“Ultraviolet C phototherapy as an adjunct wound therapy in full-thickness wound of a rat model”

Abstract

Ultraviolet C (UVC) phototherapy is a potential modality to improve wound healing due to its well-known antimicrobial properties, and it promotes the expression of certain growth factors. However, limited data exist to show the clinical effect of UVC in wound healing compared with other advanced modern dressings. This animal preclinical study involved 56 Sprague–Dawley female rats aged 3 months old, weighing between 250 and 300 g, which were acclimatized for one week. Following the creation of a 2 × 2-cm-square full-thickness wound over the dorsum of each rat, they were divided into four treatment groups, namely, the control, UVC, hydrofiber silver, and UVC/hydrofiber silver groups. On Days 2, 4, 7, 10, 14, 21, and 28 postwounding, two rats from each group underwent wound assessment via wound measurement (mm2), calculation of the percentage of wound contracture and percentage of epithelization. Wound specimens were obtained for histological examination of inflammatory cells (neutrophils, lymphocytes and macrophages) and fibroblast cell counts. There was a relationship between wound size reduction and time to heal (P<0.05, R2=0.70) among the four treatment groups. The UVC/hydrofiber silver group had a significantly smaller wound size given the time to heal compared with the control group (P = 0.01) and UVC group (P = 0.02). There were no significant differences in terms of wound contracture and epithelization percentage among the four treatment groups. Histopathological examination revealed a significantly lower mean fibroblast count in the UVC/hydrofiber silver group than in the other groups (P = 0.025). These data suggested that UVC phototherapy did not increase the rate of healing but maintained the integrity of the wound by providing antimicrobial properties and preventing overproduction of fibroblasts. UVC was also safe, as no overt inflammatory response was discovered.