Calendula flower extract loaded PVA hydrogel sheet for wound management: Optimization, characterization and in-vivo study

Abstract

The aim of the present investigation was to prepare hydrogel sheet containing calendula flower extract and evaluate its stability, safety and wound healing activity in experimental rats. Hydrogel sheet was prepared by gamma irradiation technique and optimized using Box-Behnken design. The optimized formulation was analyzed for different physicochemical properties such as % gel fraction, hardness, pH, % fluid absorptivity, moisture vapor transmission rate, sterility, total flavonoid content, total phenolic content and antioxidant activity. The safety and efficacy of developed formulation was investigated by in-vitro cell culture experiments including MTT assay, scratch assay, in-vitro hemolysis study and in-vivo wound healing activity. No cell cytotoxicity and less than 1.5% hemolysis were observed with CFE loaded hydrogel sheet. In-vitro scratch assay on 3T3 Swiss albino cell line showed that the developed formulation promoted cell migration and proliferation better than placebo. The CFE loaded hydrogel sheet treated animals showed significant reduction in period of epithelization and wound contraction time as compared to non-treated and placebo formulation treated animals. The rate of wound contraction was significantly (p < 0.001) high in CFE loaded hydrogel sheet treated wounds (87.01%) when compared to control group (25.41%), placebo treated group (72.63%) and, marketed product treated group (84.0%) on day 21. The developed hydrogel sheet was stable as there were no significant changes in its physicochemical properties during stability studies.