Preparation and properties of folic acid-targeted pH-responsive drug-loaded micelles

In this study, a polymeric micelles material was prepared for tumor-targeted drug delivery using folic acid (FA) as targeting ligand. The polymeric material was prepared through combination of FA-modified methoxy polyethylene glycol (mPEG) and D-α-vitamin E succinate (VES) by pH-sensitive acetal bond, which was labeled as FA-PEG-OCO-VES. The prepared micelles were characterized by various testing methods. The results showed that the FA-PEG2000-OCO-VES micelles are in uniform spherical shape with diameter about 150 nm, which was selected for drug loading and release experiment. Quercetin (QU) was used as anticancer drug model in this study. The maximum encapsulation efficiency of FA-PEG2000-OCO-VES micelles was 72.49 ± 2.85%, and drug loading efficiency was 12.65 ± 0.48%. In vitro drug release experiments and release mechanism study showed that the accumulative release of QU was related to pH value. The hemolysis test and in vitro cytotoxicity assay displayed that the micelles have good biocompatibility. Targeting studies and in vitro anticancer activity experiments have shown that micelles could actively target overexpression receptors on the surface of tumor cells and enter breast cancer cells through endocytosis, inhibiting the proliferation of cancer cells after drug release. Therefore, FA-PEG2000-OCO-VES micelles are expected to be a promising drug carrier in the field of cancer therapy.