Comparison studies of the in vivo treatment of full‐thickness excisional wounds and burns by an artificial bilayer dermal equivalent and J‐1 acellular dermal matrix

The effects upon skin repair were compared between a homemade bilayer dermal equivalent (BDE), composed of a collagen/chitosan porous scaffold and a silicone membrane, and J‐1 acellular dermal matrix (ADM), a commercial ADM that is used widely in China to treat various skin defects. Full‐thickness excisional and burn wounds were prepared on the backs of pigs and then treated with the BDE and J‐1 ADM. Biopsy specimens were harvested on days 7, 14, and 21 after surgery for gross, biochemical, and molecular examinations. In comparison with the burn wounds, the excisional wounds showed accelerated granular tissue formation and superior integration with the equivalents, regardless of their type. Immunohistochemical, immunofluorescence, real time quantitative polymerase chain reaction and Western blotting analyses showed that the vascularization rates in the excisional wounds group were also significantly faster than those of the burn group for both dermal equivalents. There was no significant difference between J‐1 ADM and BDE treatment on the formation of newly formed blood vessels for the excisional wounds at days 7, 14, and 21. However, there was a significant difference in the number of nascent blood vessels formed in the burn wounds after treatment with J‐1 ADM compared with BDE. The highest numbers of newly formed and mature blood vessels were present in the J‐1 ADM‐treated excisional wounds after 21 days. Ultrathin skin grafts were further transplanted on to the regenerated dermis for 28 days, resulting in the repair of the full‐thickness wounds and production of a structure similar to normal skin.