scholarly journals A Simulation Study on the Specific Loss Power in Magnetic Hyperthermia in the Presence of a Static Magnetic Field

2016 ◽  
Vol 06 (12) ◽  
pp. 839-851 ◽  
Author(s):  
Kenya Murase
Keyword(s):  
Magnetic Field ◽  
Static Magnetic Field ◽  
Simulation Study ◽  
Magnetic Hyperthermia ◽  
Specific Loss ◽  
Specific Loss Power

scholarly journals Specific Loss Power of Co/Li/Zn-Mixed Ferrite Powders for Magnetic Hyperthermia

Sensors ◽  
2020 ◽  
Vol 20 (7) ◽  
pp. 2151
Author(s):  
Gabriele Barrera ◽  
Marco Coisson ◽  
Federica Celegato ◽  
Luca Martino ◽  
Priyanka Tiwari ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Magnetic Properties ◽  
Cation Distribution ◽  
Biomedical Applications ◽  
Magnetic Measurements ◽  
Magnetic Hyperthermia ◽  
Alternating Magnetic Field ◽  
Specific Loss ◽  
Specific Loss Power ◽  
Auto Combustion

An important research effort on the design of the magnetic particles is increasingly required to optimize the heat generation in biomedical applications, such as magnetic hyperthermia and heat-assisted drug release, considering the severe restrictions for the human body’s exposure to an alternating magnetic field. Magnetic nanoparticles, considered in a broad sense as passive sensors, show the ability to detect an alternating magnetic field and to transduce it into a localized increase of temperature. In this context, the high biocompatibility, easy synthesis procedure and easily tunable magnetic properties of ferrite powders make them ideal candidates. In particular, the tailoring of their chemical composition and cation distribution allows the control of their magnetic properties, tuning them towards the strict demands of these heat-assisted biomedical applications. In this work, Co0.76Zn0.24Fe2O4, Li0.375Zn0.25Fe2.375O4 and ZnFe2O4 mixed-structure ferrite powders were synthesized in a ‘dry gel’ form by a sol-gel auto-combustion method. Their microstructural properties and cation distribution were obtained by X-ray diffraction characterization. Static and dynamic magnetic measurements were performed revealing the connection between the cation distribution and magnetic behavior. Particular attention was focused on the effect of Co2+ and Li+ ions on the magnetic properties at a magnetic field amplitude and the frequency values according to the practical demands of heat-assisted biomedical applications. In this context, the specific loss power (SLP) values were evaluated by ac-hysteresis losses and thermometric measurements at selected values of the dynamic magnetic fields.

scholarly journals Optimization Study on Specific Loss Power in Superparamagnetic Hyperthermia with Magnetite Nanoparticles for High Efficiency in Alternative Cancer Therapy

Nanomaterials ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 40
Author(s):  
Costica Caizer
Keyword(s):  
Magnetic Field ◽  
Magnetic Nanoparticles ◽  
Cancer Therapy ◽  
Tumor Cells ◽  
Heating Temperature ◽  
Magnetic Hyperthermia ◽  
Optimal Conditions ◽  
Specific Loss ◽  
Specific Loss Power ◽  
The Magnetic Field

The cancer therapy with the lowest possible toxicity is today an issue that raises major difficulties in treating malignant tumors because chemo- and radiotherapy currently used in this field have a high degree of toxicity and in many cases are ineffective. Therefore, alternative solutions are rapidly being sought in cancer therapy, in order to increase efficacy and a reduce or even eliminate toxicity to the body. One of the alternative methods that researchers believe may be the method of the future in cancer therapy is superparamagnetic hyperthermia (SPMHT), because it can be effective in completely destroying tumors while maintaining low toxicity or even without toxicity on the healthy tissues. Superparamagnetic hyperthermia uses the natural thermal effect in the destruction of cancer cells, obtained as a result of the phenomenon of superparamagnetic relaxation of the magnetic nanoparticles (SPMNPs) introduced into the tumor; SPMNPs can heat the cancer cells to 42–43 °C under the action of an external alternating magnetic field with frequency in the range of hundreds of kHz. However, the effectiveness of this alternative method depends very much on finding the optimal conditions in which this method must be applied during the treatment of cancer. In addition to the type of magnetic nanoparticles and the biocompatibility with the biological tissue or nanoparticles biofunctionalization that must be appropriate for the intended purpose a key parameter is the size of the nanoparticles. Also, establishing the appropriate parameters for the external alternating magnetic field (AMF), respectively the amplitude and frequency of the magnetic field are very important in the efficiency and effectiveness of the magnetic hyperthermia method. This paper presents a 3D computational study on specific loss power (Ps) and heating temperature (ΔT) which allows establishing the optimal conditions that lead to efficient heating of Fe3O4 nanoparticles, which were found to be the most suitable for use in superparamagnetic hyperthermia (SPMHT), as a non-invasive and alternative technique to chemo- and radiotherapy. The size (diameter) of the nanoparticles (D), the amplitude of the magnetic field (H) and the frequency (f) of AMF were established in order to obtain maximum efficiency in SPMHT and rapid heating of magnetic nanoparticles at the required temperature of 42–43 °C for irreversible destruction of tumors, without affecting healthy tissues. Also, an analysis on the amplitude of the AMF is presented, and how its amplitude influences the power loss and, implicitly, the heating temperature, observables necessary in SPMHT for the efficient destruction of tumor cells. Following our 3D study, we found for Fe3O4 nanoparticles the optimal diameter of ~16 nm, the optimal range for the amplitude of the magnetic field of 10–25 kA/m and the optimal frequency within the biologically permissible limit in the range of 200–500 kHz. Under the optimal conditions determined for the nanoparticle diameter of 16.3 nm, the magnetic field of 15 kA/m and the frequency of 334 kHz, the magnetite nanoparticles can be quickly heated to obtain the maximum hyperthermic effect on the tumor cells: in only 4.1–4.3 s the temperature reaches 42–43 °C, required in magnetic hyperthermia, with major benefits in practical application in vitro and in vivo, and later in clinical trials.

scholarly journals Role of zinc substitution in magnetic hyperthermia properties of magnetite nanoparticles: interplay between intrinsic properties and dipolar interactions

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Yaser Hadadian ◽  
Ana Paula Ramos ◽  
Theo Z. Pavan
Keyword(s):  
Magnetic Nanoparticles ◽  
Magnetite Nanoparticles ◽  
Linear Response Theory ◽  
Magnetic Hyperthermia ◽  
Superior Performance ◽  
Dipolar Interactions ◽  
Intrinsic Properties ◽  
Specific Loss ◽  
Heating Efficiency ◽  
Specific Loss Power

AbstractOptimizing the intrinsic properties of magnetic nanoparticles for magnetic hyperthermia is of considerable concern. In addition, the heating efficiency of the nanoparticles can be substantially influenced by dipolar interactions. Since adequate control of the intrinsic properties of magnetic nanoparticles is not straightforward, experimentally studying the complex interplay between these properties and dipolar interactions affecting the specific loss power can be challenging. Substituting zinc in magnetite structure is considered as an elegant approach to tune its properties. Here, we present experimental and numerical simulation results of magnetic hyperthermia studies using a series of zinc-substituted magnetite nanoparticles (ZnxFe1-xFe2O4, x = 0.0, 0.1, 0.2, 0.3 and 0.4). All experiments were conducted in linear regime and the results were inferred based on the numerical simulations conducted in the framework of the linear response theory. The results showed that depending on the nanoparticles intrinsic properties, interparticle interactions can have different effects on the specific loss power. When dipolar interactions were strong enough to affect the heating efficiency, the parameter σ = KeffV/kBT (Keff is the effective anisotropy and V the volume of the particles) determined the type of the effect. Finally, the sample x = 0.1 showed a superior performance with a relatively high intrinsic loss power 5.4 nHm2kg−1.

Numerical Simulation Study for the Effect of the Strength and the Direction of a Static Magnetic Field on the Transient Double-Diffusive Flow in Liquid Phase during an Alloy Solidification

2010 ◽  
Vol 297-301 ◽  
pp. 97-104 ◽  
Author(s):  
Farid Mechighel ◽  
Bernard Pateyron ◽  
Mahfoud Kadja ◽  
Mohammed El Ganaoui ◽  
S. Dost
Keyword(s):  
Magnetic Field ◽  
Numerical Simulation ◽  
Static Magnetic Field ◽  
Simulation Study ◽  
Solidification Process ◽  
Magnetic Field Effects ◽  
Charge Balance ◽  
Diffusive Flow ◽  
Volume Method ◽  
Double Diffusive

A numerical simulation study has been carried out to examine the effect of a static magnetic field on the solidification process of an alloy. A mathematical model, based on the continuum model, was developed for the computation of a transient double-diffusive fluid flow under Lorentz body force. The model includes conservation of mass and momentum, heat, species and electrical charge balance equations. The simulation domain was selected as a cavity filled with a metallic alloy and differentially heated, which may be taken as a Bridgman model domain used in the crystal growth process. The solution is carried out by using a Finite Volume Method. Study of the direction and the intensity of the applied magnetic field effects on stabilizing the double diffusive flow field were also carried out. Simulation results indicate that the use of a static, magnetic field in this growth setup is effective in suppressing natural convection in the solution.

A Numerical Simulation Study on the Effects of Crucible Rotation and Magnetic Fields in Growth of SiGe by the Traveling Heater Method

2011 ◽  
Vol 134 (1) ◽  
Author(s):  
Youhei Takagi ◽  
Yasunori Okano ◽  
Sadik Dost
Keyword(s):  
Magnetic Field ◽  
Numerical Simulation ◽  
Static Magnetic Field ◽  
Simulation Study ◽  
Concentration Field ◽  
Magnetic Field Direction ◽  
Simultaneous Application ◽  
Rotation Rates ◽  
Traveling Heater Method ◽  
Crucible Rotation

A numerical simulation study was carried out to shed light on the effects of applied crucible rotation and static magnetic field during the traveling heater method growth of bulk SiGe single crystals. The simulation results show that the application of crucible rotation weakens the radial silicon concentration gradient due to the effect of centrifugal force. The effects of applied static magnetic field direction and strength on the concentration field in the melt were also studied. It was found that the simultaneous application of crucible rotation and static magnetic field is best to grow large crystals with uniform composition. An optimum combination of crucible rotation rates and applied magnetic field strengths is determined.

scholarly journals Control of the temperature rise in magnetic hyperthermia with use of an external static magnetic field

2013 ◽  
Vol 29 (6) ◽  
pp. 624-630 ◽  
Author(s):  
Kenya Murase ◽  
Hiroshige Takata ◽  
Yuki Takeuchi ◽  
Shigeyoshi Saito
Keyword(s):  
Magnetic Field ◽  
Static Magnetic Field ◽  
Temperature Rise ◽  
Magnetic Hyperthermia ◽  
External Static Magnetic Field
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