Disk-shaped magnetic particles for cancer therapy

Abstract

Magnetic disks are a new generation of nanoparticles with outstanding properties to face biomedical challenges as a cancer treatment. The key features of their suitability are the ability of rotation (torque), the high dispersion capability, and the easy manipulation under low magnetic fields. These properties make disk-shaped particles ideal magnetomechanical actuators to damage cancer cell integrity, deliver antitumor drugs, generate heat (magnetic hyperthermia), or separate cancer cells for early detection. Since the experimental demonstration of the capability of destroying brain cancer cells by the force exerted from rotating Ni80Fe20 microdisks, important advances have been reported on disks composed of different magnetic materials and dimensions. Here, we present the evolution of a decade-old research field by combining the discussion of in vitro experiments available in the literature with our most recent results. More importantly, we compare the torque and dispersion capability of each type of magnetic disk in order to promote the investigation toward the most efficient magnetomechanical actuator to destroy cancer cells.

Cancer treatment by magneto-mechanical effect of particles, a review

“…TMMEP method is reported as appropriate for sparing the surrounding healthy cells, since the magnetomechanical vibration applied on or within the targeted cancer cells remains highly local, in contrast with methods using heat which tends to diffuse into the neighboring tissues. 22,24 Although these rst trials of TMMEP treatments on cancer cells have yet to be deepened, the method could allow great improvements in future cancer treatments, and a hope for treating cancer with very poor prognosis as glioblastoma, for instance. Investigations on cancer cells destruction through magnetically actuated microparticles vibrating at low frequency, are nally of great interest for future cancer therapy, while remaining a big challenge.…”

“…Rotatingor more generally variablemagnetic elds, spatially uniform, are thus used to induce continuous rotation or vibration of the particles in TMMEP. In this approach requiring effective magnetic torque, highly anisotropic particles are oen preferred, such as for instance magnetic disks with "magnetic shape anisotropy", 24 or with "perpendicular magnetic anisotropy". 27 Subjected to the variable magnetic eld, the particle thus transfers its mechanical energy to its environment, on Fig.…”

“…Iron oxides such as magnetite (Fe 3 O 4 ) or maghemite (g-Fe 2 O 3 ) are therefore very good candidates being usually chosen for their biocompatibility, although in some respects they may exhibit non-negligible cytotoxicity. 24,53,54 In particular, naked iron oxide nanoparticles are known to induce reactive oxygen species (ROS), considered as one of the main mechanisms of nanotoxicity, as investigated in Ling and Hyeon, 2013, 53 and Goiriena-Goikoetxea et al, 2020. 24 However, this toxicity of iron oxide nanoparticles is greatly reduced when they are enveloped in a biocompatible layer, based either on inorganic shells, such as for example gold, silica or tantalum coatings, or on a large variety of biocompatible organic shells, depending on the nanoparticle core type and the intended applications.…”

“…Biological mechanisms leading to the particles engulfment by phagocytic cells, which occur mainly in organs such as the liver, spleen and lungs, 63,66 highly contribute to eliminate particles from the blood circulation, preventing them to be delivered to the tumor site. 24,66 According to their size, particles may also be eliminated by the kidneys, lymph nodes and skin. Because of this systematic loss of particles, approaches utilizing a systemic administration of particles still require to be improved for clinical applications.…”

From Micromagnetic to In Silico Modeling of Magnetic Nanodisks for Hyperthermia Applications

“…In the last two decades, different types of magnetic nanostructures, like nanodisks that exhibit vortex configuration, have been investigated for potential use in magnetic recording, magnetologic devices, and spin-torque nano-oscillators. [1][2][3][4][5] More recently, attention has been paid to biomedical applications related to nanomedicine therapeutics and diagnostics, also with the exploration of non-spherical micro-and nanoparticles, [6][7][8][9][10][11] as an DOI: 10.1002/adts.202100013 alternative to the typically used superparamagnetic iron oxide nanoparticles (SPIONs). [12,13] As an example, magnetic nano/microdisks have been proposed as efficient magneto-mechanical actuators to destroy cancer cells, exploiting their ability to rotate under the action of low frequency magnetic fields (f = 10-20 Hz).…”