Controlled Bimetallic Ta–Ag Nanoparticles via In Situ Thermal Plasma with Osteogenic and Antibacterial Properties for Orthopedic Applications

Silver (Ag) can endow tantalum (Ta) with antibacterial properties, which is crucial for bone implant applications. While the osteogenic and antibacterial properties of bimetallic Ta–Ag nanoparticles (NCs) have not been studied, in this paper, Ta–Ag NCs with different Ta contents were first synthesized by the nucleation growth of gaseous atoms, an arc-discharge plasma method under a mixed atmosphere of hydrogen and argon. The as-prepared Ta–Ag NCs consist of Ta phases and Ag phases, and the grain sizes are 10–80 nm and gradually enlarged with the increase of Ta ratio. The antibacterial efficiency of Ta–Ag NCs is positively proportional to Ta content, and the bacteriostatic mechanism is attributed to the galvanic corrosion effect of the Ta–Ag interface. Furthermore, the Ta–Ag NCs possess good cytocompatibility and can reduce pro-inflammatory cytokines, increase anti-inflammatory cytokines, and promote the expression of osteogenetic genes. Meanwhile, the comprehensive performance is enhanced with an increase in Ta content. Altogether, such Ta–Ag NCs show greater potential in orthopedic applications.