Study On Transplantation Of Constructed Artificial Composite Skin In Vitro

【Objective】 To establish a composite skin with combining cultured keratinocytes, acellular pig dermis and fibroblasts transfected with PDGF gene in vitro and to observe the healing effects by transplanting the composite skin to the wounds of rat back. 【Methods】 Three types of composite skins were reconstructed by using cultured keratinocytes(CK), acellular xenodermis(AX) and the fibroblasts(Fb) with PDGF gene(PFb): Type A (CK+AX), type B (CK+AX+Fb) and type C (CK+AX+PFb). The growth states of keratinocytes and fibroblasts were observed under phase contrast microscope. The composite skins were detected by histological examination (HE staining). Three types of composite skins which were considered as three groups of A, B and C were transplanted to the wounds on rat back. The wounds of group A, B and C were compared with the wounds transplanted with cultured keratinocyte membrane (group D) and the wounds covered with Vaseline (group E) in skin takes, contraction of the wounds and the vescularization in acellular pig dermis after transplantation.【Results】 More than four-layer keratinocytes, the basement membrane and slight keratinization were observed after histological HE staining. The skin take rates of group B and group C in 2 weeks after skin grafting were much higher that those in any other groups. In 6 weeks the healed wounds in group C were smooth, elastic and wearable. The wound contraction rates in group D and group E were most obvious comparing with any other groups(P﹤0.05). The take rates had significant differences between group C and group D, and had no difference among other groups. In 2～4 weeks after skin grafting the vescularization rate in group C was higher than that of group B and group A(P﹤0.05). The vescularization rates in all groups had no significant differences in 6 weeks(P﹥0.05). 【Conclusions】 The composite skins are constructed with cultured keratinocytes and fibroblasts with PDGF gene on acellular xenodermis. It is concluded that the composite skins we had established have good structure and function and play an important role in wound healing.