A method for grafting polymyxin onto the surface of polystyrene

Abstract

The present invention provides a method for grafting polymyxin onto the surface of polystyrene. Using chloromethylated polystyrene as the carrier substrate, it successively undergoes a nucleophilic substitution reaction with diallylamine, an amphoteric ionizing reaction with an amphoteric ionizing reagent, a graft copolymerization reaction with an amphoteric ion monomer containing a glycidyl group and a gemini amphoteric ion crosslinker containing a glycidyl group, and an amino ring-opening reaction with polymyxin, so as to achieve the grafting of polymyxin onto the surface of polystyrene. According to the technical solution of the present invention, the surface polymyxinylated polystyrene prepared not only has specific adsorption properties for blood endotoxin, but also has excellent hydrophilicity, blood compatibility, anti-coagulation function, and anti-protein non-specific adhesion characteristics.

Description

Technical Field

[0001] The present invention relates to a method for preparing a medical functional polymer material, and particularly to a method for grafting polymyxin onto the surface of polystyrene. After grafting polymyxin onto the surface of polystyrene according to the present invention, in addition to having specific adsorption properties for blood endotoxin, it also has excellent hydrophilicity, blood compatibility, anti-coagulation function, and anti-protein non-specific adhesion properties, belonging to the field of functional polymer materials. Background Art

[0002] Since Japanese scholars used polystyrene fiber bonded and immobilized polymyxin B as an adsorbent material to remove endotoxin in blood by hemoperfusion for the treatment of endotoxemia, it has played an important role in improving the quality of life and prolonging the life of patients. For this reason, scholars from many countries have scrambled to conduct extensive research and development in various aspects for decades and obtained some beneficial effects: (1) The hemoperfusion adsorbent material consists of a carrier and a ligand bonded to the surface of the carrier. (2) The basic characteristics of the substrate used as the carrier are excellent mechanical properties, chemical structure stability, hydrophilicity, biocompatibility, no blood coagulation phenomenon, no biological toxicity and variability, etc., and the carrier substrate structure contains the active functional groups required for immobilizing the ligand. Currently, the carrier substrates for blood endotoxin adsorbent materials include: polymers such as cellulose, polyvinyl alcohol, agarose, chitosan, polyamide, polyethersulfone, polyvinylidene fluoride, polystyrene, etc., and the carrier forms have also expanded from polymer fibers to resin microspheres, filter membranes, hydrogels, etc.; however, these carrier substrates do not fully possess all the functions or properties of good specific adsorption, high adsorption capacity, good biocompatibility, high anti-coagulation, and low non-specific adsorption of proteins in blood, so the carrier substrates must be subjected to coating, deposition, cross-linking, or grafting modification treatment. (3) It has also been found that polymyxin B (PMB) has specific adsorption effects on endotoxin in blood. Other cationic antimicrobial peptides with similar functions and effects include nisin and melittin; there are also some polymers or small molecule compounds, such as polyethyleneimine, polylysine, lysine, histidine, hexamethylenediamine, etc. used as ligands, all of which have different degrees of specific affinity for blood endotoxin. In recent years, the scientific optimization of the carrier substrates for related blood endotoxin adsorbent materials, the simplification of the surface modification scheme and process, the high stabilization of ligand bonding, and the excellent comprehensive adsorption function are still the collaborative research hotspots in the fields of chemistry, materials science, biology, and medicine. Summary of the Invention

[0003] According to the performance requirements of the polystyrene-bonded and immobilized polymyxin B adsorbent material for the treatment of endotoxemia by hemoperfusion, the present invention provides a new method for grafting polymyxin on the surface of polystyrene. The polymer chemical principle is that under the action of sodium hydroxide, chloromethylated polystyrene undergoes a nucleophilic substitution reaction with diallylamine in a solvent to obtain diallylaminated polystyrene; then the diallylaminated polystyrene undergoes an amphoteric ionized reaction with an amphoteric ionizing reagent to obtain an unsaturated amphoteric ionized polystyrene with high hydrophilicity on the surface; thereafter, the unsaturated amphoteric ionized polystyrene, an amphoteric ion monomer containing a glycidyl group, and a gemini amphoteric ion crosslinker containing a glycidyl group are subjected to a graft copolymerization reaction to graft a polyamphoteric ion chain and a large number of glycidyl ether units on the side chain thereof on the surface of polystyrene to obtain a polyamphoteric ionized polystyrene containing glycidyl ether groups; and then through the ring-opening reaction of the glycidyl ether groups contained in the polyamphoteric ionized polystyrene with the amino groups of polymyxin, polymyxin is grafted on the surface of polystyrene to obtain polymyxinated polystyrene.

[0004] The innovative feature of the present invention is to use existing cheap industrial substances as raw materials and adopt classical chemical reactions to graft polymyxin on the surface of polystyrene, achieving a multi-functional effect: First, the polyamphoteric ion chain grafted on the surface of the polystyrene material makes the polystyrene exhibit high hydrophilicity, high water retention, excellent blood compatibility and tissue compatibility, an antifouling function of highly efficient anti-protein non-specific adhesion, and an anti-clotting function; Second, the density of polymyxin introduced by bonding on the surface of polystyrene can be adjusted, and the stability of the bonded and immobilized polymyxin is high, which has positive significance for improving the use of polymyxinated polystyrene as a hemoperfusion adsorbent material for the treatment of endotoxemia.

[0005] It is well-known to professionals that polystyrene is a thermoplastic synthetic polymer material with a wide range of uses, having good thermal processing properties, excellent mechanical properties, high chemical structural stability, and no biological toxicity. Although there are no active groups in the intrinsic structure of polystyrene for bonding and grafting polymyxin, through functionalization reactions such as nitration, sulfonation, chloromethylation, and chloroacetylation of polystyrene, various active groups can be obtained for bonding and grafting polymyxin. In particular, the industrialized macroporous hollow chloromethylated cross-linked polystyrene resin is a reactive polystyrene product with a wide source, low price, strong rigidity, and resistance to a variety of solvents, and has become the preferred substrate for a variety of functional polymer materials. The present invention selects the diallylamination scheme of macroporous hollow chloromethylated cross-linked polystyrene based on: ① diallylaminated cross-linked polystyrene can be conveniently converted into surface-unsaturated zwitterionic polystyrene; ② the surface-unsaturated zwitterionic polystyrene can carry out graft copolymerization reaction with a zwitterionic monomer carrying a glycidyl group; ③ the glycidyl groups remaining on the surface after the graft copolymerization of polystyrene can carry out ring-opening reaction with the amino group of polymyxin under mild conditions, which is the basis for the adjustable density of polystyrene grafted with polymyxin; ④ the whole process of polystyrene grafted with polymyxin in the present invention does not require drastic chemical processes such as oxidation and reduction, which is of great significance for ensuring the adsorption performance, biological activity, and medicinal value of the material after polystyrene is grafted with polymyxin.

[0006] It is well-known to professionals that zwitterionic polymers refer to polymers containing both positive and negative ionic groups in a structural unit of their polymer chains, and the polymer as a whole shows electrical neutrality. It has stronger electrostatic interaction with water molecules, thus having excellent hydrophilicity; the chemical structure of zwitterionic polymers is similar to that of biological membranes, making them have better biocompatibility and anti-protein non-specific adsorption performance. However, the existing publicly available high-molecular materials for bonding and immobilizing polymyxin as endotoxin adsorption materials for blood purification only focus on the endotoxin adsorption, biocompatibility, and anti-coagulation functions of the adsorption materials, and do not pay attention to the adhesion of some proteins in the blood to the adsorption materials, which is one of the key factors significantly affecting its endotoxin adsorption performance. The present invention precisely uses the polyzwitterionic chains bonded and connected on the surface of polystyrene to endow the surface of the polymyxinated polystyrene with better biocompatibility and anti-protein non-specific adsorption performance, which is of great significance for ensuring the endotoxin adsorption performance of the polymyxinated polystyrene material.

[0007] It is well-known to professionals that polymyxin is a general term for a group of basic polypeptide antibiotics. It was discovered in 1947 and produced by Bacillus polymyxa. Its chemical structure is a cyclic decapeptide sequence, including a heptapeptide ring connected to a tripeptide chain. Three side amino groups are connected to the heptapeptide ring, and two side amino groups are connected to the tripeptide chain (the five side amino groups are the functional groups for the bonding of polymyxin and high-molecular materials). In addition, the amino acid residue end at the tail of the tripeptide chain has a fatty acid tail chain. Different compositions of amino acids and fatty acids result in different chemical structures, mainly including 5 types: A, B, C, D, and E. Among them, polymyxin B has been used to treat various Gram-negative bacterial infections such as Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae, and Haemophilus influenzae, and belongs to the cationic antimicrobial peptides in antibiotics. Another characteristic is that it has a high specific affinity for lipopolysaccharide (i.e., endotoxin) released in large amounts after the death of Gram-negative bacteria, and it is the preferred ligand for removing endotoxin in the blood by adsorption. Currently, the fermentation production technology of polymyxin B has been industrialized, which provides the material conditions for the preferred ligand for the low-cost promotion of polymyxin for the treatment of endotoxemia.

[0008] The zwitterionic monomer containing glycidyl group described in the present invention has the structure shown in the general formula (I):

[0009]

[0010] Among them, R in the general formula (I) is selected from one of C 1 ~C 18 hydrocarbon groups, and the Q - refers to -CH 2 CH 2 CH 2 SO 3 - 、-CH 2 CH(OH)CH 2 SO 3 - 、-CH 2 CH 2 SO 3 - 、-CH 2 CH 2 CH 2 CH 2 SO 3 - 、-CH 2 CH 2 CH 2 CO 2 - 、-CH 2 CH 2 CO 2- 、 or -CH 2 CO 2 - among others.

[0011] The glycidyl - containing zwitterionic monomer described in general formula (I) can retain the glycidyl group after radical polymerization. The latter can undergo a ring - opening reaction with substances containing N - H groups in a neutral, weakly alkaline, or moderately strong alkaline aqueous solution system, thereby grafting a polymer or small - molecule compound with an amino group onto the surface of the polystyrene material in a bonding manner. The reaction conditions are mild, the process control is simple, and the reaction efficiency is high; especially for N - H - containing bioactive substances (such as polymyxin, nisin, melittin, human serum albumin, etc.) that have biological activity and are sensitive to media, temperature, or pH, it is more significant.

[0012] The glycidyl - containing zwitterionic monomer described in general formula (I) is also an amphiphilic compound, and the radical copolymerization reaction in aqueous solution on the surface of the highly hydrophilic unsaturated zwitterionic polystyrene has a high grafting efficiency; if, for example, by specifying the R hydrocarbon group in general formula (I), such as preferably allyl, benzyl, C 7 ~C 16 hydrocarbon group, while highlighting the hydrophilic characteristics of the glycidyl - containing zwitterionic monomer, it can also exhibit its high - efficiency biocidal and antibacterial efficacy; this is the scientific basis for the present invention to select the glycidyl - containing zwitterionic compound described in general formula (I) as the grafting monomer of the present invention.

[0013] The cross - linker used for grafting on the surface of the polystyrene material is a glycidyl - containing gemini zwitterionic cross - linker, having the structure shown in general formula (II):

[0014]

[0015] wherein in general formula (II), is selected from C 1 ~C 18 alkylene or among others, wherein n is a natural number between 0 and 200; Q - refers to -CH 2 CH 2 CH 2 SO 3 - 、 -CH 2 CH(OH)CH 2 SO 3 - 、 -CH 2 CH 2 SO 3 - 、 -CH 2CH 2 CH 2 CH 2 SO 3 - 、 - CH 2 CH 2 CH 2 CO 2 - 、 - CH 2 CH 2 CO 2 - 、 - CH 2 CO 2 - or - CH 2 PO 3 H - one of the following.

[0016] It is well known to professionals that in the surface graft polymerization process of polymer materials, there is an insurmountable defect, which is the homopolymerization problem of monomer raw materials. For example, the homopolymerization phenomenon of the glycidyl - containing zwitterionic monomer described by the general formula (I) not only causes ineffective consumption of raw materials, but also brings a necessary cleaning process to the re - functionalization process after surface grafting of polystyrene membrane materials. The glycidyl - containing gemini zwitterionic cross - linker described in the present invention is an unsaturated gemini betaine containing glycidyl groups, which is used as a cross - linker for graft copolymerization on the surface of polystyrene membrane materials. The purpose is to improve the grafting efficiency of the glycidyl - containing zwitterionic monomer described by the general formula (I) and ensure the utilization rate of monomer raw materials during the grafting process; and at the same time, it is expected that both ends of the polyzwitterionic chain after graft copolymerization are fixed on the polystyrene surface, presenting a flat - lying extended state, which is not only beneficial to the formation of a hydration layer by binding water molecules on the polystyrene surface, but also can avoid the curling and accumulation of the other end of the polyzwitterionic chain with a single - end fixation, blocking the ultrafiltration pores of polystyrene. It is of great significance for ensuring the adsorption rate and adsorption efficiency of polymyxin grafted on the polystyrene surface during the blood perfusion process.

[0017] The blocking agent refers to one of hydroxylamine hydrochloride, ethanolamine, tromethamine, or amino acid. Using the blocking agent to carry out graft capping after grafting polymyxin on the polystyrene surface aims to eliminate the residual glycidyl ether groups, because the latter has chemical reactivity with some proteins in the blood, affecting the protein recovery rate in blood perfusion.

[0018] Among them, the amino acid has the structure shown in the general formula (III):

[0019]

[0020] Among them, in the general formula (III), is selected from C 1 ~C 18Alkylene group, where W is selected from -SO 3 H, -COOH or -PO 3 H 2 One of the following.

[0021] The present invention uses amino acids as the blocking agent after grafting polymyxin on the surface of polystyrene. This is not only because the amino group with high chemical activity is contained in its molecular structure, but also because amino acids have diverse physical, chemical, biological and other characteristics and functions. As is well known to professionals, more than 20 natural amino acids are the raw materials for the composition of natural life forms known to ordinary people. However, the number and variety of functional groups carried in the molecular structures of these only natural amino acids are limited, including sulfhydryl, hydroxyl, guanidine, aromatic ring, heteroaromatic ring, carboxyl, amino, etc., which cannot meet the requirements for endowing materials with new functions in modern chemical and biological science research and applications. Currently, non-natural amino acids, also known as synthetic amino acids, artificially endowed with diverse functional groups through computer-aided design and chemical modification, have shown outstanding performance in the modification of synthetic materials and also provided more opportunities for biological research. In addition to the functional groups carried by natural amino acids in their molecular structures, these non-natural amino acids can also be functional groups such as keto group, aldehyde group, ester group, amide group, imide group, azide, alkyne group, alkene group, quaternary ammonium cation, nitro group, carboxylate group, phosphonate group, sulfonate group, polyether chain, etc., corresponding to different functional applications. The selection of the amino acid structure in the general formula (Ⅲ) of the present invention is based on the functional requirements of the polystyrene-based adsorbent material used for hemoperfusion. Not only can one of more than 20 natural amino acids be selected, but in non-protein amino acids or synthetic amino acids, amino acids with a combination of primary amino-carboxylic acid, primary amino-sulfonic acid, or primary amino-phosphonic acid can also be specifically optimized and selected, or preferably one of the amino acids with a combination of secondary amino-carboxylic acid, secondary amino-sulfonic acid, or secondary amino-phosphonic acid, so as to better improve or enhance the hydrophilicity, biocompatibility, anti-coagulation function and anti-fouling function of the polystyrene material, or endow the polystyrene grafted with polymyxin of the present invention with more powerful biomedical functions and wider applications.

[0022] The present invention provides a method for grafting polymyxin on the surface of polystyrene, which is achieved through the following steps:

[0023] Step 1: Preparation of surface diallylaminated polystyrene

[0024] Weigh chloromethylated polystyrene and put it into a solvent in a reactor. After swelling at room temperature for 2 to 24 hours, add diallylamine and a polymerization inhibitor, control the reaction temperature at 50 to 90 °C, and carry out the reaction for 20 to 24 hours. After completing the nucleophilic substitution reaction, cool to room temperature, filter out the polystyrene, and use a molar concentration of 0.2 to 2 mol·L -1The polystyrene is alkalized with an aqueous sodium hydroxide solution, and then washed with water until neutral. After drying, surface diallylaminated polystyrene is obtained. Reaction Scheme -1 schematically shows the process of preparing the surface diallylaminated polystyrene from chloromethylated polystyrene and diallylamine:

[0025]

[0026] Among them, chloromethylated polystyrene refers to one of chloromethylated crosslinked or non-crosslinked polystyrene macroporous hollow resin beads, chloromethylated crosslinked or non-crosslinked polystyrene macroporous hollow resin powder, chloromethylated crosslinked or non-crosslinked polystyrene microspheres, chloromethylated crosslinked or non-crosslinked polystyrene filter membranes, chloromethylated crosslinked or non-crosslinked polystyrene fibers, or chloromethylated crosslinked or non-crosslinked polystyrene open-cell foams; the chlorine mass percentage content in the chloromethylated polystyrene is 10-30%.

[0027] The solvent refers to one or more of methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, tert-butanol, tetrahydrofuran, 1,4-dioxane, 2-methoxyethanol, 2-ethoxyethanol, 2-methoxyethanol acetate, 2-ethoxyethanol acetate, ethyl acetate, methyl acetate, butyl acetate, toluene, acetone, butanone, anisole, chloroform, chlorobenzene, N-methylpyrrolidone, dimethyl sulfoxide, N,N-dimethylformamide or N,N-dimethylacetamide; the amount of the solvent used is 2-20 times the mass of the chloromethylated polystyrene.

[0028] The amount of the diallyl ammonium used is 1.0-2.5 times the molar amount of chlorine contained in the chloromethylated polystyrene.

[0029] The polymerization inhibitor is selected from one or more of hydroquinone, p-methoxyphenol, tert-butylhydroquinone, 2,6-dibutylhydroquinone, 2,6-di-tert-butyl-p-cresol, 2,4,6-tri-tert-butylphenol; the amount of the polymerization inhibitor used is 0.2-12% of the mass of the diallylamine.

[0030] The amount of the aqueous sodium hydroxide solution used is 0.5-5 times the mass of the chloromethylated polystyrene.

[0031] Step 2. Preparation of surface unsaturated zwitterionic polystyrene

[0032] Put the surface diallylaminated polystyrene prepared in Step 1 into a reactor with a solvent. After swelling at room temperature for 2 to 24 hours, add an amphoteric ionizing reagent and an inhibitor. Control the reaction temperature at 20 to 90 °C and carry out the reaction for 2 to 24 hours. After completing the amphoteric ionizing reaction, cool down to room temperature, filter out the polystyrene, wash the polystyrene with ethanol, and after centrifuging and drying, obtain surface unsaturated amphoteric ionized polystyrene; Reaction Formula - 2 schematically shows the process of preparing surface unsaturated amphoteric ionized polystyrene using the surface diallylaminated polystyrene and the amphoteric ionizing reagent as raw materials:

[0033]

[0034] The solvent mentioned above refers to one or more of methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, tert-butanol, tetrahydrofuran, 1,4-dioxane, 2-methoxyethanol, 2-ethoxyethanol, 2-methoxyethyl acetate, 2-ethoxyethyl acetate, ethyl acetate, methyl acetate, butyl acetate, toluene, acetone, butanone, anisole, chloroform, chlorobenzene, N-methylpyrrolidone, dimethyl sulfoxide, N,N-dimethylformamide or N,N-dimethylacetamide; the dosage of the solvent is 2 to 20 times the mass of the surface diallylaminated polystyrene.

[0035] The amphoteric ionizing reagent refers to one of 1,3-propanesultone, sodium 3-chloro-2-hydroxypropanesulfonate, sodium 2-bromoethylsulfonate, sodium 4-bromobutanesulfonate, γ-butyrolactone, β-propiolactone, sodium 2-chloroacetate or sodium 2-bromoethylphosphonate, and the dosage of the amphoteric ionizing reagent is 1.0 to 1.5 times the molar amount of N atoms contained in the surface diallylaminated polystyrene.

[0036] The inhibitor refers to one or more of hydroquinone, p-methoxyphenol, tert-butylhydroquinone, 2,6-dibutylhydroquinone, 2,6-di-tert-butyl-p-cresol, 2,4,6-tri-tert-butylphenol; the dosage of the inhibitor is 0.2 to 12% of the mass of the amphoteric ionizing reagent.

[0037] Step 3. Preparation of polyamphoteric ionized polystyrene containing glycidyl groups

[0038] The surface unsaturated zwitterionic polystyrene prepared in Step 2, the zwitterionic monomer containing glycidyl groups with the general formula (I), the gemini zwitterionic crosslinking agent containing glycidyl groups with the general formula (II), the aqueous initiator, and deionized water are mixed evenly together and then poured into a reaction kettle already filled with an organic solvent. After stirring and dispersing and purging with nitrogen to remove oxygen for 30 minutes, the temperature of the materials in the reaction kettle is controlled to 50-90 °C, and inverse suspension polymerization is carried out for 2-12 hours. Then, the polystyrene is filtered and recovered, and the filtered and recovered polystyrene is washed with water and centrifuged to be dried, thus obtaining polyzwitterionic polystyrene containing glycidyl groups; Reaction Formula-3 schematically shows the preparation process of polyzwitterionic polystyrene containing glycidyl groups:

[0039]

[0040] Among them, the zwitterionic monomer containing glycidyl groups has the structure shown in the general formula (I):

[0041]

[0042] Among them, R in the general formula (I) is selected from one of C 1 ~C 18 hydrocarbon groups, and the Q - refers to -CH 2 CH 2 CH 2 SO 3 - 、-CH 2 CH(OH)CH 2 SO 3 - 、-CH 2 CH 2 SO 3 - 、-CH 2 CH 2 CH 2 CH 2 SO 3 - 、-CH 2 CH 2 CH 2 CO 2 - 、-CH 2 CH 2 CO 2 - 、-CH 2 CO 2 - or -CH 2 PO 3 H - one of them.

[0043] The glycidyl-containing gemini zwitterionic crosslinking agent has the structure shown in general formula (II):

[0044]

[0045] Wherein in general formula (II), Select C 1 ~C 18 alkylene or one of them, wherein n is selected from natural numbers between 0 and 200; Q - refers to -CH 2 CH 2 CH 2 SO 3 - 、-CH 2 CH(OH)CH 2 SO 3 - 、-CH 2 CH 2 SO 3 - 、-CH 2 CH 2 CH 2 CH 2 SO 3 - 、-CH 2 CH 2 CH 2 CO 2 - 、-CH 2 CH 2 CO 2 - 、-CH 2 CO 2 - or -CH 2 PO 3 H - one of them.

[0046] The aqueous initiator refers to one or more of hydrogen peroxide, sodium persulfate, potassium persulfate, ammonium persulfate, 2,2'-azobis(2-methylpropionamidine) dihydrochloride, 2,2'-azobis(2-methyl-N-(2-hydroxyethyl)propionamide) dihydrochloride, 4,4'-azobis(4-cyanovaleric acid sodium salt), or 2,2'-azobis(2-isopropylimidazoline) dihydrochloride.

[0047] The organic solvent refers to one or more of chloroform, carbon tetrachloride, 1,2-dichloroethane, toluene, xylene, chlorobenzene, decalin, anisole, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, kerosene, diesel oil, paraffin oil, petroleum ether (boiling range 60-90 °C).

[0048] The mass ratio of the surface unsaturated quaternary ammonium cationized polystyrene / the zwitterionic monomer containing glycidyl group of general formula (I) / the gemini zwitterionic crosslinking agent containing glycidyl group of general formula (II) / the aqueous initiator / deionized water / organic solvent is 1: 0.1 - 3: 0.1 - 3: 0.03 - 0.13: 1 - 10: 2 - 200.

[0049] Step 4: Preparation of surface polymyxinated polystyrene

[0050] Under room temperature conditions, start stirring and add the polymyxin product to the buffer solution. After the polymyxin product is dissolved, add the polyzwitterionized polystyrene containing glycidyl group prepared in Step 3. Control the temperature between 20 - 40 °C and stir for 20 - 200 hours. Then add an aqueous solution of a blocking agent with a mass percentage concentration of 10 - 30%. Continue to stir and react at a constant temperature for 4 - 40 hours. Filter out the polystyrene, wash it with water until neutral, and centrifuge and dry it to obtain surface polymyxinated polystyrene. Reaction formula - 4 schematically shows the process of grafting polymyxin on the polystyrene surface:

[0051]

[0052] Among them, the mass ratio of the polyzwitterionized polystyrene containing glycidyl group / polymyxin product / buffer solution is 1 - 10: 0.1 - 5: 1 - 50.

[0053] The buffer solution refers to one of boric acid / borax buffer solution, boric acid / potassium chloride / sodium hydroxide buffer solution, sodium dihydrogen phosphate / sodium hydroxide buffer solution, borax / sodium hydroxide buffer solution, sodium bicarbonate / sodium carbonate buffer solution, or sodium carbonate / sodium hydroxide buffer solution with a pH value between 7.0 - 10.0;

[0054] The polymyxin product refers to one of polymyxin A, polymyxin B, polymyxin C, polymyxin D, polymyxin E, a mixture of polymyxin A + polymyxin B + polymyxin C + polymyxin D + polymyxin E in any mass ratio, polymyxin B sulfate, or colistimethate sodium.

[0055] The amount of the aqueous solution of the blocking agent is 0.3 - 3 times the mass of the polyzwitterionized polystyrene containing glycidyl group; among them, the blocking agent refers to one of ethanolamine, tromethamine, or amino acid.

[0056] Among them, the amino acid has the structure shown in general formula (III):

[0057]

[0058] Among them, in general formula (III) Selected from C 1 ~C 18 alkylene group, and the W is selected from -SO 3 H, -COOH or -PO 3 H 2 one of them.

[0059] The beneficial effects of the present invention are as follows:

[0060] ① By adopting the technical solution of the present invention, the crosslinking of the polyamphoteric cation graft chain is realized, and a woven structure is presented, which is closely attached to the surface of the polystyrene material in a flat-expanded state, and is covalently bonded to the surface of the polystyrene material through multiple-point covalent bonds of the woven structure. Therefore, the combination of the polyamphoteric cation graft chain and the surface of the polystyrene material is very firm. At the same time, by using the ring-opening reaction of the glycidyl ether unit on the outer layer of the polystyrene material surface, the stability of the grafted polymyxin is high, and the grafting density is adjustable, which is of great significance for ensuring the safety during medical treatment.

[0061] ② By adopting the technical solution of the present invention, the effect of the woven structure after crosslinking of the polyamphoteric cation graft chain coating the polystyrene material is realized. By combining water molecules, a highly covered hydration layer is formed on the surface of the polystyrene, which is not only beneficial for its rapid mixing with blood and easy contact adsorption of medium and small aqueous molecules in the blood on the polystyrene surface, but also has the function of preventing non-specific adsorption of proteins in the blood, which is beneficial for protein recovery during blood perfusion.

[0062] ③ By adopting the technical solution of the present invention, the multi-layer structure characteristics of the polystyrene material as the inner core layer + the woven structure of the polyamphoteric cation graft chain as the middle layer + the grafted polymyxin as the outermost layer are realized, which is of great significance for fully demonstrating the efficacy of the grafted polymyxin on the surface of the polystyrene material to adsorb endotoxin in the blood and quickly completing the equilibrium adsorption in a short time. Specific embodiments

[0063] The following examples are used to further illustrate a method for grafting polymyxin on the surface of polystyrene provided by the present invention, aiming to better understand the content of the present invention.

[0064] Example 1 Preparation of polymyxin B(1) grafted on the surface of polystyrene resin beads

[0065] Step 1: Weigh 20 g of chloromethylated crosslinked polystyrene hollow macroporous resin beads (manufactured by Nankai University Chemical Plant, commonly known as chlorinated beads, with a particle size of 0.45 - 0.65 mm, a crosslinking degree of 4.7%, and a Cl content of 17.34%) and mix them with 160 mL of N,N-dimethylformamide in a reaction kettle. Soak for 20 hours to fully swell. Then add 15.5 g of N,N-diallylamine and 0.85 g of hydroquinone to the reaction kettle. After purging with nitrogen to remove oxygen for 30 minutes, control the temperature of the materials in the reaction kettle to 40 - 50 °C, stir and react for 6 hours. Then raise the reaction temperature to 80 - 90 °C and stir and react for another 6 hours. Lower the temperature of the materials in the reaction kettle to room temperature, filter to recover the polystyrene resin beads, soak the recovered polystyrene resin beads in a caustic soda aqueous solution with a mass percentage concentration of 20%, and filter to recover the polystyrene resin beads. Then wash the polystyrene resin beads with water until neutral. Centrifuge and spin-dry at a constant speed of 2000 ± 200 revolutions per minute for 5 minutes to obtain 35.4 g of diallylaminated polystyrene resin beads. The water content of the diallylaminated polystyrene resin beads obtained by thermogravimetric analysis is 18.71%, and the chloromethyl conversion rate calculated by the weight gain method is 93.4%.

[0066] Step 2: Wash the 35.4 g of diallylaminated polystyrene resin beads obtained in Step 1 with ethanol 2 - 3 times, vacuum dry them, and then put them into 160 mL of N,N-dimethylformamide in a reaction kettle. Soak for 20 hours to fully swell. Add 13.6 g of 1,3-propanesultone and 0.85 g of 2,6-di-tert-butyl-p-cresol to the reaction kettle. After purging with nitrogen to remove oxygen for 30 minutes, control the temperature of the materials in the reaction kettle to 60 - 70 °C, stir and react for 16 hours. Lower the temperature of the materials in the reaction kettle to room temperature, filter to recover the polystyrene resin beads, wash the recovered polystyrene resin beads with ethanol, centrifuge and spin-dry at a constant speed of 2000 ± 200 revolutions per minute for 5 minutes to obtain 96.6 g of surface unsaturated zwitterionic polystyrene resin beads (1). The volatile content of the surface unsaturated zwitterionic polystyrene resin beads (1) obtained by thermogravimetric analysis is 50.56%, and the yield of the surface unsaturated zwitterionic polystyrene resin beads (1) calculated by the weight gain method is 98.2%.

[0067] Step 3: Weigh 30 g of deionized water, 10 g of 3-(N-glycidyl-N,N-diallylammonio)-1-propanesulfonate, 5 g of 1,4-bis(N-glycidyl-N-allyl-N-(3-sulfopropyl)ammonio)butane, 1.8 g of azobisisobutyramidine hydrochloride, and 96.6 g of the surface-unsaturated zwitterionic polystyrene resin beads prepared in Step 2. Mix them evenly and pour them into a polymerization reactor containing 250 mL of chlorobenzene. Purge with nitrogen to remove oxygen and stir for 0.5 h to disperse evenly. Control the temperature of the materials in the polymerization reactor to 50-60 °C, stir and polymerize for 4 h, then raise the temperature of the materials in the polymerization reactor to 80-85 °C, and stir and polymerize for another 6 h. Cool down, filter, and recover the polystyrene resin beads. Wash the polystyrene resin beads with ethanol and water respectively. After centrifuging and drying at a constant speed of 2000±200 revolutions per minute for 5 minutes, 127.2 g of polyzwitterionic polystyrene resin beads (1) containing glycidyl groups are obtained.

[0068] Using the GB1677-81 hydrochloric acid-acetone method, it is determined and calculated that the mass percentage content of epoxy groups in the polyzwitterionic polystyrene resin beads (1) containing glycidyl groups is 3.874% (the theoretical value is 4.216%). From this, the grafting rate is calculated to be 91.9%. According to thermogravimetric analysis, the moisture content is 60.13%. Using the mass increase method, the grafting rate of the polyzwitterionic polystyrene resin beads (1) containing glycidyl groups is calculated to be 92.6%. The calculation results of the two grafting rate detection methods are basically close, indicating that the preparation of the polyzwitterionic polystyrene resin beads (1) containing glycidyl groups is successful.

[0069] Step 4: Weigh 12 g of boric acid / borax buffer solution with a pH value of 7.5 into a reactor. Stir and add 3.2 g of polymyxin B sulfate at room temperature. After polymyxin B sulfate is dissolved, add 12.4 g of the polyquaternary ammonium cationic polystyrene resin beads (1) containing glycidyl groups prepared in Step 3. After stirring evenly, detect that the pH of the materials in the reactor is ≥7.0. Control the temperature of the materials in the reactor to 35-37 °C, stir and react for 24 h, filter out the polystyrene resin beads, and then put them into 12 g of ethanolamine aqueous solution with a mass concentration of 38%. Control the temperature at 35-37 °C and continue to stir and react for 4 h. Filter out the polystyrene resin beads again, wash them with deionized water until the washing water is neutral, and centrifuge and dry at a constant speed of 2000±200 revolutions per minute for 5 minutes to obtain polystyrene resin beads grafted with polymyxin B (1).

[0070] It is known from the sampled thermogravimetric analysis that the water content of the polymyxin B(1)-grafted polystyrene resin beads is 60.9%. The ninhydrin colorimetric method was used to measure the changes in the polymyxin B sulfate added to the boric acid / borax buffer solution before and after the reaction with the polyamphoteric ionized polystyrene resin beads(1) containing glycidyl groups. The grafting amount of polymyxin B(1) grafted on the surface of the polystyrene resin beads was calculated to be 263.5 mg / g, and the utilization rate of polymyxin B sulfate was also calculated to be 94.7%.

[0071] Example 2 Grafting of Polymyxin B(2) onto the Surface of Polystyrene Membrane Resin Beads

[0072] According to the preparation method and operation steps of Example 1:

[0073] Replace "13.6 g of 1,3-propanesultone" in Step 2 of Example 1 with "20.3 g of 3-chloro-2-hydroxypropanesulfonate sodium" to obtain surface unsaturated amphoteric ionized polystyrene resin beads(2). The volatile content of the surface unsaturated amphoteric ionized polystyrene resin beads(2) obtained by thermogravimetric analysis is 53.18%, and the yield of the surface unsaturated amphoteric ionized polystyrene resin beads(2) is calculated to be 76.3% by the weight gain method. It shows that when 1,3-propanesultone is replaced with 3-chloro-2-hydroxypropanesulfonate sodium, the utilization rate of 3-chloro-2-hydroxypropanesulfonate sodium may be low due to its low solubility in DMF.

[0074] Replace "10 g of 3-(N-glycidyl ether-N,N-diallylammonio)-1-propanesulfonate and 5 g of 1,4-bis(N-glycidyl-N-allyl-N-(3-sulfopropyl)ammonio)butane" in Step 3 of Example 1 with "0 g of 3-(N-glycidyl ether-N,N-diallylammonio)-1-propanesulfonate and 15 g of 1,4-bis(N-glycidyl-N-allyl-N-(3-sulfopropyl)ammonio)butane" to obtain polyquaternary ammonium cationized polystyrene resin beads(2) containing glycidyl groups. It is known from the thermogravimetric analysis that its moisture content is 57.72%, and the grafting rate of the polyamphoteric ionized polystyrene resin beads(2) containing glycidyl groups is calculated to be as high as 100% by the weight gain method. When all the amphoteric ion monomers are replaced with glycidyl ether-based gemini amphoteric ion crosslinking agents, the grafting rate of the polyamphoteric ionized polystyrene resin beads(2) containing glycidyl groups reaches 100%. It shows that the efficiency of the graft copolymerization reaction on the surface of the polymer material is determined by the crosslinking agent.

[0075] The remaining steps were carried out according to the method and procedures of Example 1 to obtain polymyxin B (2) grafted onto the surface of polystyrene resin beads. Through sampling and thermogravimetric analysis, it was found that the water content of polymyxin B (2) grafted onto the surface of polystyrene resin beads was 59.71%. Using the ninhydrin colorimetric method, the changes before and after the reaction of adding polymyxin B sulfate and polyamphoteric ionized polystyrene resin beads (2) containing glycidyl groups in the boric acid / borax buffer solution were measured. The grafting amount of polymyxin B (2) grafted onto the surface of polystyrene resin beads was calculated to be 220.1 mg / g, and at the same time, the utilization rate of polymyxin B sulfate was calculated to be 86.2%.

[0076] Example 3 Polymyxin B (3) grafted onto the surface of polystyrene film resin beads

[0077] According to the preparation method and operation steps of Example 1:

[0078] In step three of Example 1, "10 g of 3-(N-glycidyl-N,N-diallylammonio)-1-propanesulfonate and 5 g of 1,4-bis(N-glycidyl-N-allyl-N-(3-sulfopropyl)ammonio)butane" were replaced with "10 g of 3-(N-glycidyl-N-benzyl-N-allylammonio)-1-propanesulfonate and 5 g of 1,4-bis(N-glycidyl-N-allyl-N-(3-sulfopropyl)ammonio)butane" to obtain polyquaternary ammonium cationized polystyrene resin beads (3) containing glycidyl groups. Through thermogravimetric analysis, its moisture content was found to be 53.2%. The grafting rate of polyamphoteric ionized polystyrene resin beads (3) containing glycidyl groups was calculated to be 96.2% by the weight gain method.

[0079] The remaining steps were carried out according to the method and procedures of Example 1 to obtain polymyxin B (3) grafted onto the surface of polystyrene resin beads. Through sampling and thermogravimetric analysis, it was found that the water content of polymyxin B (3) grafted onto the surface of polystyrene resin beads was 59.32%. Using the ninhydrin colorimetric method, the changes before and after the reaction of adding polymyxin B sulfate and polyamphoteric ionized polystyrene resin beads (2) containing glycidyl groups in the boric acid / borax buffer solution were measured. The grafting amount of polymyxin B (2) grafted onto the surface of polystyrene resin beads was calculated to be 217.5 mg / g, and at the same time, the utilization rate of polymyxin B sulfate was calculated to be 87.1%.

[0080] Example 4 Polymyxin B (4) grafted onto the surface of polystyrene film resin beads

[0081] According to the preparation method and operation steps of Example 1:

[0082] Replace "13.6 g of 1,3 - propane sultone" in Step 2 of Example 1 with "18.5 g of γ - butyrolactone" to obtain surface - unsaturated zwitterionic polystyrene resin beads (3). The surface - unsaturated zwitterionic polystyrene resin beads (3) obtained by thermogravimetric analysis contain 55.43% volatile matter, and the yield of the surface - unsaturated zwitterionic polystyrene resin beads (3) calculated by the weight - gain method is 88.7%.

[0083] Replace "10 g of 3 - (N - glycidyl - N,N - diallylammonio) - 1 - propanesulfonate and 5 g of 1,4 - bis(N - glycidyl - N - allyl - N - (3 - sulfopropyl)ammonio)butane" in Step 3 of Example 1 with "10 g of 3 - (N - glycidyl - N,N - diallylammonio) - 1 - butyrate and 5 g of 1,4 - bis(N - glycidyl - N - allyl - N - (3 - carboxypropyl)ammonio)butane" to obtain polyquaternary ammonium cationic polystyrene resin beads (3) containing glycidyl groups. It is known from thermogravimetric analysis that its moisture content is 53.2%, and the grafting rate of the polyzwitterionic polystyrene resin beads (3) containing glycidyl groups calculated by the weight - gain method is 96.2%.

[0084] The remaining steps are carried out according to the method and steps of Example 1 to obtain polystyrene resin beads grafted with polymyxin B (4) on the surface. It is known from sampling thermogravimetric analysis that the water content of the polystyrene resin beads grafted with polymyxin B (4) on the surface is 55.33%. Using the ninhydrin colorimetric method, the changes before and after the reaction of adding polymyxin B sulfate and the polyzwitterionic polystyrene resin beads (3) containing glycidyl groups in the boric acid / borax buffer solution are measured. The grafting amount of the polystyrene resin beads grafted with polymyxin B (4) on the surface is calculated to be 301.3 mg / g, and at the same time, the utilization rate of polymyxin B sulfate is calculated to be 96.5%.

[0085] Example 5: Polystyrene film resin beads grafted with polymyxin B (5)

[0086] According to the preparation method and operation steps of Example 1:

[0087] Replace "13.6 g of 1,3 - propane sultone" in Step 2 of Example 1 with "18.5 g of γ - butyrolactone" to obtain surface - unsaturated zwitterionic polystyrene resin beads (3). The surface - unsaturated zwitterionic polystyrene resin beads (3) obtained by thermogravimetric analysis contain 45.43% volatile matter, and the yield of the surface - unsaturated zwitterionic polystyrene resin beads (3) calculated by the weight - gain method is 88.7%.

[0088] Replace "10 g of 3-(N-glycidyl-N,N-diallylammonio)-1-propanesulfonate and 5 g of 1,4-bis(N-glycidyl-N-allyl-N-(3-sulfopropyl)ammonio)butane" in Step 3 of Example 1 with "10 g of 3-(N-glycidyl-N,N-diallylammonio)-1-butyrate and 5 g of 1,4-bis(N-glycidyl-N-allyl-N-(3-carboxypropyl)ammonio)butane" to obtain the polyquaternary ammonium cationized polystyrene resin beads (3) containing glycidyl groups. It is known from thermogravimetric analysis that its moisture content is 61.32%, and the grafting rate of the polyzwitterionic polystyrene resin beads (3) containing glycidyl groups is calculated to be 96.2% by the weight gain method.

[0089] Replace "12 g of an aqueous ethanolamine solution with a mass percentage concentration of 38%" in Step 4 with "15 g of an aqueous glycine solution with a mass percentage concentration of 20% and a pH value of 11.0" to obtain the polystyrene resin beads grafted with polymyxin B (5) on the surface. It is known from sampling thermogravimetric analysis that the water content of the polystyrene resin beads grafted with polymyxin B (5) on the surface is 61.08%. Using the ninhydrin colorimetric method, the changes before and after the reaction of polymyxin B sulfate and the polyzwitterionic polystyrene resin beads (3) containing glycidyl groups added to the boric acid / borax buffer solution are measured, and the grafting amount of the polystyrene resin beads grafted with polymyxin B (5) on the surface is calculated to be 298.5 mg / g, and at the same time, the utilization rate of polymyxin B sulfate is calculated to be 92.3%.

[0090] Example 6 Polystyrene film resin beads grafted with polymyxin B (6)

[0091] According to the preparation method and operation steps of Example 1:

[0092] Replace "13.6 g of 1,3-propanesultone" in Step 2 of Example 1 with "18.5 g of γ-butyrolactone" to obtain the surface unsaturated zwitterionic polystyrene resin beads (3). The volatile content of the surface unsaturated zwitterionic polystyrene resin beads (3) obtained by thermogravimetric analysis is 45.43%, and the yield of the surface unsaturated zwitterionic polystyrene resin beads (3) is calculated to be 88.7% by the weight gain method.

[0093] Replace "10 g of 3-(N-glycidyl-N,N-diallylammonio)-1-propanesulfonate and 5 g of 1,4-bis(N-glycidyl-N-allyl-N-(3-sulfopropyl)ammonio)butane" in Step 3 of Example 1 with "13.5 g of 3-(N-glycidyl-N-dodecyl-N-allylammonio)-1-butyrate and 5 g of 1,4-bis(N-glycidyl-N-allyl-N-(3-carboxypropyl)ammonio)butane" to obtain the polyquaternary ammonium cationized polystyrene resin beads (4) containing glycidyl groups. It is known from thermogravimetric analysis that its moisture content is 61.10%, and the grafting rate of the polyzwitterionic polystyrene resin beads (4) containing glycidyl groups is calculated to be 95.6% by the weight gain method.

[0094] Replace "12 g of 38% ethanolamine aqueous solution" in Step 4 with "15 g of 20% glycine aqueous solution with a pH value of 11.0" to obtain the polystyrene resin beads grafted with polymyxin B (6) on the surface. It is known from sampling thermogravimetric analysis that the water content of the polystyrene film resin beads grafted with polymyxin B (6) on the surface is 60.37%. Using the ninhydrin colorimetric method, the changes before and after the reaction of polymyxin B sulfate and the polyzwitterionic polystyrene resin beads (4) containing glycidyl groups added to the boric acid / borax buffer solution are measured, and the grafting amount of the polystyrene film resin beads grafted with polymyxin B (6) is calculated to be 302.3 mg / g, and the utilization rate of polymyxin B sulfate is calculated to be 94.3% at the same time.

[0095] Example 7 Polystyrene film resin beads grafted with polymyxin B (7)

[0096] According to the preparation method and operation steps of Example 1:

[0097] Replace "13.6 g of 1,3-propanesultone" in Step 2 of Example 1 with "18.5 g of sodium chloroacetate" to obtain the surface unsaturated zwitterionic polystyrene resin beads (4). The volatile content of the surface unsaturated zwitterionic polystyrene resin beads (4) obtained by thermogravimetric analysis is 43.76%, and the yield of the surface unsaturated zwitterionic polystyrene resin beads (4) is calculated to be 80.6% by the weight gain method.

[0098] Replace "10 g of 3-(N-glycidyl-N,N-diallylammonio)-1-propanesulfonate and 5 g of 1,4-bis(N-glycidyl-N-allyl-N-(3-sulfopropyl)ammonio)butane" in Step 3 of Example 1 with "13.5 g of 3-(N-glycidyl-N-dodecyl-N-allylammonio)-1-butyrate and 5 g of 1,4-bis(N-glycidyl-N-allyl-N-(3-carboxypropyl)ammonio)butane" to obtain the polyquaternary ammonium cationized polystyrene resin beads (5) containing glycidyl groups. It is known from thermogravimetric analysis that its moisture content is 61.35%, and the grafting rate of the polyzwitterionic polystyrene resin beads (5) containing glycidyl groups is calculated to be 90.9% by the weight gain method.

[0099] Replace "12 g of an ethanolamine aqueous solution with a mass percentage concentration of 38%" in Step 4 with "20 g of a lysine aqueous solution with a mass percentage concentration of 20% and a pH value of 10.0" to obtain the polystyrene resin beads grafted with polymyxin B (7) on the surface. It is known from sampling thermogravimetric analysis that the water content of the polystyrene film resin beads grafted with polymyxin B (7) on the surface is 60.73%. The ninhydrin colorimetric method is used to measure the changes before and after the reaction of polymyxin B sulfate and the polyzwitterionic polystyrene resin beads (5) containing glycidyl groups added to the boric acid / borax buffer solution. The grafting amount of polymyxin B (7) grafted on the surface of the polystyrene film resin beads is calculated to be 296.4 mg / g, and at the same time, the utilization rate of polymyxin B sulfate is calculated to be 92.9%.

[0100] It can be seen from the examples of the present invention that the present invention maintains more than 3 times the theoretical dosage of polymyxin B and adopts a high-concentration polymyxin B reaction system in order to reduce the sharing of adjacent glycidyl groups on the surface of the polyzwitterionic polystyrene resin beads containing glycidyl groups by 5 amino groups of a single polymyxin molecule, which affects the grafting quantity and grafting efficiency of polymyxin B. The results show that the technical scheme of the present invention realizes the intention of efficiently grafting polymyxin B on the surface of the polystyrene film resin beads. In addition, from the results of grafting polymyxin B on the surface of the polystyrene film resin beads in Examples 1 to 7, the increase in the alkalinity of the aqueous solution of the blocking agent is not conducive to improving the grafting efficiency of polymyxin B grafted on the surface of the polystyrene film resin beads.

Claims

1. A method for grafting polymyxin onto the surface of polystyrene, characterized in that The following preparation steps are adopted: Step 1: Preparation of surface diallylamine-modified polystyrene Weigh chloromethylated polystyrene and put it into the solvent in the reactor. After swelling at room temperature for 2 to 24 hours, add diallylamine and polymerization inhibitor, control the reaction temperature to 50 to 90 ° C, and react for 20 to 24 hours. After the nucleophilic substitution reaction is completed, cool it to room temperature, filter out the polystyrene, and use a molar concentration of 0.2 to 2 mol·L -1 The polystyrene was treated with a caustic soda aqueous solution, and then washed with clean water until it was neutral, and dried to obtain the surface diallylamine polystyrene; Step 2: Preparation of surface unsaturated zwitterionic polystyrene The surface diallylamine polystyrene obtained in step 1 is put into a solvent in a reactor, and after swelling at room temperature for 2 to 24 hours, a zwitterionizing agent and a polymerization inhibitor are added, the reaction temperature is controlled at 20 to 90° C., and the reaction is carried out for 2 to 24 hours. After the zwitterionization reaction is completed, the temperature is lowered to room temperature, the polystyrene is filtered out, the polystyrene is washed with ethanol, and the polystyrene is centrifuged to obtain surface unsaturated zwitterionized polystyrene; Step 3: Preparation of polyzwitterionic polystyrene containing glycidyl groups The surface unsaturated zwitterionic polystyrene prepared in step 2, the zwitterionic monomer containing glycidyl group of general formula (I), the Gemini zwitterionic crosslinking agent containing glycidyl group of general formula (II), an aqueous initiator, and deionized water are uniformly mixed together, poured into a reaction kettle already filled with an organic solvent, stirred and dispersed, and nitrogen-filled and deoxygenated for 30 minutes, the temperature of the materials in the reaction kettle is controlled to 50-90° C., and reverse suspension polymerization is performed for 2-12 hours, and the polystyrene is filtered and recovered, and the filtered and recovered polystyrene is washed with water, and centrifuged and dried to obtain polyzwitterionic polystyrene containing glycidyl group; The mass ratio of the surface unsaturated quaternary ammonium cationized polystyrene / the glycidyl group-containing zwitterionic monomer of the general formula (I) / the glycidyl group-containing gemini zwitterionic crosslinking agent of the general formula (II) / aqueous initiator / deionized water / organic solvent is 1:0.1-3:0.1-3:0.03-0.13:1-10:2-200; The glycidyl-containing zwitterionic monomer has a structure shown in general formula (I): Wherein R in the general formula (I) is selected from C1 to C 18 One of the hydrocarbon groups, the Q - Refers to -CH2CH2CH2SO3 - 、-CH2CH(OH)CH2SO3 - 、-CH2CH2SO3 - 、-CH2CH2CH2CH2SO3 - 、-CH2CH2CH2CO2 - 、-CH2CH2CO2 - 、-CH2CO2 - or -CH2PO3H - One of; The glycidyl-containing Gemini zwitterionic crosslinking agent has a structure shown in the general formula (II): Among them, Select C1~C 18 Alkylene or One of the following, wherein n is selected from a natural number between 0 and 200; Q - Refers to -CH2CH2CH2SO3 - 、-CH2CH(OH)CH2SO3 - 、-CH2CH2SO3 - 、-CH2CH2CH2CH2SO3 - 、-CH2CH2CH2CO2 - 、-CH2CH2CO2 - 、-CH2CO2 - or -CH2PO3H - One of; Step 4: Grafting polymyxin on polystyrene surface Under room temperature, stirring is started and a polymyxin product is added to the buffer solution. After the polymyxin product is dissolved, the polyzwitterionic polystyrene containing glycidyl groups prepared in step 3 is added, the temperature is controlled between 20 and 40° C., and the reaction is stirred for 20 to 200 hours. The polystyrene is filtered out, and then the polystyrene is added to a blocking agent aqueous solution with a mass percentage concentration of 10 to 30%. The temperature is controlled between 20 and 40° C., and the reaction is continued with stirring for 4 to 40 hours. The polystyrene is filtered out, washed with water until neutral, and centrifuged to obtain polystyrene surface grafted polymyxin; The mass ratio of the polyzwitterionic polystyrene containing glycidyl groups / polymyxin product / buffer solution is 1-10:0.1-5:1-50.

2. A method for grafting polymyxin onto the surface of polystyrene according to claim 1, characterized in that The solvent refers to one or more of methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, tert-butanol, tetrahydrofuran, 1,4-dioxane, 2-methoxyethanol, 2-ethoxyethanol, 2-methoxyethanol acetate, 2-ethoxyethanol acetate, ethyl acetate, methyl acetate, butyl acetate, toluene, acetone, butanone, anisole, chloroform, chlorobenzene, N-methylpyrrolidone, dimethyl sulfoxide, N,N-dimethylformamide or N,N-dimethylacetamide.

3. A method for grafting polymyxin onto the surface of polystyrene according to claim 1, characterized in that The polymerization inhibitor refers to one or more of hydroquinone, p-methoxyphenol, tert-butylhydroquinone, 2,6-dibutylhydroquinone, 2,6-di-tert-butyl-p-cresol, and 2,4,6-tri-tert-butylphenol.

4. A method for grafting polymyxin onto the surface of polystyrene according to claim 1, characterized in that The aqueous initiator refers to one or more of hydrogen peroxide, sodium persulfate, potassium persulfate, ammonium persulfate, azobisisobutylamidine hydrochloride, azobisisobutylimidazoline hydrochloride, 4,4'-azobis(sodium cyanovalerate), or azobisisopropylimidazoline hydrochloride.

5. A method for grafting polymyxin onto the surface of polystyrene according to claim 1, characterized in that The organic solvent refers to one or more of chloroform, carbon tetrachloride, 1,2-dichloroethane, toluene, xylene, chlorobenzene, decahydronaphthalene, anisole, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, kerosene, diesel, paraffin oil, and petroleum ether.

6. A method for grafting polymyxin onto the surface of polystyrene according to claim 1, characterized in that The buffer solution refers to one of a boric acid / borax buffer solution, a boric acid / potassium chloride / sodium hydroxide buffer solution, a sodium dihydrogen phosphate / sodium hydroxide buffer solution, a borax / sodium hydroxide buffer solution, a sodium bicarbonate / sodium carbonate buffer solution, or a sodium carbonate / sodium hydroxide buffer solution with a pH value between 7.0 and 10.

0.

7. A method for grafting polymyxin onto the surface of polystyrene according to claim 1, characterized in that The amino acid has a structure shown in general formula (III): Wherein the general formula (III) Selected from C1~C 18 The W is selected from one of -SO3H, -COOH or -PO3H2.

8. A method for grafting polymyxin onto the surface of polystyrene according to claim 1, characterized in that: In step 1, the amount of diallylamine used is 1.0 to 2.5 times the molar amount of chlorine contained in the chloromethylated polystyrene, the amount of the solvent used is 2 to 20 times the mass of the chloromethylated polystyrene, the amount of the inhibitor used is 0.2 to 12% of the mass of diallylamine, and the amount of the caustic soda aqueous solution used is 0.5 to 5 times the mass of the chloromethylated polystyrene; The chloromethylated polystyrene refers to one of chloromethylated cross-linked or non-cross-linked polystyrene macroporous hollow resin spheres, chloromethylated cross-linked or non-cross-linked polystyrene macroporous hollow resin powders, chloromethylated cross-linked or non-cross-linked polystyrene microspheres, chloromethylated cross-linked or non-cross-linked polystyrene filter membranes, chloromethylated cross-linked or non-cross-linked polystyrene fibers, or chloromethylated cross-linked or non-cross-linked polystyrene open-cell foams; wherein the mass percentage of chlorine in the chloromethylated polystyrene is 10 to 30%.

9. A method for grafting polymyxin onto the surface of polystyrene according to claim 1, characterized in that: The amount of the zwitterionization agent in step 2 is 1.0 to 1.5 times the molar amount of N atoms contained in the surface diallylamine polystyrene, the amount of the solvent is 2 to 20 times the mass of the surface diallylamine polystyrene, and the amount of the inhibitor is 0.2 to 12% of the mass of the zwitterionization agent; The zwitterionizing agent is one of 1,3-propane sultone, sodium 3-chloro-2-hydroxypropane sulfonate, sodium 2-bromoethyl sulfonate, sodium 4-bromobutyl sulfonate, γ-butyrolactone, β-propiolactone, or sodium 2-chloroacetate.

10. A method for grafting polymyxin onto the surface of polystyrene according to claim 1, characterized in that: The polymyxin product in step 4 refers to one of polymyxin A, polymyxin B, polymyxin C, polymyxin D, polymyxin E, a mixture of polymyxin A + polymyxin B + polymyxin C + polymyxin D + polymyxin E mixed in any mass ratio, polymyxin B sulfate, or polymyxin E sodium methanesulfonate; The blocking agent is one of ethanolamine, tromethamine, or amino acid, and the amount of the blocking agent aqueous solution is 0.3 to 3 times the mass of the polyzwitterionic polystyrene containing glycidyl groups.

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