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Sait R, Al-Jawhari H, Ganash A, Wustoni S, Chen L, Hedhili MN, Wehbe N, Hussein D, Alhowity A, Baeesa S, Bangash M, Abuzenadah A, Inal S, Cross R. Electrochemical Performance of Biocompatible TiC Films Deposited through Nonreactive RF Magnetron Sputtering for Neural Interfacing. ACS Biomater Sci Eng 2024; 10:391-404. [PMID: 38095213 DOI: 10.1021/acsbiomaterials.3c01371] [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] [Indexed: 01/09/2024]
Abstract
The efficacy of neural electrode stimulation and recording hinges significantly on the choice of a neural electrode interface material. Transition metal carbides (TMCs), particularly titanium carbide (TiC), have demonstrated exceptional chemical stability and high electrical conductivity. Yet, the fabrication of TiC thin films and their potential application as neural electrode interfaces remains relatively unexplored. Herein, we present a systematic examination of TiC thin films synthesized through nonreactive radio frequency (RF) magnetron sputtering. TiC films were optimized toward high areal capacitance, low impedance, and stable electrochemical cyclability. We varied the RF power and deposition pressure to pinpoint the optimal properties, focusing on the deposition rate, surface roughness, crystallinity, and elemental composition to achieve high areal capacitance and low impedance. The best-performing TiC film showed an areal capacitance of 475 μF/cm2 with a capacitance retention of 93% after 5000 cycles. In addition, the electrochemical performance of the optimum film under varying scanning rates demonstrated a stable electrochemical performance even under dynamic and fast-changing stimulation conditions. Furthermore, the in vitro cell culture for 3 weeks revealed excellent biocompatibility, promoting cell growth compared with a control substrate. This work presents a novel contribution, highlighting the potential of sputtered TiC thin films as robust neural electrode interface materials.
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Affiliation(s)
- Roaa Sait
- Faculty of Science, Department of Physics, King Abdulaziz University, Building 7, P.O. Box 80203, Jeddah 21589, Saudi Arabia
| | - Hala Al-Jawhari
- Faculty of Science, Department of Physics, King Abdulaziz University, Building 7, P.O. Box 80203, Jeddah 21589, Saudi Arabia
| | - Aisha Ganash
- Faculty of Science, Department of Physics, King Abdulaziz University, Building 7, P.O. Box 80203, Jeddah 21589, Saudi Arabia
| | - Shofarul Wustoni
- Organic Bioelectronics Laboratory, Biological Science and Engineering Division (BESE), King Abdullah University of Science and Engineering (KAUST), Building 2, Thuwal 23955-6900, Saudi Arabia
| | - Long Chen
- Imaging and Characterization Core Laboratories, King Abdullah University of Science and Engineering (KAUST), Building 3, Thuwal 23955-6900, Saudi Arabia
| | - Mohamed Nejib Hedhili
- Imaging and Characterization Core Laboratories, King Abdullah University of Science and Engineering (KAUST), Building 3, Thuwal 23955-6900, Saudi Arabia
| | - Nimer Wehbe
- Imaging and Characterization Core Laboratories, King Abdullah University of Science and Engineering (KAUST), Building 3, Thuwal 23955-6900, Saudi Arabia
| | - Deema Hussein
- King Fahd Medical Research Center, Department of Medical Laboratory Technology, Faculty of Applied Medical Sciences, King Abdulaziz University, P.O. Box 80216, Jeddah 21589, Saudi Arabia
| | - Alazouf Alhowity
- King Fahd Medical Research Center, Department of Medical Laboratory Technology, Faculty of Applied Medical Sciences, King Abdulaziz University, P.O. Box 80216, Jeddah 21589, Saudi Arabia
| | - Saleh Baeesa
- King Fahd Medical Research Center, Department of Medical Laboratory Technology, Faculty of Applied Medical Sciences, King Abdulaziz University, P.O. Box 80216, Jeddah 21589, Saudi Arabia
| | - Mohammed Bangash
- King Fahd Medical Research Center, Department of Medical Laboratory Technology, Faculty of Applied Medical Sciences, King Abdulaziz University, P.O. Box 80216, Jeddah 21589, Saudi Arabia
| | - Adel Abuzenadah
- King Fahd Medical Research Center, Department of Medical Laboratory Technology, Faculty of Applied Medical Sciences, King Abdulaziz University, P.O. Box 80216, Jeddah 21589, Saudi Arabia
| | - Sahika Inal
- Organic Bioelectronics Laboratory, Biological Science and Engineering Division (BESE), King Abdullah University of Science and Engineering (KAUST), Building 2, Thuwal 23955-6900, Saudi Arabia
| | - Richard Cross
- Emerging Technology Research Center, De Montfort University, The Gateway, Leicester LE1 9BH, United Kingdom
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2
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Muguet I, Maziz A, Mathieu F, Mazenq L, Larrieu G. Combining PEDOT:PSS Polymer Coating with Metallic 3D Nanowires Electrodes to Achieve High Electrochemical Performances for Neuronal Interfacing Applications. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2302472. [PMID: 37385261 DOI: 10.1002/adma.202302472] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Revised: 05/18/2023] [Accepted: 05/26/2023] [Indexed: 07/01/2023]
Abstract
This study presents a novel approach to improve the performance of microelectrode arrays (MEAs) used for electrophysiological studies of neuronal networks. The integration of 3D nanowires (NWs) with MEAs increases the surface-to-volume ratio, which enables subcellular interactions and high-resolution neuronal signal recording. However, these devices suffer from high initial interface impedance and limited charge transfer capacity due to their small effective area. To overcome these limitations, the integration of conductive polymer coatings, poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) is investigated as a mean of improving the charge transfer capacity and biocompatibility of MEAs. The study combines platinum silicide-based metallic 3D nanowires electrodes with electrodeposited PEDOT:PSS coatings to deposit ultra-thin (<50 nm) layers of conductive polymer onto metallic electrodes with very high selectivity. The polymer-coated electrodes were fully characterized electrochemically and morphologically to establish a direct relationship between synthesis conditions, morphology, and conductive features. Results show that PEDOT-coated electrodes exhibit thickness-dependent improved stimulation and recording performances, offering new perspectives for neuronal interfacing with optimal cell engulfment to enable the study of neuronal activity with acute spatial and signal resolution at the sub-cellular level.
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Affiliation(s)
- Ines Muguet
- LAAS-CNRS, Université de Toulouse, CNRS, 7 avenue du colonel Roche, Toulouse, F-31400, France
| | - Ali Maziz
- LAAS-CNRS, Université de Toulouse, CNRS, 7 avenue du colonel Roche, Toulouse, F-31400, France
| | - Fabrice Mathieu
- LAAS-CNRS, Université de Toulouse, CNRS, 7 avenue du colonel Roche, Toulouse, F-31400, France
| | - Laurent Mazenq
- LAAS-CNRS, Université de Toulouse, CNRS, 7 avenue du colonel Roche, Toulouse, F-31400, France
| | - Guilhem Larrieu
- LAAS-CNRS, Université de Toulouse, CNRS, 7 avenue du colonel Roche, Toulouse, F-31400, France
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Matter L, Harland B, Raos B, Svirskis D, Asplund M. Generation of direct current electrical fields as regenerative therapy for spinal cord injury: A review. APL Bioeng 2023; 7:031505. [PMID: 37736015 PMCID: PMC10511262 DOI: 10.1063/5.0152669] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Accepted: 08/21/2023] [Indexed: 09/23/2023] Open
Abstract
Electrical stimulation (ES) shows promise as a therapy to promote recovery and regeneration after spinal cord injury. ES therapy establishes beneficial electric fields (EFs) and has been investigated in numerous studies, which date back nearly a century. In this review, we discuss the various engineering approaches available to generate regenerative EFs through direct current electrical stimulation and very low frequency electrical stimulation. We highlight the electrode-tissue interface, which is important for the appropriate choice of electrode material and stimulator circuitry. We discuss how to best estimate and control the generated field, which is an important measure for comparability of studies. Finally, we assess the methods used in these studies to measure functional recovery after the injury and treatment. This work reviews studies in the field of ES therapy with the goal of supporting decisions regarding best stimulation strategy and recovery assessment for future work.
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Affiliation(s)
- Lukas Matter
- Author to whom correspondence should be addressed:
| | - Bruce Harland
- School of Pharmacy, The University of Auckland, NZ 1023 Auckland, New Zealand
| | - Brad Raos
- School of Pharmacy, The University of Auckland, NZ 1023 Auckland, New Zealand
| | - Darren Svirskis
- School of Pharmacy, The University of Auckland, NZ 1023 Auckland, New Zealand
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4
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Solazzo M, Monaghan MG. A Workflow to Produce a Low-Cost In Vitro Platform for the Electric-Field Pacing of Cellularised 3D Porous Scaffolds. ACS Biomater Sci Eng 2023; 9:4573-4582. [PMID: 37531298 PMCID: PMC10428090 DOI: 10.1021/acsbiomaterials.3c00756] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Accepted: 07/20/2023] [Indexed: 08/04/2023]
Abstract
Endogenous electrically mediated signaling is a key feature of most native tissues, the most notable examples being the nervous and the cardiac systems. Biomedical engineering often aims to harness and drive such activity in vitro, in bioreactors to study cell disease and differentiation, and often in three-dimensional (3D) formats with the help of biomaterials, with most of these approaches adopting scaffold-free self-assembling strategies to create 3D tissues. In essence, this is the casting of gels which self-assemble in response to factors such as temperature or pH and have capacity to harbor cells during this process without imparting toxicity. However, the use of materials that do not self-assemble but can support 3D encapsulation of cells (such as porous scaffolds) warrants consideration given the larger repertoire this would provide in terms of material physicochemical properties and microstructure. In this method and protocol paper, we detail and provide design codes and assembly instructions to cheaply create an electrical pacing bioreactor and a Rig for Stimulation of Sponge-like Scaffolds (R3S). This setup has also been engineered to simultaneously perform live optical imaging of the in vitro models. To showcase a pilot exploration of material physiochemistry (in this aspect material conductivity) and microstructure (isotropy versus anisotropy), we adopt isotropic and anisotropic porous scaffolds composed of collagen or poly(3,4-ethylene dioxythiophene):polystyrenesulfonate (PEDOT:PSS) for their contrasting conductivity properties yet similar in porosity and mechanical integrity. Electric field pacing of mouse C3H10 cells on anisotropic porous scaffolds placed in R3S led to increased metabolic activity and enhanced cell alignment. Furthermore, after 7 days electrical pacing drove C3H10 alignment regardless of material conductivity or anisotropy. This platform and its design, which we have shared, have wide suitability for the study of electrical pacing of cellularized scaffolds in 3D in vitro cultures.
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Affiliation(s)
- Matteo Solazzo
- Department
of Mechanical, Manufacturing and Biomedical Engineering, Trinity College Dublin, 152−160 Pearse Street, Dublin 2, Ireland
- Trinity
Centre for Biomedical Engineering, 152-160 Pearse Street, Dublin 2, Ireland
| | - Michael G. Monaghan
- Department
of Mechanical, Manufacturing and Biomedical Engineering, Trinity College Dublin, 152−160 Pearse Street, Dublin 2, Ireland
- Advanced
Materials and BioEngineering Research (AMBER) Centre at Trinity College Dublin and the Royal College of Surgeons
in Ireland, Dublin 2, Ireland
- CÚRAM,
Centre for Research in Medical Devices, National University of Ireland, Galway, Newcastle Road, Galway H91 W2TY, Ireland
- Trinity
Centre for Biomedical Engineering, 152-160 Pearse Street, Dublin 2, Ireland
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5
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Zeng Q, Yu S, Fan Z, Huang Y, Song B, Zhou T. Nanocone-Array-Based Platinum-Iridium Oxide Neural Microelectrodes: Structure, Electrochemistry, Durability and Biocompatibility Study. NANOMATERIALS (BASEL, SWITZERLAND) 2022; 12:nano12193445. [PMID: 36234573 PMCID: PMC9565584 DOI: 10.3390/nano12193445] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Revised: 09/23/2022] [Accepted: 09/28/2022] [Indexed: 05/14/2023]
Abstract
Neural interfaces provide a window for bio-signal modulation and recording with the assistance of neural microelectrodes. However, shrinking the size of electrodes results in high electrochemical impedance and low capacitance, thus limiting the stimulation/recording efficiency. In order to achieve critical stability and low power consumption, here, nanocone-shaped platinum (Pt) with an extensive surface area is proposed as an adhesive layer on a bare Pt substrate, followed by the deposition of a thin layer of iridium oxide (IrOx) to fabricate high-performance nanocone-array-based Pt-IrOx neural microelectrodes (200 μm in diameter). A uniform nanocone-shaped Pt with significant roughness is created via controlling the ratio of NH4+ and Pt4+ ions in the electrolyte, which can be widely applicable for batch production on multichannel flexible microelectrode arrays (fMEAs) and various substrates with different dimensions. The Pt-IrOx nanocomposite-coated microelectrode presents a significantly low impedance down to 0.72 ± 0.04 Ω cm2 at 1 kHz (reduction of ~92.95%). The cathodic charge storage capacity (CSCc) and charge injection capacity (CIC) reaches up to 52.44 ± 2.53 mC cm-2 and 4.39 ± 0.36 mC cm-2, respectively. Moreover, superior chronic stability and biocompatibility are also observed. The modified microelectrodes significantly enhance the adhesion of microglia, the major immune cells in the central nervous system. Therefore, such a coating strategy presents great potential for biomedical and other practical applications.
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Affiliation(s)
- Qi Zeng
- Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
- College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen 518061, China
- Correspondence: (Q.Z.); (B.S.); (T.Z.)
| | - Shoujun Yu
- Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
| | - Zihui Fan
- Institutes of Biomedical Sciences, Fudan University, Shanghai 200032, China
| | - Yubin Huang
- Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
| | - Bing Song
- Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
- Correspondence: (Q.Z.); (B.S.); (T.Z.)
| | - Tian Zhou
- Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
- Correspondence: (Q.Z.); (B.S.); (T.Z.)
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6
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Cho YH, Park YG, Kim S, Park JU. 3D Electrodes for Bioelectronics. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2021; 33:e2005805. [PMID: 34013548 DOI: 10.1002/adma.202005805] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Revised: 10/04/2020] [Indexed: 05/08/2023]
Abstract
In recent studies related to bioelectronics, significant efforts have been made to form 3D electrodes to increase the effective surface area or to optimize the transfer of signals at tissue-electrode interfaces. Although bioelectronic devices with 2D and flat electrode structures have been used extensively for monitoring biological signals, these 2D planar electrodes have made it difficult to form biocompatible and uniform interfaces with nonplanar and soft biological systems (at the cellular or tissue levels). Especially, recent biomedical applications have been expanding rapidly toward 3D organoids and the deep tissues of living animals, and 3D bioelectrodes are getting significant attention because they can reach the deep regions of various 3D tissues. An overview of recent studies on 3D bioelectronic devices, such as the use of electrical stimulations and the recording of neural signals from biological subjects, is presented. Subsequently, the recent developments in materials and fabrication processing to 3D micro- and nanostructures are introduced, followed by broad applications of these 3D bioelectronic devices at various in vitro and in vivo conditions.
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Affiliation(s)
- Yo Han Cho
- Nano Science Technology Institute, Department of Materials Science and Engineering, Yonsei University, Seoul, 03722, Republic of Korea
- Center for Nanomedicine, Institute for Basic Science (IBS), Seoul, 03722, Republic of Korea
- Graduate Program of Nano Biomedical Engineering (NanoBME), Advanced Science Institute, Yonsei University, Seoul, 03722, Republic of Korea
| | - Young-Geun Park
- Nano Science Technology Institute, Department of Materials Science and Engineering, Yonsei University, Seoul, 03722, Republic of Korea
- Center for Nanomedicine, Institute for Basic Science (IBS), Seoul, 03722, Republic of Korea
- Graduate Program of Nano Biomedical Engineering (NanoBME), Advanced Science Institute, Yonsei University, Seoul, 03722, Republic of Korea
| | - Sumin Kim
- Nano Science Technology Institute, Department of Materials Science and Engineering, Yonsei University, Seoul, 03722, Republic of Korea
- Center for Nanomedicine, Institute for Basic Science (IBS), Seoul, 03722, Republic of Korea
- Graduate Program of Nano Biomedical Engineering (NanoBME), Advanced Science Institute, Yonsei University, Seoul, 03722, Republic of Korea
| | - Jang-Ung Park
- Nano Science Technology Institute, Department of Materials Science and Engineering, Yonsei University, Seoul, 03722, Republic of Korea
- Center for Nanomedicine, Institute for Basic Science (IBS), Seoul, 03722, Republic of Korea
- Graduate Program of Nano Biomedical Engineering (NanoBME), Advanced Science Institute, Yonsei University, Seoul, 03722, Republic of Korea
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7
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Luo Y, Li J, Li B, Xia Y, Wang H, Fu C. Physical Cues of Matrices Reeducate Nerve Cells. Front Cell Dev Biol 2021; 9:731170. [PMID: 34646825 PMCID: PMC8502847 DOI: 10.3389/fcell.2021.731170] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2021] [Accepted: 08/20/2021] [Indexed: 11/15/2022] Open
Abstract
The behavior of nerve cells plays a crucial role in nerve regeneration. The mechanical, topographical, and electrical microenvironment surrounding nerve cells can activate cellular signaling pathways of mechanical transduction to affect the behavior of nerve cells. Recently, biological scaffolds with various physical properties have been developed as extracellular matrix to regulate the behavior conversion of nerve cell, such as neuronal neurite growth and directional differentiation of neural stem cells, providing a robust driving force for nerve regeneration. This review mainly focused on the biological basis of nerve cells in mechanical transduction. In addition, we also highlighted the effect of the physical cues, including stiffness, mechanical tension, two-dimensional terrain, and electrical conductivity, on neurite outgrowth and differentiation of neural stem cells and predicted their potential application in clinical nerve tissue engineering.
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Affiliation(s)
- Yiqian Luo
- Department of Spine Surgery, The First Hospital of Jilin University, Changchun, China
| | - Jie Li
- Department of Spine Surgery, The First Hospital of Jilin University, Changchun, China
| | - Baoqin Li
- Department of Spine Surgery, The First Hospital of Jilin University, Changchun, China
| | - Yuanliang Xia
- Department of Spine Surgery, The First Hospital of Jilin University, Changchun, China
| | - Hengyi Wang
- Department of Spine Surgery, The First Hospital of Jilin University, Changchun, China
| | - Changfeng Fu
- Department of Spine Surgery, The First Hospital of Jilin University, Changchun, China
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8
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Seaton BT, Heien ML. Biocompatible reference electrodes to enhance chronic electrochemical signal fidelity in vivo. Anal Bioanal Chem 2021; 413:6689-6701. [PMID: 34595560 DOI: 10.1007/s00216-021-03640-w] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Revised: 08/27/2021] [Accepted: 08/30/2021] [Indexed: 12/17/2022]
Abstract
In vivo electrochemistry is a vital tool of neuroscience that allows for the detection, identification, and quantification of neurotransmitters, their metabolites, and other important analytes. One important goal of in vivo electrochemistry is a better understanding of progressive neurological disorders (e.g., Parkinson's disease). A complete understanding of such disorders can only be achieved through a combination of acute (i.e., minutes to hours) and chronic (i.e., days or longer) experimentation. Chronic studies are more challenging because they require prolonged implantation of electrodes, which elicits an immune response, leading to glial encapsulation of the electrodes and altered electrode performance (i.e., biofouling). Biofouling leads to increased electrode impedance and reference electrode polarization, both of which diminish the selectivity and sensitivity of in vivo electrochemical measurements. The increased impedance factor has been successfully mitigated previously with the use of a counter electrode, but the challenge of reference electrode polarization remains. The commonly used Ag/AgCl reference electrode lacks the long-term potential stability in vivo required for chronic measurements. In addition, the cytotoxicity of Ag/AgCl adversely affects animal experimentation and prohibits implantation in humans, hindering translational research progress. Thus, a move toward biocompatible reference electrodes with superior chronic potential stability is necessary. Two qualifying materials, iridium oxide and boron-doped diamond, are introduced and discussed in terms of their electrochemical properties, biocompatibilities, fabrication methods, and applications. In vivo electrochemistry continues to advance toward more chronic experimentation in both animal models and humans, necessitating the utilization of biocompatible reference electrodes that should provide superior potential stability and allow for unprecedented chronic signal fidelity when used with a counter electrode for impedance mitigation.
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Affiliation(s)
- Blake T Seaton
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ, 85721, USA
| | - Michael L Heien
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ, 85721, USA.
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9
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Yin P, Liu Y, Xiao L, Zhang C. Advanced Metallic and Polymeric Coatings for Neural Interfacing: Structures, Properties and Tissue Responses. Polymers (Basel) 2021; 13:2834. [PMID: 34451372 PMCID: PMC8401399 DOI: 10.3390/polym13162834] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Revised: 08/15/2021] [Accepted: 08/17/2021] [Indexed: 02/07/2023] Open
Abstract
Neural electrodes are essential for nerve signal recording, neurostimulation, neuroprosthetics and neuroregeneration, which are critical for the advancement of brain science and the establishment of the next-generation brain-electronic interface, central nerve system therapeutics and artificial intelligence. However, the existing neural electrodes suffer from drawbacks such as foreign body responses, low sensitivity and limited functionalities. In order to overcome the drawbacks, efforts have been made to create new constructions and configurations of neural electrodes from soft materials, but it is also more practical and economic to improve the functionalities of the existing neural electrodes via surface coatings. In this article, recently reported surface coatings for neural electrodes are carefully categorized and analyzed. The coatings are classified into different categories based on their chemical compositions, i.e., metals, metal oxides, carbons, conducting polymers and hydrogels. The characteristic microstructures, electrochemical properties and fabrication methods of the coatings are comprehensively presented, and their structure-property correlations are discussed. Special focus is given to the biocompatibilities of the coatings, including their foreign-body response, cell affinity, and long-term stability during implantation. This review article can provide useful and sophisticated insights into the functional design, material selection and structural configuration for the next-generation multifunctional coatings of neural electrodes.
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Affiliation(s)
| | - Yang Liu
- Department of Biomedical Engineering, Sun Yat-sen University, Shenzhen 518107, China; (P.Y.); (L.X.)
| | | | - Chao Zhang
- Department of Biomedical Engineering, Sun Yat-sen University, Shenzhen 518107, China; (P.Y.); (L.X.)
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10
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Zheng XS, Tan C, Castagnola E, Cui XT. Electrode Materials for Chronic Electrical Microstimulation. Adv Healthc Mater 2021; 10:e2100119. [PMID: 34029008 PMCID: PMC8257249 DOI: 10.1002/adhm.202100119] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Revised: 04/20/2021] [Indexed: 02/06/2023]
Abstract
Electrical microstimulation has enabled partial restoration of vision, hearing, movement, somatosensation, as well as improving organ functions by electrically modulating neural activities. However, chronic microstimulation is faced with numerous challenges. The implantation of an electrode array into the neural tissue triggers an inflammatory response, which can be exacerbated by the delivery of electrical currents. Meanwhile, prolonged stimulation may lead to electrode material degradation., which can be accelerated by the hostile inflammatory environment. Both material degradation and adverse tissue reactions can compromise stimulation performance over time. For stable chronic electrical stimulation, an ideal microelectrode must present 1) high charge injection limit, to efficiently deliver charge without exceeding safety limits for both tissue and electrodes, 2) small size, to gain high spatial selectivity, 3) excellent biocompatibility that ensures tissue health immediately next to the device, and 4) stable in vivo electrochemical properties over the application period. In this review, the challenges in chronic microstimulation are described in detail. To aid material scientists interested in neural stimulation research, the in vitro and in vivo testing methods are introduced for assessing stimulation functionality and longevity and a detailed overview of recent advances in electrode material research and device fabrication for improving chronic microstimulation performance is provided.
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Affiliation(s)
- Xin Sally Zheng
- Department of Bioengineering, University of Pittsburgh, 3501 Fifth Ave. Pittsburgh, Pittsburgh, PA, 15213, USA
| | - Chao Tan
- Department of Bioengineering, University of Pittsburgh, 3501 Fifth Ave. Pittsburgh, Pittsburgh, PA, 15213, USA
| | - Elisa Castagnola
- Department of Bioengineering, University of Pittsburgh, 3501 Fifth Ave. Pittsburgh, Pittsburgh, PA, 15213, USA
| | - Xinyan Tracy Cui
- Department of Bioengineering, University of Pittsburgh, 3501 Fifth Ave. Pittsburgh, Pittsburgh, PA, 15213, USA
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11
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Hejazi M, Tong W, Ibbotson MR, Prawer S, Garrett DJ. Advances in Carbon-Based Microfiber Electrodes for Neural Interfacing. Front Neurosci 2021; 15:658703. [PMID: 33912007 PMCID: PMC8072048 DOI: 10.3389/fnins.2021.658703] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Accepted: 03/22/2021] [Indexed: 12/20/2022] Open
Abstract
Neural interfacing devices using penetrating microelectrode arrays have emerged as an important tool in both neuroscience research and medical applications. These implantable microelectrode arrays enable communication between man-made devices and the nervous system by detecting and/or evoking neuronal activities. Recent years have seen rapid development of electrodes fabricated using flexible, ultrathin carbon-based microfibers. Compared to electrodes fabricated using rigid materials and larger cross-sections, these microfiber electrodes have been shown to reduce foreign body responses after implantation, with improved signal-to-noise ratio for neural recording and enhanced resolution for neural stimulation. Here, we review recent progress of carbon-based microfiber electrodes in terms of material composition and fabrication technology. The remaining challenges and future directions for development of these arrays will also be discussed. Overall, these microfiber electrodes are expected to improve the longevity and reliability of neural interfacing devices.
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Affiliation(s)
- Maryam Hejazi
- School of Physics, The University of Melbourne, Parkville, VIC, Australia
| | - Wei Tong
- School of Physics, The University of Melbourne, Parkville, VIC, Australia
- National Vision Research Institute, The Australian College of Optometry, Carlton, VIC, Australia
| | - Michael R. Ibbotson
- National Vision Research Institute, The Australian College of Optometry, Carlton, VIC, Australia
- Department of Optometry and Vision Sciences, The University of Melbourne, Parkville, VIC, Australia
| | - Steven Prawer
- School of Physics, The University of Melbourne, Parkville, VIC, Australia
| | - David J. Garrett
- School of Physics, The University of Melbourne, Parkville, VIC, Australia
- School of Engineering, RMIT University, Melbourne, VIC, Australia
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12
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Karimi-Soflou R, Nejati S, Karkhaneh A. Electroactive and antioxidant injectable in-situ forming hydrogels with tunable properties by polyethylenimine and polyaniline for nerve tissue engineering. Colloids Surf B Biointerfaces 2021; 199:111565. [DOI: 10.1016/j.colsurfb.2021.111565] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Revised: 01/02/2021] [Accepted: 01/05/2021] [Indexed: 12/27/2022]
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13
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López L, Hernández N, Reyes Morales J, Cruz J, Flores K, González-Amoretti J, Rivera V, Cunci L. Measurement of Neuropeptide Y Using Aptamer-Modified Microelectrodes by Electrochemical Impedance Spectroscopy. Anal Chem 2021; 93:973-980. [PMID: 33297678 PMCID: PMC7856015 DOI: 10.1021/acs.analchem.0c03719] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Aptamer-modified microelectrodes for Neuropeptide Y measurement by electrochemical impedance spectroscopy was described here. The advantages of using carbon fiber or platinum microelectrodes are because they are promising materials with high electrical conductivity, chemical stability, and high surface area that can be easily modified on their surface. The immobilization and biofouling were studied and compared using EIS. Moreover, the adsorption of NPY to the aptamer-modified microelectrodes was also demonstrated by EIS. Changes of -ω*Zimag, an impedance factor that gives information of the capacitance, is directly correlated with concentrations. A widely linear range was obtained from 10 to 1000 ng/mL of NPY. This method was able to detect NPY without performing a redox reaction by adsorption at the surface of the microelectrodes, with the specificity provided by aptamer functionalization of the microelectrode surface.
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Affiliation(s)
- Luis López
- Department of Chemistry, Universidad Ana G. Méndez, Carr. 189, Km 3.3, Gurabo, Puerto Rico 00778, United States
| | - Nerika Hernández
- Department of Chemistry, Universidad Ana G. Méndez, Carr. 189, Km 3.3, Gurabo, Puerto Rico 00778, United States
| | - Joshua Reyes Morales
- Department of Chemistry, Universidad Ana G. Méndez, Carr. 189, Km 3.3, Gurabo, Puerto Rico 00778, United States
| | - John Cruz
- Department of Chemistry, Universidad Ana G. Méndez, Carr. 189, Km 3.3, Gurabo, Puerto Rico 00778, United States
| | - Krystal Flores
- Department of Chemistry, Universidad Ana G. Méndez, Carr. 189, Km 3.3, Gurabo, Puerto Rico 00778, United States
| | - John González-Amoretti
- Department of Chemistry, Universidad Ana G. Méndez, Carr. 189, Km 3.3, Gurabo, Puerto Rico 00778, United States
| | - Vitmary Rivera
- Department of Chemistry, Universidad Ana G. Méndez, Carr. 189, Km 3.3, Gurabo, Puerto Rico 00778, United States
| | - Lisandro Cunci
- Department of Chemistry, Universidad Ana G. Méndez, Carr. 189, Km 3.3, Gurabo, Puerto Rico 00778, United States
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14
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Volatile Iridium and Platinum MOCVD Precursors: Chemistry, Thermal Properties, Materials and Prospects for Their Application in Medicine. COATINGS 2021. [DOI: 10.3390/coatings11010078] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Interest in iridium and platinum has been steadily encouraged due to such unique properties as exceptional chemical inertia and corrosion resistance, high biological compatibility, and mechanical strength, which are the basis for their application in medical practice. Metal-organic chemical vapor deposition (MOCVD) is a promising method to fabricate Ir and Pt nanomaterials, multilayers, and heterostructures. Its advantages include precise control of the material composition and microstructure in deposition processes at relatively low temperatures onto non-planar substrates. The development of MOCVD processes is inextricably linked with the development of the chemistry of volatile precursors, viz., specially designed coordination and organometallic compounds. This review describes the synthesis methods of various iridium and platinum precursors, their thermal properties, and examples of the use of MOCVD, including formation of films for medical application and bimetallics. Although metal acetylacetonates are currently the most widely used precursors, the recently developed heteroligand Ir(I) and Pt(IV) complexes appear to be more promising in both synthetic and thermochemical aspects. Their main advantage is their ability to control thermal properties by modifying several types of ligands, making them tunable to deposit films onto different types of materials and to select a combination of compatible compounds for obtaining the bimetallic materials.
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15
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Conducting Polymer-Based Composite Materials for Therapeutic Implantations: From Advanced Drug Delivery System to Minimally Invasive Electronics. INT J POLYM SCI 2020. [DOI: 10.1155/2020/5659682] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Conducting polymer-based composites have recently becoming popular in both academic research and industrial practices due to their high conductivity, ease of process, and tunable electrical properties. The multifunctional conducting polymer-based composites demonstrated great application potential for in vivo therapeutics and implantable electronics, including drug delivery, neural interfacing, and minimally invasive electronics. In this review article, the state-of-the-art conducting polymer-based composites in the mentioned biological fields are discussed and summarized. The recent progress on the synthesis, structure, properties, and application of the conducting polymer-based composites is presented, aimed at revealing the structure-property relationship and the corresponding functional applications of the conducting polymer-based composites. Furthermore, key issues and challenges regarding the implantation performance of these composites are highlighted in this paper.
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16
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Yang W, Gong Y, Li W. A Review: Electrode and Packaging Materials for Neurophysiology Recording Implants. Front Bioeng Biotechnol 2020; 8:622923. [PMID: 33585422 PMCID: PMC7873964 DOI: 10.3389/fbioe.2020.622923] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Accepted: 12/10/2020] [Indexed: 01/28/2023] Open
Abstract
To date, a wide variety of neural tissue implants have been developed for neurophysiology recording from living tissues. An ideal neural implant should minimize the damage to the tissue and perform reliably and accurately for long periods of time. Therefore, the materials utilized to fabricate the neural recording implants become a critical factor. The materials of these devices could be classified into two broad categories: electrode materials as well as packaging and substrate materials. In this review, inorganic (metals and semiconductors), organic (conducting polymers), and carbon-based (graphene and carbon nanostructures) electrode materials are reviewed individually in terms of various neural recording devices that are reported in recent years. Properties of these materials, including electrical properties, mechanical properties, stability, biodegradability/bioresorbability, biocompatibility, and optical properties, and their critical importance to neural recording quality and device capabilities, are discussed. For the packaging and substrate materials, different material properties are desired for the chronic implantation of devices in the complex environment of the body, such as biocompatibility and moisture and gas hermeticity. This review summarizes common solid and soft packaging materials used in a variety of neural interface electrode designs, as well as their packaging performances. Besides, several biopolymers typically applied over the electrode package to reinforce the mechanical rigidity of devices during insertion, or to reduce the immune response and inflammation at the device-tissue interfaces are highlighted. Finally, a benchmark analysis of the discussed materials and an outlook of the future research trends are concluded.
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Affiliation(s)
- Weiyang Yang
- Microtechnology Lab, Department of Electrical and Computer Engineering, Michigan State University, East Lansing, MI, United States
| | - Yan Gong
- Microtechnology Lab, Department of Electrical and Computer Engineering, Michigan State University, East Lansing, MI, United States
| | - Wen Li
- Microtechnology Lab, Department of Electrical and Computer Engineering, Michigan State University, East Lansing, MI, United States
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17
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Chen C, Bai X, Ding Y, Lee IS. Electrical stimulation as a novel tool for regulating cell behavior in tissue engineering. Biomater Res 2019; 23:25. [PMID: 31844552 PMCID: PMC6896676 DOI: 10.1186/s40824-019-0176-8] [Citation(s) in RCA: 185] [Impact Index Per Article: 37.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Accepted: 11/27/2019] [Indexed: 12/18/2022] Open
Abstract
Recently, electrical stimulation as a physical stimulus draws lots of attention. It shows great potential in disease treatment, wound healing, and mechanism study because of significant experimental performance. Electrical stimulation can activate many intracellular signaling pathways, and influence intracellular microenvironment, as a result, affect cell migration, cell proliferation, and cell differentiation. Electrical stimulation is using in tissue engineering as a novel type of tool in regeneration medicine. Besides, with the advantages of biocompatible conductive materials coming into view, the combination of electrical stimulation with suitable tissue engineered scaffolds can well combine the benefits of both and is ideal for the field of regenerative medicine. In this review, we summarize the various materials and latest technologies to deliver electrical stimulation. The influences of electrical stimulation on cell alignment, migration and its underlying mechanisms are discussed. Then the effect of electrical stimulation on cell proliferation and differentiation are also discussed.
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Affiliation(s)
- Cen Chen
- College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou, 310018 People’s Republic of China
- Zhejiang Provincial Key Laboratory of Silkworm Bioreactor and Biomedicine, Hangzhou, 310018 People’s Republic of China
| | - Xue Bai
- College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou, 310018 People’s Republic of China
| | - Yahui Ding
- Department of Cardiology, Zhejiang Provincial People’s Hospital, Hangzhou, 310014 People’s Republic of China
- People’s Hospital of Hangzhou Medical College, Hangzhou, 310014 People’s Republic of China
| | - In-Seop Lee
- Institute of Natural Sciences, Yonsei University, 134 Shinchon-dong, Seodaemoon-gu, Seoul, 03722 Republic of Korea
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