Folate-Modified pH and ROS Dual-Responsive Polymeric Nanocarriers for Targeted Anticancer Drug Delivery

The tumor microenvironment is distinguished from normal tissues, such as the acidic microenvironment, elevated reactive oxygen species (ROS) levels, and overexpressed specific receptors on the cell surface. According to these unique hallmarks of cancer, stimulus-responsive drug carriers can be designed for targeted anticancer drug delivery and specific drug release in tumor tissues. Herein, a folate-modified pH/ROS dual-responsive polymeric micellar nanosystem was developed for the targeted delivery of doxorubicin (DOX). The drug release profile suggested a sustained drug release from the polymeric micelles and an accelerated drug release at lower pH and higher ROS levels. The cellular uptake assay indicated that the polymeric micelles were internalized by HepG2 cells and that the cellular uptake of micelles can be enhanced by folate modification through a receptor-mediated endocytosis pathway. Furthermore, the folate-modified pH/ROS dual-responsive polymeric micellar nanocarriers demonstrated enhanced inhibition on the migration of HepG2 cells in the cell scratch test and showed improved suppression on the proliferation of HepG2 cells and a lower IC 50 than the nonfolate micelles in the cell viability test, indicating the desirable in vitro anticancer efficiency of the nanosystem.