Antimicrobial effect of silver nanoparticles as a potential healing treatment for wounds contaminated with Staphylococcus aureus in wistar rats

Currently, the main challenges associated with conventional treatments for complex wounds include antibiotic resistance, persistent infections, delayed healing, pain and discomfort, lesion recurrence, and limited patient adherence. Silver nanoparticles (AgNPs) have demonstrated potential for bacterial control in contaminated wounds while promoting tissue regeneration. The aim of this study was to evaluate the bactericidal activity of AgNPs in wounds contaminated and non-contaminated with S. aureus. An aqueous suspension of AgNPs at a concentration of 117 μg/mL was synthesized by reducing silver nitrate in a medium containing tannic acid and sodium citrate. The resulting nanoparticles were spherical, with an average diameter of 24.3 ± 0.18 nm, a polydispersity index (PDI) of 0.25 ± 0.013, and a ζ-potential of −60.0 ± 3.07 mV. The bactericidal effect of AgNPs was observed at concentrations of 58.5 μg/mL for Escherichia coli and 6.74 μg/mL for S. aureus and Pseudomonas aeruginosa. Fibroblast viability (L929 cells) was maintained at confluence with AgNPs concentrations ranging from 0.1 μg/mL to 7.3 μg/mL. On the 7th day post-wound induction, animals treated with AgNPs exhibited 90 % re-epithelialization along with effective microbiological control. Histological analysis revealed a significant increase in fibroblast production in the treated groups compared to controls (p < 0.01). These results indicate that AgNPs hold promise for topical applications in bacterial control and wound healing.