A method for modifying a blood purification adsorption material

Abstract

The application discloses a blood purification adsorption material, a treatment method and application. The interpenetrating crosslinking method is to perform interpenetrating crosslinking on adsorbents in the adsorption material, so as to form an interpenetrating network polymer structure, and a reaction system of the interpenetrating crosslinking includes sodium p-styrenesulfonate, hydroxyethyl methacrylate, glycidyl methacrylate, an initiator and a solvent. The size of a micro-phase separation structure formed between film layers of the interpenetrating network polymer structure is between dozens of nanometers and 100 nanometers, which can be beneficial to blocking of toxin molecules such as inflammatory cytokines in blood by the adsorption material.

Description

Technical Field

[0001] This invention relates to the field of medical materials technology, and in particular to a method for modifying a blood purification adsorption material. Background Technology

[0002] Endotoxemia typically leads to fatal septic shock, multiple organ failure, and disseminated intravascular coagulation, with an extremely high mortality rate. Conditions that may cause endotoxemia include: severe trauma, infection, and other stressful situations; systemic reticuloendothelial system dysfunction, decreased immune function, and excessive endotoxin absorption by the intestines exceeding the body's clearance capacity; gastrointestinal mucosal ischemia, necrosis, and barrier disruption, resulting in the release of large amounts of endotoxins into the bloodstream; endotoxins absorbed in the intestines entering the systemic circulation directly via collateral circulation due to liver dysfunction; and infections of certain tissues and organs causing exogenous endotoxins to enter the bloodstream.

[0003] Clinically, extracorporeal blood circulation can be used with blood purification consumables such as hemoperfusion devices to remove medium- and large molecular toxins, including inflammatory cytokines, from the patient's blood, thereby treating endotoxemia. Current technologies often require modification of the adsorbent. Coating materials typically include PVB and collodion, such as improving blood compatibility through physical coating or enhancing adsorption capacity through chemical loading. However, physically coated membranes have poor stability and are prone to detachment, which can easily lead to new complications. Chemical loading modification can slightly impair the properties of the carrier material, resulting in reduced purification and adsorption efficiency. Summary of the Invention

[0004] The purpose of this invention is to provide a method for modifying blood purification adsorption materials to solve one or more technical problems existing in the prior art, and at least provide a beneficial option or create conditions.

[0005] The first aspect of this invention provides a method for interpenetrating crosslinking of adsorbent materials.

[0006] A second aspect of the present invention provides an adsorption material.

[0007] A third aspect of the present invention provides the application of the adsorbent material in a blood purification medical device.

[0008] The first aspect of this invention provides an interpenetrating crosslinking method for crosslinking an adsorbent in an adsorbent material to form an interpenetrating network polymer structure. The reaction system for the interpenetrating crosslinking includes sodium styrene sulfonate, hydroxyethyl methacrylate (HEMA), glycidyl methacrylate (GMA), an initiator, and a solvent. The treated adsorbent and the support form an interpenetrating network polymer (IPN). The IPN is formed by the continuous interpenetration of networks obtained by crosslinking crosslinked polymer I and crosslinked polymer II. IPN differs from graft copolymers because no chemical bonds are formed between polymers I and II in the IPN; simultaneously, IPN also differs from compatible blends, as it contains separate phases with micro-regions of phase separation as small as tens to hundreds of nanometers.

[0009] In some embodiments of the first aspect of the present invention, the adsorbent is selected from one of polystyrene divinylbenzene microspheres, polymethacrylate microspheres, resin-based carbonized resin, pitch-based carbonized resin, agarose microspheres, cellulose microspheres, or polyethylene porous sheets.

[0010] In some embodiments of the first aspect of the present invention, the initiator is an inorganic peroxide compound.

[0011] In some embodiments of the first aspect of the present invention, the initiator is selected from at least one of potassium persulfate, sodium persulfate, and ammonium persulfate.

[0012] In some embodiments of the first aspect of the present invention, the solvent is methanol or ethanol.

[0013] In some embodiments of the first aspect of the present invention, the molar ratio of sodium p-styrene sulfonate to hydroxyethyl methacrylate is 1:(2-5). Preferably, the molar ratio of sodium p-styrene sulfonate to hydroxyethyl methacrylate is 1:2.0, 1:2.5, 1:3.0, 1:3.5, 1:4.0, 1:4.1, 1:4.2, 1:4.3, 1:4.4, 1:4.5, 1:4.6, 1:4.7, 1:4.8, 1:4.9, or 1:5.0.

[0014] In some embodiments of the first aspect of the present invention, the specific interpenetrating crosslinking method includes the following steps: 1) obtaining an adsorbent;

[0015] 2) Add solvent to the adsorbent, and add sodium p-styrene sulfonate, hydroxyethyl methacrylate, glycidyl methacrylate and initiator respectively, and stir to react;

[0016] 3) After the reaction is complete, wash with solvent and water respectively to obtain interpenetrating network polymerized adsorbent.

[0017] In some embodiments of the first aspect of the invention, the interpenetrating network polymeric adsorbent can be further modified, with the modifying material selected from polymyxin B sulfate, polylysine, or polyethyleneimine. The further modified interpenetrating network polymeric adsorbent can significantly improve the endotoxin removal rate.

[0018] The adsorbent material provided in the second aspect of this invention is prepared by the interpenetrating crosslinking method described in the first aspect of this invention. The obtained adsorbent material exhibits good scavenging effects on inflammatory cytokines.

[0019] A third aspect of the present invention provides the application of the adsorbent material in a blood purification medical device. The blood purification medical device includes a dialyzer or a hemofilter.

[0020] Porous materials such as adsorption resins and carbonized resins typically have cross-linked structures with few modifiable groups. HEMA copolymers, on the other hand, are generally coated through physical processes, making them prone to detachment during blood purification. This technology utilizes a free radical polymerization chemical reaction to achieve both the synthesis and coating of the copolymer film in one step. This allows the copolymer to become entangled and cross-linked within the porous structure of the adsorbent, forming an interpenetrating polymer network structure with the adsorbent carrier. This makes the HEMA copolymer film less prone to detachment and provides possibilities for subsequent modification of the adsorbent carrier. The interpenetrating polymer network coating enhances the hydrophilicity of the adsorbent and improves its blood compatibility.

[0021] There are no chemical bonds between the cross-linked HEMA copolymer film and the adsorbent carrier; their movement is limited only by the cross-linked structure of the interpenetrating network. Furthermore, the interpenetrating network polymer structure allows the sulfonic acid-containing cross-linked HEMA copolymer film to be distributed throughout the internal and external structure of the adsorbent, improving the blood compatibility of the adsorbent carrier and thus enhancing the safety of the adsorbent material.

[0022] The microphase separation structure formed between the adsorbent carrier and the cross-linked HEMA copolymer membrane containing sulfonic acid groups has a size between tens and hundreds of nanometers, which can help the adsorbent material block toxic molecules such as inflammatory cytokines in the blood.

[0023] This technology can cross-link various forms of adsorbents used for blood purification (such as cross-linked microspheres and porous plates) into interpenetrating networks. By utilizing the structure of the interpenetrating network polymer, its blood compatibility can be improved, thereby enhancing the safety of blood purification materials. Detailed Implementation

[0024] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to specific examples. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] Unless otherwise specified in the following examples, the techniques or conditions described in the literature in this field or in accordance with the product instructions shall apply. All reagents or instruments without a specified manufacturer are commercially available conventional products.

[0026] The specific test materials include:

[0027] Example 1: Preparation of interpenetrating network polymeric adsorbent

[0028] 1-1. Preparation of adsorbent materials composed of interpenetrating network crosslinked hydroxyethyl methacrylate copolymer

[0029] In a resin containing polystyrene-divinylbenzene adsorbent (adsorbent S0, specific surface area ≥600 m²), 2 In a 250 mL alcohol solution containing approximately 30 g of sodium p-styrene sulfonate (pore size 3–20 nm), 3.4 g of sodium p-styrene sulfonate and 6.9 g of hydroxyethyl methacrylate were added, followed by 0.1 g of potassium persulfate initiator and 0.08 g of glycidyl methacrylate (GMA). The mixture was stirred at 60 °C for 5 hours.

[0030] After the reaction is complete, wash with alcohol and water for injection to obtain adsorbent S1.

[0031] Example 2: Modification of interpenetrating network polymeric adsorbent

[0032] 2-1. Modification of polymyxin B sulfate.

[0033] Take the adsorbent S1 obtained in step 1-1, add 50 mL of 3% polymyxin B sulfate solution, and react at 35±5℃ for 3±1 hours.

[0034] After the reaction is complete, wash with alcohol and water for injection to obtain adsorbent S2.

[0035] 2-2. Polylysine modification.

[0036] Take the adsorbent S1 obtained in step 1-1, add 50 mL of a 5% polylysine solution, and react at 35±5℃ for 3±1 hours.

[0037] After the reaction is complete, wash with alcohol and water for injection to obtain adsorbent S3.

[0038] 2-3. Polyethyleneimine modification.

[0039] Take the adsorbent S2 obtained in step 1-1, add 50 mL of a 3% polyethyleneimine solution, and react at 35±5℃ for 3±1 hours.

[0040] After the reaction was complete, the solution was washed with alcohol and water for injection to obtain adsorbent S4.

[0041] Comparative Example 1: Preparation of Physically Coated Adsorbents

[0042] 1. Synthesis of cross-linked hydroxyethyl methacrylate copolymer.

[0043] A random copolymer of sodium p-styrene sulfonate and hydroxyethyl methacrylate was synthesized by free radical polymerization. 25.6 g of sodium p-styrene sulfonate and 52 g of hydroxyethyl methacrylate were added to 250 mL of alcohol solution, followed by 0.1 g of potassium persulfate initiator and 0.08 g of glycidyl methacrylate (GMA). The mixture was stirred at 60 °C for 5 hours. After the reaction was complete, the polymerization solution was added to water to precipitate the copolymer.

[0044] 2. Physical encapsulation.

[0045] A 1% coating solution was prepared by dissolving the cross-linked hydroxyethyl methacrylate copolymer in an alcohol solution. 1 g of polystyrene-divinylbenzene adsorption resin was immersed in 10 mL of the coating solution and dried at 25°C for 24 hours.

[0046] After coating, wash with water for injection to obtain adsorbent S5.

[0047] Experiment 1: Static Adsorption of Inflammatory Cytokines

[0048] Take a pyrogen-free test tube and add 0.25 mL of each of the adsorbents S0 to S5. Then add 2.5 mL of plasma containing 108 pg / mL of the inflammatory cytokines interleukin-6 (IL-6) and 383 pg / mL of tumor necrosis factor-α (TNF-α). Shake and adsorb for 2 hours (temperature 37℃, shaking rate 100±10 rpm). Then measure the concentrations of IL-6, TNF-α and albumin before and after adsorption, and calculate the scavenging rate of the adsorbent.

[0049] Table 1. Scavenging rates of several adsorbents for IL-6 and TNF-α

[0050]

[0051] As shown in Table 1, the physically coated adsorbent S5 exhibited a clearance rate of 50.93% for IL-6 and 34.99% for TNF-α, significantly lower than the original adsorbent S0's 60.56% and 40.73%, respectively, demonstrating a marked decrease in its clearance rate of inflammatory cytokines. In contrast, the adsorbents S1 to S4, modified with interpenetrating network crosslinking, did not show a significant decrease in their clearance rates of inflammatory cytokines. This indicates that the crosslinking and interpenetrating method provided in this technical solution can prevent a decline in the performance of the adsorbent materials. However, the adsorption performance for larger molecular weight albumin was slightly reduced, which can decrease nutrient loss, as shown in Table 2.

[0052] Table 2. Scavenging rate of albumin by several adsorbents

[0053]

[0054] Experimental Example 2: Static Adsorption of Endotoxins

[0055] In patients with high endotoxin levels, the endotoxin concentration is generally less than 1 EU / mL. Therefore, the initial adsorption concentration was set at 1 EU / mL in this experiment. 0.05 g of the prepared adsorbent was added to each pyrogen-free test tube, followed by 1.5 mL of a solution containing 1 EU / mL of endotoxin. The tubes were shaken for 2 hours (37℃, shaking rate 100±10 rpm). The endotoxin concentration after adsorption was then measured using a chromogenic matrix Limulus amebocyte lysate (LAL) reagent kit, and the scavenging rate of the adsorbent was calculated. The results are shown in Table 3. It was found that after modification with polymyxin B sulfate, polylysine, or polyethyleneimine, adsorbent S1 exhibited better adsorption of endotoxins, resulting in a higher scavenging rate.

[0056] Table 3. Scavenging rates of several adsorbents for endotoxins

[0057]

[0058] As can be seen from the data in the table above, the cross-linked adsorbent material modified with polylysine has a significantly improved endotoxin removal rate compared to ordinary cross-linked adsorbent materials.

[0059] Experimental Example 3, Hemolysis Experiment

[0060] The hemolysis rate of the adsorbent was determined (the hemolysis test was performed according to GB / T16886.4-2003 "Biological evaluation of medical devices - Part 4: Selection of blood interaction tests" and GB / T16175-2008 "Biological evaluation test methods for medical organosilicon materials").

[0061] Triple replicates were prepared for each combination. For the sample group, 5g of the test sample was added to each tube, followed by 10mL of sodium chloride injection. For the negative control group, 10mL of sodium chloride injection was added to each tube. For the positive control group, 10mL of distilled water was added to each tube. Three replicates were performed for each group. All tubes were placed in a constant temperature water bath at (37±1)℃ for 30 minutes. Then, 0.2mL of diluted rabbit blood was added to each tube, gently mixed, and kept in the (37±1)℃ water bath for another 60 minutes. The liquid in the tubes was poured out and centrifuged at 800g for 5 minutes. The supernatant was transferred to a cuvette, and the absorbance was measured at 545nm using a spectrophotometer. The absorbance of the sample combination and control group was taken as the average of the three tubes. The absorbance of the negative control tube should not exceed 0.03, and the absorbance of the positive control tube should be 0.8±0.3; otherwise, the test should be repeated.

[0062]

[0063] Where A represents the absorbance of the sample group;

[0064] B – Absorbance of the negative control group;

[0065] C – Absorbance of the positive control group.

[0066] Table 4. Hemolysis rate of several adsorbents

[0067]

[0068] The results are shown in Table 4. The hemolysis rate of the adsorbent is less than 1%, which is far less than the national standard requirement of ≤5%. This proves that the interpenetrating crosslinking method provided by this invention is safe and reliable, and the product obtained meets the relevant national standards.

[0069] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

Claims

1. A method for interpenetrating crosslinking of a blood purification adsorbent material, characterized in that, The adsorbent in the adsorbent material is cross-linked to form an interpenetrating network polymer structure. The cross-linking reaction system includes sodium p-styrene sulfonate, hydroxyethyl methacrylate, glycidyl methacrylate, an initiator, and a solvent. The adsorbent is selected from one of polystyrene divinylbenzene microspheres, polymethacrylate microspheres, resin-based carbonized resin, agarose microspheres, cellulose microspheres, or polyethylene porous sheets. The molar ratio of sodium p-styrene sulfonate to hydroxyethyl methacrylate is 1:(2~5).

2. The interpenetrating crosslinking method according to claim 1, characterized in that, The initiator is an inorganic peroxide compound.

3. The interpenetrating crosslinking method according to claim 2, characterized in that, The initiator is selected from at least one of potassium persulfate, sodium persulfate, and ammonium persulfate.

4. The interpenetrating crosslinking method according to claim 1, characterized in that, The solvent is methanol or ethanol.

5. The interpenetrating crosslinking method according to any one of claims 1 to 4, characterized in that, Including the following steps: 1) Obtain the adsorbent; 2) Add solvent to the adsorbent, and add sodium p-styrene sulfonate, hydroxyethyl methacrylate, glycidyl methacrylate and initiator respectively, and stir to react; 3) After the reaction is complete, wash with solvent and water respectively to obtain interpenetrating network polymeric adsorbent.

6. The interpenetrating crosslinking method according to claim 5, characterized in that, It also includes the following steps: 4) Modify the interpenetrating network polymeric adsorbent, wherein the modifying material is selected from polymyxin B sulfate, polylysine or polyethyleneimine.

7. An adsorbent material, characterized in that, The adsorbent material is prepared by the interpenetrating crosslinking method according to any one of claims 1 to 6.

8. The application of the adsorbent material according to claim 7 in a blood purification medical device, characterized in that, The blood purification medical device includes a dialyzer or a blood filter.

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