Drug resistant bacteria, such as MRSA, and airborne-transmitted microbes, such as influenza and TB, together present major health issues both in the developed and the developing world, with major health care and economic consequences. Recent research from Columbia University Medical Center demonstrated that single- wavelength far-UVC photons can kill bacteria and viruses while it cannot penetrate either the human stratum corneum (the outer dead-cell skin layer), nor the ocular cornea, nor the corneal tear-film layer, nor even the cytoplasm of individual human cells. In particular, the results teste both in vitro and in vivo have shown that several far-UVC wavelengths (such as 207 and 222 nm) are as efficient as conventional mercury containing germicidal UV lamp in inactivating both drug-resistant bacteria (e.g. MRSA) and viruses (e.g. H1N1), but these two far UVC wavelengths induce no damage to skin or to eyes, for a wide range of clinical endpoints, in contrast to a conventional broad-spectrum germicidal lamp. In this program, the team of Columbia University and Eden Park Illumination propose a novel, efficient disinfection tool which can be scalable and affordable. The team will develop uniform and flat lamps having anti-microbial advantages over conventional cylindrical UV lamps, but without the safety hazards. Eden Park have commercialized a new generation of UV light tiles with a patented microcavity plasma technology, producing lamps with a scalable, slim form factor for uniformly treating large surfaces. Based on confinement of low temperature plasma within large arrays of microcavities, this technology is ideally-suited for the efficient, inexpensive production of excimer-based 222 nm UV lamp. The technology of a monochromatic excimer lamp emitting 222 nm UV radiation will have two initial applications: 1) reducing surgical site infections, in which 222 nm photons will continuously illuminate the wound during surgery, and 2) minimizing airborne transmission of microbes such as TB and influenza, in which whole-room illumination will be used. Both have been successfully demonstrated with conventional germicidal lamps but widespread use has been limited due to the associated health hazards of conventional lamps. The Phase I Project Aims are first, to design and develop 222 nm microplasma UV flat lamp optimized for this germicidal application, and second, to use the lamp to demonstrate effective germicidal properties.
The first Aim will involve design and optimization of a microplasma-based monochromatic far-UVC flat lamp optimized for germicidal applications, with the milestone of a 222 nm flat UV lamp without higher wavelength contaminants, and with a lamp structure and gas mixture optimized for long lifetime.
The second Aim i s to demonstrate the efficacy of this 222 nm microplasma flat lamp for anti-bacterial efficiency in an in vivo wound model and for anti-viral efficiency in an airborne aerosol model. The milestones here are to demonstrate appropriate levels of MRSA killing in a murine model of surgical site infection, and appropriate levels of H1N1 influenza virus killing in an airborne aerosol model.
Drug resistant bacteria, such as MRSA, and airborne-transmitted microbes, such as influenza and TB, present major health issues both in the developed and the developing world, with major human and economic consequences. UV from a standard germicidal lamp is a highly-efficient anti-microbial modality, effective both against bacteria and viruses, but is not practical for use where people are present because it is a human health hazard, being both carcinogenic and cataractogenic. Based on biophysical principles, and supported by preliminary studies, it is proposed that an optimized far-UVC light (~222 nm) from an inexpensive excimer lamp will not produce these health hazards, but will have all the anti-microbial advantages of UV germicidal lamps, both for drug-resistant bacteria (to reduce surgical site infection) and for viruses (to reduce airborne transmission).
|Welch, David; Buonanno, Manuela; Grilj, Veljko et al. (2018) Far-UVC light: A new tool to control the spread of airborne-mediated microbial diseases. Sci Rep 8:2752|
|Welch, David; Randers-Pehrson, Gerhard; Spotnitz, Henry M et al. (2017) UNLAMINATED GAFCHROMIC EBT3 FILM FOR ULTRAVIOLET RADIATION MONITORING. Radiat Prot Dosimetry 176:341-346|
|Buonanno, Manuela; Ponnaiya, Brian; Welch, David et al. (2017) Germicidal Efficacy and Mammalian Skin Safety of 222-nm UV Light. Radiat Res 187:483-491|