Photodynamic inactivation of Candida albicans by BAM-SiPc.

Photodynamic therapy is a treatment that combines the use of three non-toxic components, viz. photosensitiser, light and oxygen to cause localised oxidative photodamage. In the present study, the antifungal effect of the photosensitiser, BAM-SiPc, an unsymmetrical bisamino phthalocyanine, was investigated. BAM-SiPc was effective in photo-inactivating Candida albicans in a dose-dependent manner. The cell viability as determined by the clonogenic assay was reduced to c. 10% at 0.02 μmol l−1 BAM-SiPc with a total fluence of 12 J cm−2 at a cell density of 107 cells ml−1. A short incubation time of 5–15 min was sufficient to allow the photosensitiser to exert its optimal antifungal activity. Microscopical analysis showed that BAM-SiPc was effectively internalised by the fungal cells. Photodynamic treatment led to an increase in the intracellular reactive oxygen species level and disturbed the membrane integrity of the fungal cells. [ABSTRACT FROM AUTHOR]