Electrophoretic deposition and characterization of bioglass-whisker hydroxyapatite nanocomposite coatings on titanium substrate

Electrophoretic deposition of bioactive glass (BG) coatings reinforced by whisker hydroxyapatite (WHA) particles was investigated in this work. Different BG powders as freeze dried (FBG) with fine particle size and calcined (CBG) with coarse particle size were used. Hydroxyapatite with whisker morphology reinforced microstructure of BG composite coatings and improved their mechanical properties. CBG and FBG coatings with 50 and 75 wt% WHA respectively, showed the highest bonding strength and bioactivity response as optimum coatings. Combination of WHA and BG particles had synergistic effect on the generation of apatite layer on the coatings during bioactivity test. Cellular behavior was influenced by surface roughness and environment alkalinization generated by BG dissolution. Finer particle size of FBG compared to CBG had positive effect on bioactivity and antibacterial characteristics of the coatings due to its rapid dissolution. FBG powder calcination conducted simultaneously with sintering of corresponding coated samples without negative effect on BG characteristics.