A heparin-capturing uremic toxin adsorbent and preparation method thereof

Abstract

The present invention relates to the field of biomedicine technology, and proposes a heparin-capturing uremic toxin adsorbent and a preparation method thereof. The raw materials of the adsorbent include styrene, acrylic acid, and divinylbenzene. Through the above technical solution, using polystyrene as the basic skeleton, by introducing polar monomers into the main structure, and activating the introduction of active groups such as hydroxyl and chloromethyl groups on the skeleton surface, a heparin-capturing adsorbent is prepared that can be rapidly cross-linked with heparin surface active groups through physical and chemical reactions to form an anti-coagulant surface. This solves the problem in the prior art that uremic toxin adsorbents can cause coagulation complications when used clinically.

Description

Technical Field

[0001] The present invention relates to the technical field of biomedicine, and in particular to a heparin-capturing uremic toxin adsorbent and a preparation method thereof. Background Art

[0002] Renal failure is a pathological condition characterized by partial or complete loss of renal function in the late stages of various kidney diseases. With the loss of renal excretion, hundreds of toxic metabolic products accumulate in the blood and tissues. Uremic toxins generally include: ① Small molecule, water-soluble toxins, such as urea, creatinine, and uric acid, which can be removed through hemodialysis; ② Medium molecule toxins, such as parathyroid hormone, prostacyclin, β2-microglobulin, and leptin, which can be removed through high-flux dialysis or hemoperfusion; and ③ Large molecule toxins or protein-bound toxins. These toxins are large in molecular weight (e.g., tumor necrosis factor: approximately 51 kd) or are bound to albumin (e.g., indoxyl sulfate, p-cresol sulfate, etc.). These toxins cannot be removed through dialysis, but hemoperfusion is an effective means of removal.

[0003] Hemoperfusion is a blood purification method that involves introducing a patient's blood into a perfusion device filled with a solid adsorbent. Through adsorption, it removes exogenous or endogenous toxins from the blood. It has been widely used clinically to remove uremic toxins that are difficult to remove through dialysis. Currently, the main patents for adsorbents used to remove uremic toxins include: an adsorbent with a polystyrene carrier (CN108371945A), which can effectively remove large molecular toxins in uremia; a polypeptide ligand adsorbent with a polystyrene carrier (CN111701580A), which can specifically remove β2-microglobulin from uremic patients; and a molecularly imprinted adsorbent with a polystyrene backbone (CN112791712B), which can efficiently remove protein-bound toxins. The main adsorbent products used clinically for the removal of uremic toxins include the Zhuhai Jianfan HA series and the Foshan Boxin MG series.

[0004] Currently, most adsorbent products for hemoperfusion in uremia are coated with materials such as collodion, polyvinyl alcohol, and polyvinyl pyrrolidone to improve their blood compatibility. Although these products are pre-flushed with large amounts of heparin before clinical use and also use heparin for anticoagulation during treatment, coagulation remains one of the most common complications, resulting in significant adverse psychological impacts for patients. Summary of the Invention

[0005] The present invention provides a heparin-capturing uremic toxin adsorbent and a preparation method thereof, which solves the problem in the related art that uremic toxin adsorbents may cause coagulation complications during clinical use.

[0006] The technical solutions of the present invention are as follows:

[0007] A heparin-capturing uremic toxin adsorbent, wherein the raw materials of the adsorbent include styrene, acrylic acid and divinylbenzene.

[0008] As a further technical solution, the adsorbent is obtained by polymerizing styrene, acrylic acid and divinylbenzene, and the mass ratio of styrene, acrylic acid and divinylbenzene is 5-20:5-15:70-90.

[0009] As a further technical solution, the adsorbent has a particle size of 0.3-1.2 mm, a water content of 55-77%, and a specific surface area of ​​500-900 m 2 / g.

[0010] The present invention also includes a method for preparing a heparin-captured uremic toxin adsorbent, comprising the following steps:

[0011] S1, mixing styrene, acrylic acid, divinylbenzene, a porogen and an initiator to obtain an oil phase;

[0012] S2, mixing polyvinyl alcohol, sodium chloride and water to obtain an aqueous phase;

[0013] S3, mixing the oil phase and the water phase for reaction, and removing the porogen to obtain resin I;

[0014] S4, after resin I is subjected to chlorination reaction, resin II is obtained;

[0015] S5. Hydrolyze resin II to obtain an adsorbent.

[0016] As a further technical solution, the mass ratio of styrene, acrylic acid, divinylbenzene, porogen and initiator in S1 is 5-20:5-15:70-90:100-150:0.5-1.5.

[0017] As a further technical solution, the purity of divinylbenzene in S1 is 80%.

[0018] As a further technical solution, the mass concentration of polyvinyl alcohol in the S2 aqueous phase is 0.5%-2%, and the mass concentration of sodium chloride is 3%-8%.

[0019] As a further technical solution, the mass ratio of the water phase to the oil phase in S3 is 2-4:1.

[0020] As a further technical solution, the reaction temperature in S3 is 78-90° C. and the reaction time is 4-12 h.

[0021] As a further technical solution, the water content of the resin I in S3 is ≤5%.

[0022] As a further technical solution, the chlorination reaction in S4 is as follows: adding resin I to chloromethyl ether, swelling at 30-45°C for 2-24 hours, adding ferric chloride and reacting at 42-45°C for 2-24 hours; the mass ratio of resin I to chloromethyl ether is 1:3-7; and the amount of ferric chloride added is 1-20% of the mass of resin I.

[0023] As a further technical solution, the hydrolysis in S5 is to add resin II into a sodium hydroxide solution for hydrolysis.

[0024] As a further technical solution, the mass ratio of the sodium hydroxide solution to the resin II in S5 is 2-6:1.

[0025] As a further technical solution, the concentration of the sodium hydroxide solution in S5 is 1-3 mol / L.

[0026] As a further technical solution, the hydrolysis in S5 is carried out at 70-90° C. for 12-24 hours.

[0027] As a further technical solution, the porogen in S1 is a mixture of a first porogen and a second porogen, the first porogen is one of an alkane or an aromatic hydrocarbon, and the second porogen is one of an alcohol or an ester; the first porogen accounts for 50%-70% of the total mass of the porogen.

[0028] As a further technical solution, the first porogen includes one of toluene, liquid wax, n-heptane or 200# gasoline

[0029] As a further technical solution, the second porogen includes one of n-octanol, butyl acetate, n-butanol, isobutanol, cyclohexanol or isopentanol.

[0030] As a further technical solution, the hydrolysis in S5 is carried out at 70-90° C. for 12-24 hours.

[0031] As a further technical solution, the adsorbent has a carboxyl content of 1.0-1.5 mmol / g, a hydroxyl content of 1.0-2.0 mmol / g, and a chloromethyl content of 1.0-2.5 mmol / g.

[0032] The working principle and beneficial effects of the present invention are:

[0033] 1. The present invention provides a novel hemoperfusion adsorbent for uremic toxins that can rapidly capture heparin. The adsorbent is a porous polystyrene-acrylic acid-divinylbenzene framework resin with multiple active sites. The resin surface active groups can rapidly bind to heparin through physical and chemical means, thereby forming an anticoagulant surface layer. The adsorbent not only has excellent anticoagulant properties but also has a significant scavenging effect on protein-bound toxins. Furthermore, when the mass ratio of styrene, acrylic acid, and divinylbenzene is 5-20:5-15:70-90, the adsorbent's anticoagulant properties and scavenging effect on protein-bound toxins are further enhanced.

[0034] 2. The blood purification adsorbent provided by the present invention uses ternary copolymerization to introduce polar groups (carboxyl groups), chloromethyl groups introduced by chlorination, and hydroxyl groups introduced by hydrolysis. These active groups can cross-link with the amino groups, sulfonic acid groups, and hydroxyl groups on heparin through chemical and physical methods, quickly forming a layer of anticoagulant surface, greatly improving the anticoagulant performance of the adsorbent. At the same time, the high specific surface area and the introduction of active ligands also give the adsorbent a good adsorption effect on medium and large molecular toxins in uremia. In the chlorination process, compared with zinc chloride, the use of ferric chloride in the present invention can further improve the adsorption performance of the adsorbent and reduce the decline of red blood cells, white blood cells, and platelets in the blood.

[0035] 3. The blood purification adsorbent provided by this invention, through the use of a mixed porogen during suspension polymerization, introduces a 10-50 nm mesoporous structure and active groups, enabling rapid heparinization and multi-target adsorption of uremic toxins. The adsorbent preparation process is simple, employing mild conditions, and eliminates the need for coating processes, saving significant amounts of organic solvents and contributing to environmental benefits and cost reduction. DETAILED DESCRIPTION

[0036] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0037] The purity of divinylbenzene in the following examples and comparative examples is 80%.

[0038] Example 1

[0039] (1) Polymerization reaction: 15 g of styrene, 15 g of acrylic acid, 70 g of divinylbenzene, 50 g of toluene, 50 g of n-octanol, and 1.5 g of BPO were uniformly mixed to prepare an oil phase; 10 g of polyvinyl alcohol, 50 g of sodium chloride, and 940 g of water were mixed to prepare an aqueous phase; 50 g of the oil phase was added to 200 g of a 50° C. aqueous phase, mixed and allowed to stand for 10 min, stirred, and heated to 90° C. at a rate of 1° C. / 2 min. After keeping the temperature for 12 h, the reaction was stopped and filtered. The solid was washed with 50° C. water until the effluent was clear, the toluene and n-octanol were extracted with ethanol, and then transferred to the aqueous phase. The solid was sieved in a wet state to obtain a solid with a particle size of 0.3-1.2 mm. The solid was dried to a moisture content of 3% to obtain resin I;

[0040] (2) Chlorination reaction: Weigh 50 g of the resin I obtained in step (1) above and 250 g of chloromethyl ether and add them to a reactor. Swell at 30° C. for 12 h. After swelling, add 5 g of ferric chloride and continue stirring. Raise the temperature to 42° C. and keep warm for 12 h. Discharge the mixture to obtain resin II.

[0041] (3) Hydrolysis Reaction: Weigh 50 g of Resin II obtained in step (2) above and slowly add 200 g of a 2 mol / L sodium hydroxide aqueous solution. After sufficient dissolution under slow stirring, heat to 70°C at a rate of 5°C / 5 min and react for 24 h. After the reaction is complete, stop heating, cool to 40°C, stop stirring, and remove from the pellets to obtain the finished product for later use.

[0042] The product obtained in Example 1 has the appearance of white opaque beads, a particle size of 0.4-0.9 mm, a water content of 65%, a carboxyl content of 1.0 mmol / g, a hydroxyl content of 2.0 mmol / g, a chloromethyl content of 1.5 mmol / g, and a specific surface area of ​​800 m 2 / g.

[0043] Example 2

[0044] (1) Polymerization reaction: 5 g of styrene, 5 g of acrylic acid, 90 g of divinylbenzene, 100 g of toluene, 50 g of n-octanol, and 0.5 g of BPO were uniformly mixed to prepare an oil phase; 5 g of polyvinyl alcohol, 80 g of sodium chloride, and 915 g of water were mixed to prepare an aqueous phase; 50 g of the oil phase was added to 150 g of a 50° C. aqueous phase, mixed and allowed to stand for 10 min, stirred, and heated to 80° C. at a rate of 1° C. / 2 min. After keeping warm for 10 h, the reaction was stopped and filtered. The solid was washed with 50° C. water until the effluent was clear, the toluene and n-octanol were extracted with ethanol, and then transferred to the aqueous phase. The solid was sieved in a wet state to obtain a solid with a particle size of 0.3-1.2 mm. The solid was dried to a moisture content of 3% to obtain resin I;

[0045] (2) Chlorination reaction: Weigh 50 g of the resin I obtained in step (1) above and 250 g of chloromethyl ether and add them to a reactor. Swell at 35° C. for 8 h. After swelling, add 10 g of ferric chloride and continue stirring. Raise the temperature to 45° C. and keep warm for 8 h. Discharge the mixture to obtain resin II.

[0046] (3) Hydrolysis Reaction: Weigh 50 g of Resin II obtained in step (2) above, slowly add 100 g of 3 mol / L sodium hydroxide aqueous solution, slowly stir until fully dissolved, then heat to 80°C at a rate of 5°C / 5 min and react for 12 h. After the reaction is complete, stop heating, cool to 40°C, stop stirring, and remove from the pellets to obtain the finished product for later use.

[0047] The product obtained in Example 2 has the appearance of light yellow opaque beads, a particle size of 0.4-1.0 mm, a water content of 60%, a carboxyl content of 1.0 mmol / g, a hydroxyl content of 1.5 mmol / g, a chloromethyl content of 2.0 mmol / g, and a specific surface area of ​​900 m 2 / g.

[0048] Example 3

[0049] (1) Polymerization reaction: 5 g of styrene, 15 g of acrylic acid, 80 g of divinylbenzene, 100 g of toluene, 50 g of butyl acetate, and 0.5 g of BPO were uniformly mixed to prepare an oil phase; 10 g of polyvinyl alcohol, 30 g of sodium chloride, and 960 g of water were mixed to prepare an aqueous phase; 50 g of the oil phase was added to 200 g of a 50° C. aqueous phase, mixed and allowed to stand for 10 min, stirred, and heated to 80° C. at a rate of 1° C. / 2 min. After keeping the temperature for 8 h, the reaction was stopped and filtered. The solid was washed with 50° C. water until the effluent was clear, toluene and butyl acetate were extracted with ethanol, and then transferred to the aqueous phase. A solid with a particle size of 0.3-1.2 mm was obtained by wet sieving, and the solid was dried to a moisture content of 1% to obtain resin I;

[0050] (2) Chlorination reaction: Weigh 50 g of the resin I obtained in step (1) above and 350 g of chloromethyl ether and add them to a reactor. Swell at 45° C. for 24 h. After swelling, add 2.5 g of ferric chloride and continue stirring. Raise the temperature to 45° C. and keep warm for 24 h. Discharge the mixture to obtain resin II.

[0051] (3) Hydrolysis Reaction: Weigh 50 g of the resin II obtained in step (2) above, slowly add 300 g of a 1 mol / L sodium hydroxide aqueous solution, slowly stir until fully dissolved, then heat to 90°C at a rate of 5°C / 5 min and react for 24 h. After the reaction is complete, stop heating, cool to 40°C, stop stirring, and remove the pellets to prepare an adsorbent.

[0052] The product obtained in Example 3 has the appearance of white opaque beads, a particle size of 0.4-1.0 mm, a water content of 56%, a carboxyl content of 2.0 mmol / g, a hydroxyl content of 1.5 mmol / g, a chloromethyl content of 2.5 mmol / g, and a specific surface area of ​​700 m 2 / g.

[0053] Example 4

[0054] (1) Polymerization reaction: 20 g of styrene, 5 g of acrylic acid, 70 g of divinylbenzene, 70 g of toluene, 30 g of n-octanol, and 0.8 g of BPO were uniformly mixed to prepare an oil phase; 20 g of polyvinyl alcohol, 30 g of sodium chloride, and 950 g of water were mixed to prepare an aqueous phase; 50 g of the oil phase was added to 200 g of a 50° C. aqueous phase, mixed and allowed to stand for 10 min, stirred, and heated to 78° C. at a rate of 1° C. / 2 min. After keeping warm for 12 h, the reaction was stopped and filtered. The solid was washed with 50° C. water until the effluent was clear, the toluene and n-octanol were extracted with ethanol, and then transferred to the aqueous phase. A solid with a particle size of 0.3-1.2 mm was obtained by wet sieving, and the solid was dried to a moisture content of 3% to obtain resin I;

[0055] (2) Chlorination reaction: Weigh 50 g of the resin I obtained in step (1) above and 150 g of chloromethyl ether and add them to a reactor. Swell at 30° C. for 12 h. After swelling, add 0.5 g of ferric chloride. Continue stirring and heat to 45° C., keep warm for 12 h, and discharge to obtain resin II.

[0056] (3) Hydrolysis Reaction: Weigh 50 g of Resin II obtained in step (2) above and slowly add 200 g of a 2 mol / L sodium hydroxide aqueous solution. After sufficient dissolution under slow stirring, heat to 70°C at a rate of 5°C / 5 min and react for 24 h. After the reaction is complete, stop heating, cool to 40°C, stop stirring, and remove from the pellets to obtain the finished product for later use.

[0057] The product obtained in Example 4 has the appearance of white opaque beads, a particle size of 0.8-1.2 mm, a water content of 56%, a carboxyl content of 0.8 mmol / g, a hydroxyl content of 2.0 mmol / g, a chloromethyl content of 1.0 mmol / g, and a specific surface area of ​​600 m 2 / g.

[0058] Example 5

[0059] 15g of styrene, 15g of acrylic acid, 70g of divinylbenzene, 50g of toluene, 50g of n-octanol, and 1.5g of BPO were uniformly mixed to prepare an oil phase; 10g of polyvinyl alcohol, 50g of sodium chloride, and 940g of water were mixed to prepare an aqueous phase; 50g of the oil phase was added to 200g of the 50°C aqueous phase, mixed, and allowed to stand for 10 minutes. Stirring was started, and the temperature was raised to 90°C at a rate of 1°C / 2min. After keeping the temperature for 12 hours, the reaction was stopped and filtered. The solid was washed with 50°C water until the effluent was clear, the toluene and n-octanol were extracted with ethanol, and then transferred to the aqueous phase. After wet sieving, a solid with a particle size of 0.3-1.2mm was obtained, which was the adsorbent.

[0060] The product obtained in Example 5 has the appearance of white opaque beads with a particle size of 0.5-0.8 mm, a carboxyl content of 1.0 mmol / g, a hydroxyl content of 2.0 mmol / g, and a specific surface area of ​​750 m 2 / g.

[0061] Comparative Example 1

[0062] Compared with Example 1, the difference in Comparative Example 1 is that styrene is 70 g and divinylbenzene is 15 g.

[0063] Comparative Example 2

[0064] Compared with Example 1, Comparative Example 2 replaces ferric chloride with an equal amount of zinc chloride, and the rest is the same as Example 1.

[0065] Test example

[0066] The properties of the adsorbents prepared in Examples 1-5 and Comparative Examples 1-2 were determined using the following method:

[0067] Adsorption performance: 10 mL of plasma solution containing indoxyl sulfate, p-cresol sulfate, β2-microglobulin, vitamin B, creatinine, and pentobarbital sodium was added to 1 mL each of the adsorbent prepared in the above examples and comparative examples and the adsorbent of a commercially available product. The mixture was sealed and shaken on a shaker at 37°C for 2 hours for adsorption. After the adsorption was completed, the changes in each toxin and total protein were measured, and the adsorption rate of each toxin by the adsorbent was calculated based on the concentration difference before and after adsorption. The above experiment was repeated three times and the average value was taken. The results are shown in Table 1.

[0068] Blood compatibility: The adsorbent was soaked in physiological saline for 30 minutes, and the surface moisture was filtered with a sand core funnel. 0.5 g of adsorbent was weighed and added to 2 mL of fresh human blood provided by a volunteer (with EDTA-K2 anticoagulant). The blood was placed in a 37°C water bath and kept constant for 2 hours. The changes in blood cells were measured on a hematology analyzer. The compatibility of the adsorbents prepared in Examples 1-5 and Comparative Examples 1-2 and the commercially available adsorbent was measured. The above experiment was repeated three times and the average value was taken. The results are shown in Table 1.

[0069] Table 1 Properties of adsorbents in Examples 1-5 and Comparative Examples 1-2

[0070]

[0071] As can be seen from Table 1, compared with commercially available products, the adsorbents prepared in Examples 1-4 of the present invention have significantly reduced adhesion to red blood cells, white blood cells, and platelets, and significantly reduced adsorption of total protein. This not only improves blood compatibility, but also significantly improves the adsorption of toxins in uremic patients, especially having a significant clearance effect on protein-bound toxins.

[0072] Compared with Example 1, Example 5 did not undergo chlorination and hydrolysis. As a result, the adsorbent prepared in Example 5 had lower adsorption performance than that in Example 1, and the reduction rate of red blood cells, white blood cells, and platelets in the blood was higher than that in Example 1. This indicates that the adsorbent obtained by chlorinating and hydrolyzing the resin obtained by polymerization of styrene, acrylic acid, and divinylbenzene has good adsorption performance and a low reduction rate of red blood cells, white blood cells, and platelets in the blood.

[0073] Compared to Example 1, Comparative Example 1 varied the mass of styrene and divinylbenzene. The resulting adsorbent exhibited lower performance than Example 1, demonstrating that limiting the mass ratio of styrene, acrylic acid, and divinylbenzene in the adsorbent can improve adsorbent performance. Comparative Example 2, in contrast to Example 1, replaced ferric chloride with an equal amount of zinc chloride. This demonstrates that the present invention, through chlorination with ferric chloride, improves adsorption performance and reduces the decrease in red blood cells, white blood cells, and platelets in the blood.

[0074] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A heparin-capturing uremic toxin adsorbent, characterized in that: The raw materials of the adsorbent include styrene, acrylic acid and divinylbenzene; The adsorbent is obtained by polymerization of styrene, acrylic acid and divinylbenzene, wherein the mass ratio of styrene, acrylic acid and divinylbenzene is 5-20:5-15:70-90; The preparation method of the heparin-captured uremic toxin adsorbent is as follows: S1, mixing styrene, acrylic acid, divinylbenzene, a porogen and an initiator to obtain an oil phase; S2, mixing polyvinyl alcohol, sodium chloride and water to obtain an aqueous phase; S3, mixing the oil phase and the water phase for reaction, and removing the porogen to obtain resin I; S4, after resin I is subjected to chlorination reaction, resin II is obtained; S5, hydrolyzing resin II to obtain an adsorbent; The chlorination reaction in S4 is as follows: adding resin I to chloromethyl ether, swelling at 30-45°C for 2-24 hours, adding ferric chloride and reacting at 42-45°C for 2-24 hours; the mass ratio of resin I to chloromethyl ether is 1:3-7; The hydrolysis in S5 is performed by adding resin II into a sodium hydroxide solution for hydrolysis; the mass ratio of the sodium hydroxide solution to resin II is 2-6:1; the concentration of the sodium hydroxide solution is 1-3 mol / L; the hydrolysis in S5 is performed at 70-90° C. for 12-24 hours.

2. A heparin-capturing uremic toxin adsorbent according to claim 1, characterized in that: The mass concentration of polyvinyl alcohol in the S2 aqueous phase is 0.5%-2%, and the mass concentration of sodium chloride is 3%-8%.

3. The heparin-capturing uremic toxin adsorbent according to claim 1, characterized in that: The mass ratio of the water phase to the oil phase in S3 is 2-4:

1.

4. The heparin-capturing uremic toxin adsorbent according to claim 1, characterized in that: The reaction temperature in S3 is 78-90° C., and the reaction time is 4-12 h.

5. The heparin-capturing uremic toxin adsorbent according to claim 1, characterized in that: The porogen in S1 is a mixture of a first porogen and a second porogen, the first porogen is an alkane or an aromatic hydrocarbon, and the second porogen is an alcohol or an ester; the first porogen accounts for 50%-70% of the total mass of the porogen.

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