Antibacterial properties and cytocompatibility of Ti-20Zr-10Nb-4Ta alloy surface with Ag microparticles by laser treatment

Abstract

In order to improve the antibacterial behavior of Ti-20Zr-10Nb-4Ta (TZNT) alloy, Ag, with broad-spectrum antibacterial properties, was introduced on the surface of TZNT using a simple and efficient laser surface modification method. After laser treatment of TZNT alloy covered by Ag foil, Ag microparticles were successfully formed on the surface. The SEM, EDS, 3D topography and XRD were investigated to prove the presence of Ag microparticles. The characteristic peaks of cubic silver crystal were observed in XRD results. The Ag2O film on the surface of Ag microparticles was confirmed by XPS. The contact angel tests show that laser60 and laser70 TZNT alloys possess better hydrophilic character and higher free surface energy, compared with untreated TZNT. All laser-treated TZNT alloys reveal a higher OCP, Ecorr and Rct than untreated TZNT. However, a larger corrosion rate and a lower Rf are concluded for laser-treated TZNT alloys due to the influence of Ag microparticles. The results of in vitro antibacterial and cytocompatibility experiments indicate that Ag microparticles exhibit high antibacterial property (with a 96.3% minimum antibacterial rate) against both E. coli and S. aureus and good cytocompatibility with MC3T3-E1. This research presents a simple and efficient laser surface modification method for improving antibacterial resistance of titanium implant surface, which has a good application prospect in orthopaedic field.