Preparation of magnetite aqueous dispersion for magnetic fluid hyperthermia

An aqueous magnetic suspension was prepared by dispersing amphiphilic co-polymer-coated mono-dispersed magnetite nanoparticles synthesized through thermal decomposition of iron acetylacetonate (Fe(acac)(3)) in a mixture of oleic acid and oleylamine. The average diameter of narrow-size-distributed magnetite nanoparticles varied between 5 and 12 nm depending on the experimental parameters such as reaction temperature, metal salt concentration and oleic acid/oleylamine ratio. Though the as-synthesized particles were coated with oleate and were dispersible in organic solvent, their surfaces were modified using amphiphilic co-polymers composed of poly(maleic anhydride-alt-1-octadecene) and polyethylene glycol-methyl ether and made dispersible in water. Infrared spectra of the sample indicated the existence of -COOH groups on the surface for further conjugation with biomolecules for targeted cancer therapy. (C) 2010 Elsevier B.V. All rights reserved.