Development of a model to demonstrate photosensitizer-mediated viral inactivation in blood.

A model has been developed to demonstrate the use of photodynamic treatment (PDT) to eradicate viral contaminants from donated blood and blood products. Whole blood, spiked with vesicular stomatitis virus (VSV), was treated with the photosensitizer benzoporphyrin derivative-monoacid ring A (BPD-MA). After light activation of BPD-MA, a neutral red dye uptake assay was carried out to determine virus inactivation. Various drug incubation times and light intensities were tested as well as red cell lysis and distribution of VSV in blood. At BPD-MA concentrations between 2 and 4 μg per mL in whole blood, up to 107 VSV were inactivated. Several photosensitizers were also tested with this model to determine their relative efficacy in viral inactivation.