[Primary grafting research of tissue engineered oral mucosa lamina propria on skin full thickness wounds].

OBJECTIVE

To study the allograft effect of two kinds of tissue engineered oral mucosa lamina propria on skin full-thickness wounds.

METHODS

The cultured Wistar rat oral mucosa fibroblasts (OMF) were incorporated into collagen or chitosan-collagen to construct the tissue engineered oral mucosa lamina propria, and then the OMFs were labeled with BrdU. The full-thickness round skin defects were made with a round knife (diameter, 0.8 cm) on the backs of 36 Wistar rats (21-25 weeks old), which were divided into 2 experimental groups: the fibroblast-populated collagen lattices (FPCL) group (grafted by FPCLs) and the fibroblast-populated chitosan collagen lattices (FPCCL) group (grafted by FPCCLs), and the control group (only covered with gauges). All the wounds were observed by the naked eyes or the light microscope, and were measured 4, 7, 14, and 21 days postoperatively.

RESULTS

There were no infection during the wound healing period. At 7 days after the grafting, the wounds in the 3 groups were covered by scab and/or gauze; at 14 days, the gauze and scab on the wounds in the three groups were all replaced by the new epidermis naturally except one scab each in the FPCCL group and the control groups, which was replaced at 17 days. All the centers of the new epidermis were measurable as the pink red points. At 21 days, all the new skins were smooth without hairs, and their color was similar to the normal one. At 4, 7, and 14 days, there was an indication that the wound diameters became significantly smaller in the three groups; but after the 14th day, there was no significant indication of this kind. At 7 days, the wound diameter in the FPCL group was significantly smaller than that in the FPCCL group and the control group (P < 0.01). Under the light microscope, at 4 days postoperatively, the decayed tissue on the surfaces of the recipient wounds in the FPCL group and the FPCCL group was separated from the lower granular tissue in which there were many inflammatory cells, fibroblasts, and new vessels. There was a similar phenomenon in the control group. Each skin wound in the three groups was only partly keratinocytes at 7 days postoperatively. The recipient wounds were wholly keratinocytes with when rete ridges observed at 14 and 21 days, but in the control group the wounds were keratinocytes with no rete ridges. Fibers in the new dermis were thin. The OMFs with Brdu appeared in the granular tissue and new dermis at 4, 7, 14, and 21 days postoperatively, which could be illustrated by the immunohistochemical staining. The positive OMFs and the granular tissue joined in the repair of the skin defects without any allergic reaction during the period of the wound healing.

CONCLUSION

The oral mucosa fibroblasts as the new seed cells can join in the repair of the skin defects effectively and feasible. The fibroblast-populated collagen lattices and the fibroblast-populated chitosan collagen lattices can repair skin defects effectively and feasible, too. And the quality of the new skins was better in the two experimental groups than in the control group.