Characterization of cutaneous wound healing in swine

The porcine excisional wound model is widely regarded as the most translationally relevant preclinical platform for studying human skin wound healing owing to its close anatomical and physiological similarity to human skin and thus can inform human studies. We conducted a detailed temporal analysis of wound healing in 6 Yorkshire pigs, each receiving twelve 20-mm full-thickness wounds. Blood, wound images, and biopsies from wound edges and centers were collected from postoperative days 1 to 21. All wounds fully epithelialized by day 21. Histology showed rapid neo-epithelial migration by day 1, with immune profiling through RNA sequencing and CIBERSORTx identifying an early predominance of neutrophils and reparative M2 macrophages. Immunostaining confirmed a progressive M2 shift, with increasing CD68+/Arg1+ cell ratios through day 15. Collagen dynamics revealed short collagen fiber deposition peaking from days 9-19 and transitioning to longer fibers by day 21. PGP9.5 staining demonstrated robust epidermal nerve regeneration from days 3 to 7. These data provide a detailed, multiparameter map of the immune; structural; and neural milestones in porcine wound healing, establishing baseline benchmarks for normal wound repair, supporting the development of machine learning tools for wound assessment.