Studies On The Changes After Transplantation Of Acellular Dermal Matrix

[Objective] To investigate the changes of allo-ADM and xeno-ADM transplanted underneath the skin and the changes of being combined allo-ADM with thin split-thickness autograft by animal experiment.[Method] Split-thickness allograft and xenograft, 0.3 ~0.5mm thick, were obtained from full thickness skins of SD rat and human with a dermatome. Donor skins were treated with 1 M NaCL, 0.1% glutaraldehyde, 0.5 % SDS and 0.25 % trypsin successively. The resulting acellular dermal matrices were then freeze-dried in a freeze-dryer and hydrated in PBS. The processing technique resulted in acellular dermal matrices (allo-ADM and xeno-ADM), which were transplanted underneath the skin of SD rat. Composite skin (CS), combined allo-ADM with thin split- thickness autograft (0.1 mm thick), was implanted on SD rat's open wound. The dynamic changes were researched for 3~4 months.[Result]1.The processing technique removed all the cellular components from the donor skins and retained basement membrane. Regular orientation and integral framework of collagen bundles and elastin was present in elastic and flexible ADM. The gross and III/I type ratio of collagen was no change after donor skins were treated.2.Transplanted underneath the skin, most of ADM exhibited a good 'take' and were demonstrated host cell (such as fibroblast) infiltration and neovascularization by histological biopsy. ADM syncretized the host tissue and its area was decreased only at 1, 2 months. At 2 weeks, 1 and 2 months, there was respectively one ADM that showed filemot and was separated by host in xeno-ADM group. At 1 month, there was much cellular component and abundant capillary in xeno-ADM. In addition to fibroblast, there were many chronic inflammatory cells, together with increase of AKP activity. The gross of collagen descended and III/I type ratio ascended obviously. Along with time this reaction was disappeared gradually. However, allo-ADM showed angiogenesis at 2 weeks and no obvious change of cellular component, collagen gross and III/I type ratio.Xenograft and xeno-ADM contained abundant elastin. After transplantation of xeno-ADM, the change of elastin was no obvious except decrease at one month. Elastin was scarcely present in allograft and allo-ADM, essentially present around the accessories and disappeared at 4 months.3.Transplanted on the open wound, composite skin, which combined allo-ADM with thin split- thickness autograft, exhibited a high percentage of survival. Histological evaluation of biopsy demonstrated good neovascularization, invasion of host cell (such as fibroblast) and no infiltration of inflammatory cell. Long-term observation showed smooth...