Background: Deficiency of autologous skin for reconstruction of severe wounds is a major problem in plastic surgery. Autologous substitutes can provide additional coverage, but due to the duration of production, treatment is significantly delayed. The allogeneic approach offers a potential of having an off-the-shelf solution for the immediate application.
Methods: In this study, we assess the engraftment and immunogenicity of allogeneic bilayered bioengineered skin prepared by a self-assembly method. Bioengineered skin has the potential immunological advantage of lacking passenger leukocytes including antigen-presenting cells. The skin constructs were transplanted across major histocompatibility complex (MHC) barriers in a porcine animal model. Animals received a second grafting of the same skin construct 7 weeks after the first set of grafts together with MHC-matched constructs to assess for clinical sensitization.
Results: All alloconstructs successfully engrafted with histologic evidence of neovascularization by day 4. Complete cellular rejection and tissue loss occurred by day 8 for most grafts. After the second application, accelerated rejection (<4 days) took place with the development of swine MHC-specific cytotoxic alloantibody.
Conclusions: These data demonstrate preclinically that self-assembled allogeneic constructs engraft and reject similar to allogeneic skin despite the absence of professional donor antigen-presenting cells.