The enhanced bactericidal effect of plasma sprayed zinc-modified calcium silicate coating by the addition of silver

Our previous work demonstrated the antibacterial activity of plasma sprayed zinc-modified calcium silicate coating. To enhance the bactericidal effect, in this paper, silver and zinc co-incorporated calcium silicate coating (ZC0.3-Ag) was fabricated onto Ti–6Al–4V substrate via plasma spraying technology. The coating was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) measurements. Transmission electron microscopy (TEM) showed that the silver nanoparticles 10–100 nm in diameter were randomly distributed in the amorphous matrix after the silver modification. In chemical durability test, the ZC0.3-Ag coating presented improved chemical stability when compared with that of the original and Ag-doped coating. In vitro antibacterial study indicated that the inactivation of bacteria (Staphylococcus aureus and Escherichia coli) on the ZC0.3-Ag coating was significantly enhanced compared to that on the Zn-modified coatings. The enhanced bactericidal activity was attributed to the addition of silver. Cytocompatibility evaluation demonstrated that the ZC0.3-Ag coating surface supported the adhesion and spreading of human mesenchymal stem cells (hMSCs), and no significant cytotoxicity was observed for the coating.