Experimental Research On The Mechanisms Of Scarless Wound Healing In Fetal Human Skin

Adult skin wounds heal with scar formation, in contrast, early gestation fetalskin wounds(second to early trimester) do not. This important observation has led to a series of studies designed to determine the mechanisms of fetal repair. In this study. we have developed a new model of human fetal skin wound healing. Grafts of human fetal skin placed onto athymic mice subcutaneously retain the morphologic features of normal development. Linear incisions were made in each graft 7 days after transplantation. Complete epidermal and dermal graft wound healing without scar formation was demonstrated histologically. In this model, species-specific immunohistochemistry for TGF- ~, bFGF, PDGF, EGF, CD44, In situ hybridization for PRX-2, HOXBI3, HOX2.2, HOX2.3, flow cytometry for CD44 and measurement of HA were performed, constrast to human adult wounds. Many differences were found between the fetal and the adult contently and locally, so were them after wound. In the conclusion, the intrinsic properties of fetal skin, especially the Homeobox Genes, which are related to the development of fetus, determine whether wounds heal with or without scar.