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Seufert L, Elmahmoudy M, Theunis C, Lienemann S, Li Y, Mohammadi M, Boda U, Carnicer-Lombarte A, Kroon R, Persson POÅ, Rahmanudin A, Donahue MJ, Farnebo S, Tybrandt K. Stretchable Tissue-Like Gold Nanowire Composites with Long-Term Stability for Neural Interfaces. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2024:e2402214. [PMID: 38944890 DOI: 10.1002/smll.202402214] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2024] [Revised: 06/20/2024] [Indexed: 07/02/2024]
Abstract
Soft and stretchable nanocomposites can match the mechanical properties of neural tissue, thereby minimizing foreign body reactions to provide optimal stimulation and recording specificity. Soft materials for neural interfaces should simultaneously fulfill a wide range of requirements, including low Young's modulus (<<1 MPa), stretchability (≥30%), high conductivity (>> 1000 S cm-1), biocompatibility, and chronic stability (>> 1 year). Current nanocomposites do not fulfill the above requirements, in particular not the combination of softness and high conductivity. Here, this challenge is addressed by developing a scalable and robust synthesis route based on polymeric reducing agents for smooth, high-aspect ratio gold nanowires (AuNWs) of controllable dimensions with excellent biocompatibility. AuNW-silicone composites show outstanding performance with nerve-like softness (250 kPa), high conductivity (16 000 S cm-1), and reversible stretchability. Soft multielectrode cuffs based on the composite achieve selective functional stimulation, recordings of sensory stimuli in rat sciatic nerves, and show an accelerated lifetime stability of >3 years. The scalable synthesis method provides a chemically stable alternative to the widely used AgNWs, thereby enabling new applications within electronics, biomedical devices, and electrochemistry.
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Affiliation(s)
- Laura Seufert
- Laboratory of Organic Electronics, Department of Science and Technology, Linköping University, Norrköping, 602 21, Sweden
| | - Mohammed Elmahmoudy
- Laboratory of Organic Electronics, Department of Science and Technology, Linköping University, Norrköping, 602 21, Sweden
| | - Charlotte Theunis
- Laboratory of Organic Electronics, Department of Science and Technology, Linköping University, Norrköping, 602 21, Sweden
| | - Samuel Lienemann
- Laboratory of Organic Electronics, Department of Science and Technology, Linköping University, Norrköping, 602 21, Sweden
| | - Yuyang Li
- Laboratory of Organic Electronics, Department of Science and Technology, Linköping University, Norrköping, 602 21, Sweden
| | - Mohsen Mohammadi
- Laboratory of Organic Electronics, Department of Science and Technology, Linköping University, Norrköping, 602 21, Sweden
| | - Ulrika Boda
- RISE Research Institutes of Sweden, Digital Systems, Smart Hardware, Printed, Bio- and Organic Electronics, Södra Grytsgatan 4, Norrköping, SE-602 33, Sweden
| | | | - Renee Kroon
- Laboratory of Organic Electronics, Department of Science and Technology, Linköping University, Norrköping, 602 21, Sweden
| | - Per O Å Persson
- Department of Physics, Chemistry and Biology, Linköping University, Linköping, 581 83, Sweden
| | - Aiman Rahmanudin
- Laboratory of Organic Electronics, Department of Science and Technology, Linköping University, Norrköping, 602 21, Sweden
| | - Mary J Donahue
- Laboratory of Organic Electronics, Department of Science and Technology, Linköping University, Norrköping, 602 21, Sweden
| | - Simon Farnebo
- Department of Hand Surgery, Plastic Surgery and Burns, Linköping University Hospital, Linköping, 581 85, Sweden
- Department of Biomedical and Clinical Sciences, Linköping University, Linköping, 581 85, Sweden
| | - Klas Tybrandt
- Laboratory of Organic Electronics, Department of Science and Technology, Linköping University, Norrköping, 602 21, Sweden
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Cuttaz EA, Bailey ZK, Chapman CAR, Goding JA, Green RA. Polymer Bioelectronics: A Solution for Both Stimulating and Recording Electrodes. Adv Healthc Mater 2024:e2304447. [PMID: 38775757 DOI: 10.1002/adhm.202304447] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2023] [Revised: 03/31/2024] [Indexed: 06/01/2024]
Abstract
The advent of closed-loop bionics has created a demand for electrode materials that are ideal for both stimulating and recording applications. The growing complexity and diminishing size of implantable devices for neural interfaces have moved beyond what can be achieved with conventional metallic electrode materials. Polymeric electrode materials are a recent development based on polymer composites of organic conductors such as conductive polymers. These materials present exciting new opportunities in the design and fabrication of next-generation electrode arrays which can overcome the electrochemical and mechanical limitations of conventional electrode materials. This review will examine the recent developments in polymeric electrode materials, their application as stimulating and recording electrodes in bionic devices, and their impact on the development of soft, conformal, and high-density neural interfaces.
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Affiliation(s)
- Estelle A Cuttaz
- Department of Bioengineering, Imperial College London, London, SW7 2BX, UK
| | - Zachary K Bailey
- Department of Bioengineering, Imperial College London, London, SW7 2BX, UK
| | - Christopher A R Chapman
- Department of Bioengineering, Imperial College London, London, SW7 2BX, UK
- School of Engineering and Materials Science, Queen Mary University of London, London, E1 4NS, UK
| | - Josef A Goding
- Department of Bioengineering, Imperial College London, London, SW7 2BX, UK
| | - Rylie A Green
- Department of Bioengineering, Imperial College London, London, SW7 2BX, UK
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3
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Rodilla BL, Arché-Núñez A, Ruiz-Gómez S, Domínguez-Bajo A, Fernández-González C, Guillén-Colomer C, González-Mayorga A, Rodríguez-Díez N, Camarero J, Miranda R, López-Dolado E, Ocón P, Serrano MC, Pérez L, González MT. Flexible metallic core-shell nanostructured electrodes for neural interfacing. Sci Rep 2024; 14:3729. [PMID: 38355737 PMCID: PMC10866994 DOI: 10.1038/s41598-024-53719-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Accepted: 02/04/2024] [Indexed: 02/16/2024] Open
Abstract
Electrodes with nanostructured surface have emerged as promising low-impedance neural interfaces that can avoid the charge-injection restrictions typically associated to microelectrodes. In this work, we propose a novel approximation, based on a two-step template assisted electrodeposition technique, to obtain flexible nanostructured electrodes coated with core-shell Ni-Au vertical nanowires. These nanowires benefit from biocompatibility of the Au shell exposed to the environment and the mechanical properties of Ni that allow for nanowires longer and more homogeneous in length than their only-Au counterparts. The nanostructured electrodes show impedance values, measured by electrochemical impedance spectroscopy (EIS), at least 9 times lower than those of flat reference electrodes. This ratio is in good accordance with the increased effective surface area determined both from SEM images and cyclic voltammetry measurements, evidencing that only Au is exposed to the medium. The observed EIS profile evolution of Ni-Au electrodes over 7 days were very close to those of Au electrodes and differently from Ni ones. Finally, the morphology, viability and neuronal differentiation of rat embryonic cortical cells cultured on Ni-Au NW electrodes were found to be similar to those on control (glass) substrates and Au NW electrodes, accompanied by a lower glial cell differentiation. This positive in-vitro neural cell behavior encourages further investigation to explore the tissue responses that the implantation of these nanostructured electrodes might elicit in healthy (damaged) neural tissues in vivo, with special emphasis on eventual tissue encapsulation.
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Affiliation(s)
- Beatriz L Rodilla
- Fundación IMDEA Nanociencia, Calle Faraday 9, 28049, Madrid, Spain
- Departamento de Física de Materiales, Universidad Complutense de Madrid, Plaza de las Ciencias S/N, 28040, Madrid, Spain
| | - Ana Arché-Núñez
- Fundación IMDEA Nanociencia, Calle Faraday 9, 28049, Madrid, Spain
| | - Sandra Ruiz-Gómez
- Max Planck Institute for Chemical Physics of Solids, Dresden, Germany
| | - Ana Domínguez-Bajo
- Instituto de Ciencia de Materiales de Madrid (ICMM), CSIC, Calle Sor Juana Inés de la Cruz 3, 28049, Madrid, Spain
- Animal Molecular and Cellular Biology group (AMCB), Louvain Institute of Biomolecular Science and Technology (LIBST), Université catholique de Louvain, Place Croix du Sud 5, 1348 , Louvain la Neuve, Belgium
| | | | | | | | | | - Julio Camarero
- Fundación IMDEA Nanociencia, Calle Faraday 9, 28049, Madrid, Spain
- Department de Física de la Materia Condensada and Instituto "Nicolás Cabrera", Universidad Autónoma de Madrid, 28049, Madrid, Spain
| | - Rodolfo Miranda
- Fundación IMDEA Nanociencia, Calle Faraday 9, 28049, Madrid, Spain
- Department de Física de la Materia Condensada and Instituto "Nicolás Cabrera", Universidad Autónoma de Madrid, 28049, Madrid, Spain
| | - Elisa López-Dolado
- Hospital Nacional de Parapléjicos, SESCAM, Finca la Peraleda S/N, 45071, Toledo, Spain
- Design and development of Biomaterials for Neural Regeneration, HNP-SESCAM, Associated Unit With CSIC Through ICMM, Finca La Peraleda S/N, 45071, Toledo, Spain
| | - Pilar Ocón
- Departamento de Química Física Aplicada, Universidad Autónoma de Madrid, 28049, Madrid, Spain
| | - María C Serrano
- Instituto de Ciencia de Materiales de Madrid (ICMM), CSIC, Calle Sor Juana Inés de la Cruz 3, 28049, Madrid, Spain
| | - Lucas Pérez
- Fundación IMDEA Nanociencia, Calle Faraday 9, 28049, Madrid, Spain
- Departamento de Física de Materiales, Universidad Complutense de Madrid, Plaza de las Ciencias S/N, 28040, Madrid, Spain
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4
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Yu A, Zhu M, Chen C, Li Y, Cui H, Liu S, Zhao Q. Implantable Flexible Sensors for Health Monitoring. Adv Healthc Mater 2024; 13:e2302460. [PMID: 37816513 DOI: 10.1002/adhm.202302460] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 10/05/2023] [Indexed: 10/12/2023]
Abstract
Flexible sensors, as a significant component of flexible electronics, have attracted great interest the realms of human-computer interaction and health monitoring due to their high conformability, adjustable sensitivity, and excellent durability. In comparison to wearable sensor-based in vitro health monitoring, the use of implantable flexible sensors (IFSs) for in vivo health monitoring offers more accurate and reliable vital sign information due to their ability to adapt and directly integrate with human tissue. IFSs show tremendous promise in the field of health monitoring, with unique advantages such as robust signal reading capabilities, lightweight design, flexibility, and biocompatibility. Herein, a review of IFSs for vital signs monitoring is detailly provided, highlighting the essential conditions for in vivo applications. As the prerequisites of IFSs, the stretchability and wireless self-powered properties of the sensor are discussed, with a special attention paid to the sensing materials which can maintain prominent biosafety (i.e., biocompatibility, biodegradability, bioresorbability). Furthermore, the applications of IFSs monitoring various parts of the body are described in detail, with a summary in brain monitoring, eye monitoring, and blood monitoring. Finally, the challenges as well as opportunities in the development of next-generation IFSs are presented.
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Affiliation(s)
- Aoxi Yu
- College of Electronic and Optical Engineering, and College of Flexible Electronics (Future Technology), Nanjing University of Posts and Telecommunications, 9 Wenyuan, Nanjing, 210023, P. R. China
| | - Mingye Zhu
- State Key Laboratory of Organic Electronics and Information Displays, and Jiangsu Key Laboratory for Biosensors, Institute of Advanced Materials (IAM), Nanjing University of Posts and Telecommunications, 9 Wenyuan Road, Nanjing, 210023, P. R. China
| | - Congkai Chen
- State Key Laboratory of Organic Electronics and Information Displays, and Jiangsu Key Laboratory for Biosensors, Institute of Advanced Materials (IAM), Nanjing University of Posts and Telecommunications, 9 Wenyuan Road, Nanjing, 210023, P. R. China
| | - Yang Li
- College of Electronic and Optical Engineering, and College of Flexible Electronics (Future Technology), Nanjing University of Posts and Telecommunications, 9 Wenyuan, Nanjing, 210023, P. R. China
| | - Haixia Cui
- State Key Laboratory of Organic Electronics and Information Displays, and Jiangsu Key Laboratory for Biosensors, Institute of Advanced Materials (IAM), Nanjing University of Posts and Telecommunications, 9 Wenyuan Road, Nanjing, 210023, P. R. China
| | - Shujuan Liu
- State Key Laboratory of Organic Electronics and Information Displays, and Jiangsu Key Laboratory for Biosensors, Institute of Advanced Materials (IAM), Nanjing University of Posts and Telecommunications, 9 Wenyuan Road, Nanjing, 210023, P. R. China
| | - Qiang Zhao
- College of Electronic and Optical Engineering, and College of Flexible Electronics (Future Technology), Nanjing University of Posts and Telecommunications, 9 Wenyuan, Nanjing, 210023, P. R. China
- State Key Laboratory of Organic Electronics and Information Displays, and Jiangsu Key Laboratory for Biosensors, Institute of Advanced Materials (IAM), Nanjing University of Posts and Telecommunications, 9 Wenyuan Road, Nanjing, 210023, P. R. China
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5
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Montoya G, Wagner K, Ryder G, Naseri ASZ, Faisal SN, Sencadas V, In Het Panhuis M, Spinks GM, Wallace GG, Alici G, Officer DL. Edge-Functionalized Graphene/Polydimethylsiloxane Composite Films for Flexible Neural Cuff Electrodes. ACS APPLIED MATERIALS & INTERFACES 2023; 15:38833-38845. [PMID: 37537952 DOI: 10.1021/acsami.3c07525] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/05/2023]
Abstract
The design of neural electrodes has changed in the past decade, driven mainly by the development of new materials that open the possibility of manufacturing electrodes with adaptable mechanical properties and promising electrical properties. In this paper, we report on the mechanical and electrochemical properties of a polydimethylsiloxane (PDMS) composite with edge-functionalized graphene (EFG) and demonstrate its potential for use in neural implants with the fabrication of a novel neural cuff electrode. We have shown that a 200 μm thick 1:1 EFG/PDMS composite film has a stretchability of up to 20%, a Young's modulus of 2.52 MPa, and a lifetime of more than 10000 mechanical cycles, making it highly suitable for interfacing with soft tissue. Electrochemical characterization of the EFG/PDMS composite film showed that the capacitance of the composite increased up to 35 times after electrochemical reduction, widening the electrochemical water window and remaining stable after soaking for 5 weeks in phosphate buffered saline. The electrochemically activated EFG/PDMS electrode had a 3 times increase in the charge injection capacity, which is more than double that of a commercial platinum-based neural cuff. Electrochemical and spectrochemical investigations supported the conclusion that this effect originated from the stable chemisorption of hydrogen on the graphene surface. The biocompatibility of the composite was confirmed with an in vitro cell culture study using mouse spinal cord cells. Finally, the potential of the EFG/PDMS composite was demonstrated with the fabrication of a novel neural cuff electrode, whose double-layered and open structured design increased the cuff stretchability up to 140%, well beyond that required for an operational neural cuff. In addition, the cuff design offers better integration with neural tissue and simpler nerve fiber installation and locking.
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Affiliation(s)
- Gerardo Montoya
- School of Mechanical, Materials, Mechatronic and Biomedical Engineering, University of Wollongong, Wollongong, NSW 2522, Australia
- ARC Centre of Excellence for Electromaterials Science, University of Wollongong, Wollongong, NSW 2522, Australia
| | - Klaudia Wagner
- ARC Centre of Excellence for Electromaterials Science, University of Wollongong, Wollongong, NSW 2522, Australia
- Intelligent Polymer Research Institute, University of Wollongong, Wollongong, NSW 2522, Australia
| | - Gregory Ryder
- Intelligent Polymer Research Institute, University of Wollongong, Wollongong, NSW 2522, Australia
| | - Aida Shoushtari Zadeh Naseri
- ARC Centre of Excellence for Electromaterials Science, University of Wollongong, Wollongong, NSW 2522, Australia
- Intelligent Polymer Research Institute, University of Wollongong, Wollongong, NSW 2522, Australia
| | - Shaikh Nayeem Faisal
- ARC Centre of Excellence for Electromaterials Science, University of Wollongong, Wollongong, NSW 2522, Australia
- Intelligent Polymer Research Institute, University of Wollongong, Wollongong, NSW 2522, Australia
| | - Vitor Sencadas
- School of Mechanical, Materials, Mechatronic and Biomedical Engineering, University of Wollongong, Wollongong, NSW 2522, Australia
| | - Marc In Het Panhuis
- ARC Centre of Excellence for Electromaterials Science, University of Wollongong, Wollongong, NSW 2522, Australia
- School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, NSW 2522, Australia
| | - Geoffrey M Spinks
- School of Mechanical, Materials, Mechatronic and Biomedical Engineering, University of Wollongong, Wollongong, NSW 2522, Australia
- ARC Centre of Excellence for Electromaterials Science, University of Wollongong, Wollongong, NSW 2522, Australia
- Intelligent Polymer Research Institute, University of Wollongong, Wollongong, NSW 2522, Australia
| | - Gordon G Wallace
- ARC Centre of Excellence for Electromaterials Science, University of Wollongong, Wollongong, NSW 2522, Australia
- Intelligent Polymer Research Institute, University of Wollongong, Wollongong, NSW 2522, Australia
| | - Gursel Alici
- School of Mechanical, Materials, Mechatronic and Biomedical Engineering, University of Wollongong, Wollongong, NSW 2522, Australia
- ARC Centre of Excellence for Electromaterials Science, University of Wollongong, Wollongong, NSW 2522, Australia
| | - David L Officer
- ARC Centre of Excellence for Electromaterials Science, University of Wollongong, Wollongong, NSW 2522, Australia
- Intelligent Polymer Research Institute, University of Wollongong, Wollongong, NSW 2522, Australia
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6
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Jain C, Surabhi P, Marathe K. Critical Review on the Developments in Polymer Composite Materials for Biomedical Implants. JOURNAL OF BIOMATERIALS SCIENCE, POLYMER EDITION 2022; 34:893-917. [PMID: 36369719 DOI: 10.1080/09205063.2022.2145870] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
There has been a lack of research for developing functional polymer composites for biomedical implants. Even though metals are widely used as implant materials, there is a need for developing polymer composites as implant materials because of the stress shielding effect that causes a lack of compatibility of metals with the human body. This review aims to bring out the latest developments in polymer composite materials for body implants and to emphasize the significance of polymer composites as a viable alternative to conventional materials used in the biomedical industry for ease of life. This review article explores the developments in functional polymer composites for biomedical applications and provides distinct divisions for their applications based on the part of the body where they are implanted. Each application has been covered in some detail. The various applications covered are bone transplants and bone regeneration, cardiovascular implants (stents), dental implants and restorative materials, neurological and spinal implants, and tendon and ligament replacement.
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Affiliation(s)
| | | | - Kumudinee Marathe
- Department of Chemical Engg, Institute of Chemical Technology, Matunga, Mumbai, Maharashtra, India 400019
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7
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Conductive fibers for biomedical applications. Bioact Mater 2022; 22:343-364. [PMID: 36311045 PMCID: PMC9588989 DOI: 10.1016/j.bioactmat.2022.10.014] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 09/12/2022] [Accepted: 10/07/2022] [Indexed: 11/26/2022] Open
Abstract
Bioelectricity has been stated as a key factor in regulating cell activity and tissue function in electroactive tissues. Thus, various biomedical electronic constructs have been developed to interfere with cell behaviors to promote tissue regeneration, or to interface with cells or tissue/organ surfaces to acquire physiological status via electrical signals. Benefiting from the outstanding advantages of flexibility, structural diversity, customizable mechanical properties, and tunable distribution of conductive components, conductive fibers are able to avoid the damage-inducing mechanical mismatch between the construct and the biological environment, in return to ensure stable functioning of such constructs during physiological deformation. Herein, this review starts by presenting current fabrication technologies of conductive fibers including wet spinning, microfluidic spinning, electrospinning and 3D printing as well as surface modification on fibers and fiber assemblies. To provide an update on the biomedical applications of conductive fibers and fiber assemblies, we further elaborate conductive fibrous constructs utilized in tissue engineering and regeneration, implantable healthcare bioelectronics, and wearable healthcare bioelectronics. To conclude, current challenges and future perspectives of biomedical electronic constructs built by conductive fibers are discussed.
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8
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Akouissi O, Lacour SP, Micera S, DeSimone A. A finite element model of the mechanical interactions between peripheral nerves and intrafascicular implants. J Neural Eng 2022; 19. [PMID: 35861557 DOI: 10.1088/1741-2552/ac7d0e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Accepted: 06/29/2022] [Indexed: 11/11/2022]
Abstract
Objective.Intrafascicular peripheral nerve implants are key components in the development of bidirectional neuroprostheses such as touch-enabled bionic limbs for amputees. However, the durability of such interfaces is hindered by the immune response following the implantation. Among the causes linked to such reaction, the mechanical mismatch between host nerve and implant is thought to play a decisive role, especially in chronic settings.Approach.Here we focus on modeling mechanical stresses induced on the peripheral nerve by the implant's micromotion using finite element analysis. Through multiple parametric sweeps, we analyze the role of the implant's material, geometry (aspect-ratio and shape), and surface coating, deriving a set of parameters for the design of better-integrated implants.Main results.Our results indicate that peripheral nerve implants should be designed and manufactured with smooth edges, using materials at most three orders of magnitude stiffer than the nerve, and with innovative geometries to redistribute micromotion-associated loads to less delicate parts of the nerve such as the epineurium.Significance.Overall, our model is a useful tool for the peripheral nerve implant designer that is mindful of the importance of implant mechanics for long term applications.
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Affiliation(s)
- Outman Akouissi
- Bertarelli Foundation Chair in Neuroprosthetic Technology, Laboratory for Soft Bioelectronic Interfaces, Neuro-X Institute, Ecole Polytechnique Fédérale de Lausanne (EPFL), Geneva, 1202, Switzerland.,Bertarelli Foundation Chair in Translational Neuroengineering, Translational Neural Engineering Laboratory, Neuro-X Institute, Ecole Polytechnique Fédérale de Lausanne (EPFL), Geneva, 1202, Switzerland
| | - Stéphanie P Lacour
- Bertarelli Foundation Chair in Neuroprosthetic Technology, Laboratory for Soft Bioelectronic Interfaces, Neuro-X Institute, Ecole Polytechnique Fédérale de Lausanne (EPFL), Geneva, 1202, Switzerland
| | - Silvestro Micera
- Bertarelli Foundation Chair in Translational Neuroengineering, Translational Neural Engineering Laboratory, Neuro-X Institute, Ecole Polytechnique Fédérale de Lausanne (EPFL), Geneva, 1202, Switzerland.,The Biorobotics Institute and Department of Excellence in Robotics & AI, Health Science Interdisciplinary Center, Scuola Superiore Sant'Anna, Pisa, Italy
| | - Antonio DeSimone
- The Biorobotics Institute and Department of Excellence in Robotics & AI, Health Science Interdisciplinary Center, Scuola Superiore Sant'Anna, Pisa, Italy.,SISSA-International School for Advanced Studies, 34136 Trieste, Italy
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Tringides CM, Mooney DJ. Materials for Implantable Surface Electrode Arrays: Current Status and Future Directions. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2022; 34:e2107207. [PMID: 34716730 DOI: 10.1002/adma.202107207] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Revised: 10/26/2021] [Indexed: 06/13/2023]
Abstract
Surface electrode arrays are mainly fabricated from rigid or elastic materials, and precisely manipulated ductile metal films, which offer limited stretchability. However, the living tissues to which they are applied are nonlinear viscoelastic materials, which can undergo significant mechanical deformation in dynamic biological environments. Further, the same arrays and compositions are often repurposed for vastly different tissues rather than optimizing the materials and mechanical properties of the implant for the target application. By first characterizing the desired biological environment, and then designing a technology for a particular organ, surface electrode arrays may be more conformable, and offer better interfaces to tissues while causing less damage. Here, the various materials used in each component of a surface electrode array are first reviewed, and then electrically active implants in three specific biological systems, the nervous system, the muscular system, and skin, are described. Finally, the fabrication of next-generation surface arrays that overcome current limitations is discussed.
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Affiliation(s)
- Christina M Tringides
- Harvard Program in Biophysics, Harvard University, Cambridge, MA, 02138, USA
- Harvard-MIT Division in Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Cambridge, MA, 02138, USA
| | - David J Mooney
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Cambridge, MA, 02138, USA
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, 02138, USA
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10
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Kiyotake EA, Martin MD, Detamore MS. Regenerative rehabilitation with conductive biomaterials for spinal cord injury. Acta Biomater 2022; 139:43-64. [PMID: 33326879 DOI: 10.1016/j.actbio.2020.12.021] [Citation(s) in RCA: 43] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 11/24/2020] [Accepted: 12/09/2020] [Indexed: 02/07/2023]
Abstract
The individual approaches of regenerative medicine efforts alone and rehabilitation efforts alone have not yet fully restored function after severe spinal cord injury (SCI). Regenerative rehabilitation may be leveraged to promote regeneration of the spinal cord tissue, and promote reorganization of the regenerated neural pathways and intact spinal circuits for better functional recovery for SCI. Conductive biomaterials may be a linchpin that empowers the synergy between regenerative medicine and rehabilitation approaches, as electrical stimulation applied to the spinal cord could facilitate neural reorganization. In this review, we discuss current regenerative medicine approaches in clinical trials and the rehabilitation, or neuromodulation, approaches for SCI, along with their respective translational limitations. Furthermore, we review the translational potential, in a surgical context, of conductive biomaterials (e.g., conductive polymers, carbon-based materials, metallic nanoparticle-based materials) as they pertain to SCI. While pre-formed scaffolds may be difficult to translate to human contusion SCIs, injectable composites that contain blended conductive components and can form within the injury may be more translational. However, given that there are currently no in vivo SCI studies that evaluated conductive materials combined with rehabilitation approaches, we discuss several limitations of conductive biomaterials, including demonstrating safety and efficacy, that will need to be addressed in the future for conductive biomaterials to become SCI therapeutics. Even so, the use of conductive biomaterials creates a synergistic opportunity to merge the fields of regenerative medicine and rehabilitation and redefine what regenerative rehabilitation means for the spinal cord. STATEMENT OF SIGNIFICANCE: For spinal cord injury (SCI), the individual approaches of regenerative medicine and rehabilitation are insufficient to fully restore functional recovery; however, the goal of regenerative rehabilitation is to combine these two disparate fields to maximize the functional outcomes. Concepts similar to regenerative rehabilitation for SCI have been discussed in several reviews, but for the first time, this review considers how conductive biomaterials may synergize the two approaches. We cover current regenerative medicine and rehabilitation approaches for SCI, and the translational advantages and disadvantages, in a surgical context, of conductive biomaterials used in biomedical applications that may be additionally applied to SCI. Furthermore, we identify the current limitations and translational challenges for conductive biomaterials before they may become therapeutics for SCI.
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11
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Vėbraitė I, Hanein Y. Soft Devices for High-Resolution Neuro-Stimulation: The Interplay Between Low-Rigidity and Resolution. FRONTIERS IN MEDICAL TECHNOLOGY 2022; 3:675744. [PMID: 35047928 PMCID: PMC8757739 DOI: 10.3389/fmedt.2021.675744] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Accepted: 05/14/2021] [Indexed: 12/27/2022] Open
Abstract
The field of neurostimulation has evolved over the last few decades from a crude, low-resolution approach to a highly sophisticated methodology entailing the use of state-of-the-art technologies. Neurostimulation has been tested for a growing number of neurological applications, demonstrating great promise and attracting growing attention in both academia and industry. Despite tremendous progress, long-term stability of the implants, their large dimensions, their rigidity and the methods of their introduction and anchoring to sensitive neural tissue remain challenging. The purpose of this review is to provide a concise introduction to the field of high-resolution neurostimulation from a technological perspective and to focus on opportunities stemming from developments in materials sciences and engineering to reduce device rigidity while optimizing electrode small dimensions. We discuss how these factors may contribute to smaller, lighter, softer and higher electrode density devices.
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Affiliation(s)
- Ieva Vėbraitė
- School of Electrical Engineering, Tel Aviv University, Tel Aviv, Israel
| | - Yael Hanein
- School of Electrical Engineering, Tel Aviv University, Tel Aviv, Israel
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12
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Berggren M, Głowacki ED, Simon DT, Stavrinidou E, Tybrandt K. In Vivo Organic Bioelectronics for Neuromodulation. Chem Rev 2022; 122:4826-4846. [PMID: 35050623 PMCID: PMC8874920 DOI: 10.1021/acs.chemrev.1c00390] [Citation(s) in RCA: 29] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
![]()
The nervous system
poses a grand challenge for integration with
modern electronics and the subsequent advances in neurobiology, neuroprosthetics,
and therapy which would become possible upon such integration. Due
to its extreme complexity, multifaceted signaling pathways, and ∼1
kHz operating frequency, modern complementary metal oxide semiconductor
(CMOS) based electronics appear to be the only technology platform
at hand for such integration. However, conventional CMOS-based electronics
rely exclusively on electronic signaling and therefore require an
additional technology platform to translate electronic signals into
the language of neurobiology. Organic electronics are just such a
technology platform, capable of converting electronic addressing into
a variety of signals matching the endogenous signaling of the nervous
system while simultaneously possessing favorable material similarities
with nervous tissue. In this review, we introduce a variety of organic
material platforms and signaling modalities specifically designed
for this role as “translator”, focusing especially on
recent implementation in in vivo neuromodulation.
We hope that this review serves both as an informational resource
and as an encouragement and challenge to the field.
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Affiliation(s)
- Magnus Berggren
- Laboratory of Organic Electronics, Department of Science and Technology, Linköping University, 601 74 Norrköping, Sweden
| | - Eric D Głowacki
- Laboratory of Organic Electronics, Department of Science and Technology, Linköping University, 601 74 Norrköping, Sweden.,Bioelectronics Materials and Devices, Central European Institute of Technology, Brno University of Technology, Purkyňova 656/123, 612 00 Brno, Czech Republic
| | - Daniel T Simon
- Laboratory of Organic Electronics, Department of Science and Technology, Linköping University, 601 74 Norrköping, Sweden
| | - Eleni Stavrinidou
- Laboratory of Organic Electronics, Department of Science and Technology, Linköping University, 601 74 Norrköping, Sweden
| | - Klas Tybrandt
- Laboratory of Organic Electronics, Department of Science and Technology, Linköping University, 601 74 Norrköping, Sweden
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13
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Song S, Kim KY, Lee SH, Kim KK, Lee K, Lee W, Jeon H, Ko SH. Recent Advances in 1D Nanomaterial‐Based Bioelectronics for Healthcare Applications. ADVANCED NANOBIOMED RESEARCH 2021. [DOI: 10.1002/anbr.202100111] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Affiliation(s)
- Sangmin Song
- Applied Nano and Thermal Science Lab Department of Mechanical Engineering Seoul National University 1 Gwanak-ro Gwanak-gu Seoul 151-742 Korea
- Center for Biomaterials Biomedical Research Institute Korea Institute of Science and Technology (KIST) 5, Hwarang-ro 14-gil Seongbuk-gu Seoul 02792 Korea
| | - Kyung Yeun Kim
- Applied Nano and Thermal Science Lab Department of Mechanical Engineering Seoul National University 1 Gwanak-ro Gwanak-gu Seoul 151-742 Korea
- Center for Biomaterials Biomedical Research Institute Korea Institute of Science and Technology (KIST) 5, Hwarang-ro 14-gil Seongbuk-gu Seoul 02792 Korea
| | - Sun Hee Lee
- Center for Biomaterials Biomedical Research Institute Korea Institute of Science and Technology (KIST) 5, Hwarang-ro 14-gil Seongbuk-gu Seoul 02792 Korea
| | - Kyun Kyu Kim
- Department of Chemical Engineering Stanford University Stanford CA 94305 USA
| | - Kyungwoo Lee
- Center for Biomaterials Biomedical Research Institute Korea Institute of Science and Technology (KIST) 5, Hwarang-ro 14-gil Seongbuk-gu Seoul 02792 Korea
| | - Wonryung Lee
- Center for Biomaterials Biomedical Research Institute Korea Institute of Science and Technology (KIST) 5, Hwarang-ro 14-gil Seongbuk-gu Seoul 02792 Korea
| | - Hojeong Jeon
- Center for Biomaterials Biomedical Research Institute Korea Institute of Science and Technology (KIST) 5, Hwarang-ro 14-gil Seongbuk-gu Seoul 02792 Korea
- KU-KIST Graduate School of Converging Science and Technology Korea University 145, Anam-ro Seongbuk-gu Seoul 02841 Korea
| | - Seung Hwan Ko
- Applied Nano and Thermal Science Lab Department of Mechanical Engineering Seoul National University 1 Gwanak-ro Gwanak-gu Seoul 151-742 Korea
- Institute of Advanced Machines and Design/Institute of Engineering Research Seoul National University Seoul 08826 Korea
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14
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Chapman CAR, Cuttaz EA, Tahirbegi B, Novikov A, Petkos K, Koutsoftidis S, Drakakis EM, Goding JA, Green RA. Flexible Networks of Patterned Conducting Polymer Nanowires for Fully Polymeric Bioelectronics. ADVANCED NANOBIOMED RESEARCH 2021. [DOI: 10.1002/anbr.202100102] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Affiliation(s)
| | - Estelle A. Cuttaz
- Department of Bioengineering Imperial College London South Kensington London SW7 2AZ UK
| | - Bogachan Tahirbegi
- Department of Bioengineering Imperial College London South Kensington London SW7 2AZ UK
| | - Alexey Novikov
- Department of Bioengineering Imperial College London South Kensington London SW7 2AZ UK
| | - Konstantinos Petkos
- Department of Bioengineering Imperial College London South Kensington London SW7 2AZ UK
- Center for Neurotechnology Imperial College London Prince Consort Road London SW7 2AZ UK
| | - Simos Koutsoftidis
- Department of Bioengineering Imperial College London South Kensington London SW7 2AZ UK
| | - Emmanuel M. Drakakis
- Department of Bioengineering Imperial College London South Kensington London SW7 2AZ UK
- Center for Neurotechnology Imperial College London Prince Consort Road London SW7 2AZ UK
| | - Josef A. Goding
- Department of Bioengineering Imperial College London South Kensington London SW7 2AZ UK
| | - Rylie A. Green
- Department of Bioengineering Imperial College London South Kensington London SW7 2AZ UK
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15
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Shi D, Dhawan V, Cui XT. Bio-integrative design of the neural tissue-device interface. Curr Opin Biotechnol 2021; 72:54-61. [PMID: 34710753 PMCID: PMC8671324 DOI: 10.1016/j.copbio.2021.10.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 09/19/2021] [Accepted: 10/06/2021] [Indexed: 10/20/2022]
Abstract
Neural implants enable bidirectional communications with nervous tissue and have demonstrated tremendous potential in research and clinical applications. To obtain high fidelity and stable information exchange, we need to minimize the undesired host responses and achieve intimate neuron-device interaction. This paper highlights the key bio-integrative strategies aimed at seamless integration through intelligent device designs to minimize the immune responses, as well as incorporate bioactive elements to actively modulate cellular reactions. These approaches span from surface modification and bioactive agent delivery, to biomorphic and biohybrid designs. Many of these strategies have shown effectiveness in functional outcome measures, others are exploratory but with fascinating potentials. The combination of bio-integrative strategies may synergistically promote the next generation of neural interfaces.
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Affiliation(s)
- Delin Shi
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, United States; Center for Neural Basis of Cognition, Pittsburgh, PA, United States
| | - Vaishnavi Dhawan
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, United States; Center for Neural Basis of Cognition, Pittsburgh, PA, United States
| | - Xinyan Tracy Cui
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, United States; Center for Neural Basis of Cognition, Pittsburgh, PA, United States; McGowan Institute for Regenerative Medicine, Pittsburgh, PA, United States.
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16
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Portillo-Lara R, Tahirbegi B, Chapman CAR, Goding JA, Green RA. Mind the gap: State-of-the-art technologies and applications for EEG-based brain-computer interfaces. APL Bioeng 2021; 5:031507. [PMID: 34327294 PMCID: PMC8294859 DOI: 10.1063/5.0047237] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Accepted: 05/19/2021] [Indexed: 11/14/2022] Open
Abstract
Brain-computer interfaces (BCIs) provide bidirectional communication between the brain and output devices that translate user intent into function. Among the different brain imaging techniques used to operate BCIs, electroencephalography (EEG) constitutes the preferred method of choice, owing to its relative low cost, ease of use, high temporal resolution, and noninvasiveness. In recent years, significant progress in wearable technologies and computational intelligence has greatly enhanced the performance and capabilities of EEG-based BCIs (eBCIs) and propelled their migration out of the laboratory and into real-world environments. This rapid translation constitutes a paradigm shift in human-machine interaction that will deeply transform different industries in the near future, including healthcare and wellbeing, entertainment, security, education, and marketing. In this contribution, the state-of-the-art in wearable biosensing is reviewed, focusing on the development of novel electrode interfaces for long term and noninvasive EEG monitoring. Commercially available EEG platforms are surveyed, and a comparative analysis is presented based on the benefits and limitations they provide for eBCI development. Emerging applications in neuroscientific research and future trends related to the widespread implementation of eBCIs for medical and nonmedical uses are discussed. Finally, a commentary on the ethical, social, and legal concerns associated with this increasingly ubiquitous technology is provided, as well as general recommendations to address key issues related to mainstream consumer adoption.
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Affiliation(s)
- Roberto Portillo-Lara
- Department of Bioengineering, Imperial College London, Royal School of Mines, London SW7 2AZ, United Kingdom
| | - Bogachan Tahirbegi
- Department of Bioengineering, Imperial College London, Royal School of Mines, London SW7 2AZ, United Kingdom
| | - Christopher A. R. Chapman
- Department of Bioengineering, Imperial College London, Royal School of Mines, London SW7 2AZ, United Kingdom
| | - Josef A. Goding
- Department of Bioengineering, Imperial College London, Royal School of Mines, London SW7 2AZ, United Kingdom
| | - Rylie A. Green
- Department of Bioengineering, Imperial College London, Royal School of Mines, London SW7 2AZ, United Kingdom
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17
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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: 23] [Impact Index Per Article: 7.7] [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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18
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Gori M, Vadalà G, Giannitelli SM, Denaro V, Di Pino G. Biomedical and Tissue Engineering Strategies to Control Foreign Body Reaction to Invasive Neural Electrodes. Front Bioeng Biotechnol 2021; 9:659033. [PMID: 34113605 PMCID: PMC8185207 DOI: 10.3389/fbioe.2021.659033] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Accepted: 04/27/2021] [Indexed: 12/21/2022] Open
Abstract
Neural-interfaced prostheses aim to restore sensorimotor limb functions in amputees. They rely on bidirectional neural interfaces, which represent the communication bridge between nervous system and neuroprosthetic device by controlling its movements and evoking sensory feedback. Compared to extraneural electrodes (i.e., epineural and perineural implants), intraneural electrodes, implanted within peripheral nerves, have higher selectivity and specificity of neural signal recording and nerve stimulation. However, being implanted in the nerve, their main limitation is represented by the significant inflammatory response that the body mounts around the probe, known as Foreign Body Reaction (FBR), which may hinder their rapid clinical translation. Furthermore, the mechanical mismatch between the consistency of the device and the surrounding neural tissue may contribute to exacerbate the inflammatory state. The FBR is a non-specific reaction of the host immune system to a foreign material. It is characterized by an early inflammatory phase eventually leading to the formation of a fibrotic capsule around intraneural interfaces, which increases the electrical impedance over time and reduces the chronic interface biocompatibility and functionality. Thus, the future in the reduction and control of the FBR relies on innovative biomedical strategies for the fabrication of next-generation neural interfaces, such as the development of more suitable designs of the device with smaller size, appropriate stiffness and novel conductive and biomimetic coatings for improving their long-term stability and performance. Here, we present and critically discuss the latest biomedical approaches from material chemistry and tissue engineering for controlling and mitigating the FBR in chronic neural implants.
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Affiliation(s)
- Manuele Gori
- Laboratory for Regenerative Orthopaedics, Department of Orthopaedic Surgery and Traumatology, Università Campus Bio-Medico di Roma, Rome, Italy
- Institute of Biochemistry and Cell Biology (IBBC) - National Research Council (CNR), Rome, Italy
| | - Gianluca Vadalà
- Laboratory for Regenerative Orthopaedics, Department of Orthopaedic Surgery and Traumatology, Università Campus Bio-Medico di Roma, Rome, Italy
| | - Sara Maria Giannitelli
- Laboratory of Tissue Engineering, Department of Engineering, Università Campus Bio-Medico di Roma, Rome, Italy
| | - Vincenzo Denaro
- Laboratory for Regenerative Orthopaedics, Department of Orthopaedic Surgery and Traumatology, Università Campus Bio-Medico di Roma, Rome, Italy
| | - Giovanni Di Pino
- NeXT: Neurophysiology and Neuroengineering of Human-Technology Interaction Research Unit, Università Campus Bio-Medico di Roma, Rome, Italy
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19
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Cuttaz EA, Chapman CAR, Syed O, Goding JA, Green RA. Stretchable, Fully Polymeric Electrode Arrays for Peripheral Nerve Stimulation. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2021; 8:2004033. [PMID: 33898185 PMCID: PMC8061359 DOI: 10.1002/advs.202004033] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Revised: 01/19/2021] [Indexed: 05/08/2023]
Abstract
There is a critical need to transition research level flexible polymer bioelectronics toward the clinic by demonstrating both reliability in fabrication and stable device performance. Conductive elastomers (CEs) are composites of conductive polymers in elastomeric matrices that provide both flexibility and enhanced electrochemical properties compared to conventional metallic electrodes. This work focuses on the development of nerve cuff devices and the assessment of the device functionality at each development stage, from CE material to fully polymeric electrode arrays. Two device types are fabricated by laser machining of a thick and thin CE sheet variant on an insulative polydimethylsiloxane substrate and lamination into tubing to produce pre-curled cuffs. Device performance and stability following sterilization and mechanical loading are compared to a state-of-the-art stretchable metallic nerve cuff. The CE cuffs are found to be electrically and mechanically stable with improved charge transfer properties compared to the commercial cuff. All devices are applied to an ex vivo whole sciatic nerve and shown to be functional, with the CE cuffs demonstrating superior charge transfer and electrochemical safety in the biological environment.
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Affiliation(s)
- Estelle A. Cuttaz
- Department of BioengineeringImperial CollegeSouth KensingtonLondonSW7 2AZUK
| | | | - Omaer Syed
- Department of BioengineeringImperial CollegeSouth KensingtonLondonSW7 2AZUK
| | - Josef A. Goding
- Department of BioengineeringImperial CollegeSouth KensingtonLondonSW7 2AZUK
| | - Rylie A. Green
- Department of BioengineeringImperial CollegeSouth KensingtonLondonSW7 2AZUK
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20
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Llerena Zambrano B, Renz AF, Ruff T, Lienemann S, Tybrandt K, Vörös J, Lee J. Soft Electronics Based on Stretchable and Conductive Nanocomposites for Biomedical Applications. Adv Healthc Mater 2021; 10:e2001397. [PMID: 33205564 DOI: 10.1002/adhm.202001397] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2020] [Revised: 10/08/2020] [Indexed: 12/15/2022]
Abstract
Research on the field of implantable electronic devices that can be directly applied in the body with various functionalities is increasingly intensifying due to its great potential for various therapeutic applications. While conventional implantable electronics generally include rigid and hard conductive materials, their surrounding biological objects are soft and dynamic. The mechanical mismatch between implanted devices and biological environments induces damages in the body especially for long-term applications. Stretchable electronics with outstanding mechanical compliance with biological objects effectively improve such limitations of existing rigid implantable electronics. In this article, the recent progress of implantable soft electronics based on various conductive nanocomposites is systematically described. In particular, representative fabrication approaches of conductive and stretchable nanocomposites for implantable soft electronics and various in vivo applications of implantable soft electronics are focused on. To conclude, challenges and perspectives of current implantable soft electronics that should be considered for further advances are discussed.
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Affiliation(s)
- Byron Llerena Zambrano
- Laboratory of Biosensors and Bioelectronics ETH Zurich Gloriastrasse 35 Zurich 8092 Switzerland
| | - Aline F. Renz
- Laboratory of Biosensors and Bioelectronics ETH Zurich Gloriastrasse 35 Zurich 8092 Switzerland
| | - Tobias Ruff
- Laboratory of Biosensors and Bioelectronics ETH Zurich Gloriastrasse 35 Zurich 8092 Switzerland
| | - Samuel Lienemann
- Laboratory of Organic Electronics Department of Science and Technology Linköping University Norrköping 601 74 Sweden
| | - Klas Tybrandt
- Laboratory of Organic Electronics Department of Science and Technology Linköping University Norrköping 601 74 Sweden
| | - János Vörös
- Laboratory of Biosensors and Bioelectronics ETH Zurich Gloriastrasse 35 Zurich 8092 Switzerland
| | - Jaehong Lee
- Department of Robotics Engineering Daegu Gyeongbuk Institute of Science and Technology (DGIST) 333 Techno jungan‐dareo Daegu 42988 South Korea
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21
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Preparation of Multiwall Carbon Nanotubes Embedded Electroconductive Multi-Microchannel Scaffolds for Neuron Growth under Electrical Stimulation. BIOMED RESEARCH INTERNATIONAL 2020; 2020:4794982. [PMID: 32337253 PMCID: PMC7153003 DOI: 10.1155/2020/4794982] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Revised: 02/21/2020] [Accepted: 02/22/2020] [Indexed: 12/20/2022]
Abstract
Objectives To prepare the conductive MWCNT (multiwall carbon nanotube)-agarose scaffolds with multi-microchannel for neuron growth under electrical stimulation. Methods The scaffolds were produced by gradient freeze and lyophilization methods. The synthesized materials were characterized by SEM and near-infrared spectroscopy, and their microstructure, swelling-deswelling, conductivity, biocompatibility, and shape memory behavior were measured. A three-dimensional culture model by implanting cells into scaffolds was built, and the behaviors of RSC96 cells on scaffolds under electrical stimulation were evaluated. Results The addition of MWCNT did not affect the pore composition ratio and shape memory of agarose scaffolds, but 0.025% wt MWCNT in scaffolds improved the swelling ratio and water retention at the swelling equilibrium state. Though MWCNTs in high concentration had slight effect on proliferation of RSC96 cells and PC12 cells, there was no difference that the expressions of neurofilament of RSC96 cells on scaffolds with MWCNTs of different concentration. RSC96 cells arranged better along the longitudinal axis of scaffolds and showed better adhesion on both 0.025% MWCNT-agarose scaffolds and 0.05% MWCNT-agarose scaffolds compared to other scaffolds. Conclusions Agarose scaffolds with MWCNTs possessed promising applicable prospect in peripheral nerve defects.
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22
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Zheng XS, Griffith AY, Chang E, Looker MJ, Fisher LE, Clapsaddle B, Cui XT. Evaluation of a conducting elastomeric composite material for intramuscular electrode application. Acta Biomater 2020; 103:81-91. [PMID: 31863910 DOI: 10.1016/j.actbio.2019.12.021] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 11/25/2019] [Accepted: 12/10/2019] [Indexed: 01/14/2023]
Abstract
Electrical stimulation of the muscle has been proven efficacious in preventing atrophy and/or reanimating paralyzed muscles. Intramuscular electrodes made from metals have significantly higher Young's Moduli than the muscle tissues, which has the potential to cause chronic inflammation and decrease device performance. Here, we present an intramuscular electrode made from an elastomeric conducting polymer composite consisting of PEDOT-PEG copolymer, silicone and carbon nanotubes (CNT) with fluorosilicone insulation. The electrode wire has a Young's modulus of 804 (±99) kPa, which better mimics the muscle tissue modulus than conventional stainless steel (SS) electrodes. Additionally, the non-metallic composition enables metal-artifact free CT and MR imaging. These soft wire (SW) electrodes present comparable electrical impedance to SS electrodes of similar geometric surface area, activate muscle at a lower threshold, and maintain stable electrical properties in vivo up to 4 weeks. Histologically, the SW electrodes elicited significantly less fibrotic encapsulation and less IBA-1 positive macrophage accumulation than the SS electrodes at one and three months. Further phenotyping the macrophages with the iNOS (pro-inflammatory) and ARG-1 (pro-healing) markers revealed significantly less presence of pro-inflammatory macrophage around SW implants at one month. By three months, there was a significant increase in pro-healing macrophages (ARG-1) around the SW implants but not around the SS implants. Furthermore, a larger number of AchR clusters closer to SW implants were found at both time points compared to SS implants. These results suggest that a softer implant encourages a more intimate and healthier electrode-tissue interface. STATEMENT OF SIGNIFICANCE: Intramuscular electrodes made from metals have significantly higher Young's Moduli than the muscle tissues, which has the potential to cause chronic inflammation and decrease device performance. Here, we present an intramuscular electrode made from an elastomeric conducting polymer composite consisting of PEDOT-PEG copolymer, silicone and carbon nanotubes with fluorosilicone insulation. This elastomeric composite results in an electrode wire with a Young's modulus mimicking that of the muscle tissue, which elicits significantly less foreign body response compared to stainless steel wires. The lack of metal in this composite also enables metal-artifact free MRI and CT imaging.
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Affiliation(s)
- X Sally Zheng
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA 15213, United States
| | - Azante Y Griffith
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA 15213, United States
| | - Emily Chang
- TDA Research Inc., Wheat Ridge, CO 80033, United States
| | | | - Lee E Fisher
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA 15213, United States; Department of Physical Medicine and Rehabilitation, University of Pittsburgh, Pittsburgh, PA 15213, United States; Center for Neural Basis of Cognition, University of Pittsburgh, Pittsburgh, PA, United States
| | | | - X Tracy Cui
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA 15213, United States; Center for 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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23
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Sung C, Jeon W, Nam KS, Kim Y, Butt H, Park S. Multimaterial and multifunctional neural interfaces: from surface-type and implantable electrodes to fiber-based devices. J Mater Chem B 2020; 8:6624-6666. [DOI: 10.1039/d0tb00872a] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Development of neural interfaces from surface electrodes to fibers with various type, functionality, and materials.
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Affiliation(s)
- Changhoon Sung
- Department of Bio and Brain Engineering
- Korea Advanced Institute of Science and Technology (KAIST)
- Daejeon 34141
- Republic of Korea
| | - Woojin Jeon
- Department of Bio and Brain Engineering
- Korea Advanced Institute of Science and Technology (KAIST)
- Daejeon 34141
- Republic of Korea
| | - Kum Seok Nam
- School of Electrical Engineering
- Korea Advanced Institute of Science and Technology (KAIST)
- Daejeon 34141
- Republic of Korea
| | - Yeji Kim
- Department of Bio and Brain Engineering
- Korea Advanced Institute of Science and Technology (KAIST)
- Daejeon 34141
- Republic of Korea
| | - Haider Butt
- Department of Mechanical Engineering
- Khalifa University
- Abu Dhabi 127788
- United Arab Emirates
| | - Seongjun Park
- Department of Bio and Brain Engineering
- Korea Advanced Institute of Science and Technology (KAIST)
- Daejeon 34141
- Republic of Korea
- KAIST Institute for Health Science and Technology (KIHST)
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24
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Woeppel KM, Zheng XS, Schulte ZM, Rosi NL, Cui XT. Nanoparticle Doped PEDOT for Enhanced Electrode Coatings and Drug Delivery. Adv Healthc Mater 2019; 8:e1900622. [PMID: 31583857 PMCID: PMC6842062 DOI: 10.1002/adhm.201900622] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Revised: 08/30/2019] [Indexed: 12/22/2022]
Abstract
In order to address material limitations of biologically interfacing electrodes, modified silica nanoparticles are utilized as dopants for conducting polymers. Silica precursors are selected to form a thiol modified particle (TNP), following which the particles are oxidized to sulfonate modified nanoparticles (SNPs). The selective inclusion of hexadecyl trimethylammonium bromide allows for synthesis of both porous and nonporous SNPs. Nonporous nanoparticle doped polyethylenedioxythiophene (PEDOT) films possess low interfacial impedance, high charge injection (4.8 mC cm-2 ), and improved stability under stimulation compared to PEDOT/poly(styrenesulfonate). Porous SNP dopants can serve as drug reservoirs and greatly enhance the capability of conducting polymer-based, electrically controlled drug release technology. Using the SNP dopants, drug loading and release is increased up to 16.8 times, in addition to greatly expanding the range of drug candidates to include both cationic and electroactive compounds, all while maintaining their bioactivity. Finally, the PEDOT/SNP composite is capable of precisely modulating neural activity in vivo by timed release of a glutamate receptor antagonist from coated microelectrode sites. Together, this work demonstrates the feasibility and potential of doping conducting polymers with engineered nanoparticles, creating countless options to produce composite materials for enhanced electrical stimulation, neural recording, chemical sensing, and on demand drug delivery.
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Affiliation(s)
- Kevin M. Woeppel
- 3501 Fifth ave, 5065, Pittsburgh, Pa 15213, United States of America
| | - X. Sally Zheng
- 3501 Fifth ave, 5065, Pittsburgh, Pa 15213, United States of America
| | | | - Nathaniel L. Rosi
- 3501 Fifth ave, 5065, Pittsburgh, Pa 15213, United States of America
| | - X. Tracy Cui
- 3501 Fifth ave, 5065, Pittsburgh, Pa 15213, United States of America
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