27 / 2021-06-27 16:37:33

Enhancement of biological properties and antimicrobial effects of TiN coatings on titanium alloys with Ag/Ta in different proportions using Ag+ and Ta+ co-implanted

plasma immersion ion implantation,silver and tantalum ratio,osteogenic enhancement,antibacterial responses

Tantalum (Ta), as an ideal new graft material, has the advantages of excellent corrosion resistance and cell compatibility. However, its high elastic modulus and high density (186 GPa, 16.6g/cm³) are much higher than that of natural bone, which limits the clinical application of bulk Ta. Compared with other commonly used medical metal materials, the elastic modulus of Ti-6Al-4V is similar to that of human bone. Therefore, Ti-6Al-4V was selected to combine with Ta to play the excellent biological properties of Ta. Although Ta has good cytocompatibility, its antimicrobial effect is unclear. Silver (Ag), as a commonly used antimicrobial agent, has been widely used to improve the antimicrobial properties of implants. It is hoped that the modified Ta membrane will not only have good biocompatibility, but also have excellent antimicrobial properties. Ti-6Al-4V is easy to precipitate toxic ions aluminum (Al) and vanadium (V) in the human body, so in this paper, a layer of TiN was deposited on Ti-6Al-4V by DC magnetron sputtering to prevent the precipitate of toxic ions, and then Ag and Ta were co-implanted into the titanium alloy with TiN coating in different ratios by plasma immersion ion implantation system (PIII). The results showed that Ag/Ta-TiN could (i) effectively prevent the precipitation of toxic ions Al³⁺ and V⁴⁺; (ii) effectively improve the corrosion resistance; (iii) enhance the cell compatibility; (iv) significantly improve the antimicrobial properties. In conclusion, the co-implanted of Ag and Ta doping can effectively improve the biocompatibility and antibacterial properties of titanium alloy, and the appropriate Ag/Ta ratio is the key.