Enhancement of cytotoxicity of artemisinin toward cancer cells by transferrin-mediated carbon nanotubes nanoparticles.

Artemisinin (ART) is a kind of drug with an endoperoxide bridge which tends to react with Fe(2+) to generate radicals for killing cancer cells. However, simultaneous delivery of hydrophobic ART and Fe(2+) ions into cancer cells remains a major challenge. In this study, a multi-functional tumor-targeting drug delivery system employing hyaluronic acid-derivatized multi-walled carbon nanotubes (HA-MWCNTs) as drug carriers, transferrin (Tf) as targeting ligand and ART as a model drug for cancer treatment was constructed. This delivery system (HA-MWCNTs/Tf@ART) not only retained optical property of MWCNTs and cytotoxicity of ART but also demonstrated synergistic anti-tumor effect using ART and Tf. Compared with free ART, remarkably enhanced anti-tumor efficacy of this drug vehicle was realized both in cultured MCF-7 cells in vitro and in a tumor-bearing murine model in vivo, due to increased intracellular accumulation of ART and co-delivery of Tf and ART analogs. HA-MWCNTs/Tf@ART with laser irradiation demonstrated the highest inhibition effect compared to the other groups. This result may provide a new way of using promising natural drugs for cancer therapy.