| Objective The acellular porcine small intestinal submucosa was used as a dermal support and SD rat autologous blade thickness skin graft to repair the full-thickness skin defect of SD rats.Compared with the pig acellular dermal matrix,the general condition of the wound,the survival rate,the shrinkage rate and histological characteristics were analyzed to provide a theoretical basis for further clinical trials of the acellular porcine small intestinal submucosa..Methods 1 Grouping of experimental animals 36 SD rats were randomly divided into group A(experimental group)and group B(control group)by randomized block method,with 18 rats in each group.Group A was a combination of acellular porcine small intestine mucosa and autologous blade thickness skin graft,and group B was a combination of porcine acellular dermal matrix and autologous blade thickness skin graft.2 Preparation and treatment of full-thickness skin defect model in experimental rats(1)Make a full-thickness skin defect of 2.5*2.5cm on the back avoiding the spine,and take off the skin piece for use.(2)The two sets of dermal scaffold materials were sutured and fixed with the wound surface,and the removed skin pieces were manually trimmed into a thick blade with a scissors,covered on the skin bio-patch,sutured and fixed,and pressure-wrapped.3 At 2 weeks,4 weeks,8 weeks,12 weeks after operation,the general condition of the rats was observed,the wound healing was observed,and the wounds were photographed using Image-J image analysis software to calculate the wound survival rate and wound contraction.The rate was analyzed by using spss19.0 statistical software.4 At the 4th,8th,and 12th week after operation,the animals in each group were sacrificed and grossly dissected.The skin grafted area and surrounding normal tissues were used as specimens,fixed in 4%paraformaldehyde,routine paraffin sections,HE staining,and microscopic observation of pathological changes,including Inflammatory cell infiltration,epithelial cells,fibroblast growth,collagen arrangement,capillary structure and bio-paste degradation.Results 1 General observation The animals in each group had normal feeding and water intake after skin grafting,and they were free from activities and had good mental state.2 Wound condition observation Each time the dressing was changed,the wound surface was observed.It was found that there was no abnormal redness and bleeding and bleeding in the wounds of the two groups,and the dressing was not loose.3 Wound healing(1)Survival of skin grafting area After 2 weeks,the survival rate of the experimental group(96.0±9.6)%was higher than that of the control group(87.8±18.1)%,and the difference was not statistically significant(P>0.05).(2)Contraction of skin grafting area At 4 weeks after operation,the wound shrinkage rate of the experimental group was(26.2±16.1)%lower than that of the control group(28.9±19.5)%,but the difference was not statistically significant(P>0.05).At 8 weeks after operation,the wound contraction rate of the experimental group was(27.5±5.3)%lower than that of the control group(33.3±20.2)%,but the difference was not statistically significant(P>0.05).The wound contraction rate of the experimental group was 12 weeks after surgery(30.3±22.0)%was lower than the control group(40.8±17.6)%,and the difference was statistically significant(p<0.05).4 Histological observation 4 weeks after surgery,the implanted material and the grafted skin of the two groups were well mixed.There were a large number of fibroblasts and new capillary growth in and around the implant material,and there were inflammatory cells.infiltration.At 8 weeks postoperatively,fibroblasts and new capillary capillaries were found in and around the implanted material,and the inflammatory cells were less than 4 weeks after surgery.The original collagen fiber structure of the two groups of implant materials is clear and loose.At 12 weeks after surgery,the implant materials in the two groups were basically replaced by new collagen fibers.The new collagen fibers were arranged in an orderly manner,which was basically parallel to the epidermis and the blood vessels were very rich.Conclusions 1 This experiment demonstrated that there was no significant difference in the survival rate and early wound shrinkage rate between the whole-skin skin defect of the acellular porcine small intestine submucosa combined with the autologous blade thickness skin repair and the pig acellular dermal matrix.2 This experiment demonstrated that the acellular porcine small intestine submucosa combined with autologous blade thick skin repaired the full-thickness skin defect of the rat compared with the pig acellular dermal matrix to improve the scar formation at the later stage of the wound,and the effect was better.3 The decellularized porcine small intestinal submucosa used in this experiment has certain feasibility for further clinical trials.small intestinal submucosa can effectively repair rat skin defects,and it has certain advantages in promoting wound healing and preventing wound contraction compared with porcine acellular dermal matrix. |
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