Formulation and in vitro evaluation of magnetoliposomes as a potential nanotool in colorectal cancer therapy.

Magnetoliposomes (MLPs) offer many new possibilities in cancer therapy and diagnosis, including the transport of antitumor drugs, hyperthermia treatment, detection using imaging techniques, and even cell migration. However, high biocompatibility and functionality after cell internalization are essential to their successful application. We synthesized maghemite nanoparticles (γ-Fe2O3) by oxidizing magnetite cores (Fe3O4) and coating them with phosphatidylcholine (PC) liposomes, obtained using the thin film hydration method, to generate MLPs. The MLPs were tested in vitro, using human tumor and non-tumor colon cell lines, for cytotoxicity, cell uptake and cellular distribution, and magnetically-induced cell mobility. In addition, blood cells biocompatibility studies were performed. The mean size of the MLPs, with a core of γ-Fe2O3 completely surrounded by PC liposomes, was 90 ± 20 nm, showing a soft magnetic character and a great biocompatibility in all the cell lines assayed including blood cells. Prussian blue staining showed a high MLP cell uptake with maximum internalization at 24 h. TEM analysis showed the MLPs surrounded by the cell membrane and in the cell periphery, suggesting internalization by endocytosis and/or macropinocytosis. Interestingly, the mitochondria presented MLP accumulations, particularly in tumor cells. Finally, MLPs within colon cancer cells were able to induce cell migration when a magnetic field was applied in vitro, indicating the functionality of our nanoformulation. A promising biomedical application of these MLPs is anticipated based on their physical, chemical and biological properties.