An interpenetrating network hydrogel and its application in preparing a cell culture scaffold

Abstract

The present invention relates to an interpenetrating network hydrogel, which is composed of an aliphatic polyester, 2,3-dihydroxypropyl acrylate with a weight 0.4-0.6 times that of the aliphatic polyester, N,N'-methylenebisacrylamide with a weight 0.05-0.1 times that of the aliphatic polyester, and potassium persulfate with a weight 0.05-0.1 times that of the aliphatic polyester according to a weight ratio. Among them, the aliphatic polyester is obtained by ring-opening polymerization of diglycolic anhydride, an epoxy monomer, and a crosslinked epoxy monomer. The interpenetrating network hydrogel of the present invention has good elastic modulus and swelling properties, and also has the advantages of low cytotoxicity, good biocompatibility, and high cell affinity, and is suitable for preparing cell culture scaffolds.

Description

Technical Field

[0001] The present invention relates to polymer gels, specifically to interpenetrating network hydrogels, which can be used to prepare cell culture scaffolds. Background Art

[0002] Interpenetrating network hydrogels are formed by the entanglement and interpenetration of two or more polymers, and at least contain a network structure crosslinked by chemical bonds. Interpenetrating network hydrogels have structural and morphological characteristics such as special cell-like structures, interfacial interpenetration, and biphasic continuity, which enable them to produce synergistic effects in terms of performance or function, prevent phase separation, and improve the mechanical properties of the hydrogels. The literature (Carbohydrate Polymers, 2022, 277, 118828) prepared a hybrid interpenetrating polymer network hydrogel based on covalently crosslinked HA (HA-BDDE) and HA-poly(N-isopropylacrylamide) (HA-pNIPAM), and used it as a cell carrier for nucleus pulposus repair. Song Yizhe et al. prepared a collagen / calcium alginate interpenetrating network hydrogel by solution blending method for cell culture (Song Yizhe, Ren Ying, Lou Ruyun, Wang Xiuli, Yu Weiting, Construction of collagen / calcium alginate interpenetrating network hydrogel and its influence on cell behavior, Functional Materials, 2016, 47(11), 11136). Hu Xinyu et al. added tannic acid (TA) from Trogopterus xanthipes Maxim in the poly(N,N-dimethylacrylamide) (PDMAA) network, and designed and synthesized a series of novel TA / PDMAA semi-interpenetrating network hydrogels for cell culture and tissue engineering (Hu Xinyu, Wang Yongmei, Zhang Liangliang, Xu Man, Preparation of tannic acid from Trogopterus xanthipes Maxim / poly(N,N-dimethylacrylamide) hydrogel and its cell adhesion properties, Journal of Forestry Engineering, 2017, 2(06), 37). Zhang Feifei et al. prepared a three-dimensional polyethylene glycol dipropionate (PEGDA) and silk fibroin interpenetrating polymer network hydrogel by ultraviolet light curing method. The experimental results showed that the interpenetrating network hydrogel formed by photocuring exhibited good cell compatibility and had broad application potential in the fields of tissue engineering and drug delivery (Zhang Feifei, Wang Tongtong, Li Qingsong, Gao Peng, Hu Jianchen, Synthesis and characterization of photo-crosslinked PEGDA / silk fibroin interpenetrating polymer network hydrogel, Light Industry Science and Technology, 2018, 34(09), 111). However, the above interpenetrating network hydrogels have disadvantages such as poor mechanical properties and difficulty in processing and forming, which limit their practical applications. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide an interpenetrating network hydrogel with good hydrophilicity, biocompatibility and mechanical properties.

[0004] The technical solution of the present invention to solve the above problems is as follows:

[0005] An interpenetrating network hydrogel, which is composed of an aliphatic polyester, 2,3-dihydroxypropyl acrylate with a weight 0.4 - 0.6 times that of the aliphatic polyester, N,N'-methylenebisacrylamide with a weight 0.05 - 0.1 times that of the aliphatic polyester, and potassium persulfate with a weight 0.05 - 0.1 times that of the aliphatic polyester according to the weight ratio; wherein,

[0006] The aliphatic polyester is prepared by the following method: Diethylene glycol anhydride, an epoxy monomer, a crosslinked epoxy monomer, and zinc acetate are added to DMF according to the molar ratio of diethylene glycol anhydride:epoxy monomer:crosslinked epoxy monomer:zinc acetate = 1:1:0.05 - 0.1:0.001 - 0.005. Under nitrogen protection, the temperature is raised to 60 - 80 °C for ring-opening polymerization reaction for 5 - 10 h, then cooled to room temperature, and precipitated in n-hexane. The precipitate is collected to obtain the aliphatic polyester; the aliphatic polyester has a network structure, and its weight-average molecular weight is 1500 - 4000;

[0007] The epoxy monomer is octyl glycidyl ether and / or 2-ethylhexyl glycidyl ether;

[0008] The crosslinked epoxy monomer is one or more of pentaerythritol glycidyl ether, glycidyl ether, trimethylolpropane triglycidyl ether, and polyethylene glycol diglycidyl ether.

[0009] In the above solution, the temperature of the ring-opening polymerization reaction is preferably 70 °C, and the reaction time is preferably 8 h.

[0010] In the above solution, the weight-average molecular weight of the aliphatic polyester is preferably 2000 - 3000.

[0011] The interpenetrating network hydrogel of the present invention is prepared by the following method: The aliphatic polyester, 2,3-dihydroxypropyl acrylate, N,N'-methylenebisacrylamide, and potassium persulfate are added to separately taken DMF, and mixed evenly; React at 60 - 80 °C for 6 - 8 h, soak and wash repeatedly with distilled water, purify sufficiently, and dry to constant weight to obtain the interpenetrating network hydrogel.

[0012] In the interpenetrating network hydrogel of the present invention, the aliphatic polyester contained in the network structure is formed by ring-opening polymerization of diglycolic anhydride, epoxy monomer, cross-linked epoxy monomer and zinc acetate dissolved in DMF. From the above preparation method of the aliphatic polyester, it can be seen that in the ring-opening polymerization reaction system, the cross-linked epoxy monomer is used as a cross-linking agent, and the ring-opening polymerization reaction is carried out under the condition that the molar ratio of the total epoxy group functional group to the acid anhydride functional group is greater than 1.15. Obviously, the obtained polymer is an aliphatic polyester with a network structure. Further, from the above preparation method of the interpenetrating network hydrogel, in DMF, 2,3-dihydroxypropyl acrylate and N,N'-methylenebisacrylamide are dispersed and cross-linked together through the network structure of the aliphatic polyester, and then cured under the action of initiator potassium persulfate to form an interpenetrating network structure.

[0013] The interpenetrating network hydrogel of the present invention has the advantages of good elastic modulus, swelling performance, low cytotoxicity, good biocompatibility and high cell affinity, and is suitable for preparing cell culture scaffolds. Specific embodiments

[0014] The preparation method and its effects of the present invention will be further described in detail with specific examples below.

[0015] Example 1

[0016] 1. Synthesis of aliphatic polyester

[0017] Take 10 mmol of diglycolic anhydride, 10 mmol of octyl glycidyl ether, 0.5 mmol of pentaerythritol glycidyl ether and 0.01 mmol of zinc acetate, add them to 10 mL of DMF, heat to 60 °C under nitrogen protection for ring-opening polymerization reaction for 10 h, cool to room temperature, and precipitate in n-hexane to obtain the aliphatic polyester.

[0018] The weight-average molecular weight and number-average molecular weight of the obtained aliphatic polyester were measured using a Jasco Gulliver system (PU-980, CO-965, RI-930, and UV-1570) gel permeation chromatograph. Equipped with polystyrene gel columns (Shodex columns K804, K805, and J806), using DMF as the eluent, polystyrene as the standard for calibration, and measuring at 30 °C. The detection results showed that the weight-average molecular weight of the aliphatic polyester was 3407.

[0019] The above aliphatic polyester is obtained by ring-opening copolymerization of diglycol anhydride, octyl glycidyl ether, and pentaerythritol glycidyl ether. Among them, pentaerythritol glycidyl ether is a polyfunctional raw material and acts as a cross-linking agent, resulting in the formation of a cross-linked structure in the polymerization product. Moreover, among the reaction components, diglycol anhydride contains 10 mmol of acid anhydride functional groups, octyl glycidyl ether contains 10 mmol of epoxy functional groups, and pentaerythritol glycidyl ether contains 2 mmol of epoxy functional groups, with a total of 12 mmol of epoxy functional groups. The molar ratio between the acid anhydride functional groups and the epoxy functional groups is 1:1.2, and the polymer obtained by ring-opening copolymerization under this condition is a network structure.

[0020] 2. Interpenetrating network hydrogel

[0021] 2.1. Synthesis of interpenetrating network hydrogel

[0022] Take 10 g of the above-synthesized aliphatic polyester, 6 g of 2,3-dihydroxypropyl acrylate, 0.5 g of N,N'-methylenebisacrylamide, and 0.05 g of potassium persulfate, add them to 20 mL of DMF, mix evenly, load into a mold, and react at 60 °C for 7 h; then soak and wash repeatedly with distilled water, purify, and dry to constant weight to obtain an interpenetrating network hydrogel.

[0023] In the above reaction, 2,3-dihydroxypropyl acrylate and the cross-linking agent N,N'-methylenebisacrylamide undergo cross-linking polymerization under the initiation of potassium persulfate to form an interpenetrating network structure with the network-structured aliphatic polyester.

[0024] 2.2. Properties of interpenetrating network hydrogel

[0025] Swelling ratio of interpenetrating network hydrogel

[0026] At room temperature, take the interpenetrating network hydrogel, weigh it precisely to obtain W o ; soak it in water at room temperature until it reaches swelling equilibrium, wipe off the excess water on the surface of the scaffold with filter paper, and measure the mass of the hydrogel again to obtain W e , and calculate the absorption rate of the interpenetrating network hydrogel according to the following formula. Swelling ratio (%) = (We - W0) / W0. The swelling ratio is obtained as 2015%.

[0027] Mechanical properties of interpenetrating network hydrogel

[0028] Detect the prepared interpenetrating network hydrogel on a Zwick / Roell 2202 universal material testing machine (Zwick Company, Germany).

[0029] Detect according to the above method, and the elastic modulus of the prepared interpenetrating network hydrogel is 3.17 MPa, and the tensile strength is 2.64 Mpa.

[0030] 3. Cell experiment

[0031] 3.1. Cell seeding

[0032] Cut the prepared interpenetrating network hydrogel sample into 24-well size, add PBS to soak it, wait for it to reach swelling equilibrium, and wash it with sterilized PBS. Then put it into a sterilized bottle containing PBS, soak for 24 h, and place it at 4 °C for standby.

[0033] A 24-well plate was used for cell culture in the experiment.

[0034] Put the interpenetrating network hydrogel samples into 24-well plates respectively. Add the cultured mouse fibroblast L929 cells into the wells containing the interpenetrating network hydrogel (2.0×10 6 cells / 100 uL / well), and culture them in an incubator at 37 °C and 5% CO2 for 4 hours to allow the cells to adhere better. Then add 1 mL of culture medium to each culture well, and culture it in an incubator at 37 °C and 5% CO2. Replace the culture medium every 2 days.

[0035] 3.2. Evaluation of cell viability

[0036] Take out the 24-well culture plates at 1 d, 3 d, and 7 d respectively. Add 80 uL of MTT solution to each well, and put it into the incubator to continue culturing for 4 h. Aspirate the culture medium, add 750 uL of isopropanol hydrochloride solution (0.4 mol / L) to each well, incubate in the incubator for 15 min, pipette and mix well, then take 200 uL from each well and transfer it into a 96-well culture plate. Use a fully automatic microplate reader to detect the light absorption value (OD value) of each well at 540 nm.

[0037] Cell viability % = ((OD of test cells - OD of blank) / (OD of control cells - OD of blank)) × 100

[0038] Detect according to the above method, and the cell viability of the prepared interpenetrating network hydrogel is shown in Table 1.

[0039] Table 1 Cell activity of tissue engineering scaffolds

[0040] Time (days) 1 3 7 Cell viability % 98.4±3.4 106±6.7 113±7.3

[0041] It can be seen from Table 1 that the prepared interpenetrating network hydrogel has low cytotoxicity, high cell affinity, and good cell adhesion.

[0042] Example 2

[0043] 1. Synthesis of aliphatic polyester

[0044] 10 mmol of diglycolic anhydride, 5 mmol of octyl glycidyl ether, 5 mmol of 2-ethylhexyl glycidyl ether, 0.2 mmol of glycidyl ether, 0.6 mmol of pentaerythritol glycidyl ether, 0.2 mmol of polyethylene glycol diglycidyl ether and 0.05 mmol of zinc acetate were added to 20 mL of DMF. Under nitrogen protection, the temperature was raised to 80 °C for ring-opening polymerization for 10 h, and then cooled to room temperature. The resulting aliphatic polyester was obtained by precipitation in n-hexane.

[0045] The aliphatic polyester prepared was detected by the same method as in Example 1. The detection result showed that the weight-average molecular weight of the aliphatic polyester was 4003.

[0046] The above-mentioned aliphatic polyester was obtained by ring-opening copolymerization of diglycolic anhydride, octyl glycidyl ether, 2-ethylhexyl glycidyl ether, glycidyl ether, pentaerythritol glycidyl ether and polyethylene glycol diglycidyl ether. Among them, glycidyl ether, pentaerythritol glycidyl ether and polyethylene glycol diglycidyl ether are multi-functional raw materials and act as cross-linking agents, resulting in the formation of a cross-linked structure in the polymerization product. Moreover, in the reaction components, diglycolic anhydride contains 10 mmol of acid anhydride functional groups. Octyl glycidyl ether contains 5 mmol of epoxy functional groups, 2-ethylhexyl glycidyl ether contains 5 mmol of epoxy functional groups, glycidyl ether contains 0.6 mmol of epoxy functional groups, pentaerythritol glycidyl ether contains 2.4 mmol of epoxy functional groups, and polyethylene glycol diglycidyl ether contains 0.4 mmol of epoxy functional groups. The total amount of epoxy functional groups is 13.4 mmol. The molar ratio between the acid anhydride functional groups and the epoxy functional groups is 1:1.34. Under this condition, the polymer obtained by ring-opening copolymerization is a network structure.

[0047] 2. Interpenetrating network hydrogel

[0048] 2.1. Synthesis of interpenetrating network hydrogel

[0049] 10 g of the above-mentioned synthesized aliphatic polyester, 6 g of 2,3-dihydroxypropyl acrylate, 1.0 g of N,N'-methylenebisacrylamide and 0.1 g of potassium persulfate were added to 20 mL of DMF, mixed evenly, loaded into a mold, and reacted at 80 °C for 6 h; then it was repeatedly soaked and washed with distilled water, purified, and dried to constant weight to obtain an interpenetrating network hydrogel.

[0050] In the above reaction, 2,3-dihydroxypropyl acrylate and the cross-linking agent N,N'-methylenebisacrylamide were cross-linked and polymerized under the initiation of potassium persulfate to form an interpenetrating network structure with the network-structured aliphatic polyester.

[0051] 2.2 Performance detection of interpenetrating network hydrogel

[0052] The swelling ratio of the prepared interpenetrating network hydrogel was detected according to the method described in Example 1 and was 2686%.

[0053] The elastic modulus of the prepared interpenetrating network hydrogel was 3.34 MPa and the tensile strength was 2.81 Mpa when detected according to the method described in Example 1.

[0054] 3.2. Evaluation of cell viability

[0055] When detected according to the method described in Example 1, the cell viability of the prepared interpenetrating network hydrogel was as shown in Table 2.

[0056] Table 2 Cell activity of the interpenetrating network hydrogel

[0057] Time (days) 1 3 7 Cell viability % 104.3±2.1 109.5±3.7 98.1±1.3

[0058] It can be seen from Table 2 that the prepared interpenetrating network hydrogel has low cytotoxicity, high cell affinity and good cell adhesion.

[0059] Example 3

[0060] 1. Synthesis of aliphatic polyester

[0061] 10 mmol of diglycolic anhydride, 10 mmol of 2-ethylhexyl glycidyl ether, 0.25 mmol of trimethylolpropane triglycidyl ether, 0.25 mmol of polyethylene glycol diglycidyl ether and 0.01 mmol of zinc acetate were added to 10 mL of DMF. Under nitrogen protection, the temperature was raised to 60 °C for ring-opening polymerization reaction for 5 h, and then cooled to room temperature. The resulting product was precipitated in n-hexane to obtain the aliphatic polyester.

[0062] The prepared aliphatic polyester was detected by the same method as in Example 1, and the weight average molecular weight of the aliphatic polyester was obtained as 1547.

[0063] The above-mentioned aliphatic polyester was obtained by ring-opening copolymerization of diglycolic anhydride, 2-ethylhexyl glycidyl ether, trimethylolpropane triglycidyl ether and polyethylene glycol diglycidyl ether. Among them, trimethylolpropane triglycidyl ether and polyethylene glycol diglycidyl ether are polyfunctional raw materials and act as cross-linking agents, resulting in the formation of a cross-linked structure in the polymerization product. Moreover, among the reaction components, diglycolic anhydride contains 10 mmol of acid anhydride functional groups, 2-ethylhexyl glycidyl ether contains 10 mmol of epoxy functional groups, polyethylene glycol diglycidyl ether contains 0.5 mmol of epoxy functional groups, and trimethylolpropane triglycidyl ether contains 0.75 mmol of epoxy functional groups. The total amount of epoxy functional groups is 11.25 mmol. The molar ratio between the acid anhydride functional group and the epoxy functional group is 1:1.125. Under this condition, the polymer obtained by ring-opening copolymerization is a network structure.

[0064] 2. Interpenetrating Network Hydrogel

[0065] 2.1. Synthesis of Interpenetrating Network Hydrogel

[0066] Take 10 g of the above-mentioned synthesized saturated aliphatic polyester, 4 g of 2,3-dihydroxypropyl acrylate, 0.5 g of N,N'-methylenebisacrylamide, and 0.05 g of potassium persulfate, add them to 10 mL of DMF, mix evenly, load into a mold, and react at 60 °C for 8 h; then soak and wash repeatedly with distilled water, purify, and dry to constant weight to obtain the interpenetrating network hydrogel.

[0067] In the above reaction, 2,3-dihydroxypropyl acrylate and the cross-linking agent N,N'-methylenebisacrylamide undergo cross-linking polymerization under the initiation of potassium persulfate to form an interpenetrating network structure with the aliphatic polyester in the network structure.

[0068] 2.2 Performance Detection of Interpenetrating Network Hydrogel

[0069] Detect according to the method described in Example 1. The swelling ratio of the prepared interpenetrating network hydrogel is 1899%.

[0070] Detect according to the method described in Example 1. The elastic modulus of the prepared interpenetrating network hydrogel is 2.61 MPa, and the tensile strength is 2.39 Mpa.

[0071] 2.3 Evaluation of Cell Viability

[0072] Detect according to the method described in Example 1. The cell viability of the prepared interpenetrating network hydrogel is shown in Table 3.

[0073] Table 3 Cell Activity of Interpenetrating Network Hydrogel

[0074] Time (days) 1 3 7 Cell viability % 100.7±1.9 98.7±2.3 105.1±3.6

[0075] It can be known from Table 3 that the prepared interpenetrating network hydrogel has low cytotoxicity, high cell affinity, and good cell adhesion.

[0076] Example 4

[0077] 1. Synthesis of Aliphatic Polyester

[0078] Add 10 mmol of diglycol anhydride, 10 mmol of octyl glycidyl ether, 0.68 mmol of trimethylolpropane triglycidyl ether, and 0.03 mmol of zinc acetate to 20 mL of DMF. Under nitrogen protection, heat to 70 °C for ring-opening polymerization reaction for 8 h, cool to room temperature, and precipitate in n-hexane to obtain the aliphatic polyester.

[0079] Detect the prepared aliphatic polyester by the same method as in Example 1. The detection result shows that the weight-average molecular weight of the aliphatic polyester is 3011.

[0080] The above aliphatic polyester is obtained by ring-opening copolymerization of diglycol anhydride, octyl glycidyl ether and trimethylolpropane triglycidyl ether. Among them, trimethylolpropane triglycidyl ether is a polyfunctional raw material and acts as a cross-linking agent, resulting in the formation of a cross-linked structure in the polymerization product. Moreover, among the reaction components, diglycol anhydride contains 10 mmol of acid anhydride functional groups, octyl glycidyl ether contains 10 mmol of epoxy functional groups, and trimethylolpropane triglycidyl ether contains 2.04 mmol of epoxy functional groups, with a total of 12.04 mmol of epoxy functional groups. The molar ratio between the acid anhydride functional groups and the epoxy functional groups is 1:1.204, and the polymer obtained by ring-opening copolymerization under this condition is a network structure.

[0081] 2. Interpenetrating network hydrogel

[0082] 2.1. Synthesis of interpenetrating network hydrogel

[0083] Take 10 g of the above-synthesized saturated aliphatic polyester, 5.3 g of 2,3-dihydroxypropyl acrylate, 0.7 g of N,N'-methylenebisacrylamide, and 0.06 g of potassium persulfate, add them to 10 mL of DMF, mix evenly, load into a mold, react at 70 °C for 7.5 h, and then soak and wash repeatedly with distilled water, purify, and dry to constant weight to obtain an interpenetrating network hydrogel.

[0084] In the above reaction, 2,3-dihydroxypropyl acrylate and the cross-linking agent N,N'-methylenebisacrylamide undergo cross-linking polymerization under the initiation of potassium persulfate to form an interpenetrating network structure with the network-structured aliphatic polyester.

[0085] 2.2 Performance detection of interpenetrating network hydrogel

[0086] Detect according to the method described in Example 1. The swelling ratio of the prepared interpenetrating network hydrogel is 2459%.

[0087] Detect according to the method described in Example 1. The elastic modulus of the prepared interpenetrating network hydrogel is 3.07 MPa, and the tensile strength is 2.62 Mpa.

[0088] 2.3. Evaluation of cell viability

[0089] Detect according to the method described in Example 1. The cell viability of the prepared interpenetrating network hydrogel is shown in Table 4.

[0090] Table 4 Cell viability of interpenetrating network hydrogel

[0091] Time (days) 1 3 7 Cell viability % 107.1±4.3 112.2±6.3 109.4±5.0

[0092] It can be seen from Table 4 that the prepared interpenetrating network hydrogel has low cytotoxicity, high cell affinity, and good cell adhesion.

[0093] Example 5

[0094] 1. Synthesis of aliphatic polyester

[0095] 10 mmol of diglycolic anhydride, 10 mmol of octyl glycidyl ether, 0.65 mmol of trimethylolpropane triglycidyl ether and 0.025 mmol of zinc acetate were added to 15 mL of DMF. Under nitrogen protection, the temperature was raised to 65 °C for ring-opening polymerization for 6 h, and then cooled to room temperature. The mixture was precipitated in n-hexane to obtain the aliphatic polyester.

[0096] The prepared aliphatic polyester was detected by the same method as in Example 1. The detection result showed that the weight-average molecular weight of the aliphatic polyester was 2209.

[0097] The above-mentioned aliphatic polyester was obtained by ring-opening copolymerization of diglycolic anhydride, octyl glycidyl ether and trimethylolpropane triglycidyl ether. Among them, trimethylolpropane triglycidyl ether is a multi-functional raw material and acts as a cross-linking agent, resulting in the formation of a cross-linked structure in the polymerization product. Moreover, in the reaction components, diglycolic anhydride contains 10 mmol of acid anhydride functional groups, octyl glycidyl ether contains 10 mmol of epoxy functional groups, and trimethylolpropane triglycidyl ether contains 1.95 mmol of epoxy functional groups, and the total amount of epoxy functional groups is 11.95 mmol. The molar ratio between the acid anhydride functional group and the epoxy functional group is 1:1.195. Under this condition, the polymer obtained by ring-opening copolymerization is a network structure.

[0098] 2. Interpenetrating network hydrogel

[0099] 2.1. Synthesis of interpenetrating network hydrogel

[0100] 10 g of the above-synthesized saturated aliphatic polyester, 5.5 g of 2,3-dihydroxypropyl acrylate, 0.65 g of N,N'-methylenebisacrylamide and 0.06 g of potassium persulfate were added to 15 mL of DMF, mixed evenly, filled into a mold, and reacted at 65 °C for 6.5 h. Then it was repeatedly soaked and washed with distilled water, purified, and dried to constant weight to obtain the interpenetrating network hydrogel.

[0101] In the above reaction, 2,3-dihydroxypropyl acrylate and the cross-linking agent N,N'-methylenebisacrylamide were cross-linked and polymerized under the initiation of potassium persulfate to form an interpenetrating network structure with the network-structured aliphatic polyester.

[0102] 2.2. Performance detection of interpenetrating network hydrogel

[0103] Detected according to the method described in Example 1, the swelling ratio of the prepared interpenetrating network hydrogel was 3057%.

[0104] Detection was carried out according to the method described in Example 1. The elastic modulus of the prepared interpenetrating network hydrogel was 2.88 MPa, and the tensile strength was 2.72 Mpa.

[0105] 2.3. Evaluation of cell viability

[0106] Detection was carried out according to the method described in Example 1. The cell viability of the prepared interpenetrating network hydrogel is shown in Table 5.

[0107] Table 5 Cell viability of the interpenetrating network hydrogel

[0108] Time (days) 1 3 7 Cell viability % 102.7±3.4 101.5±1.3 100.5±2.5

[0109] It can be seen from Table 5 that the prepared interpenetrating network hydrogel has low cytotoxicity, high cell affinity, and good cell adhesion.

[0110] Example 6 (comparative experiment)

[0111] I. Comparative experiment 1

[0112] 1. Control 1 was prepared as follows:

[0113] 6 g of 2,3-dihydroxypropyl acrylate, 0.5 g of N,N'-methylenebisacrylamide, and 0.05 g of potassium persulfate were added to 10 mL of DMF, and mixed evenly; filled into a mold, reacted at 60 °C for 8 h, then repeatedly soaked and washed with distilled water, purified, and dried to constant weight to obtain dry-state crosslinked polyacrylate.

[0114] 2. Control 2 was the aliphatic polyester prepared in Example 1.

[0115] 3. The sample was the interpenetrating network hydrogel prepared in Example 1.

[0116] 4. Detection method

[0117] The swelling ratio, elastic modulus, and tensile strength of the sample and Controls 1 and 2 were detected respectively according to the method described in Example 1. The results are shown in Table 6.

[0118] Table 6 Comparison of swelling ratio, elastic modulus, and tensile strength

[0119]

[0120]

[0121] It can be seen from Table 6 that the swelling ratio, elastic modulus, and tensile strength of the sample are significantly better than those of Controls 1 and 2.

[0122] II. Control experiment 2

[0123] 1. Control 1:

[0124] Prepare a collagen / calcium alginate interpenetrating network hydrogel according to the method described in Comparative Document 1 (Song Yizhe, Ren Ying, Lou Ruyun, Wang Xiuli, Yu Weiting, Construction of Collagen / Calcium Alginate Interpenetrating Network Hydrogel and Its Influence on Cell Behavior, Functional Materials, 2016, 47(11), 11136).

[0125] 2. Control 2:

[0126] Prepare a PEGDA / silk fibroin interpenetrating polymer network hydrogel according to the method described in Comparative Document 2 (Zhang Feifei, Wang Tongtong, Li Qingsong, Gao Peng, Hu Jianchen, Synthesis and Characterization of Photo-Crosslinked PEGDA / Silk Fibroin Interpenetrating Polymer Network Hydrogel, Light Industry Science and Technology, 2018, 34(09), 111).

[0127] 3. Sample: The interpenetrating network hydrogel prepared in Example 1.

[0128] 4. Detection method: Detect the elastic modulus and tensile strength of the sample and Controls 1 and 2 respectively according to the method described in Example 1. The results are shown in Table 7 below.

[0129] Table 7 Comparison of Elastic Modulus and Tensile Strength

[0130] Elastic modulus (Mpa) Tensile strength (Mpa) Sample 3.17 2.64 Control 1 2.53 1.61 Control 12 2.82 1.72

[0131] As can be seen from Table 7, the elastic modulus and tensile strength of the sample are significantly better than those of Controls 1 and 2.

Claims

1. An interpenetrating network hydrogel, which is composed of an aliphatic polyester, 2,3-dihydroxypropyl acrylate with a weight 0.4 - 0.6 times that of the aliphatic polyester, N,N'-methylenebisacrylamide with a weight 0.05 - 0.1 times that of the aliphatic polyester, and potassium persulfate with a weight 0.05 - 0.1 times that of the aliphatic polyester, by weight ratio; wherein, The aliphatic polyester is prepared by the following method: Add diglycolic anhydride, an epoxy monomer, a cross-linked epoxy monomer, and zinc acetate into DMF according to a molar ratio of diglycolic anhydride:epoxy monomer:cross-linked epoxy monomer:zinc acetate = 1:1:0.05 - 0.1:0.001 - 0.005, heat to 60 - 80 °C under nitrogen protection for ring-opening polymerization reaction for 5 - 10 h, cool to room temperature, add to n-hexane for precipitation, and collect the precipitate to obtain the aliphatic polyester; the aliphatic polyester is a network structure with a weight-average molecular weight of 1500 - 4000; The epoxy monomer is octyl glycidyl ether and / or 2-ethylhexyl glycidyl ether; The cross-linked epoxy monomer is one or more of glycidyl ether, trimethylolpropane triglycidyl ether, and polyethylene glycol diglycidyl ether.

2. The interpenetrating network hydrogel according to claim 1, wherein The temperature of the ring-opening polymerization reaction is 70 °C and the time is 8 h.

3. A method for preparing the interpenetrating network hydrogel according to claim 1 or 2, which consists of the following steps: Add the aliphatic polyester, 2,3-dihydroxypropyl acrylate, N,N'-methylenebisacrylamide, and potassium persulfate into separately taken DMF, mix evenly; react at 60 - 80 °C for 6 - 8 h to obtain the interpenetrating network hydrogel.

4. Use of the interpenetrating network hydrogel according to claim 1 or 2 in the preparation of a cell culture scaffold.

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