Monochromatic 222 nm UV light: Development of a safe, cost-effective technology for the efficient reduction of bacterial and viral infection and transmission

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Drug resistant bacteria such as MRSA, and airborne-transmitted microbes such as influenza and TB, present significant health issues, with major healthcare and economic consequences. UV light is a well-established highly-efficient anti-microbial modality, effective both against both bacteria and viruses. However it is not possible to use UV sterilization in scenarios where people are present because it is both carcinogenic and cataractogenic. Based on basic physics principles and supported by our Preliminary and Phase I Studies, far- UVC light (~222 nm generated from a KrCl excimer lamp) has all the anti-microbial advantages of conventional germicidal UV lamps, but without the corresponding human safety hazards. Thus the many demonstrated in-air anti-microbial applications of germicidal UV lamps, which cannot currently be applied when humans are present, can now be considered as potentially practical in the presence of humans. The market is twofold: Initially for hospitals, in operating rooms for irradiating above incisions during surgery to reduce surgical site infection rates. Secondly for public locations such as schools, hospitals, doctors offices, airports, airplanes and the food preparation industry, to reduce airborne transmission of viruses including influenza and measles, and bacteria such as TB. A key advantage is that UV bacterial killing is independent of drug resistance, so our approach addresses the ever-growing issue of “superbugs”. Neither higher (>230 nm) nor lower (<200 nm) wavelengths have the desired properties. Our products will be inexpensive, long-lived far-UVC excimer lamps, emitting at 222 nm and with minimal higher-wavelength emission. No such 222 nm lamp is currently available and, without a new technological breakthrough, appropriate LEDs are not practical in the relevant wavelength range below 230 nm. In Phase I we developed a high-intensity 222 nm excimer lamp with a lifetime of >5,000 h, and minimal emissions at higher wavelengths. In Phase II we will design, fabricate and test large area (>300 cm2) 222 nm excimer lamps with a further 5-fold intensity increase to >20 mW/cm2. Fabrication processes will be optimized to reduce costs and a matching filtered power supply developed. 222 nm light is safe for human exposure based on pure physics: 222 nm light cannot penetrate through the skin outer dead cell layer, nor the eye's surface tear film layer, nor into skin microbiome biofilms. This has been confirmed with our short-term safety studies, but we recognize the need for confirmatory long-term safety data. In Phase I we demonstrated that 222 nm light does not cause biological damage to the skin or eye, using relevant short-term in-vivo endpoints. In Phase II we will extend these in-vivo safety studies to prolonged (60 weeks) far-UVC exposures and long-term endpoints (skin cancer, skin microbiome, ocular damage). A conventional germicidal UV lamp designed for management of bacteria in open wounds has FDA 510(k) approval and will be the primary predicate device for our initial 510(k) application