Graphene-Based Hydrogels For Biomedical Applications

Abstract

Graphene-based materials are useful reinforcing agents to modify the mechanical properties of hydrogels. Here, we present an approach to covalently incorporate graphene into hydrogels via radical copolymerization to enhance the dispersion and conjugation of graphene within the hydrogels. Graphene oxide (GO) was chemically modified to present surface-grafted methacrylate groups (MAG). In comparison to GO, higher concentrations of MAG can be stably dispersed in a pre-gel solution containing methacrylated gelatin (GelMA) without aggregation or significant increase in viscosity. In addition, the resulting MAG-GelMA hydrogels demonstrated a significant increase in fracture strength with increasing MAG concentration. Interestingly, the rigidity of the hydrogels was not significantly affected by the covalently incorporated graphene. Therefore, our approach can be used to enhance the structural integrity and resistance to fracture of the hydrogels without inadvertently affecting their rigidity, which is known to affect the behavior of encapsulated cells. The biocompatibility of MAG-GelMA hydrogels was confirmed by measuring the viability and proliferation of the encapsulated fibroblasts. Overall, this study highlights the advantage of covalently incorporating graphene into a hydrogel system, and improves the quality of cell-laden hydrogels.