Skin optical properties from 200 to 300 nm support far UV-C skin-safety in vivo

Daniela F Zamudio Díaz; Anna Lena Klein; Martin Guttmann; Paula Zwicker; Loris Busch; Marius Kröger; Holger Klose; Sascha Rohn; Johannes Schleusener; Martina C Meinke

doi:10.1016/j.jphotobiol.2023.112784

Skin optical properties from 200 to 300 nm support far UV-C skin-safety in vivo

J Photochem Photobiol B. 2023 Oct:247:112784. doi: 10.1016/j.jphotobiol.2023.112784. Epub 2023 Sep 4.

Authors

Affiliations

¹ Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Center of Experimental and Applied Cutaneous Physiology, Department of Dermatology, Venereology and Allergology, Charitéplatz 1, 10117 Berlin, Germany; Technische Universität Berlin, Institute of Food Technology and Food Chemistry, Gustav-Meyer-Allee 25, 13355 Berlin, Germany.
² Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Center of Experimental and Applied Cutaneous Physiology, Department of Dermatology, Venereology and Allergology, Charitéplatz 1, 10117 Berlin, Germany.
³ Ferdinand-Braun-Institut (FBH), Gustav-Kirchhoff-Str. 4, 12489 Berlin, Germany.
⁴ University Medicine Greifswald, Institute of Hygiene and Environmental Medicine, Ferdinand-Sauerbruch-Str., 17475 Greifswald, Germany.
⁵ artMED Private Practice for Plastic and Aesthetic Surgery, Friedrichstraße 61, 10117 Berlin, Germany.
⁶ Technische Universität Berlin, Institute of Food Technology and Food Chemistry, Gustav-Meyer-Allee 25, 13355 Berlin, Germany.
⁷ Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Center of Experimental and Applied Cutaneous Physiology, Department of Dermatology, Venereology and Allergology, Charitéplatz 1, 10117 Berlin, Germany. Electronic address: martina.meinke@charite.de.

PMID: 37690371
DOI: 10.1016/j.jphotobiol.2023.112784

Abstract

The growing threat of multi-drug resistant pathogens and airborne microbial diseases has highlighted the need to improve or develop novel disinfection methods for clinical environments. Conventional ultraviolet C (UV-C) lamps effectively inactivate microorganisms but are harmful to human skin and eyes upon exposure. The use of new 233 nm far UV-C LEDs as an antiseptic can overcome those limitations. In this research, the light penetration into the skin was elucidated for the UV-C region (<300 nm) by measuring the scattering and absorption of skin layers and inverse Monte Carlo simulation, and further confirmed by the first clinical pilot trial in which healthy volunteers were irradiated with a dose of 60 mJ/cm² at 233 nm. The radiation is strongly absorbed in the stratum corneum, resulting in minimal skin damage without inducing inflammatory responses. The results suggest that 233 nm far UV-C light emitting diodes (LEDs) could effectively inactivate microorganisms, while being safe and soft for the skin.

Keywords: 233 nm LED; Absorption coefficient; DNA damage; Effective scattering coefficient; Inflammatory reactions; MC simulations.