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Vara H, Hernández-Labrado GR, Alves-Sampaio A, Collazos-Castro JE. Stability of Conducting Polymer-Coated Carbon Microfibers for Long-Term Electrical Stimulation of Injured Neural Tissue. Polymers (Basel) 2024; 16:2093. [PMID: 39065410 PMCID: PMC11280860 DOI: 10.3390/polym16142093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2024] [Revised: 07/12/2024] [Accepted: 07/18/2024] [Indexed: 07/28/2024] Open
Abstract
Electroactive microfiber-based scaffolds aid neural tissue repair. Carbon microfibers (CMFs) coated with the conducting polymer poly(3,4-ethylenedioxythiophene) doped with poly[(4-styrenesulfonic acid)-co-(maleic acid)] (PEDOT:PSS-co-MA) provide efficient support and guidance to regrowing axons across spinal cord lesions in rodents and pigs. We investigated the electrical and structural performance of PEDOT:PSS-co-MA-coated carbon MFs (PCMFs) for long-term, biphasic electrical stimulation (ES). Chronopotentiometry and electrochemical impedance spectroscopy (EIS) allowed the characterization of charge transfer in PCMFs during ES in vitro, and morphological changes were assessed by scanning electron microscopy (SEM). PCMFs that were 4 mm long withstood two-million-biphasic pulses without reaching cytotoxic voltages, with a 6 mm length producing optimal results. Although EIS and SEM unveiled some polymer deterioration in the 6 mm PCMFs, no significant changes in voltage excursions appeared. For the preliminary testing of the electrical performance of PCMFs in vivo, we used 12 mm long, 20-microfiber assemblies interconnected by metallic microwires. PCMFs-assemblies were implanted in two spinal cord-injured pigs and submitted to ES for 10 days. A cobalt-alloy interconnected assembly showed safe voltages for about 1.5 million-pulses and was electrically functional at 1-month post-implantation, suggesting its suitability for sub-chronic ES, as likely required for spinal cord repair. However, improving polymer adhesion to the carbon substrate is still needed to use PCMFs for prolonged ES.
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Affiliation(s)
- Hugo Vara
- Neural Repair and Biomaterials Laboratory, Hospital Nacional de Parapléjicos (SESCAM), Finca la Peraleda S-N, 45071 Toledo, Spain; (H.V.); (A.A.-S.)
| | - Gabriel Raúl Hernández-Labrado
- Escuela de Ingeniería Industrial y Aeroespacial, Universidad de Castilla-La Mancha, Avda. Carlos III, 45071 Toledo, Spain;
| | - Alexandra Alves-Sampaio
- Neural Repair and Biomaterials Laboratory, Hospital Nacional de Parapléjicos (SESCAM), Finca la Peraleda S-N, 45071 Toledo, Spain; (H.V.); (A.A.-S.)
| | - Jorge E. Collazos-Castro
- Neural Repair and Biomaterials Laboratory, Hospital Nacional de Parapléjicos (SESCAM), Finca la Peraleda S-N, 45071 Toledo, Spain; (H.V.); (A.A.-S.)
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2
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Sun Y, Xiao Z, Chen B, Zhao Y, Dai J. Advances in Material-Assisted Electromagnetic Neural Stimulation. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024; 36:e2400346. [PMID: 38594598 DOI: 10.1002/adma.202400346] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2024] [Revised: 03/26/2024] [Indexed: 04/11/2024]
Abstract
Bioelectricity plays a crucial role in organisms, being closely connected to neural activity and physiological processes. Disruptions in the nervous system can lead to chaotic ionic currents at the injured site, causing disturbances in the local cellular microenvironment, impairing biological pathways, and resulting in a loss of neural functions. Electromagnetic stimulation has the ability to generate internal currents, which can be utilized to counter tissue damage and aid in the restoration of movement in paralyzed limbs. By incorporating implanted materials, electromagnetic stimulation can be targeted more accurately, thereby significantly improving the effectiveness and safety of such interventions. Currently, there have been significant advancements in the development of numerous promising electromagnetic stimulation strategies with diverse materials. This review provides a comprehensive summary of the fundamental theories, neural stimulation modulating materials, material application strategies, and pre-clinical therapeutic effects associated with electromagnetic stimulation for neural repair. It offers a thorough analysis of current techniques that employ materials to enhance electromagnetic stimulation, as well as potential therapeutic strategies for future applications.
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Affiliation(s)
- Yuting Sun
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Zhifeng Xiao
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Bing Chen
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Yannan Zhao
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Jianwu Dai
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
- Tianjin Key Laboratory of Biomedical Materials, Institute of Biomedical Engineering, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin, 300192, China
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3
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Alves-Sampaio A, Del-Cerro P, Collazos-Castro JE. Composite Fibrin/Carbon Microfiber Implants for Bridging Spinal Cord Injury: A Translational Approach in Pigs. Int J Mol Sci 2023; 24:11102. [PMID: 37446280 DOI: 10.3390/ijms241311102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Revised: 06/29/2023] [Accepted: 07/02/2023] [Indexed: 07/15/2023] Open
Abstract
Biomaterials may enhance neural repair after spinal cord injury (SCI) and testing their functionality in large animals is essential to achieve successful clinical translation. This work developed a porcine contusion/compression SCI model to investigate the consequences of myelotomy and implantation of fibrin gel containing biofunctionalized carbon microfibers (MFs). Fourteen pigs were distributed in SCI, SCI/myelotomy, and SCI/myelotomy/implant groups. An automated device was used for SCI. A dorsal myelotomy was performed on the lesion site at 1 day post-injury for removing cloths and devitalized tissue. Bundles of MFs coated with a conducting polymer and cell adhesion molecules were embedded in fibrin gel and used to bridge the spinal cord cavity. Reproducible lesions of about 1 cm in length were obtained. Myelotomy and lesion debridement caused no further neural damage compared to SCI alone but had little positive effect on neural regrowth. The MFs/fibrin gel implant facilitated axonal sprouting, elongation, and alignment within the lesion. However, the implant also increased lesion volume and was ineffective in preventing fibrosis, thus precluding functional neural regeneration. Our results indicate that myelotomy and lesion debridement can be advantageously used for implanting MF-based scaffolds. However, the implants need refinement and pharmaceuticals will be necessary to limit scarring.
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Affiliation(s)
- Alexandra Alves-Sampaio
- Neural Repair and Biomaterials Laboratory, Hospital Nacional de Parapléjicos (SESCAM), Finca La Peraleda S-N, 45071 Toledo, Spain
| | - Patricia Del-Cerro
- Neural Repair and Biomaterials Laboratory, Hospital Nacional de Parapléjicos (SESCAM), Finca La Peraleda S-N, 45071 Toledo, Spain
| | - Jorge E Collazos-Castro
- Neural Repair and Biomaterials Laboratory, Hospital Nacional de Parapléjicos (SESCAM), Finca La Peraleda S-N, 45071 Toledo, Spain
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4
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Composite Fibrin and Carbon Microfibre Implant to Modulate Postraumatic Inflammation after Spinal Cord Injury. Cells 2023; 12:cells12060839. [PMID: 36980180 PMCID: PMC10047285 DOI: 10.3390/cells12060839] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Revised: 03/02/2023] [Accepted: 03/05/2023] [Indexed: 03/11/2023] Open
Abstract
Poor functional recovery after spinal cord injury (SCI) drives the development of novel strategies to manage this devastating condition. We recently showed promising immunomodulatory and pro-regenerative actions of bio-functionalized carbon microfibres (MFs) implanted in a rodent model of SCI. In order to maximize tissue repair while easing MF implantation, we produced a composite implant based on the embedding of several MFs within a fibrin hydrogel. We used intravital imaging of fluorescent reporter mice at the early stages and spinal sections of the same animals 3 months later to characterize the neuroinflammatory response to the implant and its impact on axonal regeneration. Whereas fibrin alone was inert in the first week, its enzymatic degradation drove the chronic activation of microglial cells and axonal degeneration within 3 months. However, the presence of MFs inside the fibrin hydrogel slowed down fibrin degradation and boosted the early recruitment of immune cells. Noteworthy, there was an enhanced contribution of monocyte-derived dendritic cells (moDCs), preceding a faster transition toward an anti-inflammatory environment with increased axonal regeneration over 3 months. The inclusion of MF here ensured the long-term biocompatibility of fibrin hydrogels, which would otherwise preclude successful spinal cord regeneration.
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Sun F, Jiang H, Wang H, Zhong Y, Xu Y, Xing Y, Yu M, Feng LW, Tang Z, Liu J, Sun H, Wang H, Wang G, Zhu M. Soft Fiber Electronics Based on Semiconducting Polymer. Chem Rev 2023; 123:4693-4763. [PMID: 36753731 DOI: 10.1021/acs.chemrev.2c00720] [Citation(s) in RCA: 19] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
Abstract
Fibers, originating from nature and mastered by human, have woven their way throughout the entire history of human civilization. Recent developments in semiconducting polymer materials have further endowed fibers and textiles with various electronic functions, which are attractive in applications such as information interfacing, personalized medicine, and clean energy. Owing to their ability to be easily integrated into daily life, soft fiber electronics based on semiconducting polymers have gained popularity recently for wearable and implantable applications. Herein, we present a review of the previous and current progress in semiconducting polymer-based fiber electronics, particularly focusing on smart-wearable and implantable areas. First, we provide a brief overview of semiconducting polymers from the viewpoint of materials based on the basic concepts and functionality requirements of different devices. Then we analyze the existing applications and associated devices such as information interfaces, healthcare and medicine, and energy conversion and storage. The working principle and performance of semiconducting polymer-based fiber devices are summarized. Furthermore, we focus on the fabrication techniques of fiber devices. Based on the continuous fabrication of one-dimensional fiber and yarn, we introduce two- and three-dimensional fabric fabricating methods. Finally, we review challenges and relevant perspectives and potential solutions to address the related problems.
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Affiliation(s)
- Fengqiang Sun
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University, Shanghai 201620, China
- Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China
| | - Hao Jiang
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University, Shanghai 201620, China
| | - Haoyu Wang
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University, Shanghai 201620, China
| | - Yueheng Zhong
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University, Shanghai 201620, China
| | - Yiman Xu
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University, Shanghai 201620, China
| | - Yi Xing
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University, Shanghai 201620, China
| | - Muhuo Yu
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University, Shanghai 201620, China
- Shanghai Key Laboratory of Lightweight Structural Composites, College of Materials Science and Engineering, Donghua University, Shanghai 201620, China
| | - Liang-Wen Feng
- Key Laboratory of Green Chemistry & Technology, Ministry of Education, College of Chemistry, Sichuan University, Chengdu 610065, China
| | - Zheng Tang
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University, Shanghai 201620, China
- Center for Advanced Low-dimension Materials, Donghua University, Shanghai 201620, China
| | - Jun Liu
- National Key Laboratory on Electromagnetic Environment Effects and Electro-Optical Engineering, Nanjing 210007, China
| | - Hengda Sun
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University, Shanghai 201620, China
| | - Hongzhi Wang
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University, Shanghai 201620, China
| | - Gang Wang
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University, Shanghai 201620, China
| | - Meifang Zhu
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University, Shanghai 201620, China
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Bandres MF, Gomes JL, McPherson JG. Spinal stimulation for motor rehabilitation immediately modulates nociceptive transmission. J Neural Eng 2022; 19:10.1088/1741-2552/ac9a00. [PMID: 36228593 PMCID: PMC9797038 DOI: 10.1088/1741-2552/ac9a00] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Accepted: 10/13/2022] [Indexed: 12/31/2022]
Abstract
Objective. Spinal cord injury (SCI) often results in debilitating movement impairments and neuropathic pain. Electrical stimulation of spinal neurons holds considerable promise both for enhancing neural transmission in weakened motor pathways and for reducing neural transmission in overactive nociceptive pathways. However, spinal stimulation paradigms currently under development for individuals living with SCI continue overwhelmingly to be developed in the context of motor rehabilitation alone. The objective of this study is to test the hypothesis that motor-targeted spinal stimulation simultaneously modulates spinal nociceptive transmission.Approach. We characterized the neuromodulatory actions of motor-targeted intraspinal microstimulation (ISMS) on the firing dynamics of large populations of discrete nociceptive specific and wide dynamic range (WDR) neurons. Neurons were accessed via dense microelectrode arrays implantedin vivointo lumbar enlargement of rats. Nociceptive and non-nociceptive cutaneous transmission was induced before, during, and after ISMS by mechanically probing the L5 dermatome.Main results. Our primary findings are that (a) sub-motor threshold ISMS delivered to spinal motor pools immediately modulates concurrent nociceptive transmission; (b) the magnitude of anti-nociceptive effects increases with longer durations of ISMS, including robust carryover effects; (c) the majority of all identified nociceptive-specific and WDR neurons exhibit firing rate reductions after only 10 min of ISMS; and (d) ISMS does not increase spinal responsiveness to non-nociceptive cutaneous transmission. These results lead to the conclusion that ISMS parameterized to enhance motor output results in an overall net decrease n spinal nociceptive transmission.Significance. These results suggest that ISMS may hold translational potential for neuropathic pain-related applications and that it may be uniquely suited to delivering multi-modal therapeutic benefits for individuals living with SCI.
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Affiliation(s)
- Maria F. Bandres
- Program in Physical Therapy, Washington University School of Medicine in St. Louis
- Department of Biomedical Engineering; Washington University in St. Louis
| | - Jefferson L. Gomes
- Program in Physical Therapy, Washington University School of Medicine in St. Louis
| | - Jacob G. McPherson
- Program in Physical Therapy, Washington University School of Medicine in St. Louis
- Department of Anesthesiology, Washington University School of Medicine in St. Louis
- Washington University Pain Center, Washington University School of Medicine in St. Louis
- Program in Neuroscience; Washington University School of Medicine in St. Louis
- Department of Biomedical Engineering; Washington University in St. Louis
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7
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Xiong Y, Dai X, Liu Y, Du C, Yu G, Xia Y. Insights into highly effective catalytic persulfate activation on oxygen-functionalized mesoporous carbon for ciprofloxacin degradation. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:59013-59026. [PMID: 35380323 DOI: 10.1007/s11356-022-19670-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2021] [Accepted: 03/08/2022] [Indexed: 06/14/2023]
Abstract
Nanocarbons have been demonstrated as promising carbon catalysts for substituting metal-based catalysts for the green treatment of wastewater. In this study, oxygen-functionalized mesoporous carbon (OCMK-3) was prepared by wet oxidation and exhibited high catalytic performance against ciprofloxacin (CIP) by activation of persulfate. The effects of environmental parameters (pH, temperature, coexisting ions) and process parameters (temperature, sodium persulfate concentration, catalyst agent dosage, initial concentration) on the removal of CIP were investigated. Compared with the pristine ordered mesoporous carbon (CMK-3), the removal efficiency of CIP by OCMK-3 was increased by 32% under optimal conditions. This rise in activity was attributed to the increase in oxygen-containing functional groups, porosity, and specific surface area of OCMK-3 with improved structural defects and electron transfer efficiency. Furthermore, based on active species scavenging experiments, a dual-pathway mechanism of the radical and nonradical pathways was discovered. The rational degradation pathway of CIP was investigated based on liquid chromatography-mass spectrometry (LC-MS). In addition, the OCMK-3/PS system exhibited high decomposition efficiency in pharmaceutical wastewater treatment. This study provides an in-depth mechanism for the degradation of organic pollutants by carbon-based PS-AOPs and provides theoretical support for further studies.
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Affiliation(s)
- Ying Xiong
- School of Hydraulic and Environmental Engineering, Changsha University of Science & Technology, Changsha, 410114, China
- Key Laboratory of Dongting Lake Aquatic Eco-Environmental Control and Restoration of Hunan Province, Changsha, 410114, China
- Research Center of Resource Environment and Urban Planning, Changsha University of Science and Technology, Changsha, 410114, Hunan, China
| | - Xiaolei Dai
- School of Hydraulic and Environmental Engineering, Changsha University of Science & Technology, Changsha, 410114, China
| | - Yuanyuan Liu
- Research Center of Resource Environment and Urban Planning, Changsha University of Science and Technology, Changsha, 410114, Hunan, China.
| | - Chunyan Du
- School of Hydraulic and Environmental Engineering, Changsha University of Science & Technology, Changsha, 410114, China
- Key Laboratory of Dongting Lake Aquatic Eco-Environmental Control and Restoration of Hunan Province, Changsha, 410114, China
- Engineering and Technical Center of Hunan Provincial Environmental Protection for River-Lake Dredging Pollution Control, Changsha, 410114, China
| | - Guanlong Yu
- School of Hydraulic and Environmental Engineering, Changsha University of Science & Technology, Changsha, 410114, China
- Key Laboratory of Dongting Lake Aquatic Eco-Environmental Control and Restoration of Hunan Province, Changsha, 410114, China
- Engineering and Technical Center of Hunan Provincial Environmental Protection for River-Lake Dredging Pollution Control, Changsha, 410114, China
| | - Yan Xia
- School of Hydraulic and Environmental Engineering, Changsha University of Science & Technology, Changsha, 410114, China
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Bianchi M, De Salvo A, Asplund M, Carli S, Di Lauro M, Schulze‐Bonhage A, Stieglitz T, Fadiga L, Biscarini F. Poly(3,4-ethylenedioxythiophene)-Based Neural Interfaces for Recording and Stimulation: Fundamental Aspects and In Vivo Applications. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2022; 9:e2104701. [PMID: 35191224 PMCID: PMC9036021 DOI: 10.1002/advs.202104701] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Revised: 01/04/2022] [Indexed: 05/29/2023]
Abstract
Next-generation neural interfaces for bidirectional communication with the central nervous system aim to achieve the intimate integration with the neural tissue with minimal neuroinflammatory response, high spatio-temporal resolution, very high sensitivity, and readout stability. The design and manufacturing of devices for low power/low noise neural recording and safe and energy-efficient stimulation that are, at the same time, conformable to the brain, with matched mechanical properties and biocompatibility, is a convergence area of research where neuroscientists, materials scientists, and nanotechnologists operate synergically. The biotic-abiotic neural interface, however, remains a formidable challenge that prompts for new materials platforms and innovation in device layouts. Conductive polymers (CP) are attractive materials to be interfaced with the neural tissue and to be used as sensing/stimulating electrodes because of their mixed ionic-electronic conductivity, their low contact impedance, high charge storage capacitance, chemical versatility, and biocompatibility. This manuscript reviews the state-of-the-art of poly(3,4-ethylenedioxythiophene)-based neural interfaces for extracellular recording and stimulation, focusing on those technological approaches that are successfully demonstrated in vivo. The aim is to highlight the most reliable and ready-for-clinical-use solutions, in terms of materials technology and recording performance, other than spot major limitations and identify future trends in this field.
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Affiliation(s)
- Michele Bianchi
- Center for Translational Neurophysiology of Speech and CommunicationFondazione Istituto Italiano di Tecnologiavia Fossato di Mortara 17Ferrara44121Italy
| | - Anna De Salvo
- Center for Translational Neurophysiology of Speech and CommunicationFondazione Istituto Italiano di Tecnologiavia Fossato di Mortara 17Ferrara44121Italy
- Sezione di FisiologiaUniversità di Ferraravia Fossato di Mortara 17Ferrara44121Italy
| | - Maria Asplund
- Division of Nursing and Medical TechnologyLuleå University of TechnologyLuleå971 87Sweden
- Department of Microsystems Engineering‐IMTEKUniversity of FreiburgFreiburg79110Germany
- BrainLinks‐BrainTools CenterUniversity of FreiburgFreiburg79110Germany
| | - Stefano Carli
- Center for Translational Neurophysiology of Speech and CommunicationFondazione Istituto Italiano di Tecnologiavia Fossato di Mortara 17Ferrara44121Italy
- Present address:
Department of Environmental and Prevention SciencesUniversità di FerraraFerrara44121Italy
| | - Michele Di Lauro
- Center for Translational Neurophysiology of Speech and CommunicationFondazione Istituto Italiano di Tecnologiavia Fossato di Mortara 17Ferrara44121Italy
| | - Andreas Schulze‐Bonhage
- BrainLinks‐BrainTools CenterUniversity of FreiburgFreiburg79110Germany
- Epilepsy CenterFaculty of MedicineUniversity of FreiburgFreiburg79110Germany
| | - Thomas Stieglitz
- Department of Microsystems Engineering‐IMTEKUniversity of FreiburgFreiburg79110Germany
- BrainLinks‐BrainTools CenterUniversity of FreiburgFreiburg79110Germany
| | - Luciano Fadiga
- Center for Translational Neurophysiology of Speech and CommunicationFondazione Istituto Italiano di Tecnologiavia Fossato di Mortara 17Ferrara44121Italy
- Sezione di FisiologiaUniversità di Ferraravia Fossato di Mortara 17Ferrara44121Italy
| | - Fabio Biscarini
- Center for Translational Neurophysiology of Speech and CommunicationFondazione Istituto Italiano di Tecnologiavia Fossato di Mortara 17Ferrara44121Italy
- Life Science DepartmentUniversità di Modena e Reggio EmiliaVia Campi 103Modena41125Italy
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Berggren M, Głowacki ED, Simon DT, Stavrinidou E, Tybrandt K. In Vivo Organic Bioelectronics for Neuromodulation. Chem Rev 2022; 122:4826-4846. [PMID: 35050623 PMCID: PMC8874920 DOI: 10.1021/acs.chemrev.1c00390] [Citation(s) in RCA: 40] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Indexed: 01/27/2023]
Abstract
The nervous system poses a grand challenge for integration with modern electronics and the subsequent advances in neurobiology, neuroprosthetics, and therapy which would become possible upon such integration. Due to its extreme complexity, multifaceted signaling pathways, and ∼1 kHz operating frequency, modern complementary metal oxide semiconductor (CMOS) based electronics appear to be the only technology platform at hand for such integration. However, conventional CMOS-based electronics rely exclusively on electronic signaling and therefore require an additional technology platform to translate electronic signals into the language of neurobiology. Organic electronics are just such a technology platform, capable of converting electronic addressing into a variety of signals matching the endogenous signaling of the nervous system while simultaneously possessing favorable material similarities with nervous tissue. In this review, we introduce a variety of organic material platforms and signaling modalities specifically designed for this role as "translator", focusing especially on recent implementation in in vivo neuromodulation. We hope that this review serves both as an informational resource and as an encouragement and challenge to the field.
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Affiliation(s)
- Magnus Berggren
- Laboratory
of Organic Electronics, Department of Science and Technology, Linköping University, 601 74 Norrköping, Sweden
| | - Eric D. Głowacki
- Laboratory
of Organic Electronics, Department of Science and Technology, Linköping University, 601 74 Norrköping, Sweden
- Bioelectronics
Materials and Devices, Central European
Institute of Technology, Brno University of Technology, Purkyňova 656/123, 612 00 Brno, Czech
Republic
| | - Daniel T. Simon
- Laboratory
of Organic Electronics, Department of Science and Technology, Linköping University, 601 74 Norrköping, Sweden
| | - Eleni Stavrinidou
- Laboratory
of Organic Electronics, Department of Science and Technology, Linköping University, 601 74 Norrköping, Sweden
| | - Klas Tybrandt
- Laboratory
of Organic Electronics, Department of Science and Technology, Linköping University, 601 74 Norrköping, Sweden
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10
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Vėbraitė I, Hanein Y. Soft Devices for High-Resolution Neuro-Stimulation: The Interplay Between Low-Rigidity and Resolution. FRONTIERS IN MEDICAL TECHNOLOGY 2022; 3:675744. [PMID: 35047928 PMCID: PMC8757739 DOI: 10.3389/fmedt.2021.675744] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Accepted: 05/14/2021] [Indexed: 12/27/2022] Open
Abstract
The field of neurostimulation has evolved over the last few decades from a crude, low-resolution approach to a highly sophisticated methodology entailing the use of state-of-the-art technologies. Neurostimulation has been tested for a growing number of neurological applications, demonstrating great promise and attracting growing attention in both academia and industry. Despite tremendous progress, long-term stability of the implants, their large dimensions, their rigidity and the methods of their introduction and anchoring to sensitive neural tissue remain challenging. The purpose of this review is to provide a concise introduction to the field of high-resolution neurostimulation from a technological perspective and to focus on opportunities stemming from developments in materials sciences and engineering to reduce device rigidity while optimizing electrode small dimensions. We discuss how these factors may contribute to smaller, lighter, softer and higher electrode density devices.
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Affiliation(s)
- Ieva Vėbraitė
- School of Electrical Engineering, Tel Aviv University, Tel Aviv, Israel
| | - Yael Hanein
- School of Electrical Engineering, Tel Aviv University, Tel Aviv, Israel
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11
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Zheng XS, Tan C, Castagnola E, Cui XT. Electrode Materials for Chronic Electrical Microstimulation. Adv Healthc Mater 2021; 10:e2100119. [PMID: 34029008 PMCID: PMC8257249 DOI: 10.1002/adhm.202100119] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Revised: 04/20/2021] [Indexed: 02/06/2023]
Abstract
Electrical microstimulation has enabled partial restoration of vision, hearing, movement, somatosensation, as well as improving organ functions by electrically modulating neural activities. However, chronic microstimulation is faced with numerous challenges. The implantation of an electrode array into the neural tissue triggers an inflammatory response, which can be exacerbated by the delivery of electrical currents. Meanwhile, prolonged stimulation may lead to electrode material degradation., which can be accelerated by the hostile inflammatory environment. Both material degradation and adverse tissue reactions can compromise stimulation performance over time. For stable chronic electrical stimulation, an ideal microelectrode must present 1) high charge injection limit, to efficiently deliver charge without exceeding safety limits for both tissue and electrodes, 2) small size, to gain high spatial selectivity, 3) excellent biocompatibility that ensures tissue health immediately next to the device, and 4) stable in vivo electrochemical properties over the application period. In this review, the challenges in chronic microstimulation are described in detail. To aid material scientists interested in neural stimulation research, the in vitro and in vivo testing methods are introduced for assessing stimulation functionality and longevity and a detailed overview of recent advances in electrode material research and device fabrication for improving chronic microstimulation performance is provided.
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Affiliation(s)
- Xin Sally Zheng
- Department of Bioengineering, University of Pittsburgh, 3501 Fifth Ave. Pittsburgh, Pittsburgh, PA, 15213, USA
| | - Chao Tan
- Department of Bioengineering, University of Pittsburgh, 3501 Fifth Ave. Pittsburgh, Pittsburgh, PA, 15213, USA
| | - Elisa Castagnola
- Department of Bioengineering, University of Pittsburgh, 3501 Fifth Ave. Pittsburgh, Pittsburgh, PA, 15213, USA
| | - Xinyan Tracy Cui
- Department of Bioengineering, University of Pittsburgh, 3501 Fifth Ave. Pittsburgh, Pittsburgh, PA, 15213, USA
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Hejazi M, Tong W, Ibbotson MR, Prawer S, Garrett DJ. Advances in Carbon-Based Microfiber Electrodes for Neural Interfacing. Front Neurosci 2021; 15:658703. [PMID: 33912007 PMCID: PMC8072048 DOI: 10.3389/fnins.2021.658703] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Accepted: 03/22/2021] [Indexed: 12/20/2022] Open
Abstract
Neural interfacing devices using penetrating microelectrode arrays have emerged as an important tool in both neuroscience research and medical applications. These implantable microelectrode arrays enable communication between man-made devices and the nervous system by detecting and/or evoking neuronal activities. Recent years have seen rapid development of electrodes fabricated using flexible, ultrathin carbon-based microfibers. Compared to electrodes fabricated using rigid materials and larger cross-sections, these microfiber electrodes have been shown to reduce foreign body responses after implantation, with improved signal-to-noise ratio for neural recording and enhanced resolution for neural stimulation. Here, we review recent progress of carbon-based microfiber electrodes in terms of material composition and fabrication technology. The remaining challenges and future directions for development of these arrays will also be discussed. Overall, these microfiber electrodes are expected to improve the longevity and reliability of neural interfacing devices.
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Affiliation(s)
- Maryam Hejazi
- School of Physics, The University of Melbourne, Parkville, VIC, Australia
| | - Wei Tong
- School of Physics, The University of Melbourne, Parkville, VIC, Australia
- National Vision Research Institute, The Australian College of Optometry, Carlton, VIC, Australia
| | - Michael R. Ibbotson
- National Vision Research Institute, The Australian College of Optometry, Carlton, VIC, Australia
- Department of Optometry and Vision Sciences, The University of Melbourne, Parkville, VIC, Australia
| | - Steven Prawer
- School of Physics, The University of Melbourne, Parkville, VIC, Australia
| | - David J. Garrett
- School of Physics, The University of Melbourne, Parkville, VIC, Australia
- School of Engineering, RMIT University, Melbourne, VIC, Australia
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Santi S, Corridori I, Pugno NM, Motta A, Migliaresi C. Injectable Scaffold-Systems for the Regeneration of Spinal Cord: Advances of the Past Decade. ACS Biomater Sci Eng 2021; 7:983-999. [PMID: 33523634 DOI: 10.1021/acsbiomaterials.0c01779] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Nowadays, whenever is possible and as an alternative to open spine surgery, minimally invasive procedures are preferred to treat spinal cord injuries (SCI), with percutaneous injections or small incisions, that are faster, less traumatic, and require less recovery time. Injectable repair systems are based on materials that can be injected in the lesion site, can eventually be loaded with drugs or even cells, and act as scaffolds for the lesion repair. The review analyzes papers written from 2010 onward on injectable materials/systems used/proposed for the regenerative and combinatorial therapies of SCI and discusses the in vivo models that have been used to validate them.
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Affiliation(s)
- Sofia Santi
- BIOTech Research Center and European Institute of Excellence on Tissue Engineering and Regenerative Medicine, University of Trento, Via delle Regole 101, 38123 Trento, Italy.,Department of Industrial Engineering, University of Trento, Via Sommarive 9, 38123 Trento, Italy
| | - Ilaria Corridori
- Laboratory of Bio-inspired, Bionic, Nano, Meta Materials & Mechanics, Department of Civil, Environmental and Mechanical Engineering, University of Trento, Via Mesiano 77, 38123 Trento, Italy
| | - Nicola M Pugno
- Laboratory of Bio-inspired, Bionic, Nano, Meta Materials & Mechanics, Department of Civil, Environmental and Mechanical Engineering, University of Trento, Via Mesiano 77, 38123 Trento, Italy.,School of Engineering and Material Science, Queen Mary University of London, Mile End Road, E1 4NS London, United Kingdom
| | - Antonella Motta
- BIOTech Research Center and European Institute of Excellence on Tissue Engineering and Regenerative Medicine, University of Trento, Via delle Regole 101, 38123 Trento, Italy.,Department of Industrial Engineering, University of Trento, Via Sommarive 9, 38123 Trento, Italy
| | - Claudio Migliaresi
- BIOTech Research Center and European Institute of Excellence on Tissue Engineering and Regenerative Medicine, University of Trento, Via delle Regole 101, 38123 Trento, Italy.,Department of Industrial Engineering, University of Trento, Via Sommarive 9, 38123 Trento, Italy
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El Waly B, Escarrat V, Perez-Sanchez J, Kaur J, Pelletier F, Collazos-Castro JE, Debarbieux F. Intravital Assessment of Cells Responses to Conducting Polymer-Coated Carbon Microfibres for Bridging Spinal Cord Injury. Cells 2021; 10:cells10010073. [PMID: 33466339 PMCID: PMC7824803 DOI: 10.3390/cells10010073] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2020] [Revised: 12/27/2020] [Accepted: 12/29/2020] [Indexed: 12/18/2022] Open
Abstract
The extension of the lesion following spinal cord injury (SCI) poses a major challenge for regenerating axons, which must grow across several centimetres of damaged tissue in the absence of ordered guidance cues. Biofunctionalized electroconducting microfibres (MFs) that provide biochemical signals, as well as electrical and mechanical cues, offer a promising therapeutic approach to help axons overcome this blind journey. We used poly(3,4-ethylenedioxythiophene)-coated carbon MFs functionalized with cell adhesion molecules and growth factors to bridge the spinal cord after a partial unilateral dorsal quadrant lesion (PUDQL) in mice and followed cellular responses by intravital two-photon (2P) imaging through a spinal glass window. Thy1-CFP//LysM-EGFP//CD11c-EYFP triple transgenic reporter animals allowed real time simultaneous monitoring of axons, myeloid cells and microglial cells in the vicinity of the implanted MFs. MF biocompatibility was confirmed by the absence of inflammatory storm after implantation. We found that the sprouting of sensory axons was significantly accelerated by the implantation of functionalized MFs after PUDQL. Their implantation produced better axon alignment compared to random and misrouted axon regeneration that occurred in the absence of MF, with a most striking effect occurring two months after injury. Importantly, we observed differences in the intensity and composition of the innate immune response in comparison to PUDQL-only animals. A significant decrease of immune cell density was found in MF-implanted mice one month after lesion along with a higher ratio of monocyte-derived dendritic cells whose differentiation was accelerated. Therefore, functionalized carbon MFs promote the beneficial immune responses required for neural tissue repair, providing an encouraging strategy for SCI management.
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Affiliation(s)
- Bilal El Waly
- Institut des Neurosciences de la Timone (UMR7289), Aix-Marseille Université and Centre National de la Recherche Scientifique, 13005 Marseille, France; (B.E.W.); (V.E.); (J.P.-S.); (J.K.); (F.P.)
- Centre Européen de Recherche en Imagerie Médicale, Aix-Marseille Université, 13005 Marseille, France
| | - Vincent Escarrat
- Institut des Neurosciences de la Timone (UMR7289), Aix-Marseille Université and Centre National de la Recherche Scientifique, 13005 Marseille, France; (B.E.W.); (V.E.); (J.P.-S.); (J.K.); (F.P.)
- Centre Européen de Recherche en Imagerie Médicale, Aix-Marseille Université, 13005 Marseille, France
| | - Jimena Perez-Sanchez
- Institut des Neurosciences de la Timone (UMR7289), Aix-Marseille Université and Centre National de la Recherche Scientifique, 13005 Marseille, France; (B.E.W.); (V.E.); (J.P.-S.); (J.K.); (F.P.)
- Centre Européen de Recherche en Imagerie Médicale, Aix-Marseille Université, 13005 Marseille, France
| | - Jaspreet Kaur
- Institut des Neurosciences de la Timone (UMR7289), Aix-Marseille Université and Centre National de la Recherche Scientifique, 13005 Marseille, France; (B.E.W.); (V.E.); (J.P.-S.); (J.K.); (F.P.)
- Centre Européen de Recherche en Imagerie Médicale, Aix-Marseille Université, 13005 Marseille, France
- Department of Neuroscience, University of Copenhagen, 2200 Copenhagen N, Denmark
| | - Florence Pelletier
- Institut des Neurosciences de la Timone (UMR7289), Aix-Marseille Université and Centre National de la Recherche Scientifique, 13005 Marseille, France; (B.E.W.); (V.E.); (J.P.-S.); (J.K.); (F.P.)
- Centre Européen de Recherche en Imagerie Médicale, Aix-Marseille Université, 13005 Marseille, France
| | - Jorge Eduardo Collazos-Castro
- Neural Repair and Biomaterials Laboratory, Hospital Nacional de Parapléjicos (SESCAM), 45071 Toledo, Spain
- Correspondence: (J.C.-C.); (F.D.); Tel.:+34-925-247758 (J.C.-C.); +33-491-324186 (F.D.)
| | - Franck Debarbieux
- Institut des Neurosciences de la Timone (UMR7289), Aix-Marseille Université and Centre National de la Recherche Scientifique, 13005 Marseille, France; (B.E.W.); (V.E.); (J.P.-S.); (J.K.); (F.P.)
- Centre Européen de Recherche en Imagerie Médicale, Aix-Marseille Université, 13005 Marseille, France
- Institut Universitaire de France, 75005 Paris, France
- Correspondence: (J.C.-C.); (F.D.); Tel.:+34-925-247758 (J.C.-C.); +33-491-324186 (F.D.)
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Dalrymple AN, Huynh M, Nayagam BA, Lee CD, Weiland GR, Petrossians A, J J, Iii W, Fallon JB, Shepherd RK. Electrochemical and biological characterization of thin-film platinum-iridium alloy electrode coatings: a chronic in vivo study. J Neural Eng 2020; 17:036012. [PMID: 32408281 DOI: 10.1088/1741-2552/ab933d] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
OBJECTIVE To evaluate the electrochemical properties, biological response, and surface characterization of an electrodeposited Platinum-Iridium (Pt-Ir) electrode coating on cochlear implants subjected to chronic stimulation in vivo. APPROACH Electrochemical impedance spectroscopy (EIS), charge storage capacity (CSC), charge injection limit (CIL), and voltage transient (VT) impedance were measured bench-top before and after implant and in vivo. Coated Pt-Ir and uncoated Pt electrode arrays were implanted into cochlea of normal hearing rats and stimulated for ∼4 h d, 5 d week-1 for 5 weeks at levels within the normal clinical range. Neural function was monitored using electrically-evoked auditory brainstem responses. After explant, the electrode surfaces were assessed, and cochleae examined histologically. MAIN RESULTS When measured on bench-top before and after stimulation, Pt-Ir coated electrodes had significantly lower VT impedance (p < 0.001) and significantly higher CSC (p < 0.001) and CIL (p < 0.001) compared to uncoated Pt electrodes. In vivo, the CSC and CIL of Pt-Ir were significantly higher than Pt throughout the implantation period (p= 0.047 and p< 0.001, respectively); however, the VT impedance (p= 0.3) was not. There was no difference in foreign body response between material cohorts, although cochleae implanted with coated electrodes contained small deposits of Pt-Ir. There was no evidence of increased neural loss or loss of neural function in either group. Surface examination revealed no Pt corrosion on any electrodes. SIGNIFICANCE Electrodeposited Pt-Ir electrodes demonstrated significant improvements in electrochemical performance on the bench-top and in vivo compared to uncoated Pt. Neural function and tissue response to Pt-Ir electrodes were not different from uncoated Pt, despite small deposits of Pt-Ir in the tissue capsule. Electrodeposited Pt-Ir coatings offer promise as an improved electrode coating for active neural prostheses.
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Dalrymple AN, Robles UA, Huynh M, Nayagam BA, Green RA, Poole-Warren LA, Fallon JB, Shepherd RK. Electrochemical and biological performance of chronically stimulated conductive hydrogel electrodes. J Neural Eng 2020; 17:026018. [DOI: 10.1088/1741-2552/ab7cfc] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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Dalrymple AN, Huynh M, Robles UA, Marroquin JB, Lee CD, Petrossians A, Whalen JJ, Li D, Parkington HC, Forsythe JS, Green RA, Poole-Warren LA, Shepherd RK, Fallon JB. Electrochemical and mechanical performance of reduced graphene oxide, conductive hydrogel, and electrodeposited Pt-Ir coated electrodes: an active in vitro study. J Neural Eng 2019; 17:016015. [PMID: 31652427 DOI: 10.1088/1741-2552/ab5163] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
OBJECTIVE To systematically compare the in vitro electrochemical and mechanical properties of several electrode coatings that have been reported to increase the efficacy of medical bionics devices by increasing the amount of charge that can be delivered safely to the target neural tissue. APPROACH Smooth platinum (Pt) ring and disc electrodes were coated with reduced graphene oxide, conductive hydrogel, or electrodeposited Pt-Ir. Electrodes with coatings were compared with uncoated smooth Pt electrodes before and after an in vitro accelerated aging protocol. The various coatings were compared mechanically using the adhesion-by-tape test. Electrodes were stimulated in saline for 24 hours/day 7 days/week for 21 d at 85 °C (1.6-year equivalence) at a constant charge density of 200 µC/cm2/phase. Electrodes were graded on surface corrosion and trace analysis of Pt in the electrolyte after aging. Electrochemical measurements performed before, during, and after aging included electrochemical impedance spectroscopy, cyclic voltammetry, and charge injection limit and impedance from voltage transient recordings. MAIN RESULTS All three coatings adhered well to smooth Pt and exhibited electrochemical advantage over smooth Pt electrodes prior to aging. After aging, graphene coated electrodes displayed a stimulation-induced increase in impedance and reduction in the charge injection limit (p < 0.001), alongside extensive corrosion and release of Pt into the electrolyte. In contrast, both conductive hydrogel and Pt-Ir coated electrodes had smaller impedances and larger charge injection limits than smooth Pt electrodes (p < 0.001) following aging regardless of the stimulus level and with little evidence of corrosion or Pt dissolution. SIGNIFICANCE This study rigorously tested the mechanical and electrochemical performance of electrode coatings in vitro and provided suitable candidates for future in vivo testing.
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