Correlation Between the Viscosity and the Response to an Alternating Magnetic Field of Magnetite Nanoparticles

M L MOJICA PISCIOTTI ; R D ZYSLER; ENIO LIMA JR.; M VÁSQUEZ MANSILLA

Paris

Conferencia; International Conference on Nanoscience + Technology ICN+T2012; 2012

In nanomedicine, one of themost promising procedures involving diagnosis and treatment of cancer is the hyperthermia. ￿is technique consists of making superparamagnetic nanoparticles (NPs) are absorbed by cancer cells, thus when they interact with an AC magnetic field, the nanoparticles absorb energy of the field and then convert it to thermal energy. ￿is leads to an aggressive increase in temperature of cancer cells causing cell death.[1] One of the basic objectives to guarantee the effectiveness of hyperthermia is focused on the development of magnetic nanoparticles whose surface can be modified to ensure their uptake by the tumor cells. Likewise, some speci￿c environmental conditions must be analyzed too.This is the case of the microviscosity of the local environment.[2] For this purpose, in this work we have studied the correlation between the heating response of magnetite (Fe3O4) NPs with different sizes and viscosity of the liquid in which they are suspend. We have synthetized the NPs through themethod of high temperature decomposition of Fe(acac)3 and we studied their morphological and magnetic properties, checking that the synthesis method offers an optimum control over size and dispersion. Later on we coated the NPs with different surfactants and suspend them in aqueous media in order to measure the specific absortion rate (SAR). We found a strong dependence between the viscosity of the NPs in the solvent and the heating response of them, which shows clearly the importance of the surrounding medium so as to maximize heat dissipation. [1] R. Hergt, S. Dutz, R. Müller, and M. Zeisberger, ?Magnetic Particle Hyperthermia: Nanoparticle Magnetism and Materials Development for Cancer Therapy?, J. Phys.: Condens. Matter 18, S2919 (2006). [2] H. Mamiya and B. Jeyadevan, ?Hyperthermic Effects of Dissipative Structures of Magnetic Nanoparticles in Large AlternatingMagnetic Fields?, Sci. Rep. 1, 157 (2011).