Graphene-Polymer Nanocomposite Materials for Biomedical Applications

Abstract

Polymer-based materials, such as fibers, hydrogels, and elastomers, are widely used in biomedical applications for their compatibility with living organisms. However, due to their limited range of physical and chemical properties, it becomes necessary to augment their functions by appropriate modifications. Incorporating nanostructures having unique and favorable properties into a polymer-based material would be a highly strategy for this purpose. In this work, we developed a nanocomposite hydrogel system by covalently incorporating graphene oxide (GO) into gelatin-based hydrogels. GO is a 2D carbon nanomaterial well known for its electronic properties and mechanical strength. Mechanical strength of the resulting nanocomposite hydrogel was significantly enhanced as compared to gelatin-only hydrogel which showed low mechanical stability. In addition, covalent incorporation proved to be a much more effective method than physical incorporation. This was due to the fact that GO was highly susceptible to aggregation by π-π stacking and depletion forces especially and was not stably dispersed especially in high polymer concentrations. By modifying the surface of GO with methacrylic groups, GO was able to undergo copolymerization with gel-forming polymer chains, resulting in covalent incorporation of GO into the hydrogel. In addition, 3D in vitro cell culture study demonstrated the biocompatibility of GO-linked hydrogel, which atest to their potential applications in biomedical engineering.