[Biological properties and formation of electrodeposited HA-Ti/HA composite coatings]

In order to improve the bonding strength of the hydroxyapatite (HA) coatings on the metal substrate, we prepared the HA-Ti/HA composite coatings by two-step electrodeposited method, and then we studied the component, microstructure, surface morphologies and the bonding strength of the HA-Ti/HA composite coatings. SBF test and cell culture in vitro were carried out to evaluate the biological properties of the composite coatings. The results showed that the bonding strength of the HA-Ti/HA composite coating (Ti, 51.2wt%) was as high as 21.2 MPa which was 3 times that of pure HA coatings. The coatings' surface was covered by carbonate-apatite layer after being immersed in SBF, and the bone marrow cells attached firmly and proliferated well on the surface of composite coatings. These findings indicate that the composite coatings possess good bioactivity and excellent biocompatibility.