Cerium-Based Nanoparticles for Cancer Photodynamic Therapy*

Metal-andmetal-oxide-based nanoparticles have beenwidely exploited in cancer photodynamic therapy (PDT). Among these materials, cerium-basednanoparticles have drawn extensive attentiondue to their superior biosafety and distinctive physicochemical properties, especially the reversible transition between the valence states of Ce(III) and Ce(IV). In this review, the recent advances in the use of cerium-based nanoparticles as novel photosensitizers for cancer PDT are discussed, and the activation mechanisms for electron transfer to generate singlet oxygen are presented. In addition, the types of cerium-based nanoparticles usedforPDTof cancer are summarized.Finally, the challenges and prospects of clinical translations of cerium-based nanoparticles are briefly addressed.