The Effect Of ADSCs Pretreated With SDF-1 On The Wound Healing Of Deep Ⅱ Degree Skin Scald In Miniature Pigs

Skin scald is a common clinical surgical disease with great difficulty in treatment.After scalding,the defense function of the body’s skin is impaired,and a large amount of necrotic tissue appears on the scalded wound surface accompanied by inflammation.If not controlled in a timely manner,it may lead to a decline in the body’s immunity,leading to complications such as infection,sepsis,and even death.Adipose-derived stem cells(ADSCs)are a variety of mesenchymal stem cells(MSCs)that are abundant in source and easy to obtain.Many studies have shown that ADSCs have strong potential application value in promoting the repair of skin injury,but the research on the effect of ADSCs on the healing of scalded wound is insufficient.There is little research in animal skin scald models with better homology with humans,such as monkeys and pigs.Therefore,in this experiment,miniature pigs were selected as experimental animals to establish an model of using ADSCs to intervene in deep II degree skin scald.And we selected stromal cell-derived factor-1(SDF-1)to pretreat ADSCs to further explore the effect of SDF-1 pretreated ADSCs on scald wound healing.In this experiment,the optimal concentration of SDF-1 was determined by CCK-8 method,and the paracrine effect of SDF-1 pretreatment on ADSCs was detected by ELISA.method.Then nine miniature pigs were randomly divided into three groups:scald model group(SM group),adipose-derived stem cells group(ADSCs group)and SDF-1 pretreated adipose-derived stem cells group(SDF-1/ADSCs group).A deep II degree scald model on the back skin of miniature pigs with a circular scald of 3.5 cm in diameter was established.SM group injected2m L PBS subcutaneously at 4 points on the scalded wound,and ADSCs group injected 2m L PBS cell suspension containing 5×10~5 ADSCs,SDF-1/ADSCs group injected 2m L PBS cell suspension containing 5×10~5 ADSCs which pretreated with SDF-1.Clinical observations were conducted on the general condition and local scalded wounds of miniature pigs before and on7th,14th,21th and 28th.Blood samples and skin tissue samples from the scalded area were collected for indicator testing.HE staining and Masson staining were used to observe pathological changes in the skin tissue,blood routine testing related inflammatory cell changes,serum biochemical testing related protein changes,and kit method was used to detect changes in oxidative stress,inflammatory reactions,and tissue regeneration related indicators.The results of this experiment are as follows:(1)The optimal concentration of ADSCs pretreated with SDF-1 is 200ng/m L,and the pretreatment of ADSCs with SDF-1 extremely significant promoted ADSCs to secrete paracrine factors such as VEGF,HGF and IGF.(2)Clinical observation of local scalded wounds showed that compared with SM group,intervention in the ADSCs group and the SDF-1/ADSCs group could reduce wound redness and fluid exudation and accelerate wound healing.(3)Compared with SM group,HE staining results showed that ADSCs group and SDF-1/ADSCs group significantly reduced inflammatory cell infiltration,and the rate of epidermal neogenesis increased.Masson staining results showed that intervention in the SDF-1/ADSCs and ADSCs group could promote the formation of new collagen fibers in the skin.(4)The results of oxidative stress indicators showed that compared with SM group,the ADSCs group and SDF-1/ADSCs group extremely significant increased SOD and GSH contents,while extremely significant decreased MDA contents;Compared with ADSCs group,the SOD and GSH in the SDF-1/ADSCs group were significantly higher than those in the ADSCs group,while the MDA was significantly lower than those in the ADSCs group.(5)The results of inflammation indicators showed that compared with SM group,the ADSCs group and SDF-1/ADSCs group extremely significant reduced TNF-α,IL-1β,CRP,WBC,LYM and NEU contents,while extremely significant increased IL-10 contents,and significantly increased GLB and ALB contents;Compared with ADSCs group,the TNF-α,IL-1βand CRP in the SDF-1/ADSCs group were significantly lower than those in the ADSCs group,while the IL-10 was significantly higher than those in the ADSCs group.(6)The results of regeneration indicators showed that compared with SM group,the ADSCs group and SDF-1/ADSCs group extremely significant increased VEGF,b FGF and TGF-βcontents,and the SDF-1/ADSCs group was significantly higher than in ADSCs group.In summary,ADSCs and SDF-1/ADSCs intervention can promote the wound healing of the deep II degree scald model of miniature pigs skin,improve the microscopic pathological damage of the scalded skin tissue,reduce the inflammatory and oxidative stress reactions of the scalded skin tissue,enhance the regeneration ability of the skin tissue.In this experiment,SDF-1/ADSCs were successfully used to intervene in a deepⅡdegree skin scald model in miniature pigs,demonstrating that SDF-1 pretreatment of ADSCs can promote their proliferative activity and paracrine ability,thereby promote the effect of ADSCs on scald wound healing.This experiment provides a certain experimental basis and theoretical support for the optimization of clinical stem cell therapy for skin scald wound healing.