Sol-gel preparation of Zn-doped fluoridated hydroxyapatite films

In comparison with hydroxyapatite (HA), fluoridated hydroxyapatite (FHA) films on metallic prostheses demonstrate better long-term effectiveness since FHA is less soluble and possesses similar bioactivity. Zn is well established as an essential trace element known to have positive effect on osteoblastic cell proliferation and bone formation. It is expected that the incorporation of Zn into FHA films could create better physiochemical performance. In this work, FHA films with different Zn content on Ti6Al4V were prepared by sol-gel dip-coating method, Ca(NO3)2, Zn(NO3)2, P2O5 and HPF6 were used as the precursors, and the F/Ca molar ratio was 1/15. The crystalline phase and the surface morphology of the Zn-doped FHA films were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively, and the Zn content in the surface was determined by X-ray photoelectron spectroscopy (XPS) analysis. The results showed that the concentrations of Zn in the surface were 10 to 30 times higher than the designed value. The Zn-doped FHA films were soaked into simulated body fluid (SBF) solutions for bioactivity evaluation, and the morphology on the surface of the soaked films was examined using SEM, the result showed that the Zn-doped FHA films had similar bioactivity as the FHA film.