The biological and electrical trade-offs related to the thickness of conducting polymers for neural applications
The biological and electrical trade-offs related to the thickness of conducting polymers for neural applications
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DOI：
10.1016/j.actbio.2014.04.004
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发表时间：
2014-07-01
影响因子：
9.7
通讯作者：
Poole-Warren, Laura A.
中科院分区：
文献类型：
--
作者：
Baek, Sungchul;Green, Rylie A.;Poole-Warren, Laura A.
聚（3,4-乙烯二氧噻吩）（PEDOT）薄膜由于其优异的化学稳定性和电学性能而引起了人们对铂神经假体电极涂层的极大兴趣。本研究系统地研究了由不同数量的电荷和掺杂离子形成的PEDOT涂层，并研究了最适合神经细胞相互作用的表面特性组合。通过改变电沉积电荷从0.05到1C cm（-2）来制备PEDOT样品。样品分别掺杂聚苯乙烯磺酸盐、甲酰磺酸盐或高氯酸盐。扫描电子显微图显示，随着用于制造样品的电荷的增加，厚度和结核度都增加，并且较大的掺杂剂在所有厚度上都产生更光滑的薄膜。x射线光电子能谱证实了样品中电荷的数量与掺杂剂的厚度和数量直接对应。此外，随着厚度和球化程度的增加，所有PEDOT涂层的电化学性能都得到了改善。然而，神经细胞粘附和生长分析显示，存在与厚度和结节性相关的直接生物权衡。在较厚、较粗糙的样品上，细胞附着、生长和分化较差，但较薄、较少结节的PEDOT薄膜比裸铂有显著改善。制备的PEDOT/pTS电荷密度为
Poly(3,4-ethylenedioxythiophene) (PEDOT) films have attracted substantial interest as coatings for platinum neuroprosthetic electrodes due to their excellent chemical stability and electrical properties. This study systematically examined PEDOT coatings formed with different amounts of charge and dopant ions, and investigated the combination of surface characteristics that were optimal for neural cell interactions. PEDOT samples were fabricated by varying the electrodeposition charge from 0.05 to 1C cm(-2). Samples were doped with either poly(styrenesulfonate), tosylate (pTS) or perchlorate. Scanning electron micrographs revealed that both thickness and nodularity increased as the charge used to produce the sample was increased, and larger dopants produced smoother films across all thicknesses. X-ray photoelectron spectroscopy confirmed that the amount of charge directly corresponded to the thickness and amount of dopant in the samples. Additionally, with increased thickness and nodularity, the electrochemical properties of all PEDOT coatings improved. However, neural cell adhesion and outgrowth assays revealed that there is a direct biological tradeoff related to the thickness and nodularity. Cell attachment, growth and differentiation was poorer on the thicker, rougher samples, but thin, less nodular PEDOT films exhibited significant improvements over bare platinum. PEDOT/pTS fabricated with a charge density of