Background: Bad wound healing increases the burden to the patient and health care services. So any technology that improves the healing process has the potential to save billions in annual health care costs and preserves the patient quality of life. Silver nanoparticles (AgNps) have become of interest in biomedical applications, because of their antibacterial, antifungal, antiviral and anti-inflammatory activity.
Aim: was to investigate the role of AgNps on the healing process of skin wounds in adult male albino rats.
Material & Methods: 72 male albino rats were subjected to excisional skin wounds 1.5 cm in diameter on their mid-backs. Then rats were divided into 4 groups 18 rats each; Group I(control): skin wounds were left to heal naturally. Group II: treated with methylcellulose hydrogel, Group III: treated with silver sulphadiazine
(dermazine cream) and Group IV: treated with AgNps in methylcellulose hydrogel. For each group 6 rats were sacrificed on 3rd, 7th and 14th day post-wounding. Skin specimens from all groups were processed for paraffin blocks. Sections were stained with Hx& E & Mallory's trichrome and immune-stained with vascular endothelial growth factor (VEGF). Using image analysis software, the number of macrophages, newly formed blood vessels & fibroblasts as well as area % of collagen fibers deposition were assessed and statistically analyzed.
Results: In AgNps treated group re-epithelialization started on day 3 post-wounding and complete epithelialization and regeneration of the dermis was observed on day 14. The granulation tissue filling the wound area contained macrophages, newly formed blood vessels, fibroblasts and collagen fibers. The number of macrophages was statistically highest with significant difference in AgNps treated group (group IV) on day 3 post-wounding then was the lowest on days 7 and 14 compared with other groups. Neovascularization started on day 3 in all groups but was prominent on group as proved by results of VEGF immune staining. The newly formed blood vessels declined on day 14 in AgNps treated group and remained high in silver sulphadiazine group and showed maximum density in control group. The number of fibroblasts in group IV was maximum on day 7 post-wounding & decreased to minimum on day 14. The percent of collagen fibers deposition was statistically maximum in AgNps treated group with significant difference across all periods of the study compared to other groups. Conclusion: AgNps accelerated skin wound healing in rats.