Conducting polymers on hydrogel-coated neural electrode provide sensitive neural recordings in auditory cortex
Conducting polymers on hydrogel-coated neural electrode provide sensitive neural recordings in auditory cortex
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DOI：
10.1016/j.actbio.2009.07.034
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发表时间：
2010-01-01
影响因子：
9.7
通讯作者：
Martin, David C.
中科院分区：
文献类型：
--
作者：
Kim, Dong-Hwan;Wiler, James A.;Martin, David C.
最近，大量的努力已经致力于了解影响生物电子传感器功能的因素，并开发用于修饰生物传感器表面的新型涂层技术。由于其众所周知的生物相容性，海藻酸盐水凝胶（HG）已被用作神经电极的涂层材料，以促进细胞的紧密整合，为局部药物递送提供支架，并在硬电极和中枢神经系统的软组织之间建立机械缓冲。然而，在动物模型中使用hg包覆电极记录神经信号的评估仍然很差。在此，我们使用不同厚度的HG涂层沉积在微制造电极上，植入豚鼠听觉皮层，研究电极周围源神经元邻近程度的影响。我们还评估了导电聚合物聚（3,4-乙烯二氧噻吩）（PEDOT）在改善hg包覆神经电极记录功能方面的作用。通过清晰检测单元的数量（80 μ m厚涂层为30%）和平均信噪比（80 μ m厚涂层为3.91）可以看出，较厚的HG涂层明显降低了记录功能。然而，在电极上沉积导电聚合物PEDOT可以恢复HG涂层（30 μ m）造成的电极功能损失。这些导电聚合物/HG涂层不仅可以改善电极的生物相容性，还可以促进更有效的信号传输，从而有可能改善神经电极的长期性能。(C) 2009材料学报Elsevier Ltd.出版。版权所有。
Recently, a significant amount of effort has been dedicated to understanding factors that influence the functionality of bio-electronic sensors and to development of novel coating technologies for modifying biosensor surfaces. Due to its well-known biocompatibility, alginate hydrogel (HG) has been used as a coating material on neural electrodes for promoting intimate cellular integration, providing a scaffold for local drug delivery, and creating a mechanical buffer between hard electrodes and the soft tissues of the central nervous system. However, neural signal recordings using HG-coated electrodes in animal models are still poorly evaluated. Here, we investigated the effect of the proximity of source neurons around the electrode sites using HG coatings with various thicknesses deposited on microfabricated electrodes, implanted in auditory cortex of guinea pigs. We also evaluated the role of the conducting polymer poly(3,4-ethylenedioxythiophene) (PEDOT) in improving the recording functionality of the HG-coated neural electrodes. A significant loss in recording functionality was observed with thicker HG coatings, as determined by the number of clearly detectable units (30% with 80 mu m thick coatings) and average signal-to-noise ratios (3.91 with 80 mu m thick coatings). However, deposition of the conducting polymer PEDOT on the electrode sites restored the lost functionality of the electrodes caused by the HG coatings (30 mu m). These conducting polymer/HG coatings have the potential to improve long-term performance of the neural electrodes not only by improving the electrode biocompatibility but also by facilitating more efficient signal transmission. (C) 2009 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.