Differentiation of tissue-engineered skin reconstructed with ES cell-derived epidermal stem cells and dermal analogs in vivo

Objective To explore the differentiation potency of tissue-engineered skin reconstructed with ES cell-derived epidermal stem cells and dermal analogs in vivo. Methods The dermal scaffolds were reconstructed by gel-gelatin sponge compounded with mice fetus skin fibroblasts or rat bone BMSCs (tissue-engineered skin Ⅰ,Ⅱ). First, the scaffolds were transplanted into mice full thickness skin defects. And then, ES cell-derived epidermal stem cells, labeled with Hoechst 33342, carried by a layer of biomembrane, were transplanted onto the dermal scaffolds. The differentiation tissue of the tissue-engineered skin was sampled each week. The sections were observed with HE staining, immunohistochemical and dilabeled immunofluorescence methods to test β1 integrin, CK15, CK19, CK10 and CEA. Results The full thickness skin defects, covered with the two types of tissue-engineered skin, were healed at 3-4 weeks. The newborn skin was thicker than normal skin. There were short bulky cellular poles towards dermis. The cells labeled by Hoechst 33342 located in the epidermis expressed β1 integrin, CK15 and CK19. And the tubular or follicular structure in dermis showed nucleus fluorescence and CEA positive. The basal cells of keratinized stratified squamous epithelium expressed CK19 and CK10 positive respectively. There were sebaceous glands-like and hair follicles-like structures in newborn skin. Conclusion The two types of tissue-engineered skin reconstructed with ES cell-derived epidermal stem cells and dermal analogs can restore the skin defects and have the potency to differentiate into sweat glands-like, sebaceous glands-like and hair follicles-like structures in vivo.