Experimental determination of the frequency and field dependence of Specific Loss Power in Magnetic Fluid Hyperthermia
Articolo
Data di Pubblicazione:
2017
Citazione:
Experimental determination of the frequency and field dependence of Specific Loss Power in Magnetic Fluid Hyperthermia / M. Cobianchi, A. Guerrini, M. Avolio, C. Innocenti, M. Corti, P. Arosio, F. Orsini, C. Sangregorio, A. Lascialfari. - In: JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS. - ISSN 0304-8853. - 444(2017 Dec 15), pp. 154-160. [10.1016/j.jmmm.2017.08.014]
Abstract:
Magnetic nanoparticles are promising systems for biomedical applications and in particular for Magnetic Fluid Hyperthermia, a therapy that utilizes the heat released by such systems to damage tumor cells. We present an experimental study of the physical properties that influences the capability of heat release, i.e. the Specific Loss Power, SLP, of three biocompatible ferrofluid samples having a magnetic core of maghemite with different diameter d = 10.2, 14.6 and 19.7 nm. The SLP was measured as a function of frequency f and intensity H of the applied alternating magnetic field, and it turned out to depend on the core diameter, as expected. The results allowed us to highlight experimentally that the physical mechanism responsible for the heating is size-dependent and to establish, at applied constant frequency, the phenomenological functional relationship SLP = c.H-x, with 2 <= x<3 for all samples. The x-value depends on sample size and field frequency, here chosen in the typical range of operating magnetic hyperthermia devices. For the smallest sample, the effective relaxation time tau(eff) approximate to 19.5 ns obtained from SLP data is in agreement with the value estimated from magnetization data, thus confirming the validity of the Linear Response Theory model for this system at properly chosen field intensity and frequency.
Tipologia IRIS:
01 - Articolo su periodico
Keywords:
magnetic fluid hyperthermia; magnetic nanoparticles; specific loss power; superparamagnetism; electronic, optical and magnetic materials; condensed matter physics
Elenco autori:
M. Cobianchi, A. Guerrini, M. Avolio, C. Innocenti, M. Corti, P. Arosio, F. Orsini, C. Sangregorio, A. Lascialfari
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