Effect Of Deep Hypothermia Technology On Growth Factor Activity In Skin Tissue

Objective: Compare the rapid freezing method and slow freezing method to the expression of VEGF and TGF-β1 in skin tissue,and explore the effect of comparing different freezing methods on skin tissue activity in deep hypothermia technology.Method: Twenty-five healthy New Zealand white rabbits were randomly divided into blank control group,slow freezing and rewarming group on day 1 and 3 after operation,fast freezing and rewarming group on day 1 and 3 after operation.The blank control group directly took the rabbit’s back skin tissue;the rapid freezing and rewarming group: the skin tissue was soaked in dimethyl methylene maple solution and washed with sterile physiological saline,and then the skin pieces were packed in a sterile double-layer sealed bag and directly injected Preserved in liquid nitrogen;slow freezing rewarming group: immersed in a solution of rabbit’s back skin tissue in dimethyl methylene maple and washed with sterile normal saline,then the skin pieces were packed in a sterile double-layer sealed bag and frozen at 4 ° C After 1 h,freeze at-20 ° C for1 h,and then again at-80 ° C for 1 h,and then programmatically cool it down before putting it into liquid nitrogen;slow freezing rewarming group and fast freezing rewarming group After slow rewarming,the skin was packed and replanted.The skin tissues were collected on the 1st and3 rd day after the skin replantation.The soft tissue of dorsal skin of the five groups of rabbits was collected from the dorsal skin of rabbits to observe the oxygen consumption of isolated skin,and the pathological changes of skin in each group were detected by morphological observation of staining light microscope and immunohistochemical staining.Results:1.Hematoxylin-eosin(HE)staining results: The comparison between the blank control group and the slow frozen rewarming group on the first and third days after operation,and the fast frozen rewarming group on the first and third days after operation,P <0.001,the difference was considered statistically significant,indicating the morphological structure of the skin Both were less regular than the control group.There was a significant difference between the slow frozen rewarming group at 1 and3 days after surgery and the fast frozen rewarming group at 1 and 3 days after surgery(t value was 13.515,P <0.001).It is statistically significant,indicating that after the experimental groups were frozen and stored,the pathological changes of the skin tissue morphology of the slow freezing method were gradually reduced.2.Index results of oxygen consumption in isolated skin:Compared with the(fresh skin)blank control group,the slow frozen rewarming group on the first and third days after surgery was compared with the fast frozen rewarming group on the first and third days after surgery.The oxygen level was higher than that of the rapid freezing and rewarming group,and the skin activity of the slow freezing and rewarming group was higher than that of the fast freezing and rewarming group.The t value was 5.134,P <0.001,and there was a statistical difference.3.Index results of skin tissue immunohistochemistry:1.Plaque-like expression of VEGF was seen in the dermal layer of the skin by two different freezing methods.Compared with the other four groups,the expression of VEGF factor in the blank control group was higher than that of the other four groups,P <0.001,which was statistically different.On the 1st and 3rd day after the slow-freeze rewarming group,compared with the fast-freeze rewarming group on the first and third days after surgery,the expression of VEGF factor in the slow-freeze rewarming group was higher than that of the fast-freeze rewarming group.It was12.890,P <0.001,and the expression of VEGF factor was statistically different.Plaque-like expression of TGF-β1 factor can be seen in thedermal layer of the skin by two different freezing methods.Compared with the other four groups,the expression of TGF-β1 factor is higher in the blank control group than in the other four groups,P <0.001.Statistical differences:2.Compared with the rapid freezing rewarming group on the first and third days after operation,the expression of TGF-β1 in the slow freezing rewarming group was higher than that of the rapid freezing and rewarming group on the first and third days after surgery.In the frozen rewarming group,the t value was 7.307,P <0.001,and the expression of TGF-β1 factor was statistically different.2.Conclusion:1.After freezing and warming the skin tissue,the activities of VEGF(vascular endothelial cell growth factor)and TGF-β1(transforming growth factor β1)are reduced to different degrees;2.Slow frozen rewarming group had less effect on skin tissue than fast frozen rewarming group,and slow frozen rewarming group had less effect on VEGF and TGF-β1 activity.