The effect of short duration of electrical stimulation on wound healing in acute wound in a rat model

Prolonged application of electrical stimulation (ES) will cause skin discomfort and burns, and therefore may be harmful in the elderly population with morbid conditions. Therefore, it is needed to apply ES in a short duration. However, currently, no studies have been conducted that investigated the effect of short duration of ES on wound healing. This study purpose was to investigate the effect of short duration of ES on wound healing of acute wounds in rats. In this study, a wound was created on the back of rats. Rats were assigned to one of the following 4 groups; ES treatment 5 minutes (5-min group), ES treatment 10 minutes group (10-min group), ES treatment 15 minutes (15-min group), and a control group (film dressing). ES (20 Hz, 320 μs, 50 μA) was delivered for 11 days. From day 4 onward, wound sizes were significantly lower in the 10-min group when compared to the 15-min group, and control group on day 10 and 11. In the 10-min group, inflammation was the lowest when compared to other groups, while the intensity of fibroblast was significantly higher than in the 15-min and control groups. Reepithelialization was most advanced in the 10-min group compared with other groups. The number of MMP-9 positive cells was not significantly different among groups, whereas the number of VEGF-positive cells was significantly higher in the 10-min group when compared with other groups. ES application for 10 minutes significantly reduced inflammation, improved reepithelialization and angiogenesis when compared to shorter and longer applications. ES for 10 minutes also significantly improved wound healing when compared to the use of modern dressing alone. Therefore, it is recommended to apply ES for 10 minutes a day to improve wound healing.