RU2109522C1 - Method of producing magnetic-operable composite for biomedical aims - Google Patents

Abstract

FIELD: inorganic chemistry, pharmacy. SUBSTANCE: highly dispersed powder Ferrum reductum is subjected for fractionation in inert gas flow at the rate 0.02-1.00 m/s at the range of magnetic field intensity 10-10³ A/m. Then iron particles are subjected for thermic treatment at 1000-1500 C in inert gas flow containing microparticles of carbon and/or silicon oxide, and/or aluminium oxide. Then surface of ferrosorbent particles is covered with biologically active compounds - food proteins or dextran, or drugs, or antibodies. EFFECT: improved method of producing. 4 cl, 1 tbl

Description

 The invention relates to physico-chemical medicine, in particular to a method for producing sorbents intended for biomedical research and clinical practice.

 Known methods for producing sorbents based on hydrocarbons, oxides of silicon, aluminum and their modifications, synthetic resins and their derivatives [1].

 However, the use of sorbents obtained by these methods in the clinic is associated with the simultaneous elimination of a large amount of blood from the body (200-400 ml), which limits the use of these sorbents for some categories of patients. Another disadvantage of using these sorbents, both in vivo and in vitro, is their low sorption capacity with respect to toxins.

The use of magnetically controlled composites as sorbents will reduce to 25-80 ml ^{3 the} volume of blood simultaneously withdrawn from the body through the use of a special magnetic separating device that allows for metered input and output of the sorbent during hemosorption.

и предназначенный для диагностики туберкулеза [2].Closest to the proposed production method and for biomedical purposes is a magnetically controlled sorbent based on iron - ferrosorbent obtained by the plasma-chemical method and representing iron particles with an average size of 50-100

and intended for the diagnosis of tuberculosis [2].

 The disadvantage of the ferrosorbent obtained by the plasma-chemical method, and the composite based on it, is the fundamental impossibility of their use in vivo and in vitro due to the small particle size, which leads to low values of the magnetic susceptibility of these particles, and therefore to remove them from biological media, the use of magnetic fields of 1-3 T is required. In accordance with health standards, the imposition of magnetic fields on biological objects, in particular blood, within 30-80 mT is permissible [3].

 Another disadvantage of the plasma-chemical method for producing ferrosorbent is the impossibility of chemical modification of the surface of the sorbent particles in the synthesis process, which limits the functionality of using this sorbent to remove toxins, especially medium and high molecular weight.

 The disadvantages of the method of producing ferroparticles should also include high energy intensity, labor intensity, the need to use complex, expensive equipment.

 The objective of the invention is to obtain a magnetically controlled composite of a certain chemical composition with a particle size of 0.5-2.5 μm and a magnetic susceptibility of 130-180 em / g, separated in magnetic fields of intensity up to 100 mT, expanding the functionality of the method and efficiency when removing low- , medium and high molecular weight toxins, microflora and retroviruses "in vivo" and "in vitro".

The problem is solved in that in a method for producing a magnetically controlled composite for biomedical purposes by heat treatment of iron powder Ferrum reductum, iron powder is preliminarily fractionated in the range of gas flow velocities of 0.02-1.00 m / s and in the range of magnetic field intensity of 10-10 ³ a / m to release the size of 0.5-2.5 micron iron particles and the heat treatment is carried out at 1000-1500 ^o C in an inert gas stream containing particles of modifying additives, followed by coating the particle surface biologists Eski active compounds, the treatment of iron particles is carried out in the presence of oxides of silicon and / or aluminum and / or / carbon, and the particles coated with food proteins ferrosorbenta or dextran and drugs, or antibodies.

 The method is as follows.

Highly dispersed iron powder (Ferrum reductum) is subjected to fractionation in an inert gas stream at a speed of 0.02-1.00 m / s and in the range of a magnetic field of 10-10 ³ A / m to isolate fractions of a certain particle size distribution (0.5-2 5 μm). Then the iron particles are subjected to heat treatment at 1000-1500 ^o C in an inert gas stream containing microparticles of coal and / or silicon oxide, and / or aluminum oxide, which are deposited on the surface of the iron particles. Obtained by the proposed method, iron particles and iron-carbon composites are coated with food proteins or dextran before contact with blood to reduce trauma to blood cells. At the same time, the sorption of low molecular weight toxins decreases slightly (by 10-12%), however, the sorption of high molecular weight toxins (hemoproteins) increases. The particles of the ferrosorbent or iron-carbon composite are coated with albumin (food) by sounding the mixture of sorbent and albumin on an ultrasonic disperser, followed by heating to 120 ^° C and cooling to room temperature. Coating the ferrosorbent particles with gelatin or dextran is also carried out by voicing a suspension of particles, followed by curing the coating with formalin and washing the resulting capsules with water. To destroy the pathogenic microflora and retroviruses and to remove antigens, the surface of the iron-carbon composite is modified with drugs and antibodies. Modification of drugs is carried out by the method of physical sorption in physiological saline at 40 ^o C. When using powder of ferrosorbent, the landing of drugs is carried out by the encapsulation method. The surface modification of the particles of a ferrosorbent or an iron-carbon composite for subsequent planting of antibodies is carried out by coating the particles with albumin or dextran, followed by activation with glutaraldehyde or sodium periodate.

 The proposed method obtained ferroparticles, iron-carbon composites and iron-silica gel composites with a particle size of 0.5-2.5 μm, magnetization 130-180 em / g. Magnetic separation of the obtained composites is feasible in fields of strength ≤ 100 mT.

The sorption efficiency of various types of composites with respect to low-, medium- and high-molecular substances was studied. Sodium phenobarbital was used as a model of low molecular weight substances, vitamin B _{12 was} used as medium molecular weight, hemoglobin was used as high molecular weight.

Sorption of substances on magnetically controlled composites was carried out in physiological saline at 37 ^o C with stirring for 15 s. Composites were separated in a field of a samarium-cobalt magnet with a strength of 100 mT.

 Example 1. As a sorbent used finely dispersed iron with an average particle size of 0.5-1.5 μm, the magnetic susceptibility of 130 em / g.

 Example 2. An iron-carbon composite with an average particle size of 0.5-2.0 μm and a magnetic susceptibility of 157 em / g were used as the sorbent.

 Example 3. As the sorbent used a composite of iron-silica gel with an average particle size of 1.0-2.5 μm, the magnetic susceptibility of 180 em / g.

 The values of sorption efficiency of the studied composites are presented in the table.

 Comparison of the results of the sorption efficiency of magnetically controlled composites with the data available in the literature [1, 4, 5] shows that the efficiency of magnetically controlled composites for sorption of low and high molecular weight substances is 30-50% higher than the known types of sorbents, and for sorption of medium molecular weight substances it corresponds to or slightly exceeds available data. The most promising in terms of sorption efficiency and hemocompatibility is an iron-silica gel composite that does not require a special coating.

Literature
1. Gorchakov V.D., Sergienko V.I., Vladimirov V.G., Selective hemosorbents, -M.: Medicine, 1989.

 2. Auth. St. N 1684616, publ. 10/15/91., B.I. N 38.

 3. Kutushov M.V., Author. diss. Candidate of Medical Science, M., 1990.

 4. Problems of technical support and clinical application of hemosorption and lymphosorption. Leningrad. 1984, p. 33-39.

 5. Ternovoi KS, Sorption detoxification in surgical practice, Kiev, 1985, p. 102-108.

Claims (4)

1. A method of producing a magnetically controlled powder for biomedical purposes, including heat treatment, characterized in that the Feppum reductum iron powder is preliminarily fractionated in the range of gas flow velocities of 0.02-1.00 m / s and in the range of magnetic field strength 10-10 ³ a / m with the release of iron particles of 0.5 - 2.5 microns, and the heat treatment is carried out at a temperature of 1000 - 1500 ^o C in an inert gas stream containing particles of modifying additives, followed by coating the particle surface biologi GOVERNMENTAL compounds.  2. The method according to claim 1, characterized in that as the modifying additives, silicon oxides and / or aluminum oxides and / or carbon are used.  3. The method according to PP.1 and 2, characterized in that as biologically active compounds using food proteins or dextran.  4. The method according to PP.1 and 2, characterized in that as biologically active compounds using drugs or antibodies.

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