A multiphase covalently cross-linked biopolymer material and a preparation method and application thereof

Abstract

The application provides a multi-phase covalently cross-linked biopolymer material and a preparation method and application thereof, relates to the technical field of biopolymer materials, and the multi-phase covalently cross-linked biopolymer material with a double-network interpenetrating structure prepared by the application has the following advantages: a high-density covalent network provides anti-dissolution and mechanical support, a low-density ionic network guarantees the freedom of chain segment movement and the flexibility of the network, an asymmetric structure of "strong skeleton-weak filling" is formed, the material has shape stability and elastic recovery capacity, the mechanical strength is significantly improved, the material has good swelling performance, and the mechanical strength and the swelling performance are balanced. The raw materials of the application are all selected from natural biopolymers, have good biocompatibility, the reaction is carried out in an aqueous phase, no organic solvent is needed, the condition is mild, the biological activity of the natural polymer is reserved, the process is simple, green and environmentally friendly, and easy to scale up.

Description

Technical Field

[0001] This invention relates to the field of biopolymer materials technology, and in particular to a multiphase covalently cross-linked biopolymer material, its preparation method, and its application. Background Technology

[0002] Hydrogels prepared from natural biopolymers such as chitosan, sodium alginate, and gelatin possess excellent biocompatibility, biodegradability, and hydrophilicity, and are widely used in pharmaceutical fields such as drug sustained-release carriers and hemostatic materials. However, single-network hydrogels face a fundamental contradiction between mechanical strength and swelling performance. Increasing the crosslinking density enhances strength but significantly reduces the swelling rate, making the material harder and more brittle; decreasing the crosslinking density maintains good swelling but results in poor mechanical properties and easy dissolution in physiological environments.

[0003] In the prior art, patent 202211244147.6 discloses a multiphase covalently cross-linked biopolymer material and its preparation method, which involves dissolving various natural biopolymers and reactive additives together, and then covalently cross-linking them in an all-aqueous solvent to obtain a biomembrane or a bioporous sponge. Patent 202010024053.2 discloses a novel 3D structured biopolymer material prepared by covalent reaction and its synthesis method, which uses chitin / chitosan polymers and a cross-linking agent containing multi-arm structure reactive additives to prepare biomembranes, gels, or sponges. A common feature of these methods is "one-step" cross-linking, where all raw materials are first dissolved and mixed into a homogeneous solution, and then a cross-linking agent is added to allow all components to react simultaneously, resulting in a single-phase homogeneous structure with a relatively uniform cross-linking density across all regions. However, none of the above techniques can simultaneously achieve both mechanical strength and swelling performance.

[0004] Therefore, the urgent need to construct a natural biopolymer hydrogel material with both high mechanical strength and good swelling properties is a key technical problem that has not yet been solved in this field. Summary of the Invention

[0005] In view of this, the present invention proposes a multiphase covalently cross-linked biopolymer material, its preparation method, and its application, thereby solving the above-mentioned problems. The technical solution of the present invention is implemented as follows: A method for preparing multiphase covalently cross-linked biopolymer materials, the specific preparation steps of which include: S1. Add the first natural biopolymer to water to obtain the first natural biopolymer solution, add a cross-linking agent and mix, pour the mixed solution into a mold for cross-linking to form the first network hydrogel; S2. Add the second natural biopolymer to water to obtain a second natural biopolymer solution. Add the first network hydrogel for permeation. Immerse the system in a multivalent metal ion solution for crosslinking to obtain a double network hydrogel. Freeze, heat and dry to obtain a multiphase covalently crosslinked biopolymer material with a double network interpenetrating structure.

[0006] Furthermore, in step S1, the crosslinking agent is any one of epichlorohydrin, tetra-arm polyethylene glycol glycidyl ether, pentaerythritol tetraglycidyl ether, octa-arm polyethylene glycol glycidyl ether, 1,4-butanediol diglycidyl ether, or glycerol triglycidyl ether.

[0007] Furthermore, in step S1, the first natural biopolymer is any one of water-soluble chitosan, carboxymethyl chitosan, or gelatin.

[0008] Furthermore, in step S1, the mass of the crosslinking agent is 5%-10% of the mass of the first natural biological macromolecule.

[0009] Furthermore, in step S1, the concentration of the first natural biopolymer solution is 1wt%-5wt%; the crosslinking is carried out at 30-60℃ and pH 7-8 for 24-48 hours.

[0010] Furthermore, in step S2, the second natural biopolymer is any one of sodium alginate, carboxymethyl cellulose, carrageenan, or pectin.

[0011] Furthermore, in step S2, the multivalent metal ion is Ca. 2+ Fe 3+ Zn 2+ or Cu 2+ Any one of them.

[0012] Furthermore, in step S2, the concentration of the second natural biological polymer solution is 0.5wt%-5wt%; the permeation is carried out at 20-40℃ for 6-8 hours; the concentration of the polyvalent metal ion solution is 0.1-1mol / L; the crosslinking is carried out at 30-40℃ for 10-12 hours; the freezing is carried out at a temperature of -18℃ to -25℃ for 6-12 hours; and the heating and drying is carried out at a temperature of 35-45℃ for 48-72 hours.

[0013] A multiphase covalently cross-linked biopolymer material is prepared by any of the preparation methods described above.

[0014] Application of a multiphase covalently cross-linked biopolymer material in the preparation of drug sustained-release carriers or hemostatic materials.

[0015] Compared with the prior art, the beneficial effects of the present invention are: 1. The multiphase covalently cross-linked biopolymer material with a dual-network interpenetrating structure prepared by this invention has a first network that is a permanent covalently cross-linked network and a second network that is a dynamic ionic cross-linked network. The cross-linking densities of the two networks differ by about one order of magnitude. The high-density covalent network provides resistance to dissolution and mechanical support, while the low-density ionic network ensures the freedom of chain segment movement and network flexibility, forming an asymmetric structure of "strong skeleton-weak filler". This endows the material with shape stability and elastic recovery ability, significantly improves mechanical strength, and has good swelling properties, thus balancing mechanical strength and swelling performance.

[0016] 2. The raw materials of the multiphase covalent crosslinked biopolymer material of the present invention are all natural biopolymers with good biocompatibility. The reactions are all carried out in the aqueous phase without the need for organic solvents. The conditions are mild, and the biological activity of natural polymers is preserved. The process is simple, green and environmentally friendly, and easy to scale up. Detailed Implementation

[0017] To better understand the technical content of this invention, specific embodiments are provided below to further illustrate the invention.

[0018] Unless otherwise specified, the experimental methods used in the embodiments of this invention are all conventional methods.

[0019] Unless otherwise specified, all materials and reagents used in the embodiments of this invention are commercially available.

[0020] The crosslinking agent of this invention is any one of epichlorohydrin, four-arm polyethylene glycol glycidyl ether, pentaerythritol tetraglycidyl ether, eight-arm polyethylene glycol glycidyl ether, 1,4-butanediol diglycidyl ether, or glycerol triglycidyl ether. The example uses four-arm polyethylene glycol glycidyl ether.

[0021] Example 1 A method for preparing multiphase covalently cross-linked biopolymer materials, the specific preparation steps of which include: S1. Add water-soluble chitosan to water to obtain a chitosan solution with a concentration of 3wt%. Add a crosslinking agent and mix. The mass of the crosslinking agent is 8% of the mass of the water-soluble chitosan. Pour the mixed solution into a mold and crosslink at 45℃ and pH 7.5±0.2 for 36 hours to form the first network hydrogel. S2. Sodium alginate was added to water to obtain a 1 wt% sodium alginate solution. The first network hydrogel was then added and allowed to permeate at 30°C for 7 hours. The volume ratio of the sodium alginate solution to the first network hydrogel was 1:10. The system was then immersed in 0.5 mol / L Ca2+ solution. 2+ In an ionic solution, crosslinking was performed at 35°C for 11 h to obtain a double-network hydrogel. The hydrogel was then frozen at -20°C for 8 h and then heated to 40°C for 60 h to obtain a multiphase covalently crosslinked biopolymer material with a double-network interpenetrating structure.

[0022] Example 2 A method for preparing multiphase covalently cross-linked biopolymer materials, the specific preparation steps of which include: S1. Add carboxymethyl chitosan to water to obtain a 1wt% carboxymethyl chitosan solution. Add a crosslinking agent and mix. The mass of the crosslinking agent is 5% of the mass of carboxymethyl chitosan. Pour the mixed solution into a mold and crosslink at 30℃ and pH 7.5±0.2 for 24 hours to form the first network hydrogel. S2. Carboxymethyl cellulose was added to water to obtain a 2 wt% carboxymethyl cellulose solution. The first network hydrogel was then added and allowed to permeate at 20°C for 6 hours. The volume ratio of the carboxymethyl cellulose solution to the first network hydrogel was 1:10. The system was then immersed in 0.1 mol / L Ca2+. 2+ In an ionic solution, crosslinking was performed at 30°C for 10 h to obtain a double-network hydrogel. The hydrogel was then frozen at -18°C for 6 h and then heated to 35°C for 48 h to obtain a multiphase covalently crosslinked biopolymer material with a double-network interpenetrating structure.

[0023] Example 3 A method for preparing multiphase covalently cross-linked biopolymer materials, the specific preparation steps of which include: S1. Add carboxymethyl chitosan to water to obtain a 5wt% carboxymethyl chitosan solution. Add a crosslinking agent and mix. The mass of the crosslinking agent is 10% of the mass of carboxymethyl chitosan. Pour the mixed solution into a mold and crosslink at 60℃ and pH 7.5±0.2 for 48 hours to form the first network hydrogel. S2. Sodium alginate was added to water to obtain a 3wt% sodium alginate solution. The first network hydrogel was then added and allowed to permeate at 40℃ for 8 hours. The volume ratio of the sodium alginate solution to the first network hydrogel was 1:10. The system was then immersed in 1mol / L Ca... 2+ In an ionic solution, crosslinking was performed at 40°C for 12 h to obtain a double-network hydrogel. The hydrogel was then frozen at -25°C for 12 h and then heated to 45°C for 72 h to obtain a multiphase covalently crosslinked biopolymer material with a double-network interpenetrating structure.

[0024] Comparative Example 1 This comparative example describes a method for preparing a multiphase covalently cross-linked biopolymer material, the specific preparation steps of which include: Water-soluble chitosan was added to water to obtain a 3wt% chitosan solution. A crosslinking agent was added and mixed, with the mass of the crosslinking agent being 8% of the mass of the water-soluble chitosan. The mixed solution was poured into a mold and crosslinked at 45℃ and pH 7.5±0.2 for 36 hours. It was then frozen at -20℃ for 8 hours and dried at 40℃ for 60 hours to obtain a multiphase covalently crosslinked biopolymer material.

[0025] Comparative Example 2 This comparative example describes a method for preparing a multiphase covalently cross-linked biopolymer material, the specific preparation steps of which include: Sodium alginate was added to water to obtain a 1 wt% sodium alginate solution and 0.5 mol / L Ca2+. 2+ Ionic solutions were mixed, crosslinked at 35°C for 11 hours, frozen at -20°C for 8 hours, and then dried at 40°C for 60 hours to obtain multiphase covalently crosslinked biopolymer materials.

[0026] Test Example 1 The mechanical properties and swelling properties of the multiphase covalently cross-linked biopolymers prepared according to the processes of Examples 1-3 and Comparative Examples 1-2 were tested.

[0027] The swelling performance test method is as follows: Weigh 0.1g of the multiphase covalently cross-linked biopolymer material (m0) prepared in Examples 1-3 and Comparative Examples 1-2 respectively, place it in a beaker, add 30mL of purified water and let it stand. After every 30 minutes, pour off the excess purified water, wipe off the surface moisture with moist filter paper and weigh it until the difference between two adjacent weighings is <1%, which means that swelling equilibrium has been reached. Record the equilibrium wet weight (m1). Each group has 3 parallels and the average value is taken.

[0028] Equilibrium swelling ratio = (m1-m0) / m0×100%.

[0029] The results are shown in Table 1.

[0030] Table 1

[0031] As can be seen from Table 1, the multiphase covalently cross-linked biopolymer materials of Examples 1-3 of the present invention take into account both mechanical properties and swelling properties.

[0032] Test Example 2 Multiphase covalently cross-linked biopolymers prepared in Examples 1-3 and Comparative Examples 1-2 were used as test samples for detection, and cytotoxicity and hemostasis time were detected respectively.

[0033] Cytotoxicity was determined according to GB / T 16886.5-2017 for cell viability, and hemostasis time was determined according to YY / T1477.5-2020. The results were stored in integer form.

[0034] The results are shown in Table 2.

[0035] Table 2

[0036] As can be seen from Table 2, the multiphase covalently cross-linked biopolymers prepared in Examples 1-3 have good hemostatic function and can be used to prepare hemostatic materials.

[0037] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing a multiphase covalently cross-linked biopolymer material, characterized in that, The specific preparation steps include: S1. Add the first natural biopolymer to water to obtain the first natural biopolymer solution, add a cross-linking agent and mix, pour the mixed solution into a mold for cross-linking to form the first network hydrogel; S2. Add the second natural biopolymer to water to obtain a second natural biopolymer solution. Add the first network hydrogel for permeation. Immerse the system in a multivalent metal ion solution for crosslinking to obtain a double network hydrogel. Freeze, heat and dry to obtain a multiphase covalently crosslinked biopolymer material with a double network interpenetrating structure.

2. The method for preparing a multiphase covalently cross-linked biopolymer material as described in claim 1, characterized in that, In step S1, the crosslinking agent is any one of epichlorohydrin, tetra-arm polyethylene glycol glycidyl ether, pentaerythritol tetraglycidyl ether, octa-arm polyethylene glycol glycidyl ether, 1,4-butanediol diglycidyl ether, or glycerol triglycidyl ether.

3. The method for preparing a multiphase covalently cross-linked biopolymer material as described in claim 1, characterized in that, In step S1, the first natural biopolymer is any one of water-soluble chitosan, carboxymethyl chitosan, or gelatin.

4. The method for preparing a multiphase covalently cross-linked biopolymer material as described in claim 1, characterized in that, In step S1, the mass of the crosslinking agent is 5%-10% of the mass of the first natural biological macromolecule.

5. The method for preparing a multiphase covalently cross-linked biopolymer material as described in claim 1, characterized in that, In step S1, the concentration of the first natural biopolymer solution is 1wt%-5wt%; the crosslinking is carried out at 30-60℃ and pH 7-8 for 24-48 hours.

6. The method for preparing a multiphase covalently cross-linked biopolymer material as described in claim 1, characterized in that, In step S2, the second natural biopolymer is any one of sodium alginate, carboxymethyl cellulose, carrageenan, or pectin.

7. The method for preparing a multiphase covalently cross-linked biopolymer material as described in claim 1, characterized in that, In step S2, the multivalent metal ion is Ca. 2+ Fe 3+ Zn 2+ or Cu 2+ Any one of them.

8. The method for preparing a multiphase covalently cross-linked biopolymer material as described in claim 1, characterized in that, In step S2, the concentration of the second natural biopolymer solution is 0.5wt%-5wt%; the permeation is carried out at 20-40℃ for 6-8 hours; the concentration of the polyvalent metal ion solution is 0.1-1mol / L; the crosslinking is carried out at 30-40℃ for 10-12 hours; the freezing is carried out at a temperature of -18℃ to -25℃ for 6-12 hours; and the heating and drying is carried out at a temperature of 35-45℃ for 48-72 hours.

9. A multiphase covalently cross-linked biopolymer material, characterized in that, It is prepared by the preparation method according to any one of claims 1-8.

10. The application of the multiphase covalently cross-linked biopolymer material according to claim 9 in the preparation of drug sustained-release carriers or hemostatic materials.

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