Microstructure, mechanical properties and in vitro biocompatibilities of a novel bionic hydroxyapatite bone scaffold prepared by the addition of boron nitride

Hydroxyapatite (HA) is an ideal bone insert material due to its biocompatibility and osteoconductivity, but the poor mechanical properties limit its wide application in clinical practice. The aim of this work is to fabricate a novel composite that with similar porous structure to cortical bone and high mechanical properties by the addition of boron nitride (BN) and sintered in air at 1250 °C for 40 min. In mechanical properties, the maximum flexural strength, elastic modulus and fracture toughness are 94.04 MPa, 69.46 GPa and 1.16 MPa m^1/2, respectively, which are improved by 20.56%, 12.87% and 8.41%, respectively. In the microscopy of surface and fracture surface, the porous structure similar to cortical bone is observed. There are microscale and nanoscale pores, and the pores present an interconnected structure. In vitro biocompatibility assessment, the addition of BN and its reaction product have no adverse effect on osteoblast viability, which even promotes osteogenic differentiation and mineralization.