1
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Duncan JL, Wang JJ, Glusauskas G, Weagraff GR, Gao Y, Hoeferlin GF, Hunter AH, Hess-Dunning A, Ereifej ES, Capadona JR. In Vivo Characterization of Intracortical Probes with Focused Ion Beam-Etched Nanopatterned Topographies. Micromachines (Basel) 2024; 15:286. [PMID: 38399014 PMCID: PMC10893395 DOI: 10.3390/mi15020286] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2024] [Revised: 02/09/2024] [Accepted: 02/14/2024] [Indexed: 02/25/2024]
Abstract
(1) Background: Intracortical microelectrodes (IMEs) are an important part of interfacing with the central nervous system (CNS) and recording neural signals. However, recording electrodes have shown a characteristic steady decline in recording performance owing to chronic neuroinflammation. The topography of implanted devices has been explored to mimic the nanoscale three-dimensional architecture of the extracellular matrix. Our previous work used histology to study the implant sites of non-recording probes and showed that a nanoscale topography at the probe surface mitigated the neuroinflammatory response compared to probes with smooth surfaces. Here, we hypothesized that the improvement in the neuroinflammatory response for probes with nanoscale surface topography would extend to improved recording performance. (2) Methods: A novel design modification was implemented on planar silicon-based neural probes by etching nanopatterned grooves (with a 500 nm pitch) into the probe shank. To assess the hypothesis, two groups of rats were implanted with either nanopatterned (n = 6) or smooth control (n = 6) probes, and their recording performance was evaluated over 4 weeks. Postmortem gene expression analysis was performed to compare the neuroinflammatory response from the two groups. (3) Results: Nanopatterned probes demonstrated an increased impedance and noise floor compared to controls. However, the recording performances of the nanopatterned and smooth probes were similar, with active electrode yields for control probes and nanopatterned probes being approximately 50% and 45%, respectively, by 4 weeks post-implantation. Gene expression analysis showed one gene, Sirt1, differentially expressed out of 152 in the panel. (4) Conclusions: this study provides a foundation for investigating novel nanoscale topographies on neural probes.
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Affiliation(s)
- Jonathan L. Duncan
- Department of Biomedical Engineering, Case Western Reserve University, 10900 Euclid Ave, Cleveland, OH 44106, USA
- Advanced Platform Technology Center, Louis Stokes Cleveland Veterans Affairs Medical Center, 10701 East Blvd, Cleveland, OH 44106, USA
| | - Jaime J. Wang
- Department of Biomedical Engineering, Case Western Reserve University, 10900 Euclid Ave, Cleveland, OH 44106, USA
- Advanced Platform Technology Center, Louis Stokes Cleveland Veterans Affairs Medical Center, 10701 East Blvd, Cleveland, OH 44106, USA
| | - Gabriele Glusauskas
- Department of Biomedical Engineering, Case Western Reserve University, 10900 Euclid Ave, Cleveland, OH 44106, USA
- Advanced Platform Technology Center, Louis Stokes Cleveland Veterans Affairs Medical Center, 10701 East Blvd, Cleveland, OH 44106, USA
| | - Gwendolyn R. Weagraff
- Advanced Platform Technology Center, Louis Stokes Cleveland Veterans Affairs Medical Center, 10701 East Blvd, Cleveland, OH 44106, USA
| | - Yue Gao
- Department of Biomedical Engineering, Case Western Reserve University, 10900 Euclid Ave, Cleveland, OH 44106, USA
| | - George F. Hoeferlin
- Department of Biomedical Engineering, Case Western Reserve University, 10900 Euclid Ave, Cleveland, OH 44106, USA
- Advanced Platform Technology Center, Louis Stokes Cleveland Veterans Affairs Medical Center, 10701 East Blvd, Cleveland, OH 44106, USA
| | - Allen H. Hunter
- Michigan Center for Materials Characterization, University of Michigan, 500 S. State St, Ann Arbor, MI 48109, USA
| | - Allison Hess-Dunning
- Department of Biomedical Engineering, Case Western Reserve University, 10900 Euclid Ave, Cleveland, OH 44106, USA
- Advanced Platform Technology Center, Louis Stokes Cleveland Veterans Affairs Medical Center, 10701 East Blvd, Cleveland, OH 44106, USA
| | - Evon S. Ereifej
- Department of Biomedical Engineering, University of Michigan, 500 S. State St, Ann Arbor, MI 48109, USA
- Veterans Affairs Hospital, 2215 Fuller Rd, Ann Arbor, MI 48105, USA
| | - Jeffrey R. Capadona
- Department of Biomedical Engineering, Case Western Reserve University, 10900 Euclid Ave, Cleveland, OH 44106, USA
- Advanced Platform Technology Center, Louis Stokes Cleveland Veterans Affairs Medical Center, 10701 East Blvd, Cleveland, OH 44106, USA
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2
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Ziemba AM, Woodson MCC, Funnell JL, Wich D, Balouch B, Rende D, Amato DN, Bao J, Oprea I, Cao D, Bajalo N, Ereifej ES, Capadona JR, Palermo EF, Gilbert RJ. Development of a Slow-Degrading Polymerized Curcumin Coating for Intracortical Microelectrodes. ACS Appl Bio Mater 2023; 6:806-818. [PMID: 36749645 DOI: 10.1021/acsabm.2c00969] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Intracortical microelectrodes are used with brain-computer interfaces to restore lost limb function following nervous system injury. While promising, recording ability of intracortical microelectrodes diminishes over time due, in part, to neuroinflammation. As curcumin has demonstrated neuroprotection through anti-inflammatory activity, we fabricated a 300 nm-thick intracortical microelectrode coating consisting of a polyurethane copolymer of curcumin and polyethylene glycol (PEG), denoted as poly(curcumin-PEG1000 carbamate) (PCPC). The uniform PCPC coating reduced silicon wafer hardness by two orders of magnitude and readily absorbed water within minutes, demonstrating that the coating is soft and hydrophilic in nature. Using an in vitro release model, curcumin eluted from the PCPC coating into the supernatant over 1 week; the majority of the coating was intact after an 8-week incubation in buffer, demonstrating potential for longer term curcumin release and softness. Assessing the efficacy of PCPC within a rat intracortical microelectrode model in vivo, there were no significant differences in tissue inflammation, scarring, neuron viability, and myelin damage between the uncoated and PCPC-coated probes. As the first study to implant nonfunctional probes with a polymerized curcumin coating, we have demonstrated the biocompatibility of a PCPC coating and presented a starting point in the design of poly(pro-curcumin) polymers as coating materials for intracortical electrodes.
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Affiliation(s)
- Alexis M Ziemba
- Department of Biomedical Engineering, Rensselaer Polytechnic Institute, Troy 12180-3590, New York, United States.,Center for Biotechnology and Interdisciplinary Sciences, Rensselaer Polytechnic Institute, Troy 12180-3590, New York, United States.,Neuroscience Program, Department of Biological Sciences, Smith College, Northampton 01063, Massachusetts, United States
| | - Mary Clare Crochiere Woodson
- Department of Biomedical Engineering, Rensselaer Polytechnic Institute, Troy 12180-3590, New York, United States.,Center for Biotechnology and Interdisciplinary Sciences, Rensselaer Polytechnic Institute, Troy 12180-3590, New York, United States
| | - Jessica L Funnell
- Department of Biomedical Engineering, Rensselaer Polytechnic Institute, Troy 12180-3590, New York, United States.,Center for Biotechnology and Interdisciplinary Sciences, Rensselaer Polytechnic Institute, Troy 12180-3590, New York, United States
| | - Douglas Wich
- Department of Biomedical Engineering, Rensselaer Polytechnic Institute, Troy 12180-3590, New York, United States.,Center for Biotechnology and Interdisciplinary Sciences, Rensselaer Polytechnic Institute, Troy 12180-3590, New York, United States
| | - Bailey Balouch
- Center for Biotechnology and Interdisciplinary Sciences, Rensselaer Polytechnic Institute, Troy 12180-3590, New York, United States
| | - Deniz Rende
- Center for Materials, Devices, and Integrated Systems, Rensselaer Polytechnic Institute, 110 8th Street, Troy 12180-3590, New York, United States
| | - Dahlia N Amato
- Department of Materials Science and Engineering, Rensselaer Polytechnic Institute, Troy 12180-3590, New York, United States.,Center for Biotechnology and Interdisciplinary Sciences, Rensselaer Polytechnic Institute, Troy 12180-3590, New York, United States
| | - Jonathan Bao
- Center for Biotechnology and Interdisciplinary Sciences, Rensselaer Polytechnic Institute, Troy 12180-3590, New York, United States
| | - Ingrid Oprea
- Center for Biotechnology and Interdisciplinary Sciences, Rensselaer Polytechnic Institute, Troy 12180-3590, New York, United States
| | - Dominica Cao
- Neuroscience Program, Department of Biological Sciences, Smith College, Northampton 01063, Massachusetts, United States
| | - Neda Bajalo
- Center for Biotechnology and Interdisciplinary Sciences, Rensselaer Polytechnic Institute, Troy 12180-3590, New York, United States
| | - Evon S Ereifej
- Veteran Affairs Ann Arbor Healthcare System, Ann Arbor 48104, Michigan, United States.,Department of Biomedical Engineering, University of Michigan, Ann Arbor 48104, Michigan, United States.,Department of Neurology, University of Michigan, Ann Arbor 48104, Michigan, United States.,United States Advanced Platform Technology Center, Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland 44106, Ohio, United States
| | - Jeffrey R Capadona
- United States Advanced Platform Technology Center, Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland 44106, Ohio, United States.,Department of Biomedical Engineering, Case Western Reserve University, Cleveland 44106, Ohio, United States
| | - Edmund F Palermo
- Department of Materials Science and Engineering, Rensselaer Polytechnic Institute, Troy 12180-3590, New York, United States
| | - Ryan J Gilbert
- Department of Biomedical Engineering, Rensselaer Polytechnic Institute, Troy 12180-3590, New York, United States.,Center for Biotechnology and Interdisciplinary Sciences, Rensselaer Polytechnic Institute, Troy 12180-3590, New York, United States
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3
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Song S, Regan B, Ereifej ES, Chan ER, Capadona JR. Neuroinflammatory Gene Expression Analysis Reveals Pathways of Interest as Potential Targets to Improve the Recording Performance of Intracortical Microelectrodes. Cells 2022; 11:2348. [PMID: 35954192 PMCID: PMC9367362 DOI: 10.3390/cells11152348] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Revised: 07/22/2022] [Accepted: 07/26/2022] [Indexed: 02/04/2023] Open
Abstract
Intracortical microelectrodes are a critical component of brain-machine interface (BMI) systems. The recording performance of intracortical microelectrodes used for both basic neuroscience research and clinical applications of BMIs decreases over time, limiting the utility of the devices. The neuroinflammatory response to the microelectrode has been identified as a significant contributing factor to its performance. Traditionally, pathological assessment has been limited to a dozen or so known neuroinflammatory proteins, and only a few groups have begun to explore changes in gene expression following microelectrode implantation. Our initial characterization of gene expression profiles of the neuroinflammatory response to mice implanted with non-functional intracortical probes revealed many upregulated genes that could inform future therapeutic targets. Emphasis was placed on the most significant gene expression changes and genes involved in multiple innate immune sets, including Cd14, C3, Itgam, and Irak4. In previous studies, inhibition of Cluster of Differentiation 14 (Cd14) improved microelectrode performance for up to two weeks after electrode implantation, suggesting CD14 can be explored as a potential therapeutic target. However, all measures of improvements in signal quality and electrode performance lost statistical significance after two weeks. Therefore, the current study investigated the expression of genes in the neuroinflammatory pathway at the tissue-microelectrode interface in Cd14-/- mice to understand better how Cd14 inhibition was connected to temporary improvements in recording quality over the initial 2-weeks post-surgery, allowing for the identification of potential co-therapeutic targets that may work synergistically with or after CD14 inhibition to improve microelectrode performance.
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Affiliation(s)
- Sydney Song
- Department of Biomedical Engineering, Case Western Reserve University, 2071 Martin Luther King Jr. Drive, Cleveland, OH 44106, USA; (S.S.); (E.S.E.)
- Advanced Platform Technology Center, Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland, OH 44106, USA
| | - Brianna Regan
- Veteran Affairs Ann Arbor Healthcare System, Ann Arbor, MI 48105, USA;
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109, USA
| | - Evon S. Ereifej
- Department of Biomedical Engineering, Case Western Reserve University, 2071 Martin Luther King Jr. Drive, Cleveland, OH 44106, USA; (S.S.); (E.S.E.)
- Advanced Platform Technology Center, Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland, OH 44106, USA
- Veteran Affairs Ann Arbor Healthcare System, Ann Arbor, MI 48105, USA;
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109, USA
- Department of Neurology, University of Michigan, Ann Arbor, MI 48109, USA
| | - E. Ricky Chan
- Institute for Computational Biology, Case Western Reserve University, Cleveland, OH 44106, USA;
| | - Jeffrey R. Capadona
- Department of Biomedical Engineering, Case Western Reserve University, 2071 Martin Luther King Jr. Drive, Cleveland, OH 44106, USA; (S.S.); (E.S.E.)
- Advanced Platform Technology Center, Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland, OH 44106, USA
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4
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Kim Y, Ereifej ES, Schwartzman WE, Meade SM, Chen K, Rayyan J, Feng H, Aluri V, Mueller NN, Bhambra R, Bhambra S, Taylor DM, Capadona JR. Investigation of the Feasibility of Ventricular Delivery of Resveratrol to the Microelectrode Tissue Interface. Micromachines (Basel) 2021; 12:1446. [PMID: 34945296 PMCID: PMC8708660 DOI: 10.3390/mi12121446] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Revised: 11/12/2021] [Accepted: 11/19/2021] [Indexed: 12/02/2022]
Abstract
(1) Background: Intracortical microelectrodes (IMEs) are essential to basic brain research and clinical brain-machine interfacing applications. However, the foreign body response to IMEs results in chronic inflammation and an increase in levels of reactive oxygen and nitrogen species (ROS/RNS). The current study builds on our previous work, by testing a new delivery method of a promising antioxidant as a means of extending intracortical microelectrodes performance. While resveratrol has shown efficacy in improving tissue response, chronic delivery has proven difficult because of its low solubility in water and low bioavailability due to extensive first pass metabolism. (2) Methods: Investigation of an intraventricular delivery of resveratrol in rats was performed herein to circumvent bioavailability hurdles of resveratrol delivery to the brain. (3) Results: Intraventricular delivery of resveratrol in rats delivered resveratrol to the electrode interface. However, intraventricular delivery did not have a significant impact on electrophysiological recordings over the six-week study. Histological findings indicated that rats receiving intraventricular delivery of resveratrol had a decrease of oxidative stress, yet other biomarkers of inflammation were found to be not significantly different from control groups. However, investigation of the bioavailability of resveratrol indicated a decrease in resveratrol accumulation in the brain with time coupled with inconsistent drug elution from the cannulas. Further inspection showed that there may be tissue or cellular debris clogging the cannulas, resulting in variable elution, which may have impacted the results of the study. (4) Conclusions: These results indicate that the intraventricular delivery approach described herein needs further optimization, or may not be well suited for this application.
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Affiliation(s)
- Youjoung Kim
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH 44106, USA
- Advanced Platform Technology Center, Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland, OH 44106, USA
| | - Evon S. Ereifej
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH 44106, USA
- Advanced Platform Technology Center, Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland, OH 44106, USA
- Veteran Affairs Ann Arbor Healthcare System, Ann Arbor, MI 48105, USA
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109, USA
- Department of Neurology, University of Michigan, Ann Arbor, MI 48109, USA
| | - William E. Schwartzman
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH 44106, USA
- Advanced Platform Technology Center, Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland, OH 44106, USA
| | - Seth M. Meade
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH 44106, USA
- Advanced Platform Technology Center, Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland, OH 44106, USA
| | - Keying Chen
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH 44106, USA
- Advanced Platform Technology Center, Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland, OH 44106, USA
| | - Jacob Rayyan
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH 44106, USA
- Advanced Platform Technology Center, Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland, OH 44106, USA
| | - He Feng
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH 44106, USA
- Advanced Platform Technology Center, Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland, OH 44106, USA
| | - Varoon Aluri
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH 44106, USA
- Advanced Platform Technology Center, Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland, OH 44106, USA
| | - Natalie N. Mueller
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH 44106, USA
- Advanced Platform Technology Center, Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland, OH 44106, USA
| | - Raman Bhambra
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH 44106, USA
- Advanced Platform Technology Center, Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland, OH 44106, USA
| | - Sahaj Bhambra
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH 44106, USA
- Advanced Platform Technology Center, Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland, OH 44106, USA
| | - Dawn M. Taylor
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH 44106, USA
- Advanced Platform Technology Center, Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland, OH 44106, USA
- Cleveland Functional Electrical Stimulation Center, Louis Stokes Cleveland Veterans Affairs Medical Center, Rehabilitation Research and Development, Cleveland, OH 44106, USA
- Department of Neurosciences, Cleveland Clinic Lerner Research Institute, Cleveland, OH 44195, USA
| | - Jeffrey R. Capadona
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH 44106, USA
- Advanced Platform Technology Center, Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland, OH 44106, USA
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5
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Haley RM, Zuckerman ST, Dakhlallah H, Capadona JR, von Recum HA, Ereifej ES. Resveratrol Delivery from Implanted Cyclodextrin Polymers Provides Sustained Antioxidant Effect on Implanted Neural Probes. Int J Mol Sci 2020; 21:ijms21103579. [PMID: 32438593 PMCID: PMC7279014 DOI: 10.3390/ijms21103579] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Revised: 05/08/2020] [Accepted: 05/15/2020] [Indexed: 12/12/2022] Open
Abstract
Intracortical microelectrodes are valuable tools used to study and treat neurological diseases. Due in large part to the oxidative stress and inflammatory response occurring after electrode implantation, the signal quality of these electrodes decreases over time. To alleviate this response, resveratrol, a natural antioxidant which elicits neuroprotective effects through reduction of oxidative stress, was utilized. This work compares traditional systemic delivery of resveratrol to the novel cyclodextrin polymer (pCD) local delivery approach presented herein, both in vitro and in vivo. The pCD displayed an extended resveratrol release for 100 days, as well as 60 days of free radical scavenging activity in vitro. In vivo results indicated that our pCD delivery system successfully delivered resveratrol to the brain with a sustained release for the entire short-duration study (up to 7 days). Interestingly, significantly greater concentrations of resveratrol metabolites were found at the intracortical probe implantation site compared to the systemic administration of resveratrol. Together, our pilot results provide support for the possibility of improving the delivery of resveratrol in an attempt to stabilize long-term neural interfacing applications.
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Affiliation(s)
- Rebecca M. Haley
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH 44106, USA; (R.M.H.); (J.R.C.)
| | - Sean T. Zuckerman
- Affinity Therapeutics, LLC, 11000 Cedar Avenue, Suite 285, Cleveland, OH 44106, USA;
| | - Hassan Dakhlallah
- Veteran Affairs Ann Arbor Healthcare System, Ann Arbor, MI 48105, USA;
| | - Jeffery R. Capadona
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH 44106, USA; (R.M.H.); (J.R.C.)
- Advanced Platform Technology Center, Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland, OH 44106, USA
| | - Horst A. von Recum
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH 44106, USA; (R.M.H.); (J.R.C.)
- Advanced Platform Technology Center, Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland, OH 44106, USA
- Correspondence: (H.A.v.R.); (E.S.E.)
| | - Evon S. Ereifej
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH 44106, USA; (R.M.H.); (J.R.C.)
- Veteran Affairs Ann Arbor Healthcare System, Ann Arbor, MI 48105, USA;
- Advanced Platform Technology Center, Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland, OH 44106, USA
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109, USA
- Department of Neurology, University of Michigan, Ann Arbor, MI 48109, USA
- Correspondence: (H.A.v.R.); (E.S.E.)
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6
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Mahajan S, Hermann JK, Bedell HW, Sharkins JA, Chen L, Chen K, Meade SM, Smith CS, Rayyan J, Feng H, Kim Y, Schiefer MA, Taylor DM, Capadona JR, Ereifej ES. Toward Standardization of Electrophysiology and Computational Tissue Strain in Rodent Intracortical Microelectrode Models. Front Bioeng Biotechnol 2020; 8:416. [PMID: 32457888 PMCID: PMC7225268 DOI: 10.3389/fbioe.2020.00416] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Accepted: 04/14/2020] [Indexed: 12/26/2022] Open
Abstract
Progress has been made in the field of neural interfacing using both mouse and rat models, yet standardization of these models' interchangeability has yet to be established. The mouse model allows for transgenic, optogenetic, and advanced imaging modalities which can be used to examine the biological impact and failure mechanisms associated with the neural implant itself. The ability to directly compare electrophysiological data between mouse and rat models is crucial for the development and assessment of neural interfaces. The most obvious difference in the two rodent models is size, which raises concern for the role of device-induced tissue strain. Strain exerted on brain tissue by implanted microelectrode arrays is hypothesized to affect long-term recording performance. Therefore, understanding any potential differences in tissue strain caused by differences in the implant to tissue size ratio is crucial for validating the interchangeability of rat and mouse models. Hence, this study is aimed at investigating the electrophysiological variances and predictive device-induced tissue strain. Rat and mouse electrophysiological recordings were collected from implanted animals for eight weeks. A finite element model was utilized to assess the tissue strain from implanted intracortical microelectrodes, taking into account the differences in the depth within the cortex, implantation depth, and electrode geometry between the two models. The rat model demonstrated a larger percentage of channels recording single unit activity and number of units recorded per channel at acute but not chronic time points, relative to the mouse model Additionally, the finite element models also revealed no predictive differences in tissue strain between the two rodent models. Collectively our results show that these two models are comparable after taking into consideration some recommendations to maintain uniform conditions for future studies where direct comparisons of electrophysiological and tissue strain data between the two animal models will be required.
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Affiliation(s)
- Shreya Mahajan
- Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, MI, United States
| | - John K. Hermann
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States
- Advanced Platform Technology Center, Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland, OH, United States
| | - Hillary W. Bedell
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States
- Advanced Platform Technology Center, Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland, OH, United States
| | - Jonah A. Sharkins
- Veteran Affairs Ann Arbor Healthcare System, Ann Arbor, MI, United States
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, United States
| | - Lei Chen
- Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI, United States
| | - Keying Chen
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States
- Advanced Platform Technology Center, Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland, OH, United States
| | - Seth M. Meade
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States
- Advanced Platform Technology Center, Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland, OH, United States
| | - Cara S. Smith
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States
- Advanced Platform Technology Center, Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland, OH, United States
| | - Jacob Rayyan
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States
- Advanced Platform Technology Center, Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland, OH, United States
| | - He Feng
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States
- Advanced Platform Technology Center, Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland, OH, United States
| | - Youjoung Kim
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States
- Advanced Platform Technology Center, Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland, OH, United States
| | - Matthew A. Schiefer
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States
- Advanced Platform Technology Center, Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland, OH, United States
| | - Dawn M. Taylor
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States
- Advanced Platform Technology Center, Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland, OH, United States
- Department of Neuroscience, The Cleveland Clinic, Cleveland, OH, United States
| | - Jeffrey R. Capadona
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States
- Advanced Platform Technology Center, Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland, OH, United States
| | - Evon S. Ereifej
- Advanced Platform Technology Center, Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland, OH, United States
- Veteran Affairs Ann Arbor Healthcare System, Ann Arbor, MI, United States
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, United States
- Department of Neurology, University of Michigan, Ann Arbor, MI, United States
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7
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Abstract
With advances in electronics and fabrication technology, intracortical microelectrodes have undergone substantial improvements enabling the production of sophisticated microelectrodes with greater resolution and expanded capabilities. The progress in fabrication technology has supported the development of biomimetic electrodes, which aim to seamlessly integrate into the brain parenchyma, reduce the neuroinflammatory response observed after electrode insertion and improve the quality and longevity of electrophysiological recordings. Here we describe a protocol to employ a biomimetic approach recently classified as nano-architecture. The use of focused ion beam lithography (FIB) was utilized in this protocol to etch specific nano-architecture features into the surface of non-functional and functional single shank intracortical microelectrodes. Etching nano-architectures into the electrode surface indicated possible improvements of biocompatibility and functionality of the implanted device. One of the benefits of using FIB is the ability to etch on manufactured devices, as opposed to during the fabrication of the device, facilitating boundless possibilities to modify numerous medical devices post-manufacturing. The protocol presented herein can be optimized for various material types, nano-architecture features, and types of devices. Augmenting the surface of implanted medical devices can improve the device performance and integration into the tissue.
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Affiliation(s)
- Shreya Mahajan
- Department of Electrical Engineering and Computer Science, University of Michigan
| | - Jonah A Sharkins
- Veteran Affairs Ann Arbor Healthcare System; Department of Biomedical Engineering, University of Michigan
| | - Allen H Hunter
- Michigan Center for Materials Characterization, University of Michigan
| | | | - Evon S Ereifej
- Veteran Affairs Ann Arbor Healthcare System; Department of Neurology, School of Medicine, University of Michigan; Department of Biomedical Engineering, University of Michigan;
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8
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Bedell HW, Schaub NJ, Capadona JR, Ereifej ES. Differential expression of genes involved in the acute innate immune response to intracortical microelectrodes. Acta Biomater 2020; 102:205-219. [PMID: 31733330 DOI: 10.1016/j.actbio.2019.11.017] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2019] [Revised: 11/06/2019] [Accepted: 11/07/2019] [Indexed: 02/07/2023]
Abstract
Higher order tasks in development for brain-computer interfacing applications require the invasiveness of intracortical microelectrodes. Unfortunately, the resulting inflammatory response contributes to the decline of detectable neural signal. The major components of the neuroinflammatory response to microelectrodes have been well-documented with histological imaging, leading to the identification of broad pathways of interest for its inhibition such as oxidative stress and innate immunity. To understand how to mitigate the neuroinflammatory response, a more precise understanding is required. Advancements in genotyping have led the development of new tools for developing temporal gene expression profiles. Therefore, we have meticulously characterized the gene expression profiles of the neuroinflammatory response to mice implanted with non-functional intracortical probes. A time course of differential acute expression of genes of the innate immune response were compared to naïve sham mice, identifying significant changes following implantation. Differential gene expression analysis revealed 22 genes that could inform future therapeutic targets. Particular emphasis is placed on the largest changes in gene expression occurring 24 h post-implantation, and in genes that are involved in multiple innate immune sets including Itgam, Cd14, and Irak4. STATEMENT OF SIGNIFICANCE: Current understanding of the cellular response contributing to the failure of intracortical microelectrodes has been limited to the evaluation of cellular presence around the electrode. Minimal research investigating gene expression profiles of these cells has left a knowledge gap identifying their phenotype. This manuscript represents the first robust investigation of the changes in gene expression levels specific to the innate immune response following intracortical microelectrode implantation. To understand the role of the complement system in response to implanted probes, we performed gene expression profiling over acute time points from implanted subjects and compared them to no-surgery controls. This manuscript provides valuable insights into inflammatory mechanisms at the tissue-probe interface, thus having a high impact on those using intracortical microelectrodes to study and treat neurological diseases and injuries.
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Ereifej ES, Shell CE, Schofield JS, Charkhkar H, Cuberovic I, Dorval AD, Graczyk EL, Kozai TDY, Otto KJ, Tyler DJ, Welle CG, Widge AS, Zariffa J, Moritz CT, Bourbeau DJ, Marasco PD. Neural engineering: the process, applications, and its role in the future of medicine. J Neural Eng 2019; 16:063002. [PMID: 31557730 DOI: 10.1088/1741-2552/ab4869] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
OBJECTIVE Recent advances in neural engineering have restored mobility to people with paralysis, relieved symptoms of movement disorders, reduced chronic pain, restored the sense of hearing, and provided sensory perception to individuals with sensory deficits. APPROACH This progress was enabled by the team-based, interdisciplinary approaches used by neural engineers. Neural engineers have advanced clinical frontiers by leveraging tools and discoveries in quantitative and biological sciences and through collaborations between engineering, science, and medicine. The movement toward bioelectronic medicines, where neuromodulation aims to supplement or replace pharmaceuticals to treat chronic medical conditions such as high blood pressure, diabetes and psychiatric disorders is a prime example of a new frontier made possible by neural engineering. Although one of the major goals in neural engineering is to develop technology for clinical applications, this technology may also offer unique opportunities to gain insight into how biological systems operate. MAIN RESULTS Despite significant technological progress, a number of ethical and strategic questions remain unexplored. Addressing these questions will accelerate technology development to address unmet needs. The future of these devices extends far beyond treatment of neurological impairments, including potential human augmentation applications. Our task, as neural engineers, is to push technology forward at the intersection of disciplines, while responsibly considering the readiness to transition this technology outside of the laboratory to consumer products. SIGNIFICANCE This article aims to highlight the current state of the neural engineering field, its links with other engineering and science disciplines, and the challenges and opportunities ahead. The goal of this article is to foster new ideas for innovative applications in neurotechnology.
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Affiliation(s)
- Evon S Ereifej
- Veteran Affairs Ann Arbor Healthcare System, Ann Arbor, MI, United States of America. Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, United States of America. Department of Neurology, University of Michigan, Ann Arbor, MI, United States of America. Advanced Platform Technology Center, Louis Stokes Cleveland VA Medical Center, Cleveland, OH, United States of America
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10
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Hermann JK, Ravikumar M, Shoffstall AJ, Ereifej ES, Kovach KM, Chang J, Soffer A, Wong C, Srivastava V, Smith P, Protasiewicz G, Jiang J, Selkirk SM, Miller RH, Sidik S, Ziats NP, Taylor DM, Capadona JR. Inhibition of the cluster of differentiation 14 innate immunity pathway with IAXO-101 improves chronic microelectrode performance. J Neural Eng 2019; 15:025002. [PMID: 29219114 DOI: 10.1088/1741-2552/aaa03e] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
OBJECTIVE Neuroinflammatory mechanisms are hypothesized to contribute to intracortical microelectrode failures. The cluster of differentiation 14 (CD14) molecule is an innate immunity receptor involved in the recognition of pathogens and tissue damage to promote inflammation. The goal of the study was to investigate the effect of CD14 inhibition on intracortical microelectrode recording performance and tissue integration. APPROACH Mice implanted with intracortical microelectrodes in the motor cortex underwent electrophysiological characterization for 16 weeks, followed by endpoint histology. Three conditions were examined: (1) wildtype control mice, (2) knockout mice lacking CD14, and (3) wildtype control mice administered a small molecule inhibitor to CD14 called IAXO-101. MAIN RESULTS The CD14 knockout mice exhibited acute but not chronic improvements in intracortical microelectrode performance without significant differences in endpoint histology. Mice receiving IAXO-101 exhibited significant improvements in recording performance over the entire 16 week duration without significant differences in endpoint histology. SIGNIFICANCE Full removal of CD14 is beneficial at acute time ranges, but limited CD14 signaling is beneficial at chronic time ranges. Innate immunity receptor inhibition strategies have the potential to improve long-term intracortical microelectrode performance.
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Affiliation(s)
- John K Hermann
- Advanced Platform Technology Center, Louis Stokes Cleveland Department of Veterans Affairs Medical Center, Rehabilitation Research and Development, 10701 East Blvd. Mail Stop 151 AW/APT, Cleveland OH 44106, United States of America. Department of Biomedical Engineering, Case Western Reserve University, School of Engineering, 2071 Martin Luther King Jr Drive, Wickenden Bldg, Cleveland OH 44106, United States of America
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11
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Goss-Varley M, Shoffstall AJ, Dona KR, McMahon JA, Lindner SC, Ereifej ES, Capadona JR. Rodent Behavioral Testing to Assess Functional Deficits Caused by Microelectrode Implantation in the Rat Motor Cortex. J Vis Exp 2018:57829. [PMID: 30176008 PMCID: PMC6128113 DOI: 10.3791/57829] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Medical devices implanted in the brain hold tremendous potential. As part of a Brain Machine Interface (BMI) system, intracortical microelectrodes demonstrate the ability to record action potentials from individual or small groups of neurons. Such recorded signals have successfully been used to allow patients to interface with or control computers, robotic limbs, and their own limbs. However, previous animal studies have shown that a microelectrode implantation in the brain not only damages the surrounding tissue but can also result in functional deficits. Here, we discuss a series of behavioral tests to quantify potential motor impairments following the implantation of intracortical microelectrodes into the motor cortex of a rat. The methods for open field grid, ladder crossing, and grip strength testing provide valuable information regarding the potential complications resulting from a microelectrode implantation. The results of the behavioral testing are correlated with endpoint histology, providing additional information on the pathological outcomes and impacts of this procedure on the adjacent tissue.
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Affiliation(s)
- Monika Goss-Varley
- Advanced Platform Technology Center, Rehabilitation Research and Development, Louis Stokes Cleveland Department of Veterans Affairs Medical Center; Department of Biomedical Engineering, Case Western Reserve University
| | - Andrew J Shoffstall
- Advanced Platform Technology Center, Rehabilitation Research and Development, Louis Stokes Cleveland Department of Veterans Affairs Medical Center; Department of Biomedical Engineering, Case Western Reserve University
| | - Keith R Dona
- Advanced Platform Technology Center, Rehabilitation Research and Development, Louis Stokes Cleveland Department of Veterans Affairs Medical Center; Department of Biomedical Engineering, Case Western Reserve University
| | - Justin A McMahon
- Advanced Platform Technology Center, Rehabilitation Research and Development, Louis Stokes Cleveland Department of Veterans Affairs Medical Center; Department of Biomedical Engineering, Case Western Reserve University
| | - Sydney C Lindner
- Advanced Platform Technology Center, Rehabilitation Research and Development, Louis Stokes Cleveland Department of Veterans Affairs Medical Center; Department of Biomedical Engineering, Case Western Reserve University
| | - Evon S Ereifej
- Advanced Platform Technology Center, Rehabilitation Research and Development, Louis Stokes Cleveland Department of Veterans Affairs Medical Center; Department of Biomedical Engineering, Case Western Reserve University
| | - Jeffrey R Capadona
- Advanced Platform Technology Center, Rehabilitation Research and Development, Louis Stokes Cleveland Department of Veterans Affairs Medical Center; Department of Biomedical Engineering, Case Western Reserve University;
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Kim Y, Meade SM, Chen K, Feng H, Rayyan J, Hess-Dunning A, Ereifej ES. Nano-Architectural Approaches for Improved Intracortical Interface Technologies. Front Neurosci 2018; 12:456. [PMID: 30065623 PMCID: PMC6056633 DOI: 10.3389/fnins.2018.00456] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Accepted: 06/14/2018] [Indexed: 12/19/2022] Open
Abstract
Intracortical microelectrodes (IME) are neural devices that initially were designed to function as neuroscience tools to enable researchers to understand the nervous system. Over the years, technology that aids interfacing with the nervous system has allowed the ability to treat patients with a wide range of neurological injuries and diseases. Despite the substantial success that has been demonstrated using IME in neural interface applications, these implants eventually fail due to loss of quality recording signals. Recent strategies to improve interfacing with the nervous system have been inspired by methods that mimic the native tissue. This review focusses on one strategy in particular, nano-architecture, a term we introduce that encompasses the approach of roughening the surface of the implant. Various nano-architecture approaches have been hypothesized to improve the biocompatibility of IMEs, enhance the recording quality, and increase the longevity of the implant. This review will begin by introducing IME technology and discuss the challenges facing the clinical deployment of IME technology. The biological inspiration of nano-architecture approaches will be explained as well as leading fabrication methods used to create nano-architecture and their limitations. A review of the effects of nano-architecture surfaces on neural cells will be examined, depicting the various cellular responses to these modified surfaces in both in vitro and pre-clinical models. The proposed mechanism elucidating the ability of nano-architectures to influence cellular phenotype will be considered. Finally, the frontiers of next generation nano-architecture IMEs will be identified, with perspective given on the future impact of this interfacing approach.
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Affiliation(s)
- Youjoung Kim
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States
- Advanced Platform Technology Center, Louis Stokes Cleveland Department of Veterans Affairs Medical Center, Cleveland, OH, United States
| | - Seth M. Meade
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States
- Advanced Platform Technology Center, Louis Stokes Cleveland Department of Veterans Affairs Medical Center, Cleveland, OH, United States
| | - Keying Chen
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States
- Advanced Platform Technology Center, Louis Stokes Cleveland Department of Veterans Affairs Medical Center, Cleveland, OH, United States
| | - He Feng
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States
- Advanced Platform Technology Center, Louis Stokes Cleveland Department of Veterans Affairs Medical Center, Cleveland, OH, United States
| | - Jacob Rayyan
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States
- Advanced Platform Technology Center, Louis Stokes Cleveland Department of Veterans Affairs Medical Center, Cleveland, OH, United States
| | - Allison Hess-Dunning
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States
- Advanced Platform Technology Center, Louis Stokes Cleveland Department of Veterans Affairs Medical Center, Cleveland, OH, United States
| | - Evon S. Ereifej
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States
- Advanced Platform Technology Center, Louis Stokes Cleveland Department of Veterans Affairs Medical Center, Cleveland, OH, United States
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13
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Ereifej ES, Rial GM, Hermann JK, Smith CS, Meade SM, Rayyan JM, Chen K, Feng H, Capadona JR. Implantation of Neural Probes in the Brain Elicits Oxidative Stress. Front Bioeng Biotechnol 2018; 6:9. [PMID: 29487848 PMCID: PMC5816578 DOI: 10.3389/fbioe.2018.00009] [Citation(s) in RCA: 61] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Accepted: 01/22/2018] [Indexed: 12/11/2022] Open
Abstract
Clinical implantation of intracortical microelectrodes has been hindered, at least in part, by the perpetual inflammatory response occurring after device implantation. The neuroinflammatory response observed after device implantation has been correlated to oxidative stress that occurs due to neurological injury and disease. However, there has yet to be a definitive link of oxidative stress to intracortical microelectrode implantation. Thus, the objective of this study is to give direct evidence of oxidative stress following intracortical microelectrode implantation. This study also aims to identify potential molecular targets to attenuate oxidative stress observed postimplantation. Here, we implanted adult rats with silicon non-functional microelectrode probes for 4 weeks and compared the oxidative stress response to no surgery controls through postmortem gene expression analysis and qualitative histological observation of oxidative stress markers. Gene expression analysis results at 4 weeks postimplantation indicated that EH domain-containing 2, prion protein gene (Prnp), and Stearoyl-Coenzyme A desaturase 1 (Scd1) were all significantly higher for animals implanted with intracortical microelectrode probes compared to no surgery control animals. To the contrary, NADPH oxidase activator 1 (Noxa1) relative gene expression was significantly lower for implanted animals compared to no surgery control animals. Histological observation of oxidative stress showed an increased expression of oxidized proteins, lipids, and nucleic acids concentrated around the implant site. Collectively, our results reveal there is a presence of oxidative stress following intracortical microelectrode implantation compared to no surgery controls. Further investigation targeting these specific oxidative stress linked genes could be beneficial to understanding potential mechanisms and downstream therapeutics that can be utilized to reduce oxidative stress-mediated damage following microelectrode implantation.
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Affiliation(s)
- Evon S. Ereifej
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States
- Advanced Platform Technology Center, Louis Stokes Cleveland Department of Veterans Affairs Medical Center, Cleveland, OH, United States
| | - Griffin M. Rial
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States
- Advanced Platform Technology Center, Louis Stokes Cleveland Department of Veterans Affairs Medical Center, Cleveland, OH, United States
| | - John K. Hermann
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States
- Advanced Platform Technology Center, Louis Stokes Cleveland Department of Veterans Affairs Medical Center, Cleveland, OH, United States
| | - Cara S. Smith
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States
- Advanced Platform Technology Center, Louis Stokes Cleveland Department of Veterans Affairs Medical Center, Cleveland, OH, United States
| | - Seth M. Meade
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States
- Advanced Platform Technology Center, Louis Stokes Cleveland Department of Veterans Affairs Medical Center, Cleveland, OH, United States
| | - Jacob M. Rayyan
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States
- Advanced Platform Technology Center, Louis Stokes Cleveland Department of Veterans Affairs Medical Center, Cleveland, OH, United States
| | - Keying Chen
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States
- Advanced Platform Technology Center, Louis Stokes Cleveland Department of Veterans Affairs Medical Center, Cleveland, OH, United States
| | - He Feng
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States
- Advanced Platform Technology Center, Louis Stokes Cleveland Department of Veterans Affairs Medical Center, Cleveland, OH, United States
| | - Jeffrey R. Capadona
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States
- Advanced Platform Technology Center, Louis Stokes Cleveland Department of Veterans Affairs Medical Center, Cleveland, OH, United States
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14
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Ereifej ES, Khan S, Newaz G, Zhang J, Auner GW, VandeVord PJ. Comparative assessment of iridium oxide and platinum alloy wires using an in vitro glial scar assay. Biomed Microdevices 2014; 15:917-24. [PMID: 23764951 DOI: 10.1007/s10544-013-9780-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The long-term effect of chronically implanted electrodes is the formation of a glial scar. Therefore, it is imperative to assess the biocompatibility of materials before employing them in neural electrode fabrication. Platinum alloy and iridium oxide have been identified as good candidates as neural electrode biomaterials due to their mechanical and electrical properties, however, effect of glial scar formation for these two materials is lacking. In this study, we applied a glial scarring assay to observe the cellular reactivity to platinum alloy and iridium oxide wires in order to assess the biocompatibility based on previously defined characteristics. Through real-time PCR, immunostaining and imaging techniques, we will advance the understanding of the biocompatibility of these materials. Results of this study demonstrate iridium oxide wires exhibited a more significant reactive response as compared to platinum alloy wires. Cells cultured with platinum alloy wires had less GFAP gene expression, lower average GFAP intensity, and smaller glial scar thickness. Collectively, these results indicated that platinum alloy wires were more biocompatible than the iridium oxide wires.
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Affiliation(s)
- Evon S Ereifej
- Department of Biomedical Engineering, Wayne State University, Detroit, MI, USA
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15
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Sajja VSSS, Ereifej ES, VandeVord PJ. Hippocampal vulnerability and subacute response following varied blast magnitudes. Neurosci Lett 2014; 570:33-7. [PMID: 24726403 DOI: 10.1016/j.neulet.2014.03.072] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2014] [Revised: 03/27/2014] [Accepted: 03/28/2014] [Indexed: 11/16/2022]
Abstract
Clinical outcomes from blast neurotrauma are associated with higher order cognitive functions such as memory, problem solving skills and attention. Current literature is limited to a single overpressure exposure or repeated exposures at the same level of overpressure and is focused on the acute response (<3 days). In an attempt to expand the understanding of neuropathological and molecular changes of the subacute response (7 days post injury), we used an established rodent model of blast neurotrauma. Three pressure magnitudes (low, moderate and high) were used to evaluate molecular injury thresholds. Immunohistochemical analysis demonstrated increased cleaved caspase-3 levels and loss of neuronal population (NeuN+) within the hippocampus of all pressure groups. On the contrary, selective activation of microglia was observed in the low blast group. In addition, increased astrocytes (GFAP), membrane signal transduction protein (Map2k1) and calcium regulator mechanosensitive protein (Piezo 2) were observed in the moderate blast group. Results from gene expression analysis suggested ongoing neuroprotection, as brain-derived neurotrophic factor (BDNF), glial-derived neurotrophic factor (GDNF) and Mn and CuZn superoxide dismutases (SOD) all increased in the low and moderate blast groups. Ongoing neuroprotection was further supported by increased SOD levels observed in the moderate group using immunohistochemistry. The gene expression level of glutamate aspartate transporter (GLAST) was upregulated in the low, but downregulated in the high blast group, while no changes were found in the moderate group. Overall, the data shown here provides evidence of a diverse neuroprotective and glial response to various levels of blast exposure. This mechanistic role of neuroprotection is vital in understanding ongoing cellular stress, both at the gene and protein levels, in order to develop interventional studies for the prognosis of injury.
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Affiliation(s)
| | - Evon S Ereifej
- School of Biomedical Engineering and Sciences, Virginia Polytechnic and State University, Blacksburg, VA, USA
| | - Pamela J VandeVord
- School of Biomedical Engineering and Sciences, Virginia Polytechnic and State University, Blacksburg, VA, USA; Salem VA Medical Center, Research & Development Service, Salem, VA, USA.
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16
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Ereifej ES, Cheng MMC, Mao G, VandeVord PJ. Examining the inflammatory response to nanopatterned polydimethylsiloxane using organotypic brain slice methods. J Neurosci Methods 2013; 217:17-25. [DOI: 10.1016/j.jneumeth.2013.04.023] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2013] [Revised: 04/23/2013] [Accepted: 04/25/2013] [Indexed: 12/18/2022]
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17
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Ereifej ES, Matthew HW, Newaz G, Mukhopadhyay A, Auner G, Salakhutdinov I, VandeVord PJ. Nanopatterning effects on astrocyte reactivity. J Biomed Mater Res A 2012. [PMID: 23184878 DOI: 10.1002/jbm.a.34480] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
An array of design strategies have been targeted toward minimizing failure of implanted microelectrodes by minimizing the chronic glial scar around the microelectrode under chronic conditions. Current approaches toward inhibiting the initiation of glial scarring range from altering the geometry, roughness, size, shape, and materials of the device. Studies have shown materials which mimic the nanotopography of the natural environment in vivo will consequently result in an improved biocompatible response. Nanofabrication of electrode arrays is being pursued in the field of neuronal electrophysiology to increase sampling capabilities. Literature shows a gap in research of nanotopography influence in the reduction of astrogliosis. The aim of this study was to determine optimal feature sizes for neural electrode fabrication, which was defined as eliciting a nonreactive astrocytic response. Nanopatterned surfaces were fabricated with nanoimprint lithography on poly(methyl methacrylate) surfaces. The rate of protein adsorption, quantity of protein adsorption, cell alignment, morphology, adhesion, proliferation, viability, and gene expression was compared between nanopatterned surfaces of different dimensions and non-nanopatterned control surfaces. Results of this study revealed that 3600 nanopatterned surfaces elicited less of a response when compared with the other patterned and non-nanopatterned surfaces. The surface instigated cell alignment along the nanopattern, less protein adsorption, less cell adhesion, proliferation and viability, inhibition of glial fibrillary acidic protein, and mitogen-activated protein kinase kinase 1 compared with all other substrates tested.
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Affiliation(s)
- Evon S Ereifej
- Department of Biomedical Engineering, Wayne State University, Detroit, Michigan, USA
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18
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Ereifej ES, Khan S, Newaz G, Zhang J, Auner GW, VandeVord PJ. Characterization of astrocyte reactivity and gene expression on biomaterials for neural electrodes. J Biomed Mater Res A 2011; 99:141-50. [PMID: 21812095 DOI: 10.1002/jbm.a.33170] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2010] [Revised: 02/15/2011] [Accepted: 04/29/2011] [Indexed: 01/06/2023]
Abstract
Neural electrode devices hold great promise to help people with the restoration of lost functions. However, research is lacking in the biomaterial design of a stable, long-term device. Glial scarring is initiated when a device is inserted into brain tissue and an inflammatory response ensues. Astrocytes become hypertrophic, hyperplastic, and upregulate glial-fibrillary acidic protein. This study was designed to investigate the astrocyte proliferation, viability, morphology, and gene expression to assess the reactive state of the cells on different material surfaces. Although platinum and silicon have been extensively characterized both in vivo and in vitro for their biocompatibility with neuronal cells, this study used the novel usage of PMMA and SU-8 in neural electrodes by comparative analysis of materials' biocompatibility. This study has shown evidence of noncytotoxicity of SU-8. We have also confirmed the biocompatibility of PMMA with astrocytes. Moreover, we have established sound guidelines of which neural implant materials should meet to be depicted biocompatible.
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Affiliation(s)
- Evon S Ereifej
- Department of Biomedical Engineering, Wayne State University, Detroit, Michigan, USA
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Trivedi V, Ereifej ES, Doshi A, Sehgal P, Vandevord PJ, Basu AS. Microfluidic encapsulation of cells in alginate capsules for high throughput screening. Annu Int Conf IEEE Eng Med Biol Soc 2010; 2009:7037-40. [PMID: 19964195 DOI: 10.1109/iembs.2009.5333308] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Microdroplet systems can drastically reduce costs and increase throughput in high throughput screening (HTS) assays. While droplets are well suited for biomolecular screening, cell-based screens are more problematic because eukaryotes typically require attachment to solid supports to maintain viability and function. This paper describes an economical, off-the-shelf microfluidic system which encapsulates eukaryotic cells in gelatinous alginate capsules for the purpose of HTS. The flow-through system consists of i) a cross junction, which forms monodisperse droplets of alginate and cell suspension in an immiscible carrier fluid, followed by ii) a T junction which delivers BaCl(2) to crosslink and solidify each droplet. With an appropriate carrier fluid, the system is self-synchronized and can produce cell-alginate-BaCl(2) capsules with virtually 100% reliability. Droplet volumes and frequency are determined by flow rates and the diameter of the cross junction. The present implementation, which utilizes 1.5 mm Teflon tubing and plastic junctions, can generate 0.4-1.4 microL droplets at frequencies >10 droplets/sec. Cell viability is >80% at 4 hours post-encapsulation. With low recurring cost (<USD 2) and no need for automation robots, this can be an initial step towards economical cell-based HTS.
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Affiliation(s)
- Varun Trivedi
- Department of Biomedical Engineering at Wayne State University, Detroit, MI, USA
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de Guzman RC, Ereifej ES, Broadrick KM, Rogers RA, VandeVord PJ. Alginate-matrigel microencapsulated schwann cells for inducible secretion of glial cell line derived neurotrophic factor. J Microencapsul 2009; 25:487-98. [PMID: 19238724 DOI: 10.1080/02652040802054745] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Controlled expression of glial cell line derived neurotrophic factor (Gdnf) can be integrated in the development of a system for repair of injured peripheral nerves. This delivery strategy was demonstrated via inducible Gdnf from microencapsulated cells in barium alginate. The Schwann cell line RT4-D6P2T was initially modified utilizing an ecdysone-based stable transfection system to produce RT4-Gdnf cells. During construct preparation, it was found that C6 cells (where Gdnf cDNA was isolated) make three Gdnf transcript variants. Additionally, the importance of 5' untranslated region to drive biologically-functional Gdnf synthesis was shown. Encapsulation of RT4-Gdnf in 1% alginate was then performed. It was determined that cells were able to survive at least 1 month in vitro using starting densities of 20, 200 and 2000 cells/capsule and barium ion concentrations of 10, 50, 100 and 200 mM. Most importantly, encapsulated cells secreted exogenous Gdnf upon ponasterone A induction. Mixture of basement membrane extract Matrigel to alginate promoted increased proliferation, cell spreading and Gdnf release. Finally, compression tests showed that cell-loaded microcapsules fractured at 75% diameter compression with 38 kPa of stress. Regulated Gdnf release from these microcapsules in vivo may potentially aid in the regeneration of damaged nerves.
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Affiliation(s)
- Roche C de Guzman
- Department of Biomedical Engineering, Wayne State University, Detroit, MI 48202, USA.
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