Graphene-reinforced calcium phosphate cements for bone tissue engineering

F decades, natural calcium phosphate cements (CPCs) derived from sintered animal bone have been investigated to treat bone defects. However, they have low mechanical strength as a critical limit. Graphene not only improves the mechanical properties of scaffolds but promotes osteoinduction. To this end, reduced graphene oxide-incorporated natural calcium phosphate cements (RGOCPCs) were fabricated for reinforcement of CPCs’ characteristics. The fabricated RGO-CPCs showed distinct surface properties and chemical properties according to the RGO concentration. The mechanical properties of RGO-CPCs were significantly improved compared to those of CPCs. In in-vitro studies using a mouse osteoblast cell line and rat-derived adipose stem cells, RGO-CPCs were little toxic to the both cells although high concentrations of RGO decreased the cell adhesion rate and cell viability. Western blotting, immunocytochemistry, and the Alizarin red staining assay revealed that osteoinductivity of RGO-CPCs was highly increased with the increase of RGO. We conclude that RGO-CPCs can overcome the flaws of previously developed natural CPCs and be potential candidates as bone cements for clinical application of bone repair and regeneration.