Bletilla striata polysaccharide - waterborne polyurethane hydrogel as a wound dressing

Polysaccharides are widely used in biomedicine because of their unique biological activity, low costs, and easy-to-obtain. In this paper, Bletilla striata polysaccharide (BSP) was integrated into waterborne polyurethane (WPU) to prepare a series of WPU-BSP (WPUB) hydrogels. The hydrogels showed good compressive strength, water absorption and retention ability, which are favorable for wound healing. Among them, the WPUB4 gel has the best comprehensive performances, including a compressive strength of 1.07 MPa, a swelling rate of 16.3, a reasonable WVRT of 2013 g/m²/day, and a long water retention time. About the in vitro biocompatibility, moreover, the WPUB4 hydrogel has a low hemolysis rate of 2.47%, a hydroxyl radical clearance rate of 35.5%, and little cytotoxicity with cell viability of 101.4%. Most importantly, the WPUB hydrogel dressings showed excellent ability in promoting wound healing. Compared to the conventional gauze, the wound surface area of mice treated with WPUB hydrogel was significantly reduced on day 3 after surgery and the wounds were healed on day 7. The new skin had a thicker epidermis and more capillaries. The WPUB hydrogels integrating BSP are promising to function as wound dressings.