[Effect of adipose-derived stem cells on radiation-induced acute skin injury in rats].

OBJECTIVE: To investigate the effect of adipose-derived stem cells (ADSCs) on radiation-induced skin injury in SD rats.
 Methods: Radioactive particles 192Ir were used to irradiate the left medial thigh skin of SD rats, and the irradiation dose was at 90 Gy. Then, the rats were randomly allocated into a control group and a treatment group (each n=9). After the irradiation, the control group was injected with 60 µL PBS and the treatment group was injected with 60 µL ADSCs in irradiated skin. The progress of skin damage and healing was observed and photographed every day. Twenty-eighth days after the irradiation, the irradiated skin tissue was taken from the left thigh, and then fixed with formaldehyde fixative solution. At the same time, the skin tissue of the corresponding part of the normal group (n=9) that was not irradiated was also taken. After sampling, embedding and slicing, immunohistochemical staining was used to compare the levels of α-smooth muscle actin (α-SMA), and HE staining was used to compare pathological features of the skin.
 Results: Radioactive particle 192Ir caused the development of III or IV radioactive skin damage. The score of the treatment group was significantly lower than that of the control group. The wounds of the treatment group were basically healed at 28 days, while the ulcer of the control group was unhealed. So, the healing time was shorter in the treatment group. The expression of α-SMA in the skin of the two groups was increased after the radiotherapy. By analyzing the pathological microstructure image, we found that the thickness of epidermis in the control group was greater than that in the treatment group, while the vascular density in the treatment group was greater than that in the control group (all P<0.05).
 Conclusion: Radioactive particles 192Ir can cause skin damage, while the adipose-derived stem cells might alleviate radiation-induced skin injury and promote ulcer healing by promoting angiogenesis.