Effects of Carbon Arc Lamp Irradiation on Wound Healing in a Rat Cutaneous Full-Thickness Wound Model

Objective: The objective of the present study was to investigate the application of a carbon arc lamp on wound healing in a rat cutaneous full-thickness wound model. Background data: In clinical practice, wound healing has been promoted by irradiation with a carbon arc lamp. However, the corresponding mechanism has not been clearly defined. Methods: A cutaneous full-thickness wound on the back of rats was irradiated using a carbon arc lamp at a wavelength peak range of 620-740nm with 54 J/cm(2). Injured sham-irradiated control rats were used as the control. The rats were euthanized after 7, 14, and 21 days, while wound reepithelialization and healing quality were examined by histological analyses with comparison between groups. Cell proliferation was observed by 5-bromo-2'-deoxyuridine (BrdU) immunohistochemical staining. Results: Irradiation by the carbon arc lamp significantly accelerated wound healing. The wound-healing rate in the treated group at day 21 was 98.42% +/- 0.56%, compared with 93.58% +/- 1.26% in the control group (p < 0.05). Significant increases in the length of epithelial edges, collagen content, and microvessel density were observed in the wound sites in the treated group at days 7, 14, and 21 (p < 0.05). Moreover, the number of BrdU-labeled cells increased in the wound edge at days 7 and 14 due to irradiation (p < 0.05). Conclusions: The results demonstrated that the carbon arc lamp can promote wound healing together with improvement in its quality by stimulating cell proliferation.