A blood purification microsphere adsorbent and its application

Abstract

The present invention discloses a blood purification microsphere adsorbent. The adsorbent carrier comprises carboxylated polyimide resin microspheres having a carboxyl group content of 0.1 to 0.5 mol / 100 g. The adsorbent carrier couples an adsorption ligand via carboxyl groups, wherein the diameter of the carboxylated polyimide resin microspheres ranges from 50 to 200 μm. This solution utilizes a method in which polyimide resin is first prepared into resin microspheres, followed by surface hydrolysis to form carboxyl groups. This method yields resin microspheres with diameters of several hundred microns, which are less prone to agglomeration. Compared to conventional adsorbent carriers, these microspheres exhibit high mechanical strength, structural stability, excellent heat resistance, and significantly improved biocompatibility, meeting clinical application requirements.

Description

Technical Field

[0001] The present invention relates to a blood purification material in the medical field, and in particular to a blood purification microsphere adsorbent and application thereof. Background Art

[0002] Blood purification is a new clinical treatment method that has emerged in recent years. It primarily achieves therapeutic goals by removing pathogenic substances and metabolic toxins from the blood. Immunoadsorption therapy is a key method of blood purification. Its characteristic is that it establishes a branch of the human blood circulation outside the body, passing blood through a special adsorbent to absorb and remove pathogenic substances from the blood, thereby purifying the internal environment and treating diseases. The key to immunoadsorption therapy lies in the immunoadsorbent.

[0003] Adsorbents consist of a carrier component, a ligand component, and the connection between them. The core of the adsorption reaction with the pathogenic agent is the ligand with immunosorbent activity, which adsorbs pathogenic substances through bioaffinity and hydrophobic interactions with the adsorbent. Adsorbent carriers serve as the supporting framework for the ligand and can typically be made of multifunctional carbon materials (activated carbon), synthetic resins (polystyrene resin, silica gel, polyvinyl alcohol resin, polyurethane resin), and polysaccharides (chitosan, cellulose, agarose, etc.).

[0004] On the one hand, the commonly used adsorbent carriers have certain defects, such as polystyrene resin carriers and agarose carriers. Polystyrene resin carriers have high mechanical strength, stable physical / chemical properties, and controllable structure. However, the resin is highly hydrophobic and has poor blood compatibility, requiring surface coating with hydrophilic materials or hydrophilic modification. Agarose carriers have good biocompatibility, but poor mechanical stability and acid and alkali resistance. On the other hand, the above carriers need to be pre-activated during use before they can be smoothly coupled with the ligand. The coupling method is complex and the coupling effect is poor. The above problems limit the preparation and application of commonly used immunosorbent carriers.

[0005] Polyimide is a class of aromatic heterocyclic polymer materials containing imide chain links. It has outstanding heat resistance and excellent mechanical properties and has broad application prospects. Fiber membranes or microspheres made from polyimide are currently mostly used in the field of microelectronics, as well as catalysis, encapsulation, controlled release and fillers. Currently, polyimide resin microspheres are mostly made by polymerizing diamine and dianhydride monomers to generate a polyamic acid precursor solution, and then reverse emulsion polymerization or electrospinning is used to obtain polyimide resin microspheres. The resin microspheres prepared by this method have a small particle size, mostly nanometers or tens of microns. They are easy to agglomerate when used and are generally not considered as carriers for preparing adsorbents. When the particle size of the prepared resin microspheres is large, the resin microspheres are prone to collapse, which limits the application of polyimide resin microspheres as blood purification adsorbent carriers. Summary of the Invention

[0006] The purpose of the present invention is to overcome at least one deficiency of the prior art and provide a blood purification microsphere adsorbent and its application.

[0007] The technical solution adopted by the present invention is:

[0008] In a first aspect, the present invention provides a blood purification microsphere adsorbent, wherein the adsorbent carrier is a carboxylated polyimide resin microsphere, and the adsorbent carrier is coupled to an adsorption ligand via a carboxyl group;

[0009] The carboxyl content of the carboxylated polyimide resin microspheres is 0.1 to 0.5 mol / 100 g, and the diameter of the carboxylated polyimide resin microspheres is 50 to 200 um.

[0010] In some examples, the preparation method of the carboxylated polyimide resin microspheres is: immersing the polyimide resin microspheres in an alkaline catalyst solution for hydrolysis, reacting for 5 to 10 hours, and then filtering, washing, and drying to obtain the carboxylated polyimide microspheres.

[0011] In some examples, the alkaline catalyst is selected from at least one of sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, lithium hydroxide, tetramethylammonium hydroxide, and tetraethylammonium hydroxide.

[0012] In some examples, the mass concentration of the alkaline catalyst is 5-10%.

[0013] In some examples, the ligand is selected from one or more of protein A, phenylalanine, tryptophan, polymyxin B, and antibodies.

[0014] In some examples, the preparation method of the polyimide resin microspheres is:

[0015] 1) Adding a polyimide resin to a strong polar solvent and stirring for 10 to 24 hours to completely dissolve it, and then adding a water-soluble porogen to obtain a polyimide precursor solution;

[0016] 2) The polyimide precursor solution is electrospun, and then washed, filtered, and dried to obtain polyimide resin microspheres.

[0017] In some examples, the highly polar solvent is selected from at least one of dimethyl sulfoxide, N-methyl-2-pyrrolidone, N,N-dimethylformamide and N,N-dimethylacetamide.

[0018] In some examples, the water-soluble porogen is selected from one or more of polyethylene imine, polyethylene glycol 800, polyethylene glycol 1000, polyethylene glycol 2000, polyvinyl pyrrolidone, polyacrylic acid, polyvinyl alcohol, Tween-20, Tween-60, and Tween-80.

[0019] In some examples, the proportions of the components of the polyimide precursor solution are: 10-50 parts of polyimide resin, 1-10 parts of water-soluble porogen, and 100-300 parts of strong polar solution.

[0020] The second aspect is the use of the blood purification microsphere adsorbent described in the first aspect of the present invention in the preparation of blood purification materials.

[0021] The beneficial effects of the present invention are:

[0022] This scheme uses a method in which polyimide resin is first prepared into resin microspheres, and then the surface is hydrolyzed to form carboxyl groups. Resin microspheres with diameters of several hundred microns can be obtained. These microspheres are not easy to agglomerate, and ligands can be further coupled to the surface to prepare adsorbents. Compared with agarose carriers, they have high mechanical strength, stable structure, and good heat resistance. Compared with polystyrene resins, their biocompatibility is significantly improved. The carboxyl groups can be grafted with different ligands to achieve multifunctional adsorbents. DETAILED DESCRIPTION

[0023] A blood purification microsphere adsorbent, wherein the adsorbent carrier is a carboxylated polyimide resin microsphere, and the adsorbent carrier is coupled to an adsorption ligand via a carboxyl group;

[0024] The carboxyl content of the carboxylated polyimide resin microspheres is 0.1 to 0.5 mol / 100 g, and the diameter of the carboxylated polyimide resin microspheres is 50 to 200 um.

[0025] Carboxylated polyimide resin microspheres with a diameter of 50 to 200 μm can be directly prepared by electrospinning and are not easy to agglomerate. The microspheres contain a large number of carboxyl groups on the surface and inside, which is conducive to coupling more ligands and achieving better adsorption.

[0026] In some examples, the preparation method of the carboxylated polyimide resin microspheres is: immersing the polyimide resin microspheres in an alkaline catalyst solution for hydrolysis, reacting for 5 to 10 hours, and then filtering, washing, and drying to obtain the carboxylated polyimide microspheres.

[0027] The alkaline catalyst can promote the polyimide resin to expose the carboxyl group. In some examples, the alkaline catalyst is selected from at least one of sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, lithium hydroxide, tetramethylammonium hydroxide, and tetraethylammonium hydroxide.

[0028] In some examples, the mass concentration of the alkaline catalyst is 5-10%, which is more conducive to obtaining an appropriate hydrolysis rate.

[0029] The ligand is one that can react and couple with a carboxyl group. Alternatively, the ligand may be activated so that the activated ligand can undergo a coupling reaction with the carboxyl group. In some embodiments, the ligand is selected from one or more of protein A, phenylalanine, tryptophan, polymyxin B, and antibodies. These ligands are commonly used in blood purification.

[0030] In some examples, the preparation method of the polyimide resin microspheres is:

[0031] 1) Adding a polyimide resin to a strong polar solvent and stirring for 10 to 24 hours to completely dissolve it, and then adding a water-soluble porogen to obtain a polyimide precursor solution;

[0032] 2) The polyimide precursor solution is electrospun, and then washed, filtered, and dried to obtain polyimide resin microspheres.

[0033] In some examples, the highly polar solvent is selected from at least one of dimethyl sulfoxide, N-methyl-2-pyrrolidone, N,N-dimethylformamide and N,N-dimethylacetamide.

[0034] In some examples, the water-soluble porogen is selected from one or more of polyethylene imine, polyethylene glycol 800, polyethylene glycol 1000, polyethylene glycol 2000, polyvinyl pyrrolidone, polyacrylic acid, polyvinyl alcohol, Tween-20, Tween-60, and Tween-80. The specific porogen can be adjusted accordingly based on the pore-forming effect to obtain satisfactory performance.

[0035] In some examples, the proportions of the components of the polyimide precursor solution are: 10-50 parts of polyimide resin, 1-10 parts of water-soluble porogen, and 100-300 parts of strong polar solution.

[0036] The following disclosure provides many different embodiments or examples for implementing different solutions of the present invention. The preparation method of the blood purification microsphere adsorbent in the embodiment of the present invention is as follows:

[0037] 1. Take an appropriate amount of polyimide resin powder, add it to a strong polar solvent, ultrasonically disperse it for 10 minutes, stir it at room temperature for 10-24 hours until it is completely dissolved, and add a certain amount of water-soluble porogen to obtain a uniform solution;

[0038] 2. Pour the above uniform solution into a syringe for electrospinning. The spinning voltage is 26KV and the spinning solution flow rate is 5ml / h. The spinning solution is dripped into the receiving liquid to form a large number of droplets. After the droplets are stable, they are filtered through a sand core funnel to obtain yellow particles. The obtained particles are washed with deionized water several times and dried in a vacuum drying oven for 2h to obtain resin microspheres.

[0039] 3. Prepare a 5-10% alkaline catalyst solution, soak the resin microspheres obtained in step (2) in the solution, stir and react for 5-10 hours, filter, wash and dry to obtain carboxylated polyimide microspheres.

[0040] The reagents and reaction conditions in each example are shown in Table 1 below:

[0041] Table 1

[0042] Example solvent porogen Mass ratio of each component (polyimide: porogen: solvent) Catalyst solution mass concentration Reaction time (h) 1 NMF Polyethyleneimine 20：5：150 NaOH 10% 5 2 NMP Tween-60 10：1：100 KOH 5% 8 3 DMSO Polyethylene glycol 800 50：10：300 Sodium carbonate 8% 12 4 NMF polyacrylic acid 30：7：200 Potassium carbonate 10% 6

[0043] Preparation of Protein A Immunosorbent

[0044] In a 500 mL reaction vessel, add 10 g of the carboxylated polyimide resin microspheres from Example 1 and 150 mL of 0.1 mol / L borate buffer. The pH of the system is controlled at 7.5 to 8.5. Then, add 14 g of genetically engineered recombinant protein A and react at 37°C for 20 h. The reaction is terminated and the filler is rinsed with approximately 10 volumes of injection water. After rinsing, 200 mL of 0.2 M ethanolamine solution is added to block unreacted carboxyl groups. The reaction is continued at 20°C for 10 h. After the reaction is complete, rinse with plenty of injection water and store in a solution containing a preservative.

[0045] 1g of adsorbent was added to thawed plasma at a ratio of 1:4. The sample was placed in a 37°C water bath in a constant-temperature shaker at 60 rpm for 2 hours. After adsorption, the upper plasma layer was removed and sent for testing. The adsorption capacity of the prepared protein A immunosorbent for IgG was measured to be 46 mg / g.

[0046] Preparation of tryptophan adsorbent

[0047] Soak the carboxylated polyimide resin microspheres from Example 2 in anhydrous tetrahydrofuran 3-5 times. Add 10 g of the polyimide resin microspheres to a 500 mL reaction vessel, followed by 0.2 g of tryptophan and 100 mL of anhydrous pyridine. React at 30°C for 10 h. Wash the adsorbent with water and store at 4°C.

[0048] 1g of adsorbent was added to thawed plasma at a ratio of 1:4. The sample was placed in a 37°C water bath shaker at 60 rpm for 2 hours. After adsorption, the upper plasma layer was removed and tested. The adsorption capacity of the prepared tryptophan adsorbent for IgG was measured to be 40mg / g.

[0049] From the adsorption amount of IgG in Examples 1 and 2, it can be seen that the blood purification adsorbent prepared by using polyimide resin microspheres as a carrier has an adsorption amount of pathogenic factors that meets the requirements of clinical application.

[0050] Resin carrier performance comparison test

[0051] The performance of the carboxylated polyimide resin microspheres of Examples 1 and 3 was tested and compared with common agarose microspheres and polystyrene resin. The results are shown in Table 2.

[0052] Table 2

[0053] sample Water contact angle (°) Hemolysis rate (%) Example 1 60.8 0.35 Example 3 65.2 0.23 Agarose microspheres 47.5 0.12 polystyrene resin 85.2 4.78

[0054] It can be seen that the water contact angle and hemolysis rate data of the prepared polyimide resin microsphere carrier are comparable to those of agarose microspheres, which are significantly better than those of polystyrene resin. The mechanical strength of the microspheres is higher than that of agarose microspheres, and they have excellent performance.

[0055] The above is a further detailed description of the present invention and should not be considered as a limitation on the specific implementation of the present invention. For those skilled in the art, simple deductions or substitutions that do not depart from the concept of the present invention are within the scope of protection of the present invention.

Claims

1. A method for preparing a blood purification microsphere adsorbent, characterized in that: The adsorbent carrier is a carboxylated polyimide resin microsphere, and the adsorbent carrier is coupled to the adsorption ligand via the carboxyl group; wherein: The preparation method of the polyimide resin microspheres is: 1) adding a polyimide resin to a strong polar solvent and stirring for 10 to 24 hours to completely dissolve it, then adding a water-soluble porogen to obtain a polyimide precursor solution, wherein the weight ratio of the components of the polyimide precursor solution is: 10 to 50 parts of polyimide resin, 1 to 10 parts of water-soluble porogen, and 100 to 300 parts of a strong polar solvent, wherein the strong polar solvent is selected from at least one of dimethyl sulfoxide, N-methyl-2-pyrrolidone, N,N-dimethylformamide, and N,N-dimethylacetamide; 2) electrospinning the polyimide precursor solution, followed by washing, filtering, and drying to obtain polyimide resin microspheres; The carboxyl content of the carboxylated polyimide resin microspheres is 0.1 to 0.5 mol / 100 g, the diameter of the carboxylated polyimide resin microspheres is 50 to 200 μm, and the preparation method of the carboxylated polyimide resin microspheres is as follows: The polyimide resin microspheres are immersed in an alkaline catalyst solution for hydrolysis, reacted for 5 to 10 hours, and then filtered, washed, and dried to obtain carboxylated polyimide resin microspheres. The alkaline catalyst is selected from at least one of sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, lithium hydroxide, tetramethylammonium hydroxide, and tetraethylammonium hydroxide. The mass concentration of the alkaline catalyst solution is 5 to 10%.

2. The preparation method according to claim 1, characterized in that The ligand is selected from one or more of protein A, phenylalanine, tryptophan, polymyxin B, and antibodies.

3. The preparation method according to claim 1, characterized in that The water-soluble porogen is selected from one or more of polyethylene imine, polyethylene glycol 800, polyethylene glycol 1000, polyethylene glycol 2000, polyvinyl pyrrolidone, polyacrylic acid, polyvinyl alcohol, Tween-20, Tween-60, and Tween-80.

4. Use of the blood purification microsphere adsorbent prepared by the preparation method according to any one of claims 1 to 3 in the preparation of blood purification materials.