Chemotherapy is an important cancer treatment strategy and one of the few available options for treating metastatic tumors or lesions that cannot be removed by surgery. Unfortunately, classic chemotherapy drugs have limited therapeutic potential and often cause serious side effects (Yan et al., Dose Response 18:1559325820936161, 2020). Because of the limitations of conventional chemotherapies, the cancer chemotherapy paradigm has now shifted from conventional methods to tumor-specific targeting methods, which may maximize treatment efficiency and minimize related toxic effects of therapeutic molecules. Using nanocarriers to deliver chemotherapeutic drugs is a promising chemotherapy strategy. Nanoformulations used to deliver chemotherapeutic agents include liposomes, polymeric nanoparticles, and polymeric micelles (Fig. 3.1). The use of nanocarriers as a delivery vehicle for chemotherapeutic drugs has the following advantages: (1) Improved solubility of poorly soluble drugs, which avoids using toxic solubilizers to dissolve poorly soluble chemotherapeutic drugs (Bernabeu et al., Int J Pharm 526:474-495, 2017). (2) Increased circulation time and improved stability of chemotherapy drugs. (3) Preferentially aggregated nanocarriers at the tumor site due to the enhanced permeability and retention effect, thereby improving the efficacy and reducing the side effects of chemotherapy.