A fucoidan-gelatin wound dressing accelerates wound healing by enhancing antibacterial and anti-inflammatory activities

Microbial infections and the slow regression of inflammation are major impediments to wound healing. Herein, a tilapia fish skin gelatin-fucose gum-tannic acid (Gel&Fuc-TA) hydrogel wound dressing (Gel&Fuc-TA) was designed to promote wound healing by mixing and reacting tannic acid (TA) with tilapia fish skin gelatin (Gel) and fucoidan (Fuc). Gel&Fuc-TA hydrogel has a good network structure as well as swelling and release properties, and shows excellent antibacterial, antioxidant, cell compatibility, and hemostatic properties. Gel&Fuc-TA hydrogel can promote the expression of vascular endothelial growth factor (VEGF), platelet endothelial cell adhesion molecule-1 (CD-31), and alpha-smooth muscle actin (alpha-SMA), enhance collagen deposition, and accelerate wound repair. Gel&Fuc-TA hydrogel can change the wound microbiome, reduce wound microbiome colonization, and decrease the expression of microbiome-related proinflammatory factors, such as lipopolysaccharide (LPS), Toll-like receptor 2 (TLR2), and Toll-like receptor 4 (TLR4). Gel&Fuc-TA hydrogel effectively regulates the conversion of wound macrophages to the M2 (anti-inflammatory phenotype) phenotype, decreases the expression of interleukin-6 (IL-6), interleukin-1 beta (IL-1 beta) and tumor necrosis factor-alpha (TNF-alpha), and increases the expression of arginase-1 (Arg-1), interleukin-10 (IL-10) and transforming growth factor-beta (TGF-beta), thereby reducing the inflammatory response. In summary, Gel&Fuc-TA hydrogel prepared using a rational green cross-linking reaction can effectively accelerate wound healing.