Low-Dose X-ray Activation of W(VI)-Doped Persistent Luminescence Nanoparticles for Deep-Tissue Photodynamic Therapy

Although photodynamic therapy (PDT) has served as an important strategy for treatment of various diseases, it still experiences many challenges, such as shallow penetration of light, high-dose light irradiation, and low therapy efficiency in deep tissue. Here, a low-dose X-ray-activated persistent luminescence nanoparticle (PLNP)-mediated PDT nanoplatform for depth-independent and repeatable cancer treatment has been reported. In order to improve therapeutic efficiency, this study first synthesizes W(VI)-doped ZnGa2O4:Cr PLNPs with stronger persistent luminescence intensity and longer persistent luminescence time than traditional ZnGa2O4:Cr PLNPs. The proposed PLNPs can serve as a persistent excitation light source for PDT, even after X-ray irradiation has been removed. Both in vitro and in vivo experiments demonstrate that low-dose (0.18Gy) X-ray irradiation is sufficient to activate the PDT nanoplatform and causes significant inhibitory effect on tumor progression. Therefore, such PDT nanoplatform will provide a promising depth-independent treatment mode for clinical cancer therapy in the future.