Effect of cold atmospheric plasma/NO gas application with different exposure times on healing in wounds with tissue loss in diabetic rats

Applications of cold atmospheric plasma/nitric oxide (CAP/NO) gas have recently garnered popularity when treating impaired wound healing in patients with diabetes. In this study, we aimed to investigate the effects of NO gas application for 60 and 120 s on wound healing in diabetic rats. A dorsal excision 3 cm in diameter was performed in 15 diabetic rats; these rats were categorized into the following 3 groups: DC (untreated diabetic control); DNO/60 (exposure to 200 ppm NO gas for 60 s/day); and DNO/120 (exposure to 200 ppm NO gas for 120 s/day). Wound contraction on days 0, 3, 7, 11, and 14 and wound contraction rate between days 0 and 14 were evaluated. On day 14, tissue samples were collected for histopathologic assessment of inflammation, epithelial regeneration, angiogenesis congestion, and collagen fiber organization. Normality of distribution was assessed using the Shapiro-Wilk test, and intergroup comparisons were performed using the Mann-Whitney U test (NPar Test) and the Kruskal-Wallis test (non-parametric ANOVA). Wound contraction during treatment days 7-14 was significantly greater in the NO-treatment groups than in the DC group (p<0.05). The NO60 s and NO120 s groups showed a significantly higher wound contraction rate than the DC group (p=0.033, p=0.049, respectively). Significant differences were noted between the control and NO groups in terms of inflammation (p<0.05) and between the control group and DNO/60 and DNO/120 groups in terms of collagen organization (p<0.05, p<0.01, respectively). Evaluation of epithelialization revealed significant intergroup differences between the control and NO treatment groups (p<0.01). In this study, the application of NO once a day for 60 seconds and 120 seconds in diabetic wounds contributed equally to wound healing.