OBJECTIVETo assess the feasibility of a polymer material-expanded polytetrafluoroethylene (ePTFE) as wound covering.

METHODSForty-five Sprague Dawley (SD) rats inflicted with open wound on the back were divided into 3 groups, each group 15 rats. Wounds in the autograft group were covered with autologous skin. Wounds in the allograft group were covered with skin from 15 Wistar rats (donor). Wounds in the experiment group were covered with ePTFE. Wound healing in each group was observed with naked eye. Tissue specimens collected on 3rd, 7th, and 14th post-operative day (POD) respectively were stained with HE and examined under light microscope. Macrophages, lymphocytes and fibroblasts were quantified. IL-2 and IFN-gamma levels in the infiltrating mononuclear cells were assessed by immunohistochemistry with expression of gray value.

RESULTSWounds in rats of autograft group and experiment group healed well without redness, swelling or infection. Rejection was evident in the allograft group rats on 8th POD, including epidermis degeneration and focal necrosis in different degree, plus red swelling on wound edge. The numbers of macrophages, fibroblasts, lymphocytes in allograft group were significantly higher than those in autograft group and experiment group (P < 0.01). The average gray values of IL-2 and IFN-gamma of allograft group on 7th POD were 129 +/- 7 and 113.7 +/- 2.7, which were significantly lower than those in the experiment group (144 +/- 8, 137.3 +/- 1.9, respectively, P < 0.01) and allograft group (189 +/- 6, 180.3 +/- 3.7, respectively, P < 0.01).

CONCLUSIONSePTFE will induce minimal inflammatory response and foreign body reaction. It is unlikely to cause side effect when applied to wound surface for a prolonged period. Thus, it is suitable to use ePTFE as wound surface covering.