Anatoly A. Kuznetsov

Evaluation of ferromagnetic fluids and suspensions for the site-specific radiofrequency-induced hyperthermia of MX11 sarcoma cells in vitro

Seventeen different ferromagnetic fluids and suspensions were prepared and evaluated for application in radiofrequency-induced hyperthermia. Specific power absorption rates were measured at 0.88 MHz to range from 0 to 240 W per gram of iron for different preparations. Survival of MX11 cells mixed with ferrofluids and subjected to radiofrequency was much lower than with RF without ferrofluid or ferrofluid alone.

New ferro-carbon adsorbents for magnetically guided transport of anti-cancer drugs

Abstract The plasmachemical technology of iron–carbon adsorbent production was developed and optimized. The adsorbent was thoroughly studied by physical, chemical and biological methods, and was found to have high sorption capacity, long desorption time, high magnetization and low toxicity. The adsorbent is intended to be used for magnetically guided transport and forming a depot of anti-cancer drugs in the tumor zone.

Correlation of the coagulation rates and toxicity of biocompatible ferromagnetic microparticles

Interaction of four types of ferromagnetic microparticles with solid phase surfaces in biological media was studied and their acute toxicity compared. Stability of the colloidal system was found to depend on the surface properties, composition and structure of the particles and the solid phase. Increase in stability of the sol leads to decrease in toxicity of the particles.

Metal-organic magnetic materials based on cobalt phthalocyanine and possibilities of their application in medicine

Cobalt phthalocyanines (CoPc), doped with sodium, exhibit ferromagnetic ordering at room temperature. Magnetic dilution or variation in dopant concentration leads to the formation of new magnetic materials. A proposed scheme of oncological disease treatment includes magnetic concentration of CoPc particles in the tumor zone and ascorbic acid injection into the organism for stimulation of oxidation reactions, which destroy the tumor.

Single cell magnetophoresis and its diagnostic value

Abstract Magnetic separation of cells in suspension observed under a microscope is the subject of this paper. Parallel investigations of gravity sedimentation and magnetophoresis have been made. The ratio of magnetophoretic to sedimentation velocity of erythrocytes, intact cells and ferrocolloid-modified cells is shown to have diagnostic value for human diseases. Cell surface histocompatibility antigens were tested for magnetic immunospecific microparticles applications.

New manganite-based mediators for self-controlled magnetic heating

La?Ag and La?Na perovskite manganites could be considered as smart mediators for various biomedical applications requiring self-controlled isothermal heating including magnetic hyperthermia. Dissipation of the alternating magnetic field energy causes heating of their aqueous suspensions to terminate at 42?48??C without external temperature control. Termination temperatures of manganite suspensions are close to Tc and demonstrate, unlike other proposed mediator materials, a negligible dependence on the concentration of mediator particles in suspension.

New Method of Biological Fluid Detoxification Based on Magnetic Adsorbents

Existing methods of human organism detoxification such as hemoperfusion, hemodialysis and plasmapheresis are of low efficiency, damage cellular elements of blood, and require a significant volume of blood, complex and expensive hardware. We used finely dispersed magnetic adsorbents for hemosorption. A suspension of such particles, injected into an extracorporeal system, moves with the bloodstream and leads, due to the large specific surface of the magnetic adsorbents, to a fast and effective sorption process. The small size of the particles and very short and simple extracorporeal system does not damage cellular blood elements. Magnetic particles are then removed by a high gradient magnetic separator and the purified blood is returned to the organism. Effectiveness of the method was tested, and adsorbents for low, medium and high molecular weight compounds were selected. Animal experiments showed the high effectiveness of the technique for the removal of low-molecular weight toxins (barbiturates).

Magnetic and magnetic resonance studies of magnetically diluted phthalocyanine-based molecular magnets

Abstract Ferromagnetic ordering at room temperature is observed when cobalt phthalocyanines are doped with sodium. Magnetic dilution by diamagnetic metal-free phthalocyanines leads to a decrease in the magnetic ordering temperature and changes the magnetic characteristics. Micromagnetic behavior was obtained for the magnetically diluted samples after cooling in a magnetic field and in a zero magnetic field. The fine structure of the magnetic resonance absorption lines from Co 2+ ions has been detected in the magnetically diluted samples.

Magnetic-Fluid Induction Regional Hyperthermia of Sarcoma

Development of magnetic-fluid systems for the hyperthermia of tumors is necessary for increasing the efficiency of multicomponent therapy programs and decreasing the number of inoperable tumors not amenable to treatment because of technical limitations. Recent achievements in the induction hyperthermia therapy of oncologic patients, based on the thermal treatment of tumor tissues at 43 – 45°C, have stimulated further progress in this direction [1]. We have developed a method for the synthesis of magnetic nanoparticles of dextran ferrite (DF) No. 363, which were successfully tested in magnetic-fluid induction regional hyperthermia experiments in vitro [2]. The DF particles in our magnetic fluids, characterized by a low toxicity both in mice (LD50 = 5 g kg at pH 7.4) and in other experimental animals [3], can be considered as the ideal magnetic media for the given purpose [4]. The DF particles dissipate the alternating magnetic field energy via various loss channels and produce hyperthermia in the region of their location [1, 2, 4 – 7]. In the experiments in vitro, the survival of sarcoma MX11 cells as a function of the time of exposure at 44°C for heating provided by magnetic fluids based on DF No. 363 under RF induction treatment at a frequency of 0.88 MHz and a magnetic induction of 7.2 kA m was equivalent to the same exposure on a water bath [2]. A still unsolved technical problem encountered in RF induction hyperthermia in vivo is the difficulty of providing for uniform heating of only the tumor tissue, without any damage to surrounding normal tissues. The purpose of this study was to assess applicability of magnetic fluids (MFs) based on DF No. 363 for RF induction hyperthermia of sarcoma MX11 in vivo at a frequency of 0.88 MHz, a magnetic induction of 9.3 kA m, and a power of 0.15 kW.

Absorptive capacity of iron-based magnetic carriers for blood detoxification

Abstract The absorptive capacity of different magnetic carriers was investigated. Restored-iron, iron-carbon and iron-silica do not cause changes in erythrocytes’ osmotic resistance and possess high sorption efficiency for substances of different molecular mass. These magnetic carriers can be recommended for extracorporeal blood detoxification of low (barbiturates), middle (bilirubin) and high (heme proteins) molecular weight substances.