RU2585781C2 - Hemo-plazmo-sorbent, methods for production (versions) and use thereof - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention relates to sorbents based on granulated activated carbon, modified polypyrrole used in medicine. Disclosed are two electrochemical versions of sorbent producing method. According to first version, method is carried out in aqueous electrolyte with dodecyl sulphate ions. According to second version, method is carried out with non-aqueous solvent with chloride ions. Obtained sorbent contains polypyrrole doped with chloride ion, which covers approximately 5.0 % of carbon granules surface. For electrochemically controlled hemo- or plasma sorption outer potentiostatic polarization of sorbent during sorption is carried out in range from -0.2 V to +0.2 V relative to silver chloride reference electrode. Speed of pumping blood or blood plasma corresponds to natural human blood flow rate equal to approximately 150 ml/min.

EFFECT: invention provides possibility of removal from blood or blood plasma of toxic substances with different molecular weight and allows controlling process of removal of these substances.

4 cl, 1 dwg, 3 tbl

Description

Technical field

The invention relates to medicine and can be used for the manufacture and use of hemoplasma sorbents based on granular activated carbons by modifying them with polypyrrole.

State of the art

In the closest analogue according to the patent of the Russian Federation No. 2509564 "Plasma sorbent selective for free hemoglobin and the method for its production" (IPC A61K 33/44, A61M 1/38, B01J 20/02, G01N 33/49, publ. 20.03.2014) describes plasmosorbent, a method for its manufacture and use based on granular activated carbons by modifying them with polypyrrole and divalent copper ions to remove free hemoglobin from human biological fluids (plasma).

A prototype method of manufacturing a plasma sorbent is that the initial granular activated carbon is dedusted, placed in an electrolyzer containing an electrolyte from an aqueous solution of sodium chloride at a concentration of 3.42 mol / l, pyrrole at a concentration of from 0.14 to 0.89 mol / l and copper sulfate (dopant) with a concentration of 0.10 mol / L, and polarized anodically using the synthesis of polypyrrole doped with dopant ion. The electrolysis of pyrrole is carried out in a potentiostatic mode with a constant potential of 0.8 V relative to a saturated silver chloride reference electrode on the surface of a pre-dusted initial granular activated carbon. After the deposition of polypyrrole together with copper ions in an amount corresponding to a coating of 1.0 to 3.0% of the surface of the coal, the modified granular activated carbon is washed with saline sodium chloride at a concentration of 0.15 mol / l, the result is a plasma sorbent.

A method of using a plasma sorbent is that the obtained plasma sorbent is placed in a cylindrical column through which blood plasma containing free hemoglobin is pumped with a peristaltic pump at a rate of 100 ml / min. The invention provides the removal of free hemoglobin by sorption of human blood plasma by creating a selective plasma sorbent.

The limitations of the prototype can recognize the following points:

- a narrow range of possibilities for using selective plasma sorbent only for sorption of blood plasma because of its aggressiveness to blood itself due to the presence of copper ions in the sorbent, which is necessary to remove free hemoglobin from blood plasma, but not to adsorb exo- and endotoxicants from the blood and blood plasma;

- a narrow range of manufacturing capabilities of selective plasma sorbent - described only one version of the manufacturing method;

- in addition, the original activated carbon of the SKT-6A grade indicated in the examples of the prototype is not currently being produced.

Disclosure of invention

The technical result of the invention is to expand the functionality of the options for obtaining and using the sorbent for the adsorption removal of exo- and endotoxicants from blood, blood plasma.

The proposed sorbent is intended for use in medicine for extracorporeal detoxification of the body by adsorption removal of exo- and endotoxicants from blood, blood plasma. In addition, the sorbent is made of cheap granular activated carbon produced or offered for production in the domestic industry in industrial volumes.

To achieve a technical result, 2 independent manufacturing options of the proposed sorbent are proposed with the replacement of copper ions from the prototype with other ions:

option 1: with an aqueous solvent in an electrolyte with dodecyl sulfate ions (DS ^- );

option 2: with non-aqueous solvent in an electrolyte with chloride ions.

According to option 1, the method of manufacturing a hemoplasmosorbent consists in dedusting the initial granular activated carbon, placing it in an electrolytic cell containing an electrolyte from an aqueous solution of sodium chloride NaCl, pyrrole and dopant, and polarizing anodically using the synthesis of polypyrrole doped with dopant ion. The electrolysis of pyrrole is carried out in a potentiostatic mode with a constant potential of 0.8 V relative to a saturated silver chloride reference electrode on the surface of a pre-dusted initial granular activated carbon. After electropolymerization and precipitation of polypyrrole, the modified granular activated carbon is washed with a saline solution of sodium chloride with a concentration of 0.15 mol / L, the result is a sorbent. At the same time, in the electrolyte, the concentration of an aqueous solution of sodium chloride 0.15 mol / L and pyrrole 0.10 mol / L additionally contains sodium dodecyl sulfate (sodium dodecyl sulfate (SDS)) at a concentration of 25 mmol / L. And polypyrrole doped with dodecyl sulfate ion (DS ^- ), covers about 5.0% of the surface of the granules of the obtained sorbent.

According to option 2, the method of manufacturing the hemoplasmosorbent consists in dedusting the initial granular activated carbon, placing it in an electrolytic cell containing an electrolyte from a solution of a substance with dopant chloride and pyrrole chloride, and polarizing it anodically using polypyrrole synthesis doped with dopant ion. The electrolysis of pyrrole is carried out in a potentiostatic mode with a constant potential relative to a saturated silver-silver reference electrode on the surface of a pre-dusted initial granular activated carbon. After electropolymerization and deposition of polypyrrole, the modified granular activated carbon is washed, including with a saline solution of sodium chloride with a concentration of 0.15 mol / L, and a sorbent is obtained. In this case, in an electrolyte from a non-aqueous solution of acetonitrile for the synthesis of polypyrrole doped with chloride ion, the composition is used: 0.10 mol / L tetraethylammonium chloride Et ₄ NCl and 0.10 mol / L pyrrole. The electrolysis of pyrrole is carried out at a potential of 1.3 V relative to a saturated silver chloride reference electrode. After carrying out the electropolymerization of pyrrole and precipitation of polypyrrole, the modified samples are washed with acetonitrile, then dried and finally washed with physiological saline. Polypyrrole doped with chloride ion covers about 5.0% of the surface of the granules of the obtained sorbent.

The following is a method of using a hemoplasma sorbent for adsorptive removal of exo- and endotoxicants from blood, blood plasma, namely, that the sorbent consisting of granular activated carbon coated with polypyrrole according to any of two independent manufacturing options is placed in a cylindrical column, through which blood or plasma is pumped with a peristaltic pump. In this case, for electrochemically controlled hemo- or plasma sorption, the column is equipped with current leads and an auxiliary electrode for external polarization. External potentiostatic polarization of the sorbent during sorption is carried out in the range from -0.2 V to +0.2 V relative to the silver chloride reference electrode, while the rate of pumping of blood and blood plasma corresponds to the rate of human natural blood flow, i.e., about 150 ml / min.

The hemoplasmosorbent itself for adsorptive removal of exo- and endotoxicants from blood and blood plasma consists of modified granular activated carbon, while part of the surface of the coal, namely about 5.0%, is coated with doped polypyrrole in accordance with any of two independent options manufacturing sorbent. Moreover, the initial granular activated carbon itself is taken from industrial carbons produced in the domestic industry in industrial volumes, mainly of the AR-1 grade.

The proposed hemoplasm sorbent has increased adsorption activity with respect to toxic substances compared to existing sorbents. The invention provides for the removal from the blood, as well as from blood plasma, of toxic substances of various molecular weights. The use of electrically conductive materials in the composition of the sorbent allows you to regulate the process of removal of toxic substances. Sorbent practically does not damage the formed elements of the blood (red blood cells, white blood cells).

In FIG. 1 presents a schematic flow diagram of a pilot experimental setup used both for the production and for preclinical trials of the application of the proposed hemoplasmosorbent.

The implementation of the invention

The positions in the block diagram of the experimental setup indicate: 1 - a column for producing coal (electrolyzer) (it is conventionally drawn how densely laid granular coal is located inside the column); 2 - peristaltic pump; 3 - potentiostat; 4 - computer; 5 - capacity with electrolyte; 6 - trunk for supply and removal of electrolyte.

The circuit is three-electrode: the main electrode is the mass of the densely packed granules of the source carbon themselves (to ensure uniformity of electro-polarization of the total volume of activated carbon in the manufacture of the sorbent, its granules must be compressed together, ensuring their tight contact), the auxiliary electrode is a pin from this mass and the column ( as the material of the auxiliary electrode, either thermally expanded graphite (TEG) or any other carbon material with a developed surface and inert with respect to wearing to electrolyte); and the third electrode, to control the process of electropolymerization and deposition, a silver chloride reference electrode. In this case, the voltage between the working electrode and the reference electrode is measured, which is called the potential of the working electrode. The presence of a potentiostat 3 associated with the control and recording computer 4, and a reference electrode allows the process of electropolymerization in a potentiostatic mode. As a reference electrode, any commercial reference electrode may be used, for example, a saturated silver chloride chloride electrode (HSE). Note: in the future, on a scale of industrial (rather than experimental) production of the proposed sorbent, instead of such a scheme with a column with a reference electrode, a large galvanic bath without a reference electrode will probably be used.

The electrolyte solution from the tank 5 using the pump 2 through the line 6 is fed into the cell 1. The volume of the cell 1 is filled with tightly packed and compressed granules of activated carbon. Current leads are connected to the granules of coal, through which a predetermined potential is supplied to the coal from a power source (potentiostat 3). The solution from the electrolyzer 1 through another line 6 enters the tank 5 with electrolyte.

The electrochemical polymerization of pyrrole to polypyrrole is carried out in a solution containing pyrrole monomer, an aqueous or non-aqueous solvent, and an electrolyte (source of dopant anion). The deposition of polypyrrole occurs on a positively charged electrode (anode) when an electric current passes through a solution. The product of the electrochemical polymerization reaction is an electrically conductive film on the surface of the electrode with high conductivity, high adhesive activity to the surface, the current efficiency is close to 100%, which makes it possible to obtain a polymer of the desired mass and thickness.

An example of the preparation and use of hemoplasm sorbent

The electrolysis of pyrrole begins:

- from aqueous solvents with a potential (relative to a saturated silver chloride reference electrode) of more than 0.35 V. In version 1 of the manufacturing method, a potential of 0.8 V was used, which is optimal in combination with the concentration parameters of an aqueous solution of sodium chloride 0.15 mol / L in the electrolyte and pyrrole 0.10 mol / L with an additional content of sodium dodecyl sulfate concentration of 25 mmol / L, for about 5% coverage of the granule area of activated carbon with polypyrrole doped with dodecyl sulfate ion;

- from non-aqueous solvents - with a potential greater than 0.65 V. In option 2 of the manufacturing method, a potential of 1.3 V was used, which is optimal in combination with the concentration parameters in an electrolyte from a non-aqueous solution of acetonitrile of the composition: 0.10 mol / L tetraethylammonium chloride Et ₄ NCl and 0.10 mol / L pyrrole for about 5% coverage of the area of the activated carbon granules with polypyrrole doped with chloride ion.

The static mode of electrolysis of pyrrole is preferable to the dynamic one, since the static mode is closer to the equilibrium mode and is easier to control using instruments and a personal computer.

The potentiostatic mode of polymerization involves a change in the polarization current at a constant potential. The integral of the current-time curve is the amount of electricity spent on the electrolysis of pyrrole, with which it is possible to determine the mass of the polymer or its thickness on the surface.

The time of the polymerization process depends on the mass of the modified activated carbon (in tests, the sorbent mass range was from 100 to 300 g) and is several tens of minutes (on average about 30 minutes). The electrolysis of pyrrole is carried out at a current density of 5 to 10 mA / m ² under normal conditions at room temperature. The electrolysis of pyrrole is completed with the passage of the required amount of electricity (from several tens to several hundred units of C). A sufficient amount of polypyrrole polymer is deposited on the surface of the coal to cover an integral surface area of coal of about 5%.

After electropolymerization and precipitation of polypyrrole in embodiment 1 of the manufacturing method, the modified granular activated carbon is washed with saline sodium chloride.

After carrying out the electropolymerization of pyrrole and precipitation of polypyrrole in embodiment 2 of the manufacturing method, the modified samples are washed with acetonitrile, then dried and finally washed with physiological saline.

Next, the finished sorbent is placed in another cylindrical column, adapted for electrochemically controlled hemosorption. This cylindrical column is also equipped with a current lead, an auxiliary electrode and a chlorine-containing reference electrode for additional external polarization in the range from -0.2 V to +0.2 V relative to the silver-silver reference electrode to maintain the sorbent in a constant highly efficient state during the sorption process. At the same time, the optimal speed of pumping blood and blood plasma corresponds to the rate of human natural blood flow, that is, about 150 ml / min.

The hemoplasma sorbent itself for adsorptive removal of exo- and endotoxicants from blood and blood plasma consists of modified granular activated carbon, and about 5.0% of the surface of the coal is coated with doped polypyrrole in accordance with any of two independent sorbent manufacturing options. Moreover, the initial granular activated carbon itself is taken from industrial carbons produced in domestic industry in industrial volumes. In experiments in the experimental setup (Fig. 1), Russian industrial coal of the AR-1 grade was used as the initial granular activated carbon, which was fully suitable for the technical characteristics of the granule size, specific surface, granule strength during abrasion, dust, ash and adsorption capacity methylene blue. In the future, you can also use the State contract developed in the framework of R&D by order of the Ministry of Industry and Trade of the Russian Federation at MSTU named after N.E. Bauman together with the Research Institute of Ambulance them. N.V. Sklifosovsky is even cheaper, but effective granular activated carbon and the sorbent obtained from it according to TU 9398-091-05754293-2014, which is currently undergoing preclinical certification tests. Its characteristics are shown in table 1 in comparison with the known granular coals of the VNIITU-1 and FAS brands.

To test the adsorption activity of the sorbent with respect to exo- and endotoxicants from blood and blood plasma, a sorbent of 100 g was placed in a cylindrical column equipped with a current lead and an auxiliary electrode for external polarization of the sorbent, through which a peristaltic pump was pumped into the blood. An additional external polarization in the range from -0.2 V to +0.2 V relative to the silver chloride reference electrode was used to maintain the sorbent in a constant highly efficient state during the sorption process, while the optimal rate of pumping blood and blood plasma corresponded to the rate of natural human blood flow of 150 ml / min

Assessment of the biocompatibility of the sorbent was carried out using a culture of diploid cells of a human embryo (LCD) - fibroblasts of the M-22 line; human blood cells - red blood cells (from whole blood of donors and donor erythromass), white blood cells (from whole blood of donors and donor’s leukotrombolayer), platelets (from whole donor blood, donor’s thrombocyte and donor thrombocyte concentration). The assessment was carried out before and after the sorption procedure, according to GOST R ISO 10993-5-2009. The evaluation results are presented in table 2.

All results are confirmed by acts of biological and toxicological preclinical trials in certified Russian medical laboratories.

In the program of preclinical trials, the concentration of bilirubin acts as an indicator of endotoxicity of blood and blood plasma, and the concentrations of copper and lead are indicators of exotoxification. Table 3 presents these indicators together with biochemical indicators with ranges of acceptable values, as well as the results of experimental applications of sorbents obtained by independent variants 1 and 2 of the manufacturing method.

The above data indicate a rather high efficiency of the application of the State Contract developed as part of R&D commissioned by the Ministry of Industry and Trade of the Russian Federation at MSTU named after N.E. Bauman together with the Research Institute of Ambulance them. N.V. Sklifosovsky hemoplasmosorbent for extracorporeal detoxification of the body by adsorption removal of exo- and endotoxicants from blood, blood plasma.

Claims (4)

1. A method of manufacturing a hemoplasmosorbent, which consists in the fact that the initial granular activated carbon is dedusted, placed in an electrolyzer containing an electrolyte from an aqueous solution of sodium chloride NaCl, pyrrole and dopant, and polarized anodically using the synthesis of polypyrrole doped with dopant ion, the pyrrole is electropolymerized in a potentiostatic mode at a constant potential of 0.8 V relative to a saturated silver-silver reference electrode on the surface of a previously dust-free initial granule of activated carbon, after precipitation of polypyrrole, the modified granular activated carbon is washed, including with a saline solution of sodium chloride with a concentration of 0.15 mol / l, as a result, a sorbent is obtained, characterized in that the concentration of an aqueous solution of sodium chloride in the electrolyte is 0.15 mol / l and pyrrole 0.10 mol / L the electrolyte additionally contains sodium dodecyl sulfate (SDS) with a concentration of 25 mmol / l, while polypyrrole doped with dodecyl sulfate ion (DS) covers about 5.0% of the surface of the granules obtained sorbent. 2. A method of manufacturing a hemoplasmosorbent, which consists in the fact that the initial granular activated carbon is dedusted, placed in an electrolyzer containing an electrolyte from a solution of a substance with dopant chloride and pyrrole, and polarized anodically using the synthesis of polypyrrole doped with dopant ion, pyrrole electropolymerization produced in a potentiostatic mode with a constant potential relative to a saturated silver-silver chloride reference electrode on the surface of a pre-dustless initial granular of activated carbon, after the deposition of polypyrrole, the modified granular activated carbon is washed, including with a saline solution of sodium chloride with a concentration of 0.15 mol / l, as a result, a sorbent is obtained, characterized in that in an electrolyte from a non-aqueous solution of acetonitrile for the synthesis of polypyrrole doped with chloride ion, using the composition: 0.10 mol / l of tetraethylammonium chloride Et ₄ NCl and 0.10 mol / l of pyrrole, the electrolysis of pyrrole is carried out at a potential of 1.3 V relative to a saturated silver chloride comparison electrode, after the electrolysis of pyrrole, the modified samples are washed with acetonitrile, then dried and finally washed with physiological saline, while polypyrrole covers about 5.0% of the surface of the granules of the obtained sorbent. 3. A method of using a hemoplasma sorbent for adsorptive removal of exo- and endotoxicants from blood, blood plasma, which consists in the fact that the sorbent, consisting of granular activated carbon coated with polypyrrole, obtained according to claim 1 or 2, is placed in a cylindrical column through which a blood or blood plasma is pumped through a peristaltic pump, characterized in that for the electrochemically controlled hemo- or plasma sorption, the column is equipped with current leads and an auxiliary electrode for external polarization, w potentiostatic polarization sorbent during sorption is carried out in the range of 0.2 The relative V to +0.2 V relative to silver-silver chloride reference electrode, wherein pumping rate of the blood, blood plasma corresponds to the natural human blood velocity, i.e. about 150 ml / min. 4. Hemoplasmosorbent for adsorptive removal of exo- and endotoxicants from blood, blood plasma, consisting of modified granular activated carbon, in which about 5.0% of the surface of the coal is coated with polypyrrole, obtained in accordance with the methods described in paragraph 1 or 2, while the initial granular activated carbon is industrial coal, mainly of the brand AP-1.

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