RESUMO
<p><b>OBJECTIVE</b>To study the promotion effect of stromal cell-derived factor 1 (SDF-1) on the migration of epidermal stem cells (ESC) in the healing process of frostbite-wound model ex vivo.</p><p><b>METHODS</b>A three-dimensional model of full-thickness frostbite of skin was constructed (with slot-like wound) out of skin equivalent. The expression of SDF-1 in wound stroma was observed with immunohistochemistry staining on post injury days (PID) 3 and 7. The model frostbite wounds were divided into control group (treated with PBS 50 microL per wound), SDF-1 group (treated with 100 ng/mL SDF-1, 50 microL per wound), and AMD3100 group [treated with 100 ng/mL AMD3100 (50 microL per wound) for 30 minutes, and then SDF-1 50 microL was added per wound]. The redistribution of ESC around wound was observed.</p><p><b>RESULTS</b>The expression of SDF-1 in wound stroma increased gradually on PID 3 and 7. Compared with those in control and AMD3100 groups, there were more ESC and epithelial cell layers, and more integrin beta(1)-positive cells appeared at the basal layer of wound in SDF-1 group, and some of the positive cells migrated upward to epidermis.</p><p><b>CONCLUSIONS</b>SDF-1 contributes to wound repair through promoting ESC to migrate toward and gather around wound edge. This may be one of the mechanisms of ESC participating in wound repair.</p>