MISiS, MEPhI, IZMI RAS: Technology for obtaining pure magnetite nanoparticles for magnetic hyperthermia

The main articles are:

• Magnetic hyperthermia
• Nanoparticles in medicine
• Cancer treatment

2023: Obtaining the purest nanoparticles for magnetic hyperthermia

Scientists of NITU MISIS, NRNU MEPhI and IZMI RAS for the first time in the world received the purest nanoparticles for a progressive method of treating cancer - magnetic hyperthermia. This was announced to Zdrav.Expert on July 31, 2023 by representatives of the University of Science and Technology MISIS.

As they explained, a feature of the technology is to achieve an ideal crystal structure, a uniform phase composition, a chemically pure surface with the complete inheritance of the magnetic properties of the original macro sample. Substance is obtained by economical method - destruction of initial pure magnetite powder in viscous liquid at collapse of cavitation bubbles on their surface. The experimental installation was developed at NUST MISIS and manufactured entirely from domestic components.

Russian scientists for the first time in the world received the purest nanoparticles to fight cancer

According to scientists, magnetic hyperthermia plays an increasingly important role in the treatment of cancer, especially in cases of significant restrictions on the use of surgery and drug exposure, for example, in the therapy of brain neuroblastoma. Nanoscale magnetic particles are introduced into area of cancer tumor by invasive or non-invasive methods, which under action of alternating magnetic field heat surrounding area of neoplasm to 40-44 ° C, causing its necrosis, apoptosis or increased susceptibility to chemo- and radiation therapy.

As is known, commercially available magnetite nanoparticles for hyperthermia are produced by chemical methods or by gas phase reduction (CVD), which often leads to heterogeneities in the properties of the resulting substance. As a result, chemically synthesized and CVD magnetite nanoparticles often have a polycrystalline structure, as well as various inclusions and phases, which reduces saturation magnetization due to the so-called magnetic dead layer on the surface of the particles and, as a result, impairs heating capacity.

"A promising method of ultrasonic mechanical-cavitation destruction makes it possible to obtain homogeneous magnetite nanoparticles with an ideal crystal structure of the original macroscopic sample or powder, with a chemically pure surface and a high saturation magnetization of 92 emu/g, which is close to the theoretical value for pure magnetite," said the author of the study, Ph.D. N. Vasily Bautin, Associate Professor of the Department of Steel Metallurgy, New Production Technologies and Metal Protection NUST MISIS. You can get acquainted with the technology in detail in the scientific journal Ceramics International (Q1).

MISIS also drew attention to the fact that the specific absorption power of magnetic nanoparticles after their introduction into the biological medium is usually significantly reduced, to values ​ ​ less than 200 W/g. This is due to the magnetic-dipole interaction in the ensemble of magnetic nanoparticles forming dense clusters.

"We experimentally proved that if the alternating magnetic field is directed along the axis of the cluster orientation, the value of the specific power increases 4 times and reaches 600 W/g at relatively small amplitudes and the frequency of the alternating magnetic field," emphasized the co-author of the study Nikolai Usov, Ph.D., V.N. Department of Steel Metallurgy, New Production Technologies and Metal Protection, NITU MISIS, Institute of Terrestrial Magnetism, Ionosphere and Radio Wave Propagation named after N.V. Pushkov of the Russian Academy of Sciences (IZMI RAS).

This means that the therapeutic effect can be realized by introducing fewer nanoparticles and by softer exposure of the human body to an alternating magnetic field. Therefore, with the further use of these magnetic nanoparticles in the treatment of cancer tumors, the destruction of malignant neoplasms will be safer and more accessible, scientists found out.

Further implementation of research and production of particles is planned together with the scientific division of Rosatom State Corporation - Science and Innovation JSC and Moscow State Medical University named after I.M. Sechenov of the Ministry of Health of Russia.