Photodynamic inactivation of selected bovine viruses by isomeric cationic tetra-platinated porphyrins

Porphyrin-based photodynamic processes have been used for the inactivation of microorganisms and treatment of tumors. The virucidal activity of porphyrins 3-PtTPyP and 4-PtTPyP was investigated against bovine viruses representative of the main structural groups (enveloped/nonenveloped, DNA/RNA: BVDV, BoHV-1, BAV and BEV), and against two epitheliotropic viruses (VSV and VACV). Viral suspensions were incubated at 0.91 mu mol/L-1 and exposed to a white-light LED array source (25 mW.cm(-2) ; 90 J.cm(-2) ) for 0, 15, 30 and 60 min followed by determination of the remaining virus titers. Porphyrin 3-PtTPyP reduced almost 6 log of VSV and 3.5 log of BVDV titers after 15 min and complete virus photoinactivation was achieved after 30 min. 4-PtTPyP at 0.91 mu mol.L-1 produced reduction of titers of all enveloped virus depending on the time of light irradiation. No virucidal activity of any of the porphyrins was observed for non-enveloped viruses and these results showed the potential of porphyrins to inactivate viruses in premises.