Submitted to: Virology Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/30/2014
Publication Date: 2/5/2014
Citation: Tsen, S.D., Kingsley, D.H., Poweleit, C., Achilefu, S., Soroka, D.S., Wu, T., Tsen, K. 2014. Studies of Inactivation Mechanism of non-enveloped icosahedral viruses by a visible ultrashort pulsed laser. Virology Journal. 11:20. Interpretive Summary: Ultra-short pulse lasers producing 425 nm visible blue light and 850 nm infrared radiation have previously been shown to non-thermally inactivate non-enveloped icosahedral viruses, which are a significant problem for the food and pharmaceutical industries. In this publication, we evaluate potential mechanism by which laser light may cause inactivation of murine norovirus (MNV) and an artificially-constructed human papilloma virus. MNV is genetically-related research surrogate for human noroviruses, which currently cause the majority of food-borne illness in the US. We find that the laser is inducing high frequency acoustic waves that are shattering the virus capsids. We hope to develop this inactivation method as a virus disinfection method suitable for food and pharmaceutical products.
Technical Abstract: The inactivation mechanism of ultrashort pulsed laser irradiation at a wavelength of 425 nm has been studied using two different-sized, non-enveloped icosahedral viruses, murine norovirus-1 (MNV-1) and human papillomavirus-16 (HPV-16) pseudovirions. Our experimental results are consistent with a model in which inactivation is induced by an impulsive stimulated Raman scattering process. Experimental evidence and arguments are presented, which eliminate potential alternative mechanisms, such as generation of ultraviolet C photons, macro- and micro-thermal heating, or single photon absorption by chromophores and subsequent generation of reactive oxygen or other free radical species. Results indicate that impulsive stimulated Raman scattering perturbs the icosahedral capsids via disruption of hydrogen bonds and hydrophobic interactions resulting in disassembly of the capsid. These studies provide fundamental information on photon-virus interactions on a femtosecond time scale. The weak structural links on the capsid of virus are for the first time revealed. This knowledge of weak structural links will aid our understanding of the structure of the non-enveloped, icosahedral viruses. Direct demonstration that impulsive stimulated Raman scattering induces acoustic waves capable of destroying non-enveloped viruses heralds a new and unique method for disinfection for viruses that potentially contaminate biologicals, blood products, and foods.