Differential neural cell adhesion and neurite outgrowth on carbon nanotube and graphene reinforced polymeric scaffolds

Abstract

Carbon nanomaterials, such as graphene nanoplatelets (GNPs) and multiwalled carbon nanotubes (MWCNTs) are potential candidates in a large number of biomedical applications. The present study investigates the effect of the difference in morphology of these materials on neural cell regeneration on a biodegradable scaffold. Electrical conductivities of all the hybrid scaffolds are found to be in between that of MWCNT/chitosan scaffold (highest-conductivity) and GNP/chitosan scaffold (lowest-conductivity). While, hybrid scaffolds show improvement in elastic modulus and ultimate tensile strength over MWCNT/chitosan and GNP/chitosan scaffolds. The protein adsorption isotherms of bovine serum albumin (BSA) show greater equilibrium constant (Keq) on GNP/chitosan composites as compared to MWCNT/chitosan composites, proving more potential for cell adhesion in the former. Interactions of HT-22 hippocampal neurons with MWCNT/chitosan, GNP/chitosan and various MWCNT/GNP hybrid chitosan matrices prove cytocompatibility. The neurons acquire elongated geometry on the MWCNT/chitosan scaffold, while GNP reinforcement drives the neurons to spread cellular processes radially.

Keywords: Electrical conductivity; Graphene nanoplatelet; Mechanical property; Multiwalled carbon nanotube; Neural scaffold; Shape dependency.