The role of molecular oxygen in the photodynamic effect of phthalocyanines.

摘要: Phthalocyanines are a class of mammalian cell photosensitizers which may be useful in photodynamic therapy for cancer. Chloroaluminum phthalocyanine tetrasulfonate was incubated with Chinese hamster cells culture and exposed to white light at different concentrations oxygen. The ability the form colonies served as an end point photobiological effect dye. efficiency photoinactivation sensitized decreased decreasing oxygen concentration. Very little observed when atmosphere equilibrated oxygen-free nitrogen. At partial pressure 2.5 mm Hg, reduced by 50% compared ambient atmosphere. In attempt understand nature interaction between excited dyes oxygen, several phthalocyanines photogenerate singlet measured. Thus containing paramagnetic ions (copper, iron, vanadyl) do not generate 1O2 contradistinction diamagnetic metals (zinc aluminum). latter efficient photosensitizers, while former have if any activity. spite this correlation, intermediate involved cytotoxicity. reasons discussed.