Preparation method of sulfated sodium alginate polymer material

Abstract

The invention discloses a preparation method of a sulfated sodium alginate polymer material. The preparation method comprises the following steps: step 1, preparing a sodium alginate solution; step 2, preparation of tributylamine sodium alginate; step 3, adding the tributylamine sodium alginate prepared in the step 2 into N, N-dimethylformamide, and stirring at room temperature to obtain a tributylamine sodium alginate solution; adding the purified sulfur trioxide / pyridine complex into a tributylamine sodium alginate solution; a sulfated sodium alginate solution is prepared through a sulfuration synthesis reaction, precipitation, filtration and dialysis; and freeze-drying the sulfated sodium alginate solution to obtain the sulfated sodium alginate polymer material. The preparation method of the sulfated sodium alginate polymer material disclosed by the invention has the advantages of mild conditions, high yield and the like. The prepared product has very good protein affinity performance, can be used as a carrier material of protein drugs, and has a wide clinical application prospect.

Description

Technical Field

[0001] The present invention relates to the technical field of biomaterials, and in particular to a method for preparing a sulfated sodium alginate polymer material. Background Art

[0002] Protein drugs can promote cell growth, tissue repair and wound healing at the trauma site by regulating inflammation, clearing traumatic debris, and promoting cell proliferation, migration and collagen synthesis. However, their bioavailability and stability in tissue fluid are poor, which affects their healing performance. Therefore, suitable materials with excellent biological properties are needed as protein drug carriers to improve their stability and utilization.

[0003] Alginic acid is a natural polysaccharide extracted from brown algae. Sodium alginate is a marine bioresource considered an ideal bioresource for humanity's future due to its abundant reserves, renewable nature, and lack of secondary pollution. The most notable physical property of alginic acid macromolecules is their ability to chelate multivalent cations. This cation chelation allows for the simple preparation of alginic acid derivatives with diverse structures and properties. Alginic acid and its derivatives possess excellent biological activity and are widely used in the preparation of biomedical materials such as wound dressings, drug carriers, tissue engineering scaffolds, and bone tissue repair. However, the low degree and strength of binding between protein drug macromolecules and pure alginate macromolecules limits their application as protein drug carriers. Therefore, modification of alginate macromolecules is necessary to incorporate protein-affinity monomers into their carbon chain structure to enhance their protein-entrapment properties. Existing research has found that sulfated polysaccharides possess excellent biological properties, including antiviral, anticoagulant, anti-inflammatory, and high protein affinity, making them promising biomedical materials for use as anti-AIDS drugs, anticoagulants, protein markers, and drug carriers. For example, invention patent CN 117756956 A discloses a sulfated Eucheuma polysaccharide or sulfated Sargassum fusiformis polysaccharide for repairing oxalic acid-induced cell damage, thereby reducing the risk of stone formation and preventing the occurrence of urinary stones. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a method for preparing an alginate macromolecular material with good protein affinity.

[0005] The present invention provides a method for preparing a sulfated sodium alginate polymer material, comprising the following steps: Step 1, weighing sodium alginate, adding it to ultrapure water, and stirring at room temperature to obtain a sodium alginate aqueous solution; Step 2, after the sodium alginate aqueous solution prepared in step 1 is allowed to stand for a period of time, tributylamine is added to adjust the pH value of the solution, the solution is stirred and allowed to stand for a period of time, vacuum filtered and freeze-dried to obtain tributylamine sodium alginate; Step 3: adding the tributylamine sodium alginate prepared in step 2 to N,N-dimethylformamide and stirring at room temperature to obtain a tributylamine sodium alginate solution; adding a purified sulfur trioxide / pyridine complex to the tributylamine sodium alginate solution; performing a sulfurization synthesis reaction, precipitation filtration, and dialysis to obtain a sulfated sodium alginate solution; and freeze-drying the sulfated sodium alginate solution to obtain a sulfated sodium alginate polymer material.

[0006] Furthermore, the mass fraction of the sodium alginate solution in step 1 is 0.3%, and the stirring time is 12 h.

[0007] Furthermore, the standing temperature of the sodium alginate solution in step 2 is 4°C.

[0008] Furthermore, the tributylamine in step 2 is added dropwise, and the pH value of the solution is adjusted to be in the range of 6.0-6.5.

[0009] Furthermore, in step 2, the stirring condition is a vacuum environment, the stirring time is 4 h, the standing temperature is 4 ° C, and the standing time is 12 h.

[0010] Furthermore, the mass fraction of the tributylamine sodium alginate solution in step 3 is 0.6%.

[0011] Furthermore, the molar mass ratio of the tributylamine sodium alginate solution to the purified sulfur trioxide / pyridine complex in step 3 includes any one of 1:2, 1:4, 1:8 and 1:12.

[0012] Furthermore, the sulfurization synthesis reaction in step 3 refers to the reaction being carried out in a dry argon environment, and the reaction time is 12 h.

[0013] Furthermore, the precipitation filtration in step 3 refers to pouring the solution after the sulfide synthesis reaction into acetone, and dropping 0.1 M sodium hydroxide-ethanol solution to adjust the pH value to 7.0-8.0.

[0014] Furthermore, the dialysate in the intermediate dialysis in step 3 is 1 M sodium chloride solution and ultrapure water, and the dialysis time is 3 days.

[0015] The present invention has the following beneficial effects: (1) The preparation method of the present invention uses sodium alginate as a raw material, which is a renewable and degradable natural compound with abundant sources and low production costs. The product, sulfated sodium alginate polymer material, is a macromolecular material and is biodegradable.

[0016] (2) The present invention introduces sulfate groups into the carbon chain of the polysaccharide structure through a chemical synthesis method, and realizes the protein affinity of sodium alginate through the chemical binding between the sulfate groups and protein drugs.

[0017] (3) The sulfated sodium alginate polymer material prepared by the preparation method of the present invention has good protein affinity and can be used as a carrier material for protein drugs.

[0018] (4) The method for preparing the sulfated sodium alginate polymer material disclosed in the present invention has the advantages of mild conditions and high yield. The prepared product has excellent protein affinity and can be used as a carrier material for protein drugs, with broad clinical application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic diagram of the chemical structure changes in the synthesis reaction of sulfated sodium alginate prepared by the present invention.

[0020] Figure 2 These are the Fourier infrared spectra corresponding to sodium alginate, sodium tributylamine alginate, and sodium sulfated alginate.

[0021] Figure 3 Schematic diagram of the degree of sulfur substitution of sulfated sodium alginate in Example 1, Example 2, Example 3 and Example 4.

[0022] Figure 4 Schematic diagram of the maximum response value change curve of sulfated sodium alginate, sodium alginate and heparin and lactoferrin 4 prepared in Example 4. DETAILED DESCRIPTION

[0023] The present invention will be described in further detail below with reference to the accompanying drawings and data. It should be understood that the embodiments are only for illustrating the present invention and are not intended to limit the scope of the invention in any way.

[0024] The room temperature in the examples is 25°C.

[0025] Example 1 (1) Preparation of sodium alginate solution: Weigh 3 g of sodium alginate and add it to 900 mL of ultrapure water to obtain a sodium alginate solution with a mass fraction of 0.3%. Magnetic stirring was performed at 400 r / min at room temperature for 12 h to prepare a sodium alginate aqueous solution. The prepared uniform sodium alginate aqueous solution was placed in an ice bath and cooled to 4°C. Dowex ion exchange resin washed with acetone and dried was added to the cooled sodium alginate aqueous solution, and impurity ions in the sodium alginate aqueous solution were removed by vacuum filtration.

[0026] (2) Preparation of tributylamine sodium alginate: Tributylamine was added dropwise to a pure sodium alginate aqueous solution at 4°C, and the pH value of the solution was measured while adding the solution until it reached a value between 6.0 and 6.5. The sodium alginate aqueous solution with tributylamine was magnetically stirred under vacuum. After 4 h, the tributylamine sodium alginate solution was sealed and allowed to stand at 4°C. After 12 h, the tributylamine sodium alginate solution was freeze-dried at -55°C to prepare tributylamine sodium alginate.

[0027] (3) Purification of sulfur trioxide / pyridine complex: 10 g of sulfur trioxide / pyridine complex was placed in a glass frit funnel, and 50 mL of ice ultrapure water was added to the funnel. After stirring, the mixture was vacuum filtered and washed with water. The pH value of the filtrate was tested with pH filter paper. The water washing was repeated until the pH value of the filtrate dropped to between 6.0 and 7.0. The washed complex was washed twice with ice ethanol to remove residual water. The complex was washed with 50 mL of anhydrous dichloromethane and dried using a high vacuum filtration device to obtain a purified sulfur trioxide / pyridine complex. The order of these steps is not limited in this embodiment.

[0028] (4) Preparation of sulfated sodium alginate: Accurately weigh 0.3 g of dried tributylamine sodium alginate and add it to 45 mL of anhydrous N,N-dimethylformamide to obtain a tributylamine sodium alginate solution with a mass fraction of 0.6%. After magnetic stirring for 12 h, add purified sulfur trioxide / pyridine complex with a molar mass twice that of tributylamine sodium alginate to carry out sulfurization synthesis reaction. Argon gas dried over blue silica gel is introduced into the reaction system to ensure complete drying of the reaction system. After 12 h of sulfurization reaction, the obtained opaque solution is poured into 200 mL of acetone for precipitation, and 0.1 M sodium hydroxide-ethanol solution is added dropwise to adjust the pH of the mixture to between 7.0 and 8.0. Among them, the chemical structure change diagram of the synthesis reaction of sodium sulfate sodium alginate is shown in the figure below. Figure 1 The precipitate was filtered and dried using a Büchner funnel. The resulting sulfated sodium alginate was dissolved in 20 mL of ultrapure water and magnetically stirred for 4 hours. The solution was then dialyzed against a 1 M sodium chloride solution and then ultrapure water for 3 days each. The dialyzed sulfated sodium alginate was freeze-dried at -55°C to produce a sulfated sodium alginate polymer material.

[0029] Example 2 (1) Preparation of sodium alginate solution: Weigh 3 g of sodium alginate and add it to 900 mL of ultrapure water to obtain a sodium alginate solution with a mass fraction of 0.3%. Magnetic stirring was performed at 400 r / min at room temperature for 12 h to prepare a sodium alginate aqueous solution. The prepared uniform sodium alginate aqueous solution was placed in an ice bath and cooled to 4°C. Dowex ion exchange resin washed with acetone and dried was added to the cooled sodium alginate aqueous solution, and impurity ions in the sodium alginate aqueous solution were removed by vacuum filtration.

[0030] (2) Preparation of tributylamine sodium alginate: Tributylamine was added dropwise to a pure sodium alginate aqueous solution at 4°C, and the pH value of the solution was measured while adding the solution until it reached a value between 6.0 and 6.5. The sodium alginate aqueous solution with tributylamine was magnetically stirred under vacuum. After 4 h, the tributylamine sodium alginate solution was sealed and allowed to stand at 4°C. After 12 h, the tributylamine sodium alginate solution was freeze-dried at -55°C to prepare tributylamine sodium alginate.

[0031] (3) Purification of sulfur trioxide / pyridine complex: 10 g of sulfur trioxide / pyridine complex was placed in a glass frit funnel, and 50 mL of ice ultrapure water was added to the funnel. After stirring, the mixture was vacuum filtered and washed with water. The pH value of the filtrate was tested with pH filter paper. The water washing was repeated until the pH value of the filtrate dropped to between 6.0 and 7.0. The washed complex was washed twice with ice ethanol to remove residual water. After washing with 50 mL of anhydrous dichloromethane, the complex was dried using a high vacuum filtration device to obtain a purified sulfur trioxide / pyridine complex. The order of these steps is not limited in this embodiment.

[0032] (4) Preparation of sulfated sodium alginate: Accurately weigh 0.3 g of dried tributylamine sodium alginate and add it to 45 mL of anhydrous N,N-dimethylformamide to obtain a tributylamine sodium alginate solution with a mass fraction of 0.6%. After magnetic stirring for 12 h, add purified sulfur trioxide / pyridine complex with a molar mass 4 times that of tributylamine sodium alginate to carry out sulfurization synthesis reaction. Argon gas dried over blue silica gel is passed into the reaction system to ensure complete drying of the reaction system. After 12 h of sulfurization reaction, the obtained opaque solution is poured into 200 mL of acetone for precipitation, and 0.1 M sodium hydroxide-ethanol solution is added dropwise to adjust the pH of the mixture to between 7.0 and 8.0. The precipitate is filtered and dried using a Buchner funnel. The obtained sulfated sodium alginate is dissolved in 20 mL of ultrapure water and magnetically stirred for 4 h. It is then dialyzed using 1 M sodium chloride solution and ultrapure water for 3 days. The dialyzed sulfated sodium alginate was freeze-dried at -55°C to obtain sulfated sodium alginate polymer material.

[0033] Example 3 (1) Preparation of sodium alginate solution: Weigh 3 g of sodium alginate and add it to 900 mL of ultrapure water to obtain a sodium alginate solution with a mass fraction of 0.3%. Magnetic stirring was performed at 400 r / min at room temperature for 12 h to prepare a sodium alginate aqueous solution. The prepared uniform sodium alginate aqueous solution was placed in an ice bath and cooled to 4°C. Dowex ion exchange resin washed with acetone and dried was added to the cooled sodium alginate aqueous solution, and impurity ions in the sodium alginate aqueous solution were removed by vacuum filtration.

[0034] (2) Preparation of tributylamine sodium alginate: Tributylamine was added dropwise to a pure sodium alginate aqueous solution at 4°C, and the pH value of the solution was measured while adding the solution until it reached a value between 6.0 and 6.5. The sodium alginate aqueous solution with tributylamine was magnetically stirred under vacuum. After 4 h, the tributylamine sodium alginate solution was sealed and allowed to stand at 4°C. After 12 h, the tributylamine sodium alginate solution was freeze-dried at -55°C to prepare tributylamine sodium alginate.

[0035] (3) Purification of sulfur trioxide / pyridine complex: 10 g of sulfur trioxide / pyridine complex was placed in a glass frit funnel, and 50 mL of ice ultrapure water was added to the funnel. After stirring, the mixture was vacuum filtered and washed with water. The pH value of the filtrate was tested with pH filter paper. The water washing was repeated until the pH value of the filtrate dropped to between 6.0 and 7.0. The washed complex was washed twice with ice ethanol to remove residual water. After washing with 50 mL of anhydrous dichloromethane, the complex was dried using a high vacuum filtration device to obtain a purified sulfur trioxide / pyridine complex. The order of these steps is not limited in this embodiment.

[0036] (4) Preparation of sulfated sodium alginate: Accurately weigh 0.3 g of dried tributylamine sodium alginate and add it to 45 mL of anhydrous N,N-dimethylformamide to obtain a tributylamine sodium alginate solution with a mass fraction of 0.6%. After magnetic stirring for 12 h, add purified sulfur trioxide / pyridine complex with a molar mass 8 times that of tributylamine sodium alginate to carry out sulfurization synthesis reaction. Argon gas dried over blue silica gel is passed into the reaction system to ensure complete drying of the reaction system. After 12 h of sulfurization reaction, the obtained opaque solution is poured into 200 mL of acetone for precipitation, and 0.1 M sodium hydroxide-ethanol solution is added dropwise to adjust the pH of the mixture to between 7.0 and 8.0. The precipitate is filtered and dried using a Buchner funnel. The obtained sulfated sodium alginate is dissolved in 20 mL of ultrapure water and magnetically stirred for 4 h. It is then dialyzed using 1 M sodium chloride solution and ultrapure water for 3 days. The dialyzed sulfated sodium alginate was freeze-dried at -55°C to obtain sulfated sodium alginate polymer material.

[0037] Example 4 (1) Preparation of sodium alginate solution: Weigh 3 g of sodium alginate and add it to 900 mL of ultrapure water to obtain a sodium alginate solution with a mass fraction of 0.3%. Magnetic stirring was performed at 400 r / min at room temperature for 12 h to prepare a sodium alginate aqueous solution. The prepared uniform sodium alginate aqueous solution was placed in an ice bath and cooled to 4°C. Dowex ion exchange resin washed with acetone and dried was added to the cooled sodium alginate aqueous solution, and impurity ions in the sodium alginate aqueous solution were removed by vacuum filtration.

[0038] (2) Preparation of tributylamine sodium alginate: Tributylamine was added dropwise to a pure sodium alginate aqueous solution at 4°C, and the pH value of the solution was measured while adding the solution until it reached a value between 6.0 and 6.5. The sodium alginate aqueous solution with tributylamine was magnetically stirred under vacuum. After 4 h, the tributylamine sodium alginate solution was sealed and allowed to stand at 4°C. After 12 h, the tributylamine sodium alginate solution was freeze-dried at -55°C to prepare tributylamine sodium alginate.

[0039] (3) Purification of sulfur trioxide / pyridine complex: 10 g of sulfur trioxide / pyridine complex was placed in a glass frit funnel, and 50 mL of ice ultrapure water was added to the funnel. After stirring, the mixture was vacuum filtered and washed with water. The pH value of the filtrate was tested with pH filter paper. The water washing was repeated until the pH value of the filtrate dropped to between 6.0 and 7.0. The washed complex was washed twice with ice ethanol to remove residual water. After washing with 50 mL of anhydrous dichloromethane, the complex was dried using a high vacuum filtration device to obtain a purified sulfur trioxide / pyridine complex. The order of these steps is not limited in this embodiment.

[0040] (4) Preparation of sulfated sodium alginate: Accurately weigh 0.3 g of dried tributylamine sodium alginate and add it to 45 mL of anhydrous N,N-dimethylformamide to obtain a tributylamine sodium alginate solution with a mass fraction of 0.6%. After magnetic stirring for 12 h, add purified sulfur trioxide / pyridine complex with a molar mass 12 times that of tributylamine sodium alginate to carry out sulfurization synthesis reaction. Argon gas dried over blue silica gel is passed into the reaction system to ensure complete drying of the reaction system. After 12 h of sulfurization reaction, the obtained opaque solution is poured into 200 mL of acetone for precipitation, and 0.1 M sodium hydroxide-ethanol solution is added dropwise to adjust the pH of the mixture to between 7.0 and 8.0. The precipitate is filtered and dried using a Buchner funnel. The obtained sulfated sodium alginate is dissolved in 20 mL of ultrapure water and magnetically stirred for 4 h. It is then dialyzed using 1 M sodium chloride solution and ultrapure water for 3 days. The dialyzed sulfated sodium alginate was freeze-dried at -55°C to obtain sulfated sodium alginate polymer material.

[0041] Performance Characterization of Sulfated Sodium Alginate 1. Functional group structure analysis of the prepared sulfated sodium alginate: The functional groups and their distribution in the prepared sulfated sodium alginate macromolecular chain were measured by Fourier transform infrared spectrometer scanning at a scanning wavelength of 500 cm -1 -4000 cm -1 .

[0042] The results are as follows Figure 2 As shown in the Fourier infrared spectrum of sodium alginate, 3330 cm -1 The absorption peak at 2960 cm -1 The absorption peak at 1610 cm is the stretching vibration of the C-H bond. -1 and 1410 cm -1 The absorption peaks at 1090 cm are the antisymmetric stretching vibration and symmetric stretching vibration of COO-. -1 and 1032 cm -1 The absorption peak of 2965 cm-1 indicates the presence of COC groups. Compared with the Fourier infrared spectrum of sodium alginate, the absorption peak of 2965 cm-1 of tributylamine sodium alginate is -1 、2960 cm -1 and 2874 cm -1 There is a small and weak absorption peak at 1610 cm, which is formed by the stretching vibration of CH3, CH2 and CH groups in the chemical structure of tributylamine grafted to the COO- group through ionic bonds. The addition of tributylamine groups affects the stretching vibration of the COO- group, making it -1 and 1410 cm -1 At the same time, the addition of tributylamine groups makes the C=O group at 1740 cm -1 The absorption peak at 3330 cm is slightly enhanced. In the Fourier infrared spectrum of sulfated alginic acid, the hydroxyl group -1 The absorption peak intensity at the position of tributylamine group increases significantly. + Substitution reforms the COONa group, making the COO- group at 1610 cm -1 and 1410 cm -1 The stretching vibration of sulfated sodium alginate is enhanced at 1230 cm -1 There is a strong and narrow absorption peak at , which is the characteristic absorption peak of the stretching vibration of the S=O group in sulfated sodium alginate.

[0043] 2. Analysis of sulfated substitution degree of sulfated sodium alginate: The calculation formula of sulfated substitution degree is: DS= × = × Where S% is the sulfur content in sulfated sodium alginate; C% is the carbon content in sulfated sodium alginate; M (S) is the relative molecular mass of sulfur; M (C) is the relative molecular mass of carbon; #C is the number of carbon atoms in each sulfated sodium alginate monomer.

[0044] The results are as follows Figure 3 As shown in the figure, the sulfur substitution curve of sulfated sodium alginate shows a clear increasing trend with increasing sulfur trioxide / pyridine complex molar ratio. When the sulfur trioxide / pyridine complex molar ratio increases from 2 to 8, the sulfur substitution of sulfated sodium alginate increases from 1.04 to 1.86. When the sulfur trioxide / pyridine complex molar ratio continues to increase to 12, the sulfur substitution of sulfated sodium alginate does not change significantly, but tends to be stable. Therefore, under the reaction conditions of 25°C and 12 hours, the maximum sulfur substitution of sulfated sodium alginate is approximately 2.0.

[0045] Analysis of protein affinity of sulfated sodium alginate prepared in Example 4: (1) The protein affinity of sulfated sodium alginate, i.e., its interaction with proteins, was detected using a high-throughput molecular interaction analysis platform. First, sodium alginate, sulfated sodium alginate, and heparin were immobilized on sensor chips to prepare different ligand sensor chips.

[0046] (2) Preparation of HBS-EP solution: Weigh 17.5320 g NaCl, 0.8767 g EDTA, 2.3831 g HEPES, and 50 mL Tween 20 and dissolve them in a 1 L volumetric flask filled with 900 mL ultrapure water. Stir magnetically until a transparent solution is formed. Use 0.5 M sodium hydroxide solution to adjust the pH of the solution to 8.9, and then adjust the volume to 1 L. Weigh 1 mg of lactoferrin 4 and dissolve it in HBS solution to prepare a solution with a concentration of 1 mg / mL. Then perform a gradient dilution to prepare lactoferrin 4 solutions with concentrations of 200, 150, 100, 50, 25, 12.5, and 6.25 nM. The affinity between different ligand sensor chips and lactoferrin 4 macromolecules was tested using a high-throughput molecular interaction analysis platform.

[0047] The results are as follows Figure 4As shown, the maximum response values ​​obtained for lactoferrin 4 binding to different ligands increased significantly with increasing lactoferrin 4 concentration. The maximum response value for the binding of sodium alginate macromolecule to lactoferrin 4 was the smallest, significantly lower than that for heparin, and the difference between the maximum response values ​​increased significantly with increasing lactoferrin 4 concentration. In contrast, the maximum response value for the binding of sulfated sodium alginate macromolecule to lactoferrin 4 was significantly higher than that for heparin, and the difference between the two values ​​did not change with increasing lactoferrin 4 concentration. This suggests that the protein-specific affinity of sodium alginate macromolecules is poor, and the addition of sulfate groups significantly improves the protein affinity of sodium alginate macromolecules and increases the stability of their protein binding. Compared to drug carriers prepared from sodium alginate, drug carriers prepared from sulfated sodium alginate can improve the entrapment efficiency of protein drugs and better control the release process of protein drugs, prolonging their release time and improving the utilization rate of protein drugs.

[0048] The above describes in detail the preferred embodiments of the present invention. It should be understood that those skilled in the art can make numerous modifications and variations based on the concepts of the present invention without inventive effort. Therefore, any technical solutions that can be derived by those skilled in the art through logical analysis, reasoning, or limited experimentation based on the concepts of the present invention and the prior art should be within the scope of protection defined by the claims.

Claims

1. A method for preparing a sulfated sodium alginate polymer material, characterized in that: The following steps are involved: Step 1, weighing sodium alginate, adding it to ultrapure water, and stirring at room temperature to obtain a sodium alginate aqueous solution; Step 2, after the sodium alginate aqueous solution prepared in step 1 is allowed to stand for a period of time, tributylamine is added to adjust the pH value of the solution, the solution is stirred and allowed to stand for a period of time, vacuum filtered and freeze-dried to obtain tributylamine sodium alginate; Step 3: adding the tributylamine sodium alginate prepared in step 2 to N,N-dimethylformamide and stirring at room temperature to obtain a tributylamine sodium alginate solution; adding a purified sulfur trioxide / pyridine complex to the tributylamine sodium alginate solution; performing a sulfurization synthesis reaction, precipitation filtration, and dialysis to obtain a sulfated sodium alginate solution; and freeze-drying the sulfated sodium alginate solution to obtain a sulfated sodium alginate polymer material.

2. The preparation method according to claim 1, characterized in that The mass fraction of the sodium alginate solution described in step 1 is 0.3%, and the stirring time is 12 h.

3. The preparation method according to claim 1, characterized in that The standing temperature of the sodium alginate solution in step 2 is 4°C.

4. The preparation method according to claim 1, characterized in that The tributylamine in step 2 is added dropwise, and the pH value of the solution is adjusted to be in the range of 6.0-6.

5.

5. The preparation method according to claim 1, characterized in that In step 2, the stirring condition is a vacuum environment, the stirring time is 4 h, the standing temperature is 4 ° C, and the standing time is 12 h.

6. The preparation method according to claim 1, characterized in that The mass fraction of the tributylamine sodium alginate solution in step 3 is 0.6%.

7. The preparation method according to claim 1, characterized in that The molar mass ratio of the tributylamine sodium alginate solution to the purified sulfur trioxide / pyridine complex in step 3 includes any one of 1:2, 1:4, 1:8 and 1:

12.

8. The preparation method according to claim 1, characterized in that The sulfurization synthesis reaction in step 3 is carried out in a dry argon environment for 12 h.

9. The preparation method according to claim 1, characterized in that The precipitation filtration in step 3 refers to pouring the solution after the sulfide synthesis reaction into acetone, and dropping 0.1 M sodium hydroxide-ethanol solution to adjust the pH value to 7.0-8.

0.

10. The preparation method according to claim 1, characterized in that The dialysate in the dialysis in step 3 is 1 M sodium chloride solution and ultrapure water, and the dialysis time is 3 days.

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