OBJECTIVETo lower down the antigenicity of heterogenous swine acellular dermal tissue, and to explore the feasibility of clinical using it as a composite graft for human patients.

METHODSSplit-thickness skin was harvested from healthy swines and then processed by two methods. The swine acellular dermal matrix (sADM) was prepared by removing cells from the skin with trypsin and Triton X-100. Then the cross-linked sADM (sADM(1)) and non-cross-linked sADM (sADM(0)) were embedded subcutaneously in rabbits and also transplanted onto the burn wounds of patients. The histological changes and also transplantation results were observed.

RESULTS(1) In animals with sADM(0) embedded subcutaneously, the grafted tissue was invaded immediately by host cells with obvious inflammatory reaction and tissue degradation. But there was less inflammatory reaction, and with no obvious skin degradation and contraction with sADM(1). (2) In ten burn patients with III degree burn wounds and one patient with wound in chest after scar removal, sADM and ultra-thin skin (UTS) composite graft were grafted on the wounds with autologous thin skin (ATS) and autologous razor-thin or UTS as the control. Nineteen pieces of composite skin of sADM with UTS were grafted on the wounds with survival rate of 78.9%, exhibiting no evident difference with that of ATS. When sADM(0) and UTS were grafed, there exhibited remarkable early inflammatory reaction and wound contraction with similar external appearance with that of UTS. Whereas when sADM(1) and UTS were grafted, there appeared less early inflammatory reaction and wound contraction, resulting in an even appearance and soft to touch similar to that with ATS. But ulceration occurred, with exposure of sADM(1), exposure and severe macrophage reaction to foreign body in 6 wounds of 3 cases 12.8 +/- 6.9 weeks after sADM(1) and UTS grafting.

CONCLUSIONGrafting of sADM as a dermal substitute of composite skin could alleviate early post-grafting immune reaction and improve UTS grafting results. But the delayed graft rejection couldn't be avoided.