Establishment of second-degree burn wound models. Histological analysis showed that injury of burn wound was extended into both epidermis and dermis. In normal skin section, thick squamous epithelium covered the epidermis, and both of epidermis and dermis had the normal structure with several hair follicles and sebaceous glands (a). In burn wound skin section, epidermis and dermis lost their normal structure. Of note, squamous epithelium layer was removed, and epidermis was necrotized. Moreover, the underlying stromal tissue was swollen and congestive (b). These results indicated that the second-degree burn model was successfully established in experimental mice. The arrows indicated the border between the dermis and hypodermis.