Preparation and biological assessment of a ZrO2-based bone scaffold coated with hydroxyapatite and bioactive glass composite

ABSTRACT Zirconia (ZrO2) bioceramics has superior stiffness, prominent fracture toughness and fracture strength. However, ZrO2 is almost bioinert material as an alternative scaffolds for repairing bone defects. In this paper, we prepared a porous ZrO2-based bone scaffold coated with hydroxyapatite (HA) and bioactive glass (BG) composite and optimized the quality hybrid proportion of HA and BGs composite coating and sintering temperature. The scaffold has a dense composite coating at the coating sintering temperature of 950°C and HA content of 70% with Ca2SiO4 and β-TCP, HA and Ca10(PO4)6CO3 phases. The ZrO2 composite scaffold with HA-BG coating was capable of forming rich calcium and phosphorus deposits in the simulated body fluids. Its compression strength was superior to that of the porous ZrO2 scaffold. And the scaffold can promote proliferation of cultured mesenchymal stem cells and the adhesion and propagation of osteosarcoma MG-63 cells. The results exhibited that the excellent mechanical properties, biological activities and good cytocompatibility of the scaffold. Therefore, The composite scaffold represents a potential bone implant for future clinical applications.