Accelular Dermis Promotes Neovascularization and Epidermal Regeneration: Implications for Wound Healing
Liana M. Lugo, Surgery, University at Buffalo, State University of New York, Buffalo, NY 14203 and Stelios T. Andreadis, Chemical and Biological Engineering, SUNY-Buffalo, 908 Furnas Hall, Buffalo, NY 14260-4200.
Despite significant advances in management of severe wounds such as burns and chronic ulcers, autologous split-thickness skin grafts are still the gold standard of care. The main problems with this approach include pain and discomfort associated with harvest of autologous tissue, limited availability of donor sites and the need for multiple surgeries. Although tissue engineering has great potential to provide alternative approaches for tissue regeneration several problems have hampered progress in translating technological advances to clinical reality. Specifically, engineering of skin substitutes requires long culture times and delayed vascularization after implantation reduces graft survival. To address these issues we developed a novel two-prong strategy for tissue regeneration in vivo: (i) vascularization of acellular dermal scaffolds by infiltration of angiogenic factors; (ii) generation of stratified epidermis by direct delivery of epidermal keratinocytes in vivo. Using athymic mouse as a model system we found that gene delivery from acellular human dermis enhanced the density and diameter of infiltrating blood vessels. Surprisingly, cell delivery resulted in fully stratified epidermis with normal spatiotemporal expression of differentiation markers including keratin-10, involucrin and fillagrin. This strategy promoted tissue regeneration in vivo with no need for engineering skin tissue in vitro and therefore, it may be useful for treatment of major wounds when skin donor sites are scarce and rapid wound coverage is required.