A Protocol for Constructing a Rat Wound Model of Type 1 Diabetes.

A single high dose of streptozotocin injection followed by full-thickness skin excision on the dorsum of rats is a common method for constructing animal models of type 1 diabetic wounds. However, improper manipulation can lead to model instability and high mortality in rats. Unfortunately, there are few existing guidelines on type 1 diabetic wound modeling, and they lack detail and do not present specific reference strategies. Therefore, this protocol details the complete procedure for constructing a type 1 diabetic wound model and analyzes the progression and angiogenic characteristics of the diabetic wounds. Type 1 diabetic wound modeling involves the following steps: preparation of the streptozotocin injection, induction of type 1 diabetes mellitus, and construction of the wound model. The wound area was measured on day 7 and day 14 after wounding, and the skin tissues of the rats were extracted for histopathological and immunofluorescence analysis. The results revealed that type 1 diabetes mellitus induced by 55 mg/kg streptozotocin was associated with lower mortality and a high success rate. The blood glucose levels were relatively stable after 5 weeks of induction. The diabetic wound healing rate was significantly lower than that of normal wounds on day 7 and day 14 (p < 0.05), but both could reach more than 90% on day 14. Compared with the normal group, the epidermal layer closure of diabetic wounds on day 14 was incomplete and had delayed re-epithelialization and significantly lower angiogenesis (p < 0.01). The type 1 diabetic wound model constructed based on this protocol has the characteristics of chronic wound healing, including poor closure, delayed re-epithelialization, and decreased angiogenesis compared to normal rat wounds.