Evaluation of a conducting elastomeric composite material for intramuscular electrode application
| Autor: | X. Tracy Cui, Azante Y. Griffith, Lee E. Fisher, Michael J. Looker, Brady J. Clapsaddle, X. Sally Zheng, Emily Chang |
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| Rok vydání: | 2020 |
| Předmět: |
Male
Muscle tissue Materials science 0206 medical engineering Composite number Biomedical Engineering Biocompatible Materials 02 engineering and technology Carbon nanotube Elastomer Biochemistry Article law.invention Rats Sprague-Dawley Biomaterials chemistry.chemical_compound Silicone law Electrochemistry medicine Animals Receptors Cholinergic Composite material Molecular Biology Conductive polymer Muscles X-Ray Microtomography General Medicine 021001 nanoscience & nanotechnology Magnetic Resonance Imaging 020601 biomedical engineering Electrodes Implanted medicine.anatomical_structure Elastomers chemistry Electrode Implant 0210 nano-technology Biotechnology |
| Zdroj: | Acta Biomater |
| ISSN: | 1742-7061 |
| DOI: | 10.1016/j.actbio.2019.12.021 |
| Popis: | Electrical stimulation of the muscle has been proven efficacious in preventing atrophy and/or reanimating paralyzed muscles. Intramuscular electrodes made from metals have significantly higher Young's Moduli than the muscle tissues, which has the potential to cause chronic inflammation and decrease device performance. Here, we present an intramuscular electrode made from an elastomeric conducting polymer composite consisting of PEDOT-PEG copolymer, silicone and carbon nanotubes (CNT) with fluorosilicone insulation. The electrode wire has a Young's modulus of 804 (±99) kPa, which better mimics the muscle tissue modulus than conventional stainless steel (SS) electrodes. Additionally, the non-metallic composition enables metal-artifact free CT and MR imaging. These soft wire (SW) electrodes present comparable electrical impedance to SS electrodes of similar geometric surface area, activate muscle at a lower threshold, and maintain stable electrical properties in vivo up to 4 weeks. Histologically, the SW electrodes elicited significantly less fibrotic encapsulation and less IBA-1 positive macrophage accumulation than the SS electrodes at one and three months. Further phenotyping the macrophages with the iNOS (pro-inflammatory) and ARG-1 (pro-healing) markers revealed significantly less presence of pro-inflammatory macrophage around SW implants at one month. By three months, there was a significant increase in pro-healing macrophages (ARG-1) around the SW implants but not around the SS implants. Furthermore, a larger number of AchR clusters closer to SW implants were found at both time points compared to SS implants. These results suggest that a softer implant encourages a more intimate and healthier electrode-tissue interface. Statement of significance Intramuscular electrodes made from metals have significantly higher Young's Moduli than the muscle tissues, which has the potential to cause chronic inflammation and decrease device performance. Here, we present an intramuscular electrode made from an elastomeric conducting polymer composite consisting of PEDOT-PEG copolymer, silicone and carbon nanotubes with fluorosilicone insulation. This elastomeric composite results in an electrode wire with a Young's modulus mimicking that of the muscle tissue, which elicits significantly less foreign body response compared to stainless steel wires. The lack of metal in this composite also enables metal-artifact free MRI and CT imaging. |
| Databáze: | OpenAIRE |
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