Diabetes mellitus causes impaired wound healing. In this study, the potential wound healing activities of topical chitosan/ Zinc oxide nanocomposite membrane and local insulin injection in diabetic rats were evaluated. Diabetes was induced by a single IP injection of Streptozotocin (STZ) at a dose of 50mg/kg b.wt. Forty-eight male rats were divided into Six groups. Group I: control wounded, non-treated, non-diabetic rats, Group II: wounded diabetic non-treated, Group III: Normal wounded rats treated with chitosan/ Zinc oxide nanocomposite membrane, Group IV: Diabetic wounded treated with chitosan/ Zinc oxide nanocomposite membrane rats, Group V: wounded diabetic rats treated with local insulin injection, Group VI: Wounded diabetic rats treated with chitosan/ Zinc oxide nanocomposite membrane and local insulin injection. After 14 days of wound treatment, rats were euthanized and the skin tissue was collected for (EGF), (PDGF), (MMP9) and miRNA 21 gene expression analysis. A significant down-regulation of EGF, PDGF and miRNA 21 with up-regulation in MMP 9 were observed in diabetic non treated wounds as compared with control wounded. Meanwhile, a significant increase of EGF, PDGF and miRNA 21 with decrease in MMP 9 gene expression was observed in insulin, Chitosan/ZnO membrane treatment alone or in combination in wounded diabetic rats. Conversely, MMP9 was significantly down regulated after different treatments. The finding indicated that topical Chitosan/ZnO nanocomposite membrane and insulin injection exhibited a great effect on the acceleration of diabetic wound healing via increasing proangiogenic effect, re-epithelialization, and remodeling of ECM .

Diabetes put off healing method as it impairs every section of wound restoration i.e., hemostasis, irritation, proliferation, and remodeling section. Insulin and a natural polymer of chitosan (CS) can potentially repair the integrity of broken pores and skin in the field of wound repair. Zinc oxide (ZnO) possesses both antibacterial and anti-inflammatory properties and accelerates the wounds restoration. The wound recovery capability of insulin injection with chitosan/ZnO nanocomposite membrane in diabetic rats were evaluated. Diabetes was induced by Streptozotocin (STZ) administered intraperitoneally (i.p.) as one dose (50 mg/kg b. wt.). Forty-eight male rats were divided into six groups. Group I: control wounded, non-treated, non-diabetic rats, Group II: wounded diabetic non treated, Group III: Normal wound treated with chitosan/zinc oxide nanocomposite membrane, Group IV: Diabetic wounded treated with chitosan/zinc oxide nanocomposite membrane, Group V: wounded diabetic rats treated with local insulin injection, Group VI: wounded diabetic treated with chitosan/zinc oxide nanocomposite membrane and local insulin injection. A significant decrease in (PI3K), (MAPK) genes expression in addition to miRNA 125 and miRNA 132 in skin tissue of diabetic wounds compared with normal wound. However, increase in PI3K, MAPK, miRNA 125 and miRNA 132 genes were observed in diabetic wounds treated with chitosan/ZnO nanocomposite membrane or local insulin injection as compared to diabetic wounds non treated. The present data indicated that local insulin injection in wound area with chitosan/ZnO nanocomposite membrane might activate the PI3K/MAPK signaling pathway and some miRNA that promote and accelerates diabetic wound healing.

Diabetic wounds regularly take a longer time to heal than wounds in healthy animals. Chitosan (CS) interacts with many cellular processes and it elevates the necessary expression of growth factors in wound healing. The topical utility of zinc was suggested to limit inflammation, enhance re-epithelialization, and lower bacterial growth in chronic wounds. Also, there is evidence that insulin has effects on healing wounds. Therefore, the wound healing potential of insulin injection with CS/Zno nanocomposite membrane in diabetic rats was assessed. Diabetes was induced by a single IP injection of Streptozotocin (STZ) at a dose of 50 mg/kg b.wt. after diabetes induction. on the back of eacfull, a full-thickness excisional wound had been made. Forty-eight male rats were divided into Six groups. Group I: normal wound non-treated, Group II: diabetic wound non-treated, Group II: normal wound treated with CS /ZnO membrane, Group IV: diabetic wound treated with CS/ZnO membrane, Group V: diabetic wound and local insulin treatment (2 U/rat per day), Group VI: diabetic wound treated with Chitosan /ZnO membrane and insulin injection. The findings revealed a notable decline in Basic fibroblast growth factor(bFGF), Vascular endothelial growth factor (VEGF), Transforming growth factor β(TGF-β), and α-Smooth muscle actin(α-SMA) in diabetic non-treated wounds. However, treatment with CS/ZnO nanocomposite membrane or local insulin injection exhibit a significant increase. Conclusively, CS/ZnO nanocomposite membrane and local insulin accelerate diabetic wound healing through activation of growth factors production and stimulating the proliferation of inflammatory cells during the healing process and angiogenesis, followed by wound maturation.