In vitro cytocompatibility of plasma-sprayed dicalcium silicate/zirconia composite coatings

Dicalcium silicate/zirconia composite coatings composed of 70 wt% zirconia and 30 wt% dicalcium silicate were prepared by plasma spraying. Human osteoblasts were used for evaluation of the cytocompatibility of the composite coatings with Ti and hydroxyapatite (HA) coatings used as controls. The cells on the composite coatings possessed abundant extensions, and the cell number was also the highest among these coatings. During the 7 days culture, cell density on the composite coatings maintained higher than that on the Ti coatings, but similar to that on the HA coatings. To evaluate the bioactivity, the composite coatings were immersed in simulated body fluids and cell culture media. Ca–P minerals were deposited on the coating surface after immersion in the cell culture media for 1 day, while only scattered particles were found after soaking in simulated body fluids for 2 days. The enhanced Ca–P mineral formation rate of the composite coatings was explained by the Si–OH functional groups and the adsorbed proteins on the coating surface.