Preparation of an acellular dermal matrix using the freeze-thawing technique with and without gamma irradiation

ABSTRACT

An acellular dermal matrix [ADM] is a dermal substitute in which the skin is treated to remove epithelial and dermal cellular components. To compare the histological and immunohistochemical structures of ADMs prepared using the freeze-thawing technique with or without gamma irradiation. Twenty-one human skin specimens were used and divided into three equal groups group I [control group], group II, in which skin specimens were subjected to three repeated freeze-thawing cycles, and group III, in which skin specimens were subjected to three repeated freeze-thawing cycles and subsequent exposure to 5000 rad gamma irradiation. Skin specimens from the previous groups were examined histologically and immunohistochemically for laminin. A morphometric study was carried out for the determination of the number of cells per high-power field [hpf] in both the papillary and the reticular dermis. Both methods of ADM preparation resulted in extensive extraction of cellular components with preservation of the basic dermal architecture as there was a highly significant decrease in the number of cells/hpf in both layers of the dermis in groups II and III as compared with the control group [P<0.001]. However, there was further decellularization in group III as there was a highly significant decrease in the number of cells/ hpf in both the papillary and the reticular dermis in group III as compared with group II [P<0.001]. Immunohistochemical stain of laminin revealed preservation of the epidermal basement membrane in groups II and III. A combination of irradiation and a freeze-thawing technique is recommended in the preparation of ADM for efficient decellularization