Comparison of three different skin substitutes in promoting wound healing in an ovine model

Skin substitutes are designed dressings intended to promote wound closure. In previous in vitro and in vivo studies on small animal, an acellular skin patch made of collagen hydrogel with dermal fibroblast conditioned medium (Col-DFCM), a collagen sponge scaffold with freshly harvested skin cells (OTC), and a platelet-rich-plasma gel with freshly harvested skin cells (PRP) have been developed and tested for immediate treatment of full-thickness wound. However, to determine the safety and efficacy of these skin patches for clinical applications, further study in a large animal model is needed. The aim of this study is to evaluate the potential of Col-DFCM, OTC and PRP in treating full-thickness wound in an ovine model via histological analysis and immunohistochemistry staining were performed, with the untreated (NT) group serving as the control. Gross examination was conducted on day 7, 14 and 21 to determine the wound closure rate. The findings of percentage of wound size reduction showed that the wound healed fastest in the presence of Col-DFCM (91.34 ± 23.35%) followed by OTC (84.49 ± 23.13%), PRP (77.73 ± 20.9%) and NT group (73.94 ± 23.71%). Histological evaluation with Hematoxylin & Eosin (H & E) and Masson's trichrome staining was used to study the structure of the wound area. The results showed that OTC treated wound was more mature as indicated by the presence of a thinner epidermis followed by the Col-DFCM, PRP and NT group. Immunohistochemistry analysis also confirmed the integrity and maturity of the regenerated skin, with positive expression of cytokeratin 10 (CK10) and involucrin in the epidermal layer. In conclusion, Col-DFCM, OTC and PRP treatments promote healing of full-thickness wound and have the potential to be used clinically for rapid treatment of full-thickness wound.