Objective: To investigate the application of autologous keratinocyte suspension transplantation in skin reconstruction.
Methods: Forty adult Sprague Dawley rats (weighing, 210-230 g) were randomly divided into 4 groups (n=10): high density keratinocyte suspension transplantation (1X106 cells/cm2) group (group A), middle density (1 x 10(5) cells/cm2) group (group B), low density (1 x 10(4) cells/cm2) group (group C), and control group (group D). Skin samples were harvested from the rats in groups A, B, C for the isolation of keratinocytes. The model of anti-contracture of full thickness skin wound was made in rats and autologous keratinocyte suspension was transplanted into the wound. The wound was covered by the allogeneic skin (allogeneic skin derived from Wistar rats). The survival of rats was observed after operation. The survival of allogeneic skin was observed at 7, 14, and 21 days after operation, and wound healing rate was calculated after allogeneic skin dropped off. Histological staining and immunohistochemical staining were carried out at 21 days after operation.
Results: All the rats survived to the end of the experiment. The allograft skins survived in all groups, dried and dropped off. The epithelium sheet could be seen in groups A and B at 21 days, a few very thin epithelium in group C, and no epithelization in group D. The wound healing rate of groups A (62.9% +/- 9.6%) and B (64.2% +/- 9.1%) were significantly higher than that of groups C (38.5% +/- 5.7%) and D (22.7% +/- 5.5%) (P<0.05), and significant difference was found between groups C and D (P<0.05), but there was no significant difference between groups A and B (P>0.05). The results of histological observation showed that squamous epithelial cells were observed in groups A, B, and C, but not in group D; obvious layers of epidermis were observed in groups A and B, thin epidermis and inflammatory cell infiltration in group C, and granulation tissue in group D. The immunohistochemistry staining showed that the expressions of collagen type IV and collagen type VII in groups A, B, and C; the percentage of collagen type IV and collagen type VII positive cells in groups A and B were significantly higher than that of group C (P<0.05), but there was no significant difference between groups A and B (P>0.05). The expressions of collagen type IV and collagen type VII in group D were negative.
Conclusion: The repair of full thickness skin wound with graft of autologous keratinocyte suspension can achieve reconstruction of the skin. The appropriate density of keratinocyte suspension for wound healing is 1 x 10(5) cells/cm2.