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Rajnicek AM, Casañ-Pastor N. Wireless control of nerve growth using bipolar electrodes: a new paradigm in electrostimulation. Biomater Sci 2024; 12:2180-2202. [PMID: 38358306 DOI: 10.1039/d3bm01946b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2024]
Abstract
Electrical activity underpins all life, but is most familiar in the nervous system, where long range electrical signalling is essential for function. When this is lost (e.g., traumatic injury) or it becomes inefficient (e.g., demyelination), the use of external fields can compensate for at least some functional deficits. However, its potential to also promote biological repair at the cell level is underplayed despite abundant in vitro evidence for control of neuron growth. This perspective article considers specifically the emerging possibility of achieving cell growth through the interaction of external electric fields using conducting materials as unwired bipolar electrodes, and without intending stimulation of neuron electrical activity to be the primary consequence. The use of a wireless method to create electrical interactions represents a paradigm shift and may allow new applications in vivo where physical wiring is not possible. Within that scheme of thought an evaluation of specific materials and their dynamic responses as bipolar unwired electrodes is summarized and correlated with changes in dynamic nerve growth during stimulation, suggesting possible future schemes to achieve neural growth using bipolar unwired electrodes with specific characteristics. This strategy emphasizes how nerve growth can be encouraged at injury sites wirelessly to induce repair, as opposed to implanting devices that may substitute the neural signals.
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Affiliation(s)
- Ann M Rajnicek
- Institute of Medical Sciences, University of Aberdeen, Aberdeen, AB25 2ZD, Scotland, United KIngdom
| | - Nieves Casañ-Pastor
- Institut de Ciència de Materials de Barcelona, CSIC, Campus UAB, 08193 Bellaterra, Barcelona, Spain.
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2
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Kundu A, Patrick E, Currlin S, Madler R, Delgado F, Fahmy A, Verplancke R, Ballini M, Braeken D, de Beeck MO, Maghari N, Otto KJ, Bashirullah R. Using Compound Neural Action Potentials for Functional Validation of a High-Density Intraneural Interface: A Preliminary Study. MICROMACHINES 2024; 15:280. [PMID: 38399008 PMCID: PMC10891740 DOI: 10.3390/mi15020280] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2024] [Revised: 02/14/2024] [Accepted: 02/15/2024] [Indexed: 02/25/2024]
Abstract
Compound nerve action potentials (CNAPs) were used as a metric to assess the stimulation performance of a novel high-density, transverse, intrafascicular electrode in rat models. We show characteristic CNAPs recorded from distally implanted cuff electrodes. Evaluation of the CNAPs as a function of stimulus current and calculation of recruitment plots were used to obtain a qualitative approximation of the neural interface's placement and orientation inside the nerve. This method avoids elaborate surgeries required for the implantation of EMG electrodes and thus minimizes surgical complications and may accelerate the healing process of the implanted subject.
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Affiliation(s)
- Aritra Kundu
- Department of Bioengineering, Imperial College London, SW7 2AZ London, UK
- Department of Electrical and Computer Engineering, University of Florida, Gainesville, FL 32611, USA; (E.P.); (N.M.)
| | - Erin Patrick
- Department of Electrical and Computer Engineering, University of Florida, Gainesville, FL 32611, USA; (E.P.); (N.M.)
| | - Seth Currlin
- Department of Biomedical Engineering, University of Florida, Gainesville, FL 32611, USA (K.J.O.)
| | - Ryan Madler
- Department of Electrical and Computer Engineering, University of Florida, Gainesville, FL 32611, USA; (E.P.); (N.M.)
| | - Francisco Delgado
- Department of Biomedical Engineering, University of Florida, Gainesville, FL 32611, USA (K.J.O.)
| | - Ahmed Fahmy
- Department of Electrical and Computer Engineering, University of Florida, Gainesville, FL 32611, USA; (E.P.); (N.M.)
| | - Rik Verplancke
- Centre for Microsystems Technology (CMST), IMEC and Ghent University, 9052 Zwijnaarde, Belgium (M.O.d.B.)
| | | | | | - Maaike Op de Beeck
- Centre for Microsystems Technology (CMST), IMEC and Ghent University, 9052 Zwijnaarde, Belgium (M.O.d.B.)
- IMEC, Kapeldreef 75, 3001 Leuven, Belgium;
| | - Nima Maghari
- Department of Electrical and Computer Engineering, University of Florida, Gainesville, FL 32611, USA; (E.P.); (N.M.)
| | - Kevin J. Otto
- Department of Biomedical Engineering, University of Florida, Gainesville, FL 32611, USA (K.J.O.)
| | - Rizwan Bashirullah
- Department of Electrical and Computer Engineering, University of Florida, Gainesville, FL 32611, USA; (E.P.); (N.M.)
- Galvani Bioelectronics, South San Francisco, CA 94080, USA
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3
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Taghlabi KM, Cruz-Garza JG, Hassan T, Potnis O, Bhenderu LS, Guerrero JR, Whitehead RE, Wu Y, Luan L, Xie C, Robinson JT, Faraji AH. Clinical outcomes of peripheral nerve interfaces for rehabilitation in paralysis and amputation: a literature review. J Neural Eng 2024; 21:011001. [PMID: 38237175 DOI: 10.1088/1741-2552/ad200f] [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: 04/03/2023] [Accepted: 01/18/2024] [Indexed: 02/02/2024]
Abstract
Peripheral nerve interfaces (PNIs) are electrical systems designed to integrate with peripheral nerves in patients, such as following central nervous system (CNS) injuries to augment or replace CNS control and restore function. We review the literature for clinical trials and studies containing clinical outcome measures to explore the utility of human applications of PNIs. We discuss the various types of electrodes currently used for PNI systems and their functionalities and limitations. We discuss important design characteristics of PNI systems, including biocompatibility, resolution and specificity, efficacy, and longevity, to highlight their importance in the current and future development of PNIs. The clinical outcomes of PNI systems are also discussed. Finally, we review relevant PNI clinical trials that were conducted, up to the present date, to restore the sensory and motor function of upper or lower limbs in amputees, spinal cord injury patients, or intact individuals and describe their significant findings. This review highlights the current progress in the field of PNIs and serves as a foundation for future development and application of PNI systems.
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Affiliation(s)
- Khaled M Taghlabi
- Department of Neurological Surgery, Houston Methodist Hospital, Houston, TX 77030, United States of America
- Center for Neural Systems Restoration, Houston Methodist Research Institute, Houston, TX 77030, United States of America
- Clinical Innovations Laboratory, Houston Methodist Research Institute, Houston, TX 77030, United States of America
| | - Jesus G Cruz-Garza
- Department of Neurological Surgery, Houston Methodist Hospital, Houston, TX 77030, United States of America
- Center for Neural Systems Restoration, Houston Methodist Research Institute, Houston, TX 77030, United States of America
- Clinical Innovations Laboratory, Houston Methodist Research Institute, Houston, TX 77030, United States of America
| | - Taimur Hassan
- Department of Neurological Surgery, Houston Methodist Hospital, Houston, TX 77030, United States of America
- Center for Neural Systems Restoration, Houston Methodist Research Institute, Houston, TX 77030, United States of America
- Clinical Innovations Laboratory, Houston Methodist Research Institute, Houston, TX 77030, United States of America
- School of Medicine, Texas A&M University, Bryan, TX 77807, United States of America
| | - Ojas Potnis
- Department of Neurological Surgery, Houston Methodist Hospital, Houston, TX 77030, United States of America
- Center for Neural Systems Restoration, Houston Methodist Research Institute, Houston, TX 77030, United States of America
- Clinical Innovations Laboratory, Houston Methodist Research Institute, Houston, TX 77030, United States of America
- School of Engineering Medicine, Texas A&M University, Houston, TX 77030, United States of America
| | - Lokeshwar S Bhenderu
- Department of Neurological Surgery, Houston Methodist Hospital, Houston, TX 77030, United States of America
- Center for Neural Systems Restoration, Houston Methodist Research Institute, Houston, TX 77030, United States of America
- Clinical Innovations Laboratory, Houston Methodist Research Institute, Houston, TX 77030, United States of America
- School of Medicine, Texas A&M University, Bryan, TX 77807, United States of America
| | - Jaime R Guerrero
- Department of Neurological Surgery, Houston Methodist Hospital, Houston, TX 77030, United States of America
- Center for Neural Systems Restoration, Houston Methodist Research Institute, Houston, TX 77030, United States of America
- Clinical Innovations Laboratory, Houston Methodist Research Institute, Houston, TX 77030, United States of America
| | - Rachael E Whitehead
- Department of Academic Affairs, Houston Methodist Academic Institute, Houston, TX 77030, United States of America
| | - Yu Wu
- Rice Neuroengineering Initiative, Rice University, Houston, TX 77005, United States of America
- Department of Electrical and Computer Engineering, Rice University, Houston, TX 77005, United States of America
| | - Lan Luan
- Rice Neuroengineering Initiative, Rice University, Houston, TX 77005, United States of America
- Department of Electrical and Computer Engineering, Rice University, Houston, TX 77005, United States of America
| | - Chong Xie
- Rice Neuroengineering Initiative, Rice University, Houston, TX 77005, United States of America
- Department of Electrical and Computer Engineering, Rice University, Houston, TX 77005, United States of America
| | - Jacob T Robinson
- Rice Neuroengineering Initiative, Rice University, Houston, TX 77005, United States of America
- Department of Electrical and Computer Engineering, Rice University, Houston, TX 77005, United States of America
| | - Amir H Faraji
- Department of Neurological Surgery, Houston Methodist Hospital, Houston, TX 77030, United States of America
- Center for Neural Systems Restoration, Houston Methodist Research Institute, Houston, TX 77030, United States of America
- Clinical Innovations Laboratory, Houston Methodist Research Institute, Houston, TX 77030, United States of America
- Rice Neuroengineering Initiative, Rice University, Houston, TX 77005, United States of America
- Department of Electrical and Computer Engineering, Rice University, Houston, TX 77005, United States of America
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4
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Alahi MEE, Liu Y, Khademi S, Nag A, Wang H, Wu T, Mukhopadhyay SC. Slippery Epidural ECoG Electrode for High-Performance Neural Recording and Interface. BIOSENSORS 2022; 12:1044. [PMID: 36421162 PMCID: PMC9688081 DOI: 10.3390/bios12111044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Revised: 11/02/2022] [Accepted: 11/16/2022] [Indexed: 06/16/2023]
Abstract
Chronic implantation of an epidural Electrocorticography (ECoG) electrode produces thickening of the dura mater and proliferation of the fibrosis around the interface sites, which is a significant concern for chronic neural ECoG recording applications used to monitor various neurodegenerative diseases. This study describes a new approach to developing a slippery liquid-infused porous surface (SLIPS) on the flexible ECoG electrode for a chronic neural interface with the advantage of increased cell adhesion. In the demonstration, the electrode was fabricated on the polyimide (PI) substrate, and platinum (Pt)-gray was used for creating the porous nanocone structure for infusing the silicone oil. The combination of nanocone and the infused slippery oil layer created the SLIPS coating, which has a low impedance (4.68 kΩ) level favourable for neural recording applications. The electrochemical impedance spectroscopy and equivalent circuit modelling also showed the effect of the coating on the recording site. The cytotoxicity study demonstrated that the coating does not have any cytotoxic potentiality; hence, it is biocompatible for human implantation. The in vivo (acute recording) neural recording on the rat model also confirmed that the noise level could be reduced significantly (nearly 50%) and is helpful for chronic ECoG recording for more extended neural signal recording applications.
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Affiliation(s)
- Md Eshrat E. Alahi
- The Institute of Biomedical and Health Engineering, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
| | - Yonghong Liu
- The Institute of Biomedical and Health Engineering, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
| | - Sara Khademi
- The Institute of Biomedical and Health Engineering, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
- Institute of Polymeric Materials and Faculty of Polymer Engineering, Sahand University of Technology, Tabriz P.O. Box 51335/1996, Iran
| | - Anindya Nag
- Faculty of Electrical and Computer Engineering, Technische Universität Dresden, 01062 Dresden, Germany
- Centre for Tactile Internet with Human-in-the-Loop (CeTI), Technische Universität Dresden, 01069 Dresden, Germany
| | - Hao Wang
- The Institute of Biomedical and Health Engineering, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
| | - Tianzhun Wu
- The Institute of Biomedical and Health Engineering, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
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5
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Wang D, Tan J, Zhu H, Mei Y, Liu X. Biomedical Implants with Charge-Transfer Monitoring and Regulating Abilities. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2021; 8:e2004393. [PMID: 34166584 PMCID: PMC8373130 DOI: 10.1002/advs.202004393] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 05/12/2021] [Indexed: 05/06/2023]
Abstract
Transmembrane charge (ion/electron) transfer is essential for maintaining cellular homeostasis and is involved in many biological processes, from protein synthesis to embryonic development in organisms. Designing implant devices that can detect or regulate cellular transmembrane charge transfer is expected to sense and modulate the behaviors of host cells and tissues. Thus, charge transfer can be regarded as a bridge connecting living systems and human-made implantable devices. This review describes the mode and mechanism of charge transfer between organisms and nonliving materials, and summarizes the strategies to endow implants with charge-transfer regulating or monitoring abilities. Furthermore, three major charge-transfer controlling systems, including wired, self-activated, and stimuli-responsive biomedical implants, as well as the design principles and pivotal materials are systematically elaborated. The clinical challenges and the prospects for future development of these implant devices are also discussed.
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Affiliation(s)
- Donghui Wang
- State Key Laboratory of High Performance Ceramics and Superfine MicrostructureShanghai Institutes of CeramicsChinese Academy of SciencesShanghai200050China
- School of Materials Science and EngineeringHebei University of TechnologyTianjin300130China
| | - Ji Tan
- State Key Laboratory of High Performance Ceramics and Superfine MicrostructureShanghai Institutes of CeramicsChinese Academy of SciencesShanghai200050China
| | - Hongqin Zhu
- State Key Laboratory of High Performance Ceramics and Superfine MicrostructureShanghai Institutes of CeramicsChinese Academy of SciencesShanghai200050China
- Department of Materials ScienceFudan UniversityShanghai200433China
| | - Yongfeng Mei
- Department of Materials ScienceFudan UniversityShanghai200433China
| | - Xuanyong Liu
- State Key Laboratory of High Performance Ceramics and Superfine MicrostructureShanghai Institutes of CeramicsChinese Academy of SciencesShanghai200050China
- School of Chemistry and Materials ScienceHangzhou Institute for Advanced StudyUniversity of Chinese Academy of SciencesHangzhou310024China
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6
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Shoffstall AJ, Capadona JR. Bioelectronic Neural Implants. Biomater Sci 2020. [DOI: 10.1016/b978-0-12-816137-1.00073-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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7
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Trevathan JK, Baumgart IW, Nicolai EN, Gosink BA, Asp AJ, Settell ML, Polaconda SR, Malerick KD, Brodnick SK, Zeng W, Knudsen BE, McConico AL, Sanger Z, Lee JH, Aho JM, Suminski AJ, Ross EK, Lujan JL, Weber DJ, Williams JC, Franke M, Ludwig KA, Shoffstall AJ. An Injectable Neural Stimulation Electrode Made from an In-Body Curing Polymer/Metal Composite. Adv Healthc Mater 2019; 8:e1900892. [PMID: 31697052 PMCID: PMC10425988 DOI: 10.1002/adhm.201900892] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Revised: 09/20/2019] [Indexed: 12/15/2022]
Abstract
Implanted neural stimulation and recording devices hold vast potential to treat a variety of neurological conditions, but the invasiveness, complexity, and cost of the implantation procedure greatly reduce access to an otherwise promising therapeutic approach. To address this need, a novel electrode that begins as an uncured, flowable prepolymer that can be injected around a neuroanatomical target to minimize surgical manipulation is developed. Referred to as the Injectrode, the electrode conforms to target structures forming an electrically conductive interface which is orders of magnitude less stiff than conventional neuromodulation electrodes. To validate the Injectrode, detailed electrochemical and microscopy characterization of its material properties is performed and the feasibility of using it to stimulate the nervous system electrically in rats and swine is validated. The silicone-metal-particle composite performs very similarly to pure wire of the same metal (silver) in all measures, including exhibiting a favorable cathodic charge storage capacity (CSCC ) and charge injection limits compared to the clinical LivaNova stimulation electrode and silver wire electrodes. By virtue of its simplicity, the Injectrode has the potential to be less invasive, more robust, and more cost-effective than traditional electrode designs, which could increase the adoption of neuromodulation therapies for existing and new indications.
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Affiliation(s)
- James K Trevathan
- Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, 53706, USA
- Mayo Clinic Graduate School of Biomedical Sciences, Mayo Clinic, Rochester, MN, 55902, USA
| | - Ian W Baumgart
- Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Evan N Nicolai
- Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, 53706, USA
- Mayo Clinic Graduate School of Biomedical Sciences, Mayo Clinic, Rochester, MN, 55902, USA
| | - Brian A Gosink
- Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, 53706, USA
- Department of Neurosurgery, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Anders J Asp
- Mayo Clinic Graduate School of Biomedical Sciences, Mayo Clinic, Rochester, MN, 55902, USA
| | - Megan L Settell
- Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, 53706, USA
- Mayo Clinic Graduate School of Biomedical Sciences, Mayo Clinic, Rochester, MN, 55902, USA
| | - Shyam R Polaconda
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Kevin D Malerick
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Sarah K Brodnick
- Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Weifeng Zeng
- Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Bruce E Knudsen
- Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, 53706, USA
- Department of Neurologic Surgery, Mayo Clinic, Rochester, MN, 55902, USA
| | - Andrea L McConico
- Department of Neurologic Surgery, Mayo Clinic, Rochester, MN, 55902, USA
| | - Zachary Sanger
- Department of Neurologic Surgery, Mayo Clinic, Rochester, MN, 55902, USA
| | - Jannifer H Lee
- Mayo Clinic Graduate School of Biomedical Sciences, Mayo Clinic, Rochester, MN, 55902, USA
| | - Johnathon M Aho
- Division of General Thoracic Surgery, Mayo Clinic, Rochester, MN, 55902, USA
- Physiology and Biomedical Engineering, Mayo Clinic, Rochester, MN, 55902, USA
| | - Aaron J Suminski
- Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Erika K Ross
- Department of Neurologic Surgery, Mayo Clinic, Rochester, MN, 55902, USA
| | - Jose L Lujan
- Mayo Clinic Graduate School of Biomedical Sciences, Mayo Clinic, Rochester, MN, 55902, USA
- Department of Neurologic Surgery, Mayo Clinic, Rochester, MN, 55902, USA
- Physiology and Biomedical Engineering, Mayo Clinic, Rochester, MN, 55902, USA
| | - Douglas J Weber
- Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, 53706, USA
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, 15260, USA
| | - Justin C Williams
- Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | | | - Kip A Ludwig
- Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, 53706, USA
- Department of Neurosurgery, University of Wisconsin-Madison, Madison, WI, 53706, USA
- Department of Neurologic Surgery, Mayo Clinic, Rochester, MN, 55902, USA
- Neuronoff Inc., Valencia, CA, 91354, USA
| | - Andrew J Shoffstall
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, 44106, USA
- Neuronoff Inc., Valencia, CA, 91354, USA
- Advanced Platform Technologies Center, Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland, OH, 44106, USA
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8
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A review for the peripheral nerve interface designer. J Neurosci Methods 2019; 332:108523. [PMID: 31743684 DOI: 10.1016/j.jneumeth.2019.108523] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Revised: 11/14/2019] [Accepted: 11/15/2019] [Indexed: 12/11/2022]
Abstract
Informational density and relative accessibility of the peripheral nervous system make it an attractive site for therapeutic intervention. Electrode-based electrophysiological interfaces with peripheral nerves have been under development since the 1960s and, for several applications, have seen widespread clinical implementation. However, many applications require a combination of neural target resolution and stability which has thus far eluded existing peripheral nerve interfaces (PNIs). With the goal of aiding PNI designers in development of devices that meet the demands of next-generation applications, this review seeks to collect and present practical considerations and best practices which emerge from the literature, including both lessons learned during early PNI development and recent ideas. Fundamental and practical principles guiding PNI design are reviewed, followed by an updated and critical account of existing PNI designs and strategies. Finally, a brief survey of in vitro and in vivo PNI characterization methods is presented.
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Martins NRB, Angelica A, Chakravarthy K, Svidinenko Y, Boehm FJ, Opris I, Lebedev MA, Swan M, Garan SA, Rosenfeld JV, Hogg T, Freitas RA. Human Brain/Cloud Interface. Front Neurosci 2019; 13:112. [PMID: 30983948 PMCID: PMC6450227 DOI: 10.3389/fnins.2019.00112] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Accepted: 01/30/2019] [Indexed: 12/25/2022] Open
Abstract
The Internet comprises a decentralized global system that serves humanity's collective effort to generate, process, and store data, most of which is handled by the rapidly expanding cloud. A stable, secure, real-time system may allow for interfacing the cloud with the human brain. One promising strategy for enabling such a system, denoted here as a "human brain/cloud interface" ("B/CI"), would be based on technologies referred to here as "neuralnanorobotics." Future neuralnanorobotics technologies are anticipated to facilitate accurate diagnoses and eventual cures for the ∼400 conditions that affect the human brain. Neuralnanorobotics may also enable a B/CI with controlled connectivity between neural activity and external data storage and processing, via the direct monitoring of the brain's ∼86 × 109 neurons and ∼2 × 1014 synapses. Subsequent to navigating the human vasculature, three species of neuralnanorobots (endoneurobots, gliabots, and synaptobots) could traverse the blood-brain barrier (BBB), enter the brain parenchyma, ingress into individual human brain cells, and autoposition themselves at the axon initial segments of neurons (endoneurobots), within glial cells (gliabots), and in intimate proximity to synapses (synaptobots). They would then wirelessly transmit up to ∼6 × 1016 bits per second of synaptically processed and encoded human-brain electrical information via auxiliary nanorobotic fiber optics (30 cm3) with the capacity to handle up to 1018 bits/sec and provide rapid data transfer to a cloud based supercomputer for real-time brain-state monitoring and data extraction. A neuralnanorobotically enabled human B/CI might serve as a personalized conduit, allowing persons to obtain direct, instantaneous access to virtually any facet of cumulative human knowledge. Other anticipated applications include myriad opportunities to improve education, intelligence, entertainment, traveling, and other interactive experiences. A specialized application might be the capacity to engage in fully immersive experiential/sensory experiences, including what is referred to here as "transparent shadowing" (TS). Through TS, individuals might experience episodic segments of the lives of other willing participants (locally or remote) to, hopefully, encourage and inspire improved understanding and tolerance among all members of the human family.
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Affiliation(s)
- Nuno R. B. Martins
- Lawrence Berkeley National Laboratory, Berkeley, CA, United States
- Center for Research and Education on Aging (CREA), University of California, Berkeley and LBNL, Berkeley, CA, United States
| | | | - Krishnan Chakravarthy
- UC San Diego Health Science, San Diego, CA, United States
- VA San Diego Healthcare System, San Diego, CA, United States
| | | | | | - Ioan Opris
- Miami Project to Cure Paralysis, University of Miami, Miami, FL, United States
- Department of Biomedical Engineering, University of Miami, Coral Gables, FL, United States
| | - Mikhail A. Lebedev
- Center for Neuroengineering, Duke University, Durham, NC, United States
- Center for Bioelectric Interfaces of the Institute for Cognitive Neuroscience of the National Research University Higher School of Economics, Moscow, Russia
- Department of Information and Internet Technologies of Digital Health Institute, I.M. Sechenov First Moscow State Medical University, Moscow, Russia
| | - Melanie Swan
- Department of Philosophy, Purdue University, West Lafayette, IN, United States
| | - Steven A. Garan
- Lawrence Berkeley National Laboratory, Berkeley, CA, United States
- Center for Research and Education on Aging (CREA), University of California, Berkeley and LBNL, Berkeley, CA, United States
| | - Jeffrey V. Rosenfeld
- Monash Institute of Medical Engineering, Monash University, Clayton, VIC, Australia
- Department of Neurosurgery, Alfred Hospital, Melbourne, VIC, Australia
- Department of Surgery, Monash University, Clayton, VIC, Australia
- Department of Surgery, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
| | - Tad Hogg
- Institute for Molecular Manufacturing, Palo Alto, CA, United States
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10
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Fernandez E. Development of visual Neuroprostheses: trends and challenges. Bioelectron Med 2018; 4:12. [PMID: 32232088 PMCID: PMC7098238 DOI: 10.1186/s42234-018-0013-8] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2018] [Accepted: 07/27/2018] [Indexed: 02/06/2023] Open
Abstract
Visual prostheses are implantable medical devices that are able to provide some degree of vision to individuals who are blind. This research field is a challenging subject in both ophthalmology and basic science that has progressed to a point where there are already several commercially available devices. However, at present, these devices are only able to restore a very limited vision, with relatively low spatial resolution. Furthermore, there are still many other open scientific and technical challenges that need to be solved to achieve the therapeutic benefits envisioned by these new technologies. This paper provides a brief overview of significant developments in this field and introduces some of the technical and biological challenges that still need to be overcome to optimize their therapeutic success, including long-term viability and biocompatibility of stimulating electrodes, the selection of appropriate patients for each artificial vision approach, a better understanding of brain plasticity and the development of rehabilitative strategies specifically tailored for each patient.
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Affiliation(s)
- Eduardo Fernandez
- Institute of Bioengineering, University Miguel Hernández and CIBER-BBN, Avda de la Universidad, s/n, 03202 Alicante, Elche Spain.,2John A. Moran Eye Center, University of Utah, Salt Lake City, USA
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11
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Microbial nanowires - Electron transport and the role of synthetic analogues. Acta Biomater 2018; 69:1-30. [PMID: 29357319 DOI: 10.1016/j.actbio.2018.01.007] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Revised: 01/07/2018] [Accepted: 01/09/2018] [Indexed: 02/07/2023]
Abstract
Electron transfer is central to cellular life, from photosynthesis to respiration. In the case of anaerobic respiration, some microbes have extracellular appendages that can be utilised to transport electrons over great distances. Two model organisms heavily studied in this arena are Shewanella oneidensis and Geobacter sulfurreducens. There is some debate over how, in particular, the Geobacter sulfurreducens nanowires (formed from pilin nanofilaments) are capable of achieving the impressive feats of natural conductivity that they display. In this article, we outline the mechanisms of electron transfer through delocalised electron transport, quantum tunnelling, and hopping as they pertain to biomaterials. These are described along with existing examples of the different types of conductivity observed in natural systems such as DNA and proteins in order to provide context for understanding the complexities involved in studying the electron transport properties of these unique nanowires. We then introduce some synthetic analogues, made using peptides, which may assist in resolving this debate. Microbial nanowires and the synthetic analogues thereof are of particular interest, not just for biogeochemistry, but also for the exciting potential bioelectronic and clinical applications as covered in the final section of the review. STATEMENT OF SIGNIFICANCE Some microbes have extracellular appendages that transport electrons over vast distances in order to respire, such as the dissimilatory metal-reducing bacteria Geobacter sulfurreducens. There is significant debate over how G. sulfurreducens nanowires are capable of achieving the impressive feats of natural conductivity that they display: This mechanism is a fundamental scientific challenge, with important environmental and technological implications. Through outlining the techniques and outcomes of investigations into the mechanisms of such protein-based nanofibrils, we provide a platform for the general study of the electronic properties of biomaterials. The implications are broad-reaching, with fundamental investigations into electron transfer processes in natural and biomimetic materials underway. From these studies, applications in the medical, energy, and IT industries can be developed utilising bioelectronics.
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Sanjuan-Alberte P, Alexander MR, Hague RJM, Rawson FJ. Electrochemically stimulating developments in bioelectronic medicine. Bioelectron Med 2018; 4:1. [PMID: 32232077 PMCID: PMC7098225 DOI: 10.1186/s42234-018-0001-z] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Accepted: 02/13/2018] [Indexed: 12/22/2022] Open
Abstract
Cellular homeostasis is in part controlled by biological generated electrical activity. By interfacing biology with electronic devices this electrical activity can be modulated to actuate cellular behaviour. There are current limitations in merging electronics with biology sufficiently well to target and sense specific electrically active components of cells. By addressing this limitation, researchers give rise to new capabilities for facilitating the two-way transduction signalling mechanisms between the electronic and cellular components. This is required to allow significant advancement of bioelectronic technology which offers new ways of treating and diagnosing diseases. Most of the progress that has been achieved to date in developing bioelectronic therapeutics stimulate neural communication, which ultimately orchestrates organ function back to a healthy state. Some devices used in therapeutics include cochlear and retinal implants and vagus nerve stimulators. However, all cells can be impacted by electrical inputs which gives rise to the opportunity to broaden the use of bioelectronic medicine for treating disease. Electronic actuation of non-excitable cells has been shown to lead to ‘programmed’ cell behaviour via application of electronic input which alter key biological processes. A neglected form of cellular electrical communication which has not yet been considered when developing bioelectronic therapeutics is faradaic currents. These are generated during redox reactions. A precedent of electrochemical technology being used to modulate these reactions, thereby controlling cell behaviour, has already been set. In this mini review we highlight the current state of the art of electronic routes to modulating cell behaviour and identify new ways in which electrochemistry could be used to contribute to the new field of bioelectronic medicine.
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Affiliation(s)
- Paola Sanjuan-Alberte
- 1Regenerative Medicine and Cellular Therapies, School of Pharmacy, University of Nottingham, Nottingham, NG7 2QL UK.,2Centre for Additive Manufacturing, School of Engineering, University of Nottingham, Nottingham, NG7 2QL UK
| | - Morgan R Alexander
- 3Advanced Materials and Healthcare Technologies, School of Pharmacy, University of Nottingham, Nottingham, NG7 2QL UK
| | - Richard J M Hague
- 2Centre for Additive Manufacturing, School of Engineering, University of Nottingham, Nottingham, NG7 2QL UK
| | - Frankie J Rawson
- 1Regenerative Medicine and Cellular Therapies, School of Pharmacy, University of Nottingham, Nottingham, NG7 2QL UK
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Dubey A, Jangir H, Pandey M, Dubey MM, Verma S, Roy M, Singh SK, Philip D, Sarkar S, Das M. An eco-friendly, low-power charge storage device from bio-tolerable nano cerium oxide electrodes for bioelectrical and biomedical applications. Biomed Phys Eng Express 2018. [DOI: 10.1088/2057-1976/aaa282] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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14
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15
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Affiliation(s)
- Eduardo Fernández
- Bioengineering Institute; Miguel Hernández University of Elche and CIBER BBN; Elche 03202 Spain
| | - Pablo Botella
- Instituto de Tecnología Química; Universitat Politècnica de València-Consejo Superior de Investigaciones Científicas; Valencia 46022 Spain
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Karnati C, Aguilar R, Arrowood C, Ross J, Rajaraman S. Micromachining on and of Transparent Polymers for Patterning Electrodes and Growing Electrically Active Cells for Biosensor Applications. MICROMACHINES 2017; 8:E250. [PMID: 30400441 PMCID: PMC6190309 DOI: 10.3390/mi8080250] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/24/2017] [Revised: 07/28/2017] [Accepted: 08/02/2017] [Indexed: 11/17/2022]
Abstract
We report on microfabrication and assembly process development on transparent, biocompatible polymers for patterning electrodes and growing electrically active cells for in vitro cell-based biosensor applications. Such biosensors are typically fabricated on silicon or glass wafers with traditional microelectronic processes that can be cost-prohibitive without imparting necessary biological traits on the devices, such as transparency and compatibility for the measurement of electrical activity of electrogenic cells and other biological functions. We have developed and optimized several methods that utilize traditional micromachining and non-traditional approaches such as printed circuit board (PCB) processing for fabrication of electrodes and growing cells on the transparent polymers polyethylene naphthalate (PEN) and polyethylene terephthalate (PET). PEN-based biosensors are fabricated utilizing lithography, metal lift-off, electroplating, wire bonding, inkjet printing, conformal polymer deposition and laser micromachining, while PET-based biosensors are fabricated utilizing post-processing technologies on modified PCBs. The PEN-based biosensors demonstrate 85⁻100% yield of microelectrodes, and 1-kHz impedance of 59.6 kOhms in a manner comparable to other traditional approaches, with excellent biofunctionality established with an ATP assay. Additional process characterization of the microelectrodes depicts expected metal integrity and trace widths and thicknesses. PET-based biosensors are optimized for a membrane bow of 6.9 to 15.75 µm and 92% electrode yield on a large area. Additional qualitative optical assay for biomaterial recognition with transmitted light microscopy and growth of rat cortical cells for 7 days in vitro (DIV) targeted at biological functionalities such as electrophysiology measurements are demonstrated in this paper.
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Affiliation(s)
| | | | | | - James Ross
- Axion BioSystems Inc., Atlanta, GA 30309, USA.
| | - Swaminathan Rajaraman
- NanoScience Technology Center and Bridging the Innovation Development Gap (BRIDG), Departments of Material Science and Engineering and Electrical and Computer Engineering, University of Central Florida, Orlando, FL 32826, USA.
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Heo DN, Kim HJ, Lee YJ, Heo M, Lee SJ, Lee D, Do SH, Lee SH, Kwon IK. Flexible and Highly Biocompatible Nanofiber-Based Electrodes for Neural Surface Interfacing. ACS NANO 2017; 11:2961-2971. [PMID: 28196320 DOI: 10.1021/acsnano.6b08390] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Polyimide (PI)-based electrodes have been widely used as flexible biosensors in implantable device applications for recording biological signals. However, the long-term quality of neural signals obtained from PI-based nerve electrodes tends to decrease due to nerve damage by neural tissue compression, mechanical mismatch, and insufficient fluid exchange between the neural tissue and electrodes. Here, we resolve these problems with a developed PI nanofiber (NF)-based nerve electrode for stable neural signal recording, which can be fabricated via electrospinning and inkjet printing. We demonstrate an NF-based nerve electrode that can be simply fabricated and easily applied due to its high permeability, flexibility, and biocompatibility. Furthermore, the electrode can record stable neural signals for extended periods of time, resulting in decreased mechanical mismatch, neural compression, and contact area. NF-based electrodes with highly flexible and body-fluid-permeable properties could enable future neural interfacing applications.
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Affiliation(s)
- Dong Nyoung Heo
- Department of Mechanical and Aerospace Engineering, The George Washington University , Washington, DC 20052, United States
- Department of Dental Materials, School of Dentistry, Kyung Hee University , Seoul 02447, Republic of Korea
| | - Han-Jun Kim
- Department of Clinical Pathology, College of Veterinary Medicine, Konkuk University , Seoul 05029, Republic of Korea
| | - Yi Jae Lee
- Center for BioMicroSystems, Korea Institute of Science and Technology , Seoul 02455, Republic of Korea
| | - Min Heo
- Department of Dental Materials, School of Dentistry, Kyung Hee University , Seoul 02447, Republic of Korea
| | - Sang Jin Lee
- Department of Dental Materials, School of Dentistry, Kyung Hee University , Seoul 02447, Republic of Korea
| | - Donghyun Lee
- Department of Dental Materials, School of Dentistry, Kyung Hee University , Seoul 02447, Republic of Korea
| | - Sun Hee Do
- Department of Clinical Pathology, College of Veterinary Medicine, Konkuk University , Seoul 05029, Republic of Korea
| | - Soo Hyun Lee
- Center for BioMicroSystems, Korea Institute of Science and Technology , Seoul 02455, Republic of Korea
| | - Il Keun Kwon
- Department of Dental Materials, School of Dentistry, Kyung Hee University , Seoul 02447, Republic of Korea
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Multifunctional hydrogel coatings on the surface of neural cuff electrode for improving electrode-nerve tissue interfaces. Acta Biomater 2016; 39:25-33. [PMID: 27163406 DOI: 10.1016/j.actbio.2016.05.009] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Revised: 03/18/2016] [Accepted: 05/03/2016] [Indexed: 01/12/2023]
Abstract
UNLABELLED Recently, implantable neural electrodes have been developed for recording and stimulation of the nervous system. However, when the electrode is implanted onto the nerve trunk, the rigid polyimide has a risk of damaging the nerve and can also cause inflammation due to a mechanical mismatch between the stiff polyimide and the soft biological tissue. These processes can interrupt the transmission of nerve signaling. In this paper, we have developed a nerve electrode coated with PEG hydrogel that contains poly(lactic-co-glycolic) acid (PLGA) microspheres (MS) loaded with anti-inflammatory cyclosporin A (CsA). Micro-wells were introduced onto the electrode in order to increase their surface area. This allows for loading a high-dose of the drug. Additionally, chemically treating the surface with aminopropylmethacrylamide can improve the adhesive interface between the electrode and the hydrogel. The surface of the micro-well cuff electrode (MCE) coated with polyethylene glycol (PEG) hydrogel and drug loaded PLGA microspheres (MS) were characterized by SEM and optical microscopy. Additionally, the conductive polymers, poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT/PSS), were formed on the hydrogel layer for improving the nerve signal quality, and then characterized for their electrochemical properties. The loading efficiencies and release profiles were investigated by High Performance Liquid Chromatography (HPLC). The drug loaded electrode resulted in a sustained release of CsA. Moreover, the surface coated electrode with PEG hydrogel and CsA loaded MP showed a significantly decreased fibrous tissue deposition and increased axonal density in animal tests. We expect that the developed nerve electrode will minimize the tissue damage during regeneration of the nervous system. STATEMENT OF SIGNIFICANCE The nerve electrodes are used for interfacing with the central nervous system (CNS) or with the peripheral nervous system (PNS). The interface electrodes should facilitate a closed interconnection with the nerve tissue and provide for selective stimulation and recording from multiple, independent, neurons of the neural system. In this case, an extraneural electrodes such as cuff and perineural electrodes are widely investigated because they can completely cover the nerve trunk and provide for a wide interface area. In this study, we have designed and prepared a functionalized nerve cuff electrode coated with PEG hydrogel containing Poly lactic-co-glycol acid (PLGA) microspheres (MS) loaded with cyclosporine A (CsA). To our knowledge, our findings suggest that surface coating a soft-hydrogel along with an anti-inflammatory drug loaded MS can be a useful strategy for improving the long-term biocompatibility of electrodes.
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Etemadi L, Mohammed M, Thorbergsson PT, Ekstrand J, Friberg A, Granmo M, Pettersson LME, Schouenborg J. Embedded Ultrathin Cluster Electrodes for Long-Term Recordings in Deep Brain Centers. PLoS One 2016; 11:e0155109. [PMID: 27159159 PMCID: PMC4861347 DOI: 10.1371/journal.pone.0155109] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2016] [Accepted: 04/25/2016] [Indexed: 01/03/2023] Open
Abstract
Neural interfaces which allow long-term recordings in deep brain structures in awake freely moving animals have the potential of becoming highly valuable tools in neuroscience. However, the recording quality usually deteriorates over time, probably at least partly due to tissue reactions caused by injuries during implantation, and subsequently micro-forces due to a lack of mechanical compliance between the tissue and neural interface. To address this challenge, we developed a gelatin embedded neural interface comprising highly flexible electrodes and evaluated its long term recording properties. Bundles of ultrathin parylene C coated platinum electrodes (N = 29) were embedded in a hard gelatin based matrix shaped like a needle, and coated with Kollicoat™ to retard dissolution of gelatin during the implantation. The implantation parameters were established in an in vitro model of the brain (0.5% agarose). Following a craniotomy in the anesthetized rat, the gelatin embedded electrodes were stereotactically inserted to a pre-target position, and after gelatin dissolution the electrodes were further advanced and spread out in the area of the subthalamic nucleus (STN). The performance of the implanted electrodes was evaluated under anesthesia, during 8 weeks. Apart from an increase in the median-noise level during the first 4 weeks, the electrode impedance and signal-to-noise ratio of single-units remained stable throughout the experiment. Histological postmortem analysis confirmed implantation in the area of STN in most animals. In conclusion, by combining novel biocompatible implantation techniques and ultra-flexible electrodes, long-term neuronal recordings from deep brain structures with no significant deterioration of electrode function were achieved.
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Affiliation(s)
- Leila Etemadi
- Neuronano Research Center, Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - Mohsin Mohammed
- Neuronano Research Center, Department of Experimental Medical Science, Lund University, Lund, Sweden
- * E-mail: (MM); (JS); (LP)
| | - Palmi Thor Thorbergsson
- Neuronano Research Center, Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - Joakim Ekstrand
- Neuronano Research Center, Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - Annika Friberg
- Neuronano Research Center, Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - Marcus Granmo
- Neuronano Research Center, Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - Lina M. E. Pettersson
- Neuronano Research Center, Department of Experimental Medical Science, Lund University, Lund, Sweden
- * E-mail: (MM); (JS); (LP)
| | - Jens Schouenborg
- Neuronano Research Center, Department of Experimental Medical Science, Lund University, Lund, Sweden
- * E-mail: (MM); (JS); (LP)
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Alcaide M, Papaioannou S, Taylor A, Fekete L, Gurevich L, Zachar V, Pennisi CP. Resistance to protein adsorption and adhesion of fibroblasts on nanocrystalline diamond films: the role of topography and boron doping. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2016; 27:90. [PMID: 26975747 DOI: 10.1007/s10856-016-5696-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2015] [Accepted: 02/29/2016] [Indexed: 06/05/2023]
Abstract
Boron-doped nanocrystalline diamond (BNCD) films exhibit outstanding electrochemical properties that make them very attractive for the fabrication of electrodes for novel neural interfaces and prosthetics. In these devices, the physicochemical properties of the electrode materials are critical to ensure an efficient long-term performance. The aim of this study was to investigate the relative contribution of topography and doping to the biological performance of BNCD films. For this purpose, undoped and boron-doped NCD films were deposited on low roughness (LR) and high roughness (HR) substrates, which were studied in vitro by means of protein adsorption and fibroblast growth assays. Our results show that BNCD films significantly reduce the adsorption of serum proteins, mostly on the LR substrates. As compared to fibroblasts cultured on LR BNCD films, cells grown on the HR BNCD films showed significantly reduced adhesion and lower growth rates. The mean length of fibronectin fibrils deposited by the cells was significantly increased in the BNCD coated substrates, mainly in the LR surfaces. Overall, the largest influence on protein adsorption, cell adhesion, proliferation, and fibronectin deposition was due to the underlying sub-micron topography, with little or no influence of boron doping. In perspective, BNCD films displaying surface roughness in the submicron range may be used as a strategy to reduce the fibroblast growth on the surface of neural electrodes.
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Affiliation(s)
- María Alcaide
- Laboratory for Stem Cell Research, Department of Health Science and Technology, Aalborg University, Fredrik Bajers Vej 3B, 9220, Aalborg, Denmark
| | - Stavros Papaioannou
- Laboratory for Stem Cell Research, Department of Health Science and Technology, Aalborg University, Fredrik Bajers Vej 3B, 9220, Aalborg, Denmark
| | - Andrew Taylor
- Institute of Physics, ASCR v.v.i., Prague, Czech Republic
- Nano6 s.r.o., Kladno, Czech Republic
| | | | - Leonid Gurevich
- Department of Physics and Nanotechnology, Aalborg University, Aalborg ∅, Denmark
| | - Vladimir Zachar
- Laboratory for Stem Cell Research, Department of Health Science and Technology, Aalborg University, Fredrik Bajers Vej 3B, 9220, Aalborg, Denmark
| | - Cristian Pablo Pennisi
- Laboratory for Stem Cell Research, Department of Health Science and Technology, Aalborg University, Fredrik Bajers Vej 3B, 9220, Aalborg, Denmark.
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Parlak O, Turner AP. Switchable bioelectronics. Biosens Bioelectron 2016; 76:251-65. [DOI: 10.1016/j.bios.2015.06.023] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2015] [Revised: 06/09/2015] [Accepted: 06/11/2015] [Indexed: 12/26/2022]
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Biosafety assessment of an intra-neural electrode (TIME) following sub-chronic implantation in the median nerve of Göttingen minipigs. Int J Artif Organs 2014; 37:466-76. [PMID: 24980257 DOI: 10.5301/ijao.5000342] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/20/2014] [Indexed: 11/20/2022]
Abstract
Before a novel peripheral nerve interface can be applied in a neural prosthesis for human use, it is important to determine the biocompatibility of the device. The aim of the present study was to assess the biosafety of the recently developed transverse intrafascicular multi-channel electrode (TIME) in a large nerve animal model. Six TIMEs were implanted (33-38 days) into the median nerves of Göttingen minipigs, and nerve specimens were harvested for histological analysis. We analyzed samples from the area of the implant and from control regions. We found an expected layer of fibrosis around the implant and fibroblasts in both the implant and control region, however, we found no significant presence of inflammatory cells or necrosis. Our results indicated that the TIME may be an attractive, biocompatible neural interface for future neuroprosthesis applications in the clinic setting.
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Fattahi P, Yang G, Kim G, Abidian MR. A review of organic and inorganic biomaterials for neural interfaces. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2014; 26:1846-85. [PMID: 24677434 PMCID: PMC4373558 DOI: 10.1002/adma.201304496] [Citation(s) in RCA: 300] [Impact Index Per Article: 30.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2013] [Revised: 10/08/2013] [Indexed: 05/18/2023]
Abstract
Recent advances in nanotechnology have generated wide interest in applying nanomaterials for neural prostheses. An ideal neural interface should create seamless integration into the nervous system and performs reliably for long periods of time. As a result, many nanoscale materials not originally developed for neural interfaces become attractive candidates to detect neural signals and stimulate neurons. In this comprehensive review, an overview of state-of-the-art microelectrode technologies provided fi rst, with focus on the material properties of these microdevices. The advancements in electro active nanomaterials are then reviewed, including conducting polymers, carbon nanotubes, graphene, silicon nanowires, and hybrid organic-inorganic nanomaterials, for neural recording, stimulation, and growth. Finally, technical and scientific challenges are discussed regarding biocompatibility, mechanical mismatch, and electrical properties faced by these nanomaterials for the development of long-lasting functional neural interfaces.
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Affiliation(s)
- Pouria Fattahi
- Biomedical Engineering Department and Chemical Engineering Departments, Pennsylvania State University, University Park, PA, 16802, USA
| | - Guang Yang
- Biomedical Engineering Department, Pennsylvania State University, University Park, PA, 16802, USA
| | - Gloria Kim
- Biomedical Engineering Department, Pennsylvania State University, University Park, PA, 16802, USA
| | - Mohammad Reza Abidian
- Biomedical Engineering Department, Materials Science & Engineering Department, Chemical Engineering Department, Materials Research Institute, Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, PA, 16802, USA
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Yang L, Li Y, Fang Y. Nanodevices for cellular interfaces and electrophysiological recording. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2013; 25:3881-3887. [PMID: 24048974 DOI: 10.1002/adma.201301194] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Advances in nanomaterials and nanotechnologies offer important opportunities for cellular interfaces. This Research News highlights some recent progress on cellular electrophysiology enabled by using nanostructures as active elements of bioelectronic devices. We begin with a brief description of signal transduction mechanism at device-cell interfaces and then explain the challenges of currently available techniques. Next, specific examples with substantial potential in both extracellular and intracellular electrophysiological recording are given to illustrate the remarkable power of nanostructures and their devices. We will conclude with a discussion of some exciting directions that are currently being pursued in flexible, 3D bioelectronics.
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Affiliation(s)
- Long Yang
- CAS Key Laboratory for Biomedical Effects of Nanomaterials & Nanosafety, National Center for Nanoscience and Technology, China, Beijing 100190
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Bioelectrodes. Biomater Sci 2013. [DOI: 10.1016/b978-0-08-087780-8.00082-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Freire MAM, Morya E, Faber J, Santos JR, Guimaraes JS, Lemos NAM, Sameshima K, Pereira A, Ribeiro S, Nicolelis MAL. Comprehensive analysis of tissue preservation and recording quality from chronic multielectrode implants. PLoS One 2011; 6:e27554. [PMID: 22096594 PMCID: PMC3212580 DOI: 10.1371/journal.pone.0027554] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2011] [Accepted: 10/19/2011] [Indexed: 11/18/2022] Open
Abstract
Multielectrodes have been used with great success to simultaneously record the activity of neuronal populations in awake, behaving animals. In particular, there is great promise in the use of this technique to allow the control of neuroprosthetic devices by human patients. However, it is crucial to fully characterize the tissue response to the chronic implants in animal models ahead of the initiation of human clinical trials. Here we evaluated the effects of unilateral multielectrode implants on the motor cortex of rats weekly recorded for 1-6 months using several histological methods to assess metabolic markers, inflammatory response, immediate-early gene (IEG) expression, cytoskeletal integrity and apoptotic profiles. We also investigated the correlations between each of these features and firing rates, to estimate the impact of post-implant time on neuronal recordings. Overall, limited neuronal loss and glial activation were observed on the implanted sites. Reactivity to enzymatic metabolic markers and IEG expression were not significantly different between implanted and non-implanted hemispheres. Multielectrode recordings remained viable for up to 6 months after implantation, and firing rates correlated well to the histochemical and immunohistochemical markers. Altogether, our results indicate that chronic tungsten multielectrode implants do not substantially alter the histological and functional integrity of target sites in the cerebral cortex.
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Affiliation(s)
| | - Edgard Morya
- Clinical Neurophysiology Laboratory of the Associação Alberto Santos Dumont para Apoio a Pesquisa, Sírio Libanês Hospital, São Paulo/SP, Brazil
| | - Jean Faber
- Edmond and Lily Safra International Institute of Neuroscience of Natal, Natal/RN, Brazil
- Foundation Nanosciences and Clinatec/LETI/CEA, Grenoble, France
| | - Jose Ronaldo Santos
- Edmond and Lily Safra International Institute of Neuroscience of Natal, Natal/RN, Brazil
| | - Joanilson S. Guimaraes
- Edmond and Lily Safra International Institute of Neuroscience of Natal, Natal/RN, Brazil
| | - Nelson A. M. Lemos
- Edmond and Lily Safra International Institute of Neuroscience of Natal, Natal/RN, Brazil
| | - Koichi Sameshima
- Clinical Neurophysiology Laboratory of the Associação Alberto Santos Dumont para Apoio a Pesquisa, Sírio Libanês Hospital, São Paulo/SP, Brazil
- Department of Radiology, School of Medicine, University of São Paulo, São Paulo/SP, Brazil
| | - Antonio Pereira
- Brain Institute, Federal University of Rio Grande do Norte, Natal, RN, Brazil
| | - Sidarta Ribeiro
- Brain Institute, Federal University of Rio Grande do Norte, Natal, RN, Brazil
| | - Miguel A. L. Nicolelis
- Edmond and Lily Safra International Institute of Neuroscience of Natal, Natal/RN, Brazil
- Clinical Neurophysiology Laboratory of the Associação Alberto Santos Dumont para Apoio a Pesquisa, Sírio Libanês Hospital, São Paulo/SP, Brazil
- Center for Neuroengineering, Department of Neurobiology, Duke University Medical Center, Durham, North Carolina, United States of America
- Department of Biomedical Engineering, Duke University, Durham, North Carolina, United States of America
- Department of Psychological and Brain Sciences, Duke University, Durham, North Carolina, United States of America
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Flavel BS, Sweetman MJ, Shearer CJ, Shapter JG, Voelcker NH. Micropatterned arrays of porous silicon: toward sensory biointerfaces. ACS APPLIED MATERIALS & INTERFACES 2011; 3:2463-2471. [PMID: 21699143 DOI: 10.1021/am2003526] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
We describe the fabrication of arrays of porous silicon spots by means of photolithography where a positive photoresist serves as a mask during the anodization process. In particular, photoluminescent arrays and porous silicon spots suitable for further chemical modification and the attachment of human cells were created. The produced arrays of porous silicon were chemically modified by means of a thermal hydrosilylation reaction that facilitated immobilization of the fluorescent dye lissamine, and alternatively, the cell adhesion peptide arginine-glycine-aspartic acid-serine. The latter modification enabled the selective attachment of human lens epithelial cells on the peptide functionalized regions of the patterns. This type of surface patterning, using etched porous silicon arrays functionalized with biological recognition elements, presents a new format of interfacing porous silicon with mammalian cells. Porous silicon arrays with photoluminescent properties produced by this patterning strategy also have potential applications as platforms for in situ monitoring of cell behavior.
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Affiliation(s)
- Benjamin S Flavel
- Centre for Nanoscale Science and Technology, School of Chemical and Physical Sciences, Flinders University, Sturt Road, Bedford Park, Adelaide, South Australia.
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Han N, Rao SS, Johnson J, Parikh KS, Bradley PA, Lannutti JJ, Winter JO. Hydrogel-electrospun fiber mat composite coatings for neural prostheses. FRONTIERS IN NEUROENGINEERING 2011; 4:2. [PMID: 21441993 PMCID: PMC3061411 DOI: 10.3389/fneng.2011.00002] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/16/2010] [Accepted: 02/21/2011] [Indexed: 01/08/2023]
Abstract
Achieving stable, long-term performance of implanted neural prosthetic devices has been challenging because of implantation related neuron loss and a foreign body response that results in encapsulating glial scar formation. To improve neuron–prosthesis integration and form chronic, stable interfaces, we investigated the potential of neurotrophin-eluting hydrogel–electrospun fiber mat (EFM) composite coatings. In particular, poly(ethylene glycol)-poly(ε-caprolactone) (PEGPCL) hydrogel–poly(ε-caprolactone) EFM composites were applied as coatings for multielectrode arrays. Coatings were stable and persisted on electrode surfaces for over 1 month under an agarose gel tissue phantom and over 9 months in a PBS immersion bath. To demonstrate drug release, a neurotrophin, nerve growth factor (NGF), was loaded in the PEGPCL hydrogel layer, and coating cytotoxicity and sustained NGF release were evaluated using a PC12 cell culture model. Quantitative MTT assays showed that these coatings had no significant toxicity toward PC12 cells, and neurite extension at day 7 and 14 confirmed sustained release of NGF at biologically significant concentrations for at least 2 weeks. Our results demonstrate that hydrogel–EFM composite materials can be applied to neural prostheses to improve neuron–electrode proximity and enhance long-term device performance and function.
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Affiliation(s)
- Ning Han
- William G. Lowrie Department of Chemical and Biomolecular Engineering, The Ohio State University Columbus, OH, USA
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Yao L, Pandit A, Yao S, McCaig CD. Electric field-guided neuron migration: a novel approach in neurogenesis. TISSUE ENGINEERING PART B-REVIEWS 2011; 17:143-53. [PMID: 21275787 DOI: 10.1089/ten.teb.2010.0561] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Effective directional neuron migration is crucial in development of the central nervous system and for neurogenesis. Endogenous electrical signals are present in many developing systems and crucial cellular behaviors such as neuronal cell division, cell migration, and cell differentiation are all under the influence of such endogenous electrical cues. Preclinical in vivo studies have used electric fields (EFs) to attempt to enhance regrowth of damaged spinal cord axons with some success. Recent evidence shows that small EFs not only guide axonal growth, but also direct the earlier events of neuronal migration and neuronal cell division. This raises the possibility that applied or endogenous EFs, perhaps in combination, may direct transplanted neural stem cells, or regenerating neurons, to the desired site after brain injury or neuron degeneration. The high complexity of both structure and function of the nervous system, however, poses significant challenges to techniques for applying EFs to promote neurogenesis. The evolution of functional biomaterials and nanotechnology may provide promising solutions for the application of EFs in guiding neuron migration and neurogenesis within the central nervous system.
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Affiliation(s)
- Li Yao
- Network of Excellence for Functional Biomaterials, National Center for Biomedical Engineering Science, National University of Ireland, Galway, Ireland
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Abstract
Fundamental knowledge of motor cognition is an important component in a human factors repertoire, and this chapter serves as a guide to the history, theory, and application of motor cognition research.“From intention to input” captures the scope of this chapter in that cognitive theories of motor control, neural control of movement, and the effects of feedback on movement are all discussed. The chapter progresses from an overview and history of motor cognition theories down to the neural basis for movement, then to an application of these theories via the study of specific actions. From there, rooted in the scientist-practitioner paradigm of human factors, the chapter covers applied considerations for designing control tasks and their associated inputs, taking into account individual differences in motor cognition and control and identifying critical issues in designing for input. General, applied guidelines are provided for use with current and future systems that have a motor cognition component.
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Marin C, Fernández E. Biocompatibility of intracortical microelectrodes: current status and future prospects. FRONTIERS IN NEUROENGINEERING 2010; 3:8. [PMID: 20577634 PMCID: PMC2889721 DOI: 10.3389/fneng.2010.00008] [Citation(s) in RCA: 89] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/29/2009] [Accepted: 05/05/2010] [Indexed: 11/17/2022]
Abstract
Rehabilitation of sensory and/or motor functions in patients with neurological diseases is more and more dealing with artificial electrical stimulation and recording from populations of neurons using biocompatible chronic implants. As more and more patients have benefited from these approaches, the interest in neural interfaces has grown significantly. However an important problem reported with all available microelectrodes to date is long-term viability and biocompatibility. Therefore it is essential to understand the signals that lead to neuroglial activation and create a targeted intervention to control the response, reduce the adverse nature of the reactions and maintain an ideal environment for the brain-electrode interface. We discuss some of the exciting opportunities and challenges that lie in this intersection of neuroscience research, bioengineering, neurology and biomaterials.
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Affiliation(s)
- Cristina Marin
- Institute of Bioengineering, University Miguel Hernández Elche, Spain
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Edwards D, Das M, Molnar P, Hickman JJ. Addition of glutamate to serum-free culture promotes recovery of electrical activity in adult hippocampal neurons in vitro. J Neurosci Methods 2010; 190:155-63. [PMID: 20452373 DOI: 10.1016/j.jneumeth.2010.04.030] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2009] [Revised: 04/29/2010] [Accepted: 04/29/2010] [Indexed: 01/26/2023]
Abstract
A long-term cell culture system utilizing normal adult hippocampal neurons would represent an important tool that could be useful in research on the mature brain, neurological disorders and age-related neurological diseases. Historically, in vitro neuronal systems are derived from embryonic rather than mature brain tissue, a practice predicated upon difficulties in supporting regeneration, functional recovery and long-term survival of adult neurons in vitro. A few studies have shown that neurons derived from the hippocampal tissue of adult rats can survive and regenerate in vitro under serum-free conditions. However, while the adult neurons regenerated morphologically under these conditions, both the electrical activity characteristic of in vivo neurons as well as long-term neuronal survival was not consistently recovered in vitro. In this study, we report on the development of a defined culture system with the ability to support functional recovery and long-term survival of adult rat hippocampal neurons. In this system, the cell-adhesive substrate, N-1 [3-(trimethoxysilyl) propyl]-diethylenetriamine, supported neuronal attachment, regeneration, and long-term survival of adult neurons for more than 80 days in vitro. Additionally, the excitatory neurotransmitter glutamate, applied at 25muM for 1-7 days after morphological neuronal regeneration in vitro, enabled full recovery of neuronal electrical activity. This low concentration of glutamate promoted the recovery of neuronal electrical activity but with minimal excitotoxicity. These improvements allowed electrically active adult neurons to survive in vitro for several months, providing a stable test-bed for the long-term study of regeneration in adult-derived neuronal systems, especially for traumatic brain injury (TBI).
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Affiliation(s)
- Darin Edwards
- NanoScience Technology Center, Orlando, FL 32826, USA
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Tsang WM, Stone AL, Aldworth ZN, Hildebrand JG, Daniel TL, Akinwande AI, Voldman J. Flexible split-ring electrode for insect flight biasing using multisite neural stimulation. IEEE Trans Biomed Eng 2010; 57:1757-64. [PMID: 20176539 DOI: 10.1109/tbme.2010.2041778] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
We describe a flexible multisite microelectrode for insect flight biasing using neural stimulation. The electrode is made of two layers of polyimide (PI) with gold sandwiched in between in a split-ring geometry. The split-ring design in conjunction with the flexibility of the PI allows for a simple insertion process and provides good attachment between the electrode and ventral nerve cord of the insect. Stimulation sites are located at the ends of protruding tips that are circularly distributed inside the split-ring structure. These protruding tips penetrate into the connective tissue surrounding the nerve cord. We have been able to insert the electrode into pupae of the giant sphinx moth Manduca sexta as early as seven days before the adult moth emerges, and we are able to use the multisite electrode to deliver electrical stimuli that evoke multidirectional, graded abdominal motions in both pupae and adult moths. Finally, in loosely tethered flight, we have used stimulation through the flexible microelectrodes to alter the abdominal angle, thus causing the flying moth to deviate to the left or right of its intended path.
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Affiliation(s)
- Wei Mong Tsang
- Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
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Abstract
One of the great challenges facing medicine is the repair of the damaged nervous system. Due to the limited capacity of the central (and to a lesser extent the peripheral) nervous systems to regenerate, damage such as spinal cord injury can often result in permanent paralysis. Researchers are attempting to overcome nerve injury by devising methods of sensing neural activity either in the brain or in the spinal cord or peripheral nervous system. This information can act as a control mechanism for either muscle stimulators (e.g. for restoring limb function) or providing function in some other way (such as controlling a cursor on a computer screen). Ideally, sensing devices are implanted into the body, directly accessing the nervous system. Whilst great advancements have been made in implantable neural stimulators, sensing of neural activity has proven to be a more difficult task. This chapter describes how microengineered probes allow construction of neuron-sized neural interfaces for enhanced recording in vivo.
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Affiliation(s)
- Karla D Bustamante Valles
- Orthopaedic & Rehabilitation Engineering Center, The Medical College of Wisconsin & Marquette University, Milwaukee, WI, USA
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35
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Robust and real-time monitoring of nerve regeneration using implantable flexible microelectrode array. Biosens Bioelectron 2009; 24:1883-7. [DOI: 10.1016/j.bios.2008.09.034] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2008] [Revised: 09/22/2008] [Accepted: 09/23/2008] [Indexed: 11/23/2022]
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Micera S, Navarro X, Carpaneto J, Citi L, Tonet O, Rossini PM, Carrozza MC, Hoffmann KP, Vivó M, Yoshida K, Dario P. On the use of longitudinal intrafascicular peripheral interfaces for the control of cybernetic hand prostheses in amputees. IEEE Trans Neural Syst Rehabil Eng 2009; 16:453-72. [PMID: 18990649 DOI: 10.1109/tnsre.2008.2006207] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Significant strides have been recently made to develop highly sensorized cybernetic prostheses aimed at restoring sensorimotor limb functions to those who have lost them because of a traumatic event (amputation). In these cases, one of the main goals is to create a bidirectional link between the artificial devices (e.g., robotic hands, arms, or legs) and the nervous system. Several human-machine interfaces (HMIs) are currently used to this aim. Among them, interfaces with the peripheral nervous system and in particular longitudinal intrafascicular electrodes can be a promising solution able to improve the current situation. In this paper, the potentials and limits of the use of this interface to control robotic devices are presented. Specific information is provided on: 1) the neurophysiological bases for the use peripheral nerve interfaces; 2) a comparison of the potentials of the different peripheral neural interfaces; 3) the possibility of extracting and appropriately interpreting the neural code for motor commands and of delivering sensory feedback by stimulating afferent fibers by using longitudinal intrafascicular electrodes; 4) a preliminary comparative analysis of the performance of this approach with the ones of others HMIs; 5) the open issues which have to be addressed for a chronic usability of this approach.
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Affiliation(s)
- Silvestro Micera
- ARTS and CRIM Laboratories, Scuola Superiore SantAnna, 56127 Pisa, Italy.
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37
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Gabi M, Sannomiya T, Larmagnac A, Puttaswamy M, Vörös J. Influence of applied currents on the viability of cells close to microelectrodes. Integr Biol (Camb) 2009; 1:108-15. [DOI: 10.1039/b814237h] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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38
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HajjHassan M, Chodavarapu V, Musallam S. NeuroMEMS: Neural Probe Microtechnologies. SENSORS 2008; 8:6704-6726. [PMID: 27873894 PMCID: PMC3707475 DOI: 10.3390/s8106704] [Citation(s) in RCA: 130] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/02/2008] [Revised: 09/27/2008] [Accepted: 10/21/2008] [Indexed: 11/25/2022]
Abstract
Neural probe technologies have already had a significant positive effect on our understanding of the brain by revealing the functioning of networks of biological neurons. Probes are implanted in different areas of the brain to record and/or stimulate specific sites in the brain. Neural probes are currently used in many clinical settings for diagnosis of brain diseases such as seizers, epilepsy, migraine, Alzheimer's, and dementia. We find these devices assisting paralyzed patients by allowing them to operate computers or robots using their neural activity. In recent years, probe technologies were assisted by rapid advancements in microfabrication and microelectronic technologies and thus are enabling highly functional and robust neural probes which are opening new and exciting avenues in neural sciences and brain machine interfaces. With a wide variety of probes that have been designed, fabricated, and tested to date, this review aims to provide an overview of the advances and recent progress in the microfabrication techniques of neural probes. In addition, we aim to highlight the challenges faced in developing and implementing ultra-long multi-site recording probes that are needed to monitor neural activity from deeper regions in the brain. Finally, we review techniques that can improve the biocompatibility of the neural probes to minimize the immune response and encourage neural growth around the electrodes for long term implantation studies.
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Affiliation(s)
- Mohamad HajjHassan
- Department of Electrical and Computer Engineering, McGill University, 3480 University Street, Montreal, Canada H3A 2A7.
| | - Vamsy Chodavarapu
- Department of Electrical and Computer Engineering, McGill University, 3480 University Street, Montreal, Canada H3A 2A7.
| | - Sam Musallam
- Department of Electrical and Computer Engineering, McGill University, 3480 University Street, Montreal, Canada H3A 2A7.
- Department of Physiology, McGill University, 3655 Promenade Osler, Montreal, Canada H3G 1Y6.
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39
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Fitzgerald JJ, Lacour SP, McMahon SB, Fawcett JW. Microchannels as axonal amplifiers. IEEE Trans Biomed Eng 2008; 55:1136-46. [PMID: 18334406 DOI: 10.1109/tbme.2007.909533] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
An implantable neural interface capable of reliable long-term high-resolution recording from peripheral nerves has yet to be developed. Device design is challenging because extracellular axonal signals are very small, decay rapidly with distance from the axon, and in myelinated fibres are concentrated close to nodes of Ranvier, which are around 1 mum long and spaced several hundred micrometers apart. We present a finite element model examining the electrical behavior of axons in microchannels, and demonstrate that confining axons in such channels substantially amplifies the extracellular signal. For example, housing a 10-microm myelinated axon in a 1-cm-long channel with a 1000-microm(2) cross section is predicted to generate a peak extracellular voltage of over 10 mV. Furthermore, there is little radial signal decay within the channel, and a smooth axial variation of signal amplitude along the channel, irrespective of node location. Additional benefits include a greater extracellular voltage generated by large myelinated fibres compared to small unmyelinated axons, and the reduction of gain to unity at the end of the channel which ensures that there can be no crosstalk with electrodes in other channels nearby. A microchannel architecture seems well suited to the requirements of a peripheral nerve interface.
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Affiliation(s)
- James J Fitzgerald
- Cambridge Centre for Brain Repair, University of Cambridge, E.D. Adrian Building, Forvie Site, Robinson Way, Cambridge CB2 2PY, UK.
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40
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Lin SP, Chen JJJ, Liao JD, Tzeng SF. Characterization of surface modification on microelectrode arrays for in vitro cell culture. Biomed Microdevices 2008; 10:99-111. [PMID: 17674208 DOI: 10.1007/s10544-007-9114-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
This study aims to investigate surface-modified microelectrodes on the microelectrode arrays (MEAs) for neuronal interfaces with in vitro cell culture. The polyimide (PI) MEA was fabricated by using micro-electro-mechanical systems (MEMS) techniques. Self-assembled monolayers (SAMs) of 11-mercaptoundecanoic acid (MUA) were utilized to modify the microelectrode surface of the MEA. The SAMs' modified surface of microelectrodes offered a reliable interface to immobilize biological ligands through covalent bonding. To increase biocompatibility, the poly-D-lysine (PDL) was immobilized on the SAMs' modified microelectrodes. Several analytical techniques were used to define the physical structure and functional groups of surface-modified gold microelectrodes on the MEA. Spectra of the Fourier transform infrared reflection (FTIR) were applied to characterize the molecular structure of MUA-SAMs and PDL on the microelectrodes. The spectra, two peaks of amide I (at 1,613 cm(-1)) and amide II (at 1,548 cm(-1)), revealed that covalent amide bonding existed in PDL-MUA-SAMs modified surfaces. The thickness and formation of the MUA and PDL were also observed and quantified by using an atomic force microscope (AFM). The impedance measurement of PDL-MUA-SAMs modified MEA only increased slightly to an average of 524.6 +/- 55.8 kOmega from 352.9 +/- 34.4 kOmega of bare gold microelectrode (p < 0.05, N = 20). In addition, the time-course changes of total impedance resulting from cell sealing resistance and gap reactance were recorded for 7 days for inferring the growth of cell lines on the electrode contact of modified MEA. The experiment of 3T3 fibroblasts, PC12 cells, primary glial cells, and primary cortical neurons cultured on the modified MEAs displayed a good adhesion rate. These biocompatibility assays demonstrated that the neuronal cells are able to grow in a proximity to PDL-MUA-SAMs modified microelectrodes of the MEAs for effective electrophysiological stimulation/sensing schemes and for future implantation purposes.
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Affiliation(s)
- Shu-Ping Lin
- Institute of Biomedical Engineering, National Cheng Kung University, No. 1 Ta-Hsueh Road, Tainan, Taiwan, Republic of China
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Selvakumaran J, Keddie JL, Ewins DJ, Hughes MP. Protein adsorption on materials for recording sites on implantable microelectrodes. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2008; 19:143-51. [PMID: 17587151 DOI: 10.1007/s10856-007-3110-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2005] [Accepted: 07/13/2006] [Indexed: 05/15/2023]
Abstract
Implantable microelectrodes have the potential to become part of neural prostheses to restore lost nerve function after nerve damage. The initial adsorption of proteins to materials for implantable microelectrodes is an important factor in determining the longevity and stability of the implant. Once an implant is in the body, protein adsorption takes place almost instantly before the cells reach the surface of an implant. The aim of this study was to identify an optimum material for electrode recording sites on implantable microelectrodes. Common materials for electrode sites are gold, platinum, iridium, and indium tin oxide. These, along with a reference material (titanium), were investigated. The thickness and the structure of adsorbed proteins on these materials were measured using a combination of atomic force microscopy and ellipsometry. The adsorbed protein layers on gold (after 7 and 28 days of exposure to serum) were the smoothest and the thinnest compared to all the other substrate materials, indicating that gold is the material of choice for electrode recording sites on implantable microelectrodes. However, the results also show that indium tin oxide might also be a good choice for these applications.
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Affiliation(s)
- Jamunanithy Selvakumaran
- Centre for Biomedical Engineering, School of Engineering, University of Surrey, Guildford, Surrey GU2 7XH, UK
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43
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Winter JO, Cogan SF, Rizzo JF. Retinal prostheses: current challenges and future outlook. JOURNAL OF BIOMATERIALS SCIENCE-POLYMER EDITION 2007; 18:1031-55. [PMID: 17705997 DOI: 10.1163/156856207781494403] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Blindness from retinal diseases, including age-related macular degeneration (AMD) and retinitis pigmentosa (RP), usually causes a significant decline in quality of life for affected patients. Currently there is no cure for these conditions. However, over the last decade, several groups have been developing retinal prostheses which hopefully will provide some degree of improved visual function to these patients. Several such devices are now in clinical trials. Unfortunately, the possibility of electrode or tissue damage limits excitation schemes to those that may be employed with electrodes that have relatively low charge densities. Further, the excitation thresholds that have been required to achieve vision to date, in general, are relatively high. This may result in part from poor apposition between neurons and the stimulating electrodes and is confounded by the effects of the photoreceptor loss, which initiates other pathology in the surviving retinal tissue. The combination of these and other factors imposes a restriction on the pixel density that can be used for devices that actively deliver electrical stimulation to the retina. The resultant use of devices with relatively low pixel densities presumably will limit the degree of visual resolution that can be obtained with these devices. Further increases in pixel density, and therefore increased visual acuity, will necessitate either improved electrode-tissue biocompatibility or lower stimulation thresholds. To meet this challenge, innovations in materials and devices have been proposed. Here, we review the types of retinal prostheses investigated, the extent of their current biocompatibility and future improvements designed to surmount these limitations.
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Affiliation(s)
- Jessica O Winter
- Center for Innovative Visual Rehabilitation, VA Medical Center, Boston, MA, USA.
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Abstract
PURPOSE To determine in vitro effects of a plasma polymerized N-isopropyl acrylamide (pNIPAM) coating for thermally controllable adhesion to retinal tissue. METHODS Polyimide (50 microm), parylene C [poly(monochloro-p-xylylene)] (20 microm), and poly(dimethyl siloxane) (PDMS) (200 microm) coated with pNIPAM were used as implant materials to test retinal adhesion in enucleated pig eyes. Following preparation of the implant materials (n = 5) and retina, the authors held the implants over the retinal tissue at 22 degrees C and gradually increased the temperature of the water bath within 15 minutes. While increasing the temperature the authors monitored the adhesion with the retina and pNIPAM coated implant. The authors measured the adhesive force by a traction test using a suture attached to the implant and a strain gauge. Then the authors checked the reversibility of the adhesion by lowering the temperature of the water bath. RESULTS There was no retinal adhesion at room temperature (22 degrees C). The adhesion developed strongly within 60 seconds after reaching the critical temperature (>or=32 degrees C). This adhesion was persistent when the authors applied tractional forces of 98 mN and 148 mN between 32 and 38 degrees C. When the authors lowered the temperature back to 22 degrees C by irrigation with cold BSS, the implants detached from the retinal surface without using any tractional force. CONCLUSION pNIPAM provides effective in vitro retinal adhesion between 32 and 38 degrees C and this adhesion is completely reversible by lowering the temperature of the physiologic medium.
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Affiliation(s)
- Murat Tunc
- Doheny Eye Institute, University of Southern California, Los Angeles, USA.
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45
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Prodanov D, Feirabend HKP. Morphometric analysis of the fiber populations of the rat sciatic nerve, its spinal roots, and its major branches. J Comp Neurol 2007; 503:85-100. [PMID: 17480027 DOI: 10.1002/cne.21375] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Correspondence between the nerve composition and the functional characteristics of its fiber populations is not always evident. To investigate such correspondence and to give a systematic picture of the morphology of the rat hind limb nerves, extensive morphometric study was performed on the sciatic nerve, its founding dorsal and ventral spinal roots, and its major branches. Nerve histology was examined in semithin sections via microscopic image analysis. Variation in the density of myelinated fibers, fiber interspace, and nerve cross-sectional area was studied in individual roots and nerves. In the dorsal roots, fiber numbers and cross-sectional areas were directly linearly proportional to the spinal root level number. Constituent fiber populations were identified using multicomponent lognormal models, and an optimal model for every nerve or root was selected by using an information theoretic approach. For the dorsal and ventral roots and the sciatic and peroneal nerves, optimal fiber population models consisted of three components, whereas, for the tibial and sural nerves, two components were optimal. Functional identities of the revealed fiber populations were established by using calculations of corresponding conduction velocities according to Arbuthnott et al. (J. Physiol. [1980] 308:125-157) and anatomical considerations. It is anticipated that morphological parameters established in this study would advance the development of neural prostheses in humans. The proximodistal correspondences among the fiber populations of different nerves were established by parametric statistical comparisons. The proposed approach provides a conceptual framework for understanding the comparative anatomy of the peripheral nerves and spinal roots and can be further applied in other species.
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Affiliation(s)
- Dimiter Prodanov
- Department of Neurosurgery, Research Laboratory, Leiden University Medical Center (LUMC), Leiden, The Netherlands
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46
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Klaver CL, Caplan MR. Bioactive surface for neural electrodes: decreasing astrocyte proliferation via transforming growth factor-beta1. J Biomed Mater Res A 2007; 81:1011-6. [PMID: 17265435 DOI: 10.1002/jbm.a.31153] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Implantation of deep-brain recording devices is a traumatic event, which inevitably elicits reactive gliosis. The ensuing glial scar encapsulating the implanted device impedes the long-term functional recording capability of the microelectrode. In this work, a bioactive surface is prepared by conjugation of transforming growth factor-beta one (TGF-beta1) and laminin to dextran, which is in turn conjugated to a biomaterial substrate. Poly-L-lysine coated surfaces are treated with oxidized dextran, and the dextran is re-oxidized with sodium metaperiodate to generate hemiacetal structures to which TGF-beta1 and laminin are covalently bound. Covalent conjugation of the ligand is confirmed by enzyme-linked immunosorbent assay. A primary cell line of astrocytes is incubated on a surface conjugated with laminin and TGF-beta1 and a surface only conjugated with laminin. Proliferation on the laminin plus TGF-beta1 surface is 57% less (p < 0.002) than the control surface (laminin alone). The results demonstrate that conjugated TGF-beta1 retains its efficacy toward astrocyte proliferation and represents a potential strategy for reducing glial scar formation in vivo.
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Affiliation(s)
- Christopher L Klaver
- Department of Chemical and Materials Engineering, Arizona State University, P.O. Box 876006, Tempe, Arizona 85287-6006, USA
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Abstract
Human embryonic stem cells (hESCs) are stable in terms of their pluripotency, karyotype, global gene expression, ability to repair DNA and maintain telomerase levels, and growth characteristics. hESCs offer a renewable source of a wide range of cell types for use in research and cell-based therapies to treat disease. Characterization of cell populations that differentiate from them provides important information on early differentiation events and critical data for subsequent downstream manipulations. A strategy that has evolved in using cells is to develop a master bank of cells from which a working bank is generated, which is then used to generate appropriate cell types for screening, drug discovery, or therapeutic use. Appropriate cells are purified or enriched by one of several selection techniques, and such purified populations are used for most purposes. In this review, the authors discuss recent results and review the progress that has been made in the field, with a focus on using embryonic stem cells for neural targets.
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Affiliation(s)
- Cleo Choong
- Laboratory of Stem Cell Biology, Singapore Stem Cell Consortium, 11 Biopolis Way, Helios 01-02, Singapore 138667.
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48
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Winter JO, Cogan SF, Rizzo JF. Neurotrophin-eluting hydrogel coatings for neural stimulating electrodes. J Biomed Mater Res B Appl Biomater 2007; 81:551-63. [PMID: 17041927 DOI: 10.1002/jbm.b.30696] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Improved sensory and motor prostheses for the central nervous system will require large numbers of electrodes with low electrical thresholds for neural excitation. With the eventual goal of reducing stimulation thresholds, we have investigated the use of biodegradable, neurotrophin-eluting hydrogels (i.e., poly(ethylene glycol)-poly(lactic acid), PEGPLA) as a means of attracting neurites to the surface of stimulating electrodes. PEGPLA hydrogels with release rates ranging from 1.5 to 3 weeks were synthesized. These hydrogels were applied to multielectrode arrays with sputtered iridium oxide charge-injection sites. The coatings had little impact on the iridium oxide electrochemical properties, including charge storage capacity, impedance, and voltage transients during current pulsing. Additionally, we quantitatively examined the ability of neurotrophin-eluting, PEGPLA hydrogels to promote neurite extension in vitro using a PC12 cell culture model. Hydrogels released neurotrophin (nerve growth factor, NGF) for at least 1 week, with neurite extension near that of an NGF positive control and much higher than extension seen from sham, bovine serum albumin-releasing boluses, and a negative control. These results show that neurotrophin-eluting hydrogels can be applied to multielectrode arrays, and suggest a method to improve neuron-electrode proximity, which could result in lowered electrical stimulation thresholds. Reduced thresholds support the creation of smaller electrode structures and high density electrode prostheses, greatly enhancing prosthesis control and function.
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Affiliation(s)
- Jessica O Winter
- Center for Innovative Visual Rehabilitation, Boston VA Hospital, Boston, Massachusetts, USA.
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49
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Abstract
Visual impairment and blindness is primarily caused by optic neuropathies like injuries and glaucomas, as well as retinopathies like agerelated macular degeneration (MD), systemic diseases like diabetes, hypertonia and hereditary retinitis pigmentosa (RP). These pathological conditions may affect retinal photoreceptors, or retinal pigment epithelium, or particular subsets of retinal neurons, and in particular retinal ganglion cells (RGCs). The RGCs which connect the retina with the brain are unique cells with extremely long axons bridging the distance from the retina to visual relays within the thalamus and midbrain, being therefore vulnerable to heterogeneous pathological conditions along this pathway. When becoming mature, RGCs loose the ability to divide and to regenerate their accidentally or experimentally injured axons. Consequently, any loss of RGCs is irreversible and results to loss of visual function. The advent of micro- and nanotechnology, and the construction of artificial implants prompted to create visual prostheses which aimed at compensating for the loss of visual function in particular cases. The purpose of the present contribution is to review the considerable engineering expertise that is essential to fabricate current visual prostheses in connection with their functional features and applicability to the animal and human eye. In this chapter, 1) Retinal and cortical implants are introduced, with particular emphasis given to the requirements they have to fulfil in order to replace very complex functions like vision. 2) Advanced work on material research is presented both from the technological and from the biocompatibility aspect as prerequisites of any perspectives for implantation. 3) Ultimately, experimental studies are presented showing the shaping of implants, the procedures of testing their biocompatibility and essential modifications to improve the interfaces between technical devices and the biological environment. The review ends by pointing to future perspectives in the rapidly accelerating process of visual prosthetics and in the increasing hope that restoration of the visual system becomes reality.
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Affiliation(s)
- S Thanos
- Department of Experimental Ophthalmology, University Eye Hospital and Interdisciplinary Centre of Clinical Research (IZKF), Münster, Germany.
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50
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Stieglitz T. Neural prostheses in clinical practice: biomedical microsystems in neurological rehabilitation. ACTA NEUROCHIRURGICA. SUPPLEMENT 2007; 97:411-8. [PMID: 17691404 DOI: 10.1007/978-3-211-33079-1_54] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Technical devices have supported physicians in diagnosis, therapy, and rehabilitation since ancient times. Neural prostheses interface parts of the nervous system with technical (micro-) systems to partially restore sensory and motor functions that have been lost due to trauma or diseases. Electrodes act as transducers to record neural signals or to excite neural cells by means of electrical stimulation. The field of neural prostheses has grown over the last decades. An overview of neural prostheses illustrates the opportunities and limitations of the implants and performance in their current size and complexity. The implementation of microsystem technology with integrated microelectronics in neural implants 20 years ago opened new fields of application, but also new design paradigms and approaches with respect to the biostability of passivation and housing concepts and electrode interfaces. Microsystem specific applications in the peripheral nervous system, vision prostheses and brain-machine interfaces show the variety of applications and the challenges in biomedical microsystems for chronic nerve interfaces in new and emerging research fields that bridge neuroscientific disciplines with material science and engineering. Different scenarios are discussed where system complexity strongly depends on the rehabilitation objective and the amount of information that is necessary for the chosen neuro-technical interface.
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Affiliation(s)
- T Stieglitz
- Laboratory for Biomedical Microtechnology, Department of Microsystems Engineering, University of Freiburg-IMTEK, Freiburg, Germany.
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