Computational Study of Magnetic Particle Motion inside the Nasal Cavity under the Impact of an External Magnetic Field for Biomedical Applications.

The blood−brain barrier is a highly selective semipermeable border that separates blood circulation from the brain and hinders the accumulation of substances in the central nervous system. Hence, a treatment plan aiming to combat neurodegenerative diseases may be restricted. The exploitation of the nose−brain pathway could be a promising bypass method.

Numerical Simulation of Temperature Variations during the Application of Safety Protocols in Magnetic Particle Hyperthermia.

Unavoidably, magnetic particle hyperthermia is limited by the unwanted heating of the neighboring healthy tissues, due to the generation of eddy currents. Eddy currents naturally occur, due to the applied alternating magnetic field, which is used to excite the nanoparticles in the tumor and, therefore, restrict treatment efficiency in clinical application. In this work, we present two simply applicable methods for reducing the heating of healthy tissues by simultaneously keeping the heating of cancer tissue, due to magnetic nanoparticles, at an adequate level.

Hydrotalcite-Embedded Magnetite Nanoparticles for Hyperthermia-Triggered Chemotherapy.

A magnetic nanocomposite, consisting of FeO nanoparticles embedded into a Mg/Al layered double hydroxide (LDH) matrix, was developed for cancer multimodal therapy, based on the combination of local magnetic hyperthermia and thermally induced drug delivery. The synthesis procedure involves the sequential hydrolysis of iron salts (Fe, Fe) and Mg/Al nitrates in a carbonate-rich mild alkaline environment followed by the loading of 5-fluorouracil, an anionic anticancer drug, in the interlayer LDH space. Magnetite nanoparticles with a diameter around 30 nm, dispersed in water, constitute the hyperthermia-active phase able to generate a specific loss of power of around 500 W/g-Fe in an alternating current (AC) magnetic field of 24 kA/m and 300 kHz as determined by AC magnetometry and calorimetric measurements.

Magneto-fluorescent nanocomposites: experimental and theoretical linkage for the optimization of magnetic hyperthermia.

Magneto-fluorescent nanocomposites have been recognized as an emerging class of materials displaying great potential for improved magnetic hyperthermia assisted by optical imaging. In this study, we have designed a series of hybrid composites that consist of zinc doped ZnFeO ferrites functionalized by polyethylene-glycol (PEG8000) and an orange-emitting platinum complex [Pt(phen)Cl]. Experimental and theoretical studies on the optimization of their magnetically-mediated heating properties were conducted.

Mitigation of magnetic particle hyperthermia side effects by magnetic field controls.

In magnetic particle hyperthermia, a promising least-invasive cancer treatment, malignant regions in proximity with magnetic nanoparticles undergo heat stress, while unavoidably surrounding healthy tissues may also suffer from heat either directly or indirectly by the induced eddy currents, due to the developed electric fields as well. Here, we propose a facile upgrade of a typical magnetic particle hyperthermia protocol, to selectively mitigate eddy currents' heating without compromising the beneficial role of heating in malignant regions. The key idea is to apply the external magnetic field intermittently (in an ON/OFF pulse mode), instead of the continuous field mode typically applied.

Improvement of Magnetic Particle Hyperthermia: Healthy Tissues Sparing by Reduction in Eddy Currents.

Attenuation of the unwanted heating of normal tissues due to eddy currents presents a major challenge in magnetic particle hyperthermia for cancer treatment. Eddy currents are a direct consequence of the applied alternating magnetic field, which is used to excite the nanoparticles in the tumor and have been shown to limit treatment efficacy in clinical trials. To overcome these challenges, this paper presents simple, clinically applicable, numerical approaches which reduce the temperature increase due to eddy currents in normal tissue and simultaneously retain magnetic nanoparticles heating efficiency within the tumor.

Spatial focusing of magnetic particle hyperthermia.

Magnetic particle hyperthermia is a promising cancer therapy, but a typical constraint of its applicability is localizing heat solely to malignant regions sparing healthy surrounding tissues. By simultaneous application of a constant magnetic field together with the hyperthermia inducing alternating magnetic field, heating focus may be confined to smaller regions in a tunable manner. The main objective of this work is to evaluate the focusing parameters, by adequate selection of magnetic nanoparticles and field conditions, and explore spatially focused magnetic particle hyperthermia efficiency in tissue phantom systems comprising agarose gel and magnetic nanoparticles.

Effect of low frequency magnetic fields on the growth of MNP-treated HT29 colon cancer cells.

Recent investigations have attempted to understand and exploit the impact of magnetic field-actuated internalized magnetic nanoparticles (MNPs) on the proliferation rate of cancer cells. Due to the complexity of the parameters governing magnetic field-exposure though, individual studies to date have raised contradictory results. In our approach we performed a comparative analysis of key parameters related to the cell exposure of cancer cells to magnetic field-actuated MNPs, and to the magnetic field, in order to better understand the factors affecting cellular responses to magnetic field-stimulated MNPs.

Arrangement at the nanoscale: Effect on magnetic particle hyperthermia.

In this work, we present the arrangement of FeO magnetic nanoparticles into 3D linear chains and its effect on magnetic particle hyperthermia efficiency. The alignment has been performed under a 40 mT magnetic field in an agarose gel matrix. Two different sizes of magnetite nanoparticles, 10 and 40 nm, have been examined, exhibiting room temperature superparamagnetic and ferromagnetic behavior, in terms of DC magnetic field, respectively.