Characteristics of novel Ti-10Mo-xCu alloys by powder metallurgy for potential biomedical implant applications

When biomaterials are implanted in the human body, the surfaces of the implants become favorable sites for microbial adhesion and biofilm formation, causing periimplant infection which frequently results in the failure of prosthetics and revision surgery. Ti-Mo alloy is one of the commonly used implant materials for load-bearing bone replacement, and the prevention of infection of Ti-Mo implants is therefore crucial. In this study, bacterial inhibitory copper (Cu) was added to Ti-Mo matrix to develop a novel Ti-Mo-Cu alloy with bacterial inhibitory property. Effects of Cu content on microstructure, tensile properties, cytocompatibility, and bacterial inhibitory ability of Ti-Mo-Cu alloys were systematically investigated. Results revealed that Ti-10Mo-1Cu alloy consisted of α and β phases, while there were a few Ti 2 Cu intermetallic compound existed for Ti-10Mo-3Cu and Ti-10Mo-5Cu alloys, in addition to α and β phases . Tensile strength of Ti-10Mo-xCu alloys increased with Cu content while elongation decreased. Ti-10Mo-3Cu alloy exhibited an optimal tensile strength of 1098.1 MPa and elongation of 5.2%. Cytocompatibility study indicated that none of the Ti-10Mo-xCu alloys had negative effect on MC3T3-E1 cell proliferation. Bacterial inhibitory rates against S. aureus and E. coli increased with the increase in Cu content of Ti-10Mo-xCu alloy, within the ranges of 20-60% and 15-50%, respectively. Taken together, this study suggests that Ti-10Mo-3Cu alloy possesses high strength, acceptable elongation, excellent cytocompatibility and bacterial inhibitory property is a promising candidate for biomedical implant applications.