In vitro and in vivo characteristics of frozen/thawed neonatal pig split-skin strips: A novel biologically active dressing for areas of severe, acute or chronic skin loss

The recurrent shortage of human skin autografts or allografts used to close extensive wounds has rekindled the search for feasible alternatives. In the past, adult pig skin was a popular biological dressing, yet doubts regarding its benefits have induced most people to abandon its use. Here we investigated the aptness of neonatal pig split-skin (NPSS) strips to be used as a novel kind of temporary dressing for areas of skin loss. NPSS strips are able to be prepared in bulk amounts, stored at −80°C for up to six months, and recovered by swift thawing at 45°C with no change in histological structure. When set into organ cultures in vitro for up to three weeks, these frozen/thawed NPSS strips exhibited both a skin-typical energy-linked metabolism (i.e., a predominant consumption of L-glutamine instead of glucose), and an enduring ability to secrete cytokines/chemokines such as IL-1α, IL-6, GM-CSF, and TNF-α; all features alike in quantitative terms to those exhibited by freshly prepared NPSS strips directly set into culture. Moreover, once applied as temporary dressings onto deep burn wounds in vivo, frozen/thawed NPSS strips produced, for at least seven days, porcine IL-1α, IL-6, GM-CSF, TNF-α, and TGF-β; the cytokines/chemokines importantly involved in wound healing. Hence, frozen/thawed NPSS strips not only are capable of closing extensive areas of skin loss, but even release several cytokines/chemokines beneficial to tissue regeneration and repair.