A Novel Composite Biomaterial Made of Jellyfish and Porcine Collagens Accelerates Dermal Wound Healing by Enhancing Reepithelization and Granulation Tissue Formation in Mice.

Background and Objective: Impaired dermal wound healing represents a major medical issue in today's aging populations. Granulation tissue formation in the dermis and reepithelization of the epidermis are both important and necessary for proper wound healing. Although a number of artificial dermal grafts have been used to treat full-thickness dermal loss in humans, they do not induce reepithelization of the wound, requiring subsequent epithelial transplantation. In the present study, we sought a novel biomaterial that accelerates the wound healing process. Approach: We prepared a composite biomaterial made of jellyfish and porcine collagens and developed a hybrid-type dermal graft that composed of the upper layer film and the lower layer sponge made of this composite biomaterial. Its effect on dermal wound healing was examined using a full-thickness excisional wound model. Structural properties of the dermal graft and histological features of the regenerating skin tissue were characterized by electron microscopic observation and immunohistological examination, respectively. Results: The composite biomaterial film stimulated migration of keratinocytes, leading to prompt reepithelization. The regenerating epithelium consisted of two distinct cell populations: keratin 5-positive basal keratinocytes and more differentiated cells expressing tight junction proteins such as claudin-1 and occludin. At the same time, the sponge made of the composite biomaterial possessed a significantly enlarged intrinsic space and enhanced infiltration of inflammatory cells and fibroblasts, accelerating granulation tissue formation. Innovation: This newly developed composite biomaterial may serve as a dermal graft that accelerates wound healing in various pathological conditions. Conclusion: We have developed a novel dermal graft composed of jellyfish and porcine collagens that remarkably accelerates the wound healing process.