Germicidal Efficacy and Mammalian Skin Safety of 222-nm UV Light

• DOI: 10.1667/rr0010cc.1
• Publication Date: 2017-02-22T17:15:15Z
• Authors: Manuela Buonanno; Brian Ponnaiya; David Welch; Milda Stanislauskas; Gerhard Randers-P...; Lubomir Smilenov; Franklin D. Lowy; David M. Owens; David J. Brenner
• Keywords: Pyrimidine dimer; Human skin; Ultraviolet; Visible spectrum

We have previously shown that 207-nm ultraviolet (UV) light has similar antimicrobial properties as typical germicidal UV (254 nm), but without inducing mammalian skin damage. The biophysical rationale is based on the limited penetration distance of in biological samples (e.g. stratum corneum) compared with 254-nm light. Here we extended our previous studies to 222-nm and tested hypothesis there exists a narrow wavelength window far-UVC region, from around 200-222 nm, which significantly harmful bacteria, damaging cells tissues. used krypton-chlorine (Kr-Cl) excimer lamp produces bandpass filter remove lower- higher-wavelength components. Relative respective controls, measured: 1. vitro killing methicillin-resistant Staphylococcus aureus (MRSA) function fluence; 2. yields main UV-associated premutagenic DNA lesions (cyclobutane pyrimidine dimers 6-4 photoproducts) 3D human tissue model vitro; 3. eight cellular molecular damage endpoints exposed hairless mice vivo. Comparisons were made results conventional positive control. found kills MRSA efficiently but, unlike lamps it almost no not cytotoxic skin. As predicted by considerations agreement findings, range nm bacteria regardless their drug-resistant proficiency, effects associated exposure.