Multifunctional Hydroxyapatite Coated with Gallium Liquid Metal-Based Silver Nanoparticles for Infection Prevention and Bone Regeneration

Implant-associated infections and inflammation during pre- and post-operative procedures remain significant challenges that reduce implant longevity. In this study, the uniques bioactive coatings derived from silver-gallium liquid metal particles (Ag-GaNPs) deposited uniformly over HAp scaffold (HAp-Ag-GaNPs) are developed. The HAp-Ag-GaNPs exhibit strong antimicrobial activities against Gram-negative Pseudomonas aeruginosa, Gram-positive Staphylococcus aureus (S. aureus), drug-resistant bacteria such as methicillin-resistant S. aureus, and persistent bacteria like small colony variant of S. aureus. The antibacterial mechanisms of HAp-Ag-GaNPs are multifaced, including reactive oxygen species within cells, leading to damage and leakage of cytosolic contents and reduced ATP levels. The synchrotron macro attenuated total reflectance – Fourier transform infrared microspectroscopy is utilized to understand the influence of HAp-Ag-GaNPs on lipids, proteins, and nucleic acids of pathogenic bacteria. Proteomic analysis reveals that HAp-Ag-GaNPs disrupt critical bacterial processes, including DNA replication, RNA transcription, protein synthesis, and energy metabolism, alongside inducing oxidative stress and membrane damage in bacteria. In addition, in vivo studies demonstrate reduced bacterial colonization and enhanced tissue integration at implant sites treated with HAp-Ag-GaNPs, further supporting their dual functionality. The findings highlight the potential of HAp-Ag-GaNPs as a next-generation biomaterial with dual antibacterial and osteogenic properties for clinical applications in orthopedic implants.