High-strength gelatin-curdlan hydrogel and preparation method thereof

Abstract

The invention belongs to the field of hydrogel material preparation, and particularly relates to high-strength gelatin-curdlan hydrogel and a preparation method thereof. The preparation method of the high-strength gelatin-curdlan hydrogel comprises the following steps: preparing a gelatin aqueous solution and a curdlan dimethyl sulfoxide solution, heating, uniformly mixing and slowly cooling the two solutions to obtain organic gel, removing an organic solvent from the organic gel, drying, and swelling the dry gel in water by absorbing water to obtain the high-strength composite hydrogel. Two natural polymers are used as raw materials, curdlan is driven to form a nanofiber structure in gelatin through high-temperature rapid mixed annealing and solvent conversion, the hydrogel with the interpenetrating network structure of nanofibers is formed, and the composite hydrogel has higher strength and higher biocompatibility compared with pure gelatin hydrogel and can be used for preparing the hydrogel with the interpenetrating network structure. The obvious application prospect is realized in the field of biomedical materials.

Description

Technical Field

[0001] The present invention belongs to the field of preparation of hydrogel materials, and particularly relates to a high-strength gelatin-curdlan hydrogel and a preparation method thereof. Background Art

[0002] Hydrogels are a class of polymer materials with liquid as the dispersion medium, which can swell in water and maintain the stability of their three-dimensional network structure. Due to the unique structure, water absorption, hydrophilicity, biocompatibility and easy modification of hydrogels, they have a wide range of applications in the fields of medicine, food, cosmetics, etc.

[0003] Gelatin is a natural polymer protein extracted from animal skins, cartilages and other tissues. It is a hydrolysis product of collagen, with good biocompatibility, low antigenicity and biodegradability. In addition, gelatin has the characteristics of dissolving at high temperature and gelling at low temperature, and can be used to prepare hydrogel materials, showing good application prospects in the biomedical field. However, the strength of traditional gelatin-based hydrogels is low, and further treatment is required to improve their mechanical properties.

[0004] At present, many researchers have proposed various strategies to improve the mechanical properties of gelatin materials. First of all, the most commonly used strategy is chemical cross-linking. For example, the patent document CN114672173A discloses a preparation method of glutaraldehyde-crosslinked gelatin sponge. Although chemical cross-linking can significantly improve the strength of gelatin, glutaraldehyde will be released during the degradation of gelatin, causing significant cytotoxicity, which is not conducive to applications in the biomedical field. In addition, the composite of gelatin with a synthetic polymer network can well improve the mechanical properties of gelatin-based hydrogels. For example, the patent document CN112038110A discloses a thermoreversible hydrogel electrolyte with ultra-high strength and its preparation method, in which polyvinyl alcohol and gelatin are compounded to prepare a high-strength hydrogel. However, adding chemically synthesized polymer materials will cause a certain degree of damage to the biological activity of the gelatin hydrogel itself, and there are problems such as difficult degradation. In addition, there are also reports suggesting that preparing a composite hydrogel of gelatin and inorganic nanoparticles can significantly improve the mechanical properties of gelatin-based hydrogels (such as the literature Nano Letters, 2019, 19(8): 5717-5724 and the literature Acta Biomaterialia, 2022, 149: 126-138.), however, the dispersibility of nano-material molecules in the gelatin matrix is poor, and it is difficult to prepare a hydrogel with uniform material. In order to avoid the use of toxic cross-linking agents or synthetic polymers, some studies have proposed to prepare high-strength gelatin hydrogels by the salt solution immersion method (refer to the patent document: CN110078945A One-step method for preparing high-strength gelatin hydrogels and their methods and the literature Advanced Functional Materials, 2018, 28(5): 1705069.), although this method is simple, the gelatin hydrogel needs to be under a high salt ion concentration to maintain high strength, and the strength drops rapidly after desalination, making it difficult to be applied to biomedical materials. Therefore, finding molecules of biological origin with good mechanical properties to be compounded with gelatin is beneficial to maintaining the biocompatibility of gelatin while improving its mechanical properties, and has better application prospects.

[0005] Curdlan is produced by a bacterium named Alcaligenes facealis var. myxogenes (10C3) isolated from soil by Professor Harada and others at Osaka University in Japan in 1964. It can form a colloid with good elasticity under heating conditions and is widely used in the field of food additives. In recent years, curdlan has been industrially produced in China. In addition, the curdlan molecule has a triple helix conformation similar to that of gelatin, with a larger molecular weight and higher strength than gelatin, and has the potential to be developed into a tissue substitute material. However, its structure lacks protein components, which is not conducive to binding with human tissues. If curdlan and gelatin are compounded to form a hydrogel, it is expected to obtain a biomedical material with excellent biocompatibility and mechanical properties. However, gelatin has good solubility in water, while curdlan has poor solubility in water. The contradiction in solubility makes it difficult for these two macromolecules to form a uniform hydrogel in water, and there are obvious technical difficulties in the compounding of curdlan and gelatin. At present, there are no relevant literatures and patents on the preparation method and performance evaluation of curdlan-gelatin composite hydrogels. Summary of the Invention

[0006] Aiming at the deficiencies of the prior art, the present invention aims to provide a high-strength gelatin-curdlan hydrogel and its preparation method. Using two natural macromolecules as raw materials, through high-temperature rapid mixing annealing and solvent conversion, curdlan is driven to form nanofiber structures in gelatin, forming an interpenetrating network structure hydrogel with nanofibers. The composite hydrogel prepared by the present invention has higher strength than a pure gelatin hydrogel, has high biocompatibility, and its preparation process is simple and rapid, avoiding the use of toxic cross-linking agents and synthetic macromolecules, and has significant application prospects in the field of biomedical materials.

[0007] To achieve the above object, the present invention adopts the following technical solutions:

[0008] The first object of the present invention is to provide a preparation method of a high-strength gelatin-curdlan hydrogel, comprising the following steps:

[0009] (1) Preparation of a gelatin aqueous solution: Weigh gelatin, add distilled water, stir under heating conditions, and after fully dissolving, prepare a gelatin aqueous solution with a concentration of 10 - 60 g / L;

[0010] (2) Preparation of a curdlan dimethyl sulfoxide solution: Weigh curdlan, add dimethyl sulfoxide, stir under heating conditions, and after fully dissolving, prepare a curdlan dimethyl sulfoxide solution with a concentration of 25 - 35 g / L;

[0011] (3) Preparation of gelatin - curdlan organic gel: Heat the gelatin aqueous solution prepared in step (1) to 90 - 100 °C, heat the curdlan dimethyl sulfoxide solution prepared in step (2) to 90 - 105 °C, mix the two high - temperature solutions in equal volume, and perform slow annealing. When the temperature drops to around room temperature, a gelatin - curdlan composite organic gel is obtained;

[0012] (4) Removal of organic solvents in the gel: Immerse the gelatin - curdlan composite organic gel prepared in step (3) in distilled water to remove the organic solvents in the gel;

[0013] (5) Preparation of high - strength gelatin - curdlan hydrogel: Dry the gelatin - curdlan hydrogel prepared in step (4), and fully swell the dried gel in distilled water to obtain a high - strength gelatin - curdlan hydrogel.

[0014] Preferably, in the preparation of the gelatin aqueous solution in step (1), the heating temperature is 40 - 50 °C, and stir for 1 - 5 h.

[0015] Preferably, in the preparation of the curdlan dimethyl sulfoxide solution in step (2), the heating temperature is 60 - 70 °C, and stir for 4 - 8 h.

[0016] Preferably, in step (3), the temperature of slow annealing is reduced from 90 - 105 °C to 20 - 30 °C.

[0017] Preferably, the removal of organic solvents in step (4) includes: Immerse the gelatin - curdlan composite organic gel prepared in step (3) in distilled water for 12 - 48 h, change the water 3 - 5 times during this period, and replace the dimethyl sulfoxide in the gel with water.

[0018] Preferably, the drying method in step (5) is air - drying at room temperature.

[0019] Preferably, in the swelling process of step (5), the volume ratio of the gelatin - curdlan hydrogel to distilled water is 1:1 - 2.

[0020] Another object of the present invention is to provide a high - strength gelatin - curdlan hydrogel prepared by the above - mentioned preparation method.

[0021] Design principle of the high - strength gelatin - curdlan hydrogel of the present invention:

[0022] The present invention utilizes temperature and solvent parameters to drive the self-assembly of gelatin - curdlan into a high-strength interpenetrating network hydrogel. Different from the principle of forming a composite hydrogel by simple mixing, the present invention controls the parameters of temperature and solvent to enable the two polymers to undergo renaturation self-assembly at different temperatures, forming a fibrous gelatin hydrogel material. Among them, curdlan exists in the form of nanofibers in the composite material, greatly improving the strength of the composite material. Based on the publicly available data, the temperature for curdlan to form nanofibers is about 100 °C, while the temperature for gelatin to form a gel is about 40 °C. In theory, an interpenetrating network hydrogel material can be constructed by means of high-temperature annealing. However, due to the low solubility of curdlan in water, the solvent environment selected in this preparation scheme is an aqueous solution containing dimethyl sulfoxide. This aqueous solution is more conducive to curdlan forming nanofibers without hindering the gelation of gelatin. By mixing a curdlan dimethyl sulfoxide solution and a gelatin aqueous solution at high temperature and then annealing the mixture, a fibrous gelatin-curdlan composite material is obtained.

[0023] Therefore, the present invention uses two natural polymers, gelatin and curdlan, as raw materials. Through high-temperature rapid mixing annealing and solvent conversion, it drives curdlan to form a nanofiber structure in gelatin, forming an interpenetrating network structure hydrogel with nanofibers. This composite hydrogel has higher strength than a simple gelatin hydrogel and has high biocompatibility, showing significant application prospects in the field of biomedical materials.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] (1) The present invention provides a preparation method for a high-strength gelatin-based hydrogel. Using gelatin and curdlan as raw materials, through temperature and denaturation-renaturation regulation, gelatin and curdlan are compounded to form a high-strength natural gelatin-based hydrogel. Moreover, the preparation method is simple in operation, low in cost, and can be promoted and produced on a large scale.

[0026] (2) The present invention avoids the use of synthetic polymers and toxic cross-linking agents, retains the good biological activity of gelatin, and the prepared high-strength gelatin-curdlan hydrogel has excellent mechanical properties and biocompatibility.

[0027] (3) The present invention provides a new idea and method for preparing a high-strength gelatin-based hydrogel, which helps the development and utilization of hydrogel materials for their application in fields such as biomaterials and tissue engineering. Description of the Drawings

[0028] Figure 1 It is a test chart of the tensile stress-strain curve of the gelatin-curdlan hydrogel prepared by the method of the present invention and the cross-linked gelatin hydrogel;

[0029] Figure 2Cytotoxicity test results of the gelatin - curdlan hydrogel prepared by the method of the present invention. Detailed implementation manners

[0030] The above - mentioned content of the present invention will be further described in detail through the following specific implementation manners in the form of examples. However, it should not be understood that the scope of the above - mentioned subject matter of the present invention is limited to the following examples.

[0031] Example 1 Preparation of the high - strength gelatin - curdlan composite hydrogel of the present invention

[0032] (1) Preparation of the gelatin aqueous solution: Weigh 0.6 g of gelatin into a beaker, add 10 mL of distilled water, and stir at 40 °C for 3 h. After complete dissolution, a gelatin aqueous solution with a concentration of 60 g / L is prepared.

[0033] (2) Preparation of the curdlan dimethyl sulfoxide solution: Weigh 0.3 g of curdlan into a beaker, add 10 mL of dimethyl sulfoxide, and stir at 65 °C for 4 h. After complete dissolution, a curdlan dimethyl sulfoxide solution with a concentration of 30 g / L is prepared.

[0034] (3) Preparation of the gelatin - curdlan organogel: Heat the gelatin aqueous solution prepared in step (1) to 100 °C, heat the curdlan dimethyl sulfoxide solution prepared in step (2) to 100 °C, mix the two high - temperature solutions in equal volumes, and slowly anneal until the temperature drops to about room temperature to obtain the gelatin - curdlan composite organogel.

[0035] (4) Removal of the organic solvent in the gel: Immerse the gelatin - curdlan composite organogel prepared in step (3) in distilled water for 24 h, and change the water 3 times during this period to remove the organic solvent in the gel.

[0036] (5) Preparation of the high - strength gelatin - curdlan hydrogel: Dry the gelatin - curdlan hydrogel prepared in step (4) at room temperature, and fully swell the dried gel in distilled water with a volume ratio of 1:1 to obtain the high - strength gelatin - curdlan hydrogel.

[0037] Example 2 Preparation of the high - strength gelatin - curdlan composite hydrogel of the present invention

[0038] (1) Preparation of the gelatin aqueous solution: Weigh 0.5 g of gelatin into a beaker, add 10 mL of distilled water, and stir at 40 °C for 3 h. After complete dissolution, a gelatin aqueous solution with a concentration of 50 g / L is prepared.

[0039] (2) Preparation of the curdlan dimethyl sulfoxide solution: Weigh 0.3 g of curdlan into a beaker, add 10 mL of dimethyl sulfoxide, and stir at 60 °C for 8 h. After complete dissolution, a curdlan dimethyl sulfoxide solution with a concentration of 30 g / L is prepared.

[0040] (3) Preparation of gelatin - curdlan organic gel: Heat the gelatin aqueous solution prepared in step (1) to 100 °C, heat the curdlan dimethyl sulfoxide solution prepared in step (2) to 102 °C, mix the two high - temperature solutions in equal volumes, and slowly anneal. When the temperature drops to about room temperature, a gelatin - curdlan composite organic gel is obtained;

[0041] (4) Removal of organic solvents in the gel: Immerse the gelatin - curdlan composite organic gel prepared in step (3) in distilled water for 48 h, changing the water 3 times during this period to remove the organic solvents in the gel;

[0042] (5) Preparation of high - strength gelatin - curdlan hydrogel: Air - dry the gelatin - curdlan hydrogel prepared in step (4) at room temperature, and fully swell the dried gel in distilled water with a volume ratio of 1:1 to obtain a high - strength gelatin - curdlan hydrogel.

[0043] Example 3 Preparation of the high - strength gelatin - curdlan composite hydrogel of the present invention

[0044] (1) Preparation of gelatin aqueous solution: Weigh 0.4 g of gelatin into a beaker, add 10 mL of distilled water, stir at 45 °C for 4 h. After complete dissolution, a gelatin aqueous solution with a concentration of 40 g / L is obtained;

[0045] (2) Preparation of curdlan dimethyl sulfoxide solution: Weigh 0.25 g of curdlan into a beaker, add 10 mL of dimethyl sulfoxide, stir at 65 °C for 6 h. After complete dissolution, a curdlan dimethyl sulfoxide solution with a concentration of 25 g / L is obtained;

[0046] (3) Preparation of gelatin - curdlan organic gel: Heat the gelatin aqueous solution prepared in step (1) to 95 °C, heat the curdlan dimethyl sulfoxide solution prepared in step (2) to 95 °C, mix the two high - temperature solutions in equal volumes, and slowly anneal. When the temperature drops to about room temperature, a gelatin - curdlan composite organic gel is obtained;

[0047] (4) Removal of organic solvents in the gel: Immerse the gelatin - curdlan composite organic gel prepared in step (3) in distilled water for 36 h, changing the water 5 times during this period to remove the organic solvents in the gel;

[0048] (5) Preparation of high - strength gelatin - curdlan hydrogel: Air - dry the gelatin - curdlan hydrogel prepared in step (4) at room temperature, and fully swell the dried gel in distilled water with a volume ratio of 1:1.5 to obtain a high - strength gelatin - curdlan hydrogel.

[0049] Example 4 Preparation of the high - strength gelatin - curdlan composite hydrogel of the present invention

[0050] (1) Preparation of gelatin aqueous solution: Weigh 0.6 g of gelatin into a beaker, add 10 mL of distilled water, stir for 3 h under heating at 45 °C, and after complete dissolution, a gelatin aqueous solution with a concentration of 60 g / L is obtained;

[0051] (2) Preparation of curdlan dimethyl sulfoxide solution: Weigh 0.3 g of curdlan into a beaker, add 10 mL of dimethyl sulfoxide, stir for 4 h under heating at 70 °C, and after complete dissolution, a curdlan dimethyl sulfoxide solution with a concentration of 30 g / L is obtained;

[0052] (3) Preparation of gelatin-curdlan organogel: Heat the gelatin aqueous solution prepared in step (1) to 105 °C, heat the curdlan dimethyl sulfoxide solution prepared in step (2) to 100 °C, mix the two high-temperature solutions in equal volume, and perform slow annealing. When the temperature drops to around room temperature, a gelatin-curdlan composite organogel is obtained;

[0053] (4) Removal of organic solvents in the gel: Immerse the gelatin-curdlan composite organogel prepared in step (3) in distilled water for 35 h, and change the water 4 times during this period to remove the organic solvents in the gel;

[0054] (5) Preparation of high-strength gelatin-curdlan hydrogel: Dry the gelatin-curdlan hydrogel prepared in step (4) at room temperature, and fully swell the dried gel in distilled water with a volume ratio of 1:2 to obtain a high-strength gelatin-curdlan hydrogel.

[0055] Example 5 Preparation of the high-strength gelatin-curdlan composite hydrogel of the present invention

[0056] (1) Preparation of gelatin aqueous solution: Weigh 0.2 g of gelatin into a beaker, add 10 mL of distilled water, stir for 3 h under heating at 45 °C, and after complete dissolution, a gelatin aqueous solution with a concentration of 20 g / L is obtained;

[0057] (2) Preparation of curdlan dimethyl sulfoxide solution: Weigh 0.35 g of curdlan into a beaker, add 10 mL of dimethyl sulfoxide, stir for 4 h under heating at 65 °C, and after complete dissolution, a curdlan dimethyl sulfoxide solution with a concentration of 35 g / L is obtained;

[0058] (3) Preparation of gelatin-curdlan organogel: Heat the gelatin aqueous solution prepared in step (1) to 100 °C, heat the curdlan dimethyl sulfoxide solution prepared in step (2) to 95 °C, mix the two high-temperature solutions in equal volume, and perform slow annealing. When the temperature drops to around room temperature, a gelatin-curdlan composite organogel is obtained;

[0059] (4) Removal of organic solvents in the gel: Soak the gelatin - curdlan composite organic gel prepared in step (3) in distilled water for 48 h, changing the water 3 times during this period to remove the organic solvents in the gel;

[0060] (5) Preparation of high - strength gelatin - curdlan hydrogel: Dry the gelatin - curdlan hydrogel prepared in step (4) at room temperature, and fully swell the dried gel in distilled water with a volume ratio of 1:1.5 to obtain a high - strength gelatin - curdlan hydrogel.

[0061] Example 6 Preparation of the high - strength gelatin - curdlan composite hydrogel of the present invention

[0062] (1) Preparation of gelatin aqueous solution: Weigh 0.45 g of gelatin into a beaker, add 10 mL of distilled water, stir at 45 °C for 3 h, and after complete dissolution, prepare a gelatin aqueous solution with a concentration of 45 g / L;

[0063] (2) Preparation of curdlan dimethyl sulfoxide solution: Weigh 0.25 g of curdlan into a beaker, add 10 mL of dimethyl sulfoxide, stir at 60 °C for 4 h, and after complete dissolution, prepare a curdlan dimethyl sulfoxide solution with a concentration of 25 g / L;

[0064] (3) Preparation of gelatin - curdlan organic gel: Heat the gelatin aqueous solution prepared in step (1) to 100 °C, heat the curdlan dimethyl sulfoxide solution prepared in step (2) to 105 °C, mix the two high - temperature solutions in equal volume, and slowly anneal, reducing the temperature to about room temperature to obtain a gelatin - curdlan composite organic gel;

[0065] (4) Removal of organic solvents in the gel: Soak the gelatin - curdlan composite organic gel prepared in step (3) in distilled water for 36 h, changing the water 5 times during this period to remove the organic solvents in the gel;

[0066] (5) Preparation of high - strength gelatin - curdlan hydrogel: Dry the gelatin - curdlan hydrogel prepared in step (4) at room temperature, and fully swell the dried gel in distilled water with a volume ratio of 1:1 to obtain a high - strength gelatin - curdlan hydrogel.

[0067] Comparative Example 1 Cross - linked gelatin hydrogel

[0068] Prepare the cross - linked gelatin material according to the method recorded in the literature (References: Wan Yizao, Wang Yulin, Zhou Fugang, etc. Study on the properties of glutaraldehyde vapor - cross - linked gelatin materials [N]. Journal of Functional Polymers. December 1999.).

[0069] Experiment 1 Mechanical property test

[0070] Tensile stress-strain tests and moisture content tests were carried out on the high-strength gelatin - curdlan composite hydrogels and crosslinked gelatin hydrogels prepared in Examples 1 - 6 of the present invention (Reference: Wan Yizao, Wang Yulin, Zhou Fugang, etc. Study on the properties of glutaraldehyde vapor crosslinked gelatin materials [N]. Journal of Functional Polymers. December 1999.).

[0071] (1) The mechanical properties were tested according to the tensile stress-strain test method described in GB / T 528 - 2009 "Determination of Tensile Stress-Strain Properties of Vulcanized Rubber or Thermoplastic Rubber", including the following steps:

[0072] The gel samples of Examples 1 - 6 and the crosslinked gelatin hydrogel of Comparative Example 1 were cut into cuboids with dimensions of 1 cm × 5 cm × 0.2 cm (n = 3). The two ends of the gel were fixed on an electronic universal testing machine and tested at a speed of 0.1 mm / s, and the tensile stress-strain curve of the gel sample was recorded. The fracture strain was defined as the change in the length of the hydrogel part between the two clips. The calculation formula for the fracture stress is σf = load / S, where S refers to the cross-sectional area of the hydrogel sample.

[0073] (2) The moisture content of the hydrogel was tested according to the moisture content test method described in GB 5009.3—2016 "Determination of Moisture Content in Foods", including the following steps:

[0074] About 2 g of the hydrogels prepared in Examples 1 - 6 and the crosslinked gelatin hydrogel of Comparative Example 1 were weighed respectively, and the wet weight W1 was recorded. Then they were placed in an oven at 60 °C for 48 h. After the water in the hydrogel was completely dried, they were weighed with an analytical balance and recorded as the dry weight W2. The moisture content was calculated by the formula. The formula is as follows:

[0075]

[0076] Experimental results: The test results of the mechanical properties are shown in Table 1, and the tensile stress-strain curves are as Figure 1 shown. From the data in Table 1 and Figure 1 it can be seen that the high-strength gelatin - curdlan composite hydrogels prepared by the method of the present invention are far superior to the crosslinked gelatin hydrogels in terms of tensile stress, tensile strain and moisture content, etc., and have excellent mechanical properties.

[0077] Table 1 Test Results of Mechanical Properties and Moisture Content

[0078]

[0079] Experiment 2 Biocompatibility Test

[0080] The cytotoxicity of the high-strength gelatin - curdlan composite hydrogels prepared in Examples 1 - 6 of the present invention and the crosslinked gelatin hydrogel of Comparative Example 1 (Reference: Wan Yizao, Wang Yulin, Zhou Fugang, etc. Study on the properties of glutaraldehyde vapor crosslinked gelatin materials [N]. Journal of Functional Polymers. December 1999.) was detected. The experimental method referred to the extraction solution test of national standard GB16886.5 - 2017 to evaluate the cytotoxicity of the hydrogel samples.

[0081] First, the sterilized hydrogel samples were immersed in cell culture medium to prepare an extraction solution with a concentration of 1 g / mL for standby. Then, referring to the CCK8 method in national standard GB16886.5 - 2017, the cytotoxicity of the hydrogel extraction solution to BALB / c 3T3 cells was detected. Among them, the high-strength gelatin - curdlan composite hydrogels prepared in Examples 1 - 6 of the present invention and the crosslinked gelatin hydrogel sample of Comparative Example 1 were used as the experimental groups, and the blank culture dish without the addition of the extraction solution was used as the control group.

[0082] The cytotoxicity of the hydrogel samples was evaluated by the CCK8 method. First, after sterilizing the hydrogel samples, they were immersed in cell culture medium to prepare an extraction solution with a concentration of 1 g / mL for standby. Cells in the logarithmic growth phase were inoculated into a 96-well plate at a density of 1×10 3 cells / well, and after culturing overnight, the original culture medium was discarded. Then, 100 μL of the sample extraction solution was added to each well and cultured for 1, 3, and 7 days respectively. In the control group, 100 μL of cell culture medium was added to each well. After the culture ended, the original culture solution was discarded, and 10 μL of CCK8 working solution (serum-free medium: CCK8 = 9:1) was added to each well, and the mixture was incubated for 1.5 h in the dark. Finally, the absorbance at a wavelength of 450 nm of each well was measured, and the cell survival rate of each group of samples was calculated according to the following formula:

[0083]

[0084] where A 样品 is the absorbance of the hydrogel sample; A 空白 is the absorbance of the blank well; A 对照 is the absorbance of the control group.

[0085] The experimental results are as Figure 2 shown. It can be seen from Figure 2 that the cell survival rates of the gelatin - curdlan hydrogels prepared in Examples 1 - 6 of the present invention are all greater than 95%. The experimental results are far better than those of the crosslinked gelatin hydrogel, indicating that the gelatin-based hydrogels prepared by the method of the present invention have good cell compatibility.

[0086] The above embodiments are only illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Any person familiar with this technology can modify or change the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by those with ordinary knowledge in the technical field without departing from the spirit and technical idea disclosed by the present invention should still be covered by the claims of the present invention.

Claims

1. A preparation method of a high-strength gelatin - curdlan hydrogel, characterized in that, It includes the following steps: (1) Preparation of gelatin aqueous solution: Weigh gelatin, add distilled water, stir under heating conditions, and after complete dissolution, obtain a gelatin aqueous solution with a concentration of 10 - 60 g / L; (2) Preparation of curdlan dimethyl sulfoxide solution: Weigh curdlan, add dimethyl sulfoxide, stir under heating conditions, and after complete dissolution, obtain a curdlan dimethyl sulfoxide solution with a concentration of 25 - 35 g / L; (3) Preparation of gelatin - curdlan organic gel: Heat the gelatin aqueous solution prepared in step (1) to 90 - 100 °C, heat the curdlan dimethyl sulfoxide solution prepared in step (2) to 90 - 105 °C, mix the two high - temperature solutions in equal volume, perform slow annealing, and when the temperature drops to around room temperature, obtain a gelatin - curdlan composite organic gel; (4) Removal of organic solvents in the gel: Immerse the gelatin - curdlan composite organic gel prepared in step (3) in distilled water to remove the organic solvents in the gel; (5) Preparation of high - strength gelatin - curdlan hydrogel: Dry the gelatin - curdlan hydrogel prepared in step (4), and fully swell the dried gel in distilled water to obtain a high - strength gelatin - curdlan hydrogel.

2. The preparation method according to claim 1, characterized in that, In the preparation of the gelatin aqueous solution in step (1), the heating temperature is 40 - 50 °C, and the stirring time is 1 - 5 h.

3. The preparation method according to claim 1, characterized in that, In the preparation of the curdlan dimethyl sulfoxide solution in step (2), the heating temperature is 60 - 70 °C, and the stirring time is 4 - 8 h.

4. The preparation method according to claim 1, characterized in that, In step (3), the temperature of slow annealing decreases from 90 - 105 °C to 20 - 30 °C.

5. The preparation method according to claim 1, characterized in that, The removal of organic solvents in step (4) includes: Immerse the gelatin - curdlan composite organic gel prepared in step (3) in distilled water for 12 - 48 h, change the water 3 - 5 times during this period, and replace the dimethyl sulfoxide in the gel with water.

6. The preparation method according to claim 1, wherein, The drying method in step (5) is air - drying at room temperature.

7. The preparation method according to claim 1, characterized in that, In the swelling process of step (5), the volume ratio of the gelatin - curdlan hydrogel to distilled water is 1:1 - 2.

8. A high - strength gelatin - curdlan hydrogel prepared by the preparation method according to claim 1.

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