scholarly journals Study of the effect of dipole interactions on hyperthermia heating the cluster composed of superparamagnetic nanoparticles

AIP Advances ◽  
2015 ◽  
Vol 5 (12) ◽  
pp. 127232 ◽  
Author(s):  
R. Fu ◽  
Y. Y. Yan ◽  
C. Roberts
Keyword(s):  
Superparamagnetic Nanoparticles ◽  
Dipole Interactions

Ferromagnetic resonance of superparamagnetic nanoparticles: The effect of dipole–dipole interactions

2021 ◽  
Vol 130 (11) ◽  
pp. 113902
Author(s):  
David Slay ◽  
Dongmei Cao ◽  
Eric C. Ferré ◽  
Michalis Charilaou
Keyword(s):  
Ferromagnetic Resonance ◽  
Superparamagnetic Nanoparticles ◽  
Dipole Interactions

Tuning the Magnetic Vortex State in Magnetite Nanodiscs for Remote Control of Biological Signalling

2019 ◽  
Author(s):  
Danijela Gregurec ◽  
Alexander W. Senko ◽  
Andrey Chuvilin ◽  
Pooja Reddy ◽  
Ashwin Sankararaman ◽  
...  
Keyword(s):  
Remote Control ◽  
Ion Channels ◽  
Ground State ◽  
Magnetic Particles ◽  
Colloidal Stability ◽  
Vortex State ◽  
Magnetic Vortex ◽  
Electron Holography ◽  
Dipole Interactions ◽  
Magnetite Particles

In this work, we demonstrate the application of anisotropic magnetite nanodiscs (MNDs) as transducers of torque to mechanosensory cells under weak, slowly varying magnetic fields (MFs). These MNDs possess a ground state vortex configuration of magnetic spins which affords greater colloidal stability due to eliminated dipole-dipole interactions characteristic of isotropic magnetic particles of similar size. We first predict vortex magnetization using micromagnetic stimulations in sub-micron anisotropic magnetite particles and then use electron holography to experimentally investigate the magnetization of MNDs 98–226 nm in diameter. When MNDs are coupled to MFs, they transition between vortex and in-plane magnetization allowing for the exertion of the torque on the pN scale, which is sufficient to activate mechanosensitive ion channels in cell membranes.<br>

Multifunctional Superparamagnetic Nanoparticles: From Synthesis to siRNA Delivery

2017 ◽  
Vol 23 (16) ◽  
Author(s):  
Sanam Arami ◽  
Majid Mahdavi ◽  
Mohammad Reza Rashidi ◽  
Marziyeh Fathi ◽  
Mohammad Saeid Hejazi ◽  
...  
Keyword(s):  
Sirna Delivery ◽  
Superparamagnetic Nanoparticles

scholarly journals DEER and RIDME Measurements of the Nitroxide-Spin Labelled Copper-Bound Amine Oxidase Homodimer from Arthrobacter Globiformis

2021 ◽  
Author(s):  
Hannah Russell ◽  
Rachel Stewart ◽  
Christopher Prior ◽  
Vasily S. Oganesyan ◽  
Thembaninkosi G. Gaule ◽  
...  
Keyword(s):  
Dipolar Coupling ◽  
Amine Oxidase ◽  
Spin Labels ◽  
Arthrobacter Globiformis ◽  
Copper Amine Oxidase ◽  
Dipole Interactions ◽  
Nitroxide Spin Labels ◽  
Double Electron Electron Resonance ◽  
Dipolar Modulation ◽  
Paramagnetic Centres

AbstractIn the study of biological structures, pulse dipolar spectroscopy (PDS) is used to elucidate spin–spin distances at nanometre-scale by measuring dipole–dipole interactions between paramagnetic centres. The PDS methods of Double Electron Electron Resonance (DEER) and Relaxation Induced Dipolar Modulation Enhancement (RIDME) are employed, and their results compared, for the measurement of the dipolar coupling between nitroxide spin labels and copper-II (Cu(II)) paramagnetic centres within the copper amine oxidase from Arthrobacter globiformis (AGAO). The distance distribution results obtained indicate that two distinct distances can be measured, with the longer of these at c.a. 5 nm. Conditions for optimising the RIDME experiment such that it may outperform DEER for these long distances are discussed. Modelling methods are used to show that the distances obtained after data analysis are consistent with the structure of AGAO.

scholarly journals Concentration-dependent oscillation of specific loss power in magnetic nanofluid hyperthermia

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ji-wook Kim ◽  
Jie Wang ◽  
Hyungsub Kim ◽  
Seongtae Bae
Keyword(s):  
Magnetic Dipole ◽  
Critical Role ◽  
Dipole Interaction ◽  
Superparamagnetic Nanoparticles ◽  
Physical Reason ◽  
Strong Concentration ◽  
Magnetic Nanofluid ◽  
Specific Loss ◽  
Specific Loss Power ◽  
Magnetic Nanofluid Hyperthermia

AbstractMagnetic dipole coupling between the colloidal superparamagnetic nanoparticles (SPNPs) depending on the concentration has been paid significant attention due to its critical role in characterizing the Specific Loss Power (SLP) in magnetic nanofluid hyperthermia (MNFH). However, despite immense efforts, the physical mechanism of concentration-dependent SLP change behavior is still poorly understood and some contradictory results have been recently reported. Here, we first report that the SLP of SPNP MNFH agent shows strong concentration-dependent oscillation behavior. According to the experimentally and theoretically analyzed results, the energy competition among the magnetic dipole interaction energy, magnetic potential energy, and exchange energy, was revealed as the main physical reason for the oscillation behavior. Empirically demonstrated new finding and physically established model on the concentration-dependent SLP oscillation behavior is expected to provide biomedically crucial information in determining the critical dose of an agent for clinically safe and highly efficient MNFH in cancer clinics.

scholarly journals Influence of size polydispersity on magnetic field tunable structures in magnetic nanofluids containing superparamagnetic nanoparticles.

2021 ◽  
Author(s):  
Dillip Kumar Mohapatra ◽  
Philip James Camp ◽  
John Philip
Keyword(s):  
Magnetic Field ◽  
Particle Size ◽  
Light Scattering ◽  
Optical Microscopy ◽  
Brownian Dynamics ◽  
Phase Contrast ◽  
Superparamagnetic Nanoparticles ◽  
Magnetic Nanofluids ◽  
Dynamics Simulations ◽  
Brownian Dynamics Simulations

We probe the influence of particle size polydispersity on field-induced structures and structural transitions in magnetic fluids (ferrofluids) using phase contrast optical microscopy, light scattering and Brownian dynamics simulations. Three...

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