Synergistic antibacterial coating on titanium bone nails using ZIF-8 and vancomycin for preventing implant-associated infections

Implant-associated infections (IAIs) pose a major challenge in orthopaedic surgery, often leading to revision procedures and increased morbidity. This study introduces a novel antibacterial coating on titanium bone nails (Ti-LOK) fabricated via a one-pot synthesis of zeolitic imidazolate framework-8 (ZIF-8) loaded with vancomycin (Van). The coating, Ti-LOK@ZIF-8/Van, leverages the porous structure of ZIF-8 for pH-responsive Van release and zinc ion-mediated antimicrobial effects. Characterization via SEM, EDS and FTIR confirmed the uniform crystalline morphology (100–200 nm particles), elemental integration and presence of functional groups. Antibacterial assays against Staphylococcus aureus and Escherichia coli demonstrated near-complete inhibition, with >99% reduction in bacterial counts and extensive cell death observed via live/dead staining. Morphological analysis revealed bacterial membrane disruption and lysis on the coated surfaces. The coating exhibited excellent cytocompatibility with MC3T3-E1 cells (>90% viability). This synergistic system addresses IAI limitations, offering a biocompatible, responsive platform for enhanced orthopaedic outcomes.