Porous CeO2 nanorods loaded with indocyanine green for enhanced tumor-specific therapy

Abstract

Recently, catalytic therapy on the basis of Fenton reaction represents a very promising paradigm for potential cancer therapy, which has inspired great research interest and got fast progress. Nevertheless, it remains challenging to fabricate nanocatalytic systems that can precisely perform catalytic activity in tumor tissues without causing toxicity to adjacent normal tissues. Herein, we designed and fabricated a porous CeO2 nanorods that can selectively perform therapeutic activity in the weakly acidic tumor microenvironment via converting H2O2 into •OH to kill cancer cells, meanwhile, the normal tissues are protected by decomposing H2O2 into O2 in the physiological environment. Specifically, benefiting from the porous structure, such CeO2 nanorods could be loaded with Indocyanine green (ICG) that could both contribute itself to generate singlet oxygen (1O2) and convert near-infrared (NIR) light to hyperthermia. Once exposed to NIR light, on the one hand, the catalytic activity of CeO2 was significantly enhanced by photothermal effect of ICG for highly efficient tumor catalytic therapy; on the other hand, the generated hyperthermia and 1O2 by ICG can further synergistically enhance the therapy efficiency via directing killing cancer cells. The current study provides a proof-of-concept demonstration of tumor-specific therapy with minimal non-targeted toxicity.