Engineering of an antitumor (core/shell) magnetic nanoformulation based on the chemotherapy agent ftorafur

The efficacy and safety of chemotherapy is conditioned by the very high drug doses needed to obtain an efficient therapeutic activity, the poor pharmacokinetics of anticancer drugs, and the frequent multi-drug resistance of cancer cells. The application of nanotechnology strategies in oncology has revolutionized the transport of drugs to cancer, allowing the appearance of new treatments with an improved specificity. In order to enhance the antitumor activity of ftorafur along with an overcome of its important limitations, we investigated the development of a magnetically responsive nanoformulation with very appropriate drug delivery properties. The formulation of the ftorafur-loaded iron oxide/chitosan (core/shell) nanocomposite was based on a coacervation method. The main factors determining the vehiculization of the chemotherapy agent were analyzed. Compared to surface adsorption onto the preformed magnetic nanoparticles, ftorafur entrapment into the polymeric shell resulted in a much better drug loading and in a slower (prolonged) ftorafur release profile. Such stimuli-sensitive nanoformulation hold very important properties (e.g., magnetic targeting capabilities, blood compatibility, high drug loading, and little burst release) for an efficient delivery of ftorafur to tumors. (C) 2011 Elsevier B.V. All rights reserved.