Diabetic hyperglycemia delays wound healing, leading to serious consequences. Topical antibiotics can reduce the risk of a wound infection during healing; nevertheless, the microbial fight against antibiotics brings about public health challenges. Anti-microbial peptides (AMPs) belong to a novel class of drug that is used to prevent and treat systemic and topical infections. The aim of the current work was to achieve better wound healing in diabetic rats by conjugating the anti-microbial peptide "apamin" (APA) with the broad-spectrum antibiotic "ceftriaxone" (CTX) to form a nanocomplex. The CTX-APA nanoconjugate formulation was optimized using a Box-Behnken design. The optimized CTX-APA nanoconjugate formulation was evaluated for its size and zeta potential, and was then examined using transmission electron microscopy (TEM). The CTX-APA nanoconjugate was loaded onto a hydroxypropyl methylcellulose (2% w/v)-based hydrogel. It was observed that the application of the CTX-APA nanocomplex on the wounded skin of diabetic rats accelerated the regeneration of the epithelium, granulation tissue formation, epidermal proliferation, and keratinization. The nanocomplex was capable of significantly reducing the expression of tumor necrosis factor alpha (TNF-α) and interleukin 6 (IL-6), while increasing the expression of transforming growth factor beta-1 (TGF-β1) as well as the angiogenic markers: hypoxia-inducible factor 1-alpha (HIF-1α) and vascular endothelial growth factor (VEGF). Conclusively, the application of an ion-paired CTX-APA nanocomplex enhances wound healing in diabetic rats.
Keywords: anti-microbial peptides; apamin; ceftriaxone; diabetic wounds; hydrogel; optimization; three-factor Box–Behnken design.