RÉSUMÉ
Abstract BACKGROUND: As an emerging technology, tissue-engineered skin has great application prospects. Keratinocyte growth factor (KGF) is proved to promote the proliferation of epidermal cels. OBJECTIVE: To evaluate the effect and characteristics of tissue-engineered skin carrying KGF nanocapsules in repairing skin defects of nude mice. METHODS:(1) The acelular dermal matrix loading KGF (KGF-ADM) was constructed. The human epidermal stem cel population and fibroblasts were captured and cultivated, and then identified. Epidermal stem cels were cultivated on the KGF-ADM and their growth was observed. The tissue-engineered skin loading KGF nanocapsules was transplanted onto the ful-skin defects on the back of nude mice compared with a blank group without keratinocyte growth factor nanocapsules and a control group with skin autograft. In 2, 4 and 6 weeks after transplantation, the contraction and histological healing of the skin were observed respectively. Then anti-human keratin 10-FITC and β1-integrin-Cy3 immunofluorescence were applied to detect the origin, growth and differentiation of stem cels in the epidermis and dermis. RESULTS AND CONCLUSION: The epidermal stem cel population grew wel on the surface of KGF-ADM and attached tightly. There were smal round epidermal stem cels and polygonal terminaly-differentiated cels, which presented with partly cloning growth and a tendency of merging into pieces. The results of tissue-engineered skin with KGF nanocapsules in repairing the skin defects were better than those of the blank group and the control group in 2, 4 and 6 weeks after transplantation. The transplanted skin could fuse with adjacent skin completely, but stil showed some contraction. Under the microscope, they showed good epidermis with layers and normal keratose stratum, and meanwhile, there were stil some β1-integrin+ cels at 8 and 10 weeks, which were epidermal stem cels or transient amplifying cels identified by immunofluorescence. These findings indicate that the tissue-engineered skin carrying KGF nanocapsules has good outcomes in repairing skin defects of nude mice, which is better than common tissue-engineered skin without KGF nanocapsules and autogeneous skin transplantation.