Dual targeted delivery of doxorubicin to cancer cells using folate-conjugated magnetic multi-walled carbon nanotubes.

By combining the advantage of multi-walled carbon nanotubes (MWCNTs) and iron oxide magnetic nanoparticles (MNs), we develop a magnetic dual-targeted nanocarrier for drug delivery. MWCNTs were functionalized with poly(acrylic acid) through free radical polymerization, decorated with MNs, conjugated with a targeting ligand folic acid (FA), for loading of an anti-cancer drug doxorubicin (DOX). The proposed methodology provides dual targeted delivery of the anti-cancer drug to cancer cells under the guidance of a magnetic field and through ligand-receptor interactions. The chemico-physical properties of the nanocarrier were characterized, in addition to its drug loading efficiency and drug releasing characteristics. Doxorubicin could be loaded to MWCNTs with high efficiency via π-π stacking and hydrogen bonding and showed enhanced cytotoxicity toward U87 human glioblastoma cells compared with free DOX. From transmission electron microscopy and confocal laser scanning microscopy, we confirmed that DOX-FA-MN-MWCNT could be efficiently taken up by U87 cells with subsequent intracellular release of DOX, followed by transport of DOX into the nucleus with the nanocarrier left in the cytoplasm. These properties make the magnetic nanocarrier a potential candidate for targeted delivery of DOX for cancer treatment.