Tailoring biocompatible Fe_3O_4 nanoparticles for applications to magnetic hyperthermia

摘要

Magnetite based nanoparticles functionalized with different ligands have been obtained by optimization of two synthetic methods. Gold surrounded Fe_3O_4 nanoparticles capped with oleic acid and oleylamine were achieved by thermal decomposition of metallo-organic precursors. By this way nanoparticles with perfectly defined size within 3.5 run to 7 nm in diameter and organic content from 16.1% to 40.9 % were obtained. Precipitation of iron(II) chloride in basic solution yield magnetite nanoparticles between 20 and 40 nm with contents of organic ligands of 3 - 12 %. The samples have been characterized by X-ray diffraction, transmission electron microscopy and thermogravimetric measurements. A complete magnetic study has been performed by means of a SQUID magnetometer and electron magnetic resonance (EMR), showing the influence of capping covering on the superparamagnetic behaviour. The citotoxicity and interaction with HeLa cells was evaluated for some of the preparations. Finally, the specific absorption rate (SAR) was calculated to compare the efficiency of heating each sample for the various applied magnetic fields.