Improved Diabetic Wound Healing via Flower Extracellular Vesicles and Carbon-Dot-Infused Alginate-Polyethylenimine Antibacterial Hydrogel

Diabetic wounds lead to substantial challenges in healthcare systems due to prolonged healing and susceptibility to debilitating bacterial infections. Traditional wound dressings, designed to regenerate wound voids and aid healing, often lack antibacterial properties. In this study, we present a syringe-injectable hydrogel (HG) infused with rose-petal-derived extracellular vesicles (REVs) and fluorescent carbon dots (CDs), which exhibit intrinsic antibacterial activity. The HG matrix was created by combining oxidized sodium alginate (OA) with branched polyethylenimine (PEI). This formulation selectively targets Gram-negative bacteria through strong physical and mechanical interactions while preserving human erythrocytes, as confirmed by hemolytic assays. Using a Wistar rat type 1 diabetic model, we demonstrated that the HG effectively eradicates E. coli at the application site, ensuring slow release and retention of REVs and CDs at the wound site, causing minimal inflammation. REV-CD-HG represents a scalable, cost-efficient, and innovative wound dressing with promising clinical applications.