Anti-hypoxia nanosized drug delivery systems improving cancer therapy

The abnormal tumor vascular system and long distances among cells inside tumors and blood vessels lead to restricted oxygen content and diffusion impairment in the tumor tissues, which are two essential factors contributing to hypoxia. Since hypoxia is an important feature of malignant solid tumors, it is closely related to the development of tumors and resistance to therapies. Recently, various anti-hypoxia treatments based on nanosized drug delivery systems (NDDSs) have been developed to enhance the efficacy of cancer therapy, providing a feasible solution for overcoming the obstacles to cancer treatments caused by hypoxia. In this review, the latest research progress on improving cancer therapy by anti-hypoxia NDDSs based on various mechanisms, including increasing oxygen supply, reducing oxygen consumption, and inhibiting hypoxia-related signaling pathways, is summarized. On the basis of discussing the advantages and shortcomings of these strategies, we propose possible directions and perspectives on further studies and clinical translation.