Machine learning-assisted exploration and experimental assessment of β-type Ti_54-xZr₁₅Nb₁₄Mo₁₇Cu_x alloy with an ultra-low modulus for orthopedic applications

Implant-related infections are a significant and urgent problem in clinical medicine, which need to be addressed for a long time. Here, we designed a new type of low-cost, low elastic modulus, non-toxic, and easily manufacturable Ti–Zr–Nb–Mo series biomedical β-Ti alloy through machine learning methods and introduced Cu elements to impart antibacterial functionality to the alloy. The Ti_54−xZr₁₅Nb₁₄Mo₁₇Cu_x (x = 1, 3, 5, 7 at.%) alloys achieved excellent mechanical properties with an ultra-low modulus. Moreover, the Ti_54−xZr₁₅Nb₁₄Mo₁₇Cu_x alloys can inhibit both Staphylococcus aureus (Gram-positive bacteria) and Escherichia coli (Gram-negative bacteria). The potent antibacterial effect originates from the disruption of the bacterial cell wall structure induced by the reactive oxygen species (ROS). In addition, the Ti_54−xZr₁₅Nb₁₄Mo₁₇Cu_x alloys also exhibit excellent biocompatibility performance, which is beneficial for the clinical application. This work suggests that Ti_54−xZr₁₅Nb₁₄Mo₁₇Cu_x alloy implants have potential practicality in treating orthopedic infections.