pH-Responsive drug vehicles targeting the specific extracellular pH of tumors have served as potent tools to overcome the limitation (e.g., low tumor seletivity) in antitumor drug delivery system. Here, researchers from the Catholic University of Korea describe the advantage of pH-responsive extracellular vesicles (HDEA@EVs) containing the hyaluronic acid grafted with 3-(diethylamino)propylamine (HDEA) and a model antitumor drug, doxorubicin (DOX). They demonstrate their physicochemical characteristics through in vitro cell endocytosis, in vitro tumor cell toxicity, in vivo biodistribution, and in vivo tumor regression efficacy experiments. Because the HDEA@EVs efficiently responded to extracellular tumor pH (pH 6.5) and actively bound to CD44 receptors on HCT-116 tumor cells, the EVs selectively inhibited CD44+ tumor cell growth in vitro, and CD44+ tumor development in vivo. From these results, the researchers conclude that HDEA@EVs can help in designing effective strategies for pharmacologic intervention in tumor therapy.
pH-responsive hyaluronate-anchored extracellular vesicles to promote tumor-targeted drug delivery
Lee H, Park H, Noh GJ, Lee ES. (2018) pH-responsive hyaluronate-anchored extracellular vesicles to promote tumor-targeted drug delivery. Carbohydr Polym 202:323-333. [abstract]