Photodynamic activity of a hybrid nanostructure based on a polycationic fullerene derivative and phthalocyanine dye photosens

229 As known, fullerenes are photoexcited to a triplet state in 100% quantum yield, which then is deacti vated to generate, depending on the polarity of a medium, either singlet oxygen О2 or superoxide radi cal anions and other active radicals [1]. Numerous studies have addressed the photodynamic effect of fullerene and their derivatives: the generation of active radicals upon photoexcitation is responsible for dam age of DNA, proteins, and membranes, as well as for the suppression of the reproduction of tumor cells, viruses, and bacteria [2]. However, the efficiency of the photodynamic action of fullerenes and the pros pects for their application in medicine are essentially limited by the weak absorption by fullerenes of visible light, especially in the range 650–800 nm, which is most suitable for photodynamic therapy. The photodynamic effect of fullerenes can be con siderably enhanced by creating hybrid nanostructures − О2 . (HNSs) via the formation of a fullerene complex with a dye that efficiently absorbs visible light [3]. In such a complex, the dye can efficiently absorb light and transfer excitation energy or electron to the fullerene. Further excitation transfer or electron transfer from the fullerene to molecular oxygen will generate active oxygen species. The creation of such an HNS based on fullerene and a dye can thereby significantly enhance the efficiency of photodynamic therapy.