An Autologous Dermal–Epidermal Composite Engineered Skin Repairs Wounds in a Pig Model

(1) Background: Meshed split skin grafting (SSG) still remains the gold-standard of care for deep wound treatment. The aim of this study was to evaluate an autologous bioengineered dermal–epidermal composite skin for treating full-thickness wounds in a porcine model using a clinically relevant two-stage grafting approach. (2) Methods: Multiple full thickness wounds were created on the dorsal sites of animals. Wounds were initially grafted with a polyurethane dermal template, followed three weeks later by either Platelet hydroGel–Pig Skin Equivalent (PG-PSE) or meshed SSG control. Human platelet lysate was also assessed as a substitute for foetal calf serum during skin maturation. (3) Results: By two weeks post grafting, epidermisation of PG-PSE–treated wounds was comparable to SSG-treated wounds. EdU labelling confirmed early engraftment and contribution of graft-derived cells to both neo-epidermis and neo-dermis. Immunofluorescence staining for vimentin+ fibroblasts and cytokeratin 5+ keratinocytes demonstrated formation of a neo-dermis and a hyperproliferative neo-epidermis enriched in progenitor keratinocytes, with rete ridge architecture indicative of dermal–epidermal maturation. Robust neovascularisation was observed in both papillary and reticular neo-dermis, with platelet lysate–matured grafts showing greater microvessel formation than foetal calf serum–matured grafts. Collagen deposition in PG-PSE grafts, particularly collagen I in the papillary neo-dermis, remained lower than in SSG-treated wounds, consistent with ongoing integration. However, collagen type I/type III composition in the reticular neo-dermis was largely comparable between PG-PSE and SSG, suggesting that bioengineered grafting does not alter dermal template maturation. (4) Conclusion: Overall, autologous dermal–epidermal bioengineered skin effectively vascularises and repairs wounds over a dermal template. Platelet lysate is a promising alternative to foetal calf serum, although PG-PSE may require longer for complete dermal maturation and warrants further long-term evaluation.