Gd (III) DOTA-Functionalized Phthalocyanine Nanodots for Magnetic Resonance Imaging and Photothermal/Photodynamic Therapy

The development of organic nanoagents that integrate diagnosis and therapy has gained considerable attention over the last decades. Here, phthalocyanine-based nanodots (ZnPc-NDs) are developed through a facile hydrothermal method. The self-aggregation of molecules in nanostructures facilitates the fluorescence quenching and nonradiative heat generation. Accordingly, ZnPc-NDs display the photodynamic and photothermal effect simultaneously upon near-infrared laser irradiation. To endow ZnPc-NDs with the diagnostic function, the surface of nanodots is functionalized with Gd(III) chelates to yield ZnPc-Gd, providing the magnetic resonance performances. The biocompatibility and high photocytoxicity of ZnPc-Gd toward HeLa cells are verified through the cell counting kit-8 method. Due to the presence of paramagnetic metal, ZnPc-Gd exhibits a distinct magnetic resonance signal in vitro and in vivo. Upon irradiation with a 808 nm laser, ZnPc-Gd can efficiently inhibit the growth of tumors with minor side effects. Thus, the as-prepared ZnPc-Gd can be utilized as a promising nanoagent for magnetic resonance imaging-guided cancer phototherapy.