Nanotherapy Targeting the Tumor Microenvironment.

Cancer is characterized by high mortality and low curability. Recent studies have shown that the mechanism of tumor resistance involves not only endogenous changes to tumor cells, but also to the tumor microenvironment (TME), which provides the necessary conditions for the growth, invasion, and metastasis of cancer cells, akin to Stephen Paget's hypothesis of "seed and soil." Hence, the TME is a significant target for cancer therapy via nanoparticles, which can carry different kinds of drugs targeting different types or stages of tumors.