Antibacterial Efficacy and Biocompatibility of HiPIMS-Ag Films for Prosthetic Application

Implant-associated infections (IAIs) remain a major cause of orthopedic implant failure, motivating the development of surface coatings that deliver durable antibacterial activity without compromising host compatibility. Here, we deposit silver (Ag) thin films onto commercially pure titanium (Ti) using high power impulse magnetron sputtering (HiPIMS) and assess their antibacterial performance and osteoblast cytocompatibility. Film formation, morphology and crystallinity were characterized by electron microscopy and X-ray diffractometry, while interfacial integrity was probed using ASTM D3359 cross-cut and VDI 3198 Rockwell-C indentation. Antibacterial activity against Escherichia coli and Staphylococcus aureus was quantified by culture-based enumeration, and Ag+ release was measured by ICP-MS. HiPIMS enabled rapid formation of dense, continuous and crystalline Ag films with excellent adhesion. Even ultrathin coatings (~7 nm) produced strong antibacterial effects (activity value > 2.0) while releasing controllable trace Ag+ (ultimately 0.43 ppb/day), and osteoblast assays indicated no cytotoxicity under the tested conditions. The results show that HiPIMS-Ag achieves a favorable balance between antimicrobial efficacy and biocompatibility at low thickness, supporting its use as a robust antibacterial surface for Ti implants and providing a foundation for translation to device level and in vivo studies.