Toxicity evaluation of PEDOT/biomolecular composites intended for neural communication electrodes
Toxicity evaluation of PEDOT/biomolecular composites intended for neural communication electrodes
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DOI：
10.1088/1748-6041/4/4/045009
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发表时间：
2009-08-01
影响因子：
4
通讯作者：
von Holst, H.
中科院分区：
文献类型：
--
作者：
Asplund, M.;Thaning, E.;von Holst, H.
涂覆导电聚合物聚(3，4-乙二氧基噻吩基)(PEDOT)的电极具有诱人的电化学性质，可用于神经系统的刺激或记录。在电聚合中加入生物分子作为反离子，可以进一步改善生物材料的性能，消除了在此过程中对表面活性反离子的需要。这种使用肝素或透明质酸的PEDOT/生物分子复合材料以前已经被电化学研究过。在本研究中，评价了它们的生物相容性。采用L929成纤维细胞琼脂糖包被试验、人神经母细胞瘤SH-SY5Y细胞洗脱试验和直接接触试验研究其体外细胞毒性。PEDOT：通过啮齿动物皮质中的聚合物涂层植入物进一步体内评估肝素。没有观察到任何PEDOT材料的细胞毒性反应。对暴露于聚合物涂层植入物的皮质组织的检查显示，无论植入物材料(铂：聚合物或铂)，都有广泛的胶质瘢痕形成。然而，通过测量种植部位到最近神经元的距离和种植周围ED1+细胞密度来量化免疫反应，与铂对照组相当。这些结果表明，PEDOT：肝素表面是无细胞毒性的，在皮质组织中的免疫反应与纯铂对照组没有显著差异。
Electrodes coated with the conducting polymer poly(3,4-ethylene dioxythiophene) (PEDOT) possess attractive electrochemical properties for stimulation or recording in the nervous system. Biomolecules, added as counter ions in electropolymerization, could further improve the biomaterial properties, eliminating the need for surfactant counter ions in the process. Such PEDOT/biomolecular composites, using heparin or hyaluronic acid, have previously been investigated electrochemically. In the present study, their biocompatibility is evaluated. An agarose overlay assay using L929 fibroblasts, and elution and direct contact tests on human neuroblastoma SH-SY5Y cells are applied to investigate cytotoxicity in vitro. PEDOT: heparin was further evaluated in vivo through polymer-coated implants in rodent cortex. No cytotoxic response was seen to any of the PEDOT materials tested. The examination of cortical tissue exposed to polymer-coated implants showed extensive glial scarring irrespective of implant material (Pt:polymer or Pt). However, quantification of immunological response, through distance measurements from implant site to closest neuron and counting of ED1+ cell density around implant, was comparable to those of platinum controls. These results indicate that PEDOT: heparin surfaces were non-cytotoxic and show no marked difference in immunological response in cortical tissue compared to pure platinum controls.