Enhanced apatite-forming ability and cytocompatibility of porous and nanostructured TiO2/CaSiO3 coating on titanium

Abstract

To improve the bioactivity and cytocompatibility of biomedical titanium dioxide coating, many efforts have been made to modify its surface composition and topography. Meanwhile, CaSiO3 was commonly investigated as coating material on titanium implants for fast fixation and firm implant-bone attachment due to its demonstrated bioactivity and osteointegration. In this work, gradient TiO2/CaSiO3 coating on titanium was prepared by a two-step procedure, in which porous and nanostructured TiO2 coating on titanium was prepared by plasma electrolytic oxidation in advance, and then needle and flake-like CaSiO3 nanocrystals were deposited on the TiO2 coating surface by electron beam evaporation. In view of the potential clinical applications, apatite-forming ability of the TiO2/CaSiO3 coating was evaluated by simulated body fluid (SBF) immersion tests, and MG63 cells were cultured on the surface of the coating to investigate its cytocompatibility. The results show that deposition of CaSiO3 significantly enhanced the apatite-forming ability of nanostructured TiO2 coating in SBF. Meanwhile, the MG63 cells on TiO2/CaSiO3 coating show higher proliferation rate and vitality than that on TiO2 coating. In conclusion, the porous and nanostructured TiO2/CaSiO3 coating on titanium substrate with good apatite-forming ability and cytocompatibility is a potential candidate for bone tissue engineering and implant coating.