TBCA and breast cancer: After intravenous injection, firstly, cFA could actively target the breast cancer tissues by the selective recognition of folate receptor (FR); then, upon arrival at the tumor microenvironment, the acid-cleavable FA and dNP2 dual modified nanostructured lipid carrier (cFA/dNP2-GA/PTX-NLC) exhibited sensitive cleavage of folic acid (FA), which could reduce the hindrance effect of FA to maximize the dNP2 cell-penetrating properties.