[ODP5E] e. Others

[ODP-112] Interfering effect of wound exudates on 222 nm-UVC light protects fibroblast in dermal damaged site

○Kouji Narita^1,2, Yukihiro Morimoto^3,4,5, Hiroyuki Ohashi⁴, Tatsushi Igarashi⁴, Krisana Asano^2,3, Akio Nakane³ (¹Inst. for Animal Exp., Hirosaki Univ. Grad. Sch. of Med., ²Dept. Microbiol. and Immunol., Hirosaki Univ. Grad. Sch. Med., ³Dept. Biopolymer and Health Sci., Hirosaki Univ. Grad. Sch. Med., ⁴Ushio Inc., ⁵Inst. of Scientific and Industrial Res., Osaka Univ.)

Ultraviolet C (UVC) elicits anti-microbial property. 254 nm-UVC generating lamp is used as germicidal devices. However, 254 nm-UVC is carcinogenic and cataractogenic through DNA damage in dermal keratinocytes. We recently reported that 222 nm-UVC has the same level of germicidal effect as 254 nm-UVC against pathogenic bacteria, fungi and viruses. Different from 254 nm-UVC, 222 nm-UVC is harmless to keratinocytes because penetration of the light into the skin is blocked in stratum corneum. Therefore, 222 nm-UVC is harmless to dermis. However, impact of 222 nm-UVC to fibroblasts exposed to body surface in dermal defect site is not clarified. 222 nm- and 254 nm-UVC irradiation induced cytopathic effect to primary normal human dermal fibroblast cells, but fibroblasts covered with thin layer of 10% fetal calf serum were protected from 222 nm-UVC but not 254 nm-UVC. Irradiation with 254 nm-UVC induces cyclobutane pyrimidine dimer (CPD) in dermal damaged sites of the fibroblast, but 222 nm-UVC did not induce the CPD in fibroblasts. However, when 222 nm-UVC irradiation was performed under flow of PBS to eliminate wound exudate, CPD was detected in fibroblasts in wound. These results indicate that the 222 nm-UVC light irradiation is harmless to skin wound because the light is interfered by wound exudates.