 55905, Rochester, MN, USA
| | - Terence C Burns
- Department of Neurosurgery, Mayo Clinic, 55905, Rochester, MN, USA
| | - Charles L Howe
- Department of Neurology, Mayo Clinic, 55905, Rochester, MN, USA.
- Division of Experimental Neurology, Mayo Clinic, 55905, Rochester, MN, USA.
- Center for MS and Autoimmune Neurology, Mayo Clinic, 55905, Rochester, MN, USA.
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12
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Kim D, Park D, Kim TH, Chung JJ, Jung Y, Kim SH. Substance P/Heparin-Conjugated PLCL Mitigate Acute Gliosis on Neural Implants and Improve Neuronal Regeneration via Recruitment of Neural Stem Cells. Adv Healthc Mater 2021; 10:e2100107. [PMID: 34227258 DOI: 10.1002/adhm.202100107] [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: 01/18/2021] [Revised: 05/03/2021] [Indexed: 12/15/2022]
Abstract
The inflammatory host tissue response, characterized by gliosis and neuronal death at the neural interface, limits signal transmission and longevity of the neural probe. Substance P induces an anti-inflammatory response and neuronal regeneration and recruits endogenous stem cells. Heparin prevents nonspecific protein adsorption, suppresses the inflammatory response, and is beneficial to neuronal behavior. Poly(l-lactide-co-ε-caprolactone) (PLCL) is a soft and flexible polymer, and PLCL covalently conjugated with biomolecules has been widely used in tissue engineering. Coatings of heparin-conjugated PLCL (Hep-PLCL), substance P-conjugated PLCL (SP-PLCL), and heparin/substance P-conjugated PLCL (Hep/SP-PLCL) reduced the adhesion of astrocytes and fibroblasts and improved neuronal adhesion and neurite development compared to bare glass. The effects of these coatings are evaluated using immunohistochemistry analysis after implantation of coated stainless steel probes in rat brain for 1 week. In particular, Hep/SP-PLCL coating reduced the activation of microglia and astrocytes, the neuronal degeneration caused by inflammation, and indicated a potential for neuronal regeneration at the tissue-device interface. Suppression of the acute host tissue response by coating Hep/SP-PLCL could lead to improved functionality of the neural prosthesis.
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Affiliation(s)
- Donghak Kim
- KU‐KIST Graduate School of Converging Science and Technology Korea University 145 Anam‐ro, Seongbuk‐gu Seoul 02841 Republic of Korea
- Biomaterials Research Center Korea Institute of Science and Technology (KIST) 5, Hwarang‐ro 14‐gil, Seongbuk‐gu Seoul 02792 Republic of Korea
| | - DoYeun Park
- Biomaterials Research Center Korea Institute of Science and Technology (KIST) 5, Hwarang‐ro 14‐gil, Seongbuk‐gu Seoul 02792 Republic of Korea
| | - Tae Hee Kim
- Biomaterials Research Center Korea Institute of Science and Technology (KIST) 5, Hwarang‐ro 14‐gil, Seongbuk‐gu Seoul 02792 Republic of Korea
| | - Justin J. Chung
- Biomaterials Research Center Korea Institute of Science and Technology (KIST) 5, Hwarang‐ro 14‐gil, Seongbuk‐gu Seoul 02792 Republic of Korea
| | - Youngmee Jung
- Biomaterials Research Center Korea Institute of Science and Technology (KIST) 5, Hwarang‐ro 14‐gil, Seongbuk‐gu Seoul 02792 Republic of Korea
| | - Soo Hyun Kim
- KU‐KIST Graduate School of Converging Science and Technology Korea University 145 Anam‐ro, Seongbuk‐gu Seoul 02841 Republic of Korea
- Biomaterials Research Center Korea Institute of Science and Technology (KIST) 5, Hwarang‐ro 14‐gil, Seongbuk‐gu Seoul 02792 Republic of Korea
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13
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Lee Y, Shin H, Lee D, Choi S, Cho I, Seo J. A Lubricated Nonimmunogenic Neural Probe for Acute Insertion Trauma Minimization and Long-Term Signal Recording. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2021; 8:e2100231. [PMID: 34085402 PMCID: PMC8336494 DOI: 10.1002/advs.202100231] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Revised: 03/29/2021] [Indexed: 05/06/2023]
Abstract
Brain-machine interfaces (BMIs) that link the brain to a machine are promising for the treatment of neurological disorders through the bi-directional translation of neural information over extended periods. However, the longevity of such implanted devices remains limited by the deterioration of their signal sensitivity over time due to acute inflammation from insertion trauma and chronic inflammation caused by the foreign body reaction. To address this challenge, a lubricated surface is fabricated to minimize friction during insertion and avoid immunogenicity during neural signal recording. Reduced friction force leads to 86% less impulse on the brain tissue, and thus immediately increases the number of measured signal electrodes by 102% upon insertion. Furthermore, the signal measurable period increases from 8 to 16 weeks due to the prevention of gliosis. By significantly reducing insertion damage and the foreign body reaction, the lubricated immune-stealthy probe surface (LIPS) can maximize the longevity of implantable BMIs.
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Affiliation(s)
- Yeontaek Lee
- School of Electrical and Electronic EngineeringYonsei UniversitySeoul03722Republic of Korea
| | - Hyogeun Shin
- Center for BioMicrosystemsBrain Science InstituteKorea Institute of Science and Technology (KIST)Seoul02792Republic of Korea
- Division of Bio‐Medical Science & Technology, KIST SchoolKorea University of Science and Technology (UST)Seoul02792Republic of Korea
| | - Dongwon Lee
- School of Electrical and Electronic EngineeringYonsei UniversitySeoul03722Republic of Korea
| | - Sungah Choi
- School of Electrical and Electronic EngineeringYonsei UniversitySeoul03722Republic of Korea
| | - Il‐Joo Cho
- School of Electrical and Electronic EngineeringYonsei UniversitySeoul03722Republic of Korea
- Center for BioMicrosystemsBrain Science InstituteKorea Institute of Science and Technology (KIST)Seoul02792Republic of Korea
- Division of Bio‐Medical Science & Technology, KIST SchoolKorea University of Science and Technology (UST)Seoul02792Republic of Korea
- Yonsei‐KIST Convergence Research InstituteYonsei UniversitySeoul03722Republic of Korea
| | - Jungmok Seo
- School of Electrical and Electronic EngineeringYonsei UniversitySeoul03722Republic of Korea
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14
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Woeppel KM, Cui XT. Nanoparticle and Biomolecule Surface Modification Synergistically Increases Neural Electrode Recording Yield and Minimizes Inflammatory Host Response. Adv Healthc Mater 2021; 10:e2002150. [PMID: 34190425 DOI: 10.1002/adhm.202002150] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Revised: 06/08/2021] [Indexed: 11/08/2022]
Abstract
Due to their ability to interface with neural tissues, neural electrodes are the key tool used for neurophysiological studies, electrochemical detection, brain computer interfacing, and countless neuromodulation therapies and diagnostic procedures. However, the long-term applications of neural electrodes are limited by the inflammatory host tissue response, decreasing detectable electrical signals, and insulating the device from the native environment. Surface modification methods are proposed to limit these detrimental responses but each has their own limitations. Here, a combinatorial approach is presented toward creating a stable interface between the electrode and host tissues. First, a thiolated nanoparticle (TNP) coating is utilized to increase the surface area and roughness. Next, the neural adhesion molecule L1 is immobilized to the nanoparticle modified substrate. In vitro, the combined nanotopographical and bioactive modifications (TNP+L1) elevate the bioactivity of L1, which is maintained for 28 d. In vivo, TNP+L1 modification improves the recording performance of the neural electrode arrays compared to TNP or L1 modification alone. Postmortem histology reveals greater neural cell density around the TNP+L1 coating while eliminating any inflammatory microglial encapsulation after 4 weeks. These results demonstrate that nanotopographical and bioactive modifications synergistically produce a seamless neural tissue interface for chronic neural implants.
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Affiliation(s)
- Kevin M. Woeppel
- Department of Bioengineering University of Pittsburgh Pittsburgh PA 15260 USA
- Center for the Neural basis of Cognition Pittsburgh PA 15260 USA
| | - Xinyan Tracy Cui
- Department of Bioengineering University of Pittsburgh Pittsburgh PA 15260 USA
- Center for the Neural basis of Cognition Pittsburgh PA 15260 USA
- McGowan Institute for Regenerative Medicine Pittsburgh PA 15260 USA
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15
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Kharbikar BN, Chendke GS, Desai TA. Modulating the foreign body response of implants for diabetes treatment. Adv Drug Deliv Rev 2021; 174:87-113. [PMID: 33484736 PMCID: PMC8217111 DOI: 10.1016/j.addr.2021.01.011] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 12/30/2020] [Accepted: 01/10/2021] [Indexed: 02/06/2023]
Abstract
Diabetes Mellitus is a group of diseases characterized by high blood glucose levels due to patients' inability to produce sufficient insulin. Current interventions often require implants that can detect and correct high blood glucose levels with minimal patient intervention. However, these implantable technologies have not reached their full potential in vivo due to the foreign body response and subsequent development of fibrosis. Therefore, for long-term function of implants, modulating the initial immune response is crucial in preventing the activation and progression of the immune cascade. This review discusses the different molecular mechanisms and cellular interactions involved in the activation and progression of foreign body response (FBR) and fibrosis, specifically for implants used in diabetes. We also highlight the various strategies and techniques that have been used for immunomodulation and prevention of fibrosis. We investigate how these general strategies have been applied to implants used for the treatment of diabetes, offering insights on how these devices can be further modified to circumvent FBR and fibrosis.
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Affiliation(s)
- Bhushan N Kharbikar
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Gauree S Chendke
- University of California Berkeley - University of California San Francisco Graduate Program in Bioengineering, San Francisco, CA 94143, USA
| | - Tejal A Desai
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, CA 94143, USA; University of California Berkeley - University of California San Francisco Graduate Program in Bioengineering, San Francisco, CA 94143, USA; Department of Bioengineering, University of California, Berkeley, CA 94720, USA.
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16
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Long Y, Li J, Yang F, Wang J, Wang X. Wearable and Implantable Electroceuticals for Therapeutic Electrostimulations. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2021; 8:2004023. [PMID: 33898184 PMCID: PMC8061371 DOI: 10.1002/advs.202004023] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Revised: 11/20/2020] [Indexed: 05/21/2023]
Abstract
Wearable and implantable electroceuticals (WIEs) for therapeutic electrostimulation (ES) have become indispensable medical devices in modern healthcare. In addition to functionality, device miniaturization, conformability, biocompatibility, and/or biodegradability are the main engineering targets for the development and clinical translation of WIEs. Recent innovations are mainly focused on wearable/implantable power sources, advanced conformable electrodes, and efficient ES on targeted organs and tissues. Herein, nanogenerators as a hotspot wearable/implantable energy-harvesting technique suitable for powering WIEs are reviewed. Then, electrodes for comfortable attachment and efficient delivery of electrical signals to targeted tissue/organ are introduced and compared. A few promising application directions of ES are discussed, including heart stimulation, nerve modulation, skin regeneration, muscle activation, and assistance to other therapeutic modalities.
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Affiliation(s)
- Yin Long
- Department of Material Science and EngineeringUniversity of Wisconsin–MadisonMadisonWI53706USA
| | - Jun Li
- Department of Material Science and EngineeringUniversity of Wisconsin–MadisonMadisonWI53706USA
| | - Fan Yang
- Department of Material Science and EngineeringUniversity of Wisconsin–MadisonMadisonWI53706USA
| | - Jingyu Wang
- Department of Material Science and EngineeringUniversity of Wisconsin–MadisonMadisonWI53706USA
| | - Xudong Wang
- Department of Material Science and EngineeringUniversity of Wisconsin–MadisonMadisonWI53706USA
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17
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Sharon A, Jankowski MM, Shmoel N, Erez H, Spira ME. Inflammatory Foreign Body Response Induced by Neuro-Implants in Rat Cortices Depleted of Resident Microglia by a CSF1R Inhibitor and Its Implications. Front Neurosci 2021; 15:646914. [PMID: 33841088 PMCID: PMC8032961 DOI: 10.3389/fnins.2021.646914] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Accepted: 02/25/2021] [Indexed: 12/30/2022] Open
Abstract
Inflammatory encapsulation of implanted cortical-neuro-probes [the foreign body response (FBR)] severely limits their use in basic brain research and in clinical applications. A better understanding of the inflammatory FBR is needed to effectively mitigate these critical limitations. Combining the use of the brain permeant colony stimulating factor 1 receptor inhibitor PLX5622 and a perforated polyimide-based multielectrode array platform (PPMP) that can be sectioned along with the surrounding tissue, we examined the contribution of microglia to the formation of inflammatory FBR. To that end, we imaged the inflammatory processes induced by PPMP implantations after eliminating 89-94% of the cortical microglia by PLX5622 treatment. The observations showed that: (I) inflammatory encapsulation of implanted PPMPs proceeds by astrocytes in microglia-free cortices. The activated astrocytes adhered to the PPMP's surfaces. This suggests that the roles of microglia in the FBR might be redundant. (II) PPMP implantation into control or continuously PLX5622-treated rats triggered a localized surge of microglia mitosis. The daughter cells that formed a "cloud" of short-lived (T 1 / 2 ≤ 14 days) microglia around and in contact with the implant surfaces were PLX5622 insensitive. (III) Neuron degeneration by PPMP implantation and the ensuing recovery in time, space, and density progressed in a similar manner in the cortices following 89-94% depletion of microglia. This implies that microglia do not serve a protective role with respect to the neurons. (IV) Although the overall cell composition and dimensions of the encapsulating scar in PLX5622-treated rats differed from the controls, the recorded field potential (FP) qualities and yield were undistinguishable. This is accounted for by assuming that the FP amplitudes in the control and PLX5622-treated rats were related to the seal resistance formed at the interface between the adhering microglia and/or astrocytes and the PPMP platform rather than across the scar tissue. These observations suggest that the prevention of both astrocytes and microglia adhesion to the electrodes is required to improve FP recording quality and yield.
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Affiliation(s)
- Aviv Sharon
- Department of Neurobiology, The Alexander Silberman Institute of Life Science, The Hebrew University of Jerusalem, Jerusalem, Israel
- The Charles E. Smith Family and Prof. Joel Elkes Laboratory for Collaborative Research in Psychobiology, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Maciej M. Jankowski
- Department of Neurobiology, The Alexander Silberman Institute of Life Science, The Hebrew University of Jerusalem, Jerusalem, Israel
- The Charles E. Smith Family and Prof. Joel Elkes Laboratory for Collaborative Research in Psychobiology, The Hebrew University of Jerusalem, Jerusalem, Israel
- Edmond and Lily Safra Center for Brain Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Nava Shmoel
- Department of Neurobiology, The Alexander Silberman Institute of Life Science, The Hebrew University of Jerusalem, Jerusalem, Israel
- The Charles E. Smith Family and Prof. Joel Elkes Laboratory for Collaborative Research in Psychobiology, The Hebrew University of Jerusalem, Jerusalem, Israel
- The Harvey M. Kruger Family Center for Nanoscience, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Hadas Erez
- Department of Neurobiology, The Alexander Silberman Institute of Life Science, The Hebrew University of Jerusalem, Jerusalem, Israel
- The Charles E. Smith Family and Prof. Joel Elkes Laboratory for Collaborative Research in Psychobiology, The Hebrew University of Jerusalem, Jerusalem, Israel
- The Harvey M. Kruger Family Center for Nanoscience, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Micha E. Spira
- Department of Neurobiology, The Alexander Silberman Institute of Life Science, The Hebrew University of Jerusalem, Jerusalem, Israel
- The Charles E. Smith Family and Prof. Joel Elkes Laboratory for Collaborative Research in Psychobiology, The Hebrew University of Jerusalem, Jerusalem, Israel
- The Harvey M. Kruger Family Center for Nanoscience, The Hebrew University of Jerusalem, Jerusalem, Israel
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18
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Garrudo FFF, Mikael PE, Rodrigues CAV, Udangawa RW, Paradiso P, Chapman CA, Hoffman P, Colaço R, Cabral JMS, Morgado J, Linhardt RJ, Ferreira FC. Polyaniline-polycaprolactone fibers for neural applications: Electroconductivity enhanced by pseudo-doping. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2020; 120:111680. [PMID: 33545842 DOI: 10.1016/j.msec.2020.111680] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Revised: 10/21/2020] [Accepted: 10/22/2020] [Indexed: 12/15/2022]
Abstract
Replenishing neurons in patients with neurodegenerative diseases is one of the ultimate therapies for these progressive, debilitating and fatal diseases. Electrical stimulation can improve neuron stem cell differentiation but requires a reliable nanopatterned electroconductive substrate. Potential candidate substrates are polycaprolactone (PCL) - polyaniline:camphorsulfonic acid (PANI:CSA) nanofibers, but their nanobiophysical properties need to be finetuned. The present study investigates the use of the pseudo-doping effect on the optimization of the electroconductivity of these polyaniline-based electrospun nanofibers. This was performed by developing a new solvent system that comprises a mixture of hexafluoropropanol (HFP) and trifluoroethanol (TFE). For the first time, an electroconductivity so high as 0.2 S cm-1 was obtained for, obtained from a TFE:HFP 50/50 vol% solution, while maintaining fiber biocompatibility. The physicochemical mechanisms behind these changes were studied. The results suggest HFP promotes changes on PANI chains conformations through pseudo-doping, leading to the observed enhancement in electroconductivity. The consequences of such change in the nanofabrication of PCL-PANI fibers include an increase in fiber diameter (373 ± 172 nm), a decrease in contact angle (42 ± 3°) and a decrease in Young modulus (1.6 ± 0.5 MPa), making these fibers interesting candidates for neural tissue engineering. Electrical stimulation of differentiating neural stem cells was performed using AC electrical current. Positive effects on cell alignment and gene expression (DCX, MAP2) are observed. The novel optimized platform shows promising applications for (1) building in vitro platforms for drug screening, (2) interfaces for deep-brain electrodes; and (3) fully grown and functional neurons transplantation.
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Affiliation(s)
- Fábio F F Garrudo
- Department of Chemistry and Chemical Biology, Center for Biotechnology & Interdisciplinary Studies, Rensselaer Polytechnic Institute, Biotechnology Center 4005, Troy, NY 12180, USA; Department of Bioengineering and Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, Lisboa 1049-001, Portugal; Department of Bioengineering and Instituto de Telecomunicações, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa, Portugal
| | - Paiyz E Mikael
- Department of Chemistry and Chemical Biology, Center for Biotechnology & Interdisciplinary Studies, Rensselaer Polytechnic Institute, Biotechnology Center 4005, Troy, NY 12180, USA
| | - Carlos A V Rodrigues
- Department of Bioengineering and Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, Lisboa 1049-001, Portugal
| | - Ranodhi W Udangawa
- Department of Chemistry and Chemical Biology, Center for Biotechnology & Interdisciplinary Studies, Rensselaer Polytechnic Institute, Biotechnology Center 4005, Troy, NY 12180, USA
| | - Patrizia Paradiso
- IDMEC - Instituto de Engenharia Mecânica, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal
| | - Caitlyn A Chapman
- Department of Chemistry and Chemical Biology, Center for Biotechnology & Interdisciplinary Studies, Rensselaer Polytechnic Institute, Biotechnology Center 4005, Troy, NY 12180, USA
| | - Pauline Hoffman
- Department of Chemistry and Chemical Biology, Center for Biotechnology & Interdisciplinary Studies, Rensselaer Polytechnic Institute, Biotechnology Center 4005, Troy, NY 12180, USA
| | - Rogério Colaço
- IDMEC - Instituto de Engenharia Mecânica, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal
| | - Joaquim M S Cabral
- Department of Bioengineering and Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, Lisboa 1049-001, Portugal
| | - Jorge Morgado
- Department of Bioengineering and Instituto de Telecomunicações, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa, Portugal
| | - Robert J Linhardt
- Department of Chemistry and Chemical Biology, Center for Biotechnology & Interdisciplinary Studies, Rensselaer Polytechnic Institute, Biotechnology Center 4005, Troy, NY 12180, USA.
| | - Frederico Castelo Ferreira
- Department of Bioengineering and Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, Lisboa 1049-001, Portugal.
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19
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Sikder MKU, Tong W, Pingle H, Kingshott P, Needham K, Shivdasani MN, Fallon JB, Seligman P, Ibbotson MR, Prawer S, Garrett DJ. Laminin coated diamond electrodes for neural stimulation. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2020; 118:111454. [PMID: 33255039 DOI: 10.1016/j.msec.2020.111454] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Revised: 07/15/2020] [Accepted: 08/25/2020] [Indexed: 12/20/2022]
Abstract
The performance of many implantable neural stimulation devices is degraded due to the loss of neurons around the electrodes by the body's natural biological responses to a foreign material. Coating of electrodes with biomolecules such as extracellular matrix proteins is one potential route to suppress the adverse responses that lead to loss of implant functionality. Concurrently, however, the electrochemical performance of the stimulating electrode must remain optimal to continue to safely provide sufficient charge for neural stimulation. We have previously found that oxygen plasma treated nitrogen included ultrananocrystalline diamond coated platinum electrodes exhibit superior charge injection capacity and electrochemical stability for neural stimulation (Sikder et al., 2019). To fabricate bioactive diamond electrodes, in this work, laminin, an extracellular matrix protein known to be involved in inter-neuron adhesion and recognition, was used as an example biomolecule. Here, laminin was covalently coupled to diamond electrodes. Electrochemical analysis found that the covalently coupled films were robust and resulted in minimal change to the charge injection capacity of diamond electrodes. The successful binding of laminin and its biological activity was further confirmed using primary rat cortical neuron cultures, and the coated electrodes showed enhanced cell attachment densities and neurite outgrowth. The method proposed in this work is versatile and adaptable to many other biomolecules for producing bioactive diamond electrodes, which are expected to show reduced the inflammatory responses in vivo.
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Affiliation(s)
- Md Kabir Uddin Sikder
- Department of Medical Bionics, The University of Melbourne, Parkville, Melbourne, VIC 3010, Australia; Bionics Institute, 384 Albert St, East Melbourne, VIC 3002, Australia; Department of Physics, Jahangirnagar University, Savar, Dhaka 1342, Bangladesh
| | - Wei Tong
- National Vision Research Institute, Australian College of Optometry, Carlton, VIC 3010, Australia; School of Physics, The University of Melbourne, Parkville, Melbourne, VIC 3010, Australia; Department of Optometry and Vision Sciences, Melbourne School of Health Sciences, The University of Melbourne, Parkville, VIC 3010, Australia.
| | - Hitesh Pingle
- ARC Training Centre Training Centre in Surface Engineering for Advanced Materials (SEAM), Department of Chemistry and Biotechnology, Swinburne University of Technology, Hawthorn, Victoria, Australia
| | - Peter Kingshott
- ARC Training Centre Training Centre in Surface Engineering for Advanced Materials (SEAM), Department of Chemistry and Biotechnology, Swinburne University of Technology, Hawthorn, Victoria, Australia
| | - Karina Needham
- Department of Otolaryngology, The University of Melbourne, Royal Victorian Eye & Ear Hospital, East Melbourne, Australia
| | - Mohit N Shivdasani
- Bionics Institute, 384 Albert St, East Melbourne, VIC 3002, Australia; Graduate School of Biomedical Engineering, The University of New South Wales, Kensington, NSW 2033, Australia
| | - James B Fallon
- Department of Medical Bionics, The University of Melbourne, Parkville, Melbourne, VIC 3010, Australia; Bionics Institute, 384 Albert St, East Melbourne, VIC 3002, Australia; Department of Otolaryngology, The University of Melbourne, Royal Victorian Eye & Ear Hospital, East Melbourne, Australia
| | - Peter Seligman
- Bionics Institute, 384 Albert St, East Melbourne, VIC 3002, Australia
| | - Michael R Ibbotson
- National Vision Research Institute, Australian College of Optometry, Carlton, VIC 3010, Australia; Department of Optometry and Vision Sciences, Melbourne School of Health Sciences, The University of Melbourne, Parkville, VIC 3010, Australia
| | - Steven Prawer
- School of Physics, The University of Melbourne, Parkville, Melbourne, VIC 3010, Australia
| | - David J Garrett
- School of Physics, The University of Melbourne, Parkville, Melbourne, VIC 3010, Australia; RMIT University, School of Engineering, Melbourne, VIC 3001, Australia
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20
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Yang Q, Wu B, Eles JR, Vazquez AL, Kozai TDY, Cui XT. Zwitterionic Polymer Coating Suppresses Microglial Encapsulation to Neural Implants In Vitro and In Vivo. ADVANCED BIOSYSTEMS 2020; 4:e1900287. [PMID: 32363792 PMCID: PMC7686959 DOI: 10.1002/adbi.201900287] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Revised: 03/23/2020] [Accepted: 03/30/2020] [Indexed: 01/08/2023]
Abstract
For brain computer interfaces (BCI), the immune response to implanted electrodes is a major biological cause of device failure. Bioactive coatings such as neural adhesion molecule L1 have been shown to improve the biocompatibility, but are difficult to handle or produce in batches. Here, a synthetic zwitterionic polymer coating, poly(sulfobetaine methacrylate) (PSBMA) is developed for neural implants with the goal of reducing the inflammatory host response. In tests in vitro, the zwitterionic coating inhibits protein adsorption and the attachment of fibroblasts and microglia, and remains stable for at least 4 weeks. In vivo two-photon microscopy on CX3CR1-GFP mice shows that the zwitterionic coating significantly suppresses the microglial encapsulation of neural microelectrodes over a 6 h observation period. Furthermore, the lower microglial encapsulation on zwitterionic polymer-coated microelectrodes is revealed to originate from a reduction in the size but not the number of microglial end feet. This work provides a facile method for coating neural implants with zwitterionic polymers and illustrates the initial interaction between microglia and coated surface at high temporal and spatial resolution.
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Affiliation(s)
- Qianru Yang
- Biomedical Science Tower 3, University of Pittsburgh, 3501 Fifth Ave, Pittsburgh, PA, 15232, USA
| | - Bingchen Wu
- Biomedical Science Tower 3, University of Pittsburgh, 3501 Fifth Ave, Pittsburgh, PA, 15232, USA
| | - James R Eles
- Biomedical Science Tower 3, University of Pittsburgh, 3501 Fifth Ave, Pittsburgh, PA, 15232, USA
| | - Alberto L Vazquez
- McGowan Institute for Regenerative Medicine, University of Pittsburgh, 3025 East Carson Street, Pittsburgh, PA, 15219, USA
| | - Takashi D Y Kozai
- Center for Biotechnology and Bioengineering, University of Pittsburgh, 300 Technology Dr, Pittsburgh, PA, 15213, USA
| | - X Tracy Cui
- Biomedical Science Tower 3, University of Pittsburgh, 3501 Fifth Ave, Pittsburgh, PA, 15232, USA
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21
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Neuroadhesive protein coating improves the chronic performance of neuroelectronics in mouse brain. Biosens Bioelectron 2020; 155:112096. [PMID: 32090868 DOI: 10.1016/j.bios.2020.112096] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2019] [Revised: 02/06/2020] [Accepted: 02/12/2020] [Indexed: 12/15/2022]
Abstract
Intracortical microelectrodes are being developed to both record and stimulate neurons to understand brain circuitry or restore lost functions. However, the success of these probes is hampered partly due to the inflammatory host tissue responses to implants. To minimize the foreign body reactions, L1, a brain derived neuronal specific cell adhesion molecule, has been covalently bound to the neural electrode array surface. Here we evaluated the chronic recording performance of L1-coated silicon based laminar neural electrode arrays implanted into V1m cortex of mice. The L1 coating enhanced the overall visually evoked single-unit (SU) yield and SU amplitude, as well as signal-to-noise-ratio (SNR) in the mouse brain compared to the uncoated arrays across the 0-1500 μm depth. The improvement in recording is most dramatic in the hippocampus region, where the control group showed severe recording yield decrease after one week, while the L1 implants maintained a high SU yield throughout the 16 weeks. Immunohistological analysis revealed significant increases of axonal and neuronal density along with significantly lowered microglia activation around the L1 probe after 16 weeks. These results collectively confirm the effectiveness of L1 based biomimetic coating on minimizing inflammatory tissue response and improving neural recording quality and longevity. Improving chronic recording will benefit the brain-computer interface technologies and neuroscience studies involving chronic tracking of neural activities.
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22
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Yang JC, Mun J, Kwon SY, Park S, Bao Z, Park S. Electronic Skin: Recent Progress and Future Prospects for Skin-Attachable Devices for Health Monitoring, Robotics, and Prosthetics. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2019; 31:e1904765. [PMID: 31538370 DOI: 10.1002/adma.201904765] [Citation(s) in RCA: 464] [Impact Index Per Article: 92.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Revised: 08/26/2019] [Indexed: 05/17/2023]
Abstract
Recent progress in electronic skin or e-skin research is broadly reviewed, focusing on technologies needed in three main applications: skin-attachable electronics, robotics, and prosthetics. First, since e-skin will be exposed to prolonged stresses of various kinds and needs to be conformally adhered to irregularly shaped surfaces, materials with intrinsic stretchability and self-healing properties are of great importance. Second, tactile sensing capability such as the detection of pressure, strain, slip, force vector, and temperature are important for health monitoring in skin attachable devices, and to enable object manipulation and detection of surrounding environment for robotics and prosthetics. For skin attachable devices, chemical and electrophysiological sensing and wireless signal communication are of high significance to fully gauge the state of health of users and to ensure user comfort. For robotics and prosthetics, large-area integration on 3D surfaces in a facile and scalable manner is critical. Furthermore, new signal processing strategies using neuromorphic devices are needed to efficiently process tactile information in a parallel and low power manner. For prosthetics, neural interfacing electrodes are of high importance. These topics are discussed, focusing on progress, current challenges, and future prospects.
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Affiliation(s)
- Jun Chang Yang
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea
| | - Jaewan Mun
- Department of Chemical Engineering, Stanford University, Stanford, CA, 94305-5025, USA
| | - Se Young Kwon
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea
| | - Seongjun Park
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea
- Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea
| | - Zhenan Bao
- Department of Chemical Engineering, Stanford University, Stanford, CA, 94305-5025, USA
| | - Steve Park
- Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea
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23
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Wu B, Cao B, Taylor IM, Woeppel K, Cui XT. Facile Synthesis of a 3,4-Ethylene-Dioxythiophene (EDOT) Derivative for Ease of Bio-Functionalization of the Conducting Polymer PEDOT. Front Chem 2019; 7:178. [PMID: 30984745 PMCID: PMC6450363 DOI: 10.3389/fchem.2019.00178] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Accepted: 03/07/2019] [Indexed: 11/21/2022] Open
Abstract
In the pursuit of conducting polymer based bio-functional devices, a cost-effective and high yield synthesis method for a versatile monomer is desired. We report here a new synthesis strategy for a versatile monomer 2-methylene-2,3-dihydrothieno (3,4-b) (1,4) dioxine, or 3,4-ethylenedioxythiophene with a exomethylene side group (EDOT-EM). Compared to the previously reported synthesis route, the new strategy uses less steps, with faster reaction rate, and higher yield. The presence of EM group opens up endless possibility for derivatization via either hydro-alkoxy addition or thiol-ene click chemistry. EDOT-EM could be polymerized into stable and low impedance PEDOT-EM polymer using electro-polymerization method on different conducting substrates at both macro and micro scales. Facile post-functionalization of PEDOT-EM with molecules of varying size and functionality (from small molecules to DNAs and proteins) was achieved. The new synthetic route of EDOT-EM and the ease of post-functionalization of PEDOT-EM will greatly accelerate the use of conducting polymer in a broad range of organic electronics and bioelectronics applications.
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Affiliation(s)
- Bingchen Wu
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, United States
- Center for the Neural Basis of Cognition, University of Pittsburgh, Pittsburgh, PA, United States
| | - Bin Cao
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, United States
| | - Ian Mitch Taylor
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, United States
| | - Kevin Woeppel
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, United States
- Center for the Neural Basis of Cognition, University of Pittsburgh, Pittsburgh, PA, United States
| | - Xinyan Tracy Cui
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, United States
- Center for the Neural Basis of Cognition, University of Pittsburgh, Pittsburgh, PA, United States
- McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA, United States
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Park S, Loke G, Fink Y, Anikeeva P. Flexible fiber-based optoelectronics for neural interfaces. Chem Soc Rev 2019; 48:1826-1852. [PMID: 30815657 DOI: 10.1039/c8cs00710a] [Citation(s) in RCA: 65] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Neurological and psychiatric conditions pose an increasing socioeconomic burden on our aging society. Our ability to understand and treat these conditions relies on the development of reliable tools to study the dynamics of the underlying neural circuits. Despite significant progress in approaches and devices to sense and modulate neural activity, further refinement is required on the spatiotemporal resolution, cell-type selectivity, and long-term stability of neural interfaces. Guided by the principles of neural transduction and by the materials properties of the neural tissue, recent advances in neural interrogation approaches rely on flexible and multifunctional devices. Among these approaches, multimaterial fibers have emerged as integrated tools for sensing and delivering of multiple signals to and from the neural tissue. Fiber-based neural probes are produced by thermal drawing process, which is the manufacturing approach used in optical fiber fabrication. This technology allows straightforward incorporation of multiple functional components into microstructured fibers at the level of their macroscale models, preforms, with a wide range of geometries. Here we will introduce the multimaterial fiber technology, its applications in engineering fields, and its adoption for the design of multifunctional and flexible neural interfaces. We will discuss examples of fiber-based neural probes tailored to the electrophysiological recording, optical neuromodulation, and delivery of drugs and genes into the rodent brain and spinal cord, as well as their emerging use for studies of nerve growth and repair.
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Affiliation(s)
- Seongjun Park
- School of Engineering, Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
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25
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Modulation of cell-cell interactions for neural tissue engineering: Potential therapeutic applications of cell adhesion molecules in nerve regeneration. Biomaterials 2019; 197:327-344. [DOI: 10.1016/j.biomaterials.2019.01.030] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Revised: 12/08/2018] [Accepted: 01/20/2019] [Indexed: 12/21/2022]
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Tsui C, Koss K, Churchward MA, Todd KG. Biomaterials and glia: Progress on designs to modulate neuroinflammation. Acta Biomater 2019; 83:13-28. [PMID: 30414483 DOI: 10.1016/j.actbio.2018.11.008] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Revised: 10/05/2018] [Accepted: 11/06/2018] [Indexed: 02/06/2023]
Abstract
Microglia are multi-functional cells that play a vital role in establishing and maintaining the function of the nervous system and determining the fate of neurons following injury or neuropathology. The roles of microglia are diverse and essential to the capacity of the nervous system to recover from injury, however sustained inflammation can limit recovery and drive chronic disease processes such as neurodegenerative disorders. When assessing implantable therapeutic devices in the central nervous system, an improved lifetime of the implant is considered achievable through the attenuation of microglial inflammation. Consequently, there is a tremendous underexplored potential in biomaterial and engineered design to modulate neuroinflammation for therapeutic benefit. Several strategies for improving device compatibility reviewed here include: biocompatible coatings, improved designs in finer and flexible shapes to reduce tissue shear-related scarring, and loading of anti-inflammatory drugs. Studies about microglial cell cultures in 3D hydrogels and nanoscaffolds to assess various injuries and disorders are also discussed. A variety of other microglia-targeting treatments are also reviewed, including nanoparticulate systems, cellular backpacks, and gold plinths, with the intention of delivering anti-inflammatory drugs by targeting the phagocytic nature of microglia. Overall, this review highlights recent advances in biomaterials targeting microglia and inflammatory function with the potential for improving implant rejection and biocompatibility studies. STATEMENT OF SIGNIFICANCE: Microglia are the resident immune cells of the central nervous system, and thus play a central role in the neuroinflammatory response against conditions than span acute injuries, neuropsychiatric disorders, and neurodegenerative disorders. This review article presents a summary of biomaterials research that target microglia and other glial cells in order to attenuate neuroinflammation, including but not limited to: design of mechanically compliant and biocompatible stimulation electrodes, hydrogels for high-throughput 3D modelling of nervous tissue, and uptake of nanoparticle drug delivery systems. The goal of this paper is to identify strengths and gaps in the relevant literature, and to promote further consideration of microglia behaviour and neuroinflammation in biomaterial design.
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Affiliation(s)
- C Tsui
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB T6G 2R3, Canada; Department of Biomedical Engineering, University of Alberta, Edmonton, AB T6G 2R3, Canada
| | - K Koss
- Neurochemical Research Unit, Department of Psychiatry, University of Alberta, Edmonton, AB T6G 2R3, Canada; Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB T6G 2R3, Canada
| | - M A Churchward
- Neurochemical Research Unit, Department of Psychiatry, University of Alberta, Edmonton, AB T6G 2R3, Canada; Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB T6G 2R3, Canada
| | - K G Todd
- Neurochemical Research Unit, Department of Psychiatry, University of Alberta, Edmonton, AB T6G 2R3, Canada; Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB T6G 2R3, Canada; Department of Biomedical Engineering, University of Alberta, Edmonton, AB T6G 2R3, Canada.
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Eles JR, Vazquez AL, Kozai TDY, Cui XT. Meningeal inflammatory response and fibrous tissue remodeling around intracortical implants: An in vivo two-photon imaging study. Biomaterials 2018; 195:111-123. [PMID: 30634095 DOI: 10.1016/j.biomaterials.2018.12.031] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2018] [Revised: 12/15/2018] [Accepted: 12/28/2018] [Indexed: 12/21/2022]
Abstract
Meningeal inflammation and encapsulation of neural electrode arrays is a leading cause of device failure, yet little is known about how it develops over time or what triggers it. This work characterizes the dynamic changes of meningeal inflammatory cells and collagen-I in order to understand the meningeal tissue response to neural electrode implantation. We use in vivo two-photon microscopy of CX3CR1-GFP mice over the first month after electrode implantation to quantify changes in inflammatory cell behavior as well as meningeal collagen-I remodeling. We define a migratory window during the first day after electrode implantation hallmarked by robust inflammatory cell migration along electrodes in the meninges as well as cell trafficking through meningeal venules. This migratory window attenuates by 2 days post-implant, but over the next month, the meningeal collagen-I remodels to conform to the surface of the electrode and thickens. This work shows that there are distinct time courses for initial meningeal inflammatory cell infiltration and meningeal collagen-I remodeling. This may indicate a therapeutic window early after implantation for modulation and mitigation of meningeal inflammation.
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Affiliation(s)
- J R Eles
- Bioengineering, University of Pittsburgh, United States; Center for the Neural Basis of Cognition, University of Pittsburgh and Carnegie Mellon University, United States
| | - A L Vazquez
- Bioengineering, University of Pittsburgh, United States; Center for the Neural Basis of Cognition, University of Pittsburgh and Carnegie Mellon University, United States; Radiology, University of Pittsburgh, United States
| | - T 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; Center for Neuroscience, University of Pittsburgh, United States
| | - X T 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.
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28
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Zuidema JM, Gilbert RJ, Gottipati MK. Biomaterial Approaches to Modulate Reactive Astroglial Response. Cells Tissues Organs 2018; 205:372-395. [PMID: 30517922 PMCID: PMC6397084 DOI: 10.1159/000494667] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Accepted: 10/18/2018] [Indexed: 11/19/2022] Open
Abstract
Over several decades, biomaterial scientists have developed materials to spur axonal regeneration and limit secondary injury and tested these materials within preclinical animal models. Rarely, though, are astrocytes examined comprehensively when biomaterials are placed into the injury site. Astrocytes support neuronal function in the central nervous system. Following an injury, astrocytes undergo reactive gliosis and create a glial scar. The astrocytic glial scar forms a dense barrier which restricts the extension of regenerating axons through the injury site. However, there are several beneficial effects of the glial scar, including helping to reform the blood-brain barrier, limiting the extent of secondary injury, and supporting the health of regenerating axons near the injury site. This review provides a brief introduction to the role of astrocytes in the spinal cord, discusses astrocyte phenotypic changes that occur following injury, and highlights studies that explored astrocyte changes in response to biomaterials tested within in vitro or in vivo environments. Overall, we suggest that in order to improve biomaterial designs for spinal cord injury applications, investigators should more thoroughly consider the astrocyte response to such designs.
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Affiliation(s)
- Jonathan M Zuidema
- Department of Chemistry and Biochemistry, University of California, San Diego, California, USA
| | - Ryan J Gilbert
- Department of Biomedical Engineering, Rensselaer Polytechnic Institute, Troy, New York, USA
- Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, New York, USA
| | - Manoj K Gottipati
- Department of Biomedical Engineering, Rensselaer Polytechnic Institute, Troy, New York, USA,
- Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, New York, USA,
- Center for Brain and Spinal Cord Repair, Department of Neuroscience, The Ohio State University, Columbus, Ohio, USA,
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30
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Hill M, Rios E, Sudhakar SK, Roossien DH, Caldwell C, Cai D, Ahmed OJ, Lempka SF, Chestek CA. Quantitative simulation of extracellular single unit recording from the surface of cortex. J Neural Eng 2018; 15:056007. [PMID: 29923502 DOI: 10.1088/1741-2552/aacdb8] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
OBJECTIVE Neural recording is important for a wide variety of clinical applications. Until recently, recording from the surface of the brain, even when using micro-electrocorticography (μECoG) arrays, was not thought to enable recording from individual neurons. Recent results suggest that when the surface electrode contact size is sufficiently small, it may be possible to record single neurons from the brain's surface. In this study, we use computational techniques to investigate the ability of surface electrodes to record the activity of single neurons. APPROACH The computational model included the rat head, μECoG electrode, two existing multi-compartmental neuron models, and a novel multi-compartmental neuron model derived from patch clamp experiments in layer 1 of the cortex. MAIN RESULTS Using these models, we reproduced single neuron recordings from μECoG arrays, and elucidated their possible source. The model resembles the experimental data when spikes originate from layer 1 neurons that are less than 60 μm from the cortical surface. We further used the model to explore the design space for surface electrodes. Although this model does not include biological or thermal noise, the results indicate the electrode contact area should be 100 μm2 or smaller to maintain a detectable waveform amplitude. Furthermore, the model shows the width of lateral insulation could be reduced, which may reduce scar formation, while retaining 95% of signal amplitude. SIGNIFICANCE Overall, the model suggests single-unit surface recording is limited to neurons in layer 1 and further improvement in electrode design is needed.
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Affiliation(s)
- Mackenna Hill
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, United State of America. Department of Biomedical Engineering, Duke University, Durham, NC, United State of America
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31
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Chen N, Luo B, Yang IH, Thakor NV, Ramakrishna S. Biofunctionalized platforms towards long-term neural interface. CURRENT OPINION IN BIOMEDICAL ENGINEERING 2018. [DOI: 10.1016/j.cobme.2018.03.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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32
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Woeppel KM, Zheng XS, Cui XT. Enhancing surface immobilization of bioactive molecules via a silica nanoparticle based coating. J Mater Chem B 2018; 6:3058-3067. [PMID: 30464839 PMCID: PMC6242288 DOI: 10.1039/c8tb00408k] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Surface modification is of significant interest in biomaterials, biosensors, and device biocompatibility. Immobilization of bioactive or biomimetic molecules is a common method of disguising a foreign body as host tissue to decrease the foreign body response (FBR) and/or increase device-tissue integration. For example, in neural interfacing devices, immobilization of L1, a neuron-specific adhesion molecule, has been shown to increase neuron adhesion and reduce inflammatory gliosis on and around the implants. However, the activity of modified surfaces is limited by the relatively low concentration of the immobilized component, in part due to the low surface area of flat surfaces available for modification. In this work, we demonstrate a novel method for increasing the device surface area by attaching a layer of thiolated silica nanoparticles (TNPs). This coating method results in an almost two-fold increase in the immobilized L1 protein. L1 immobilized nanotextured surfaces showed a 100% increase in neurite outgrowth than smooth L1 immobilized surfaces without increasing the adhesion of astrocytes in vitro. The increased bioactivity observed in the cell assay was determined to be mainly due to the higher protein surface density, not the increase in surface roughness. In addition, we tested immobilization of a superoxide dismutase mimic (SODm) on smooth and roughened substrates. The SODm immobilized rough surfaces demonstrated an increase of 145% in superoxide scavenging activity compared to chemically matched smooth surfaces. These results not only show promise in improving biomimetic coating for neural implants, but may also improve surface immobilization efficacy in other fields such as catalysts, protein purification, sensors, and tissue engineering devices.
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Affiliation(s)
- K M Woeppel
- University of Pittsburgh, Department of Bioengineering, 5057 Biomedical Science Tower 3, 3501 Fifth Ave, Pittsburgh, Pa, 15213, USA
- Center for the Neural Basis of Cognition, University of Pittsburgh, Pittsburgh, Pa, 15213, USA
| | - X S Zheng
- University of Pittsburgh, Department of Bioengineering, 5057 Biomedical Science Tower 3, 3501 Fifth Ave, Pittsburgh, Pa, 15213, USA
| | - X T Cui
- University of Pittsburgh, Department of Bioengineering, 5057 Biomedical Science Tower 3, 3501 Fifth Ave, Pittsburgh, Pa, 15213, USA
- Center for the Neural Basis of Cognition, University of Pittsburgh, Pittsburgh, Pa, 15213, USA
- McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, Pa, 15213, USA
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33
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Cody PA, Eles JR, Lagenaur CF, Kozai TDY, Cui XT. Unique electrophysiological and impedance signatures between encapsulation types: An analysis of biological Utah array failure and benefit of a biomimetic coating in a rat model. Biomaterials 2018; 161:117-128. [PMID: 29421549 PMCID: PMC5817007 DOI: 10.1016/j.biomaterials.2018.01.025] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2017] [Revised: 01/10/2018] [Accepted: 01/16/2018] [Indexed: 12/16/2022]
Abstract
Intracortical microelectrode arrays, especially the Utah array, remain the most common choice for obtaining high dimensional recordings of spiking neural activity for brain computer interface and basic neuroscience research. Despite the widespread use and established design, mechanical, material and biological challenges persist that contribute to a steady decline in recording performance (as evidenced by both diminished signal amplitude and recorded cell population over time) or outright array failure. Device implantation injury causes acute cell death and activation of inflammatory microglia and astrocytes that leads to a chronic neurodegeneration and inflammatory glial aggregation around the electrode shanks and often times fibrous tissue growth above the pia along the bed of the array within the meninges. This multifaceted deleterious cascade can result in substantial variability in performance even under the same experimental conditions. We track both impedance signatures and electrophysiological performance of 4 × 4 floating microelectrode Utah arrays implanted in the primary monocular visual cortex (V1m) of Long-Evans rats over a 12-week period. We employ a repeatable visual stimulation method to compare signal-to-noise ratio as well as single- and multi-unit yield from weekly recordings. To explain signal variability with biological response, we compare arrays categorized as either Type 1, partial fibrous encapsulation, or Type 2, complete fibrous encapsulation and demonstrate performance and impedance signatures unique to encapsulation type. We additionally assess benefits of a biomolecule coating intended to minimize distance to recordable units and observe a temporary improvement on multi-unit recording yield and single-unit amplitude.
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Affiliation(s)
- Patrick A Cody
- Department of Bioengineering, University of Pittsburgh, 5057 Biomedical Science Tower 3, 3501 Fifth Avenue, Pittsburgh, PA, 15260, USA; Center for the Neural Basis of Cognition, University of Pittsburgh, Pittsburgh, PA, USA
| | - James R Eles
- Department of Bioengineering, University of Pittsburgh, 5057 Biomedical Science Tower 3, 3501 Fifth Avenue, Pittsburgh, PA, 15260, USA; Center for the Neural Basis of Cognition, University of Pittsburgh, Pittsburgh, PA, USA
| | - Carl F Lagenaur
- Department of Neurobiology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Takashi D Y Kozai
- Department of Bioengineering, University of Pittsburgh, 5057 Biomedical Science Tower 3, 3501 Fifth Avenue, Pittsburgh, PA, 15260, 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; Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA, USA
| | - X Tracy Cui
- Department of Bioengineering, University of Pittsburgh, 5057 Biomedical Science Tower 3, 3501 Fifth Avenue, Pittsburgh, PA, 15260, 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.
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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.
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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
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35
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Prospects for a Robust Cortical Recording Interface. Neuromodulation 2018. [DOI: 10.1016/b978-0-12-805353-9.00028-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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36
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Kim E, Kim JY, Choi H. An SU-8-based microprobe with a nanostructured surface enhances neuronal cell attachment and growth. MICRO AND NANO SYSTEMS LETTERS 2017. [DOI: 10.1186/s40486-017-0062-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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37
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Guo Y, Jiang S, Grena BJB, Kimbrough IF, Thompson EG, Fink Y, Sontheimer H, Yoshinobu T, Jia X. Polymer Composite with Carbon Nanofibers Aligned during Thermal Drawing as a Microelectrode for Chronic Neural Interfaces. ACS NANO 2017; 11:6574-6585. [PMID: 28570813 DOI: 10.1021/acsnano.6b07550] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Microelectrodes provide a direct pathway to investigate brain activities electrically from the external world, which has advanced our fundamental understanding of brain functions and has been utilized for rehabilitative applications as brain-machine interfaces. However, minimizing the tissue response and prolonging the functional durations of these devices remain challenging. Therefore, the development of next-generation microelectrodes as neural interfaces is actively progressing from traditional inorganic materials toward biocompatible and functional organic materials with a miniature footprint, good flexibility, and reasonable robustness. In this study, we developed a miniaturized all polymer-based neural probe with carbon nanofiber (CNF) composites as recording electrodes via the scalable thermal drawing process. We demonstrated that in situ CNF unidirectional alignment can be achieved during the thermal drawing, which contributes to a drastic improvement of electrical conductivity by 2 orders of magnitude compared to a conventional polymer electrode, while still maintaining the mechanical compliance with brain tissues. The resulting neural probe has a miniature footprint, including a recording site with a reduced size comparable to a single neuron and maintained impedance that was able to capture neural activities. Its stable functionality as a chronic implant has been demonstrated with the long-term reliable electrophysiological recording with single-spike resolution and the minimal tissue response over the extended period of implantation in wild-type mice. Technology developed here can be applied to basic chronic electrophysiological studies as well as clinical implementation for neuro-rehabilitative applications.
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Affiliation(s)
- Yuanyuan Guo
- Department of Biomedical Engineering, Tohoku University , Sendai, Miyagi 9808579, Japan
- Bradley Department of Electrical and Computer Engineering, Virginia Polytechnic Institute and State University , Blacksburg, Virginia 24060, United States
| | - Shan Jiang
- Bradley Department of Electrical and Computer Engineering, Virginia Polytechnic Institute and State University , Blacksburg, Virginia 24060, United States
| | - Benjamin J B Grena
- Department of Material Science and Engineering, Massachusetts Institute of Technology , Cambridge, Massachusetts 24139, United States
| | - Ian F Kimbrough
- Virginia Tech Carilion Research Institute , Roanoke, Virginia 14016, United States
| | - Emily G Thompson
- Virginia Tech Carilion Research Institute , Roanoke, Virginia 14016, United States
| | - Yoel Fink
- Department of Material Science and Engineering, Massachusetts Institute of Technology , Cambridge, Massachusetts 24139, United States
| | - Harald Sontheimer
- Virginia Tech Carilion Research Institute , Roanoke, Virginia 14016, United States
| | - Tatsuo Yoshinobu
- Department of Biomedical Engineering, Tohoku University , Sendai, Miyagi 9808579, Japan
| | - Xiaoting Jia
- Bradley Department of Electrical and Computer Engineering, Virginia Polytechnic Institute and State University , Blacksburg, Virginia 24060, United States
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38
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Bioactive interpenetrating polymer networks for improving the electrode/neural-tissue interface. Electrochem commun 2017. [DOI: 10.1016/j.elecom.2017.04.015] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
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39
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Chen R, Canales A, Anikeeva P. Neural Recording and Modulation Technologies. NATURE REVIEWS. MATERIALS 2017; 2:16093. [PMID: 31448131 PMCID: PMC6707077 DOI: 10.1038/natrevmats.2016.93] [Citation(s) in RCA: 289] [Impact Index Per Article: 41.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Within the mammalian nervous system, billions of neurons connected by quadrillions of synapses exchange electrical, chemical and mechanical signals. Disruptions to this network manifest as neurological or psychiatric conditions. Despite decades of neuroscience research, our ability to treat or even to understand these conditions is limited by the tools capable of probing the signalling complexity of the nervous system. Although orders of magnitude smaller and computationally faster than neurons, conventional substrate-bound electronics do not address the chemical and mechanical properties of neural tissue. This mismatch results in a foreign-body response and the encapsulation of devices by glial scars, suggesting that the design of an interface between the nervous system and a synthetic sensor requires additional materials innovation. Advances in genetic tools for manipulating neural activity have fuelled the demand for devices capable of simultaneous recording and controlling individual neurons at unprecedented scales. Recently, flexible organic electronics and bio- and nanomaterials have been developed for multifunctional and minimally invasive probes for long-term interaction with the nervous system. In this Review, we discuss the design lessons from the quarter-century-old field of neural engineering, highlight recent materials-driven progress in neural probes, and look at emergent directions inspired by the principles of neural transduction.
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Affiliation(s)
- Ritchie Chen
- Department of Materials Science and Engineering, and Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Andres Canales
- Department of Materials Science and Engineering, and Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Polina Anikeeva
- Department of Materials Science and Engineering, and Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA, USA
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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.
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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.
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Thompson CH, Zoratti MJ, Langhals NB, Purcell EK. Regenerative Electrode Interfaces for Neural Prostheses. TISSUE ENGINEERING PART B-REVIEWS 2016; 22:125-35. [DOI: 10.1089/ten.teb.2015.0279] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Affiliation(s)
- Cort H. Thompson
- Department of Electrical and Computer Engineering, Neuroscience Program, Michigan State University, East Lansing, Michigan
| | - Marissa J. Zoratti
- Department of Electrical and Computer Engineering, Neuroscience Program, Michigan State University, East Lansing, Michigan
| | - Nicholas B. Langhals
- Department of Electrical and Computer Engineering, Neuroscience Program, Michigan State University, East Lansing, Michigan
| | - Erin K. Purcell
- Department of Electrical and Computer Engineering, Neuroscience Program, Michigan State University, East Lansing, Michigan
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Nguyen JK, Jorfi M, Buchanan KL, Park DJ, Foster EJ, Tyler DJ, Rowan SJ, Weder C, Capadona JR. Influence of resveratrol release on the tissue response to mechanically adaptive cortical implants. Acta Biomater 2016; 29:81-93. [PMID: 26553391 PMCID: PMC4727752 DOI: 10.1016/j.actbio.2015.11.001] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Revised: 10/05/2015] [Accepted: 11/02/2015] [Indexed: 01/10/2023]
Abstract
The stability and longevity of recordings obtained from intracortical microelectrodes continues to remain an area of concern for neural interfacing applications. The limited longevity of microelectrode performance has been associated with the integrity of the blood brain barrier (BBB) and the neuroinflammatory response to the microelectrode. Here, we report the investigation of an additive approach that targets both mechanical and chemical factors believed to contribute to chronic BBB instability and the neuroinflammatory response associated with implanted intracortical microelectrodes. The implants investigated were based on a mechanically adaptive, compliant nanocomposite (NC), which reduces the tissue response and tissue strain. This material was doped with various concentrations of the antioxidant resveratrol with the objective of local and rapid delivery. In vitro analysis of resveratrol release, antioxidant activity, and cytotoxicity suggested that a resveratrol content of 0.01% was optimal for in vivo assessment. Thus, probes made from the neat NC reference and probes containing resveratrol (NC Res) were implanted into the cortical tissue of rats for up to sixteen weeks. Histochemical analysis suggested that at three days post-implantation, neither materials nor therapeutic approaches (independently or in combination) could alter the initial wound healing response. However, at two weeks post-implantation, the NC Res implant showed a reduction in activated microglia/macrophages and improvement in neuron density at the tissue-implant interface when compared to the neat NC reference. However, sixteen weeks post-implantation, when the antioxidant was exhausted, NC Res and the neat NC reference exhibited similar tissue responses. The data show that NC Res provides short-term, short-lived benefits due to the antioxidant release, and a long-term reduction in neuroinflammation on account of is mechanical adaptive, compliant nature. Together, these results demonstrate that local delivery of resveratrol can provide an additive advantage by providing a consistent reduction in the tissue response.
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Affiliation(s)
- Jessica K Nguyen
- Department of Biomedical Engineering, Case Western Reserve University, 2071 Martin Luther King Jr. Drive, Wickenden Bldg, Cleveland, OH 44106, USA; Advanced Platform Technology Center, Louis Stokes Cleveland Department of Veterans Affairs Medical Center, 10701 East Blvd, 151 W/APT, Cleveland, OH 44106-1702, USA
| | - Mehdi Jorfi
- Adolphe Merkle Institute, University of Fribourg, Chemin des Verdiers 4, 1700 Fribourg, Switzerland
| | - Kelly L Buchanan
- Department of Biomedical Engineering, Case Western Reserve University, 2071 Martin Luther King Jr. Drive, Wickenden Bldg, Cleveland, OH 44106, USA; Advanced Platform Technology Center, Louis Stokes Cleveland Department of Veterans Affairs Medical Center, 10701 East Blvd, 151 W/APT, Cleveland, OH 44106-1702, USA
| | - Daniel J Park
- Department of Biomedical Engineering, Case Western Reserve University, 2071 Martin Luther King Jr. Drive, Wickenden Bldg, Cleveland, OH 44106, USA
| | - E Johan Foster
- Adolphe Merkle Institute, University of Fribourg, Chemin des Verdiers 4, 1700 Fribourg, Switzerland; Virginia Tech, Department of Materials Science & Engineering & Macromolecules and Interfaces Institute, 445 Old Turner Street, 213 Holden Hall, Blacksburg, VA 24061, USA
| | - Dustin J Tyler
- Department of Biomedical Engineering, Case Western Reserve University, 2071 Martin Luther King Jr. Drive, Wickenden Bldg, Cleveland, OH 44106, USA; Advanced Platform Technology Center, Louis Stokes Cleveland Department of Veterans Affairs Medical Center, 10701 East Blvd, 151 W/APT, Cleveland, OH 44106-1702, USA
| | - Stuart J Rowan
- Department of Macromolecular Science and Engineering, Case Western Reserve University, 2100 Adelbert Road, Kent Hale Smith Bldg, Cleveland, OH 44106-7202, USA
| | - Christoph Weder
- Adolphe Merkle Institute, University of Fribourg, Chemin des Verdiers 4, 1700 Fribourg, Switzerland
| | - Jeffrey R Capadona
- Department of Biomedical Engineering, Case Western Reserve University, 2071 Martin Luther King Jr. Drive, Wickenden Bldg, Cleveland, OH 44106, USA; Advanced Platform Technology Center, Louis Stokes Cleveland Department of Veterans Affairs Medical Center, 10701 East Blvd, 151 W/APT, Cleveland, OH 44106-1702, USA.
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Alba NA, Du ZJ, Catt KA, Kozai TDY, Cui XT. In Vivo Electrochemical Analysis of a PEDOT/MWCNT Neural Electrode Coating. BIOSENSORS-BASEL 2015; 5:618-46. [PMID: 26473938 PMCID: PMC4697137 DOI: 10.3390/bios5040618] [Citation(s) in RCA: 73] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/18/2015] [Revised: 09/23/2015] [Accepted: 09/30/2015] [Indexed: 12/25/2022]
Abstract
Neural electrodes hold tremendous potential for improving understanding of brain function and restoring lost neurological functions. Multi-walled carbon nanotube (MWCNT) and dexamethasone (Dex)-doped poly(3,4-ethylenedioxythiophene) (PEDOT) coatings have shown promise to improve chronic neural electrode performance. Here, we employ electrochemical techniques to characterize the coating in vivo. Coated and uncoated electrode arrays were implanted into rat visual cortex and subjected to daily cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) for 11 days. Coated electrodes experienced a significant decrease in 1 kHz impedance within the first two days of implantation followed by an increase between days 4 and 7. Equivalent circuit analysis showed that the impedance increase is the result of surface capacitance reduction, likely due to protein and cellular processes encapsulating the porous coating. Coating's charge storage capacity remained consistently higher than uncoated electrodes, demonstrating its in vivo electrochemical stability. To decouple the PEDOT/MWCNT material property changes from the tissue response, in vitro characterization was conducted by soaking the coated electrodes in PBS for 11 days. Some coated electrodes exhibited steady impedance while others exhibiting large increases associated with large decreases in charge storage capacity suggesting delamination in PBS. This was not observed in vivo, as scanning electron microscopy of explants verified the integrity of the coating with no sign of delamination or cracking. Despite the impedance increase, coated electrodes successfully recorded neural activity throughout the implantation period.
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Affiliation(s)
- Nicolas A Alba
- Department of Bioengineering, University of Pittsburgh, 5056 Biomedical Science Tower 3, 3501 Fifth Avenue, Pittsburgh, PA 15213, USA.
- Center for the Neural Basis of Cognition, University of Pittsburgh, Pittsburgh, PA 15260, USA.
- McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA 15260, USA.
| | - Zhanhong J Du
- Department of Bioengineering, University of Pittsburgh, 5056 Biomedical Science Tower 3, 3501 Fifth Avenue, Pittsburgh, PA 15213, USA.
- Center for the Neural Basis of Cognition, University of Pittsburgh, Pittsburgh, PA 15260, USA.
- McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA 15260, USA.
| | - Kasey A Catt
- Department of Bioengineering, University of Pittsburgh, 5056 Biomedical Science Tower 3, 3501 Fifth Avenue, Pittsburgh, PA 15213, USA.
| | - Takashi D Y Kozai
- Department of Bioengineering, University of Pittsburgh, 5056 Biomedical Science Tower 3, 3501 Fifth Avenue, Pittsburgh, PA 15213, USA.
- Center for the Neural Basis of Cognition, University of Pittsburgh, Pittsburgh, PA 15260, USA.
- McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA 15260, USA.
- NeuroTech Center of the University of Pittsburgh Brain Institute, Pittsburgh, PA 15260, USA.
| | - X Tracy Cui
- Department of Bioengineering, University of Pittsburgh, 5056 Biomedical Science Tower 3, 3501 Fifth Avenue, Pittsburgh, PA 15213, USA.
- Center for the Neural Basis of Cognition, University of Pittsburgh, Pittsburgh, PA 15260, USA.
- McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA 15260, USA.
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Patel PR, Na K, Zhang H, Kozai TDY, Kotov NA, Yoon E, Chestek CA. Insertion of linear 8.4 μm diameter 16 channel carbon fiber electrode arrays for single unit recordings. J Neural Eng 2015; 12:046009. [PMID: 26035638 PMCID: PMC4789140 DOI: 10.1088/1741-2560/12/4/046009] [Citation(s) in RCA: 98] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
OBJECTIVE Single carbon fiber electrodes (d = 8.4 μm) insulated with parylene-c and functionalized with PEDOT pTS have been shown to record single unit activity but manual implantation of these devices with forceps can be difficult. Without an improvement in the insertion method any increase in the channel count by fabricating carbon fiber arrays would be impractical. In this study, we utilize a water soluble coating and structural backbones that allow us to create, implant, and record from fully functionalized arrays of carbon fibers with ∼150 μm pitch. APPROACH Two approaches were tested for the insertion of carbon fiber arrays. The first method used a poly(ethylene glycol) (PEG) coating that temporarily stiffened the fibers while leaving a small portion at the tip exposed. The small exposed portion (500 μm-1 mm) readily penetrated the brain allowing for an insertion that did not require the handling of each fiber by forceps. The second method involved the fabrication of silicon support structures with individual shanks spaced 150 μm apart. Each shank consisted of a small groove that held an individual carbon fiber. MAIN RESULTS Our results showed that the PEG coating allowed for the chronic implantation of carbon fiber arrays in five rats with unit activity detected at 31 days post-implant. The silicon support structures recorded single unit activity in three acute rat surgeries. In one of those surgeries a stacked device with three layers of silicon support structures and carbon fibers was built and shown to readily insert into the brain with unit activity on select sites. SIGNIFICANCE From these studies we have found that carbon fibers spaced at ∼150 μm readily insert into the brain. This greatly increases the recording density of chronic neural probes and paves the way for even higher density devices that have a minimal scarring response.
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Affiliation(s)
- Paras R Patel
- Department of Biomedical Engineering, College of Engineering, University of Michigan, USA
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Kolarcik CL, Luebben SD, Sapp SA, Hanner J, Snyder N, Kozai TDY, Chang E, Nabity JA, Nabity ST, Lagenaur CF, Cui XT. Elastomeric and soft conducting microwires for implantable neural interfaces. SOFT MATTER 2015; 11:4847-61. [PMID: 25993261 PMCID: PMC4466039 DOI: 10.1039/c5sm00174a] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Current designs for microelectrodes used for interfacing with the nervous system elicit a characteristic inflammatory response that leads to scar tissue encapsulation, electrical insulation of the electrode from the tissue and ultimately failure. Traditionally, relatively stiff materials like tungsten and silicon are employed which have mechanical properties several orders of magnitude different from neural tissue. This mechanical mismatch is thought to be a major cause of chronic inflammation and degeneration around the device. In an effort to minimize the disparity between neural interface devices and the brain, novel soft electrodes consisting of elastomers and intrinsically conducting polymers were fabricated. The physical, mechanical and electrochemical properties of these materials were extensively characterized to identify the formulations with the optimal combination of parameters including Young's modulus, elongation at break, ultimate tensile strength, conductivity, impedance and surface charge injection. Our final electrode has a Young's modulus of 974 kPa which is five orders of magnitude lower than tungsten and significantly lower than other polymer-based neural electrode materials. In vitro cell culture experiments demonstrated the favorable interaction between these soft materials and neurons, astrocytes and microglia, with higher neuronal attachment and a two-fold reduction in inflammatory microglia attachment on soft devices compared to stiff controls. Surface immobilization of neuronal adhesion proteins on these microwires further improved the cellular response. Finally, in vivo electrophysiology demonstrated the functionality of the elastomeric electrodes in recording single unit activity in the rodent visual cortex. The results presented provide initial evidence in support of the use of soft materials in neural interface applications.
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Affiliation(s)
- Christi L Kolarcik
- Department of Bioengineering, University of Pittsburgh, 5057 Biomedical Science Tower 3, 3501 Fifth Avenue, Pittsburgh, PA, USA.
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Gunasekera B, Saxena T, Bellamkonda R, Karumbaiah L. Intracortical recording interfaces: current challenges to chronic recording function. ACS Chem Neurosci 2015; 6:68-83. [PMID: 25587704 DOI: 10.1021/cn5002864] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Brain Computer Interfaces (BCIs) offer significant hope to tetraplegic and paraplegic individuals. This technology relies on extracting and translating motor intent to facilitate control of a computer cursor or to enable fine control of an external assistive device such as a prosthetic limb. Intracortical recording interfaces (IRIs) are critical components of BCIs and consist of arrays of penetrating electrodes that are implanted into the motor cortex of the brain. These multielectrode arrays (MEAs) are responsible for recording and conducting neural signals from local ensembles of neurons in the motor cortex with the high speed and spatiotemporal resolution that is required for exercising control of external assistive prostheses. Recent design and technological innovations in the field have led to significant improvements in BCI function. However, long-term (chronic) BCI function is severely compromised by short-term (acute) IRI recording failure. In this review, we will discuss the design and function of current IRIs. We will also review a host of recent advances that contribute significantly to our overall understanding of the cellular and molecular events that lead to acute recording failure of these invasive implants. We will also present recent improvements to IRI design and provide insights into the futuristic design of more chronically functional IRIs.
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Affiliation(s)
- Bhagya Gunasekera
- Regenerative
Bioscience Center, ADS Complex, The University of Georgia, Athens, Georgia 30602-2771, United States
| | - Tarun Saxena
- Wallace
H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332-0535, United States
| | - Ravi Bellamkonda
- Wallace
H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332-0535, United States
| | - Lohitash Karumbaiah
- Regenerative
Bioscience Center, ADS Complex, The University of Georgia, Athens, Georgia 30602-2771, United States
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Jorfi M, Skousen JL, Weder C, Capadona JR. Progress towards biocompatible intracortical microelectrodes for neural interfacing applications. J Neural Eng 2014; 12:011001. [PMID: 25460808 DOI: 10.1088/1741-2560/12/1/011001] [Citation(s) in RCA: 218] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
To ensure long-term consistent neural recordings, next-generation intracortical microelectrodes are being developed with an increased emphasis on reducing the neuro-inflammatory response. The increased emphasis stems from the improved understanding of the multifaceted role that inflammation may play in disrupting both biologic and abiologic components of the overall neural interface circuit. To combat neuro-inflammation and improve recording quality, the field is actively progressing from traditional inorganic materials towards approaches that either minimizes the microelectrode footprint or that incorporate compliant materials, bioactive molecules, conducting polymers or nanomaterials. However, the immune-privileged cortical tissue introduces an added complexity compared to other biomedical applications that remains to be fully understood. This review provides a comprehensive reflection on the current understanding of the key failure modes that may impact intracortical microelectrode performance. In addition, a detailed overview of the current status of various materials-based approaches that have gained interest for neural interfacing applications is presented, and key challenges that remain to be overcome are discussed. Finally, we present our vision on the future directions of materials-based treatments to improve intracortical microelectrodes for neural interfacing.
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Affiliation(s)
- Mehdi Jorfi
- Adolphe Merkle Institute, University of Fribourg, Rte de l'Ancienne Papeterie, CH-1723 Marly, Switzerland
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Sommakia S, Lee HC, Gaire J, Otto KJ. Materials approaches for modulating neural tissue responses to implanted microelectrodes through mechanical and biochemical means. CURRENT OPINION IN SOLID STATE & MATERIALS SCIENCE 2014; 18:319-328. [PMID: 25530703 PMCID: PMC4267064 DOI: 10.1016/j.cossms.2014.07.005] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Implantable intracortical microelectrodes face an uphill struggle for widespread clinical use. Their potential for treating a wide range of traumatic and degenerative neural disease is hampered by their unreliability in chronic settings. A major factor in this decline in chronic performance is a reactive response of brain tissue, which aims to isolate the implanted device from the rest of the healthy tissue. In this review we present a discussion of materials approaches aimed at modulating the reactive tissue response through mechanical and biochemical means. Benefits and challenges associated with these approaches are analyzed, and the importance of multimodal solutions tested in emerging animal models are presented.
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Affiliation(s)
- Salah Sommakia
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN 47907-1791
| | - Heui C. Lee
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN 47907-1791
| | - Janak Gaire
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47907-1791
| | - Kevin J. Otto
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN 47907-1791
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47907-1791
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Tran CT, Kondyurin A, Chrzanowski W, Bilek MM, McKenzie DR. Increasing binding density of yeast cells by control of surface charge with allylamine grafting to ion modified polymer surfaces. Colloids Surf B Biointerfaces 2014; 122:537-544. [DOI: 10.1016/j.colsurfb.2014.07.026] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2014] [Revised: 06/20/2014] [Accepted: 07/15/2014] [Indexed: 10/25/2022]
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