Biocompatible graphene oxide-collagen composite aerogel for enhanced stiffness and in situ bone regeneration.

The developing bone graft substitutes have become a promising strategy for repairing large bone loss. Aerogels that made from natural polymers were widely investigated for synthetic bone graft due to their high porosity and great biocompatibility. However, the mechanical properties of natural polymer aerogel are extremely poor for large bone repair. Graphene oxide (GO) is one of the nanomaterials with great mechanical properties as well as biocompatibility, making it a promising component when constructing hybrid aerogels for bone regeneration. In the present study, we have developed a highly porous aerogel consist of GO and type I collagen (COL) using sol-gel process (concentrations of GO: 0%, 0.05%, 0.1%, and 0.2% w/v). Results indicated that GO-COL aerogels were highly porous and hydrophilic. Furthermore, the compressive modulus of GO-COL aerogels was enhanced with the GO concentration increased. For in vitro experiment, 0.1% GO-COL aerogel exhibited better biomineralization rate and cell compatibility than other groups of aerogels. For in vivo study, a better bone repair effect was observed in 0.1% GO-COL aerogels than COL aerogel in rat cranial defect models. This study indicated that 0.1% GO-COL aerogel exhibited good biocompatibility and osteogenic ability in vivo, which make it a promising biocompatible scaffold for bone regeneration and tissue engineering.