Design and challenge of cancer nanomedicine

Anticancer nanomedicines can alleviate adverse effects of chemotherapeutic drugs and some are used in clinic, but they fail to improve the therapeutic efficacy. For rational design of next-generation highly effective cancer nanomedicines, this review analyzes the tumor-targeted drug delivery process of intravenously administered nanomedicines as a five-step CAPIR cascade, and further concludes that stability, surface and size nanoproperties (i.e., 3S nanoproperties) self-adaptive to the CAPIR steps via 3S nanoproperty transitions, which are the key to a nanomedicine to efficiently accomplish the delivery cascade and thus achieve high therapeutic efficacy. The reported strategies to realize the 3S nanoproeprty are summarized. Furthermore, the bottleneck of the delivery process, the inherent poor tumor penetration (low P ) of nanomedicines and the methods and their limitations in improving P are summarized. Finally, the challenges of nanomedicine in clinical translation are discussed.