Evaluation of a Sol-Gel Zirconia-Silver Coating for Titanium Implants: Assessing Biocompatibility, Osseointegration, and Enhanced Short-Term Antibacterial Efficacy.

Abstract

Implant-associated infections remain a major cause of failure in titanium-based orthopedic devices, often compromising long-term clinical outcomes and necessitating revision surgeries. Surface modification strategies that provide antibacterial protection while preserving osseointegration are therefore highly desirable. The aim of this study was to develop and evaluate a multifunctional titanium surface capable of preventing bacterial colonization without impairing biological integration. A titanium surface was engineered using sol-gel technology incorporating silver nanoparticles (Solgel_Ti). Antibacterial performance was assessed through microbiological analyses against Staphylococcus aureus, a clinically relevant pathogen in orthopedic implant infections. In vitro biological safety was evaluated by cytocompatibility assays and Ames's mutagenicity test. The in vivo performance of the coating was investigated using a rat femoral implantation model, with implants analyzed after 90 days through histological and histomorphometric assessments to quantify bone-to-implant contact and new bone formation. Solgel_Ti demonstrated a significant short-term antibacterial effect against S. aureus when compared with uncoated titanium controls. In vitro analyses confirmed a high biological safety profile, showing excellent cytocompatibility and no evidence of mutagenic activity. In vivo evaluations revealed that Solgel_Ti-coated implants supported effective osseointegration, with bone-to-implant contact and new bone formation comparable to those observed for unmodified titanium. No adverse tissue reactions or signs of impaired bone healing were detected. These findings indicate that Solgel_Ti represents a promising dual-functional surface modification strategy that successfully combines antibacterial activity with preserved osseointegration. This approach offers a viable pathway for the development of safe, infection-resistant orthopedic implants with long-term clinical potential.