|Objective Preparation of topical VEGF165-insulin composite gel and observe its deep Ⅱ degree burn wound healing role in diabetic rat.
Methods Carbomer with new gel matrix, were added to VEGF165, insulin and they were formulated into gel, becoming VEGF165 gel, VEGF165-insulin composite gel and blank gel. To observe the gel character , detection of pH value. 75 SPF male wistar rats weighing 190 ~ 290g, were randomly divided into normal control group, diabetic control group, insulin gel group, VEGF165 gel group, VEGF165-insulin gel composite, 15 rats in each group. Except the normal control group, other groups of rats fasting 12h after intraperitoneal injection of streptozotocin (55 mg / kg) preparation of type 1 diabetes model, normal control rats injected at the same dose sodium citrate buffer fluid. Type 1 diabetes rats after modeling successfully, using heated water bath 80 ℃, the preparation of deep Ⅱ degree scald model. Normal control group, diabetic group wound external blank gel matrix, the rest of the group of external application of corresponding gel preparation, daily change medicine one times. Deep Ⅱ degree burns after a successful modeling survival of the rats was observed at 3, 7, 11 , 15 ,21d point of wound healing in diabetic rats and calculate the rate of wound healing in each group. In each time point were randomly killed three rats in each group take scalded skin full-thickness specimens for histological and immunohistochemical staining to observe the time of inflammatory cells, angiogenesis and collagen.
Result: Each gel preparation of transparent, moisturizing excellent, good adhesion, easy painting and cleaning, no tissue toxicity. The rats without infection and death. Burn wounds in each group was not reduced obviously after three day, VEGF165-insulin composite gel group the highest rate of wound healing in 7,11,15,21d, diabetic group was the lowest, VEGF165-insulin compound gel group healing rate compared with others group, the difference were statistically significant (P <0.05). Pathological observation showed each time VEGF165-insulin composite gel group formation of granulation tissue and and epithelium were superior to others .Immunohistoch-
emical staining showed that each microvessel quantity and typeⅠcollagen group .Ⅰcollagen expression positive rates start at 3d, and the positive cells was significantly increased with time; each time point VEGF165-insulin composite gel group microvessel density and collagen type Ⅰar...