Ardu, A.

Cannas, C.

Ennas, G.

Innocenti, C.

Mameli, V.

Musinu, A.

Niznansky, D.

Peddis, D.

Sangregorio, C.

Thanh, Nguyen T. K.

V. Mameli

A. Musinu

A. Ardu

G. Ennas

D. Peddis

D. Niznansky

C. Sangregorio

C. Innocenti

Nguyen T. K. Thanh

C. Cannas

Archivio istituzionale della ricerca - Università di Cagliari

Atlas of Scienceanother view on sciencehttp://atlasofscience.orgCobalt ferrite nanoparticles as nanoheaters to treat cancerEnhancing the tumours temperature to 41-46 °C represents an oncological therapy known as moderate hyperthermia. To selectively heat up cancer cells, avoiding any damage of the healthytissues, magnetic nanoparticles (with sizes in the range 10-9-10-7 m) stably dispersed in an water-based fluid (ferrofluid) can be injected in the body and used as nanoheaters once subjected to anexternal alternate magnetic field. Indeed, magnetic nanoparticles are able to release heatdepending on the way they respond to the external magnetic field. A proper design of thesenanoheaters should be therefore based on a proper optimisation of their magnetism in order to limitthe amount of exogenous material to inject in the human body. Among the different magneticmaterials, some iron oxides, known as spinel ferrites, are ideal systems because their magneticproperties can be strictly controlled through their chemical composition, their crystalline structure(i.e. the relative arrangement of the ions in an ordered and periodic structure), the size and shapeof the nanoparticles, the capping molecules used to stabilise their aqueous dispersion, etc.Unfortunately, during the production of the nanoparticles many features can change at the sametime (e.g., composition and particle size, etc.) and understanding how each single parameteraffects the magnetic properties and the heating ability can be challenging.Fig. 1. The possibility to finely control the features of cobalt ferrite nanoparticles together with anaccurate characterisation pave the way to design new promising nanoheaters for Magnetic FluidHyperthermia.                               1 / 3Atlas of Scienceanother view on sciencehttp://atlasofscience.orgIn this framework, cobalt ferrite, a mixed spinel ferrite with chemical formula CoFe2O4, was chosenas a starting material being characterised by good magnetic properties. Moreover, other systemswere produced by substituting part of the cobalt ions by non-magnetic zinc ones (mixed cobalt-zincferrites) keeping all the other features similar (Fig. 1), with the aim of (i) lowering the intrinsictoxicity of cobalt ions and (ii) tuning the magnetic properties.Our study shows that, within the adopted experimental conditions, pure cobalt ferrite nanoparticlesare more efficient in the heat release than the zinc-substituted ones due to the critical role of the magnetic anisotropy, a magnetic property associated with the existence of preferential directionsfor the spontaneous magnetisation process.  The necessity of a magnetic characterisation by usingan alternate magnetic field, that better simulate the application condition, instead of a static one isstraightforward, together with the deep and detailed investigation of the magnetic behaviour of thesamples at low temperature (5 K) (Magnetometry and M?ssbauer Spectroscopy). The magneticbehaviour was explained in terms of the positions occupied by the metal ions (Co2+, Zn2+, Fe3+)within the crystalline structure. Is in fact the distribution of the cations among these sites that affectthe magnetic properties.Finally, this work demonstrates how such systematic studies based on a multitechnique approach(X-ray Diffraction, Transmission Electron Microscopy, Thermal analysis, ICP-OES, Dynamic LightScattering, Infrared Spectroscopy, DC and AC magnetometry, M?ssbauer Spectroscopy) arecrucial for a proper understanding of the role of the different parameters in the heating ability of themagnetic nanoparticles and, therefore, for a suitable design of the next generation of nanoheaters.V. Mameli 1,2, A. Musinu 1,2, A. Ardu 1,2,3, G. Ennas 1,2, D. Peddis 4, D. Niznansky 5, C.Sangregorio 2,6, C. Innocenti 2,7, Nguyen T. K. Thanh 8,9 and C. Cannas 1,2,31Department of Chemical and Geological Sciences, University of Cagliari, Monserrato, CA, Italy 2Consorzio Interuniversitario Nazionale per la Scienza e Tecnologia dei Materiali (INSTM), Italy 3Consorzio AUSI, CREATE, Palazzo Bellavista Monteponi, Iglesias, Italy 4Istituto di Struttura della Materia, Consiglio Nazionale delle Ricerche (ISM-CNR), Italy 5Department of Inorganic Chemistry, Charles University of Prague, Czech Republic 6Istituto di Chimica dei Composti OrganoMetallici, Consiglio Nazionale delle Ricerche (ICCOM-CNR), Sesto Fiorentino, Italy 7LAboratorio di Magnetismo Molecolare (LA.M.M), Department of Chemistry, University ofFlorence, Sesto Fiorentino, Italy 8Biophysics Group, Department of Physics and Astronomy, University College London, GowerStreet, London, UK 9UCL Healthcare Biomagnetic and Nanomaterials Laboratory, 21 Albemarle Street, London, UK Publication                               2 / 3Atlas of Scienceanother view on sciencehttp://atlasofscience.orgStudying the effect of Zn-substitution on the magnetic and hyperthermic properties of cobalt ferritenanoparticles.Mameli V, Musinu A, Ardu A, Ennas G, Peddis D, Niznansky D, Sangregorio C, Innocenti C, ThanhNT, Cannas C.Nanoscale. 2016 May 21Powered by TCPDF (www.tcpdf.org)                               3 / 3

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Cobalt ferrite nanoparticles as nanoheaters to treat cancer

Cobalt ferrite nanoparticles as nanoheaters to treat cancer

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