Enhancing antibacterial performance of powder metallurgy-fabricated Ti, Ti-15Mo, and Ti-45Zr alloys through small liquid metal gallium additions in biomedical applications

This study investigates the influence of small liquid metal gallium additions (1, 1.5, 2, and 2.5 wt%) on the antibacterial performance of Ti, Ti-15Mo, and Ti-45Zr alloys fabricated by the powder metallurgy method. The alloys were manufactured by sintering at 1250 °C to improve the antibacterial activity of Titanium and its alloys in biomaterial applications. X-ray diffraction (XRD) was used to identify the dominant compounds and phases after adding liquid gallium metal, and the antibacterial activity was also tested; the results indicate an increase in the Zone of inhibition of Ti, Ti-15Mo, and Ti-45Zr with increasing gallium/Ga content, where the Zone of inhibition increased by approximately 12, 12.5 and 18% for Ti, Ti-15Mo, and Ti-45Zr, respectively. This is attributed to Ga³⁺, which disrupts iron-dependent enzymes and metabolic pathways (e.g., DNA synthesis, electron transport), inhibiting bacterial growth. Adding Ga alters the alloy's surface topography and chemistry, reducing bacterial adhesion. A smoother or more hydrophobic surface prevents bacterial colonization and biofilm formation. Titanium and its alloys with liquid gallium metal were also shown to be non-toxic biomaterials with biocompatibility properties for MCF-10 cells. Ga additives for Ti, Ti-15Mo, and Ti-45Zr improve antibacterial performance, making these alloys promising for medical implants and reducing infection risks without relying on antibiotics. Further optimization of Ga concentration and release kinetics is critical to balance efficacy and biocompatibility.