Synthesis and characterization of recyclable clusters of magnetic nanoparticles as doxorubicin carriers for cancer therapy

This study focuses on the synthesis and characterization of recyclable clusters of magnetic nanoparticles (CMNPs) as doxorubicin carriers for cancer therapy. Fe3O4 nanoparticles were used as magnetically responsive carriers, the modified polyethylene glycol dicarboxylic acid (APS-PEG-TFEE) acted as a steady bridge between Fe3O4 and drug. The prepared CMNPs exhibited a size within 20 nm, good stability and super-paramagnetic responsibility (M-s 62.02 emu/g); doxorubicin (DOX) can be successfully loaded to CMNPs at a loading rate of 76.19% by electrostatic interaction. Moreover, the release studies in vitro showed that the drug-loaded carriers (CMNPs-DOX) had excellent pH-sensitivity, 76.16% of DOX was released within 72 h at pH 4.0, and the secondary drug loading rate was nearly 52%. WST-1 assays in model breast cancer cells (MCF-7) demonstrated that CMNPs-DOX exhibited high anti-tumor activity, while the CMNPs were practically non-toxic. Thus, our results revealed that CMNPs would be a competitive candidate for drug delivery carriers and CMNPs-DOX could be used in targeted cancer therapy in the near future. (C) 2014 Elsevier B.V. All rights reserved.