Corrosion performance and biological properties of electrophoretically deposited bioactive glass-zirconia core-shell composite coating on Ti6Al4V substrate

For the simultaneous improvement of the biological and corrosion performance of the Ti6Al4V substrate, a bioactive glass-zirconia core-shell composite coating is thoroughly studied. For this purpose, the bioactive glass and core-shell particles were prepared using a combination of sol-gel and sonochemical processing techniques and then electrophoretically deposited on anodized substrate. The appropriate cohesion due to the core-shell particles, lower coating thickness, and the reduced cathodic voltage resulted in higher barrier performance of the coatings compared to the bioactive glass coating group as tested in a phosphate-buffered saline solution (impedance (|Z|) was 7.6 times higher). In addition, despite the presence of a ZrO₂ shell around the bioactive glass particles, the bioactivity was not greatly affected. Furthermore, cell viability study on the core-shell coating, following exposure to MG63 cells, confirmed the non-cytotoxic nature of the coatings. According to the SEM images, cell proliferation improved significantly on the core-shell coatings compared to a bioactive glass group, perhaps due to the excellent pH control owing to the presence of a zirconia shell. These results confirmed the positive effects of using core-shell coating on the improvement of bioactivity and corrosion performance of the Ti6Al4V implant.