A Dense Magnetic Coil Array with Multi-locus and Multi-site Patterning

<p>· We propose multi-loci and multi-site current patterning (sequential or simultaneous) for precise, rapid and repeatable steering for improved neuronal targeting.</p><p>· Here we demonstrate these improvements by using a unique pixel cell for excitation synthesis as enabled by a three-layer dense magnetic coil array that is mapped to a hexagonal grid with cubic coordinates.</p><p>· We validate the theory with supporting simulations, experimental results and a scalable electronics design that can address a relevant range of larger coil diameters, higher power levels and topologies.</p><p><a></a></p><p>· Precise, rapid and repeatable patterns potentially offer new modalities for noninvasive neuromodulation (suprathreshold and subthreshold) and adjacent biomagnetic applications such as tumor cell membrane disruption [1], and magnetic drug delivery [2].</p>

A Dense Magnetic Coil Array with Multi-locus and Multi-site Patterning

<p>· We propose multi-loci and multi-site current patterning (sequential or simultaneous) for precise, rapid and repeatable steering for improved neuronal targeting.</p><p>· Here we demonstrate these improvements by using a unique pixel cell for excitation synthesis as enabled by a three-layer dense magnetic coil array that is mapped to a hexagonal grid with cubic coordinates.</p><p>· We validate the theory with supporting simulations, experimental results and a scalable electronics design that can address a relevant range of larger coil diameters, higher power levels and topologies.</p><p><a></a></p><p>· Precise, rapid and repeatable patterns potentially offer new modalities for noninvasive neuromodulation (suprathreshold and subthreshold) and adjacent biomagnetic applications such as tumor cell membrane disruption [1], and magnetic drug delivery [2].</p>

The Investigation of Conductivity of Magnetic Nanoparticles in the Vascular Network by DCC Method and the Effect of Forces on the Efficiency of Targeted Magnetic Drug Delivery

Purpose: Targeted magnetic drug delivery is one of the methods of cancer treatment. In this method, magnetic factors are conducted inside the body by a variable external magnetic field and deliver the drug agents to the tumor area. The present study aimed to investigate the performance of the drug magnetic conduction by using Differential Current Coil (DCC) and the effect of gravity force on it. Materials and Methods: In mathematical modeling, magnetic, hydrodynamic and gravity forces were assumed to affect the movement of magnetic nanoparticles inside the vessels. Helmholtz coils with a circular cross-section and different currents were simulated in the software environment. The trajectory of nanoparticles within the static fluid, Y-shape channel and multi-branch vascular network was calculated. The relations between the magnetic force applied on the magnetic nanoparticles and the parameters of coil flow, radius and relative permeability of the nanoparticles were investigated. Results: The magnetic flux generated in the coils was calculated and the particles moved in the direction of the magnetic gradient. The diagram of magnetophoresis force changes with the physical parameters was calculated. Particle trajectory and correct exit rate were obtained in simulated vessels. The output changes in the state of with-the-effect and without-the-effect of gravity were about 1.5 to 3%. The output changes of the correct and incorrect branches were calculated by changing the angle of the branches. Conclusion: From the approximate reduction of 2% of the correct output, it can be concluded that the effect of gravity on the conductivity of the system can be neglected. Besides, it seems that as the injection point is closer to the conduction point, the amount of the correct output will increase more.

Biomedical Applications of Biomaterials Functionalized with Magnetic Nanoparticles

The combination of magnetic nanoparticles and a biocompatible material leads to the manufacturing of a multifunctional and remotely controlled platform useful for diverse biomedical issues. If a static magnetic field is applied, a magnetic scaffold behaves like an attraction platform for magnetic carriers of growth factors, thus being a potential tool to enhance magnetic drug delivery in regenerative medicine. To translate in practice this potential application, a careful and critical description of the physics and the influence parameter is required. This chapter covers the mathematical modeling of the process and assesses the problem of establishing the influence of the drug delivery system on tissue regeneration. On the other hand, if a time-varying magnetic field is applied, the magnetic nanoparticles would dissipate heat, which can be exploited to perform local hyperthermia treatment on residual cancer cells in the bone tissue. To perform the treatment planning, it is necessary to account for the modeling of the intrinsic nonlinear nature of the heat dissipation dynamic in magnetic prosthetic implants. In this work, numeric experiments to investigate the physiopathological features of the biological system, linked to the properties of the nanocomposite magnetic material, to assess its effectiveness as therapeutic agents are presented.

Shape Anisotropic Iron Oxide-Based Magnetic Nanoparticles: Synthesis and Biomedical Applications

Research on iron oxide-based magnetic nanoparticles and their clinical use has been, so far, mainly focused on the spherical shape. However, efforts have been made to develop synthetic routes that produce different anisotropic shapes not only in magnetite nanoparticles, but also in other ferrites, as their magnetic behavior and biological activity can be improved by controlling the shape. Ferrite nanoparticles show several properties that arise from finite-size and surface effects, like high magnetization and superparamagnetism, which make them interesting for use in nanomedicine. Herein, we show recent developments on the synthesis of anisotropic ferrite nanoparticles and the importance of shape-dependent properties for biomedical applications, such as magnetic drug delivery, magnetic hyperthermia and magnetic resonance imaging. A brief discussion on toxicity of iron oxide nanoparticles is also included.