ARC Centre of Excellence for Electromaterials Science, Intelligent Polymer Research Institute, University of Wollongong, Wollongong, NSW 2522, Australia.
Biomaterials. 2011 Oct;32(30):7309-17. doi: 10.1016/j.biomaterials.2011.06.047. Epub 2011 Jul 13.
Conducting polymers with pendant functionality are advantageous in various bionic and organic bioelectronic applications, as they allow facile incorporation of bio-regulative cues to provide bio-mimicry and conductive environments for cell growth, differentiation and function. In this work, polypyrrole substrates doped with chondroitin sulfate (CS), an extracellular matrix molecule bearing carboxylic acid moieties, were electrochemically synthesized and conjugated with type I collagen. During the coupling process, the conjugated collagen formed a 3-dimensional fibrillar matrix in situ at the conducting polymer interface, as evidenced by atomic force microscopy (AFM) and fluorescence microscopy under aqueous physiological conditions. Cyclic voltammetry (CV) and impedance measurement confirmed no significant reduction in the electroactivity of the fibrillar collagen-modified conducting polymer substrates. Rat pheochromocytoma (nerve) cells showed increased differentiation and neurite outgrowth on the fibrillar collagen, which was further enhanced through electrical stimulation of the underlying conducting polymer substrate. Our study demonstrates that the direct coupling of ECM components such as collagen, followed by their further self-assembly into 3-dimensional matrices, has the potential to improve the neural-electrode interface of implant electrodes by encouraging nerve cell attachment and differentiation.
具有悬垂官能团的导电聚合物在各种仿生和有机生物电子应用中具有优势，因为它们允许轻松掺入生物调节线索，为细胞生长、分化和功能提供生物模拟和导电环境。在这项工作中，用带有羧酸基团的细胞外基质分子硫酸软骨素（CS）掺杂的聚吡咯基底通过电化学合成并与 I 型胶原结合。在偶联过程中，共轭胶原在导电聚合物界面原位形成 3 维纤维状基质，这可以通过原子力显微镜（AFM）和在水生理条件下的荧光显微镜得到证实。循环伏安法（CV）和阻抗测量证实，纤维状胶原修饰的导电聚合物基底的电活性没有显著降低。大鼠嗜铬细胞瘤（神经）细胞在纤维状胶原上表现出分化和神经突生长增加，通过对下面的导电聚合物基底进行电刺激进一步增强。我们的研究表明，ECM 成分（如胶原）的直接偶联，随后进一步自组装成 3 维基质，有可能通过鼓励神经细胞附着和分化来改善植入电极的神经-电极界面。
