Abstract:

BACKGROUND: Presently, studies concerning tissue engineering mainly focus on epidermal stem cells and dermal scaffolds, few report the effects of generation speed and different repairing periods of dermis on neogenesis and reconstruction of epidermis.
OBJECTIVE: To investigate the potential influence of dermis during repairing process on the repair and reconstruction of epithelial tissues and to reveal the possible optimum stage for repair of epithelial tissues.
METHODS: Ten New Zealand rabbits were made into animal models with 3 wounds on each dorsum at 0, 7 and 14 days and were divided into 0, 7 and 14 days groups. Amnion carrier compound-membrane loaded with auto-epithelial cells was embedded into rabbits at 21, 14 and 7 days after model preparation. Samples were harvested 7 days after operation to observe the wound healing by using macroscopic and histological assessment (hematoxylin-eosin staining, Mallory PTAH staining), and type Ⅰ collagen immunohistochemistry observation.
RESULTS AND CONCLUSION: The wound in the 0 day group was closely contacted with surrounding tissues without gaps. However, there was concavity in the 7 days group, and the concavity was great and thick in the 14 days group, with a clear boundary to surrounding tissues. It demonstrated that the repairing effect was superior in the 0 day group to other 2 groups (P < 0.05). Compared with other groups, the positive type Ⅰ collagen stratum reticulare dermidis and papillary layer, composed of fibroblast, blood vessel, and collagen fiber, were obviously in the 0 day group (P < 0.05), with high healing rate (P < 0.05). The differences of promoting action on epithelial tissue regeneration exist in different repairing stages of dermis, late stage of hyperplasia and beginning of reconstruction are the optimal periods for accelerating epidermis regeneration.