A fullerene based hybrid nanoparticle facilitates enhanced photodynamic therapy via changing light source and oxygen consumption.

• Type I (electron transfer) PDT of C60 is significantly enhanced by gold nanoparticles. • C60@GNPs can be excited under near-infrared light, which has a high tissue penetration. • C60@GNPs with near-infrared light irradiation can obtain oxygen non-dependent of PDT. Recently, fullerene (C60) has been widely used as a nano photosensitizer (PS) for tumor related photodynamic therapy (PDT). However, current PDT based on C60 is severely restricted by the visible light source (shallow tissue penetrating depth) and oxygen dependent (tumor hypoxia). Therefore, taking advantages of the surface plasmon resonance (SPR) effect of gold nanoparticles (GNPs) and "electronic sponge" property of C60, a C60 based hybrid nanostructured photosensitizer (C60@GNPs) with high light stability, near infrared light (NIR) excitation, and oxygen non-dependent properties was rational designed according to the mechanism of PDT. Compared with C60, after GNPs in-situ synthesis, the PDT mechanism of C60@GNPs changed from type II to type I, and the main product of PDT changed from singlet oxygen to hydroxyl radicals. Furthermore, C60@GNPs hybrid could efficiently generate hydroxyl radicals under NIR light excitation even in the hypoxia condition. These results suggest that C60@GNPs hybrid has a great potential for in vivo PDT applications. [ABSTRACT FROM AUTHOR]