Construction of diabetic mice model carrying external wound for the evaluation of topical applications on the impaired wound healing

Chronic leg ulcer is one of the diabetic complications causing continuous pain and higher mortality risk. The therapeutic treatment of chronic diabetic wounds can be studied through animal models which simulate the human pathology. Experimental diabetes in mice induced by streptozotocin (STZ) is an easy method with low cost. There have been several studies using STZ for diabetic mice model of cutaneous excisional wound. However, those procedures are different in many factors such as dose of STZ, mouse weight, blood glucose level and the method for assessing health status in mice. We have constructed the criteria to evaluate the health status of the experimental mice including skin color, fur condition, ability to move and body condition. These criteria of health status wereused together with the blood glucose level to evaluate the male mice’s sensitivity to a single high dose (100-150 mg/kg) of STZ. Approximately 40 % of 20–28 g weighted mice, which were injected by 125 mg/kg STZ, developed diabetes in a good health status in the first two weeks after injection. Mice with blood glucose level higher than 200 mg/dL had damaged islet and stably high blood glucose as well as stable health status after two weeks carrying wounds. The wound healing process of the diabetic wounded mice occured relatively slower than that of the control group (non diabetic). The model of diabetic wounded mice has been used to evaluate of the wound healing effect of the rhPDGF-BB protein which has been used in the treatment of chronic wounds caused by human diabetes.