Bioactive conducting polymers for neural interfaces application to vision prosthesis

Bioactive conducting polymers (CPs) have the potential to provide superior neural interfaces to conventional metal electrodes by lowering interfacial impedance, reducing strain-mismatch and controlling the interaction of surrounding tissue. Application to vision prosthesis is demonstrated in this study where cell adherence and neurite outgrowth were stimulated via biomolecules entrapped within the CP matrix. The responses of two different cell types to biologically modified poly(ethylene dioxythiophene) (PEDOT) were studied by incorporating the appropriate differentiation factors for each cell type. For the PC12 cell line, nerve growth factor (NGF) was incorporated and for the clonal retinal ganglion cell (RGC-5), staurosporine (SS) was used. Platinum (Pt) electrodes coated with bioactive PEDOT promoted superior cell responses when compared to the bare Pt electrodes for both cell types. It was also demonstrated that cells preferentially adhered to the PEDOT surface, indicating that these CPs have surface topography more suited to cell attachment than conventional smooth metal surfaces.