A Thermofluid Analysis of the Magnetic Nanoparticles Enhanced Heating Effects in Tissues Embedded with Large Blood Vessel during Magnetic Fluid Hyperthermia

Abstract

The thermal effect developed due to the heating of magnetic nanoparticles (MNPs) in presence of external magnetic field can be precisely controlled by the proper selection of magnetic absorption properties of the MNPs. The present paper deals with the numerical simulation of temperature field developed within or outside the tumor, in the presence of an external alternating magnetic field, using a thermofluidic model developed using ANSYS FLUENT5. A three-layer nonuniform tissue structure with one or two blood vessels surrounding the tumor is considered for the present simulation. The results obtained clearly suggest that the volumetric distribution pattern of MNPs within the tumor has a strong influence on the temperature field developed. The linear pattern of volumetric distribution has a strong effect over the two other types of distribution considered herein. Various other important factors like external magnetic field intensity, frequency, vascular congestion, types of MNP material, and so forth are considered to find the influence on the temperature within the tumor. Results show that proper selection of these parameters has a strong influence on the desired therapeutic temperature range and thus it is of utmost importance from the efficacy point of view of magnetic fluid hyperthermia (MFH).

Validation of a coupled electromagnetic and thermal model for estimating temperatures during magnetic nanoparticle hyperthermia

“…Such fully coupled electromagnetic and thermal models should integrate both "absorption" based eddy-current heating due to AMF-tissue interaction, 'loss (hysteresis)' based magnetic nanoparticle heating and thermoregulatory responses such as vasodilation or collapse in capillaries, and heat sink effects of larger nearby blood vessels [24][25][26][27][28]. Rigorous validation of the fully coupled electromagnetic and thermal treatment planning models are limited as only few clinical [15,17] and preclinical [29,30] AMF systems are calibrated and fully characterized.…”

Synthesis and characterization of nanometric magnetite coated by oleic acid and the surfactant CTAB

“…nm-Fe 3 O 4 , for instance, produces more heat than micrometric magnetite (μ-Fe 3 O 4 ) under an alternate magnetic field due to a larger magnetic susceptibility. In fact, this magnetic heating property of nm-Fe 3 O 4 is the basis of magnetic fluid hyperthermia for treating cancers [5][6][7]. In addition to this, the high biocompatibility of magnetite has also played a crucial role for its large use in other biomedical applications, such as in diagnostics and therapy [8].…”

Radiofrequency Remote Control of Thermolysin Activity

“…We use 6.1 nm gold coated magnetite particles covalently linked to the thermostable protease, thermolysin. The superparamagnetic 4.5 nm magnetite cores heat under radiofrequency (RF) irradiation at 17.76 MHz, as the magnetic field torques the magnetic moments and the particles relax via Neel relaxation mechanisms [20][21][22][23][24].…”