Study on the mechanism of microporous sheep ADM combined with hUCMSC in promoting wound healing

Abstract

Objective: To explore the therapeutic mechanism of microporous sheep acellular dermal matrix (ADM) combined with human umbilical cord mesenchymal stem cell (hUCMSC) to promote the healing of full-thickness skin defect.

Methods: hUCMSC was co-cultured on microporous sheep ADM to form composite biological dressings. Seventy-two nude mice were selected to make full-thickness skin injury models and randomly divided into 3 groups (hUCMSC + microporous sheep ADM group, sheep ADM group and iodophor gauze group), with 24 mice in each group. The wound healing rate of each group was detected at 14 d, 21 d and 28 d after operation, qRT-PCR technique was used to detect the expression of Bax and Bcl-2 in the wound tissues, and the immunohistochemical staining technique was used to detect the expression of Collagen I and vascular endothelial growth factor (VEGF). Data were analyzed with one-way ANOVA and t test.

Results: At 14 d after operation, the wound healing rate of the hUCMSC + microporous sheep ADM group was (65.34 ± 14.72)%, which was significantly higher than that of the iodophor gauze group [(37.54 ± 10.21)%], and higher than that of the sheep ADM group [(49.08 ± 11.16)%], the differences were statistically significant (t = 19.52, 14.72; p < .05). With the gradual healing of the wound, at 28 d after operation, the wound healing rate of the hUCMSC + microporous sheep ADM group was (98.63 ± 15.41)%, which was significantly higher than that of the iodophor gauze group [(81.74 ± 16.27)%], and higher than that of the sheep ADM group [(63.47 ± 14.80)%], the differences were statistically significant (t = -16.42, 20.35; p < .05). The expression of Bax in the wound tissues of the hUCMSC + microporous sheep ADM group was significantly reduced, especially at 21 d after operation, the expression level was 0.25 ± 0.06, which was significantly lower than the iodophor gauze group (0.53 ± 0.16) and the sheep ADM group (0.41 ± 0.12), the differences were statistically significant (t = 3.52, -2.83; p < .05). The expression of Bcl-2 in the wound tissues of the hUCMSC + microporous sheep ADM group was significantly higher than those of the other two groups, especially at 21 d after operation, the expression level was 0.63 ± 0.19, which was significantly higher than the iodophor gauze group (0.34 ± 0.09) and the sheep ADM group (0.46 ± 0.13), the differences were statistically significant (t = 5.31, -6.07; p < .05). Immunohistochemical detection showed that the expression of Collagen I and VEGF in the hUCMSC + microporous sheep ADM group was slightly more than that of the sheep ADM group and the iodophor gauze group, but the effect was not remarkable.

Conclusions: hUCMSC + microporous sheep ADM composite dressing can promote the healing of the full-thickness skin injury and reduce the production of apoptotic cells by carrying hUCMSC.