title: Conducting polymers with immobilised fibrillar collagen for enhanced neural interfacing.
abstract: 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.
authors: ARC Centre of Excellence for Electromaterials Science, Intelligent Polymer Research Institute, University of Wollongong, Wollongong, NSW 2522, Australia.
authors: Xiao
authors: X
authors: Liu
authors: Zhilian
authors: Z
authors: Yue
authors: Michael J
authors: MJ
authors: Higgins
authors: Gordon G
authors: GG
authors: Wallace
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry* / Q000378:metabolism; D002454:Cell Differentiation; D002470:Cell Survival; D002809:Chondroitin Sulfates / Q000737:chemistry* / Q000378:metabolism; D004553:Electric Conductivity; D017097:Electric Impedance; D055664:Electrochemical Techniques; D024022:Fibrillar Collagens / Q000737:chemistry* / Q000378:metabolism; D009474:Neurons / Q000166:cytology*; D016716:PC12 Cells; D011108:Polymers / Q000737:chemistry* / Q000378:metabolism; D011758:Pyrroles / Q000737:chemistry* / Q000378:metabolism; D051381:Rats
chemical_list: D001672:Biocompatible Materials; D024022:Fibrillar Collagens; D011108:Polymers; D011758:Pyrroles; C067635:polypyrrole; D002809:Chondroitin Sulfates