Topical delivery of chitosan-capped silver nanoparticles speeds up healing in burn wounds: A preclinical study

This study investigated the effects of topical application of chitosan-capped silver nanoparticles (Ch/AgNPs) on burn wound healing. The chitosan-capped silver nanoparticles were synthesized in one step from the silver nitrate, sodium borohydride, and chitosan and were characterized using transmission electron microscopy, fourier transform infrared spectroscopy, and X-ray diffraction methods. The antioxidant assay was performed to evaluate the scavenging rate. The effects of Ch/AgNPs on burn wound healing was also evaluated by histopathological, molecular, and biochemical evaluations after 7, 14 and 28 days of treatment in a rat model. In comparison to the negative control and silver sulfadiazine groups, the Ch/AgNPs treated wounds exhibited significantly lower inflammatory reaction as determined by the reduced level of interleukin-1 beta (IL-1 beta) and neutrophil counts. Treatment by Ch/AgNPs also significantly enhanced re-epithelialization, so that complete epithelialization was achieved in the lesions of the animals of this group, at the 7th day post-wounding. Rapid reepithelialization, improved granulation tissue formation, reduced IL-1 beta expression, mild inflammation, and increased transforming growth factor-beta 1 and basic fibroblast growth factor, at 7 days post-wounding, are convincing reasons to confirm this idea that Ch/AgNPs are effective in speeding up the wound healing stages. Our histopathological findings are in agreement with the molecular and biochemical results and strongly demonstrate that Ch/AgNPs stimulate burn wound healing by decreasing the length of repair phases. Therefore, on the basis of our findings, Ch/AgNPs can be a promising candidate in stimulating wound repair and regeneration.