Microstructural, mechanical and biological properties of hydroxyapatite - CaZrO3 biocomposites

The biofunctionalization of metal implants with bioactive ceramics arises as an appealing strategy for promoting their osseointegration, without impairing implants’ good mechanical resistance. In this work, biocomposites of hydroxyapatite - CaZrO3 were obtained by rate controlled sintering and their microstructure, mechanical properties, biological as well as the effect of stoichiometric calcium zirconate dopant on the decomposition of HA were analysed. The results obtained showed that the addition of CaZrO3 stabilizes the hydroxyapatite at least up to 1300 °C and inhibits the appearance of the α- and β-TCP phases. Moreover, the mechanical properties of the hydroxyapatite were improved with 10 wt% of CaZrO3, despite the increase of porosity. The in vitro assays demonstrated that the biocomposites were biocompatible, since they favoured human osteoblast cells adhesion and proliferation. All the data obtained emphasize the potential of these biocomposites for the aimed biomedical application.