Influence of silver nanoparticles on post-surgical wound healing following topical application

Background: Prevention of surgical site infection and wound dehiscence are imperative and also challenging in clinical practice. This study examines the healing response of laparotomy wounds following application of silver nanoparticles. Materials and Methods: Dermal fibroblasts were exposed to incremential doses of silver nanoparticles and its effect on collagen synthesis and cytotoxicity was assessed. Laparotomy surgery was performed on rabbits and the operation site was treated topically either with silver nanoparticle once, or once daily for 14 days or with vehicle. Healing response and local tissue reaction was evaluated clinically by histopathology and scanning electron microscopy (SEM); microbial load on the operation site was assessed. Clinical tests and histopathology were performed to assess systemic toxicity. Results: Silver nanoparticles increased collagen expression from dermal fibroblasts and longer time exposure increased caspase 3 expression and produced cyotoxic effect with an IC50 of 0.16 mg/mL. Daily treatment of operation sites resulted in increased collagen deposition and improved wound healing, microbial load was reduced. Although a sub dermal edema was evident in histopatho logy, SEM showed normal architecture of cells with infiltration of lymphocytes. There was no systemic toxicity. Conclusions: Silver nanoparticles exhibit a positive influence on wound healing but its effect on local tissue remains a concern.