Excellent Osteoinductivity of Biphasic Calcium Phosphate Bioceramics with the Optimal Design of Pore Size Distribution and Micro-Nano Topography

Further enhance the bioactivity and osteoinductivity of biphasic calcium phosphate (BCP) bioceramics to meet the requirements of regenerative medicine is still a hot topic. Due to the uncontrolled pore structure and large grain size, the osteoinductivity of the conventional BCP bioceramics is restricted to a large extent. Herein, this study introduced a novel pore foaming method to fabricate BCP bioceramics with appropriately ordered macropores and abundant micropores by combing the advantages of the microsphere-sintering method with the H₂O₂ gas foaming method. Moreover, different sintering methods were adopted to adjust the micro-nano topography of BCP bioceramics. Due to the optimal design of pore size distribution and nano topography, the obtained BCP bioceramics could well trigger and regulate in vitro biological responses, such as degradation, bone-like apatite formation, protein adsorption, cell behaviors, angiogenic and osteogenic differentiation. In vivo canine intramuscular implantation further confirmed that the nanotopography and appropriately ordered pore structure might be responsible for the excellent neovascularization and osteoinductivity of the obtained BCP bioceramics. Collectedly, the osteoinductivity of BCP bioceramics was further enhanced by optimally designing pore structure and micro-nano topography, which hold huge potential to be a potential alternative to the gold standard of autogenous bone in bone repairing applications.