Department of Mechanical and Manufacturing Engineering, Trinity College Dublin, The University of Dublin, Dublin, Ireland.
J Mater Chem B. 2019 Aug 7;7(31):4811-4820. doi: 10.1039/c9tb01028a.
The rapidly expanding fields of bioelectronics, and biological interfaces with electronic sensors and stimulators, are placing an increasing demand on candidate materials to serve as robust surfaces that are both biocompatible, stable and electroconductive. Amongst conductive polymers, poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) is a promising material in biomedical research due to its appropriate stability and high conductivity, however its intrinsic solubility requires a crosslinking process that can limit its conductivity and biocompatibility. Poly(ethylene glycol) is known to be a suitably anti-immunogenic moiety and its derivatives have been widely used for biomedical applications. In this study we investigate the application of poly(ethylene glycol)diglycidyl ether (PEGDE) as an effective crosslinker and conductive filler for PEDOT:PSS. From our interpretation of XPS analysis we hypothesise that the crosslinking reaction is occurring via the epoxy ring of PEGDE interacting with the sulfonic groups of excel PSS chains, which reaches a saturation at 3 w/v% PEGDE concentration. PEGDE crosslinked films did not disperse in aqueous environments, had enhanced electrical conductivity and imparted a significant degree of hydrophilicity to PEDOT:PSS films. This hydrophilicity and the presence of biocompatible PEGDE led to good cell viability and a significantly increased degree of cell spreading on PEDOT:PSS films. In comparison to widely reported chemical crosslinking via glycidoxy propyltrimethoxysilane (GOPS), this original crosslinking yields a highly hydrophilic 2D film substrate with increased electroconductive and biocompatibility properties, resulting in a next-generation formulation for bioengineering applications.
生物电子学和生物与电子传感器和刺激器的界面这两个快速发展的领域，对候选材料提出了越来越高的要求，这些材料需要具备稳定、生物相容和导电的特性，以作为坚固的表面。在导电聚合物中，聚(3,4-亚乙基二氧噻吩):聚(苯乙烯磺酸盐)(PEDOT:PSS)由于其稳定性和导电性高，在生物医学研究中是一种很有前途的材料，然而，其内在的可溶性需要交联过程，这可能会限制其导电性和生物相容性。聚乙二醇(PEG)是一种合适的抗免疫原性部分，其衍生物已广泛应用于生物医学应用。在本研究中，我们研究了聚乙二醇二缩水甘油醚(PEGDE)作为 PEDOT:PSS 的有效交联剂和导电填料的应用。通过对 XPS 分析的解释，我们假设交联反应是通过 PEGDE 的环氧环与 excel PSS 链的磺酸基团相互作用而发生的，当 PEGDE 浓度达到 3 w/v%时达到饱和。PEGDE 交联膜在水相环境中不分散，具有增强的导电性，并赋予 PEDOT:PSS 膜显著的亲水性。这种亲水性和生物相容性 PEGDE 的存在导致 PEDOT:PSS 膜具有良好的细胞活力和显著增加的细胞铺展程度。与广泛报道的通过缩水甘油丙基三甲氧基硅烷(GOPS)进行的化学交联相比，这种原始交联产生了具有高亲水性的 2D 薄膜基底，具有增强的导电性和生物相容性，为生物工程应用提供了下一代配方。
