Graphene oxide reinforced hydrogels for osteogenic differentiation of human adipose-derived stem cellsElectronic supplementary information (ESI) available. See DOI: 10.1039/c7ra02410j

Polyethylene glycol (PEG)-based hydrogels are attractive biomaterials for stem cell culture due to their tunable material properties and mechanical strength. However, the lack of cell adhesion sites has been one of the major obstacles in generating functional tissue constructs using PEG-based hydrogels. To overcome this limitation, we designed graphene oxide (GO)-functionalized polyethylene glycol diacrylate (PEGDA) hydrogels to assign cell adhesion-dependent biofunctionality. The incorporation of GO into three-dimensional PEGDA networks improved cell attachment, engaged focal adhesion, and activated focal adhesion kinase (FAK) signaling of hydrogel-encapsulated human adipose-derived stem cells (hADSCs). Compared to the control PEGDA hydrogel, GO functionalized PEGDA hydrogel (PEGDA-GO) resulted in enhanced cell viability and survival. When subsequently cultured under osteoinductive condition, PEGDA-GO enhanced osteogenic differentiation and stimulated osteogenic phenotypes compared to those in its PEGDA counterpart. Taken together, GO could serve as an effective biofunctionalizing moiety to modulate stem cell adhesion and differentiation. In this study, we designed graphene oxide-functionalized polyethylene glycol diacrylate hydrogels to assign cell adhesion-dependent biofunctionality, which resulted in cell adhesion dependent osteogenic differentiation of encapsulated stem cells.