Healing efficacy and dermal toxicity of topical silver nanoparticles-loaded hydrogel in Sprague–Dawley rats

Traumatic wounds are the wounds that damage both the skin and the underlying tissues. Bacterial load in wounded tissue triggers elongation of the inflammation phase of wound healing. In case of excessive inflammation, the wound may undergo delayed healing that can lead to complications such as sepsis or amputation. In the present work, a hydrogel using green-synthesized silver nanoparticles (AgNPs) was synthesized and characterized in terms of homogeneity, viscosity, spreadability, excipient compatibility, etc. The hydrogels containing different percentages of AgNPs were tested for healing efficacy in full-thickness excision wound model in adult female Sprague–Dawley (SD) rats. Safety study of hydrogels was performed in SD rats as per the OECD guideline 410. The prepared hydrogels were stable for over 3 months and remain intact on parameters such as homogeneity, pH balance, good spreadability, and extrudability. Healing efficacy study showed that an increased amount of AgNPs in hydrogel enhanced wound contraction over 100% with increased tensile strength and dense aligned collagen fibers in treated wound tissues as compared to standard (silver sulfadiazine), placebo, and sham groups. Dermal toxicity studies showed that there were no signs of irritation, inflammation, and edema on the dorsum of SD rats. Besides, there was no local and systemic toxicity in hydrogel-treated groups.