Acute Ultraviolet Radiation Perturbs Epithelialization but not the Biomechanical Strength of Full‐thickness Cutaneous Wounds1. (4th January 2016)

• Record Type: Journal Article
• Authors: Danielsen, Patricia L.; Lerche, Catharina M.; Wulf, Hans Christian; Jorgensen, Lars N.; Liedberg, Ann‐Sofie H.; Hansson, Christer; Ågren, Magnus S.
• Is Part Of: Photochemistry and photobiology. Volume 92:Number 1(2016)
• Page Start: 187
• Page End: 192
• Publication Date: 2016-01-04
• Subjects: Photochemistry -- Periodicals; Light -- Physiological effect -- Periodicals; 541.35
• DOI: 10.1111/php.12552
• Languages: English
• ISSNs: 0031-8655

Abstract

Abstract: We hypothesized that priming of the skin with ultraviolet radiation (UVR) before being injured would enhance wound healing. Four groups, each comprising 20 immunocompetent hairless mice, were exposed to simulated solar irradiation in escalating UVR doses; 0 standard erythema dose (SED) = control, 1 SED, 3 SED and 5 SED. Twenty‐four hours after UV irradiation, inflammation was quantified by skin reflectance (erythema) and myeloperoxidase (MPO) tissue levels, and two 6 mm full‐thickness excisional wounds and one 3 cm incisional wound were inflicted. Epidermal hyperplasia was assessed by quantitative histology. Five days after wounding, wound coverage by neoepithelium and wound width of the excisional wounds was quantified in hematoxylin–eosin sections, and breaking strength was measured in strips from incisional wounds. Erythema ( P < 0.001), MPO levels ( P < 0.0005) and epidermal cell layers ( P < 0.001) increased dose‐dependently by UV exposure of dorsal skin. In the excisional wounds, epithelial coverage decreased ( P = 0.024) by increasing the UVR dose, whereas there was no significant difference ( P = 0.765) in wound MPO levels. Neither wound width ( P = 0.850) nor breaking strength ( P = 0.320) differed among the groups. Solar‐simulated UVR 24 h before wounding impaired epithelialization but was not detrimental for surgical incisional wound healing. Abstract : Ultraviolet radiation (UVR) elicits an inflammatory response in the skin and increases the proliferation of basal cells of the epidermis. The consequences of these effects on wound healing remain unknown and were therefore studied here. We exposed immunocompetent hairless mice for escalating does of solar‐simulated UVR. Twenty‐four hours later full‐thickness wounds were made in the skin and their postoperative healing followed. We found that UVR dose‐dependently impaired epidermal coverage of the wounds (Figure), whereas UVR had no effect on the biomechanical strength of the surgical wounds. Our results ought to be taken into account when planning for surgical procedures in the skin.