Affiliations: Laboratoire de Photobiologie (INSERM U 312), Muséum National d’Histoire Naturelle, 43 rue Cuvier, 75231 Paris Cedex 05, France | Laboratoire de Biologie Parasitaire (ERS 156 CNRS), Muséum National d’Histoire Naturelle, 61 rue Buffon, 75231 Paris Cedex 05, France | Laboratoire de Biochimie, Centre Hospitalier Universitaire d’Amiens, Hôpital Nord, 80054 Amiens Cedex 01, France | Département d’Hémorhéologie et d’Hématologie, LEMTA‐UMR CNRS et FR CNRS W0070, Faculté de Médecine, Bat. E Brabois, 54200 Vandoeuvre Les Nancy, France
Abstract: Photochemical methods using photosensitizing photoactive drugs are very promising for blood product decontamination. Depending on the nature of virus – or parasite – bound photosensitizers, direct photochemical addition to virus components (DNA, proteins and lipids) occurs or the photosensitizer produces singlet oxygen inactivating viruses or parasites. The main advantage of this method is the lack of dark toxicity of presently used photosensitizers (psoralens, methylene blue, merocyanine 540, porphyrins/chlorins, phthalocyanines). In blood, the uptake of photosensitizers is not fully specific for infected cells. Therefore, normal cells and plasma proteins may suffer from the photodynamic action. Consequently, cell metabolism, rheological properties and surface markers may be altered and a slow loss of functionality occurs during storage. Data regarding pathogen inactivation in plasma and blood proteins, platelets and RBC concentrates are presented in comparison with the effect of photosensitization on normal blood components. Means for protecting normal components from photosensitization are also evaluated.
Keywords: Photosensitizers, photodynamic reactions, virus, parasites, singlet oxygen, membranes
