One-pot preparation of hydrogel wound dressings from Bletilla Striata polysaccharide and polyurethane with dual network structure

• Bletilla Striata was integrated into hydrogels in a single one-pot preparation. • The hydrogel showed excellent ability in promoting wound healing. • The hydrogels have excellent biocompatibility and hemostatic property. • Dual network structure was formed simultaneously in the hydrogel. Hydrogel wound dressings integrating Bletilla Striata Polysaccharide (BSP) are promising in clinical treatment because of their high hemostatic ability, high absorption to exudates, softness, non-toxicity, and non-irritating property. However, complex procedures are always needed to fabricate such hydrogels. Herein, a one-pot method is proposed to prepare hydrogel wound dressings integrating BSP by simply mixing the BSP aqueous solution with isocyanate terminated polyurethane. During mixing, the BSP macromolecules function as a chemical crosslinker by reacting with the terminal isocyanate groups of the polyurethane chains. Moreover, the urea groups newly formed facilitate the intermolecular hydrogen bonding and the formation of a physical network. The results of in vivo and in vitro experiments indicate that the PUB hydrogel dressings can rapidly absorb tissue exudates and have good retention ability. Furthermore, the hydrogels can remove radicals, promote blood coagulation, and have good biocompatibility. Most importantly, the PUB hydrogel dressings show excellent ability in promoting wound healing. Compared to the conventional gauze, the wound surface area of mice treated with PUB hydrogel is significantly reduced on day 3 after surgery, and there are more newly grown capillaries, lymphatics, and sweat glands in the PUB group.