Biological actions of Cu/Zn coimplanted TiN on Ti-6Al-4V alloy

Ti-6Al-4V alloy, as a widely used orthopedic and dental implant, has excellent biocompatibility and machinability. However, its poor corrosion resistance and antibacterial property may lead to tissue inflammation and postoperative infection, which hinders its further development. In this paper, to solve the above problems, copper (Cu) and zinc (Zn) ions were coimplanted into a titanium nitride (TiN) coated Ti-6Al-4V alloy via a plasma immersion ion implantation system (PIII). Then, the structure and composition of Cu/Zn coimplanted TiN (Cu/Zn-TiN-PIII) were characterized by scanning electron microscopy and x-ray photoelectron spectroscopy. Also, the results of the corrosion test, the water contact angles test, and the protein electrophoresis experiment showed that the corrosion resistance, hydrophilicity, and the protein adsorption capacity of Cu/Zn-TiN-PIII were improved simultaneously. In addition, compared with TiN-PIII, Cu/Zn-TiN-PIII promoted both cytocompatibility and the antibacterial property according to L929 cells and Escherichia coli assays in vitro. Therefore, Cu/Zn-TiN-PIII may be a good candidate for orthopedic implants.