scholarly journals Magnetic Nanoparticles with High Specific Absorption Rate at Low Alternating Magnetic Field

Nano LIFE ◽  
2015 ◽  
Vol 05 (02) ◽  
pp. 1550002 ◽  
Author(s):  
K. Kekalo ◽  
I. Baker ◽  
R. Meyers ◽  
J. Shyong

This paper describes the synthesis and properties of a new type of magnetic nanoparticle (MNP) for use in the hyperthermia treatment of tumors. These particles consist of 2–4 nm crystals of gamma- Fe 2 O 3 gathered in 20–40 nm aggregates with a coating of carboxymethyl-dextran, producing a zetasize of 110–120 nm. Despite their very low saturation magnetization (1.5–6.5 emu/g), the specific absorption rate (SAR) of the nanoparticles is 22–200 W/g at applied alternating magnetic field (AMF) with strengths of 100–500 Oe at a frequency of 160 kHz.

Author(s):  
Shujuan Huang ◽  
Amit Gupta ◽  
Diana-Andra Borca-Tasciuc

Magnetic-nanoparticles cancer hyperthermia, a side effects-free, potential cancer therapy employing magnetic nanoparticle remotely heated by alternating magnetic field (AMF), is receiving considerable attention from researchers and physicians [1–3]. Specific absorption rate (SAR), which is used to quantify nanoparticles’ heat generation under the applied AMF, is defined as the thermal power per unit mass dissipated by the magnetic material [3]. SAR depends on field parameters (magnetic field strength and frequency) and material system (size and magnetic properties of nanoparticles). Accurate measurement of SAR is a critical step in enabling comparison with theoretical predictions for understanding other parameters that may affect the heat generation rate such as nanoparticle functionalization, clustering and immobilization in biological medium [4]. A main drawback is the fact that independent measurements on similar samples often provide significantly different SAR values. For example, the reported SAR of magnetite-based aqueous solution Endorem commercially available from Guerbet greatly differs among Ref. [3], [5] and [6], even when factors such as field intensity, H, and frequency, f, are taken into account.


Nanoscale ◽  
2015 ◽  
Vol 7 (39) ◽  
pp. 16470-16480 ◽  
Author(s):  
Hyun-Chul Kim ◽  
Eunjoo Kim ◽  
Sang Won Jeong ◽  
Tae-Lin Ha ◽  
Sang-Im Park ◽  
...  

The cytotoxicity of magnetic nanoparticles-conjugated polymeric micelles encapsulated with an anticancer drug on cancer cells was enhanced by the synergistic effect of heat and the rapid release of the drug under an alternating magnetic field.


NANO ◽  
2020 ◽  
Vol 15 (01) ◽  
pp. 2050015
Author(s):  
Lihan zheng ◽  
Yuanwei Chen ◽  
Ying Wang ◽  
Peng Wang ◽  
Tao Wang

Self-regulating temperature hyperthermia based on magnetic fluid with low Curie temperature is a moderately effective method for cancer treatment. The improvement of the properties of magnetic fluids is the key for application of this method. In this paper, Bi-doped LSMO magnetic nanoparticles were synthesized using a simple sol–gel method and coated by hyaluronic acid through high energy ball milling for their possible application in self-regulating temperature hyperthermia. The crystal structure, morphology, basic magnetic properties and heating properties of these nanoparticles in a high frequency magnetic field were investigated. It was found that the hyaluronic acid-coated La[Formula: see text]Sr[Formula: see text]Bi[Formula: see text]MnO3 magnetic nanoparticles, with an average particle diameter of [Formula: see text]100[Formula: see text]nm and a Curie temperature of 48∘C, possess outstanding induction heating properties. The saturation heating temperature, specific absorption rate and effective specific absorption rate are 48∘C, 117[Formula: see text]W/g and 0.27[Formula: see text]W/g[Formula: see text]kHz[Formula: see text](kA/m2), respectively.


2019 ◽  
Author(s):  
Nikolai A Usov ◽  
Ruslan A Rytov ◽  
Vasiliy A Bautin

The dynamics of magnetic nanoparticle in a viscous liquid in rotating magnetic field has been studied by means of numerical simulation and analytical calculations. In the magneto- dynamics approximation three different modes of motion of the unit magnetization vector and particle director are distinguished depending on the rotating magnetic field frequency and amplitude. The specific absorption rate of a dilute assembly of superparamagnetic nanoparticles in rotating magnetic field is calculated by solving the Landau – Lifshitz stochastic equation for unit magnetization vector and stochastic equation for particle director. At elevated frequencies an optimal range of particle diameters is found where the specific absorption rate of an assembly in rotating magnetic field has a maximum. It is shown that for magnetic hyperthermia in rotating magnetic field it is preferable to use rotating magnetic fields of moderate amplitude, H 0 = 100 Oe, in the frequency range 400-600 kHz.


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