Polydopamine Microspheres Loaded with Antimicrobial Peptide HX-12C Pullulan/Gelatin Hydrogel for Burn Wound Healing

Burns are one of the most common causes of skin barrier damage and are prone to a range of problems, including wound infection. The development of a multifunctional dressing that is self-adhesive, anti-infective, and also provides sustained drug release is essential. In this study, polydopamine microspheres encapsulating an antimicrobial peptide were introduced into pullulan and gelatin hydrogels, and microsphere hydrogel composites were prepared in order to enhance the certain self-adhesive and antimicrobial properties. Antibacterial experiments showed that the composite hydrogel inhibited Staphylococcus aureus and Escherichia coli by 100%. The composite also showed good cytocompatibility, with cell survival rates above 90% in the AMP@PDA/Pu/Gel group when the microsphere concentration was 5 mg/mL. Mouse burn experiments showed that AMP@PDA/Pu/Gel hydrogels could also provide good bacterial inhibition. In addition, hydrogels reduced inflammation and promoted the formation of collagen and blood vessels. Furthermore, we selected the corresponding inflammatory factors (TNF-α, TGF-β1, TGF-β3) to test the anti-inflammatory properties of the composite hydrogel in burn wounds. The findings reveal that AMP@PDA/Pu/Gel hydrogels have good prospects for application in anti-infection treatment, wound repair and a type of burn wound dressing.