1
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Wu B, Castagnola E, McClung CA, Cui XT. PEDOT/CNT Flexible MEAs Reveal New Insights into the Clock Gene's Role in Dopamine Dynamics. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024; 11:e2308212. [PMID: 38430532 PMCID: PMC11251561 DOI: 10.1002/advs.202308212] [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: 10/31/2023] [Revised: 01/26/2024] [Indexed: 03/04/2024]
Abstract
Substantial evidence has shown that the Circadian Locomotor Output Cycles Kaput (Clock) gene is a core transcription factor of circadian rhythms that regulates dopamine (DA) synthesis. To shed light on the mechanism of this interaction, flexible multielectrode arrays (MEAs) are developed that can measure both DA concentrations and electrophysiology chronically. The dual functionality is enabled by conducting polymer PEDOT doped with acid-functionalized carbon nanotubes (CNT). The PEDOT/CNT microelectrode coating maintained stable electrochemical impedance and DA detection by square wave voltammetry for 4 weeks in vitro. When implanted in wild-type (WT) and Clock mutation (MU) mice, MEAs measured tonic DA concentration and extracellular neural activity with high spatial and temporal resolution for 4 weeks. A diurnal change of DA concentration in WT is observed, but not in MU, and a higher basal DA concentration and stronger cocaine-induced DA increase in MU. Meanwhile, striatal neuronal firing rate is found to be positively correlated with DA concentration in both animal groups. These findings offer new insights into DA dynamics in the context of circadian rhythm regulation, and the chronically reliable performance and dual measurement capability of this technology hold great potential for a broad range of neuroscience research.
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Affiliation(s)
- Bingchen Wu
- Department of BioengineeringUniversity of PittsburghPittsburghPA15213USA
- Center for the Neural Basis of CognitionPittsburghPA15213USA
| | - Elisa Castagnola
- Department of BioengineeringUniversity of PittsburghPittsburghPA15213USA
- Department of Biomedical EngineeringLouisiana Tech UniversityRustonLA71272USA
| | | | - Xinyan Tracy Cui
- Department of BioengineeringUniversity of PittsburghPittsburghPA15213USA
- Center for the Neural Basis of CognitionPittsburghPA15213USA
- McGowan Institute for Regenerative MedicinePittsburghPA15219USA
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2
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Li Q, Yan F, Texter J. Polymerized and Colloidal Ionic Liquids─Syntheses and Applications. Chem Rev 2024; 124:3813-3931. [PMID: 38512224 DOI: 10.1021/acs.chemrev.3c00429] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/22/2024]
Abstract
The breadth and importance of polymerized ionic liquids (PILs) are steadily expanding, and this review updates advances and trends in syntheses, properties, and applications over the past five to six years. We begin with an historical overview of the genesis and growth of the PIL field as a subset of materials science. The genesis of ionic liquids (ILs) over nano to meso length-scales exhibiting 0D, 1D, 2D, and 3D topologies defines colloidal ionic liquids, CILs, which compose a subclass of PILs and provide a synthetic bridge between IL monomers (ILMs) and micro to macro-scale PIL materials. The second focus of this review addresses design and syntheses of ILMs and their polymerization reactions to yield PILs and PIL-based materials. A burgeoning diversity of ILMs reflects increasing use of nonimidazolium nuclei and an expanding use of step-growth chemistries in synthesizing PIL materials. Radical chain polymerization remains a primary method of making PILs and reflects an increasing use of controlled polymerization methods. Step-growth chemistries used in creating some CILs utilize extensive cross-linking. This cross-linking is enabled by incorporating reactive functionalities in CILs and PILs, and some of these CILs and PILs may be viewed as exotic cross-linking agents. The third part of this update focuses upon some advances in key properties, including molecular weight, thermal properties, rheology, ion transport, self-healing, and stimuli-responsiveness. Glass transitions, critical solution temperatures, and liquidity are key thermal properties that tie to PIL rheology and viscoelasticity. These properties in turn modulate mechanical properties and ion transport, which are foundational in increasing applications of PILs. Cross-linking in gelation and ionogels and reversible step-growth chemistries are essential for self-healing PILs. Stimuli-responsiveness distinguishes PILs from many other classes of polymers, and it emphasizes the importance of segmentally controlling and tuning solvation in CILs and PILs. The fourth part of this review addresses development of applications, and the diverse scope of such applications supports the increasing importance of PILs in materials science. Adhesion applications are supported by ionogel properties, especially cross-linking and solvation tunable interactions with adjacent phases. Antimicrobial and antifouling applications are consequences of the cationic nature of PILs. Similarly, emulsion and dispersion applications rely on tunable solvation of functional groups and on how such groups interact with continuous phases and substrates. Catalysis is another significant application, and this is an historical tie between ILs and PILs. This component also provides a connection to diverse and porous carbon phases templated by PILs that are catalysts or serve as supports for catalysts. Devices, including sensors and actuators, also rely on solvation tuning and stimuli-responsiveness that include photo and electrochemical stimuli. We conclude our view of applications with 3D printing. The largest components of these applications are energy related and include developments for supercapacitors, batteries, fuel cells, and solar cells. We conclude with our vision of how PIL development will evolve over the next decade.
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Affiliation(s)
- Qi Li
- Department of Materials Science, School of Chemistry and Chemical Engineering, Nantong University, Nantong 226019, Jiangsu, PR China
| | - Feng Yan
- Department of Polymer Science and Engineering, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, Jiangsu, PR China
| | - John Texter
- Strider Research Corporation, Rochester, New York 14610-2246, United States
- School of Engineering, Eastern Michigan University, Ypsilanti, Michigan 48197, United States
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3
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Sha B, Du Z. Neural repair and regeneration interfaces: a comprehensive review. Biomed Mater 2024; 19:022002. [PMID: 38232383 DOI: 10.1088/1748-605x/ad1f78] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Accepted: 01/17/2024] [Indexed: 01/19/2024]
Abstract
Neural interfaces play a pivotal role in neuromodulation, as they enable precise intervention into aberrant neural activity and facilitate recovery from neural injuries and resultant functional impairments by modulating local immune responses and neural circuits. This review outlines the development and applications of these interfaces and highlights the advantages of employing neural interfaces for neural stimulation and repair, including accurate targeting of specific neural populations, real-time monitoring and control of neural activity, reduced invasiveness, and personalized treatment strategies. Ongoing research aims to enhance the biocompatibility, stability, and functionality of these interfaces, ultimately augmenting their therapeutic potential for various neurological disorders. The review focuses on electrophysiological and optophysiology neural interfaces, discussing functionalization and power supply approaches. By summarizing the techniques, materials, and methods employed in this field, this review aims to provide a comprehensive understanding of the potential applications and future directions for neural repair and regeneration devices.
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Affiliation(s)
- Baoning Sha
- Brain Cognition and Brain Disease Institute, CAS Key Laboratory of Brain Connectome and Manipulation, Guangdong Provincial Key Laboratory of Brain Connectome and Behavior, Shenzhen institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, People's Republic of China
- Shenzhen-Hong Kong Institute of Brain Science, Shenzhen Fundamental Research Institutions, Shenzhen, People's Republic of China
- Department of Biomedical Engineering, Columbia University, New York, NY, United States of America
| | - Zhanhong Du
- Brain Cognition and Brain Disease Institute, CAS Key Laboratory of Brain Connectome and Manipulation, Guangdong Provincial Key Laboratory of Brain Connectome and Behavior, Shenzhen institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, People's Republic of China
- Shenzhen-Hong Kong Institute of Brain Science, Shenzhen Fundamental Research Institutions, Shenzhen, People's Republic of China
- University of Chinese Academy of Sciences, Beijing, People's Republic of China
- Faculty of Life and Health Sciences, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, People's Republic of China
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4
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Qian S, Lin HA, Pan Q, Zhang S, Zhang Y, Geng Z, Wu Q, He Y, Zhu B. Chemically revised conducting polymers with inflammation resistance for intimate bioelectronic electrocoupling. Bioact Mater 2023; 26:24-51. [PMID: 36875055 PMCID: PMC9975642 DOI: 10.1016/j.bioactmat.2023.02.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Revised: 01/26/2023] [Accepted: 02/10/2023] [Indexed: 02/23/2023] Open
Abstract
Conducting polymers offer attractive mixed ionic-electronic conductivity, tunable interfacial barrier with metal, tissue matchable softness, and versatile chemical functionalization, making them robust to bridge the gap between brain tissue and electronic circuits. This review focuses on chemically revised conducting polymers, combined with their superior and controllable electrochemical performance, to fabricate long-term bioelectronic implants, addressing chronic immune responses, weak neuron attraction, and long-term electrocommunication instability challenges. Moreover, the promising progress of zwitterionic conducting polymers in bioelectronic implants (≥4 weeks stable implantation) is highlighted, followed by a comment on their current evolution toward selective neural coupling and reimplantable function. Finally, a critical forward look at the future of zwitterionic conducting polymers for in vivo bioelectronic devices is provided.
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Affiliation(s)
- Sihao Qian
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University, Shanghai, 201620, China.,School of Materials Science and Engineering & Shanghai Engineering Research Center of Organ Repair, Shanghai University, Shanghai, 200444, China
| | - Hsing-An Lin
- School of Materials Science and Engineering & Shanghai Engineering Research Center of Organ Repair, Shanghai University, Shanghai, 200444, China
| | - Qichao Pan
- School of Materials Science and Engineering & Shanghai Engineering Research Center of Organ Repair, Shanghai University, Shanghai, 200444, China
| | - Shuhua Zhang
- School of Materials Science and Engineering & Shanghai Engineering Research Center of Organ Repair, Shanghai University, Shanghai, 200444, China
| | - Yunhua Zhang
- School of Materials Science and Engineering & Shanghai Engineering Research Center of Organ Repair, Shanghai University, Shanghai, 200444, China
| | - Zhi Geng
- School of Materials Science and Engineering & Shanghai Engineering Research Center of Organ Repair, Shanghai University, Shanghai, 200444, China
| | - Qing Wu
- School of Materials Science and Engineering & Shanghai Engineering Research Center of Organ Repair, Shanghai University, Shanghai, 200444, China
| | - Yong He
- Innovation Center for Textile Science and Technology, Donghua University, Shanghai, 201620, China
| | - Bo Zhu
- School of Materials Science and Engineering & Shanghai Engineering Research Center of Organ Repair, Shanghai University, Shanghai, 200444, China
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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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Wu B, Castagnola E, Cui XT. Zwitterionic Polymer Coated and Aptamer Functionalized Flexible Micro-Electrode Arrays for In Vivo Cocaine Sensing and Electrophysiology. MICROMACHINES 2023; 14:323. [PMID: 36838023 PMCID: PMC9967584 DOI: 10.3390/mi14020323] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/17/2022] [Revised: 01/19/2023] [Accepted: 01/25/2023] [Indexed: 06/18/2023]
Abstract
The number of people aged 12 years and older using illicit drugs reached 59.3 million in 2020, among which 5.2 million are cocaine users based on the national data. In order to fully understand cocaine addiction and develop effective therapies, a tool is needed to reliably measure real-time cocaine concentration and neural activity in different regions of the brain with high spatial and temporal resolution. Integrated biochemical sensing devices based upon flexible microelectrode arrays (MEA) have emerged as a powerful tool for such purposes; however, MEAs suffer from undesired biofouling and inflammatory reactions, while those with immobilized biologic sensing elements experience additional failures due to biomolecule degradation. Aptasensors are powerful tools for building highly selective sensors for analytes that have been difficult to detect. In this work, DNA aptamer-based electrochemical cocaine sensors were integrated on flexible MEAs and protected with an antifouling zwitterionic poly (sulfobetaine methacrylate) (PSB) coating, in order to prevent sensors from biofouling and degradation by the host tissue. In vitro experiments showed that without the PSB coating, both adsorption of plasma protein albumin and exposure to DNase-1 enzyme have detrimental effects on sensor performance, decreasing signal amplitude and the sensitivity of the sensors. Albumin adsorption caused a 44.4% sensitivity loss, and DNase-1 exposure for 24 hr resulted in a 57.2% sensitivity reduction. The PSB coating successfully protected sensors from albumin fouling and DNase-1 enzyme digestion. In vivo tests showed that the PSB coated MEA aptasensors can detect repeated cocaine infusions in the brain for 3 hrs after implantation without sensitivity degradation. Additionally, the same MEAs can record electrophysiological signals at different tissue depths simultaneously. This novel flexible MEA with integrated cocaine sensors can serve as a valuable tool for understanding the mechanisms of cocaine addiction, while the PSB coating technology can be generalized to improve all implantable devices suffering from biofouling and inflammatory host responses.
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Affiliation(s)
- Bingchen Wu
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA 15213, USA
- Center for the Neural Basis of Cognition, Pittsburgh, PA 15213, USA
| | - Elisa Castagnola
- Department of Biomedical Engineering, Louisiana Tech University, Ruston, LA 71272, USA
| | - Xinyan Tracy Cui
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA 15213, USA
- Center for the Neural Basis of Cognition, Pittsburgh, PA 15213, USA
- McGowan Institute for Regenerative Medicine, Pittsburgh, PA 15219, USA
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7
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Wang Y, Yang X, Zhang X, Wang Y, Pei W. Implantable intracortical microelectrodes: reviewing the present with a focus on the future. MICROSYSTEMS & NANOENGINEERING 2023; 9:7. [PMID: 36620394 PMCID: PMC9814492 DOI: 10.1038/s41378-022-00451-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/07/2022] [Revised: 08/08/2022] [Accepted: 08/22/2022] [Indexed: 06/17/2023]
Abstract
Implantable intracortical microelectrodes can record a neuron's rapidly changing action potentials (spikes). In vivo neural activity recording methods often have either high temporal or spatial resolution, but not both. There is an increasing need to record more neurons over a longer duration in vivo. However, there remain many challenges to overcome before achieving long-term, stable, high-quality recordings and realizing comprehensive, accurate brain activity analysis. Based on the vision of an idealized implantable microelectrode device, the performance requirements for microelectrodes are divided into four aspects, including recording quality, recording stability, recording throughput, and multifunctionality, which are presented in order of importance. The challenges and current possible solutions for implantable microelectrodes are given from the perspective of each aspect. The current developments in microelectrode technology are analyzed and summarized.
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Affiliation(s)
- Yang Wang
- State Key Laboratory of Integrated Optoelectronics, Institute of Semiconductors, Chinese Academy of Sciences, 100083 Beijing, China
- University of Chinese Academy of Sciences, 100049 Beijing, China
| | - Xinze Yang
- State Key Laboratory of Integrated Optoelectronics, Institute of Semiconductors, Chinese Academy of Sciences, 100083 Beijing, China
- University of Chinese Academy of Sciences, 100049 Beijing, China
| | - Xiwen Zhang
- State Key Laboratory of Integrated Optoelectronics, Institute of Semiconductors, Chinese Academy of Sciences, 100083 Beijing, China
- University of Chinese Academy of Sciences, 100049 Beijing, China
| | - Yijun Wang
- State Key Laboratory of Integrated Optoelectronics, Institute of Semiconductors, Chinese Academy of Sciences, 100083 Beijing, China
- University of Chinese Academy of Sciences, 100049 Beijing, China
- Chinese Institute for Brain Research, 102206 Beijing, China
| | - Weihua Pei
- State Key Laboratory of Integrated Optoelectronics, Institute of Semiconductors, Chinese Academy of Sciences, 100083 Beijing, China
- University of Chinese Academy of Sciences, 100049 Beijing, China
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8
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Dong M, Coleman HA, Tonta MA, Xiong Z, Li D, Thomas S, Liu M, Fallon JB, Parkington HC, Forsythe JS. Rapid electrophoretic deposition of biocompatible graphene coatings for high-performance recording neural electrodes. NANOSCALE 2022; 14:15845-15858. [PMID: 36259692 DOI: 10.1039/d2nr04421h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
The electrical and biological interfacial properties of invasive electrodes have a significant impact on the performance and longevity of neural recordings in the brain. In this study, we demonstrated rapid electrophoretic deposition and electrochemical reduction of graphene oxide (GO) on metal-based neural electrodes. Scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and other characterizations confirmed the existence of a uniform and effectively reduced graphene oxide coating. Electrochemically reduced graphene oxide (ErGO) coated Pt/Ir neural electrodes exhibited 15.2-fold increase in charge storage capacity (CSC) and 90% decrease in impedance with only 3.8% increase in electrode diameter. Patch clamp electrophysiology and calcium imaging of primary rat hippocampus neurons cultured on ErGO demonstrated that there was no adverse impact on the functional development of neurons. Immunostaining showed a balanced growth of excitatory and inhibitory neurons, and astrocytes. Acute recordings from the auditory cortex and chronic recordings (19 days) from the somatosensory cortex found ErGO coating improved the performance of neural electrodes in signal-to-noise ratio (SNR) and amplitude of signals. The proposed approach not only provides an in-depth evaluation of the effect of ErGO coating on neural electrodes but also widens the coating methods of commercial neural electrodes.
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Affiliation(s)
- Miheng Dong
- Department of Materials Science and Engineering, Monash Institute of Medical Engineering, Monash University, Clayton, VIC 3800, Australia.
- Monash Suzhou Research Institute, Monash University, Suzhou SIP 250000, China
| | - Harold A Coleman
- Department of Physiology, Biomedicine Discovery Institute, Monash University, Clayton, VIC 3800, Australia
| | - Mary A Tonta
- Department of Physiology, Biomedicine Discovery Institute, Monash University, Clayton, VIC 3800, Australia
| | - Zhiyuan Xiong
- Department of Chemical Engineering, University of Melbourne, Parkville, Victoria, Australia
| | - Dan Li
- Department of Chemical Engineering, University of Melbourne, Parkville, Victoria, Australia
| | - Sebastian Thomas
- Department of Materials Science and Engineering, Monash Institute of Medical Engineering, Monash University, Clayton, VIC 3800, Australia.
| | - Minsu Liu
- Department of Materials Science and Engineering, Monash Institute of Medical Engineering, Monash University, Clayton, VIC 3800, Australia.
- Monash Suzhou Research Institute, Monash University, Suzhou SIP 250000, China
- Foshan (Southern China) Institute for New Materials, Foshan 528200, China
| | - James B Fallon
- The Bionics Institute, East Melbourne, Victoria 3002, Australia
- Medical Bionics Department, University of Melbourne, Parkville, Victoria 3010, Australia
| | - Helena C Parkington
- Department of Physiology, Biomedicine Discovery Institute, Monash University, Clayton, VIC 3800, Australia
| | - John S Forsythe
- Department of Materials Science and Engineering, Monash Institute of Medical Engineering, Monash University, Clayton, VIC 3800, Australia.
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9
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Amini S, Seche W, May N, Choi H, Tavousi P, Shahbazmohamadi S. Femtosecond laser hierarchical surface restructuring for next generation neural interfacing electrodes and microelectrode arrays. Sci Rep 2022; 12:13966. [PMID: 35978090 PMCID: PMC9385846 DOI: 10.1038/s41598-022-18161-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Accepted: 08/05/2022] [Indexed: 11/09/2022] Open
Abstract
Long-term implantable neural interfacing devices are able to diagnose, monitor, and treat many cardiac, neurological, retinal and hearing disorders through nerve stimulation, as well as sensing and recording electrical signals to and from neural tissue. To improve specificity, functionality, and performance of these devices, the electrodes and microelectrode arrays-that are the basis of most emerging devices-must be further miniaturized and must possess exceptional electrochemical performance and charge exchange characteristics with neural tissue. In this report, we show for the first time that the electrochemical performance of femtosecond-laser hierarchically-restructured electrodes can be tuned to yield unprecedented performance values that significantly exceed those reported in the literature, e.g. charge storage capacity and specific capacitance were shown to have improved by two orders of magnitude and over 700-fold, respectively, compared to un-restructured electrodes. Additionally, correlation amongst laser parameters, electrochemical performance and surface parameters of the electrodes was established, and while performance metrics exhibit a relatively consistent increasing behavior with laser parameters, surface parameters tend to follow a less predictable trend negating a direct relationship between these surface parameters and performance. To answer the question of what drives such performance and tunability, and whether the widely adopted reasoning of increased surface area and roughening of the electrodes are the key contributors to the observed increase in performance, cross-sectional analysis of the electrodes using focused ion beam shows, for the first time, the existence of subsurface features that may have contributed to the observed electrochemical performance enhancements. This report is the first time that such performance enhancement and tunability are reported for femtosecond-laser hierarchically-restructured electrodes for neural interfacing applications.
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Affiliation(s)
- Shahram Amini
- Research and Development, Pulse Technologies Inc., Quakertown, PA, 18951, USA. .,Biomedical Engineering Department, University of Connecticut, Storrs, CT, 06269, USA.
| | - Wesley Seche
- Research and Development, Pulse Technologies Inc., Quakertown, PA, 18951, USA
| | - Nicholas May
- Biomedical Engineering Department, University of Connecticut, Storrs, CT, 06269, USA
| | - Hongbin Choi
- Biomedical Engineering Department, University of Connecticut, Storrs, CT, 06269, USA
| | - Pouya Tavousi
- UConn Tech Park, University of Connecticut, Storrs, CT, 06269, USA
| | - Sina Shahbazmohamadi
- Biomedical Engineering Department, University of Connecticut, Storrs, CT, 06269, USA
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10
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Xu S, Deng Y, Luo J, Liu Y, He E, Yang Y, Zhang K, Sha L, Dai Y, Ming T, Song Y, Jing L, Zhuang C, Xu Q, Cai X. A Neural Sensor with a Nanocomposite Interface for the Study of Spike Characteristics of Hippocampal Neurons under Learning Training. BIOSENSORS 2022; 12:bios12070546. [PMID: 35884349 PMCID: PMC9312960 DOI: 10.3390/bios12070546] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Revised: 07/19/2022] [Accepted: 07/19/2022] [Indexed: 11/16/2022]
Abstract
Both the cellular- and population-level properties of involved neurons are essential for unveiling the learning and memory functions of the brain. To give equal attention to these two aspects, neural sensors based on microelectrode arrays (MEAs) have been in the limelight due to their noninvasive detection and regulation capabilities. Here, we fabricated a neural sensor using carboxylated graphene/3,4-ethylenedioxythiophene:polystyrenesulfonate (cGO/PEDOT:PSS), which is effective in sensing and monitoring neuronal electrophysiological activity in vitro for a long time. The cGO/PEDOT:PSS-modified microelectrodes exhibited a lower electrochemical impedance (7.26 ± 0.29 kΩ), higher charge storage capacity (7.53 ± 0.34 mC/cm2), and improved charge injection (3.11 ± 0.25 mC/cm2). In addition, their performance was maintained after 2 to 4 weeks of long-term cell culture and 50,000 stimulation pulses. During neural network training, the sensors were able to induce learning function in hippocampal neurons through precise electrical stimulation and simultaneously detect changes in neural activity at multiple levels. At the cellular level, not only were three kinds of transient responses to electrical stimulation sensed, but electrical stimulation was also found to affect inhibitory neurons more than excitatory neurons. As for the population level, changes in connectivity and firing synchrony were identified. The cGO/PEDOT:PSS-based neural sensor offers an excellent tool in brain function development and neurological disease treatment.
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Affiliation(s)
- Shihong Xu
- State Key Laboratory of Transducer Technology, Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing 100190, China; (S.X.); (J.L.); (Y.L.); (E.H.); (Y.Y.); (K.Z.); (Y.D.); (T.M.); (Y.S.); (L.J.)
- School of Electronic, Electrical and Communication Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yu Deng
- State Key Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100005, China; (Y.D.); (L.S.); (Q.X.)
| | - Jinping Luo
- State Key Laboratory of Transducer Technology, Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing 100190, China; (S.X.); (J.L.); (Y.L.); (E.H.); (Y.Y.); (K.Z.); (Y.D.); (T.M.); (Y.S.); (L.J.)
- School of Electronic, Electrical and Communication Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yaoyao Liu
- State Key Laboratory of Transducer Technology, Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing 100190, China; (S.X.); (J.L.); (Y.L.); (E.H.); (Y.Y.); (K.Z.); (Y.D.); (T.M.); (Y.S.); (L.J.)
- School of Electronic, Electrical and Communication Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Enhui He
- State Key Laboratory of Transducer Technology, Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing 100190, China; (S.X.); (J.L.); (Y.L.); (E.H.); (Y.Y.); (K.Z.); (Y.D.); (T.M.); (Y.S.); (L.J.)
- School of Electronic, Electrical and Communication Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yan Yang
- State Key Laboratory of Transducer Technology, Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing 100190, China; (S.X.); (J.L.); (Y.L.); (E.H.); (Y.Y.); (K.Z.); (Y.D.); (T.M.); (Y.S.); (L.J.)
- School of Electronic, Electrical and Communication Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Kui Zhang
- State Key Laboratory of Transducer Technology, Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing 100190, China; (S.X.); (J.L.); (Y.L.); (E.H.); (Y.Y.); (K.Z.); (Y.D.); (T.M.); (Y.S.); (L.J.)
- School of Electronic, Electrical and Communication Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Longze Sha
- State Key Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100005, China; (Y.D.); (L.S.); (Q.X.)
| | - Yuchun Dai
- State Key Laboratory of Transducer Technology, Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing 100190, China; (S.X.); (J.L.); (Y.L.); (E.H.); (Y.Y.); (K.Z.); (Y.D.); (T.M.); (Y.S.); (L.J.)
- School of Electronic, Electrical and Communication Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Tao Ming
- State Key Laboratory of Transducer Technology, Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing 100190, China; (S.X.); (J.L.); (Y.L.); (E.H.); (Y.Y.); (K.Z.); (Y.D.); (T.M.); (Y.S.); (L.J.)
- School of Electronic, Electrical and Communication Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yilin Song
- State Key Laboratory of Transducer Technology, Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing 100190, China; (S.X.); (J.L.); (Y.L.); (E.H.); (Y.Y.); (K.Z.); (Y.D.); (T.M.); (Y.S.); (L.J.)
- School of Electronic, Electrical and Communication Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Luyi Jing
- State Key Laboratory of Transducer Technology, Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing 100190, China; (S.X.); (J.L.); (Y.L.); (E.H.); (Y.Y.); (K.Z.); (Y.D.); (T.M.); (Y.S.); (L.J.)
- School of Electronic, Electrical and Communication Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Chengyu Zhuang
- Department of Orthopaedics, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China;
| | - Qi Xu
- State Key Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100005, China; (Y.D.); (L.S.); (Q.X.)
| | - Xinxia Cai
- State Key Laboratory of Transducer Technology, Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing 100190, China; (S.X.); (J.L.); (Y.L.); (E.H.); (Y.Y.); (K.Z.); (Y.D.); (T.M.); (Y.S.); (L.J.)
- School of Electronic, Electrical and Communication Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
- Correspondence:
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11
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Sharafkhani N, Kouzani AZ, Adams SD, Long JM, Lissorgues G, Rousseau L, Orwa JO. Neural tissue-microelectrode interaction: Brain micromotion, electrical impedance, and flexible microelectrode insertion. J Neurosci Methods 2022; 365:109388. [PMID: 34678387 DOI: 10.1016/j.jneumeth.2021.109388] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 10/17/2021] [Accepted: 10/17/2021] [Indexed: 10/20/2022]
Abstract
Insertion of a microelectrode into the brain to record/stimulate neurons damages neural tissue and blood vessels and initiates the brain's wound healing response. Due to the large difference between the stiffness of neural tissue and microelectrode, brain micromotion also leads to neural tissue damage and associated local immune response. Over time, following implantation, the brain's response to the tissue damage can result in microelectrode failure. Reducing the microelectrode's cross-sectional dimensions to single-digit microns or using soft materials with elastic modulus close to that of the neural tissue are effective methods to alleviate the neural tissue damage and enhance microelectrode longevity. However, the increase in electrical impedance of the microelectrode caused by reducing the microelectrode contact site's dimensions can decrease the signal-to-noise ratio. Most importantly, the reduced dimensions also lead to a reduction in the critical buckling force, which increases the microelectrode's propensity to buckling during insertion. After discussing brain micromotion, the main source of neural tissue damage, surface modification of the microelectrode contact site is reviewed as a key method for addressing the increase in electrical impedance issue. The review then focuses on recent approaches to aiding insertion of flexible microelectrodes into the brain, including bending stiffness modification, effective length reduction, and application of a magnetic field to pull the electrode. An understanding of the advantages and drawbacks of the developed strategies offers a guide for dealing with the buckling phenomenon during implantation.
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Affiliation(s)
- Naser Sharafkhani
- School of Engineering, Deakin University, Geelong, VIC 3216, Australia.
| | - Abbas Z Kouzani
- School of Engineering, Deakin University, Geelong, VIC 3216, Australia
| | - Scott D Adams
- School of Engineering, Deakin University, Geelong, VIC 3216, Australia
| | - John M Long
- School of Engineering, Deakin University, Geelong, VIC 3216, Australia
| | | | | | - Julius O Orwa
- School of Engineering, Deakin University, Geelong, VIC 3216, Australia.
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12
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Pitsalidis C, Pappa AM, Boys AJ, Fu Y, Moysidou CM, van Niekerk D, Saez J, Savva A, Iandolo D, Owens RM. Organic Bioelectronics for In Vitro Systems. Chem Rev 2021; 122:4700-4790. [PMID: 34910876 DOI: 10.1021/acs.chemrev.1c00539] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Bioelectronics have made strides in improving clinical diagnostics and precision medicine. The potential of bioelectronics for bidirectional interfacing with biology through continuous, label-free monitoring on one side and precise control of biological activity on the other has extended their application scope to in vitro systems. The advent of microfluidics and the considerable advances in reliability and complexity of in vitro models promise to eventually significantly reduce or replace animal studies, currently the gold standard in drug discovery and toxicology testing. Bioelectronics are anticipated to play a major role in this transition offering a much needed technology to push forward the drug discovery paradigm. Organic electronic materials, notably conjugated polymers, having demonstrated technological maturity in fields such as solar cells and light emitting diodes given their outstanding characteristics and versatility in processing, are the obvious route forward for bioelectronics due to their biomimetic nature, among other merits. This review highlights the advances in conjugated polymers for interfacing with biological tissue in vitro, aiming ultimately to develop next generation in vitro systems. We showcase in vitro interfacing across multiple length scales, involving biological models of varying complexity, from cell components to complex 3D cell cultures. The state of the art, the possibilities, and the challenges of conjugated polymers toward clinical translation of in vitro systems are also discussed throughout.
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Affiliation(s)
- Charalampos Pitsalidis
- Department of Physics, Khalifa University of Science and Technology, P.O. Box 127788, Abu Dhabi 127788, UAE.,Department of Chemical Engineering and Biotechnology, University of Cambridge Philippa Fawcett Drive, Cambridge CB3 0AS, U.K
| | - Anna-Maria Pappa
- Department of Biomedical Engineering, Khalifa University of Science and Technology, P.O. Box 127788, Abu Dhabi 127788, UAE
| | - Alexander J Boys
- Department of Chemical Engineering and Biotechnology, University of Cambridge Philippa Fawcett Drive, Cambridge CB3 0AS, U.K
| | - Ying Fu
- Department of Chemical Engineering and Biotechnology, University of Cambridge Philippa Fawcett Drive, Cambridge CB3 0AS, U.K.,Department of Pure and Applied Chemistry, Technology and Innovation Centre, University of Strathclyde, Glasgow G1 1RD, U.K
| | - Chrysanthi-Maria Moysidou
- Department of Chemical Engineering and Biotechnology, University of Cambridge Philippa Fawcett Drive, Cambridge CB3 0AS, U.K
| | - Douglas van Niekerk
- Department of Chemical Engineering and Biotechnology, University of Cambridge Philippa Fawcett Drive, Cambridge CB3 0AS, U.K
| | - Janire Saez
- Department of Chemical Engineering and Biotechnology, University of Cambridge Philippa Fawcett Drive, Cambridge CB3 0AS, U.K.,Microfluidics Cluster UPV/EHU, BIOMICs Microfluidics Group, Lascaray Research Center, University of the Basque Country UPV/EHU, Avenida Miguel de Unamuno, 3, 01006 Vitoria-Gasteiz, Spain.,Ikerbasque, Basque Foundation for Science, E-48011 Bilbao, Spain
| | - Achilleas Savva
- Department of Chemical Engineering and Biotechnology, University of Cambridge Philippa Fawcett Drive, Cambridge CB3 0AS, U.K
| | - Donata Iandolo
- INSERM, U1059 Sainbiose, Université Jean Monnet, Mines Saint-Étienne, Université de Lyon, 42023 Saint-Étienne, France
| | - Róisín M Owens
- Department of Chemical Engineering and Biotechnology, University of Cambridge Philippa Fawcett Drive, Cambridge CB3 0AS, U.K
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13
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Zheng XS, Yang Q, Vazquez AL, Tracy Cui X. Imaging the Efficiency of Poly(3,4-ethylenedioxythiophene) Doped with Acid-Functionalized Carbon Nanotube and Iridium Oxide Electrode Coatings for Microstimulation. ADVANCED NANOBIOMED RESEARCH 2021; 1:2000092. [PMID: 34746928 PMCID: PMC8552016 DOI: 10.1002/anbr.202000092] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Revised: 03/18/2021] [Indexed: 12/02/2022] Open
Abstract
Electrical microstimulation has shown promise in restoring neural deficits in humans. Electrodes coated with materials like the conducting polymer poly(3,4-ethylenedioxythiophene) doped with acid-functionalized carbon nanotubes (PEDOT/CNTs, or PC) exhibit superior charge injection than traditional metals like platinum. However, the stimulation performance of PC remains to be fully characterized. Advanced imaging techniques and transgenic tools allow for real-time observations of neural activity in vivo. Herein, microelectrodes coated with PC and iridium oxide (IrOx) (a commonly used high-charge-injection material) are implanted in GCaMP6s mice and electrical stimulation is applied while imaging neuronal calcium responses. Results show that PC-coated electrodes stimulate more intense and broader GCaMP responses than IrOx. Two-photon microscopy reveals that PC-coated electrodes activate significantly more neuronal soma and neuropil than IrOx-coated electrodes in constant-voltage stimulation and significantly more neuronal soma in constant-current stimulation. Furthermore, with the same injected charge, both materials activate more spatially confined neural elements with shorter pulses than longer pulses, providing a means to tune stimulation selectivity. Finite element analyses reveal that the PC coating creates a denser and nonuniform electric field, increasing the likelihood of activating nearby neural elements. PC coating can significantly improve energy efficiency for electrical stimulation applications.
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Affiliation(s)
- Xin S. Zheng
- Department of BioengineeringUniversity of Pittsburgh3501 Fifth Ave.PittsburghPA15213USA
| | - Qianru Yang
- Department of BioengineeringUniversity of Pittsburgh3501 Fifth Ave.PittsburghPA15213USA
| | - Alberto L. Vazquez
- Departments of Radiology and BioengineeringUniversity of Pittsburgh3025 E. Carson St.PittsburghPA15203USA
| | - Xinyan Tracy Cui
- Department of BioengineeringUniversity of Pittsburgh3501 Fifth Ave.PittsburghPA15213USA
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14
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Skorupa M, Więcławska D, Czerwińska-Główka D, Skonieczna M, Krukiewicz K. Dopant-Dependent Electrical and Biological Functionality of PEDOT in Bioelectronics. Polymers (Basel) 2021; 13:1948. [PMID: 34208221 PMCID: PMC8230730 DOI: 10.3390/polym13121948] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Revised: 06/08/2021] [Accepted: 06/10/2021] [Indexed: 01/05/2023] Open
Abstract
The aspiration to interact living cells with electronics challenges researchers to develop materials working at the interface of these two distinct environments. A successful interfacing coating should exhibit both biocompatibility and desired functionality of a bio-integrated device. Taking into account biodiversity, the tissue interface should be fine-tuned to the specific requirements of the bioelectronic systems. In this study, we pointed to electrochemical doping of conducting polymers as a strategy enabling the efficient manufacturing of interfacing platforms, in which features could be easily adjusted. Consequently, we fabricated conducting films based on a poly(3,4-ethylenedioxythiophene) (PEDOT) matrix, with properties modulated through doping with selected ions: PSS- (poly(styrene sulfonate)), ClO4- (perchlorate), and PF6- (hexafluorophosphate). Striving to extend the knowledge on the relationships governing the dopant effect on PEDOT films, the samples were characterized in terms of their chemical, morphological, and electrochemical properties. To investigate the impact of the materials on attachment and growth of cells, rat neuroblastoma B35 cells were cultured on their surface and analyzed using scanning electron microscopy and biological assays. Eventually, it was shown that through the choice of a dopant and doping conditions, PEDOT-based materials can be efficiently tuned with diversified physicochemical properties. Therefore, our results proved electrochemical doping of PEDOT as a valuable strategy facilitating the development of promising tissue interfacing materials with characteristics tailored as required.
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Affiliation(s)
- Małgorzata Skorupa
- Department of Physical Chemistry and Technology of Polymers, Silesian University of Technology, 44-100 Gliwice, Poland; (M.S.); (D.W.); (D.C.-G.)
| | - Daria Więcławska
- Department of Physical Chemistry and Technology of Polymers, Silesian University of Technology, 44-100 Gliwice, Poland; (M.S.); (D.W.); (D.C.-G.)
| | - Dominika Czerwińska-Główka
- Department of Physical Chemistry and Technology of Polymers, Silesian University of Technology, 44-100 Gliwice, Poland; (M.S.); (D.W.); (D.C.-G.)
| | - Magdalena Skonieczna
- Biotechnology Centre, Silesian University of Technology, 44-100 Gliwice, Poland;
- Department of Systems Biology and Engineering, Faculty of Automatic Control, Electronics and Computer Science, Silesian University of Technology, 44-100 Gliwice, Poland
| | - Katarzyna Krukiewicz
- Department of Physical Chemistry and Technology of Polymers, Silesian University of Technology, 44-100 Gliwice, Poland; (M.S.); (D.W.); (D.C.-G.)
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15
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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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16
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Electrically conducting polymers for bio-interfacing electronics: From neural and cardiac interfaces to bone and artificial tissue biomaterials. Biosens Bioelectron 2020; 170:112620. [DOI: 10.1016/j.bios.2020.112620] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 08/31/2020] [Accepted: 09/14/2020] [Indexed: 02/08/2023]
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17
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Chakraborty B, Joshi-Imre A, Maeng J, Cogan SF. Sputtered ruthenium oxide coatings for neural stimulation and recording electrodes. J Biomed Mater Res B Appl Biomater 2020; 109:643-653. [PMID: 32945088 DOI: 10.1002/jbm.b.34728] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 08/17/2020] [Accepted: 09/02/2020] [Indexed: 12/28/2022]
Abstract
We have investigated the deposition and electrochemical properties of sputtered ruthenium oxide coatings for neural stimulation and recording electrodes. A combination of oxygen and water vapor was used as a reactive gas mixture during DC magnetron sputtering from a ruthenium metal target. The sputtering plasma was monitored by optical emission spectroscopy to determine the reactive species present and confirm the control of plasma chemistry by reactive gas flow rates into the deposition chamber. The effect of the O2 :H2 O gas ratio on the microstructure and electrochemical properties of the ruthenium oxide were studied in detail. We employed a combination of surface characterization techniques, including scanning electron microscopy, x-ray diffraction, and x-ray photoelectron spectroscopy, to understand the relationship between plasma chemistry and the microstructure of the films produced under different gas flow conditions. Electrochemical characterization included cyclic voltammetry, electrochemical impedance spectroscopy, and voltage transient measurements, performed on planar ruthenium oxide electrodes with a geometric surface area of 1960 μm2 . At an O2 :H2 O gas flow rate ratio of 1:3, a cathodal charge-storage capacity per unit film thickness of 228.7 mC cm-2 μm-1 (median, Q1 = 134.5, Q3 = 236.6, n = 15) and a charge-injection capacity (0.6 V anodal interpulse bias) of 7.4 mC cm-2 (median, Q1 = 6.9, Q3 = 8.3, n = 15) were obtained in phosphate buffered saline. The charge-injection capacity of ruthenium oxide sputtered with water vapor in the reactive plasma is comparable with sputtered iridium oxide (SIROF) and higher than reported values for porous TiN, a commonly employed high-surface area stimulation electrode coating.
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Affiliation(s)
- Bitan Chakraborty
- Department of Materials Science and Engineering, University of Texas at Dallas, Richardson, Texas, USA
| | - Alexandra Joshi-Imre
- Cleanroom Research Laboratory, University of Texas at Dallas, Richardson, Texas, USA
| | - Jimin Maeng
- Department of Bioengineering, University of Texas at Dallas, Richardson, Texas, USA
| | - Stuart F Cogan
- Department of Bioengineering, University of Texas at Dallas, Richardson, Texas, USA
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18
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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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19
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Eles JR, Kozai TDY. In vivo imaging of calcium and glutamate responses to intracortical microstimulation reveals distinct temporal responses of the neuropil and somatic compartments in layer II/III neurons. Biomaterials 2020; 234:119767. [PMID: 31954232 DOI: 10.1016/j.biomaterials.2020.119767] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Revised: 12/22/2019] [Accepted: 01/05/2020] [Indexed: 02/07/2023]
Abstract
OBJECTIVE Intracortical microelectrode implants can generate a tissue response hallmarked by glial scarring and neuron cell death within 100-150 μm of the biomaterial device. Many have proposed that any performance decline in intracortical microstimulation (ICMS) due to this foreign body tissue response could be offset by increasing the stimulation amplitude. The mechanisms of this approach are unclear, however, as there has not been consensus on how increasing amplitude affects the spatial and temporal recruitment patterns of ICMS. APPROACH We clarify these unknowns using in vivo two-photon imaging of mice transgenically expressing the calcium sensor GCaMP6s in Thy1 neurons or virally expressing the glutamate sensor iGluSnFr in neurons. Calcium and neurotransmitter activity are tracked in the neuronal somas and neuropil during long-train stimulation in Layer II/III of somatosensory cortex. MAIN RESULTS Neural calcium activity and glutamate release are dense and strongest within 20-40 μm around the electrode, falling off with distance from the electrode. Neuronal calcium increases with higher amplitude stimulations. During prolonged stimulation trains, a sub-population of somas fail to maintain calcium activity. Interestingly, neuropil calcium activity is 3-fold less correlated to somatic calcium activity for cells that drop-out during the long stimulation train compared to cells that sustain activity throughout the train. Glutamate release is apparent only within 20 μm of the electrode and is sustained for at least 10s after cessation of the 15 and 20 μA stimulation train, but not lower amplitudes. SIGNIFICANCE These results demonstrate that increasing amplitude can increase the radius and intensity of neural recruitment, but it also alters the temporal response of some neurons. Further, dense glutamate release is highest within the first 20 μm of the electrode site even at high amplitudes, suggesting that there may be spatial limitations to the amplitude parameter space. The glutamate elevation outlasts stimulation, suggesting that high-amplitude stimulation may affect neurotransmitter re-uptake. This ultimately suggests that increasing the amplitude of ICMS device stimulation may fundamentally alter the temporal neural response, which could have implications for using amplitude to improve the ICMS effect or "offset" the effects of glial scarring.
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Affiliation(s)
- James R Eles
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA
| | - Takashi D Y Kozai
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA; Center for the Neural Basis of Cognition, University of Pittsburgh, Carnegie Mellon University, Pittsburgh, PA, USA; Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA, USA; McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA, USA; NeuroTech Center, University of Pittsburgh Brain Institute, Pittsburgh, PA, USA.
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20
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Yang W, Gong Y, Li W. A Review: Electrode and Packaging Materials for Neurophysiology Recording Implants. Front Bioeng Biotechnol 2020; 8:622923. [PMID: 33585422 PMCID: PMC7873964 DOI: 10.3389/fbioe.2020.622923] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Accepted: 12/10/2020] [Indexed: 01/28/2023] Open
Abstract
To date, a wide variety of neural tissue implants have been developed for neurophysiology recording from living tissues. An ideal neural implant should minimize the damage to the tissue and perform reliably and accurately for long periods of time. Therefore, the materials utilized to fabricate the neural recording implants become a critical factor. The materials of these devices could be classified into two broad categories: electrode materials as well as packaging and substrate materials. In this review, inorganic (metals and semiconductors), organic (conducting polymers), and carbon-based (graphene and carbon nanostructures) electrode materials are reviewed individually in terms of various neural recording devices that are reported in recent years. Properties of these materials, including electrical properties, mechanical properties, stability, biodegradability/bioresorbability, biocompatibility, and optical properties, and their critical importance to neural recording quality and device capabilities, are discussed. For the packaging and substrate materials, different material properties are desired for the chronic implantation of devices in the complex environment of the body, such as biocompatibility and moisture and gas hermeticity. This review summarizes common solid and soft packaging materials used in a variety of neural interface electrode designs, as well as their packaging performances. Besides, several biopolymers typically applied over the electrode package to reinforce the mechanical rigidity of devices during insertion, or to reduce the immune response and inflammation at the device-tissue interfaces are highlighted. Finally, a benchmark analysis of the discussed materials and an outlook of the future research trends are concluded.
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Affiliation(s)
- Weiyang Yang
- Microtechnology Lab, Department of Electrical and Computer Engineering, Michigan State University, East Lansing, MI, United States
| | - Yan Gong
- Microtechnology Lab, Department of Electrical and Computer Engineering, Michigan State University, East Lansing, MI, United States
| | - Wen Li
- Microtechnology Lab, Department of Electrical and Computer Engineering, Michigan State University, East Lansing, MI, United States
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21
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Krukiewicz K, Kobus D, Turczyn R, Erfurt K, Chrobok A, Biggs MJ. Low resistance, highly corrugated structures based on poly(3,4-ethylenedioxythiophene) doped with a d-glucopyranoside-derived ionic liquid. Electrochem commun 2020. [DOI: 10.1016/j.elecom.2019.106616] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
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22
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Ferguson M, Sharma D, Ross D, Zhao F. A Critical Review of Microelectrode Arrays and Strategies for Improving Neural Interfaces. Adv Healthc Mater 2019; 8:e1900558. [PMID: 31464094 PMCID: PMC6786932 DOI: 10.1002/adhm.201900558] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Revised: 07/25/2019] [Indexed: 12/19/2022]
Abstract
Though neural interface systems (NISs) can provide a potential solution for mitigating the effects of limb loss and central nervous system damage, the microelectrode array (MEA) component of NISs remains a significant limiting factor to their widespread clinical applications. Several strategies can be applied to MEA designs to increase their biocompatibility. Herein, an overview of NISs and their applications is provided, along with a detailed discussion of strategies for alleviating the foreign body response (FBR) and abnormalities seen at the interface of MEAs and the brain tissue following MEA implantation. Various surface modifications, including natural/synthetic surface coatings, hydrogels, and topography alterations, have shown to be highly successful in improving neural cell adhesion, reducing gliosis, and increasing MEA longevity. Different MEA surface geometries, such as those seen in the Utah and Michigan arrays, can help alleviate the resultant FBR by reducing insertion damage, while providing new avenues for improving MEA recording performance and resolution. Increasing overall flexibility of MEAs as well as reducing their stiffness is also shown to reduce MEA induced micromotion along with FBR severity. By combining multiple different properties into a single MEA, the severity and duration of an FBR postimplantation can be reduced substantially.
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Affiliation(s)
- Morgan Ferguson
- Department of Biomedical Engineering, Michigan Technological University, 1400 Townsend Dr., Houghton, MI 49931
| | - Dhavan Sharma
- Department of Biomedical Engineering, Michigan Technological University, 1400 Townsend Dr., Houghton, MI 49931
| | - David Ross
- Department of Biomedical Engineering, Michigan Technological University, 1400 Townsend Dr., Houghton, MI 49931
| | - Feng Zhao
- Department of Biomedical Engineering, Michigan Technological University, 1400 Townsend Dr., Houghton, MI 49931
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23
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Zheng X, Woeppel KM, Griffith AY, Chang E, Looker MJ, Fisher LE, Clapsaddle BJ, Cui XT. Soft Conducting Elastomer for Peripheral Nerve Interface. Adv Healthc Mater 2019; 8:e1801311. [PMID: 30843365 DOI: 10.1002/adhm.201801311] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Revised: 01/24/2019] [Indexed: 12/17/2022]
Abstract
State-of-the-art intraneural electrodes made from silicon or polyimide substrates have shown promise in selectively modulating efferent and afferent activity in the peripheral nervous system. However, when chronically implanted, these devices trigger a multiphase foreign body response ending in device encapsulation. The presence of encapsulation increases the distance between the electrode and the excitable tissue, which not only reduces the recordable signal amplitude but also requires increased current to activate nearby axons. Herein, this study reports a novel conducting polymer based intraneural electrode which has Young's moduli similar to that of nerve tissue. The study first describes material optimization of the soft wire conductive matrix and evaluates their mechanical and electrochemical properties. Second, the study demonstrates 3T3 cell survival when cultured with media eluted from the soft wires. Third, the study presents acute in vivo functionality for stimulation of peripheral nerves to evoke force and compound muscle action potential in a rat model. Furthermore, comprehensive histological analyses show that soft wires elicit significantly less scar tissue encapsulation, less changes to axon size, density and morphology, and reduced macrophage activation compared to polyimide implants in the sciatic nerves at 1 month postimplantation.
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Affiliation(s)
- Xin Zheng
- Department of Bioengineering, University of Pittsburgh, 3501 Fifth Ave., Pittsburgh, PA, 15213, USA
| | - Kevin M Woeppel
- Department of Bioengineering, University of Pittsburgh, 3501 Fifth Ave., Pittsburgh, PA, 15213, USA
| | - Azante Y Griffith
- Department of Bioengineering, University of Pittsburgh, 3501 Fifth Ave., Pittsburgh, PA, 15213, USA
| | - Emily Chang
- TDA Research Inc., 12345 W. 52nd Street, Wheat Ridge, CO, 80033, USA
| | - Michael J Looker
- TDA Research Inc., 12345 W. 52nd Street, Wheat Ridge, CO, 80033, USA
| | - Lee E Fisher
- Department of Physical Medicine and Rehabilitation, Department of Bioengineering, University of Pittsburgh, 3250 Fifth Ave., Pittsburgh, PA, 15213, USA
| | | | - Xinyan Tracy Cui
- Department of Bioengineering, University of Pittsburgh, 3501 Fifth Ave., Pittsburgh, PA, 15213, USA
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Krukiewicz K, Kowalik A, Czerwinska-Glowka D, Biggs MJ. Electrodeposited poly(3,4-ethylenedioxypyrrole) films as neural interfaces: Cytocompatibility and electrochemical studies. Electrochim Acta 2019. [DOI: 10.1016/j.electacta.2019.02.023] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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25
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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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26
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Lee D, Moon HC, Tran BT, Kwon DH, Kim YH, Jung SD, Joo JH, Park YS. Characterization of Tetrodes Coated with Au Nanoparticles (AuNPs) and PEDOT and Their Application to Thalamic Neural Signal Detection in vivo. Exp Neurobiol 2019; 27:593-604. [PMID: 30636908 PMCID: PMC6318560 DOI: 10.5607/en.2018.27.6.593] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Revised: 11/12/2018] [Accepted: 11/16/2018] [Indexed: 11/27/2022] Open
Abstract
Tetrodes, consisting of four twisted micro-wires can simultaneously record the number of neurons in the brain. To improve the quality of neuronal activity detection, the tetrode tips should be modified to increase the surface area and lower the impedance properties. In this study, tetrode tips were modified by the electrodeposition of Au nanoparticles (AuNPs) and dextran (Dex) doped poly (3,4-ethylenedioxythiophene) (PEDOT). The electrochemical properties were measured using electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). A decrease in the impedance value from 4.3 MΩ to 13 kΩ at 1 kHz was achieved by the modified tetrodes. The cathodic charge storage capacity (CSCC) of AuNPs-PEDOT deposited tetrodes was 4.5 mC/cm2, as determined by CV measurements. The tetrodes that were electroplated with AuNPs and PEDOT exhibited an increased surface area, which reduced the tetrode impedance. In vivo recording in the ventral posterior medial (VPM) nucleus of the thalamus was performed to investigate the single-unit activity in normal rats. To evaluate the recording performance of modified tetrodes, spontaneous spike signals were recorded. The values of the L-ratio, isolation distance and signal-to-noise (SNR) confirmed that electroplating the tetrode surface with AuNPs and PEDOT improved the recording performance, and these parameters could be used to effectively quantify the spikes of each cluster.
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Affiliation(s)
- Daae Lee
- Department of Advanced Materials Engineering, Chungbuk National University, Cheongju 28644, Korea
| | - Hyeong Cheol Moon
- Department of Neurosurgery, Chungbuk National University Hospital, Cheongju 28644, Korea.,Department of Neurosurgery, Chungbuk National University, Cheongju 28644, Korea
| | - Bao-Tram Tran
- Department of Neurosurgery, Chungbuk National University, Cheongju 28644, Korea
| | - Dae-Hyuk Kwon
- Neuroscience Research Institute, Brain-Bio center, University of Suwon, Hwaseong 18323, Korea
| | - Yong Hee Kim
- Synaptic Devices Research Section, Electronics and Telecommunications Research Institute, Daejeon 34129, Korea
| | - Sang-Don Jung
- Synaptic Devices Research Section, Electronics and Telecommunications Research Institute, Daejeon 34129, Korea
| | - Jong Hoon Joo
- Department of Advanced Materials Engineering, Chungbuk National University, Cheongju 28644, Korea
| | - Young Seok Park
- Department of Neurosurgery, Chungbuk National University Hospital, Cheongju 28644, Korea.,Department of Neurosurgery, Chungbuk National University, Cheongju 28644, Korea
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27
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Qi X, Du ZJ, Zhu L, Liu X, Xu H, Zhou Z, Zhong C, Li S, Wang L, Zhang Z. The Glutamatergic Postrhinal Cortex-Ventrolateral Orbitofrontal Cortex Pathway Regulates Spatial Memory Retrieval. Neurosci Bull 2019; 35:447-460. [PMID: 30604280 DOI: 10.1007/s12264-018-0325-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Accepted: 09/08/2018] [Indexed: 12/11/2022] Open
Abstract
A deficit in spatial memory has been taken as an early predictor of Alzheimer's disease (AD) or mild cognitive impairment (MCI). The uncinate fasciculus (UF) is a long-range white-matter tract that connects the anterior temporal lobe with the orbitofrontal cortex (OFC) in primates. Previous studies have shown that the UF impairment associated with spatial memory deficits may be an important pathological change in aging and AD, but its exact role in spatial memory is not well understood. The pathway arising from the postrhinal cortex (POR) and projecting to the ventrolateral orbitofrontal cortex (vlOFC) performs most of the functions of the UF in rodents. Although the literature suggests an association between spatial memory and the regions connected by the POR-vlOFC pathway, the function of the pathway in spatial memory is relatively unknown. To further illuminate the function of the UF in spatial memory, we dissected the POR-vlOFC pathway in mice. We determined that the POR-vlOFC pathway is a glutamatergic structure, and that glutamatergic neurons in the POR regulate spatial memory retrieval. We also demonstrated that the POR-vlOFC pathway specifically transmits spatial information to participate in memory retrieval. These findings provide a deeper understanding of UF function and dysfunction related to disorders of memory, as in MCI and AD.
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Affiliation(s)
- Xinyang Qi
- Department of Neurology, Affiliated ZhongDa Hospital, Institute of Neuropsychiatry, School of Medicine, Southeast University, Nanjing, 210009, China
| | - Zhanhong Jeff Du
- Shenzhen Key Lab of Neuropsychiatric Modulation and Collaborative Innovation Center for Brain Science, Chinese Academy of Sciences (CAS) Center for Excellence in Brain Science and Intelligence Technology, the Brain Cognition and Brain Disease Institute for Collaboration Research of the Shenzhen Institutes of Advanced Technology at the CAS and the McGovern Institute at Massachusetts Institute of Technology, Shenzhen, 518055, China
| | - Lin Zhu
- Department of Neurology, Affiliated ZhongDa Hospital, Institute of Neuropsychiatry, School of Medicine, Southeast University, Nanjing, 210009, China
| | - Xuemei Liu
- Shenzhen Key Lab of Neuropsychiatric Modulation and Collaborative Innovation Center for Brain Science, Chinese Academy of Sciences (CAS) Center for Excellence in Brain Science and Intelligence Technology, the Brain Cognition and Brain Disease Institute for Collaboration Research of the Shenzhen Institutes of Advanced Technology at the CAS and the McGovern Institute at Massachusetts Institute of Technology, Shenzhen, 518055, China
| | - Hua Xu
- Department of Neurology, Affiliated ZhongDa Hospital, Institute of Neuropsychiatry, School of Medicine, Southeast University, Nanjing, 210009, China
| | - Zheng Zhou
- Shenzhen Key Lab of Neuropsychiatric Modulation and Collaborative Innovation Center for Brain Science, Chinese Academy of Sciences (CAS) Center for Excellence in Brain Science and Intelligence Technology, the Brain Cognition and Brain Disease Institute for Collaboration Research of the Shenzhen Institutes of Advanced Technology at the CAS and the McGovern Institute at Massachusetts Institute of Technology, Shenzhen, 518055, China
| | - Cheng Zhong
- Shenzhen Key Lab of Neuropsychiatric Modulation and Collaborative Innovation Center for Brain Science, Chinese Academy of Sciences (CAS) Center for Excellence in Brain Science and Intelligence Technology, the Brain Cognition and Brain Disease Institute for Collaboration Research of the Shenzhen Institutes of Advanced Technology at the CAS and the McGovern Institute at Massachusetts Institute of Technology, Shenzhen, 518055, China
| | - Shijiang Li
- Department of Biophysics, Medical College of Wisconsin, Milwaukee, WI, 53226, USA
| | - Liping Wang
- Shenzhen Key Lab of Neuropsychiatric Modulation and Collaborative Innovation Center for Brain Science, Chinese Academy of Sciences (CAS) Center for Excellence in Brain Science and Intelligence Technology, the Brain Cognition and Brain Disease Institute for Collaboration Research of the Shenzhen Institutes of Advanced Technology at the CAS and the McGovern Institute at Massachusetts Institute of Technology, Shenzhen, 518055, China.
| | - Zhijun Zhang
- Department of Neurology, Affiliated ZhongDa Hospital, Institute of Neuropsychiatry, School of Medicine, Southeast University, Nanjing, 210009, China. .,Shenzhen Key Lab of Neuropsychiatric Modulation and Collaborative Innovation Center for Brain Science, Chinese Academy of Sciences (CAS) Center for Excellence in Brain Science and Intelligence Technology, the Brain Cognition and Brain Disease Institute for Collaboration Research of the Shenzhen Institutes of Advanced Technology at the CAS and the McGovern Institute at Massachusetts Institute of Technology, Shenzhen, 518055, China.
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28
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Won SM, Song E, Zhao J, Li J, Rivnay J, Rogers JA. Recent Advances in Materials, Devices, and Systems for Neural Interfaces. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2018; 30:e1800534. [PMID: 29855089 DOI: 10.1002/adma.201800534] [Citation(s) in RCA: 85] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Revised: 02/28/2018] [Indexed: 06/08/2023]
Abstract
Technologies capable of establishing intimate, long-lived optical/electrical interfaces to neural systems will play critical roles in neuroscience research and in the development of nonpharmacological treatments for neurological disorders. The development of high-density interfaces to 3D populations of neurons across entire tissue systems in living animals, including human subjects, represents a grand challenge for the field, where advanced biocompatible materials and engineered structures for electrodes and light emitters will be essential. This review summarizes recent progress in these directions, with an emphasis on the most promising demonstrated concepts, materials, devices, and systems. The article begins with an overview of electrode materials with enhanced electrical and/or mechanical performance, in forms ranging from planar films, to micro/nanostructured surfaces, to 3D porous frameworks and soft composites. Subsequent sections highlight integration with active materials and components for multiplexed addressing, local amplification, wireless data transmission, and power harvesting, with multimodal operation in soft, shape-conformal systems. These advances establish the foundations for scalable architectures in optical/electrical neural interfaces of the future, where a blurring of the lines between biotic and abiotic systems will catalyze profound progress in neuroscience research and in human health/well-being.
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Affiliation(s)
- Sang Min Won
- Department of Electrical and Computer Engineering, Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana Champaign, Urbana, IL, 61801, USA
| | - Enming Song
- Department of Materials Science and Engineering, Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana Champaign, Northwestern University, Evanston, IL, 60208, USA
| | - Jianing Zhao
- Department of Mechanical Science and Engineering, Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana Champaign, Urbana, IL, 61801, USA
| | - Jinghua Li
- Department of Materials Science and Engineering, Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana Champaign, Northwestern University, Evanston, IL, 60208, USA
| | - Jonathan Rivnay
- Department of Biomedical Engineering, Simpson Querrey Institute for Nanobiotechnology, Northwestern University, Evanston, IL, 60208, USA
| | - John A Rogers
- Center for Bio-Integrated Electronics, Department of Materials Science and Engineering, Biomedical Engineering, Chemistry, Mechanical Engineering, Electrical Engineering and Computer Science, and Neurological Surgery, Simpson Querrey Institute for Nano/biotechnology, McCormick School of Engineering and Feinberg School of Medicine, Northwestern University, Evanston, IL, 60208, USA
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29
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Shoffstall AJ, Capadona JR. Bioinspired materials and systems for neural interfacing. CURRENT OPINION IN BIOMEDICAL ENGINEERING 2018. [DOI: 10.1016/j.cobme.2018.05.002] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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30
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Du ZJ, Bi GQ, Cui XT. Electrically Controlled Neurochemical Release from Dual-Layer Conducting Polymer Films for Precise Modulation of Neural Network Activity in Rat Barrel Cortex. ADVANCED FUNCTIONAL MATERIALS 2018; 28:1703988. [PMID: 30467460 PMCID: PMC6242295 DOI: 10.1002/adfm.201703988] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Implantable microelectrode arrays (MEAs) are important tools for investigating functional neural circuits and treating neurological diseases. Precise modulation of neural activity may be achieved by controlled delivery of neurochemicals directly from coatings on MEA electrode sites. In this study, a novel dual-layer conductive polymer/acid functionalized carbon nanotube (fCNT) microelectrode coating is developed to better facilitate the loading and controlled delivery of the neurochemical 6,7-dinitroquinoxaline-2,3-dione (DNQX). The base layer coating is consisted of poly(3,4-ethylenedioxythiophene/fCNT and the top layer is consisted of polypyrrole/fCNT/DNQX. The dual-layer coating is capable of both loading and electrically releasing DNQX and the release dynamic is characterized with fluorescence microscopy and mathematical modeling. In vivo DNQX release is demonstrated in rat somatosensory cortex. Sensory-evoked neural activity is immediately (<1s) and locally (<446 µm) suppressed by electrically triggered DNQX release. Furthermore, a single DNQX-loaded, dual-layer coating is capable of inducing effective neural inhibition for at least 26 times without observable degradation in efficacy. Incorporation of the novel drug releasing coating onto individual MEA electrodes offers many advantages over alternative methods by increasing spatial-temporal precision and improving drug selection flexibility without increasing the device's size.
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Affiliation(s)
- Zhanhong Jeff Du
- Department of Bioengineering, University of Pittsburgh, 5057 Biomedical Science Tower 3, 3501 Fifth Avenue, Pittsburgh, PA 15260, USA
| | - Guo-Qiang Bi
- Hefei National Laboratory for Physical Sciences at the Microscale, CAS Center for Excellence in Brain Science and Intelligence, Technology and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Xinyan Tracy Cui
- Department of Bioengineering, University of Pittsburgh, 5057 Biomedical Science Tower 3, 3501 Fifth Avenue, Pittsburgh, PA 15260, USA
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31
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Zhi B, Song Q, Mao Y. Vapor deposition of polyionic nanocoatings for reduction of microglia adhesion. RSC Adv 2018; 8:4779-4785. [PMID: 35539514 PMCID: PMC9077851 DOI: 10.1039/c7ra12728f] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2017] [Accepted: 01/01/2018] [Indexed: 11/29/2022] Open
Abstract
Polyionics have great potential in improving the performance of neural probes by regulating microglial response. With the shrinkage of microelectrode size and increase in device complexity, challenges arise during liquid-based synthesis of polyionic compounds on neural probes. Nanocoatings of polyionics, with highly crosslinked bulk structure and abundant ionic functional groups on the surface, were synthesized using a process combining chemical vapor deposition and free radical polymerization. Both conformal surface engineering of neural microelectrodes and facile tailoring of surface ionic composition was achieved using this single-step vapor-based method. Adhesion of microglia was reduced on all the polyionic modified surfaces after a seven-day in vitro test, and polyionics with mixed charges presented much lower microglial adhesion than surfaces with single charges. Laminin adsorption on polyionics with mixed charges was significantly reduced due to the surface electrical neutrality and the enhanced wettability. These findings provide valuable information towards the development of neural probes with enhanced biocompatibility and signal stability.
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Affiliation(s)
- Bin Zhi
- Department of Biosystems Engineering, Oklahoma State University Stillwater Oklahoma 74078 USA
| | - Qing Song
- Department of Biosystems Engineering, Oklahoma State University Stillwater Oklahoma 74078 USA
| | - Yu Mao
- Department of Biosystems Engineering, Oklahoma State University Stillwater Oklahoma 74078 USA
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32
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Du ZJ, Kolarcik CL, Kozai TDY, Luebben SD, Sapp SA, Zheng XS, Nabity JA, Cui XT. Ultrasoft microwire neural electrodes improve chronic tissue integration. Acta Biomater 2017; 53:46-58. [PMID: 28185910 DOI: 10.1016/j.actbio.2017.02.010] [Citation(s) in RCA: 109] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2016] [Revised: 02/02/2017] [Accepted: 02/05/2017] [Indexed: 12/11/2022]
Abstract
Chronically implanted neural multi-electrode arrays (MEA) are an essential technology for recording electrical signals from neurons and/or modulating neural activity through stimulation. However, current MEAs, regardless of the type, elicit an inflammatory response that ultimately leads to device failure. Traditionally, rigid materials like tungsten and silicon have been employed to interface with the relatively soft neural tissue. The large stiffness mismatch is thought to exacerbate the inflammatory response. In order to minimize the disparity between the device and the brain, we fabricated novel ultrasoft electrodes consisting of elastomers and conducting polymers with mechanical properties much more similar to those of brain tissue than previous neural implants. In this study, these ultrasoft microelectrodes were inserted and released using a stainless steel shuttle with polyethyleneglycol (PEG) glue. The implanted microwires showed functionality in acute neural stimulation. When implanted for 1 or 8weeks, the novel soft implants demonstrated significantly reduced inflammatory tissue response at week 8 compared to tungsten wires of similar dimension and surface chemistry. Furthermore, a higher degree of cell body distortion was found next to the tungsten implants compared to the polymer implants. Our results support the use of these novel ultrasoft electrodes for long term neural implants. STATEMENT OF SIGNIFICANCE One critical challenge to the translation of neural recording/stimulation electrode technology to clinically viable devices for brain computer interface (BCI) or deep brain stimulation (DBS) applications is the chronic degradation of device performance due to the inflammatory tissue reaction. While many hypothesize that soft and flexible devices elicit reduced inflammatory tissue responses, there has yet to be a rigorous comparison between soft and stiff implants. We have developed an ultra-soft microelectrode with Young's modulus lower than 1MPa, closely mimicking the brain tissue modulus. Here, we present a rigorous histological comparison of this novel ultrasoft electrode and conventional stiff electrode with the same size, shape and surface chemistry, implanted in rat brains for 1-week and 8-weeks. Significant improvement was observed for ultrasoft electrodes, including inflammatory tissue reaction, electrode-tissue integration as well as mechanical disturbance to nearby neurons. A full spectrum of new techniques were developed in this study, from insertion shuttle to in situ sectioning of the microelectrode to automated cell shape analysis, all of which should contribute new methods to the field. Finally, we showed the electrical functionality of the ultrasoft electrode, demonstrating the potential of flexible neural implant devices for future research and clinical use.
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Affiliation(s)
- Zhanhong Jeff Du
- Department of Bioengineering, University of Pittsburgh, PA, USA; Center for the Neural Basis of Cognition, University of Pittsburgh, PA, USA; McGowan Institute for Regenerative Medicine, University of Pittsburgh, PA, USA; Shenzhen Key Lab of Neuropsychiatric Modulation, CAS Center for Excellence in Brain Science, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Christi L Kolarcik
- Department of Bioengineering, University of Pittsburgh, PA, USA; Center for the Neural Basis of Cognition, University of Pittsburgh, PA, USA; McGowan Institute for Regenerative Medicine, University of Pittsburgh, PA, USA; Systems Neuroscience Institute, University of Pittsburgh, PA, USA
| | - Takashi D Y Kozai
- Department of Bioengineering, University of Pittsburgh, PA, USA; Center for the Neural Basis of Cognition, University of Pittsburgh, PA, USA; McGowan Institute for Regenerative Medicine, University of Pittsburgh, PA, USA; NeuroTech Center of Brain Institute, University of Pittsburgh, PA, USA
| | | | | | - Xin Sally Zheng
- Department of Bioengineering, University of Pittsburgh, PA, USA
| | - James A Nabity
- Department of Aerospace Engineering Sciences, University of Colorado, Boulder, CO,USA
| | - X Tracy Cui
- Department of Bioengineering, University of Pittsburgh, PA, USA; Center for the Neural Basis of Cognition, University of Pittsburgh, PA, USA; McGowan Institute for Regenerative Medicine, University of Pittsburgh, PA, USA.
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Taylor IM, Du Z, Bigelow ET, Eles JR, Horner AR, Catt KA, Weber SG, Jamieson BG, Cui XT. Aptamer-functionalized neural recording electrodes for the direct measurement of cocaine in vivo. J Mater Chem B 2017; 5:2445-2458. [PMID: 28729901 PMCID: PMC5512874 DOI: 10.1039/c7tb00095b] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Cocaine is a highly addictive psychostimulant that acts through competitive inhibition of the dopamine transporter. In order to fully understand the region specific neuropathology of cocaine abuse and addiction, it is unequivocally necessary to develop cocaine sensing technology capable of directly measuring real-time cocaine transient events local to different brain regions throughout the pharmacokinetic time course of exposure. We have developed an electrochemical aptamer-based in vivo cocaine sensor on a silicon based neural recording probe platform capable of directly measuring cocaine from discrete brain locations using square wave voltammetry (SWV). The sensitivity of the sensor for cocaine follows a modified exponential Langmuir model relationship and complete aptamer-target binding occurs in < 2 sec and unbinding in < 4 sec. The resulting temporal resolution is a 75X increase from traditional microdialysis sampling methods. When implanted in the rat dorsal striatum, the cocaine sensor exhibits stable SWV signal drift (modeled using a logarithmic exponential equation) and is capable of measuring real-time in vivo response to repeated local cocaine infusion as well as systemic IV cocaine injection. The in vivo sensor is capable of obtaining reproducible measurements over a period approaching 3 hours, after which signal amplitude significantly decreases likely due to tissue encapsulation. Finally, aptamer functionalized neural recording probes successfully detect spontaneous and evoked neural activity in the brain. This dual functionality makes the cocaine sensor a powerful tool capable of monitoring both biochemical and electrophysiological signals with high spatial and temporal resolution.
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Affiliation(s)
- I. Mitch Taylor
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Zhanhong Du
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA 15261, USA
- Shenzhen Key Lab of Neuropsychiatric Modulation and Collaborative Innovation Center for Brain Science, CAS Center for Excellence in Brain Science, Shenzhen Institute of Advanced Technologies, Chinese Academy of Sciences, Shenzhen, 518055, China
| | | | - James R. Eles
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Anthony R. Horner
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Kasey A. Catt
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Stephen G. Weber
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | | | - X. Tracy Cui
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA 15261, USA
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