Fabrication of HA-SrCO₃-SiO₂ composite coatings and their bioactivity

In order to fabricate the hydroxyapatite(HA) composite coating which is more excellent in aspects of mechanical properties and bioactivity, HA-SrCO₃-SiO₂ composite coatings were fabricated firstly using electrophoretic deposition method aided with high temperature sintering by adding binary osteogenesis trace element compounds SrCO₃ and SiO₂, and using chitosan as porogen. Then, the composite coatings were tested and characterized by FTIR, XRD, SEM, EDS, universal material testing machine and electrochemical workstation, and the bioactivity of HA-SrCO₃-SiO₂ composite coatings was evaluated by immersion and cultivation in simulated body fluid of 1.5 times ionic concentration. The results show that the bonding strength between HA-SrCO₃-SiO₂ composite coating and substrate reaches 28.6 MPa. After immersion and cultivation in simulated body fluid for 7 d, the surface of composite coating is completely covered by carbonated hydroxyapatite, which indicates that the composite coating possesses better bioactivity than those of single osteogenesis trace element compound doped composite coating and pure HA coating. The conclusions obtained show that the prepared HA-SrCO₃-SiO₂ composite coatings would be developed as a brand generation of the artificial bone replacement material.