Umbilical Cord Mesenchymal Stem Cells In The Treatment Of Burn Wounds

Mesenchymal stem cells stem cells is an important member of the family,exists in many tissues,are multipotent stem cells that have the potential of multi-directional differentiation and can effectively repair damaged tissues and organs,has made some progress in the field of disease research and treatment of multiple systems.Umbilical cord mesenchymal stem cells,because of their low immunogenicity,abundant sources,convenient materials,low pollution rate,and smaller ethical requirements,become a better source of stem cells,and umbilical cord mesenchymal stem cells have stronger self-renewal ability.Burns often cause large area of skin defect,skin barrier function loss,internal environment balance disorder,and wound healing time is long.Large area skin transplantation is needed.However,the skin of the burned patients is limited and take Autologous skin from the body causes second injuries.The patient's prognosis is poor and the functional recovery is bad.Later rehabilitation treatment has increased the psychological burden and economic burden of the patients.T Therefore,accelerating the healing of wounds,recovering the appearance and function of the skin,and reducing the pain of the patients have become the problems to be solved in the burn world.Objective:To study the appropriate scald model and provide a reasonable animal model for scalded animal experiments,the suitable animal model is the basis for animal experiments.To study the therapeutic effect of umbilical cord mesenchymal stem cells(UC-MSCs)on burn wounds and its optimal treatment,and to explore the mechanism of promoting healing.To provide theoretical basis and experimental basis for the clinical treatment of UC-MSCs burn wounds.Method:(1)In order to find the best depth of scald,use nude mice to contact 3S,5S,8s time hot water.After second days of scald,the scald scab was excised and the tissue was made to observe the depth of scald by pathological section.Mice were used to prepare bandaging models,steel circles to fix wounds and prevent shrinkage and healing.After surgical packing,the wounds were bandaged and fixed.Resin bandages and elastic bandages were used to bind and fix wounds in mice.Observe the daily diet water of the mice,the basic life injury,and observe whether the packing excipients fall off.(2)Taking into account the immune rejection of UC-MSCs,nude mice were used as experimental subjects.Burn models of nude mice were established by boiling water scald.The scalded area was 1.5cm round wound.Second days a:fter the burn,the scab was performed,and the five groups were treated in different ways(The first group:normal saline group,second groups:UC-MSCs group,third groups:UC-MSCs+ self microskin group,fourth groups:UC-MSCs+ growth factor group,fifth group:UC-MSCs+ growth factor + autologous microskin group).In order to prevent the wound healing,a suitable size steel ring is used to fix the wound.Each wound was covered by skin allograft after burn surgery packing technology on wound bandaged,use elastic bandage to prevent scratching the dressing off.Nude mice were reared in separate cages.The general signs and wound healing of the animals were observed.The healing quality of the wound was observed by HE staining.The indexes of wound healing quality,such as vascular endothelial growth factor(VEGF),fibroblast growth factor(FGF)and proliferating cell nuclear antigen(PCNA),were detected by immunohistochemistry,Western-blotting and QT-PCR.Observed the quality of wound healing in each group.Result:(1)The results of animal observation and HE staining showed that 3S caused ? degree to shallow ? degree burn,5S could cause deep ? degree burn,8s could cause full-thickness skin burns.The survival condition of the mice fixed with resin bandage was poor.Because the bandage is inelastic,it restricts the diet and drinking water of the mice,the animal is thin,and it is easy to die,and it is difficult to bind and remove the bandage.The elastic bandage is soft,the mice are good in activity,able to eat and drink well,live well,and bandage and remove bandages are easier.(2)The transplantation of UC-MSCs to burn wound can promote the healing of burn wound,shorten the healing time and improve the healing quality of the wound.The healing effect of UC-MSCs combined growth factor or autologous particle skin wound healing was better than that of UC-MSCs alone.UC-MSCs,growth factor and autograft mixed transplantation in bum wound,the wound healing time was significantly shorter than the first four group,expression of VEGF,PCNA,FGF is the highest,the better to promote angiogenesis,fibroblast proliferation and cell proliferation,make better wound healing.Conclusion:(1)Boiling water 8S can cause deep III degree scald,the area of scald and the depth of scald are relatively stable,and the difference is reduced.Two kinds of bandage can be fixed to prevent scratching the back of mice accessories fall off,but the better effect of elastic bandage group,animal damage smaller and more convenient,and the preparation method of scald model dressing methods applicable to all kinds of small animal such as rats,mice,nude mice and other animals,can be widely used.(2)umbilical cord mesenchymal stem cells can promote the healing of burn wounds by promoting angiogenesis,cell proliferation and fibroblast proliferation.