| Background: Photoaging refers to skin aging caused by a variety of exogenous factors,mainly ultraviolet radiation.Photoaging is common and not only can cause a variety of cosmetic problems in the exposed area,but also has a direct or indirect relationship with skin tumors.Nude mice were irradiated with ultraviolet light to induce a local photoaging model.Adipose-derived stem cells are a type of adult mesenchymal stem cells isolated and isolated from adipose tissue.Because of their multiple differentiation,strong in vitro proliferation ability,and abundant sources,they have become the most promising stem cells in the field of plastic surgery.Objective: 1.To establish a photoaging model for nude mouse skin.2.To observe the therapeutic effect of adipose-derived stem cells on skin photoaging in nude mice.3.To explore the mechanism of adipose-derived stem cells in treating skin photoaging.Methods: 1.Sixteen nude mice were randomly divided into a blank group(8)and a model group(8,UVB lamp was irradiated every two days for 8 weeks).The skin macroscopic performance and elasticity of the exposed area were observed,and the blank group was compared.And model group skin histopathological changes and collagen-1 content in the skin.2.Thirty nude mice were randomly divided into five groups,namely the blank control group(6),the model irradiation group(6,UVB irradiation every two days for 8 weeks),and ADSCs after 10 days,30 days,and 60 days.Group(6 animals in each group,UVB was irradiated every two days for 8 weeks,and ADSCs were observed for 10,30 and 60 days after injection).The gross changes and histopathological and immunohistochemical staining changes of the five groups of nude mice were compared,and the changes of the indicators of Collagen-1,MDA,and SOD in the skin tissue were detected by Western blot and Elisa,respectively,and then statistical analysis and comparison were performed.Results: 1.UVB light simulates the typical light such as coarse wrinkles,obvious pigmentation,thickening of the epidermis,infiltration of inflammatory cells,and disordered arrangement of collagen.General changes in aging and histopathological changes;there were no obvious abnormal changes in the blank group.2.Regarding the changes in skin macroscopic appearance and elasticity,compared with the abnormally thickened and thickened skin on the back of the model irradiation group,and the change of color,the skin appearance of nude mice was significantly improved on the 10 th and 30 th days after stem cell injection(reddish color,soft texture),Wrinkles are also relatively reduced;at the same time,skin elasticity is better.3.In the HE tissue staining,Masson staining,and Weigert staining pathological sections of the skin tissue,it can be seen that the abnormally thickened epidermal cells decreased,the collagen content increased,the elastic fibers rearranged and distributed in the early(within 30 days)after stem cell injection,and the inflammatory cell infiltration decreased.But after observing the long-term changes after stem cell injection,various indicators have rebounded.4.In Western blot detection and CD31 immunohistochemical staining,it can be seen that the collagen content and the number of new blood vessels increased early(within 30 days)after stem cell injection.5.Elisa detected the content of MDA and SOD in skin tissues.The former decreased significantly and the latter increased significantly after stem cell injection.This shows that the skin's own aging is slowed down and its self-repair ability is increased.Conclusions: 1.Animal models of skin photoaging were explored and improved.And the UVB lamp simulates natural ultraviolet light.After irradiating the skin of the back of nude mice for 8 weeks every two days,the nude mice photoaging model was successfully modeled.2.Adipose-derived stem cells have a certain effect of alleviating and improving photoaging of the skin of nude mice;and the effect is relatively significant early(within 30 days)after stem cell injection. |
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