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Li T, Jiang Y, Fu X, Sun Z, Yan Y, Li YF, Liu S. Nanorobot-Based Direct Implantation of Flexible Neural Electrode for BCI. IEEE Trans Biomed Eng 2024; 71:3014-3023. [PMID: 38913534 DOI: 10.1109/tbme.2024.3406940] [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: 06/26/2024]
Abstract
Brain-Computer Interface (BCI) has gained remarkable prominence in biomedical community. While BCI holds vast potential across diverse domains, the implantation of neural electrodes poses multifaceted challenges to fully explore the power of BCI. Conventional rigid electrodes face the problem of foreign body reaction induced by mechanical mismatch to biological tissue, while flexible electrodes, though more preferential, lack controllability during implantation. Researchers have explored various strategies, from assistive shuttle to biodegradable coatings, to strike a balance between implantation rigidity and post-implantation flexibility. Yet, these approaches may introduce complications, including immune response, inflammations, and raising intracranial pressure. To this end, this paper proposes a novel nanorobot-based technique for direct implantation of flexible neural electrodes, leveraging the high controllability and repeatability of robotics to enhance the implantation quality. This approach features a dual-arm nanorobotic system equipped with stereo microscope, by which a flexible electrode is first visually aligned to the target neural tissue to establish contact and thereafter implanted into brain with well controlled insertion direction and depth. The key innovation is, through dual-arm coordination, the flexible electrode maintains straight along the implantation direction. With this approach, we implanted CNTf electrodes into cerebral cortex of mouse, and captured standard spiking neural signals.
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Yi D, Yao Y, Wang Y, Chen L. Design, Fabrication, and Implantation of Invasive Microelectrode Arrays as in vivo Brain Machine Interfaces: A Comprehensive Review. JOURNAL OF MANUFACTURING PROCESSES 2024; 126:185-207. [PMID: 39185373 PMCID: PMC11340637 DOI: 10.1016/j.jmapro.2024.07.100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/27/2024]
Abstract
Invasive Microelectrode Arrays (MEAs) have been a significant and useful tool for us to gain a fundamental understanding of how the brain works through high spatiotemporal resolution neuron-level recordings and/or stimulations. Through decades of research, various types of microwire, silicon, and flexible substrate-based MEAs have been developed using the evolving new materials, novel design concepts, and cutting-edge advanced manufacturing capabilities. Surgical implantation of the latest minimal damaging flexible MEAs through the hard-to-penetrate brain membranes introduces new challenges and thus the development of implantation strategies and instruments for the latest MEAs. In this paper, studies on the design considerations and enabling manufacturing processes of various invasive MEAs as in vivo brain-machine interfaces have been reviewed to facilitate the development as well as the state-of-art of such brain-machine interfaces from an engineering perspective. The challenges and solution strategies developed for surgically implanting such interfaces into the brain have also been evaluated and summarized. Finally, the research gaps have been identified in the design, manufacturing, and implantation perspectives, and future research prospects in invasive MEA development have been proposed.
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Affiliation(s)
- Dongyang Yi
- Department of Mechanical and Industrial Engineering, University of Massachusetts Lowell, Lowell, MA 01854
| | - Yao Yao
- Department of Industrial and Systems Engineering, University of Missouri, Columbia, MO 65211
| | - Yi Wang
- Department of Industrial and Systems Engineering, University of Missouri, Columbia, MO 65211
| | - Lei Chen
- Department of Mechanical and Industrial Engineering, University of Massachusetts Lowell, Lowell, MA 01854
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Malekoshoaraie MH, Wu B, Krahe DD, Ahmed Z, Pupa S, Jain V, Cui XT, Chamanzar M. Fully flexible implantable neural probes for electrophysiology recording and controlled neurochemical modulation. MICROSYSTEMS & NANOENGINEERING 2024; 10:91. [PMID: 38947533 PMCID: PMC11211464 DOI: 10.1038/s41378-024-00685-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/03/2023] [Revised: 02/01/2024] [Accepted: 02/28/2024] [Indexed: 07/02/2024]
Abstract
Targeted delivery of neurochemicals and biomolecules for neuromodulation of brain activity is a powerful technique that, in addition to electrical recording and stimulation, enables a more thorough investigation of neural circuit dynamics. We have designed a novel, flexible, implantable neural probe capable of controlled, localized chemical stimulation and electrophysiology recording. The neural probe was implemented using planar micromachining processes on Parylene C, a mechanically flexible, biocompatible substrate. The probe shank features two large microelectrodes (chemical sites) for drug loading and sixteen small microelectrodes for electrophysiology recording to monitor neuronal response to drug release. To reduce the impedance while keeping the size of the microelectrodes small, poly(3,4-ethylenedioxythiophene) (PEDOT) was electrochemically coated on recording microelectrodes. In addition, PEDOT doped with mesoporous sulfonated silica nanoparticles (SNPs) was used on chemical sites to achieve controlled, electrically-actuated drug loading and releasing. Different neurotransmitters, including glutamate (Glu) and gamma-aminobutyric acid (GABA), were incorporated into the SNPs and electrically triggered to release repeatedly. An in vitro experiment was conducted to quantify the stimulated release profile by applying a sinusoidal voltage (0.5 V, 2 Hz). The flexible neural probe was implanted in the barrel cortex of the wild-type Sprague Dawley rats. As expected, due to their excitatory and inhibitory effects, Glu and GABA release caused a significant increase and decrease in neural activity, respectively, which was recorded by the recording microelectrodes. This novel flexible neural probe technology, combining on-demand chemical release and high-resolution electrophysiology recording, is an important addition to the neuroscience toolset used to dissect neural circuitry and investigate neural network connectivity.
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Affiliation(s)
| | - Bingchen Wu
- Bioengineering, University of Pittsburgh, Pittsburgh, PA 15260 USA
- Center for Neural Basis of Cognition, University of Pittsburgh and Carnegie Mellon University, Pittburgh, 15213 USA
- McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, 15219 USA
| | - Daniela D. Krahe
- Bioengineering, University of Pittsburgh, Pittsburgh, PA 15260 USA
| | - Zabir Ahmed
- Electrical and Computer Engineering, Carnegie Mellon University, Pittsburgh, PA 15213 USA
| | - Stephen Pupa
- Electrical and Computer Engineering, Carnegie Mellon University, Pittsburgh, PA 15213 USA
| | - Vishal Jain
- Electrical and Computer Engineering, Carnegie Mellon University, Pittsburgh, PA 15213 USA
| | - Xinyan Tracy Cui
- Bioengineering, University of Pittsburgh, Pittsburgh, PA 15260 USA
- Center for Neural Basis of Cognition, University of Pittsburgh and Carnegie Mellon University, Pittburgh, 15213 USA
- McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, 15219 USA
| | - Maysamreza Chamanzar
- Electrical and Computer Engineering, Carnegie Mellon University, Pittsburgh, PA 15213 USA
- Carnegie Mellon Neuroscience Institute, Carnegie Mellon University, Pittsburgh, 15213 USA
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Zhou C, Tian Y, Li G, Ye Y, Gao L, Li J, Liu Z, Su H, Lu Y, Li M, Zhou Z, Wei X, Qin L, Tao TH, Sun L. Through-polymer, via technology-enabled, flexible, lightweight, and integrated devices for implantable neural probes. MICROSYSTEMS & NANOENGINEERING 2024; 10:54. [PMID: 38654844 PMCID: PMC11035623 DOI: 10.1038/s41378-024-00691-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/28/2023] [Revised: 02/29/2024] [Accepted: 03/11/2024] [Indexed: 04/26/2024]
Abstract
In implantable electrophysiological recording systems, the headstage typically comprises neural probes that interface with brain tissue and integrated circuit chips for signal processing. While advancements in MEMS and CMOS technology have significantly improved these components, their interconnection still relies on conventional printed circuit boards and sophisticated adapters. This conventional approach adds considerable weight and volume to the package, especially for high channel count systems. To address this issue, we developed a through-polymer via (TPV) method inspired by the through-silicon via (TSV) technique in advanced three-dimensional packaging. This innovation enables the vertical integration of flexible probes, amplifier chips, and PCBs, realizing a flexible, lightweight, and integrated device (FLID). The total weight of the FLIDis only 25% that of its conventional counterparts relying on adapters, which significantly increased the activity levels of animals wearing the FLIDs to nearly match the levels of control animals without implants. Furthermore, by incorporating a platinum-iridium alloy as the top layer material for electrical contact, the FLID realizes exceptional electrical performance, enabling in vivo measurements of both local field potentials and individual neuron action potentials. These findings showcase the potential of FLIDs in scaling up implantable neural recording systems and mark a significant advancement in the field of neurotechnology.
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Grants
- This work was partially supported by the National Key R & D Program of China (Grant Nos. 2021ZD0201600, 2022YFF0706504, 2022ZD0209300, 2019YFA0905200, 2021YFC2501500, 2021YFF1200700, 2022ZD0212300), National Natural Science Foundation of China (Grant No. 61974154), Key Research Program of Frontier Sciences, CAS (Grant No. ZDBS-LY-JSC024), Shanghai Pilot Program for Basic Research-Chinese Academy of Science, Shanghai Branch (Grant No. JCYJ-SHFY-2022-01 and JCYJ-SHFY-2022-0xx), Shanghai Municipal Science and Technology Major Project (Grant No. 2021SHZDZX), CAS Pioneer Hundred Talents Program, Shanghai Pujiang Program (Grant Nos. 21PJ1415100, 19PJ1410900), the Science and Technology Commission Foundation of Shanghai (Nos. 21JM0010200 and 21142200300), Shanghai Rising-Star Program (Grant No. 22QA1410900), Shanghai Sailing Program (No. 22YF1454700), the Innovative Research Team of High-level Local Universities in Shanghai, the Jiangxi Province 03 Special Project and 5G Project (Grant No. 20212ABC03W07), Fund for Central Government in Guidance of Local Science and Technology Development (Grant No. 20201ZDE04013), Special Fund for Science and Technology Innovation Strategy of Guangdong Province (Grant Nos. 2021B0909060002, 2021B0909050004).
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Affiliation(s)
- Cunkai Zhou
- College of Electronics and Information Engineering, Shanghai University of Electric Power, Shanghai, China
- 2020 X-Lab, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai, China
| | - Ye Tian
- 2020 X-Lab, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai, China
- School of Graduate Study, University of Chinese Academy of Sciences, Beijing, China
| | - Gen Li
- 2020 X-Lab, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai, China
- School of Graduate Study, University of Chinese Academy of Sciences, Beijing, China
| | - Yifei Ye
- 2020 X-Lab, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai, China
| | - Lusha Gao
- 2020 X-Lab, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai, China
| | - Jiazhi Li
- 2020 X-Lab, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai, China
| | - Ziwei Liu
- 2020 X-Lab, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai, China
| | - Haoyang Su
- School of Graduate Study, University of Chinese Academy of Sciences, Beijing, China
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai, China
| | - Yunxiao Lu
- College of Electronics and Information Engineering, Shanghai University of Electric Power, Shanghai, China
- 2020 X-Lab, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai, China
| | - Meng Li
- School of Graduate Study, University of Chinese Academy of Sciences, Beijing, China
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai, China
| | - Zhitao Zhou
- School of Graduate Study, University of Chinese Academy of Sciences, Beijing, China
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai, China
| | - Xiaoling Wei
- School of Graduate Study, University of Chinese Academy of Sciences, Beijing, China
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai, China
| | - Lunming Qin
- College of Electronics and Information Engineering, Shanghai University of Electric Power, Shanghai, China
| | - Tiger H. Tao
- 2020 X-Lab, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai, China
- School of Graduate Study, University of Chinese Academy of Sciences, Beijing, China
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, China
- School of Physical Science and Technology, ShanghaiTech University, Shanghai, China
- Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China
- Neuroxess Co., Ltd. (Jiangxi), Nanchang, Jiangxi China
- Guangdong Institute of Intelligence Science and Technology, Hengqin, Zhuhai, Guangdong China
- Tianqiao and Chrissy Chen Institute for Translational Research, Shanghai, China
| | - Liuyang Sun
- College of Electronics and Information Engineering, Shanghai University of Electric Power, Shanghai, China
- 2020 X-Lab, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai, China
- School of Graduate Study, University of Chinese Academy of Sciences, Beijing, China
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai, China
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5
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Abu Shihada J, Jung M, Decke S, Koschinski L, Musall S, Rincón Montes V, Offenhäusser A. Highly Customizable 3D Microelectrode Arrays for In Vitro and In Vivo Neuronal Tissue Recordings. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024; 11:e2305944. [PMID: 38240370 PMCID: PMC10987114 DOI: 10.1002/advs.202305944] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Revised: 12/05/2023] [Indexed: 02/16/2024]
Abstract
Planar microelectrode arrays (MEAs) for - in vitro or in vivo - neuronal signal recordings lack the spatial resolution and sufficient signal-to-noise ratio (SNR) required for a detailed understanding of neural network function and synaptic plasticity. To overcome these limitations, a highly customizable three-dimensional (3D) printing process is used in combination with thin film technology and a self-aligned template-assisted electrochemical deposition process to fabricate 3D-printed-based MEAs on stiff or flexible substrates. Devices with design flexibility and physical robustness are shown for recording neural activity in different in vitro and in vivo applications, achieving high-aspect ratio 3D microelectrodes of up to 33:1. Here, MEAs successfully record neural activity in 3D neuronal cultures, retinal explants, and the cortex of living mice, thereby demonstrating the versatility of the 3D MEA while maintaining high-quality neural recordings. Customizable 3D MEAs provide unique opportunities to study neural activity under regular or various pathological conditions, both in vitro and in vivo, and contribute to the development of drug screening and neuromodulation systems that can accurately monitor the activity of large neural networks over time.
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Affiliation(s)
- J. Abu Shihada
- Institute of Biological Information Processing (IBI‐3) – BioelectronicsForschungszentrum52428JülichGermany
- RWTH Aachen University52062AachenGermany
| | - M. Jung
- Institute of Biological Information Processing (IBI‐3) – BioelectronicsForschungszentrum52428JülichGermany
- RWTH Aachen University52062AachenGermany
| | - S. Decke
- Institute of Biological Information Processing (IBI‐3) – BioelectronicsForschungszentrum52428JülichGermany
| | - L. Koschinski
- Institute of Biological Information Processing (IBI‐3) – BioelectronicsForschungszentrum52428JülichGermany
- RWTH Aachen University52062AachenGermany
- Helmholtz Nano Facility (HNF)Forschungszentrum Jülich52428JülichGermany
| | - S. Musall
- Institute of Biological Information Processing (IBI‐3) – BioelectronicsForschungszentrum52428JülichGermany
- RWTH Aachen University52062AachenGermany
- Faculty of MedicineInstitute of Experimental Epileptology and Cognition ResearchUniversity of Bonn53127BonnGermany
- University Hospital Bonn53127BonnGermany
| | - V. Rincón Montes
- Institute of Biological Information Processing (IBI‐3) – BioelectronicsForschungszentrum52428JülichGermany
| | - A. Offenhäusser
- Institute of Biological Information Processing (IBI‐3) – BioelectronicsForschungszentrum52428JülichGermany
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6
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Jia Q, Liu Y, Lv S, Wang Y, Jiao P, Xu W, Xu Z, Wang M, Cai X. Wireless closed-loop deep brain stimulation using microelectrode array probes. J Zhejiang Univ Sci B 2024:1-21. [PMID: 38423536 DOI: 10.1631/jzus.b2300400] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Accepted: 08/25/2023] [Indexed: 03/02/2024]
Abstract
Deep brain stimulation (DBS), including optical stimulation and electrical stimulation, has been demonstrated considerable value in exploring pathological brain activity and developing treatments for neural disorders. Advances in DBS microsystems based on implantable microelectrode array (MEA) probes have opened up new opportunities for closed-loop DBS (CL-DBS) in situ. This technology can be used to detect damaged brain circuits and test the therapeutic potential for modulating the output of these circuits in a variety of diseases simultaneously. Despite the success and rapid utilization of MEA probe-based CL-DBS microsystems, key challenges, including excessive wired communication, need to be urgently resolved. In this review, we considered recent advances in MEA probe-based wireless CL-DBS microsystems and outlined the major issues and promising prospects in this field. This technology has the potential to offer novel therapeutic options for psychiatric disorders in the future.
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Affiliation(s)
- Qianli Jia
- State Key Laboratory of Transducer Technology, Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing 100190, China
- School of Electronic, Electrical and Communication Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yaoyao Liu
- State Key Laboratory of Transducer Technology, Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing 100190, China
- School of Electronic, Electrical and Communication Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Shiya Lv
- State Key Laboratory of Transducer Technology, Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing 100190, China
- School of Electronic, Electrical and Communication Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yiding Wang
- State Key Laboratory of Transducer Technology, Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing 100190, China
- School of Electronic, Electrical and Communication Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Peiyao Jiao
- State Key Laboratory of Transducer Technology, Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing 100190, China
- School of Electronic, Electrical and Communication Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Wei Xu
- State Key Laboratory of Transducer Technology, Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing 100190, China
- School of Electronic, Electrical and Communication Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zhaojie Xu
- State Key Laboratory of Transducer Technology, Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing 100190, China
- School of Electronic, Electrical and Communication Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Mixia Wang
- State Key Laboratory of Transducer Technology, Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing 100190, China.
- School of Electronic, Electrical and Communication Engineering, University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Xinxia Cai
- State Key Laboratory of Transducer Technology, Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing 100190, China. ,
- School of Electronic, Electrical and Communication Engineering, University of Chinese Academy of Sciences, Beijing 100049, China. ,
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7
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Boulingre M, Portillo-Lara R, Green RA. Biohybrid neural interfaces: improving the biological integration of neural implants. Chem Commun (Camb) 2023; 59:14745-14758. [PMID: 37991846 PMCID: PMC10720954 DOI: 10.1039/d3cc05006h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Accepted: 11/10/2023] [Indexed: 11/24/2023]
Abstract
Implantable neural interfaces (NIs) have emerged in the clinic as outstanding tools for the management of a variety of neurological conditions caused by trauma or disease. However, the foreign body reaction triggered upon implantation remains one of the major challenges hindering the safety and longevity of NIs. The integration of tools and principles from biomaterial design and tissue engineering has been investigated as a promising strategy to develop NIs with enhanced functionality and performance. In this Feature Article, we highlight the main bioengineering approaches for the development of biohybrid NIs with an emphasis on relevant device design criteria. Technical and scientific challenges associated with the fabrication and functional assessment of technologies composed of both artificial and biological components are discussed. Lastly, we provide future perspectives related to engineering, regulatory, and neuroethical challenges to be addressed towards the realisation of the promise of biohybrid neurotechnology.
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Affiliation(s)
- Marjolaine Boulingre
- Department of Bioengineering, Imperial College London, South Kensington, London, SW7 2AZ, UK
| | - Roberto Portillo-Lara
- Department of Bioengineering, Imperial College London, South Kensington, London, SW7 2AZ, UK
| | - Rylie A Green
- Department of Bioengineering, Imperial College London, South Kensington, London, SW7 2AZ, UK
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8
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Perna A, Angotzi GN, Berdondini L, Ribeiro JF. Advancing the interfacing performances of chronically implantable neural probes in the era of CMOS neuroelectronics. Front Neurosci 2023; 17:1275908. [PMID: 38027514 PMCID: PMC10644322 DOI: 10.3389/fnins.2023.1275908] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Accepted: 10/10/2023] [Indexed: 12/01/2023] Open
Abstract
Tissue penetrating microelectrode neural probes can record electrophysiological brain signals at resolutions down to single neurons, making them invaluable tools for neuroscience research and Brain-Computer-Interfaces (BCIs). The known gradual decrease of their electrical interfacing performances in chronic settings, however, remains a major challenge. A key factor leading to such decay is Foreign Body Reaction (FBR), which is the cascade of biological responses that occurs in the brain in the presence of a tissue damaging artificial device. Interestingly, the recent adoption of Complementary Metal Oxide Semiconductor (CMOS) technology to realize implantable neural probes capable of monitoring hundreds to thousands of neurons simultaneously, may open new opportunities to face the FBR challenge. Indeed, this shift from passive Micro Electro-Mechanical Systems (MEMS) to active CMOS neural probe technologies creates important, yet unexplored, opportunities to tune probe features such as the mechanical properties of the probe, its layout, size, and surface physicochemical properties, to minimize tissue damage and consequently FBR. Here, we will first review relevant literature on FBR to provide a better understanding of the processes and sources underlying this tissue response. Methods to assess FBR will be described, including conventional approaches based on the imaging of biomarkers, and more recent transcriptomics technologies. Then, we will consider emerging opportunities offered by the features of CMOS probes. Finally, we will describe a prototypical neural probe that may meet the needs for advancing clinical BCIs, and we propose axial insertion force as a potential metric to assess the influence of probe features on acute tissue damage and to control the implantation procedure to minimize iatrogenic injury and subsequent FBR.
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Affiliation(s)
- Alberto Perna
- Microtechnology for Neuroelectronics Lab, Fondazione Istituto Italiano di Tecnologia, Neuroscience and Brain Technologies, Genova, Italy
- The Open University Affiliated Research Centre at Istituto Italiano di Tecnologia (ARC@IIT), Istituto Italiano di Tecnologia, Genova, Italy
| | - Gian Nicola Angotzi
- Microtechnology for Neuroelectronics Lab, Fondazione Istituto Italiano di Tecnologia, Neuroscience and Brain Technologies, Genova, Italy
| | - Luca Berdondini
- Microtechnology for Neuroelectronics Lab, Fondazione Istituto Italiano di Tecnologia, Neuroscience and Brain Technologies, Genova, Italy
| | - João Filipe Ribeiro
- Microtechnology for Neuroelectronics Lab, Fondazione Istituto Italiano di Tecnologia, Neuroscience and Brain Technologies, Genova, Italy
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9
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Zhou Y, Yang H, Wang X, Yang H, Sun K, Zhou Z, Sun L, Zhao J, Tao TH, Wei X. A mosquito mouthpart-like bionic neural probe. MICROSYSTEMS & NANOENGINEERING 2023; 9:88. [PMID: 37448967 PMCID: PMC10336119 DOI: 10.1038/s41378-023-00565-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/11/2023] [Revised: 05/05/2023] [Accepted: 05/29/2023] [Indexed: 07/18/2023]
Abstract
Advancements in microscale electrode technology have revolutionized the field of neuroscience and clinical applications by offering high temporal and spatial resolution of recording and stimulation. Flexible neural probes, with their mechanical compliance to brain tissue, have been shown to be superior to rigid devices in terms of stability and longevity in chronic recordings. Shuttle devices are commonly used to assist flexible probe implantation; however, the protective membrane of the brain still makes penetration difficult. Hidden damage to brain vessels during implantation is a significant risk. Inspired by the anatomy of the mosquito mouthparts, we present a biomimetic neuroprobe system that integrates high-sensitivity sensors with a high-fidelity multichannel flexible electrode array. This customizable system achieves distributed and minimally invasive implantation across brain regions. Most importantly, the system's nonvisual monitoring capability provides an early warning detection for intracranial soft tissues, such as vessels, reducing the potential for injury during implantation. The neural probe system demonstrates exceptional sensitivity and adaptability to environmental stimuli, as well as outstanding performance in postoperative and chronic recordings. These findings suggest that our biomimetic neural-probe device offers promising potential for future applications in neuroscience and brain-machine interfaces. A mosquito mouthpart-like bionic neural probe consisting of a highly sensitive tactile sensor module, a flexible microelectrode array, and implanted modules that mimic the structure of mosquito mouthparts. The system enables distributed implantation of electrode arrays across multiple brain regions while making the implantation minimally invasive and avoiding additional dural removal. The tactile sensor array can monitor the implantation process to achieve early warning of vascular damage. The excellent postoperative short-term recording performance and long-term neural activity tracking ability demonstrate that the system is a promising tool in the field of brain-computer interfaces.
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Affiliation(s)
- Yu Zhou
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 200050 Shanghai, China
- School of Graduate Study, University of Chinese Academy of Sciences, 100049 Beijing, China
| | - Huiran Yang
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 200050 Shanghai, China
- School of Graduate Study, University of Chinese Academy of Sciences, 100049 Beijing, China
| | - Xueying Wang
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 200050 Shanghai, China
- School of Graduate Study, University of Chinese Academy of Sciences, 100049 Beijing, China
| | - Heng Yang
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 200050 Shanghai, China
- School of Graduate Study, University of Chinese Academy of Sciences, 100049 Beijing, China
| | - Ke Sun
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 200050 Shanghai, China
- School of Graduate Study, University of Chinese Academy of Sciences, 100049 Beijing, China
| | - Zhitao Zhou
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 200050 Shanghai, China
- School of Graduate Study, University of Chinese Academy of Sciences, 100049 Beijing, China
| | - Liuyang Sun
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 200050 Shanghai, China
- School of Graduate Study, University of Chinese Academy of Sciences, 100049 Beijing, China
- 2020 X-Lab, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 200050 Shanghai, China
| | - Jianlong Zhao
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 200050 Shanghai, China
- School of Graduate Study, University of Chinese Academy of Sciences, 100049 Beijing, China
| | - Tiger H. Tao
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 200050 Shanghai, China
- School of Graduate Study, University of Chinese Academy of Sciences, 100049 Beijing, China
- 2020 X-Lab, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 200050 Shanghai, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, 100049 Beijing, China
- Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, 200031 Shanghai, China
- Neuroxess Co., Ltd. (Jiangxi), 330029 Nanchang, Jiangxi China
- Guangdong Institute of Intelligence Science and Technology, Hengqin, 519031 Zhuhai, Guangdong China
- Tianqiao and Chrissy Chen Institute for Translational Research, Shanghai, China
| | - Xiaoling Wei
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 200050 Shanghai, China
- School of Graduate Study, University of Chinese Academy of Sciences, 100049 Beijing, China
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10
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Amirghasemi F, Soleimani A, Bawarith S, Tabassum A, Morrel A, Mousavi MPS. FAST (Flexible Acetylcholine Sensing Thread): Real-Time Detection of Acetylcholine with a Flexible Solid-Contact Potentiometric Sensor. Bioengineering (Basel) 2023; 10:655. [PMID: 37370586 DOI: 10.3390/bioengineering10060655] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Revised: 05/22/2023] [Accepted: 05/24/2023] [Indexed: 06/29/2023] Open
Abstract
Acetylcholine (ACh) is involved in memory and learning and has implications in neurodegenerative diseases; it is therefore important to study the dynamics of ACh in the brain. This work creates a flexible solid-contact potentiometric sensor for in vitro and in vivo recording of ACh in the brain and tissue homogenate. We fabricate this sensor using a 250 μm diameter cotton yarn coated with a flexible conductive ink and an ACh sensing membrane that contains a calix[4]arene ionophore. The exposed ion-to-electron transducer was sealed with a 2.5 μm thick Parylene C coating to maintain the flexibility of the sensor. The resulting diameter of the flexible ACh sensing thread (FAST) was 400 μm. The FAST showed a linear response range from 1.0 μM to 10.0 mM in deionized water, with a near-Nernstian slope of 56.11 mV/decade and a limit of detection of 2.6 μM. In artificial cerebrospinal fluid, the limit of detection increased to 20 μM due to the background signal of ionic content of the cerebrospinal fluid. The FAST showed a signal stability of 226 μV/h over 24 h. We show that FAST can measure ACh dynamics in sheep brain tissue and sheep brain homogenate after ACh spiking. FAST is the first flexible electrochemical sensor for monitoring ACh dynamics in the brain.
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Affiliation(s)
- Farbod Amirghasemi
- Alfred E. Mann Department of Biomedical Engineering, Viterbi School of Engineering, University of Southern California, Los Angeles, CA 90089, USA
| | - Ali Soleimani
- Alfred E. Mann Department of Biomedical Engineering, Viterbi School of Engineering, University of Southern California, Los Angeles, CA 90089, USA
| | - Shahd Bawarith
- Alfred E. Mann Department of Biomedical Engineering, Viterbi School of Engineering, University of Southern California, Los Angeles, CA 90089, USA
| | - Asna Tabassum
- Alfred E. Mann Department of Biomedical Engineering, Viterbi School of Engineering, University of Southern California, Los Angeles, CA 90089, USA
| | - Alayne Morrel
- Alfred E. Mann Department of Biomedical Engineering, Viterbi School of Engineering, University of Southern California, Los Angeles, CA 90089, USA
| | - Maral P S Mousavi
- Alfred E. Mann Department of Biomedical Engineering, Viterbi School of Engineering, University of Southern California, Los Angeles, CA 90089, USA
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11
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Song S, Fallegger F, Trouillet A, Kim K, Lacour SP. Deployment of an electrocorticography system with a soft robotic actuator. Sci Robot 2023; 8:eadd1002. [PMID: 37163609 DOI: 10.1126/scirobotics.add1002] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Electrocorticography (ECoG) is a minimally invasive approach frequently used clinically to map epileptogenic regions of the brain and facilitate lesion resection surgery and increasingly explored in brain-machine interface applications. Current devices display limitations that require trade-offs among cortical surface coverage, spatial electrode resolution, aesthetic, and risk consequences and often limit the use of the mapping technology to the operating room. In this work, we report on a scalable technique for the fabrication of large-area soft robotic electrode arrays and their deployment on the cortex through a square-centimeter burr hole using a pressure-driven actuation mechanism called eversion. The deployable system consists of up to six prefolded soft legs, and it is placed subdurally on the cortex using an aqueous pressurized solution and secured to the pedestal on the rim of the small craniotomy. Each leg contains soft, microfabricated electrodes and strain sensors for real-time deployment monitoring. In a proof-of-concept acute surgery, a soft robotic electrode array was successfully deployed on the cortex of a minipig to record sensory cortical activity. This soft robotic neurotechnology opens promising avenues for minimally invasive cortical surgery and applications related to neurological disorders such as motor and sensory deficits.
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Affiliation(s)
- Sukho Song
- Laboratory for Soft Bioelectronic Interfaces, Neuro-X Institute, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1202 Geneva, Switzerland
- Laboratory of Sustainability Robotics, Swiss Federal Laboratories for Materials Science and Technology (Empa), 8600 Dübendorf, Switzerland
| | - Florian Fallegger
- Laboratory for Soft Bioelectronic Interfaces, Neuro-X Institute, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1202 Geneva, Switzerland
| | - Alix Trouillet
- Laboratory for Soft Bioelectronic Interfaces, Neuro-X Institute, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1202 Geneva, Switzerland
| | - Kyungjin Kim
- Laboratory for Soft Bioelectronic Interfaces, Neuro-X Institute, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1202 Geneva, Switzerland
- Department of Mechanical Engineering, University of Connecticut, Storrs, CT 06269, USA
| | - Stéphanie P Lacour
- Laboratory for Soft Bioelectronic Interfaces, Neuro-X Institute, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1202 Geneva, Switzerland
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12
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Shur M, Akouissi O, Rizzo O, Colin DJ, Kolinski JM, Lacour SP. Revealing the complexity of ultra-soft hydrogel re-swelling inside the brain. Biomaterials 2023; 294:122024. [PMID: 36716587 DOI: 10.1016/j.biomaterials.2023.122024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Revised: 12/12/2022] [Accepted: 01/20/2023] [Indexed: 01/27/2023]
Abstract
The brain is an ultra-soft viscoelastic matrix. Sub-kPa hydrogels match the brain's mechanical properties but are challenging to manipulate in an implantable format. We propose a simple fabrication and processing sequence, consisting of de-hydration, patterning, implantation, and re-hydration steps, to deliver brain-like hydrogel implants into the nervous tissue. We monitored in real-time the ultra-soft hydrogel re-swelling kinetics in vivo using microcomputed tomography, achieved by embedding gold nanoparticles inside the hydrogel for contrast enhancement. We found that re-swelling in vivo strongly depends on the implant geometry and water availability at the hydrogel-tissue interface. Buckling of the implant inside the brain occurs when the soft implant is tethered to the cranium. Finite-element and analytical models reveal how the shank geometry, modulus and anchoring govern in vivo buckling. Taken together, these considerations on re-swelling kinetics of hydrogel constructs, implant geometry and soft implant-tissue mechanical interplay can guide the engineering of biomimetic brain implants.
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Affiliation(s)
- Michael Shur
- Bertarelli Foundation Chair in Neuroprosthetic Technology, Laboratory for Soft Bioelectronic Interfaces, Neuro-X Institute, École Polytechnique Fedérale de Lausanne (EPFL), 1202, Geneva, Switzerland
| | - Outman Akouissi
- Bertarelli Foundation Chair in Neuroprosthetic Technology, Laboratory for Soft Bioelectronic Interfaces, Neuro-X Institute, École Polytechnique Fedérale de Lausanne (EPFL), 1202, Geneva, Switzerland; Bertarelli Foundation Chair in Translational Neuroengineering, Institute of Bioengineering, Center for Neuroprosthetics, École Polytechnique Fédérale de Lausanne (EPFL), 1202, Geneva, Switzerland
| | - Olivier Rizzo
- Bertarelli Foundation Chair in Neuroprosthetic Technology, Laboratory for Soft Bioelectronic Interfaces, Neuro-X Institute, École Polytechnique Fedérale de Lausanne (EPFL), 1202, Geneva, Switzerland
| | - Didier J Colin
- Preclinical Imaging Platform, Faculty of Medicine, University of Geneva, 1211, Geneva, Switzerland
| | - John M Kolinski
- Laboratory of Engineering Mechanics of Soft Interfaces, Institute of Mechanical Engineering, École Polytechnique Fédérale de Lausanne (EPFL), 1015, Lausanne, Switzerland
| | - Stéphanie P Lacour
- Bertarelli Foundation Chair in Neuroprosthetic Technology, Laboratory for Soft Bioelectronic Interfaces, Neuro-X Institute, École Polytechnique Fedérale de Lausanne (EPFL), 1202, Geneva, Switzerland.
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13
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Kumosa LS. Commonly Overlooked Factors in Biocompatibility Studies of Neural Implants. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2023; 10:e2205095. [PMID: 36596702 PMCID: PMC9951391 DOI: 10.1002/advs.202205095] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Revised: 11/16/2022] [Indexed: 06/17/2023]
Abstract
Biocompatibility of cutting-edge neural implants, surgical tools and techniques, and therapeutic technologies is a challenging concept that can be easily misjudged. For example, neural interfaces are routinely gauged on how effectively they determine active neurons near their recording sites. Tissue integration and toxicity of neural interfaces are frequently assessed histologically in animal models to determine tissue morphological and cellular changes in response to surgical implantation and chronic presence. A disconnect between histological and efficacious biocompatibility exists, however, as neuronal numbers frequently observed near electrodes do not match recorded neuronal spiking activity. The downstream effects of the myriad surgical and experimental factors involved in such studies are rarely examined when deciding whether a technology or surgical process is biocompatible. Such surgical factors as anesthesia, temperature excursions, bleed incidence, mechanical forces generated, and metabolic conditions are known to have strong systemic and thus local cellular and extracellular consequences. Many tissue markers are extremely sensitive to the physiological state of cells and tissues, thus significantly impacting histological accuracy. This review aims to shed light on commonly overlooked factors that can have a strong impact on the assessment of neural biocompatibility and to address the mismatch between results stemming from functional and histological methods.
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Affiliation(s)
- Lucas S. Kumosa
- Neuronano Research CenterDepartment of Experimental Medical ScienceMedical FacultyLund UniversityMedicon Village, Byggnad 404 A2, Scheelevägen 8Lund223 81Sweden
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14
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Merken L, Schelles M, Ceyssens F, Kraft M, Janssen P. Thin flexible arrays for long-term multi-electrode recordings in macaque primary visual cortex. J Neural Eng 2022; 19. [PMID: 36215972 DOI: 10.1088/1741-2552/ac98e2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Accepted: 10/10/2022] [Indexed: 01/11/2023]
Abstract
Objective.Basic, translational and clinical neuroscience are increasingly focusing on large-scale invasive recordings of neuronal activity. However, in large animals such as nonhuman primates and humans-in which the larger brain size with sulci and gyri imposes additional challenges compared to rodents, there is a huge unmet need to record from hundreds of neurons simultaneously anywhere in the brain for long periods of time. Here, we tested the electrical and mechanical properties of thin, flexible multi-electrode arrays (MEAs) inserted into the primary visual cortex of two macaque monkeys, and assessed their magnetic resonance imaging (MRI) compatibility and their capacity to record extracellular activity over a period of 1 year.Approach.To allow insertion of the floating arrays into the visual cortex, the 20 by 100µm2shafts were temporarily strengthened by means of a resorbable poly(lactic-co-glycolic acid) coating.Main results. After manual insertion of the arrays, theex vivoandin vivoMRI compatibility of the arrays proved to be excellent. We recorded clear single-unit activity from up to 50% of the electrodes, and multi-unit activity (MUA) on 60%-100% of the electrodes, which allowed detailed measurements of the receptive fields and the orientation selectivity of the neurons. Even 1 year after insertion, we obtained significant MUA responses on 70%-100% of the electrodes, while the receptive fields remained remarkably stable over the entire recording period.Significance.Thus, the thin and flexible MEAs we tested offer several crucial advantages compared to existing arrays, most notably in terms of brain tissue compliance, scalability, and brain coverage. Future brain-machine interface applications in humans may strongly benefit from this new generation of chronically implanted MEAs.
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Affiliation(s)
- Lara Merken
- Laboratory for Neuro- and Psychophysiology, KU Leuven, Leuven 3000, Belgium.,Leuven Brain Institute, KU Leuven, Leuven 3000, Belgium
| | - Maarten Schelles
- Micro- and Nanosystems (MNS), Electrical Engineering Department (ESAT), KU Leuven, Leuven 3000, Belgium.,ReVision Implant NV, Haasrode 3053, Belgium
| | | | - Michael Kraft
- Micro- and Nanosystems (MNS), Electrical Engineering Department (ESAT), KU Leuven, Leuven 3000, Belgium.,Leuven Institute for Micro- and Nanotechnology (LIMNI), Leuven 3000, Belgium
| | - Peter Janssen
- Laboratory for Neuro- and Psychophysiology, KU Leuven, Leuven 3000, Belgium.,Leuven Brain Institute, KU Leuven, Leuven 3000, Belgium
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15
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Luo J, Xue N, Chen J. A Review: Research Progress of Neural Probes for Brain Research and Brain-Computer Interface. BIOSENSORS 2022; 12:bios12121167. [PMID: 36551135 PMCID: PMC9775442 DOI: 10.3390/bios12121167] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Revised: 12/07/2022] [Accepted: 12/13/2022] [Indexed: 06/01/2023]
Abstract
Neural probes, as an invasive physiological tool at the mesoscopic scale, can decipher the code of brain connections and communications from the cellular or even molecular level, and realize information fusion between the human body and external machines. In addition to traditional electrodes, two new types of neural probes have been developed in recent years: optoprobes based on optogenetics and magnetrodes that record neural magnetic signals. In this review, we give a comprehensive overview of these three kinds of neural probes. We firstly discuss the development of microelectrodes and strategies for their flexibility, which is mainly represented by the selection of flexible substrates and new electrode materials. Subsequently, the concept of optogenetics is introduced, followed by the review of several novel structures of optoprobes, which are divided into multifunctional optoprobes integrated with microfluidic channels, artifact-free optoprobes, three-dimensional drivable optoprobes, and flexible optoprobes. At last, we introduce the fundamental perspectives of magnetoresistive (MR) sensors and then review the research progress of magnetrodes based on it.
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Affiliation(s)
- Jiahui Luo
- State Key Laboratory of Transducer Technology, Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing 100190, China
- School of Electronic, Electrical and Communication Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Ning Xue
- State Key Laboratory of Transducer Technology, Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing 100190, China
- School of Electronic, Electrical and Communication Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jiamin Chen
- State Key Laboratory of Transducer Technology, Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing 100190, China
- School of Electronic, Electrical and Communication Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
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16
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Freitas JR, Pimenta S, Santos DJ, Esteves B, Gomes NM, Correia JH. Flexible Neural Probe Fabrication Enhanced with a Low-Temperature Cured Polyimide and Platinum Electrodeposition. SENSORS (BASEL, SWITZERLAND) 2022; 22:9674. [PMID: 36560042 PMCID: PMC9783888 DOI: 10.3390/s22249674] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Revised: 11/30/2022] [Accepted: 12/08/2022] [Indexed: 06/17/2023]
Abstract
Polyimide is an emerging and very interesting material for substrate and passivation of neural probes. However, the standard curing temperature of polyimide (350 °C) is critical for the microelectrodes and contact pads of the neural probe, due to the thermal oxidation of the metals during the passivation process of the neural probe. Here, the fabrication process of a flexible neural probe, enhanced with a photosensitive and low-temperature cured polyimide, is presented. Annealing tests were performed with metallic films deposited on polyimide, which led to the reduction of the curing temperature to 250 °C, with no significant irregularities in the metallic sample annealed at that temperature and an effective polyimide curing. The use of a lower curing temperature reduces the thermal oxidation of the metals during the polyimide curing process to passivate the neural probe. Additionally, in this fabrication process, the microelectrodes of the neural probe were coated with electrodeposited platinum (Pt), only after the passivation process, and its electrochemical performance was accessed. At 1 kHz, the impedance of the microelectrodes before Pt electrodeposition was approximately 1.2 MΩ, and after Pt electrodeposition, it was approximately 350 kΩ. Pt electrodeposition changed the equivalent circuit of the microelectrodes and reduced their impedance, which will be crucial for future in-vivo tests to acquire the electrical activity of the neurons with the fabricated neural probe.
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Affiliation(s)
- João R. Freitas
- CMEMS—UMinho, University of Minho, 4800-058 Guimarães, Portugal
- LABBELS—Associate Laboratory, Braga/Guimarães, Portugal
| | - Sara Pimenta
- CMEMS—UMinho, University of Minho, 4800-058 Guimarães, Portugal
- LABBELS—Associate Laboratory, Braga/Guimarães, Portugal
| | - Diogo J. Santos
- CMEMS—UMinho, University of Minho, 4800-058 Guimarães, Portugal
- LABBELS—Associate Laboratory, Braga/Guimarães, Portugal
| | - Bruno Esteves
- CMEMS—UMinho, University of Minho, 4800-058 Guimarães, Portugal
- LABBELS—Associate Laboratory, Braga/Guimarães, Portugal
| | - Nuno M. Gomes
- CMEMS—UMinho, University of Minho, 4800-058 Guimarães, Portugal
- LABBELS—Associate Laboratory, Braga/Guimarães, Portugal
| | - José H. Correia
- CMEMS—UMinho, University of Minho, 4800-058 Guimarães, Portugal
- LABBELS—Associate Laboratory, Braga/Guimarães, Portugal
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17
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Erofeev A, Antifeev I, Bolshakova A, Bezprozvanny I, Vlasova O. In Vivo Penetrating Microelectrodes for Brain Electrophysiology. SENSORS (BASEL, SWITZERLAND) 2022; 22:s22239085. [PMID: 36501805 PMCID: PMC9735502 DOI: 10.3390/s22239085] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Revised: 11/14/2022] [Accepted: 11/22/2022] [Indexed: 05/13/2023]
Abstract
In recent decades, microelectrodes have been widely used in neuroscience to understand the mechanisms behind brain functions, as well as the relationship between neural activity and behavior, perception and cognition. However, the recording of neuronal activity over a long period of time is limited for various reasons. In this review, we briefly consider the types of penetrating chronic microelectrodes, as well as the conductive and insulating materials for microelectrode manufacturing. Additionally, we consider the effects of penetrating microelectrode implantation on brain tissue. In conclusion, we review recent advances in the field of in vivo microelectrodes.
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Affiliation(s)
- Alexander Erofeev
- Laboratory of Molecular Neurodegeneration, Graduate School of Biomedical Systems and Technologies, Institute of Biomedical Systems and Biotechnology, Peter the Great St. Petersburg Polytechnic University, 195251 Saint Petersburg, Russia
- Correspondence: (A.E.); (O.V.)
| | - Ivan Antifeev
- Laboratory of Methods and Instruments for Genetic and Immunoassay Analysis, Institute for Analytical Instrumentation of the Russian Academy of Sciences, 198095 Saint Petersburg, Russia
| | - Anastasia Bolshakova
- Laboratory of Molecular Neurodegeneration, Graduate School of Biomedical Systems and Technologies, Institute of Biomedical Systems and Biotechnology, Peter the Great St. Petersburg Polytechnic University, 195251 Saint Petersburg, Russia
| | - Ilya Bezprozvanny
- Laboratory of Molecular Neurodegeneration, Graduate School of Biomedical Systems and Technologies, Institute of Biomedical Systems and Biotechnology, Peter the Great St. Petersburg Polytechnic University, 195251 Saint Petersburg, Russia
- Department of Physiology, University of Texas Southwestern Medical Center at Dallas, Dallas, TX 75390, USA
| | - Olga Vlasova
- Laboratory of Molecular Neurodegeneration, Graduate School of Biomedical Systems and Technologies, Institute of Biomedical Systems and Biotechnology, Peter the Great St. Petersburg Polytechnic University, 195251 Saint Petersburg, Russia
- Correspondence: (A.E.); (O.V.)
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18
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Störi MJ, Oluwasanya PW, Proctor CM. Diffusive drug delivery in the brain extracellular space from a cellular scale microtube. MRS COMMUNICATIONS 2022; 12:654-661. [PMID: 36312901 PMCID: PMC9596563 DOI: 10.1557/s43579-022-00247-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Accepted: 08/18/2022] [Indexed: 06/16/2023]
Abstract
UNLABELLED The effectiveness of state-of-the-art systemic treatments for neurological disorders is hampered not only by the difficulty in crossing the blood brain barrier but also off-target drug interactions. In this study, a delivery method is simulated for a novel U-shaped microtube locally infusing drugs directly into the extracellular space of the brain and relying on diffusion as a transport mechanism. The influence of flow rate, drug properties and device geometry are investigated. It is anticipated that these findings will accelerate progress on both developmental and applied drug delivery and materials research. SUPPLEMENTARY INFORMATION The online version contains supplementary material available at 10.1557/s43579-022-00247-9.
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Affiliation(s)
- Marie-Joe Störi
- Engineering Department, University of Cambridge, Cambridge, UK
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19
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Gurke J, Naegele TE, Hilton S, Pezone R, Curto VF, Barone DG, List-Kratochvil EJW, Carnicer-Lombarte A, Malliaras GG. Hybrid fabrication of multimodal intracranial implants for electrophysiology and local drug delivery. MATERIALS HORIZONS 2022; 9:1727-1734. [PMID: 35474130 PMCID: PMC9169700 DOI: 10.1039/d1mh01855h] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Accepted: 04/21/2022] [Indexed: 05/31/2023]
Abstract
New fabrication approaches for mechanically flexible implants hold the key to advancing the applications of neuroengineering in fundamental neuroscience and clinic. By combining the high precision of thin film microfabrication with the versatility of additive manufacturing, we demonstrate a straight-forward approach for the prototyping of intracranial implants with electrode arrays and microfluidic channels. We show that the implant can modulate neuronal activity in the hippocampus through localized drug delivery, while simultaneously recording brain activity by its electrodes. Moreover, good implant stability and minimal tissue response are seen one-week post-implantation. Our work shows the potential of hybrid fabrication combining different manufacturing techniques in neurotechnology and paves the way for a new approach to the development of multimodal implants.
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Affiliation(s)
- Johannes Gurke
- University of Cambridge, Electrical Engineering Division, 9 JJ Thomson Ave, Cambridge, CB3 0FA, UK.
| | - Tobias E Naegele
- University of Cambridge, Electrical Engineering Division, 9 JJ Thomson Ave, Cambridge, CB3 0FA, UK.
| | - Sam Hilton
- University of Cambridge, Electrical Engineering Division, 9 JJ Thomson Ave, Cambridge, CB3 0FA, UK.
| | - Roberto Pezone
- University of Cambridge, Electrical Engineering Division, 9 JJ Thomson Ave, Cambridge, CB3 0FA, UK.
| | - Vincenzo F Curto
- University of Cambridge, Electrical Engineering Division, 9 JJ Thomson Ave, Cambridge, CB3 0FA, UK.
| | - Damiano G Barone
- University of Cambridge, Electrical Engineering Division, 9 JJ Thomson Ave, Cambridge, CB3 0FA, UK.
- University of Cambridge, School of Clinical Medicine, Department of Clinical Neurosciences, Cambridge Biomedical Campus, Cambridge CB2 0QQ, UK
| | - Emil J W List-Kratochvil
- Humboldt-Universität zu Berlin, Department of Chemistry and of Physics and IRIS Adlershof, Hybrid Devices Group, Zum Großen Windkanal 2, 12489 Berlin, Germany
- Helmholtz-Zentrum für Materialien und Energie GmbH, Hahn-Meitner-Platz 1, 14109, Berlin, Germany
| | | | - George G Malliaras
- University of Cambridge, Electrical Engineering Division, 9 JJ Thomson Ave, Cambridge, CB3 0FA, UK.
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20
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Bhaskara S, Sakorikar T, Chatterjee S, Shabari Girishan K, Pandya HJ. Recent advancements in Micro-engineered devices for surface and deep brain animal studies: A review. SENSING AND BIO-SENSING RESEARCH 2022. [DOI: 10.1016/j.sbsr.2022.100483] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
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21
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Tringides CM, Mooney DJ. Materials for Implantable Surface Electrode Arrays: Current Status and Future Directions. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2022; 34:e2107207. [PMID: 34716730 DOI: 10.1002/adma.202107207] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Revised: 10/26/2021] [Indexed: 06/13/2023]
Abstract
Surface electrode arrays are mainly fabricated from rigid or elastic materials, and precisely manipulated ductile metal films, which offer limited stretchability. However, the living tissues to which they are applied are nonlinear viscoelastic materials, which can undergo significant mechanical deformation in dynamic biological environments. Further, the same arrays and compositions are often repurposed for vastly different tissues rather than optimizing the materials and mechanical properties of the implant for the target application. By first characterizing the desired biological environment, and then designing a technology for a particular organ, surface electrode arrays may be more conformable, and offer better interfaces to tissues while causing less damage. Here, the various materials used in each component of a surface electrode array are first reviewed, and then electrically active implants in three specific biological systems, the nervous system, the muscular system, and skin, are described. Finally, the fabrication of next-generation surface arrays that overcome current limitations is discussed.
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Affiliation(s)
- Christina M Tringides
- Harvard Program in Biophysics, Harvard University, Cambridge, MA, 02138, USA
- Harvard-MIT Division in Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Cambridge, MA, 02138, USA
| | - David J Mooney
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Cambridge, MA, 02138, USA
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, 02138, USA
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22
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Kiang L, Woodington B, Carnicer-Lombarte A, Malliaras G, Barone DG. Spinal cord bioelectronic interfaces: opportunities in neural recording and clinical challenges. J Neural Eng 2022; 19. [PMID: 35320780 DOI: 10.1088/1741-2552/ac605f] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Accepted: 03/23/2022] [Indexed: 11/11/2022]
Abstract
Bioelectronic stimulation of the spinal cord has demonstrated significant progress in restoration of motor function in spinal cord injury (SCI). The proximal, uninjured spinal cord presents a viable target for the recording and generation of control signals to drive targeted stimulation. Signals have been directly recorded from the spinal cord in behaving animals and correlated with limb kinematics. Advances in flexible materials, electrode impedance and signal analysis will allow SCR to be used in next-generation neuroprosthetics. In this review, we summarize the technological advances enabling progress in SCR and describe systematically the clinical challenges facing spinal cord bioelectronic interfaces and potential solutions, from device manufacture, surgical implantation to chronic effects of foreign body reaction and stress-strain mismatches between electrodes and neural tissue. Finally, we establish our vision of bi-directional closed-loop spinal cord bioelectronic bypass interfaces that enable the communication of disrupted sensory signals and restoration of motor function in SCI.
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Affiliation(s)
- Lei Kiang
- Orthopaedic Surgery, Singapore General Hospital, Outram Road, Singapore, Singapore, 169608, SINGAPORE
| | - Ben Woodington
- Department of Engineering, University of Cambridge, Electrical Engineering Division, 9 JJ Thomson Ave, Cambridge, Cambridge, CB2 1TN, UNITED KINGDOM OF GREAT BRITAIN AND NORTHERN IRELAND
| | - Alejandro Carnicer-Lombarte
- Clinical Neurosciences, University of Cambridge, Bioelectronics Laboratory, Cambridge, CB2 0PY, UNITED KINGDOM OF GREAT BRITAIN AND NORTHERN IRELAND
| | - George Malliaras
- University of Cambridge, University of Cambridge, Cambridge, CB2 1TN, UNITED KINGDOM OF GREAT BRITAIN AND NORTHERN IRELAND
| | - Damiano G Barone
- Department of Engineering, University of Cambridge, Electrical Engineering Division, 9 JJ Thomson Ave, Cambridge, Cambridge, Cambridgeshire, CB2 1TN, UNITED KINGDOM OF GREAT BRITAIN AND NORTHERN IRELAND
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23
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PtNPs/Short MWCNT-PEDOT: PSS-Modified Microelectrode Array to Detect Neuronal Firing Patterns in the Dorsal Raphe Nucleus and Hippocampus of Insomnia Rats. MICROMACHINES 2022; 13:mi13030488. [PMID: 35334780 PMCID: PMC8950864 DOI: 10.3390/mi13030488] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Revised: 03/11/2022] [Accepted: 03/16/2022] [Indexed: 02/04/2023]
Abstract
Research on the intracerebral mechanism of insomnia induced by serotonin (5-HT) deficiency is indispensable. In order to explore the effect of 5-HT deficiency-induced insomnia on brain regions related to memory in rats, we designed and fabricated a microelectrode array that simultaneously detects the electrical activity of the dorsal raphe nucleus (DRN) and hippocampus in normal, insomnia and recovery rats in vivo. In the DRN and hippocampus of insomnia rats, our results showed that the spike amplitudes decreased by 40.16 and 57.92%, the spike repolarization slope decreased by 44.64 and 48.59%, and the spiking rate increased by 66.81 and 63.40%. On a mesoscopic scale, the increased firing rates of individual neurons led to an increased δ wave power. In the DRN and hippocampus of insomnia rats, the δ wave power increased by 57.57 and 67.75%. Furthermore, two segments’ δ wave slopes were also increased in two brain regions of the insomnia rats. Our findings suggest that 5-HT deficiency causes the hyperactivity of neurons in the hippocampus and DRN; the DRN’s firing rate and the hippocampal neuronal amplitude reflect insomnia in rats more effectively. Further studies on alleviating neurons affected by 5-HT deficiency and on achieving a highly effective treatment for insomnia by the microelectrode array are needed.
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24
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Balakrishnan G, Song J, Mou C, Bettinger CJ. Recent Progress in Materials Chemistry to Advance Flexible Bioelectronics in Medicine. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2022; 34:e2106787. [PMID: 34751987 PMCID: PMC8917047 DOI: 10.1002/adma.202106787] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Revised: 10/15/2021] [Indexed: 05/09/2023]
Abstract
Designing bioelectronic devices that seamlessly integrate with the human body is a technological pursuit of great importance. Bioelectronic medical devices that reliably and chronically interface with the body can advance neuroscience, health monitoring, diagnostics, and therapeutics. Recent major efforts focus on investigating strategies to fabricate flexible, stretchable, and soft electronic devices, and advances in materials chemistry have emerged as fundamental to the creation of the next generation of bioelectronics. This review summarizes contemporary advances and forthcoming technical challenges related to three principal components of bioelectronic devices: i) substrates and structural materials, ii) barrier and encapsulation materials, and iii) conductive materials. Through notable illustrations from the literature, integration and device fabrication strategies and associated challenges for each material class are highlighted.
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Affiliation(s)
| | - Jiwoo Song
- Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, PA, 15213, USA
| | - Chenchen Mou
- Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, PA, 15213, USA
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25
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Zhao H, Liu R, Zhang H, Cao P, Liu Z, Li Y. Research Progress on the Flexibility of an Implantable Neural Microelectrode. MICROMACHINES 2022; 13:386. [PMID: 35334680 PMCID: PMC8954487 DOI: 10.3390/mi13030386] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Revised: 12/25/2021] [Accepted: 01/16/2022] [Indexed: 12/22/2022]
Abstract
Neural microelectrode is the important bridge of information exchange between the human body and machines. By recording and transmitting nerve signals with electrodes, people can control the external machines. At the same time, using electrodes to electrically stimulate nerve tissue, people with long-term brain diseases will be safely and reliably treated. Young's modulus of the traditional rigid electrode probe is not matched well with that of biological tissue, and tissue immune rejection is easy to generate, resulting in the electrode not being able to achieve long-term safety and reliable working. In recent years, the choice of flexible materials and design of electrode structures can achieve modulus matching between electrode and biological tissue, and tissue damage is decreased. This review discusses nerve microelectrodes based on flexible electrode materials and substrate materials. Simultaneously, different structural designs of neural microelectrodes are reviewed. However, flexible electrode probes are difficult to implant into the brain. Only with the aid of certain auxiliary devices, can the implant be safe and reliable. The implantation method of the nerve microelectrode is also reviewed.
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Affiliation(s)
- Huiqing Zhao
- Beijing Institute of Graphic Communication, Beijing 102600, China
| | - Ruping Liu
- Beijing Institute of Graphic Communication, Beijing 102600, China
| | - Huiling Zhang
- Beijing Institute of Graphic Communication, Beijing 102600, China
| | - Peng Cao
- Beijing Institute of Graphic Communication, Beijing 102600, China
| | - Zilong Liu
- Division of Optics, National Institute of Metrology, Beijing 100029, China
| | - Ye Li
- Beijing Institute of Graphic Communication, Beijing 102600, China
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26
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Berggren M, Głowacki ED, Simon DT, Stavrinidou E, Tybrandt K. In Vivo Organic Bioelectronics for Neuromodulation. Chem Rev 2022; 122:4826-4846. [PMID: 35050623 PMCID: PMC8874920 DOI: 10.1021/acs.chemrev.1c00390] [Citation(s) in RCA: 40] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Indexed: 01/27/2023]
Abstract
The nervous system poses a grand challenge for integration with modern electronics and the subsequent advances in neurobiology, neuroprosthetics, and therapy which would become possible upon such integration. Due to its extreme complexity, multifaceted signaling pathways, and ∼1 kHz operating frequency, modern complementary metal oxide semiconductor (CMOS) based electronics appear to be the only technology platform at hand for such integration. However, conventional CMOS-based electronics rely exclusively on electronic signaling and therefore require an additional technology platform to translate electronic signals into the language of neurobiology. Organic electronics are just such a technology platform, capable of converting electronic addressing into a variety of signals matching the endogenous signaling of the nervous system while simultaneously possessing favorable material similarities with nervous tissue. In this review, we introduce a variety of organic material platforms and signaling modalities specifically designed for this role as "translator", focusing especially on recent implementation in in vivo neuromodulation. We hope that this review serves both as an informational resource and as an encouragement and challenge to the field.
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Affiliation(s)
- Magnus Berggren
- Laboratory
of Organic Electronics, Department of Science and Technology, Linköping University, 601 74 Norrköping, Sweden
| | - Eric D. Głowacki
- Laboratory
of Organic Electronics, Department of Science and Technology, Linköping University, 601 74 Norrköping, Sweden
- Bioelectronics
Materials and Devices, Central European
Institute of Technology, Brno University of Technology, Purkyňova 656/123, 612 00 Brno, Czech
Republic
| | - Daniel T. Simon
- Laboratory
of Organic Electronics, Department of Science and Technology, Linköping University, 601 74 Norrköping, Sweden
| | - Eleni Stavrinidou
- Laboratory
of Organic Electronics, Department of Science and Technology, Linköping University, 601 74 Norrköping, Sweden
| | - Klas Tybrandt
- Laboratory
of Organic Electronics, Department of Science and Technology, Linköping University, 601 74 Norrköping, Sweden
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27
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Cointe C, Laborde A, Nowak LG, Arvanitis DN, Bourrier D, Bergaud C, Maziz A. Scalable batch fabrication of ultrathin flexible neural probes using a bioresorbable silk layer. MICROSYSTEMS & NANOENGINEERING 2022; 8:21. [PMID: 35251687 PMCID: PMC8847482 DOI: 10.1038/s41378-022-00353-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Revised: 11/26/2021] [Accepted: 12/19/2021] [Indexed: 06/14/2023]
Abstract
Flexible intracerebral probes for neural recording and electrical stimulation have been the focus of many research works to achieve better compliance with the surrounding tissue while minimizing rejection. Strategies have been explored to find the best way to insert flexible probes into the brain while maintaining their flexibility once positioned. Here, we present a novel and versatile scalable batch fabrication approach to deliver ultrathin and flexible probes consisting of a silk-parylene bilayer. The biodegradable silk layer, whose degradation time is programmable, provides a temporary and programmable stiffener to allow the insertion of ultrathin parylene-based flexible devices. Our innovative and robust batch fabrication technology allows complete freedom over probe design in terms of materials, size, shape, and thickness. We demonstrate successful ex vivo insertion of the probe with acute high-fidelity recordings of epileptic seizures in field potentials as well as single-unit action potentials in mouse brain slices. Our novel technological solution for implanting ultraflexible devices in the brain while minimizing rejection risks shows high potential for use in both brain research and clinical therapies.
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Affiliation(s)
- Clement Cointe
- LAAS-CNRS, 7 Avenue du Colonel Roche, F-31400 Toulouse, France
| | - Adrian Laborde
- LAAS-CNRS, 7 Avenue du Colonel Roche, F-31400 Toulouse, France
| | - Lionel G. Nowak
- CerCo, Université Toulouse 3, CNRS, Pavillon Baudot, CHU Purpan, BP 25202, 31052 Toulouse, France
| | - Dina N. Arvanitis
- UMR Institut National de la Santé et de la Recherche Médicale 1048, Institut des Maladies Métaboliques et Cardiovasculaires, Toulouse, France
| | - David Bourrier
- LAAS-CNRS, 7 Avenue du Colonel Roche, F-31400 Toulouse, France
| | | | - Ali Maziz
- LAAS-CNRS, 7 Avenue du Colonel Roche, F-31400 Toulouse, France
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28
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Flexible Neural Probes with Optical Artifact-Suppressing Modification and Biofriendly Polypeptide Coating. MICROMACHINES 2022; 13:mi13020199. [PMID: 35208323 PMCID: PMC8877708 DOI: 10.3390/mi13020199] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Revised: 01/23/2022] [Accepted: 01/23/2022] [Indexed: 11/24/2022]
Abstract
The advent of optogenetics provides a well-targeted tool to manipulate neurons because of its high time resolution and cell-type specificity. Recently, closed-loop neural manipulation techniques consisting of optical stimulation and electrical recording have been widely used. However, metal microelectrodes exposed to light radiation could generate photoelectric noise, thus causing loss or distortion of neural signal in recording channels. Meanwhile, the biocompatibility of neural probes remains to be improved. Here, five kinds of neural interface materials are deposited on flexible polyimide-based neural probes and illuminated with a series of blue laser pulses to study their electrochemical performance and photoelectric noises for single-unit recording. The results show that the modifications can not only improve the electrochemical performance, but can also reduce the photoelectric artifacts. In particular, the double-layer composite consisting of platinum-black and conductive polymer has the best comprehensive performance. Thus, a layer of polypeptide is deposited on the entire surface of the double-layer modified neural probes to further improve their biocompatibility. The results show that the biocompatible polypeptide coating has little effect on the electrochemical performance of the neural probe, and it may serve as a drug carrier due to its special micromorphology.
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29
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Apartsin E, Venyaminova A, Majoral JP, Caminade AM. Dendriplex-Impregnated Hydrogels With Programmed Release Rate. Front Chem 2022; 9:780608. [PMID: 35071182 PMCID: PMC8766751 DOI: 10.3389/fchem.2021.780608] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Accepted: 12/13/2021] [Indexed: 12/24/2022] Open
Abstract
Hydrogels are biocompatible matrices for local delivery of nucleic acids; however, functional dopants are required to provide efficient delivery into cells. In particular, dendrimers, known as robust nucleic acid carriers, can be used as dopants. Herein, we report the first example of impregnating neutral hydrogels with siRNA-dendrimer complexes. The surface chemistry of dendrimers allows adjusting the release rate of siRNA-containing complexes. This methodology can bring new materials for biomedical applications.
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Affiliation(s)
- Evgeny Apartsin
- Laboratoire de Chimie de Coordination, CNRS, Toulouse, France.,LCC-CNRS, Université de Toulouse, CNRS, Toulouse, France.,Institute of Chemical Biology and Fundamental Medicine SB RAS, Novosibirsk, Russia.,Novosibirsk State University, Novosibirsk, Russia
| | - Alya Venyaminova
- Institute of Chemical Biology and Fundamental Medicine SB RAS, Novosibirsk, Russia
| | - Jean-Pierre Majoral
- Laboratoire de Chimie de Coordination, CNRS, Toulouse, France.,LCC-CNRS, Université de Toulouse, CNRS, Toulouse, France
| | - Anne-Marie Caminade
- Laboratoire de Chimie de Coordination, CNRS, Toulouse, France.,LCC-CNRS, Université de Toulouse, CNRS, Toulouse, France
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30
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Otte E, Vlachos A, Asplund M. Engineering strategies towards overcoming bleeding and glial scar formation around neural probes. Cell Tissue Res 2022; 387:461-477. [PMID: 35029757 PMCID: PMC8975777 DOI: 10.1007/s00441-021-03567-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Accepted: 12/17/2021] [Indexed: 12/15/2022]
Abstract
Neural probes are sophisticated electrophysiological tools used for intra-cortical recording and stimulation. These microelectrode arrays, designed to penetrate and interface the brain from within, contribute at the forefront of basic and clinical neuroscience. However, one of the challenges and currently most significant limitations is their ‘seamless’ long-term integration into the surrounding brain tissue. Following implantation, which is typically accompanied by bleeding, the tissue responds with a scarring process, resulting in a gliotic region closest to the probe. This glial scarring is often associated with neuroinflammation, neurodegeneration, and a leaky blood–brain interface (BBI). The engineering progress on minimizing this reaction in the form of improved materials, microfabrication, and surgical techniques is summarized in this review. As research over the past decade has progressed towards a more detailed understanding of the nature of this biological response, it is time to pose the question: Are penetrating probes completely free from glial scarring at all possible?
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31
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Hong JW, Yoon C, Jo K, Won JH, Park S. Recent advances in recording and modulation technologies for next-generation neural interfaces. iScience 2021; 24:103550. [PMID: 34917907 PMCID: PMC8666678 DOI: 10.1016/j.isci.2021.103550] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Along with the advancement in neural engineering techniques, unprecedented progress in the development of neural interfaces has been made over the past few decades. However, despite these achievements, there is still room for further improvements especially toward the possibility of monitoring and modulating neural activities with high resolution and specificity in our daily lives. In an effort of taking a step toward the next-generation neural interfaces, we want to highlight the recent progress in neural technologies. We will cover a wide scope of such developments ranging from novel platforms for highly specific recording and modulation to system integration for practical applications of novel interfaces.
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Affiliation(s)
- Ji-Won Hong
- Program of Brain and Cognitive Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea
| | - Chanwoong Yoon
- Program of Brain and Cognitive Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea
| | - Kyunghyun Jo
- Program of Brain and Cognitive Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea
| | - Joon Hee Won
- Program of Brain and Cognitive Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea
| | - Seongjun Park
- Program of Brain and Cognitive Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea.,Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea.,KAIST Institute of Health Science and Technology (KIHST), Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea
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32
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Ahmed Z, Reddy JW, Malekoshoaraie MH, Hassanzade V, Kimukin I, Jain V, Chamanzar M. Flexible optoelectric neural interfaces. Curr Opin Biotechnol 2021; 72:121-130. [PMID: 34826682 PMCID: PMC9741731 DOI: 10.1016/j.copbio.2021.11.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Revised: 10/30/2021] [Accepted: 11/02/2021] [Indexed: 12/14/2022]
Abstract
Understanding the neural basis of brain function and dysfunction and designing effective therapeutics require high resolution targeted stimulation and recording of neural activity. Optical methods have been recently developed for neural stimulation as well as functional and structural imaging. These methods call for implantable devices to deliver light into the neural tissue at depth with high spatiotemporal resolution. To address this need, rigid and flexible neurophotonic implants have been recently designed. This article reviews the state-of-the-art flexible passive and active penetrating optical neural probes developed for light delivery with minimal damage to the tissue. Passive and active flexible neurophotonic implants are compared and insights about future directions are provided.
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Affiliation(s)
- Zabir Ahmed
- Department of Electrical and Computer Engineering, Carnegie Mellon University, Pittsburgh, PA 15213, United States
| | - Jay W Reddy
- Department of Electrical and Computer Engineering, Carnegie Mellon University, Pittsburgh, PA 15213, United States
| | - Mohammad H Malekoshoaraie
- Department of Electrical and Computer Engineering, Carnegie Mellon University, Pittsburgh, PA 15213, United States
| | - Vahid Hassanzade
- Department of Electrical and Computer Engineering, Carnegie Mellon University, Pittsburgh, PA 15213, United States
| | - Ibrahim Kimukin
- Department of Electrical and Computer Engineering, Carnegie Mellon University, Pittsburgh, PA 15213, United States
| | - Vishal Jain
- Department of Electrical and Computer Engineering, Carnegie Mellon University, Pittsburgh, PA 15213, United States
| | - Maysamreza Chamanzar
- Department of Electrical and Computer Engineering, Carnegie Mellon University, Pittsburgh, PA 15213, United States.
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33
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Raghuram V, Werginz P, Fried SI, Timko BP. Morphological Factors that Underlie Neural Sensitivity to Stimulation in the Retina. ADVANCED NANOBIOMED RESEARCH 2021; 1:2100069. [PMID: 35399546 PMCID: PMC8993153 DOI: 10.1002/anbr.202100069] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Retinal prostheses are a promising therapeutic intervention for patients afflicted by outer retinal degenerative diseases like retinitis pigmentosa and age-related macular degeneration. While significant advances in the development of retinal implants have been made, the quality of vision elicited by these devices remains largely sub-optimal. The variability in the responses produced by retinal devices is most likely due to the differences between the natural cell type-specific signaling that occur in the healthy retina vs. the non-specific activation of multiple cell types arising from artificial stimulation. In order to replicate these natural signaling patterns, stimulation strategies must be capable of preferentially activating specific RGC types. To design more selective stimulation strategies, a better understanding of the morphological factors that underlie the sensitivity to prosthetic stimulation must be developed. This review will focus on the role that different anatomical components play in driving the direct activation of RGCs by extracellular stimulation. Briefly, it will (1) characterize the variability in morphological properties of α-RGCs, (2) detail the influence of morphology on the direct activation of RGCs by electric stimulation, and (3) describe some of the potential biophysical mechanisms that could explain differences in activation thresholds and electrically evoked responses between RGC types.
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Affiliation(s)
- Vineeth Raghuram
- Boston VA Healthcare System, 150 S Huntington Ave, Boston, MA 02130, USA
- Dept. of Biomedical Engineering, Tufts University, 4 Colby Street, Medford, MA 02155, USA
- Dept. of Neurosurgery, Massachusetts General Hospital - Harvard Medical School, 50 Blossom Street, Boston, MA, 02114
| | - Paul Werginz
- Institute for Analysis and Scientific Computing, Vienna University of Technology, Wiedner Hauptstrasse 8-10, Vienna, Austria
- Dept. of Neurosurgery, Massachusetts General Hospital - Harvard Medical School, 50 Blossom Street, Boston, MA, 02114
| | - Shelley I. Fried
- Boston VA Healthcare System, 150 S Huntington Ave, Boston, MA 02130, USA
- Dept. of Biomedical Engineering, Tufts University, 4 Colby Street, Medford, MA 02155, USA
- Dept. of Neurosurgery, Massachusetts General Hospital - Harvard Medical School, 50 Blossom Street, Boston, MA, 02114
| | - Brian P. Timko
- Dept. of Biomedical Engineering, Tufts University, 4 Colby Street, Medford, MA 02155, USA
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34
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Kilias A, Lee YT, Froriep UP, Sielaff C, Moser D, Holzhammer T, Egert U, Fang W, Paul O, Ruther P. Intracortical probe arrays with silicon backbone and microelectrodes on thin polyimide wings enable long-term stable recordings in vivo. J Neural Eng 2021; 18. [PMID: 34781276 DOI: 10.1088/1741-2552/ac39b7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Accepted: 11/15/2021] [Indexed: 11/12/2022]
Abstract
Objective.Recording and stimulating neuronal activity across different brain regions requires interfacing at multiple sites using dedicated tools while tissue reactions at the recording sites often prevent their successful long-term application. This implies the technological challenge of developing complex probe geometries while keeping the overall footprint minimal, and of selecting materials compatible with neural tissue. While the potential of soft materials in reducing tissue response is uncontested, the implantation of these materials is often limited to reliably target neuronal structures across large brain volumes.Approach.We report on the development of a new multi-electrode array exploiting the advantages of soft and stiff materials by combining 7-µm-thin polyimide wings carrying platinum electrodes with a silicon backbone enabling a safe probe implantation. The probe fabrication applies microsystems technologies in combination with a temporal wafer fixation method for rear side processing, i.e. grinding and deep reactive ion etching, of slender probe shanks and electrode wings. The wing-type neural probes are chronically implanted into the entorhinal-hippocampal formation in the mouse forin vivorecordings of freely behaving animals.Main results.Probes comprising the novel wing-type electrodes have been realized and characterized in view of their electrical performance and insertion capability. Chronic electrophysiologicalin vivorecordings of the entorhinal-hippocampal network in the mouse of up to 104 days demonstrated a stable yield of channels containing identifiable multi-unit and single-unit activity outperforming probes with electrodes residing on a Si backbone.Significance.The innovative fabrication process using a process compatible, temporary wafer bonding allowed to realize new Michigan-style probe arrays. The wing-type probe design enables a precise probe insertion into brain tissue and long-term stable recordings of unit activity due to the application of a stable backbone and 7-µm-thin probe wings provoking locally a minimal tissue response and protruding from the glial scare of the backbone.
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Affiliation(s)
- Antje Kilias
- Biomicrotechnology, Department of Microsystems Engineering (IMTEK), University of Freiburg, Freiburg, Germany.,Bernstein Center Freiburg, University of Freiburg, Freiburg, Germany
| | - Yu-Tao Lee
- Microsystem Materials Laboratory, Department of Microsystems Engineering (IMTEK), University of Freiburg, Freiburg, Germany.,Institute of NanoEngineering and Microsystems, National Tsing-Hua University, Hsinchu, Taiwan
| | - Ulrich P Froriep
- Biomicrotechnology, Department of Microsystems Engineering (IMTEK), University of Freiburg, Freiburg, Germany.,Bernstein Center Freiburg, University of Freiburg, Freiburg, Germany.,Department of Implant Systems, Fraunhofer Institute for Toxicology and Experimental Medicine ITEM, Hannover, Germany
| | - Charlotte Sielaff
- Department of Implant Systems, Fraunhofer Institute for Toxicology and Experimental Medicine ITEM, Hannover, Germany
| | - Dominik Moser
- Microsystem Materials Laboratory, Department of Microsystems Engineering (IMTEK), University of Freiburg, Freiburg, Germany
| | - Tobias Holzhammer
- Microsystem Materials Laboratory, Department of Microsystems Engineering (IMTEK), University of Freiburg, Freiburg, Germany
| | - Ulrich Egert
- Biomicrotechnology, Department of Microsystems Engineering (IMTEK), University of Freiburg, Freiburg, Germany.,Bernstein Center Freiburg, University of Freiburg, Freiburg, Germany.,Cluster of Excellence BrainLinks-BrainTools, University of Freiburg, Freiburg, Germany
| | - Weileun Fang
- Department of Power Mechanical Engineering, National Tsing Hua University, Hsinchu City, Taiwan
| | - Oliver Paul
- Microsystem Materials Laboratory, Department of Microsystems Engineering (IMTEK), University of Freiburg, Freiburg, Germany.,Cluster of Excellence BrainLinks-BrainTools, University of Freiburg, Freiburg, Germany
| | - Patrick Ruther
- Microsystem Materials Laboratory, Department of Microsystems Engineering (IMTEK), University of Freiburg, Freiburg, Germany.,Cluster of Excellence BrainLinks-BrainTools, University of Freiburg, Freiburg, Germany
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35
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Abstract
Water-responsive polymers, which enable the design of objects whose mechanical properties or shape can be altered upon moderate swelling, are useful for a broad range of applications. However, the limited processing options of materials that exhibit useful switchable mechanical properties generally restricted their application to objects having a simple geometry. Here we show that this problem can be overcome by using a negative photoresist approach in which a linear hydrophilic polymer is converted into a highly transparent cross-linked polymer network. The photolithographic process allows the facile production of objects of complex shape and permits programming of the cross-link density, the extent of aqueous swelling, and thereby the stiffness and refractive index under physiological conditions over a wide range and with high spatial resolution. Our findings validate a straightforward route to fabricate mechanically adaptive devices for a variety of (biomedical) uses, notably optogenetic implants whose overall shape, mechanical contrast, and optical channels can all be defined by photolithography.
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36
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Rapeaux AB, Constandinou TG. Implantable brain machine interfaces: first-in-human studies, technology challenges and trends. Curr Opin Biotechnol 2021; 72:102-111. [PMID: 34749248 DOI: 10.1016/j.copbio.2021.10.001] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 09/29/2021] [Accepted: 10/02/2021] [Indexed: 11/29/2022]
Abstract
Implantable brain machine interfaces (BMIs) are now on a trajectory to go mainstream, wherein what was once considered last resort will progressively become elective at earlier stages in disease treatment. First-in-human successes have demonstrated the ability to decode highly dexterous motor skills such as handwriting, and speech from human cortical activity. These have been used for cursor and prosthesis control, direct-to-text communication and speech synthesis. Along with these breakthrough studies, technology advancements have enabled the observation of more channels of neural activity through new concepts for centralised/distributed implant architectures. This is complemented by research in flexible substrates, packaging, surgical workflows and data processing. New regulatory guidance and funding has galvanised the field. This culmination of resource, efforts and capability is now attracting significant investment for BMI commercialisation. This paper reviews recent developments and describes the paradigm shift in BMI development that is leading to new innovations, insights and BMI translation.
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Affiliation(s)
- Adrien B Rapeaux
- Department of Electrical and Electronic Engineering, Imperial College London, UK; Centre for Bio-Inspired Technology, Imperial College London, UK; Care Research and Technology (CR&T) based at Imperial College London and the University of Surrey, UK Dementia Research Institute (UK DRI), UK
| | - Timothy G Constandinou
- Department of Electrical and Electronic Engineering, Imperial College London, UK; Centre for Bio-Inspired Technology, Imperial College London, UK; Care Research and Technology (CR&T) based at Imperial College London and the University of Surrey, UK Dementia Research Institute (UK DRI), UK.
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37
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Reddy JW, Malekoshoaraie MH, Hassanzade V, Venkateswaran R, Chamanzar M. Parylene Photonic Microimager for Implantable Imaging . ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2021; 2021:7511-7514. [PMID: 34892830 DOI: 10.1109/embc46164.2021.9630912] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
We have recently introduced a fully flexible, compact photonic platform, Parylene photonics. Here, we demonstrate a Parylene photonic waveguide array microimager with a light source localization accuracy of 17.04 µm along the x-axis and 30.07 µm along the y-axis over a 200 µm×1000 µm region. We show the feasibility of fluorescent imaging from mouse brain tissue using the microimager array.Clinical Relevance- Implantable microimagers can be used for clinical intraoperative monitoring as well as structural and functional imaging with cell-type specificity in research.
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Kumosa LS, Schouenborg J. Profound alterations in brain tissue linked to hypoxic episode after device implantation. Biomaterials 2021; 278:121143. [PMID: 34653937 DOI: 10.1016/j.biomaterials.2021.121143] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2021] [Accepted: 09/20/2021] [Indexed: 12/17/2022]
Abstract
To enable authentic interfacing with neuronal structures in the brain, preventing alterations of tissue during implantation of devices is critical. By transiently implanting oxygen microsensors into rat cortex cerebri for 2 h, substantial and long lasting (>1 h) hypoxia is routinely generated in surrounding tissues; this hypoxia is linked to implantation generated compressive forces. Preferential loss of larger neurons and reduced metabolic components in surviving neurons indicates decreased viability one week after such hypoxic, compressive implantations. By devising an implantation method that relaxes compressive forces; magnitude and duration of hypoxia generated following such an implantation are ameliorated and neurons appear similar to naïve tissues. In line with these observations, astrocyte proliferation was significantly more pronounced for more hypoxic, compressive implantations. Surprisingly, astrocyte processes were frequently found to traverse cellular boundaries into nearby neuronal nuclei, indicating injury induction of a previously not described astrocyte-neuron interaction. Found more frequently in less hypoxic, force-relaxed insertions and thus correlating to a more beneficial outcome, this finding may suggest a novel protective mechanism. In conclusion, substantial and long lasting insertion induced hypoxia around brain implants, a previously overlooked factor, is linked to significant adverse alterations in nervous tissue.
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Affiliation(s)
- Lucas S Kumosa
- Neuronano Research Center, Faculty of Medicine, Lund University, Scheelevägen 2, Medicon Village 404A2, 223 81, Lund, Sweden.
| | - Jens Schouenborg
- Neuronano Research Center, Faculty of Medicine, Lund University, Scheelevägen 2, Medicon Village 404A2, 223 81, Lund, Sweden; NanoLund, Lund University, Professorsgatan 1, 223 63, Lund, Sweden.
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Forni M, Thorbergsson PT, Thelin J, Schouenborg J. 3D microelectrode cluster and stimulation paradigm yield powerful analgesia without noticeable adverse effects. SCIENCE ADVANCES 2021; 7:eabj2847. [PMID: 34623922 PMCID: PMC8500508 DOI: 10.1126/sciadv.abj2847] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Accepted: 08/19/2021] [Indexed: 06/13/2023]
Abstract
The lack of satisfactory treatment for persistent pain profoundly impairs the quality of life for many patients. Stimulation of brainstem pain control systems can trigger powerful analgesia, but their complex network organization frequently prevents separation of analgesia from side effects. To overcome this long-standing challenge, we developed a biocompatible gelatin-embedded cluster of ultrathin microelectrodes that enables fine-tuned, high-definition three-dimensional stimulation in periaqueductal gray/dorsal raphe nucleus in awake rats. Analgesia was assessed from both motor reactions and intracortical signals, corresponding to pain-related signals in humans. We could select an individual-specific subset of microelectrodes in each animal that reliably provided strong pain inhibition during normal and hyperalgesia conditions, without noticeable behavioral side effects. Gait, spontaneous cortical activity at rest, and cortical tactile responses were minimally affected, indicating a highly selective action. In conclusion, our developed biocompatible microelectrode cluster and stimulation paradigm reliably enabled powerful, fine-tuned, and selective analgesia without noticeable side effects.
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Affiliation(s)
- Matilde Forni
- Neuronano Research Center, Department of Experimental Medical Sciences, Medical Faculty, Lund University, Medicon Village, Scheelevägen 2, Lund, 223 81, Sweden
| | - Palmi Thor Thorbergsson
- Neuronano Research Center, Department of Experimental Medical Sciences, Medical Faculty, Lund University, Medicon Village, Scheelevägen 2, Lund, 223 81, Sweden
| | - Jonas Thelin
- Neuronano Research Center, Department of Experimental Medical Sciences, Medical Faculty, Lund University, Medicon Village, Scheelevägen 2, Lund, 223 81, Sweden
| | - Jens Schouenborg
- Neuronano Research Center, Department of Experimental Medical Sciences, Medical Faculty, Lund University, Medicon Village, Scheelevägen 2, Lund, 223 81, Sweden
- NanoLund, Center for Nanoscience, Lund University, Professorsgatan 1, Lund 223 63, Sweden
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Srikantharajah K, Medinaceli Quintela R, Doerenkamp K, Kampa BM, Musall S, Rothermel M, Offenhäusser A. Minimally-invasive insertion strategy and in vivo evaluation of multi-shank flexible intracortical probes. Sci Rep 2021; 11:18920. [PMID: 34556704 PMCID: PMC8460634 DOI: 10.1038/s41598-021-97940-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2021] [Accepted: 08/26/2021] [Indexed: 11/16/2022] Open
Abstract
Chronically implanted neural probes are powerful tools to decode brain activity however, recording population and spiking activity over long periods remains a major challenge. Here, we designed and fabricated flexible intracortical Michigan-style arrays with a shank cross-section per electrode of 250 μm[Formula: see text] utilizing the polymer paryleneC with the goal to improve the immune acceptance. As flexible neural probes are unable to penetrate the brain due to the low buckling force threshold, a tissue-friendly insertion system was developed by reducing the effective shank length. The insertion strategy enabled the implantation of the four, bare, flexible shanks up to 2 mm into the mouse brain without increasing the implantation footprint and therefore, minimizing the acute trauma. In acute recordings from the mouse somatosensory cortex and the olfactory bulb, we demonstrated that the flexible probes were able to simultaneously detect local field potentials as well as single and multi-unit activity. Additionally, the flexible arrays outperformed stiff probes with respect to yield of single unit activity. Following the successful in vivo validation, we further improved the microfabrication towards a double-metal-layer process, and were able to double the number of electrodes per shank by keeping the shank width resulting in a cross-section per electrode of 118 μm[Formula: see text].
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Affiliation(s)
- Kagithiri Srikantharajah
- Bioelectronics, Institute of Biological Information Processing-3, Forschungszentrum Jülich, Jülich, Germany
- RWTH Aachen University, Aachen, Germany
| | - Renata Medinaceli Quintela
- Institute for Physiology and Cell Biology, University of Veterinary Medicine, Foundation, Hannover, Germany
| | - Kerstin Doerenkamp
- Department of Neurophysiology, Institute for Biology II, RWTH Aachen University, Aachen, Germany
| | - Björn M Kampa
- Department of Neurophysiology, Institute for Biology II, RWTH Aachen University, Aachen, Germany
- JARA BRAIN, Institute for Neuroscience and Medicine, Forschungszentrum Jülich, Jülich, Germany
| | - Simon Musall
- Bioelectronics, Institute of Biological Information Processing-3, Forschungszentrum Jülich, Jülich, Germany
| | - Markus Rothermel
- Institute for Physiology and Cell Biology, University of Veterinary Medicine, Foundation, Hannover, Germany
| | - Andreas Offenhäusser
- Bioelectronics, Institute of Biological Information Processing-3, Forschungszentrum Jülich, Jülich, Germany.
- RWTH Aachen University, Aachen, Germany.
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Salahuddin U, Gao PX. Signal Generation, Acquisition, and Processing in Brain Machine Interfaces: A Unified Review. Front Neurosci 2021; 15:728178. [PMID: 34588951 PMCID: PMC8475516 DOI: 10.3389/fnins.2021.728178] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Accepted: 08/18/2021] [Indexed: 11/13/2022] Open
Abstract
Brain machine interfaces (BMIs), or brain computer interfaces (BCIs), are devices that act as a medium for communications between the brain and the computer. It is an emerging field with numerous applications in domains of prosthetic devices, robotics, communication technology, gaming, education, and security. It is noted in such a multidisciplinary field, many reviews have surveyed on various focused subfields of interest, such as neural signaling, microelectrode fabrication, and signal classification algorithms. A unified review is lacking to cover and link all the relevant areas in this field. Herein, this review intends to connect on the relevant areas that circumscribe BMIs to present a unified script that may help enhance our understanding of BMIs. Specifically, this article discusses signal generation within the cortex, signal acquisition using invasive, non-invasive, or hybrid techniques, and the signal processing domain. The latest development is surveyed in this field, particularly in the last decade, with discussions regarding the challenges and possible solutions to allow swift disruption of BMI products in the commercial market.
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Affiliation(s)
- Usman Salahuddin
- Institute of Materials Science, University of Connecticut, Storrs, CT, United States
| | - Pu-Xian Gao
- Institute of Materials Science, University of Connecticut, Storrs, CT, United States
- Department of Materials Science and Engineering, University of Connecticut, Storrs, CT, United States
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Zhang Y, Gao X, Wu Y, Gui J, Guo S, Zheng H, Wang ZL. Self-powered technology based on nanogenerators for biomedical applications. EXPLORATION (BEIJING, CHINA) 2021; 1:90-114. [PMID: 37366464 PMCID: PMC10291576 DOI: 10.1002/exp.20210152] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Accepted: 07/09/2021] [Indexed: 06/28/2023]
Abstract
Biomedical electronic devices have enormous benefits for healthcare and quality of life. Still, the long-term working of those devices remains a great challenge due to the short life and large volume of conventional batteries. Since the nanogenerators (NGs) invention, they have been widely used to convert various ambient mechanical energy sources into electrical energy. The self-powered technology based on NGs is dedicated to harvesting ambient energy to supply electronic devices, which is an effective pathway to conquer the energy insufficiency of biomedical electronic devices. With the aid of this technology, it is expected to develop self-powered biomedical electronic devices with advanced features and distinctive functions. The goal of this review is to summarize the existing self-powered technologies based on NGs and then review the applications based on self-powered technologies in the biomedical field during their rapid development in recent years, including two main directions. The first is the NGs as independent sensors to converts biomechanical energy and heat energy into electrical signals to reflect health information. The second direction is to use the electrical energy produced by NGs to stimulate biological tissues or powering biomedical devices for achieving the purpose of medical application. Eventually, we have analyzed and discussed the remaining challenges and perspectives of the field. We believe that the self-powered technology based on NGs would advance the development of modern biomedical electronic devices.
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Affiliation(s)
- Yuanzheng Zhang
- Key Laboratory of Artificial Micro‐ and Nano‐structures of Ministry of EducationSchool of Physics and TechnologyWuhan UniversityWuhanP. R. China
- International Joint Research Laboratory of New Energy Materials and Devices of Henan ProvinceHenan UniversityKaifengP. R. China
| | - Xiangyang Gao
- Key Laboratory of Artificial Micro‐ and Nano‐structures of Ministry of EducationSchool of Physics and TechnologyWuhan UniversityWuhanP. R. China
| | - Yonghui Wu
- International Joint Research Laboratory of New Energy Materials and Devices of Henan ProvinceHenan UniversityKaifengP. R. China
| | - Jinzheng Gui
- Key Laboratory of Artificial Micro‐ and Nano‐structures of Ministry of EducationSchool of Physics and TechnologyWuhan UniversityWuhanP. R. China
| | - Shishang Guo
- Key Laboratory of Artificial Micro‐ and Nano‐structures of Ministry of EducationSchool of Physics and TechnologyWuhan UniversityWuhanP. R. China
| | - Haiwu Zheng
- International Joint Research Laboratory of New Energy Materials and Devices of Henan ProvinceHenan UniversityKaifengP. R. China
| | - Zhong Lin Wang
- Beijing Institute of Nanoenergy and NanosystemsChinese Academy of SciencesBeijingP. R. China
- School of Materials Science and EngineeringGeorgia Institute of TechnologyAtlantaGeorgiaUSA
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Implant Fibrosis and the Underappreciated Role of Myofibroblasts in the Foreign Body Reaction. Cells 2021; 10:cells10071794. [PMID: 34359963 PMCID: PMC8304203 DOI: 10.3390/cells10071794] [Citation(s) in RCA: 62] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 07/08/2021] [Accepted: 07/13/2021] [Indexed: 02/06/2023] Open
Abstract
Body implants and implantable medical devices have dramatically improved and prolonged the life of countless patients. However, our body repair mechanisms have evolved to isolate, reject, or destroy any object that is recognized as foreign to the organism and inevitably mounts a foreign body reaction (FBR). Depending on its severity and chronicity, the FBR can impair implant performance or create severe clinical complications that will require surgical removal and/or replacement of the faulty device. The number of review articles discussing the FBR seems to be proportional to the number of different implant materials and clinical applications and one wonders, what else is there to tell? We will here take the position of a fibrosis researcher (which, coincidentally, we are) to elaborate similarities and differences between the FBR, normal wound healing, and chronic healing conditions that result in the development of peri-implant fibrosis. After giving credit to macrophages in the inflammatory phase of the FBR, we will mainly focus on the activation of fibroblastic cells into matrix-producing and highly contractile myofibroblasts. While fibrosis has been discussed to be a consequence of the disturbed and chronic inflammatory milieu in the FBR, direct activation of myofibroblasts at the implant surface is less commonly considered. Thus, we will provide a perspective how physical properties of the implant surface control myofibroblast actions and accumulation of stiff scar tissue. Because formation of scar tissue at the surface and around implant materials is a major reason for device failure and extraction surgeries, providing implant surfaces with myofibroblast-suppressing features is a first step to enhance implant acceptance and functional lifetime. Alternative therapeutic targets are elements of the myofibroblast mechanotransduction and contractile machinery and we will end with a brief overview on such targets that are considered for the treatment of other organ fibroses.
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Kharbikar BN, Chendke GS, Desai TA. Modulating the foreign body response of implants for diabetes treatment. Adv Drug Deliv Rev 2021; 174:87-113. [PMID: 33484736 PMCID: PMC8217111 DOI: 10.1016/j.addr.2021.01.011] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 12/30/2020] [Accepted: 01/10/2021] [Indexed: 02/06/2023]
Abstract
Diabetes Mellitus is a group of diseases characterized by high blood glucose levels due to patients' inability to produce sufficient insulin. Current interventions often require implants that can detect and correct high blood glucose levels with minimal patient intervention. However, these implantable technologies have not reached their full potential in vivo due to the foreign body response and subsequent development of fibrosis. Therefore, for long-term function of implants, modulating the initial immune response is crucial in preventing the activation and progression of the immune cascade. This review discusses the different molecular mechanisms and cellular interactions involved in the activation and progression of foreign body response (FBR) and fibrosis, specifically for implants used in diabetes. We also highlight the various strategies and techniques that have been used for immunomodulation and prevention of fibrosis. We investigate how these general strategies have been applied to implants used for the treatment of diabetes, offering insights on how these devices can be further modified to circumvent FBR and fibrosis.
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Affiliation(s)
- Bhushan N Kharbikar
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Gauree S Chendke
- University of California Berkeley - University of California San Francisco Graduate Program in Bioengineering, San Francisco, CA 94143, USA
| | - Tejal A Desai
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, CA 94143, USA; University of California Berkeley - University of California San Francisco Graduate Program in Bioengineering, San Francisco, CA 94143, USA; Department of Bioengineering, University of California, Berkeley, CA 94720, USA.
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45
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Pimenta S, Rodrigues JA, Machado F, Ribeiro JF, Maciel MJ, Bondarchuk O, Monteiro P, Gaspar J, Correia JH, Jacinto L. Double-Layer Flexible Neural Probe With Closely Spaced Electrodes for High-Density in vivo Brain Recordings. Front Neurosci 2021; 15:663174. [PMID: 34211364 PMCID: PMC8239195 DOI: 10.3389/fnins.2021.663174] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Accepted: 05/19/2021] [Indexed: 11/13/2022] Open
Abstract
Flexible polymer neural probes are an attractive emerging approach for invasive brain recordings, given that they can minimize the risks of brain damage or glial scaring. However, densely packed electrode sites, which can facilitate neuronal data analysis, are not widely available in flexible probes. Here, we present a new flexible polyimide neural probe, based on standard and low-cost lithography processes, which has 32 closely spaced 10 μm diameter gold electrode sites at two different depths from the probe surface arranged in a matrix, with inter-site distances of only 5 μm. The double-layer design and fabrication approach implemented also provides additional stiffening just sufficient to prevent probe buckling during brain insertion. This approach avoids typical laborious augmentation strategies used to increase flexible probes’ mechanical rigidity while allowing a small brain insertion footprint. Chemical composition analysis and metrology of structural, mechanical, and electrical properties demonstrated the viability of this fabrication approach. Finally, in vivo functional assessment tests in the mouse cortex were performed as well as histological assessment of the insertion footprint, validating the biological applicability of this flexible neural probe for acquiring high quality neuronal recordings with high signal to noise ratio (SNR) and reduced acute trauma.
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Affiliation(s)
- Sara Pimenta
- CMEMS-UMinho, Department of Industrial Electronics, University of Minho, Guimarães, Portugal
| | - José A Rodrigues
- CMEMS-UMinho, Department of Industrial Electronics, University of Minho, Guimarães, Portugal
| | - Francisca Machado
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal.,ICVS/3B's-PT Government Associate Laboratory, Braga/Guimarães, Portugal
| | - João F Ribeiro
- CMEMS-UMinho, Department of Industrial Electronics, University of Minho, Guimarães, Portugal
| | - Marino J Maciel
- CMEMS-UMinho, Department of Industrial Electronics, University of Minho, Guimarães, Portugal
| | | | - Patricia Monteiro
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal.,ICVS/3B's-PT Government Associate Laboratory, Braga/Guimarães, Portugal
| | - João Gaspar
- International Iberian Nanotechnology Laboratory (INL), Braga, Portugal
| | - José H Correia
- CMEMS-UMinho, Department of Industrial Electronics, University of Minho, Guimarães, Portugal
| | - Luis Jacinto
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal.,ICVS/3B's-PT Government Associate Laboratory, Braga/Guimarães, Portugal
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Lanzio V, Telian G, Koshelev A, Micheletti P, Presti G, D’Arpa E, De Martino P, Lorenzon M, Denes P, West M, Sassolini S, Dhuey S, Adesnik H, Cabrini S. Small footprint optoelectrodes using ring resonators for passive light localization. MICROSYSTEMS & NANOENGINEERING 2021; 7:40. [PMID: 34567754 PMCID: PMC8433201 DOI: 10.1038/s41378-021-00263-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Revised: 02/16/2021] [Accepted: 03/30/2021] [Indexed: 05/31/2023]
Abstract
The combination of electrophysiology and optogenetics enables the exploration of how the brain operates down to a single neuron and its network activity. Neural probes are in vivo invasive devices that integrate sensors and stimulation sites to record and manipulate neuronal activity with high spatiotemporal resolution. State-of-the-art probes are limited by tradeoffs involving their lateral dimension, number of sensors, and ability to access independent stimulation sites. Here, we realize a highly scalable probe that features three-dimensional integration of small-footprint arrays of sensors and nanophotonic circuits to scale the density of sensors per cross-section by one order of magnitude with respect to state-of-the-art devices. For the first time, we overcome the spatial limit of the nanophotonic circuit by coupling only one waveguide to numerous optical ring resonators as passive nanophotonic switches. With this strategy, we achieve accurate on-demand light localization while avoiding spatially demanding bundles of waveguides and demonstrate the feasibility with a proof-of-concept device and its scalability towards high-resolution and low-damage neural optoelectrodes.
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Affiliation(s)
- Vittorino Lanzio
- The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 USA
- Department of Applied Science and Technology, Politecnico di Torino, Torino, 10129 Italy
| | - Gregory Telian
- Adesnik Lab, University of California Berkeley, Berkeley, CA 94720 USA
| | | | - Paolo Micheletti
- Department of Applied Science and Technology, Politecnico di Torino, Torino, 10129 Italy
| | - Gianni Presti
- The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 USA
| | - Elisa D’Arpa
- Department of Applied Science and Technology, Politecnico di Torino, Torino, 10129 Italy
| | - Paolo De Martino
- Department of Applied Science and Technology, Politecnico di Torino, Torino, 10129 Italy
| | - Monica Lorenzon
- The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 USA
| | - Peter Denes
- Lawrence Berkeley National Laboratory, (LBNL), Berkeley, CA 94720 USA
| | - Melanie West
- The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 USA
| | - Simone Sassolini
- The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 USA
| | - Scott Dhuey
- The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 USA
| | - Hillel Adesnik
- Adesnik Lab, University of California Berkeley, Berkeley, CA 94720 USA
| | - Stefano Cabrini
- The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 USA
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McGlynn E, Nabaei V, Ren E, Galeote‐Checa G, Das R, Curia G, Heidari H. The Future of Neuroscience: Flexible and Wireless Implantable Neural Electronics. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2021; 8:2002693. [PMID: 34026431 PMCID: PMC8132070 DOI: 10.1002/advs.202002693] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Revised: 01/15/2021] [Indexed: 05/04/2023]
Abstract
Neurological diseases are a prevalent cause of global mortality and are of growing concern when considering an ageing global population. Traditional treatments are accompanied by serious side effects including repeated treatment sessions, invasive surgeries, or infections. For example, in the case of deep brain stimulation, large, stiff, and battery powered neural probes recruit thousands of neurons with each pulse, and can invoke a vigorous immune response. This paper presents challenges in engineering and neuroscience in developing miniaturized and biointegrated alternatives, in the form of microelectrode probes. Progress in design and topology of neural implants has shifted the goal post toward highly specific recording and stimulation, targeting small groups of neurons and reducing the foreign body response with biomimetic design principles. Implantable device design recommendations, fabrication techniques, and clinical evaluation of the impact flexible, integrated probes will have on the treatment of neurological disorders are provided in this report. The choice of biocompatible material dictates fabrication techniques as novel methods reduce the complexity of manufacture. Wireless power, the final hurdle to truly implantable neural interfaces, is discussed. These aspects are the driving force behind continued research: significant breakthroughs in any one of these areas will revolutionize the treatment of neurological disorders.
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Affiliation(s)
- Eve McGlynn
- Microelectronics LabJames Watt School of EngineeringUniversity of GlasgowGlasgowG12 8QQUnited Kingdom
| | - Vahid Nabaei
- Microelectronics LabJames Watt School of EngineeringUniversity of GlasgowGlasgowG12 8QQUnited Kingdom
| | - Elisa Ren
- Laboratory of Experimental Electroencephalography and NeurophysiologyDepartment of BiomedicalMetabolic and Neural SciencesUniversity of Modena and Reggio EmiliaModena41125Italy
| | - Gabriel Galeote‐Checa
- Microelectronics LabJames Watt School of EngineeringUniversity of GlasgowGlasgowG12 8QQUnited Kingdom
| | - Rupam Das
- Microelectronics LabJames Watt School of EngineeringUniversity of GlasgowGlasgowG12 8QQUnited Kingdom
| | - Giulia Curia
- Laboratory of Experimental Electroencephalography and NeurophysiologyDepartment of BiomedicalMetabolic and Neural SciencesUniversity of Modena and Reggio EmiliaModena41125Italy
| | - Hadi Heidari
- Microelectronics LabJames Watt School of EngineeringUniversity of GlasgowGlasgowG12 8QQUnited Kingdom
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Monney B, Hess-Dunning AE, Gloth P, Capadona JR, Weder C. Mechanically adaptive implants fabricated with poly(2-hydroxyethyl methacrylate)-based negative photoresists. J Mater Chem B 2021; 8:6357-6365. [PMID: 32555874 DOI: 10.1039/d0tb00980f] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Neural implants that are based on mechanically adaptive polymers (MAPs) and soften upon insertion into the body have previously been demonstrated to elicit a reduced chronic tissue response than more rigid devices fabricated from silicon or metals, but their processability has been limited. Here we report a negative photoresist approach towards physiologically responsive MAPs. We exploited this framework to create cross-linked terpolymers of 2-hydroxyethyl methacrylate, 2-hydroxyethyl acrylate and 2-ethylhexyl methacrylate by photolithographic processes. Our systematic investigation of this platform afforded an optimized composition that exhibits a storage modulus E' of 1.8 GPa in the dry state. Upon exposure to simulated physiological conditions the material swells slightly (21% w/w) leading to a reduction of E' to 2 MPa. The large modulus change is mainly caused by plasticization, which shifts the glass transition from above to below 37 °C. Single shank probes fabricated by photolithography could readily be implanted into a brain-mimicking gel without buckling and viability studies with microglial cells show that the materials display excellent biocompatibility.
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Affiliation(s)
- Baptiste Monney
- Adolphe Merkle Institute, University of Fribourg, Chemin des Verdiers 4, CH-1700 Fribourg, Switzerland.
| | - Allison E Hess-Dunning
- Advanced Platform Technology Center, Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland, OH 44106, USA and Department of Biomedical Engineering, Case Western Reserve University, 2071 Martin Luther King Jr. Drive, Cleveland, OH 44106, USA
| | - Paul Gloth
- Advanced Platform Technology Center, Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland, OH 44106, USA and Department of Biomedical Engineering, Case Western Reserve University, 2071 Martin Luther King Jr. Drive, Cleveland, OH 44106, USA
| | - Jeffrey R Capadona
- Advanced Platform Technology Center, Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland, OH 44106, USA and Department of Biomedical Engineering, Case Western Reserve University, 2071 Martin Luther King Jr. Drive, Cleveland, OH 44106, USA
| | - Christoph Weder
- Adolphe Merkle Institute, University of Fribourg, Chemin des Verdiers 4, CH-1700 Fribourg, Switzerland.
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Sperry ZJ, Na K, Jun J, Madden LR, Socha A, Yoon E, Seymour JP, Bruns TM. High-density neural recordings from feline sacral dorsal root ganglia with thin-film array. J Neural Eng 2021; 18. [PMID: 33545709 DOI: 10.1088/1741-2552/abe398] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Accepted: 02/05/2021] [Indexed: 12/26/2022]
Abstract
Objective. Dorsal root ganglia (DRG) are promising sites for recording sensory activity. Current technologies for DRG recording are stiff and typically do not have sufficient site density for high-fidelity neural data techniques.Approach. In acute experiments, we demonstrate single-unit neural recordings in sacral DRG of anesthetized felines using a 4.5µm thick, high-density flexible polyimide microelectrode array with 60 sites and 30-40µm site spacing. We delivered arrays into DRG with ultrananocrystalline diamond shuttles designed for high stiffness affording a smaller footprint. We recorded neural activity during sensory activation, including cutaneous brushing and bladder filling, as well as during electrical stimulation of the pudendal nerve and anal sphincter. We used specialized neural signal analysis software to sort densely packed neural signals.Main results. We successfully delivered arrays in five of six experiments and recorded single-unit sensory activity in four experiments. The median neural signal amplitude was 55μV peak-to-peak and the maximum unique units recorded at one array position was 260, with 157 driven by sensory or electrical stimulation. In one experiment, we used the neural analysis software to track eight sorted single units as the array was retracted ∼500μm.Significance. This study is the first demonstration of ultrathin, flexible, high-density electronics delivered into DRG, with capabilities for recording and tracking sensory information that are a significant improvement over conventional DRG interfaces.
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Affiliation(s)
- Zachariah J Sperry
- Biomedical Engineering, University of Michigan, Ann Arbor, MI, United States of America.,Biointerfaces Institute, University of Michigan, Ann Arbor, MI, United States of America
| | - Kyounghwan Na
- Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, MI, United States of America
| | - James Jun
- Flatiron Institute, Simons Foundation, New York City, NY, United States of America
| | - Lauren R Madden
- Biomedical Engineering, University of Michigan, Ann Arbor, MI, United States of America.,Biointerfaces Institute, University of Michigan, Ann Arbor, MI, United States of America
| | - Alec Socha
- Biointerfaces Institute, University of Michigan, Ann Arbor, MI, United States of America.,Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, MI, United States of America
| | - Eusik Yoon
- Biomedical Engineering, University of Michigan, Ann Arbor, MI, United States of America.,Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, MI, United States of America.,Center for Nanomedicine, Institute for Basic Science (IBS) and Graduate Program of Nano Biomedical Engineering (NanoBME), Advanced Science Institute, Yonsei University, Seoul, Republic of Korea
| | - John P Seymour
- Biomedical Engineering, University of Michigan, Ann Arbor, MI, United States of America.,Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, MI, United States of America.,University of Texas Health Science Center, Department of Neurosurgery, Houston, TX, United States of America.,Department of Electrical and Computer Engineering, Rice University, Houston, TX, United States of America
| | - Tim M Bruns
- Biomedical Engineering, University of Michigan, Ann Arbor, MI, United States of America.,Biointerfaces Institute, University of Michigan, Ann Arbor, MI, United States of America
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Zhang W, Zhou X, He Y, Xu L, Xie J. Implanting mechanics of PEG/DEX coated flexible neural probe: impacts of fabricating methods. Biomed Microdevices 2021; 23:17. [PMID: 33730217 DOI: 10.1007/s10544-021-00552-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/10/2021] [Indexed: 12/15/2022]
Abstract
Resorbable coatings are processed on flexible implants to facilitate penetrations. However, impacts of fabricating methods on implantation damage of coated probes are unclear. Herein, photosensitive polyimide (PSPI) based flexible neural implants are fabricated through clean-room technology. Polyethyleneglycol (PEG) - dexamethasone (DEX) coatings are processed through an improved micro moulding protocol in micro channels, fabricated by computer-numerical-controlled (CNC) micro milling, laser machining, and deep reactive ion etching (DRIE), respectively. An in vitro testing system is developed, using maximum insertion force [Formula: see text] and mean region-of-interest strain [Formula: see text] to accurately evaluate effects of the three fabricating methods on implantation damage at different insertion speed. Rat cerebrum, agarose gel, and silicone rubber are used as brain phantoms for tests. Results show that lower insertion speed, and micro channels fabricated by CNC micro milling or DRIE can minimize implantation damage. The decrease of insertion speed from 2.0 mm/s to 0.5 mm/s reduces [Formula: see text] by 76.2% ~85.1% and [Formula: see text] by 11.6% ~14.7%, respectively. Compared with laser machining, CNC micro milling and DRIE ensure dimensional accuracy of the PEG/DEX coating, reducing [Formula: see text] by 20.2% ~51.4% and [Formula: see text] by 8.0% ~11.6%, respectively. Compared with biological rat cerebrum, [Formula: see text] reduces by 5.8% ~25.1% in agarose gel phantom and increases by 7.7% ~21.0% in silicone rubber phantom, respectively. This study improves processing methods of polymer coatings and reveals mechanical difference between current used abiotic brain phantoms and biological brain tissues. Implantation tests establish quantitative relationship among insertion speed, fabricating methods, and implantation damage.
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Affiliation(s)
- Wenguang Zhang
- School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai, China.
| | - Xuhui Zhou
- School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai, China
| | - Yuxin He
- School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai, China
| | - Liyue Xu
- School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai, China
| | - Jie Xie
- School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai, China
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