Osteoinductive ceramics as a synthetic alternative to autologous bone grafting

TLDR

Biomaterials can be tuned in elasticity and surface texture to become biologically instructive, yet translating porous calcium phosphate ceramics from in vitro proof of concept to clinical use is limited because they typically fail to induce stem cell differentiation required for large bone defect repair. The study fabricated calcium phosphate ceramics with diverse physicochemical and structural properties. Microporosity of the ceramics promoted stem cell osteogenic differentiation and bone formation, and in a sheep large bone defect model the osteoinductive ceramics matched the repair efficacy of autologous bone grafts, demonstrating clinical potential for smart biomaterials.

Abstract

Biomaterials can be endowed with biologically instructive properties by changing basic parameters such as elasticity and surface texture. However, translation from in vitro proof of concept to clinical application is largely missing. Porous calcium phosphate ceramics are used to treat small bone defects but in general do not induce stem cell differentiation, which is essential for regenerating large bone defects. Here, we prepared calcium phosphate ceramics with varying physicochemical and structural characteristics. Microporosity correlated to their propensity to stimulate osteogenic differentiation of stem cells in vitro and bone induction in vivo. Implantation in a large bone defect in sheep unequivocally demonstrated that osteoinductive ceramics are equally efficient in bone repair as autologous bone grafts. Our results provide proof of concept for the clinical application of "smart" biomaterials.