Development of new Ti50Zr25Nb20Cu5–Ag high-entropy alloys with excellent antibacterial property, osteo-conductivity and biocompatibility in vitro and in vivo

Abstract

• New Zr–Ti–Nb–Cu–Ag high-entropy alloys(HEAs), especially HEACu 2.5 Ag 2.5 showed better antibacterial ability against Staphylococcus aureus than Ti–6Al–4V. • Excellent osteo-conductivity of HEAs was observed in vitro. • HEACu 2.5 Ag 2.5 can prevent serious bacterial infections peri-implants, with a lower PCT in infection models. A new series of medical antibacterial high-entropy alloys (HEAs) with composition Ti 50 Zr 25 Nb 20 Cu 5– x Ag x ( x = 0 at.%, 1 at.%, and 2.5 at.%) were developed by arc-melting the mixture of pure elements under a high-purity argon atmosphere. The cytotoxicity, osteo-conductivity, and antibacterial properties of these HEAs were systematically investigated in vitro, along with their in-vivo biocompatibility and antibacterial properties. These HEAs, especially Ti 50 Zr 25 Nb 20 Cu 2.5 Ag 2.5 , showed better antibacterial ability against Staphylococcus aureus than Ti–6Al–4V, which has a nearly 99% antibacterial rate in vitro. Moreover, ion release and cytotoxicity tests showed that these HEAs had excellent biosafety, similar to or better than that of Ti–6Al–4V. Osteoblasts were used to evaluate the osteogenic activity of these HEAs, and good osteo-conductivity was observed in vitro. In a Sprague-Dawley rat infection model, Ti 50 Zr 25 Nb 20 Cu 2.5 Ag 2.5 showed remarkable antibacterial properties compared to Ti–6Al–4V. The in-vivo biocompatibility results showed that Ti 50 Zr 25 Nb 20 Cu 2.5 Ag 2.5 did not increase biotoxicity compared to Ti–6Al–4V. The excellent biocompatibility and antibacterial properties of the Ti–Zr–Nb–Cu–Ag HEAs are expected to enable the prevention of periprosthetic/peri-implant infections in the future.