Efficacy of silver-coated dressings as bacterial barriers in a rodent burnsepsis model

This study was designed to assess the efficacy of silver-coated dressings i n preventing Pseudomonas aeruginosa-related burn wound mortality in rats. I nfection by P. aeruginosa remains a significant cause of burn wound sepsis. Antibiotic therapy has not been as successful as anticipated in controllin g these organisms, prompting continued research into other treatment modali ties, including topical agents, to prevent or reduce infection. Using a mod ified Walker-Mason technique, burn wounds were induced on rats by exposing an area of dorsal skin to boiling water for 12 seconds. Burn sites were cov ered with vehicle dressings, with vehicle dressings saturated with AgNO3, o r with silver-coated dressings, and inoculated with P. aeruginosa. A Burn C ontrol group and Infection Control group were also included. Mortality was monitored daily and body weight gain was assessed at several intervals thro ughout the 15-day post-wounding study. Mean percent survival of rats receiv ing the silver-coated dressings was 85 percent compared to five percent in the Infection Control group and zero percent in the Silver Nitrate Dressing and Dressing Control groups. Rats in all infected groups lost weight durin g the first three days, but mean body weight loss was significantly greater in AgNO3 and Dressing Control groups than in Silver-Coated Dressing groups . Mean body weights of animals in the Silver-Coated Dressing group were com parable to Burn Control rats at Day 15. The use of the dressings coated wit h nanocrystalline silver significantly improved rat survival in this animal model.