Preparation of magnetite aqueous dispersion for magnetic fluid hyperthermia

An aqueous magnetic suspension was prepared by dispersing amphiphilic co-polymer-coated monodispersed 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.

Research Highlights
► Preparation of magnetite nanoparticles suitable for in vivo magnetic fluid hyperthermia.
► Thermal decomposition of Fe(acac)3 in a mixture of oleic acid and oleylamine.
► Monodispersed magnetite particles with average sizes varying between 5 and 12 nm.
► Modification of the hydrophobic particle surface with amphiphilic co-polymers.
► These surface modified particles have carboxyl groups and polyethylene glycol.