Journal Article

Photodynamic Inactivation of Viruses: The Factors that Determine Rate and Extent of Inactivation

Abstract

Photodynamic inactivation (PDI) of viruses in solution has been reported and that singlet oxygen mediated oxidation is responsible for the inactivation. The capsids of non-enveloped viruses are possible targets for viral inactivation by singlet oxygen oxidation. In most of the previous PDI studies, much of the work has been focus on the quantitative aspects of the inactivation with little emphasis on the factors and targets of the PDI in viruses. In this work, we carried out the PDI of our model virusbacteriophage MS2 using different concentrations of photosensitiser-TMPyP in solution, different light intensities and at different times of light exposure (illumination). The results obtained in this study suggest that the concentration of the photosensitiser- TMPyP, time of illumination and light intensity all affect the rate and extent of PDI of MS2. Also, we observed that 0.1% (w/v) of humic acid gave 100 % protection to MS2 under the PDI conditions used. A plausible explanation for this include the humic acid quenched the singlet oxygen generated or shielded the virus from direct effect of singlet oxygen mediated damage. This work can lead way in providing needed information on all factors that should be considered when developing/establishing an optimal PDI conditions for the control of viruses.

Download pdf