Bioactivity of plasma sprayed wollastonite coatings in simulated body fluid

Wollastonite coatings were deposited by plasma spraying and incubated in simulated body fluids to investigate the nucleation and growth of apatite on their surface. Surface structural of the coatings were analyzed by XRD and IR technologies. SEM and EDS were used to observe surface and cross-section morphologies and determine the composition of wollastonite coatings before and after immersion in simulated body fluid. The changes in the concentrations of calcium, silicon and phosphorus in the simulated body fluids due to the immersion of the coatings were measured by inductively coupled plasma atomic emission spectroscopy. The cytocompatibility of wollastonite coatings was examined by osteoblasts culturing test. The carbonate-containing hydroxyapatite (CHA) layer was formed on the surface of plasma sprayed wollastonite coating soaked in SBF solution. Prior to the formation of the CHA layer, silica-rich layer appeared on the surface of plasma sprayed wollastonite coating soaked in SBF solution. The formation of CHA layer on coating surface indicates wollastonite coating had a good bioactivity. Osteoblasts survive and proliferate on the surface of wollastonite coating, which showed plasma sprayed wollastonite coatings possess good cytocompatibility.