[A comparative study on immunocompatibility and histological turnover after fresh or preserved human amniotic...

To investigate the immunoreaction, histological reaction and turnover by comparing the xenotransplantation of fresh human amniotic membrane (HAM) with that of preserved HAM, and to analyze the clinical application value of different kinds of HAM preparations.

Subcutaneous implant models were established in 150 BALB/C mice, which were randomized into 5 groups of 30 mice each, based on different implants: fresh amniotic membrane (FAM), double fresh amniotic membrane (DFAM), glycerin preserved amniotic membrane (GPAM), chorion (positive control) or merely operation (negative control). The tissue samples from grafted area were observed with SABC and HE staining, and the inflammatory cells were calculated with light microscopy. 1, 2, 4, 8 and 12 weeks after surgery.

The mice in all of groups were normal in eating and moving, and the wound surface healed well. In all of AM groups, the expression of MHC II and the calculation of inflammatory cells were much less than those in chorion groups, showing significant differences (P < 0.01). At 1, 8 and 12 weeks after surgery, there were no significant differences in the expression of MHC II and the calculation of inflammatory cells in all of AM groups, compared with other groups (P > 0.05). From 2 weeks to 4 weeks after surgery, there were no significant differences in the expression of MHC II and the calculation of inflammatory cells between FAM and DFAM groups (P > 0.05), but they were both more than those in GPAM groups, showing significant differences (P < 0.05). At the 4th week after surgery, in all of AM groups, the expression of MHC II and the calculation of inflammatory cells were less than those at the 2nd week, showing significant difference (P < 0.01). The amniotic epithelium was still alive in fresh AM groups until 4 weeks after transplantation. Early after surgery, fibroblasts infiltrated AM from the substantia basilaris layer while made fibrous capsule around the epithelium. After 12 weeks, the amnion absorbed.

As a kind of heterologous biomaterial, whether fresh or preserved, HAM can be seemed of ideal immunocompatibility and histocompatibility. Fresh HAM with alive epithelium may be more successful in area of repair and reconstruction.