The Utility of Silk-elastin Hydrogel as a New Material for Wound Healing

Cutaneous ulcers are treated with dressing materials and/or ointments to keep the wound in an appropriately moist environment. However, chronic cutaneous ulcers commonly have bacterial colonization that can cause local infection in such an environment. Therefore, the dressing materials and/or ointments should have antibacterial potency to treat chronic ulcers. Acute cutaneous wounds, by contrast, heal rapidly without local infection. The aim of treating acute cutaneous wounds is therefore not only wound closure but also preventing scar contracture after wound healing. However, no dressing materials or ointments available at present are simultaneously effective for preventing infection in chronic ulcers and reducing wound contracture in acute ulcers. Silk-elastin is a recombinant protein polymer with repeating units of silk-like and elastin-like blocks. Silk-elastin solution can self-assemble from a liquid to a hydrogel. We preliminarily reported that silk-elastin hydrogels have the potential to accelerate wound healing in decubitus ulcers of diabetic mice, which are animal models of severe, intractable cutaneous ulcers. In the present study, we examined the effects of silk-elastin hydrogels in chronic and acute ulcer models in comparison with conventional products (carboxymethyl cellulose gel). Silk-elastin hydrogels resulted in significantly higher epithelialization rates than conventional hydrogels in both the chronic and acute ulcer models and significantly larger areas of granulation tissue in acute ulcer models. These results show that silk-elastin hydrogel is a promising material for promoting the healing of cutaneous wounds, including decubitus ulcers, chronic ulcers, and acute ulcers.