Figure 1.

(A) Acute and chronic wounds. Acute wound healing is characterized by early re-epithelization, in contrast to chronic wound healing which is characterized by hyperproliferation of inflammatory cells, including macrophages and neutrophils, as well as high numbers of immature and friable microvessels. This environment enables bacterial infiltration and biofilm formation. (B) Development of a chronic wound. Acute wounds are characterized by a breakdown in reactive oxygen species, with the enzymes catalase and glutathione peroxidase having significant functions. Inhibition of these enzymes, using MSA and ATZ, leads to decreased ROS breakdown, resulting in excess ROS, induction of chronicity and excess bacterial load. (C) Study design. Thirty-two db/db mice received intraperitoneal injections of ATZ followed by a full-thickness dorsal skin wound (1 cm²). MSA was applied topically to the wound bed, washed off, and the wounds were covered with occlusive dressing (Chronic diabetic group) or a collagen-glycosaminoglycan implant plus occlusive dressing (Treated chronic diabetic group). Fifteen db/db mice underwent dorsal wounding and were covered with occlusive dressing (Diabetic control group). ATZ, 3-amino-1,2,4-triazole; MSA, mercaptosuccinic acid; ROS, reactive oxygen species.