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Studies of inactivation mechanism of non-enveloped icosahedral virus by a visible ultrashort pulsed laser.

Tsen SW, Kingsley DH, Poweleit C, Achilefu S, Soroka DS, Wu TC, Tsen KT - Virol. J. (2014)

Bottom Line: These studies provide fundamental knowledge on photon-virus interactions on femtosecond time scales.From the analysis of the transmission electron microscope (TEM) images of viral particles before and after USP laser irradiation, the locations of weak structural links on the capsid of MNV-1 were revealed.We envision that this non-invasive, efficient viral eradication method will find applications in the disinfection of pharmaceuticals, biologicals and blood products in the near future.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Physics, Arizona State University, Tempe, Arizona 85287, USA. tsen@asu.edu.

ABSTRACT

Background: Low-power ultrashort pulsed (USP) lasers operating at wavelengths of 425 nm and near infrared region have been shown to effectively inactivate viruses such as human immunodeficiency virus (HIV), M13 bacteriophage, and murine cytomegalovirus (MCMV). It was shown previously that non-enveloped, helical viruses such as M13 bacteriophage, were inactivated by a USP laser through an impulsive stimulated Raman scattering (ISRS) process. Recently, enveloped virus like MCMV has been shown to be inactivated by a USP laser via protein aggregation induced by an ISRS process. However, the inactivation mechanism for a clinically important class of viruses--non-enveloped, icosahedral viruses remains unknown.

Results and discussions: We have ruled out the following four possible inactivation mechanisms for non-enveloped, icosahedral viruses, namely, (1) inactivation due to ultraviolet C (UVC) photons produced by non-linear optical process of the intense, fundamental laser beam at 425 nm; (2) inactivation caused by thermal heating generated by the direct laser absorption/heating of the virion; (3) inactivation resulting from a one-photon absorption process via chromophores such as porphyrin molecules, or indicator dyes, potentially producing reactive oxygen or other species; (4) inactivation by the USP lasers in which the extremely intense laser pulse produces shock wave-like vibrations upon impact with the viral particle. We present data which support that the inactivation mechanism for non-enveloped, icosahedral viruses is the impulsive stimulated Raman scattering process. Real-time PCR experiments show that, within the amplicon size of 273 bp tested, there is no damage on the genome of MNV-1 caused by the USP laser irradiation.

Conclusion: We conclude that our model non-enveloped virus, MNV-1, is inactivated by the ISRS process. These studies provide fundamental knowledge on photon-virus interactions on femtosecond time scales. From the analysis of the transmission electron microscope (TEM) images of viral particles before and after USP laser irradiation, the locations of weak structural links on the capsid of MNV-1 were revealed. This important information will greatly aid our understanding of the structure of non-enveloped, icosahedral viruses. We envision that this non-invasive, efficient viral eradication method will find applications in the disinfection of pharmaceuticals, biologicals and blood products in the near future.

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The fraction of survival as a function of laser power density for a MNV-1 sample. A rapid decrease of the fraction of survival has been found at a laser power density of around 80 MW/cm2.
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Figure 2: The fraction of survival as a function of laser power density for a MNV-1 sample. A rapid decrease of the fraction of survival has been found at a laser power density of around 80 MW/cm2.

Mentions: To gain better insight into the mechanism of inactivation for these non-enveloped, icosahedral viruses by USP laser irradiation, we measured the fraction of MNV-1 survival as a function of laser power density, which is shown in Figure 2 in natural logarithm (ln) scale. The laser exposure time was 2 hours. Here, the fraction of survival is defined as the reciprocal of the load reduction. The fraction of virus survival has been found to decrease as the laser power density increases in a continuous fashion up to about 80 MW/cm2. As the laser power density increases beyond 80 MW/cm2, the fraction of survival drops precipitously.


Studies of inactivation mechanism of non-enveloped icosahedral virus by a visible ultrashort pulsed laser.

Tsen SW, Kingsley DH, Poweleit C, Achilefu S, Soroka DS, Wu TC, Tsen KT - Virol. J. (2014)

The fraction of survival as a function of laser power density for a MNV-1 sample. A rapid decrease of the fraction of survival has been found at a laser power density of around 80 MW/cm2.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC3924410&req=5

Figure 2: The fraction of survival as a function of laser power density for a MNV-1 sample. A rapid decrease of the fraction of survival has been found at a laser power density of around 80 MW/cm2.
Mentions: To gain better insight into the mechanism of inactivation for these non-enveloped, icosahedral viruses by USP laser irradiation, we measured the fraction of MNV-1 survival as a function of laser power density, which is shown in Figure 2 in natural logarithm (ln) scale. The laser exposure time was 2 hours. Here, the fraction of survival is defined as the reciprocal of the load reduction. The fraction of virus survival has been found to decrease as the laser power density increases in a continuous fashion up to about 80 MW/cm2. As the laser power density increases beyond 80 MW/cm2, the fraction of survival drops precipitously.

Bottom Line: These studies provide fundamental knowledge on photon-virus interactions on femtosecond time scales.From the analysis of the transmission electron microscope (TEM) images of viral particles before and after USP laser irradiation, the locations of weak structural links on the capsid of MNV-1 were revealed.We envision that this non-invasive, efficient viral eradication method will find applications in the disinfection of pharmaceuticals, biologicals and blood products in the near future.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Physics, Arizona State University, Tempe, Arizona 85287, USA. tsen@asu.edu.

ABSTRACT

Background: Low-power ultrashort pulsed (USP) lasers operating at wavelengths of 425 nm and near infrared region have been shown to effectively inactivate viruses such as human immunodeficiency virus (HIV), M13 bacteriophage, and murine cytomegalovirus (MCMV). It was shown previously that non-enveloped, helical viruses such as M13 bacteriophage, were inactivated by a USP laser through an impulsive stimulated Raman scattering (ISRS) process. Recently, enveloped virus like MCMV has been shown to be inactivated by a USP laser via protein aggregation induced by an ISRS process. However, the inactivation mechanism for a clinically important class of viruses--non-enveloped, icosahedral viruses remains unknown.

Results and discussions: We have ruled out the following four possible inactivation mechanisms for non-enveloped, icosahedral viruses, namely, (1) inactivation due to ultraviolet C (UVC) photons produced by non-linear optical process of the intense, fundamental laser beam at 425 nm; (2) inactivation caused by thermal heating generated by the direct laser absorption/heating of the virion; (3) inactivation resulting from a one-photon absorption process via chromophores such as porphyrin molecules, or indicator dyes, potentially producing reactive oxygen or other species; (4) inactivation by the USP lasers in which the extremely intense laser pulse produces shock wave-like vibrations upon impact with the viral particle. We present data which support that the inactivation mechanism for non-enveloped, icosahedral viruses is the impulsive stimulated Raman scattering process. Real-time PCR experiments show that, within the amplicon size of 273 bp tested, there is no damage on the genome of MNV-1 caused by the USP laser irradiation.

Conclusion: We conclude that our model non-enveloped virus, MNV-1, is inactivated by the ISRS process. These studies provide fundamental knowledge on photon-virus interactions on femtosecond time scales. From the analysis of the transmission electron microscope (TEM) images of viral particles before and after USP laser irradiation, the locations of weak structural links on the capsid of MNV-1 were revealed. This important information will greatly aid our understanding of the structure of non-enveloped, icosahedral viruses. We envision that this non-invasive, efficient viral eradication method will find applications in the disinfection of pharmaceuticals, biologicals and blood products in the near future.

Show MeSH
Related in: MedlinePlus