Preparation and coercivity and saturation magnetization dependence of inductive heating property of Fe3O4 nanoparticles in an alternating current magnetic field for localized hyperthermia

The magnetite (Fe3O4) nanoparticles with different magnetic properties were prepared by coprecipitation of Fe3+ and Fe2+ with an aqueous NaOH solution. The inductive heating property of Fe3O4 nanoparticles in an alternating current (ac) magnetic field was investigated. The potential of Fe3O4 nanoparticles was evaluated for localized hyperthermia treatment of cancers. The maximum saturation magnetization Ms of Fe3O4 nanoparticles was 65.53 emu g (1), which was synthesized under the condition of Fe3+/Fe2+ molar ratio at 1.8:1. The Ms of Fe3O4 nanoparticles decreased, while the coercivity Hc increased with the increase of Fe3+/Fe2+ molar ratio. Exposed in the ac magnetic field for 29 min, the temperatures of physiological saline suspensions containing different Fe3O4 nanoparticles are 42-97.5 degrees C. The inductive heating property of Fe3O4 nanoparticles in the ac magnetic field decreased as He increased, while increased with the increase of Ms. The Fe3O4 nanoparticles will be useful as good thermoseeds for localized hyperthermia treatment of cancers. (C) 2008 Elsevier B.V. All rights reserved.