Monoclonal Antibody-Guided Tumour-Targeted Hollow Virus-Like Cerium Oxide with Oxygen Self-Supply for Intensifying Photodynamic Therapy.

The hypoxic character of tumours and the poor targeting ability of photosensitizers often limit the efficacy of photodynamic therapy (PDT). In recent years, the discovery of metal nanoenzymes and nanocarriers has improved PDT. Thereby, to improve the effective utilization of photosensitizers and oxygen (O2 ) in tumours, herein, we report a nanosystem (LS-HB@HvCeO2 -NRP1 mAb, LHCN1) in which a hollow virus-like cerium oxide (HvCeO2 ) is surface-decorated with tumour-targeting neuropilin-1 monoclonal antibody (NRP1 mAb), and loaded with a photosensitizer (chlorin e6-C-15-ethyl ester, LS-HB). In vitro and in vivo experiments demonstrate that LHCN1 can efficiently accumulate within the tumour sites via the targeting guidance of NRP1 mAb and is then rapidly endocytosed into cells. Furthermore, HvCeO2 with catalase-mimetic activity can decompose the endogenous hydrogen peroxide (H2 O2 ) to promote O2 via the valence transformation between Ce4+ and Ce3+ , relieving tumour hypoxia and improving the PDT efficacy. Upon near-infrared laser irradiation, LS-HB produces large amounts of cytotoxic reactive oxygen species. Moreover, LHCN1 is used in fluorescence/photoacoustic multimodal imaging for in vivo drug localization, and its use in PDT evidently helps inhibit tumour growth with no apparent toxicity to normal tissues. Thus, LHCN1 may provide a promising strategy for precise tumour-specific diagnosis and treatment. This article is protected by copyright. All rights reserved.