ABSTRACT
BACKGROUND:Currently,a variety of mesenchymal stem cells have been confirmed to have the effect of promoting wound repair,but there is still a lack of relevant research on whether placenta-derived mesenchymal stem cells can promote acute skin wound healing. OBJECTIVE:To investigate the effect of placenta-derived mesenchymal stem cell transplantation on the healing of acute skin wound in rats. METHODS:Twenty SD rats were divided into PBS group and stem cell group by the random number table method,with 10 rats in each group.All rats were selected to establish a full-thickness skin defect model.In the PBS group and stem cell group,PBS buffer and placenta-derived mesenchymal stem cells were immediately injected on the wound surface and wound margin immediately and on day 8 after modeling.The wound healing was observed immediately and on days 2,4,6,8,10,12,and 14 after modeling.The skin tissue of the wound surface was taken on day 14 and treated with hematoxylin-eosin staining,Masson staining,immunohistochemical staining and immunofluorescence staining. RESULTS AND CONCLUSION:(1)The wound surface of the rats in each group decreased with the prolongation of treatment time.The wound healing rate and wound epithelization rate of the stem cell group at 14 days were higher than those of the PBS group(P<0.01),and the wound contracture rate was lower than that of the PBS group(P<0.01).(2)The results of hematoxylin-eosin staining showed that the skin wound healing of the stem cell group was better than that of the PBS group;the degree of wound epithelization was higher,and the morphology of collagen fibers was close to that of normal skin.(3)Masson staining results showed that compared with the PBS group,collagen fibers in the skin wound tissue of the stem cell group were significantly increased and thicker,and the content of collagen fibers in the new tissue was significantly higher than that of the PBS group(P<0.01).(4)Immunohistochemical staining showed that the number of new capillaries in the stem cell group was higher than that in the PBS group(P<0.01),while the expressions of tumor necrosis factor-α and interleukin-6 were lower than those in the PBS group(P<0.01).(5)Immunofluorescence staining showed that the number of M2 macrophages in the new wounds of the stem cell group was higher than that of the PBS group(P<0.01),while the number of M1 macrophages was less than that in the PBS group(P<0.01).These findings indicate that placenta-derived mesenchymal stem cells can accelerate skin wound healing,promote wound epithelization,and reduce wound contracture,which may be related to the promotion of capillary angiogenesis,regulation of collagen fiber production,inhibition of inflammation,and regulation of macrophage polarization to M2 type.