A multifunctional composite hydrogel with natural polymer silk fibroin and gelatin for promoting chronic wound healing.

The skin, being the largest organ of the human body, plays a pivotal role as a protective barrier against infections. Due to persistent infection and inflammation, chronic wounds pose a significant challenge. In the study, GelMA and SilMA hydrogels were synthesized using natural biopolymers gelatin and silk fibroin as raw materials. Honokiol and cobalt ions are mixed in proportion to form a composite hydrogel. Honokiol has powerful anti-inflammatory, antioxidant and chronic wound healing capabilities, while cobalt ions can promote vascular regeneration by activating the hypoxia-inducible factor pathway. The GSHC-n (honokiol/cobalt ion/GelMA-SilMA composite hydrogel, n represents different concentrations of honokiol and cobalt) composite hydrogel showcases favorable physical properties, biocompatibility, and antioxidant and antibacterial effects. Using a diabetic rat full-thickness skin defect model, wound healing was assessed, and its effectiveness in promoting chronic wound healing was remarkable. The natural polymer composite hydrogel, which incorporates dual drug loading, can achieve complete wound healing within 15 days. Its overall effectiveness surpasses that of the control product (silver ion dressing). In summary, this study offers competitive biomaterials that can accelerate the healing of chronic wounds.