Publications

Irradiation of human oral mucosa by 233 nm far UV‑C LEDs for the safe inactivation of nosocomial pathogens

J. Schleusener1, S.B. Lohan1, L. Busch1,2, D.F. Zamudio Díaz1,3, N. Opitz4, C. Sicher4, T. Lichtenthäler4, K. Danker5, S. Dommerich6, T. Filler7, M.C. Meinke1 & P. Zwicker4

Published in:

Sci. Rep., vol. 13, art. 22391, doi:10.1038/s41598-023-49745-3 (2023).

Abstract:

The inactivation of multi resistant pathogens is an important clinical need. One approach is UV-C irradiation, which was previously not possible in vivo due to cytotoxicity. Recently, far UV-C irradiation at λ < 240 nm was successfully used on skin with negligible damage. A potential application site is the nasal vestibule, where MRSA accumulates and cannot be treated using antiseptics. We irradiated 3D mucosa models and excised human mucosa with 222 and 233 nm far UV-C in comparison to 254 nm and broadband UV-B. Eradication efficiency was evaluated by counting colony forming units; irritation potential was evaluated by hen’s egg-chorioallantoic membrane assay and trans epithelial electrical resistance; cell viability was assessed by MTT. DNA damage and cell protective mechanisms were evaluated immunohistopathologically. On mucosa models, MRSA reduced by ≈ 5 log10 for 60 mJ/cm2 irradiation at 233 nm. A slightly increased cell viability was observed after 24 h. Lower doses showed lower irritation potential than the positive controls or commercial mouthwash, while 80 mJ/cm2 had strong irritation potential. DNA damage occurred only superficially and decreased after 24 h. On excised human mucosa, < 10% of keratinocytes were affected after 150 mJ/cm2 222 nm or 60 mJ/cm2 233 nm.

1 Center of Experimental and Applied Cutaneous Physiology, Department of Dermatology, Venereology and Allergology, Charité – Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Charitéplatz 1, 10117 Berlin, Germany
2 Department of Pharmaceutics and Biopharmaceutics, Philipps-Universität Marburg, Robert‑Koch‑Str. 4, 35032 Marburg, Germany
3 Technische Universität Berlin, Institute of Food Technology and Food Chemistry, Gustav‑Meyer‑Allee 25, 13355 Berlin, Germany
4 Institute of Hygiene and Environmental Medicine, University Medicine Greifswald, Ferdinand‑Sauerbruch‑Str., 17475 Greifswald, Germany
5 Institute of Biochemistry, Charité – Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt Universität zu Berlin, Charitéplatz 1, 10117 Berlin, Germany
6 Department of Otorhinolaryngology, Charité – Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Charitéplatz 1, 10117 Berlin, Germany
7 Ferdinand-Braun-Institut (FBH), Gustav‑Kirchhoff‑Str. 4, 12489 Berlin, Germany

© The Author(s) 2023
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