Mg/Ag ratios induced in vitro cell adhesion and preliminary antibacterial properties of TiN on medical Ti-6Al-4V alloy by Mg and Ag implantation

Titanium alloy (Ti-6Al-4V) has been extensively applied in joint replacements, orthopedic prostheses, dental implants, and so on, because of their good biocompatibilities and mechanical properties. However, the inferior antibacterial activity and biological inert of titanium alloy limit its application in the field of hard tissue repair. Therefore, the surface modification to Ti-6Al-4V is well method. In this paper, titanium nitride (TiN) was first deposited on the surface of Ti-6Al-4V alloy. Then magnesium (Mg) and silver (Ag) ions with different ratios (Mg:Ag = 0.5:1; 1:1; 3:1) were implanted into TiN via a plasma immersion ion implantation (PIII) system to explore the effects of Mg/Ag ratios on the cell adhesion and the preliminary antibacterial properties. Structure characteristics and compositions of Mg/Ag implanted TiN were analyzed by scanning electron microscope (SEM) and X-ray diffraction (XRD). X-ray photoelectron spectrometer (XPS) proved the presence of Mg and Ag on the surface of Mg/Ag-TiN. The results of water contact angle and protein adsorption proved that the wettability and protein adsorption energy of the materials increased significantly with the increase of Mg content. Moreover, in vitro investigations indicated that Mg/Ag (1/1)-TiN exhibited the best cell adhesion and spreading activity, and ideal proliferation, as well as preliminary antibacterial activities, which made it has a good application prospect in orthopedic material.