| Objective: In recent years,the incidence of diabetes mellitus has increased year by year with the improvement of living conditions and change of diet structure.Diabetic foot ulcer is one of the common diabetic complications,and the amputation caused by diabetic foot is 15 times more than that of non-diabetic patients,and more than 85% of the amputees originate from the worsening of diabetic foot ulcer,and there is a lack of effective clinical treatment for diabetic foot ulcer.Collagenase ointment is mostly used clinically for enzymatic debridement of burn wounds.In this study,we observed the effect of collagenase ointment on the healing of diabetic rat skin ulcer wounds by establishing a deficient skin ulcer model,and tentatively explored the possible mechanism of action.Research methods:1.Model establishment: After SD rats were fed with high sugar and high fat diet for4 weeks,streptozotocin(STZ)was injected intraperitoneally to establish a diabetic(Diabetes Mellitus,DM)rat model,on the basis of which a defective skin ulcer wound was created on the lower limb of DM rats near the joint,i.e.,the defective skin ulcer model of diabetic rats.2.Grouping and drug administration: except for the normal control group(N-con group);the rats with diabetic defective skin ulcer were randomly divided into model group(M-con group),positive drug group(M-coh group,Comwell-Hydrogel dressing),collagenase ointment treatment group A(M-col A group),collagenase ointment treatment group B(M-col B group),and the trauma was exposed for 4 days,and then continuous drug administration was started until the naked eye Basic healing of the trauma could be seen.3.Index detection:(1)Monitor the changes of blood glucose in diabetic rats weekly after drug administration.(2)Wound healing was observed visually and photographed for each group of rats(once a day for the first week and once every other day thereafter),and the wound area was measured using Image J software to calculate the wound healing area and healing rate at each time point.(3)Blood was collected from the orbit of each rat on days 3,7 and 14 after administration,added to an anticoagulation tube,centrifuged,and the upper layer was frozen at-80℃,after which interleukin-6(IL-6),interleukin-8(IL-8)and tumor necrosis factor-α(Tumor necrosis factor-α)were measured using ELISA kits.(TNF-α)levels.(4)Partial wounds of rats in the model group and each dosing group were taken on days 3,7 and 14,respectively,and tissue sections were fixed in paraformaldehyde and embedded in paraffin,and the morphological changes of the wounds were observed by HE staining and Masson staining.-Immunohistochemistry was performed to detect the protein expression of Tumor necrosis factor stimulated gene-6(TSG-6);immunohistochemistry was performed to detect traumatic epidermal growth factor(EGF),and basic fibroblast factor(b FGF),vasculoendothelial growth factor(VEGF);CD31 antibody was used as a marker of microvessels to assess the microvessel density(MVD)of traumatic surfaces.Results:1.After 4 weeks of high glucose and high fat diet,rats were injected intraperitoneally with streptozotocin(STZ)(30 mg/kg),and the blood glucose values were measured by tail clipping at 3d,5d,and 7d,respectively,and the rats were randomized to have blood glucose≥ 16.7 mmol/L.The diabetic rat model was successfully established,and then the diabetic rat model of deficient skin ulcer was surgically produced,and during the administration of the treatment,the diabetic rats were monitored for blood glucose consistently greater than the blood glucose of diabetic rats was continuously monitored at 16.7 mmol/L during the administration of the drug,and no significant difference was found between the drug treatment groups.2.The healing area and healing rate were calculated by monitoring the size of skin ulcers at different time points after drug administration.The results showed that compared with the model group,the healing area of collagenase ointment increased significantly(P< 0.05)on days 4 to 7 and the healing rate increased significantly(P < 0.05)on days 3 to10.The collagenase ointment accelerated the healing of skin ulcer wounds in diabetic rats,and the collagenase ointment treatment was better in the 1 day twice group than in the 1day once group,and the treatment effect was better than that of the positive drug group.3.The histomorphological examination of the skin ulcer wound showed that on the7 th day of administration,the skin structure of the wound was close to normal,the epidermal cells were basically aligned,the granular layer was visible,the dermis and skin accessories were clearly structured,and the collagen fibers were aligned neatly.4.On the 7th day of administration,collagenase ointment reduced the plasma levels of IL-6,IL-8 and TNF-α in rats with diabetic defective skin ulcers(P < 0.05);the aggregation of macrophages on ulcer wounds was significantly reduced in the collagenase ointment treatment group(P < 0.05);the expression of anti-inflammatory factor TSG-6 in the wounds of the collagenase ointment treatment group was significantly increased(P <0.05);collagenase ointment The effect of collagenase ointment treatment 1 day 2 times group was better than collagenase 1 day 1 times group and better than positive drug group.5.Collagenase ointment promoted EGF,b FGF and VEGF expression and increased microvessel density(MVD)in rat ulcer wound tissue.On the 7th day of treatment,EGF,b FGF and VEGF expression and MVD were significantly increased in the wound tissue(P< 0.05),and the collagenase ointment treatment 1 day 2 times group was better than the 1day 1 times group and better than the positive drug group.Conclusion: Collagenase ointment can reduce the plasma levels of IL-6,IL-8 and TNF-α,reduce the aggregation of traumatic macrophages,increase the expression of traumatic anti-inflammatory factor TSG-6,thus inhibiting the inflammatory response,and promote the expression of EGF,b FGF and VEGF and increase the MVD of diabetic skin ulcer wounds,thus accelerating the re-epithelialization of traumatic tissue,granulation tissue growth and vascular This accelerated the healing of diabetic skin ulcer wounds.Collagenase ointment was more effective than the positive drug(Comwell-Hydrogel Dressing),and collagenase ointment applied twice a day was more effective than collagenase ointment applied once a day. |
PDF Full Text Request