Graphene oxide and electroactive reduced graphene oxide-based composite fibrous scaffolds for engineering excitable nerve tissue

This study systematically investigates the role of graphene oxide (GO) and reduced GO/silk-based composite micro/nano- fibrous scaffolds in regulating neuronal cell behavior in vitro, given the limited comparative studies on the effects of graphene family materials on nerve regeneration. Fibrous scaffolds can mimic the architecture of the native extracellular matrix and are potential candidates for tissue engineering peripheral nerves. Silk/GO micro/nano- fibrous scaffolds were electrospun with GO loadings 1% to 10% wt., and optionally post-reduced in situ to explore a family of electrically conductive non-woven silk/rGO scaffolds. Conductivities up to 4×10⁻⁵ S cm⁻¹ were recorded in the dry state, which increased up to 3×10⁻⁴ S cm⁻¹ after hydration. Neuronoma NG108-15 cells adhered and were viable on all substrates. Enhanced metabolic activity and proliferation were observed on the GO-containing scaffolds, and these cell responses were further promoted for electroactive silk/rGO. Neurite extensions up to 100 μm were achieved by day 5, with maximum outgrowth up to ~250 μm on some of the conductive substrates. These electroactive composite fibrous scaffolds exhibit potential to enhance the neuronal cell response and could be versatile supportive substrates for neural tissue engineering applications.