A mechanically interlocked topology hydrogel material and a preparation method thereof

Abstract

The application provides a preparation method of a mechanical interlocking topological structure hydrogel material, comprising the following steps: A) mixing a radiation-crosslinkable polymer, water and a toughening agent to obtain a hydrogel prepolymer; B) covering a radiation shielding device on the upper surface of the hydrogel prepolymer to obtain a product to be radiated; the radiation shielding device is a plate material with a uniform distribution of circular through-hole structures; C) placing the product to be radiated on the track of an electron accelerator, starting the electron accelerator to perform first radiation crosslinking, moving the plate material along different directions and performing radiation crosslinking to obtain a hydrogel material. The application also provides a mechanical interlocking topological structure hydrogel material. The preparation method provided by the application prepares four kinds of hydrogel materials with different overlapping crosslinking densities, and when subjected to external force, the topological structure presents a spring-like stretching and contraction, gradually dissipates the energy of external force from one crosslinking to four crosslinkings, and the toughness of the hydrogel is improved.

Description

Technical Field

[0001] This invention relates to the field of biomaterials technology, and in particular to a mechanically interlocked topological structure hydrogel material and its preparation method. Background Technology

[0002] Hydrogels are three-dimensional hydrophilic polymers that can swell, absorb, and retain large amounts of water while remaining insoluble in water. They are soft and resemble living tissues, possessing excellent biocompatibility and biodegradability. They are widely used in the biomedical field, such as for drug release, medical dressings, gingival tissue regeneration, and bone repair, and are one of the most promising medical materials for the future.

[0003] Hydrogels synthesized by radiation methods offer advantages such as purity, environmental friendliness, convenient processing, precise control, and lack of toxic side effects. Furthermore, irradiation crosslinking uses polymers as raw materials, resulting in the absence of small-molecule monomers and initiator residues in the product, significantly improving biocompatibility compared to other synthesis methods. Therefore, radiation-based hydrogel preparation has been widely used in the biomedical field. However, conventional radiation-prepared hydrogels generally suffer from poor mechanical strength and toughness due to the lack of an effective energy dissipation mechanism, making them unsuitable for high-intensity environments, prone to breakage, and inconvenient to handle. Therefore, providing an effective method to improve the strength, toughness, and biocompatibility of hydrogel materials is of great significance. Summary of the Invention

[0004] The technical problem solved by this invention is to provide a method for preparing a mechanically interlocked topological structure hydrogel, which can improve the toughness and strength of the hydrogel.

[0005] In view of this, this application provides a method for preparing a mechanically interlocked topological structure hydrogel material, comprising the following steps:

[0006] A) A radiation-crosslinkable polymer, water, and a toughening agent are mixed to obtain a hydrogel prepolymer;

[0007] B) Cover the upper surface of the hydrogel prepolymer with a radiation shielding device to obtain an object to be irradiated; the radiation shielding device is a plate with a uniformly distributed circular through-hole structure.

[0008] C) The object to be irradiated is placed in the electron accelerator track. The electron accelerator is turned on for the first radiation crosslinking. The plate is moved horizontally by a displacement n for the second radiation crosslinking. Then, the plate is moved vertically by a displacement n for the third radiation crosslinking. Finally, the plate is moved horizontally in the opposite direction by a displacement n for the fourth radiation crosslinking, resulting in a mechanically interlocked topology. The value of n ranges from [value missing]. R is the radius of the circular through hole, and d is the distance between adjacent circular through holes.

[0009] Preferably, d is 0.25 to 0.5 times R, and R is 0.5 to 5 mm; the plate is a stainless steel plate.

[0010] Preferably, the range of n is R+0.5d.

[0011] Preferably, the polymer is selected from polyvinyl alcohol, polyethylene oxide, and sodium polyacrylate, and the toughening agent is polyethylene glycol.

[0012] Preferably, based on the total mass of the polymer, water, and toughening agent, the content of polyvinyl alcohol is 10-15 wt%, the content of polyethylene oxide is 0.5-2 wt%, the content of sodium polyacrylate is 0.5-2 wt%, and the content of toughening agent is 2-5 wt%.

[0013] Preferably, the mixing process further includes water bath heating and stirring, wherein the water bath heating temperature is 90-95°C and the stirring speed is 200-800 rpm.

[0014] Preferably, the irradiation parameters for the first, second, third, and fourth irradiation crosslinking are the same, with an electron accelerator of 0.5–10 MeV and a radiation dose of 1–15 kGy.

[0015] This application also provides a mechanically interlocked topology structure, comprising a first cross-linked network, a second cross-linked network, a third cross-linked network, and a fourth cross-linked network. The first cross-linked network is obtained by irradiating a radiation-crosslinkable polymer and a toughening agent under a sheet material. The second cross-linked network is obtained by irradiating the first cross-linked network under a horizontal displacement *n*. The third cross-linked network is obtained by irradiating the second cross-linked network under a vertical displacement *n*. The fourth cross-linked network is obtained by irradiating the third cross-linked network under a horizontally opposite displacement *n*. The sheet material is a sheet material with a uniformly distributed through-hole structure, where *n* is... R is the radius of the circular through hole, and d is the distance between adjacent circular through holes.

[0016] Preferably, the hydrogel material has a topological structure with a fourfold cross-linking density, the topological structure including a physical cross-linking network and a chemical cross-linking network, wherein the physical cross-linking network is driven by intermolecular hydrogen bonds and the chemical cross-linking network is driven by covalent bonds of fourfold radiation cross-linking.

[0017] Preferably, the content of the first crosslinking network is 50-60%, the content of the second crosslinking network is 35-40%, the content of the third crosslinking network is 4-6%, and the content of the fourth crosslinking network is 1.5-2%.

[0018] This application provides a method for preparing a mechanically interlocked topological structure hydrogel. Using a radiation-crosslinkable polymer and a toughening agent as raw materials, and employing a specific radiation shielding device, the hydrogel material is obtained through radiation at different locations. In this method, the radiation shielding device can shield the electron beam, allowing it to crosslink the hydrogel only through through-holes. Each radiation crosslinking process ensures that only the hydrogel corresponding to the through-hole receives the electron beam and completes the crosslinking. Furthermore, by moving the radiation shielding device, different regions of the hydrogel are crosslinked, resulting in irradiated regions with different overlapping crosslinks. These regions are interconnected in a ring-like mechanical interlocking pattern, achieving topological crosslinking. The crosslinking dose and density of different overlapping parts in the topological structure are higher than in other regions, ultimately yielding hydrogel materials with four overlapping crosslinking densities. Therefore, when the hydrogel material prepared in this application is subjected to external force, the fourfold topological structure exhibits spring-like stretching and contraction, gradually dissipating the energy of the external force from one to fourfold crosslinking, thus improving the toughness and strength of the hydrogel. Attached Figure Description

[0019] Figure 1 A schematic diagram of the planar structure of the radiation shielding device provided by the present invention;

[0020] Figure 2 This is a schematic diagram of the structural state of the mechanically interlocked topological hydrogel material provided by the present invention; wherein 1 represents single crosslinking, 2 represents double crosslinking, 3 represents triple crosslinking, and 4 represents quadruple crosslinking.

[0021] Figure 3 A diagram illustrating the optimal distribution of the quadruple crosslinking topology provided by this invention, where n = R + 0.5d. Detailed Implementation

[0022] To further understand the present invention, preferred embodiments of the present invention are described below in conjunction with examples. However, it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, and not for limiting the scope of the claims of the present invention.

[0023] In view of the performance requirements for strength and toughness of existing hydrogel materials, this application provides a mechanically interlocked topological structure hydrogel material and its preparation method. This invention uses a radiation method combined with a specific radiation shielding device and movement mode to prepare a mechanically interlocked topological structure hydrogel, improving the strength and toughness of the hydrogel and giving it high biocompatibility, high strength, and high toughness, meeting its application requirements in the field of medical materials. Specifically, this invention discloses a method for preparing a mechanically interlocked topological structure hydrogel material, including the following steps:

[0024] A) A radiation-crosslinkable polymer, water, and a toughening agent are mixed to obtain a hydrogel prepolymer;

[0025] B) Cover the upper surface of the hydrogel prepolymer with a radiation shielding device to obtain an object to be irradiated; the radiation shielding device is a plate with a uniformly distributed circular through-hole structure.

[0026] C) The sample to be irradiated is placed in the electron accelerator track, and the electron accelerator is turned on for the first radiation crosslinking. The sample is then moved horizontally by a displacement *n* for the second radiation crosslinking, followed by a third radiation crosslinking by moving the sample vertically by a displacement *n*, and finally a fourth radiation crosslinking by moving the sample horizontally in the opposite direction by a displacement *n*, resulting in a mechanically interlocked topological structure hydrogel material, where *n* is... R is the radius of the circular through hole, and d is the distance between adjacent circular through holes.

[0027] In the preparation process of mechanically interlocked topological hydrogel materials, this application first mixes a radiation-crosslinkable polymer, water, and a toughening agent to obtain a hydrogel prepolymer. During this process, the radiation-crosslinkable polymer can be a water-soluble polymer capable of radiation crosslinking. In this application, the polymer is specifically selected from polyvinyl alcohol, polyethylene oxide, and sodium polyacrylate, which together serve as the radiation crosslinking backbone. The toughening agent is polyethylene glycol. The terminal OH groups of polyethylene glycol form hydrogen bonds with the side OH groups on the polyvinyl alcohol molecular chain. As the ratio of the two approaches, the hydrogen bonding effect is enhanced, generating a physical crosslinking network and improving the strength of the hydrogel. Based on the total mass of the polymer, water, and toughening agent, the content of polyvinyl alcohol is 10-15 wt%, the content of polyethylene oxide is 0.5-2 wt%, the content of sodium polyacrylate is 0.5-2 wt%, and the content of toughening agent is 2-5 wt%. Specifically, the content of polyvinyl alcohol is 12-14 wt%, the content of polyethylene oxide is 1-1.5 wt%, the content of sodium polyacrylate is 1-1.5 wt%, and the content of toughening agent is 2.5-4 wt%. The mass ratio of polyvinyl alcohol to toughening agent is 4:1 to 3:1. To ensure sufficient crosslinking, the mixing process includes water bath heating and stirring at a temperature of 90-95°C and a stirring speed of 200-800 rpm.

[0028] According to the present invention, a radiation shielding device is then covered on the upper surface of the hydrogel prepolymer to obtain an object to be irradiated. The radiation shielding device is a plate with a uniformly distributed through-hole structure. The radiation shielding device described in this application needs to be able to partially shield electron beam radiation, that is, the through-hole structure does not partially shield electron beam radiation, in order to achieve radiation crosslinking of the hydrogel. In a specific embodiment, the through-hole structure is a circular hole with a radius of R, the spacing d of the circular holes is 0.25 to 0.5 times R, and R is 0.5 to 5 mm; the plate is a stainless steel plate; the specific details of this radiation shielding device are as follows: Figure 1 As shown.

[0029] This application then places the aforementioned material to be irradiated in an electron accelerator track and activates the electron accelerator for the first radiation crosslinking. A second radiation crosslinking is then performed by moving the material a displacement *n* in the horizontal direction, followed by a third radiation crosslinking by moving the material a displacement *n* in the vertical direction. Finally, a fourth radiation crosslinking is performed by moving the material a displacement *n* in the opposite horizontal direction, resulting in a mechanically interlocked topological structure hydrogel material, where *n* is... R is the radius of the circular through-hole. In the above-mentioned electron accelerator irradiation crosslinking, the non-through-hole area of ​​the radiation shielding device can shield the electron beam, and the electron beam performs irradiation crosslinking on the hydrogel through the through-hole. By moving the radiation shielding device before the second, third, and fourth irradiation crosslinking, crosslinking occurs in different through-hole areas during subsequent electron beam irradiation, resulting in irradiated areas with different overlapping crosslinks. In this application, the movement of the plate before the second, third, and fourth irradiation crosslinkings all begin from the position where the plate was after the previous irradiation crosslinking, without any repositioning of the plate in between.

[0030] Based on the use of the aforementioned stainless steel plate with uniformly distributed circular holes in the radiation shielding device, the range of n is: The optimal value is R+0.5d. A schematic diagram of the topological structure of the hydrogel material prepared in this application is shown below. Figure 2 As shown, it can be seen that moving a distance n can lead to changes in the topology, especially when n has an extreme value of n. At that time, the radiation region of the third translation is tangent to the upper left part of the circular aperture of the first radiation region; when n is at its extreme value... When the radiation region of the third translation is tangent to the lower right part of the circular hole of the first radiation region, the area of ​​the three overlapping regions will decrease when they are tangent. When the optimal value of n is R+0.5d, the topological structure is a highly symmetrical structure with the four overlapping regions evenly distributed, and theoretically the stretching properties of the gel are optimal.

[0031] In a specific embodiment, n is the displacement of R + 0.5d, and the optimally distributed quadruple cross-linked topology is shown. Figure 3 Building upon this, by using a mobile radiation shielding device, different regions of the hydrogel were cross-linked to obtain irradiated regions with varying degrees of overlap: single-overlap, double-overlap, triple-overlap, and quadruple-overlap regions. These four types of overlap regions are interconnected in a ring-like mechanical interlocking pattern, achieving topological cross-linking. As the number of overlaps increases, the overlap regions also move from the edges to the center. The cross-linking dose and density of the multi-overlapping parts are higher than those of the low-overlapping parts. These overlapping regions ultimately link together to form a petal-like topological hydrogel with four different overlap cross-linking densities. Therefore, when the hydrogel is subjected to external forces, the multiple topological structures exhibit spring-like stretching and contraction, progressively dissipating the energy of the external force from single-overlap to quadruple-overlap, thus improving the hydrogel's toughness and strength.

[0032] In the above-mentioned radiation crosslinking process, the radiation parameters are the same each time, the electron accelerator is 0.5 to 10 MeV, and the radiation dose is 1 to 15 kGy each time; specifically, the electron accelerator is 2 to 8 MeV, and the radiation dose is 3 to 12 kGy each time.

[0033] Furthermore, this application also provides a mechanically interlocked topological hydrogel material, composed of a first crosslinking network, a second crosslinking network, a third crosslinking network, and a fourth crosslinking network. The first crosslinking network is obtained by irradiation of a radiation-crosslinkable polymer and a toughening agent under a substrate. The second crosslinking network is obtained by irradiating the first crosslinking network under a horizontal displacement of n. The third crosslinking network is obtained by irradiating the second crosslinking network under a vertical displacement of n. The fourth crosslinking network is obtained by irradiating the third crosslinking network under a horizontal displacement of n in the opposite direction. The substrate is a substrate with a uniformly distributed through-pore structure, where n is... R is the radius of the circular through hole.

[0034] In the mechanically interlocked topological hydrogel material of this application, the hydrogel material has a fourfold cross-linking density topological structure, which includes a physical cross-linking network and a chemical cross-linking network. The physical cross-linking network is driven by intermolecular hydrogen bonds, and the chemical cross-linking network is driven by covalent bonds formed by fourfold radiation cross-linking. More specifically, the content of the first cross-linking network is 50-60%, the content of the second cross-linking network is 35-40%, the content of the third cross-linking network is 4-6%, and the content of the fourth cross-linking network is 1.5-2%.

[0035] This invention provides a method for preparing a mechanically interlocked topological hydrogel. The method involves multiple translational cross-regional radiation cross-linking through a radiation shielding device to obtain irradiated regions with different overlapping cross-links. Each region is interconnected in a ring-like mechanical interlocking pattern, resulting in a topological hydrogel material with four overlapping cross-linking densities that have a petal-like shape (when the radiation shielding device is a circular through-hole). When subjected to external force, the topological structure exhibits spring-like stretching and contraction, gradually dissipating the energy of the external force from one to four layers of cross-linking, thereby improving the toughness of the hydrogel and obtaining a high-toughness mechanically interlocked topological hydrogel material.

[0036] Furthermore, this invention utilizes the intermolecular hydrogen bonds of polyvinyl alcohol and polyethylene glycol as a physical crosslinking network and the covalent bonds of quadruple radiation crosslinking as a chemical crosslinking network to prepare an interpenetrating structure with dual-network and multiple bonding, thereby improving the strength of the hydrogel. Additionally, the topology of the hydrogel can be controlled by adjusting the radiation dose and the radius R and inter-pore distance d of the radiation shielding device, thus achieving precise control over the strength and toughness of the hydrogel.

[0037] This invention uses a radiation method to prepare a high-toughness mechanically interlocked topological structure hydrogel. The production process does not require the introduction of small molecule monomers or initiators, and it has good biocompatibility, making it very suitable for the preparation of medical high-toughness hydrogel materials.

[0038] To further understand the present invention, the mechanically interlocked topological structure hydrogel material and its preparation method provided by the present invention will be described in detail below with reference to the embodiments. The scope of protection of the present invention is not limited by the following embodiments.

[0039] Example 1

[0040] According to the raw material composition ratio in Table 1 below, weigh out a fixed amount of polyvinyl alcohol, polyethylene oxide, sodium polyacrylate, polyethylene glycol, and water. Dissolve them into a homogeneous and transparent solution by heating and stirring in a water bath at 95℃ to obtain a hydrogel prepolymer. Dispense the prepolymer into tray molds with dimensions of 20cm × 20cm × 0.3cm. The selected radiation-specific device is a perforated stainless steel plate with a diameter of 20cm × 20cm and a hole spacing d of 1mm. It is placed above the tray mold; the electron accelerator is placed in the running track, and the electron accelerator is turned on for radiation crosslinking. A total of 4 radiation crosslinkings are required. The radiation parameters for each radiation are: electron beam energy of 2MeV, radiation dose of 5kGy, and total dose of 20kGy. After the first radiation crosslinking is completed, the stainless steel plate is moved horizontally by a displacement of R+0.5d=3mm for 1 radiation crosslinking. Then, the stainless steel plate is moved vertically by a displacement of 3mm for 1 radiation crosslinking. Finally, it is moved horizontally in the opposite direction by a displacement of 3mm for 1 radiation crosslinking, thus obtaining the hydrogel material.

[0041] Table 1. Raw material composition table for Example 1

[0042]

[0043] The prepared hydrogel was tested for tensile properties and cytotoxicity. The specific test methods and results are as follows:

[0044] The tensile properties were tested as follows: a single-column benchtop computer-controlled peel tester (CREE-8007B) was used to perform tensile tests on the samples. The tensile rate was 200 mm / min, and the test temperature was room temperature. The sample was dumbbell-shaped with a total length of 75 mm, an end width of 12.5 mm, a narrow parallel section length of 33 mm, and a narrow parallel section width of 4 mm. Three sets of parallel samples were tested, and the average tensile strength and elongation at fracture were calculated. The toughness was calculated using stress-strain curve theory.

[0045] Cytotoxicity test: conducted in accordance with GB / T 16886.5-2003 Biological evaluation of medical devices - Part 5: In vitro cytotoxicity test;

[0046] Table 2 Tensile properties and cytotoxicity test results of Example 1

[0047]

[0048]

[0049] The test results show that in experiments 1 to 6, the elongation of the hydrogel exceeded 500%, and the toughness was greater than 600 kJ / m. 3 This indicates that the hydrogel material has good toughness, and the 0-level cytotoxicity also indicates that the hydrogel has good biocompatibility.

[0050] The test results of the control group in Experiments 7 and 8, compared with those in Experiment 6, show that the elongation, strength and toughness of the hydrogel all decreased significantly when the raw material composition was changed.

[0051] Comparative Example 1

[0052] The raw material composition and dissolution method of the hydrogel prepolymer were the same as those in Experiment 6 of Example 1. The hydrogel prepolymer was packaged into a 20cm×20cm×0.3cm tray mold and placed in the running track of the electron accelerator, but without using a radiation-specific auxiliary device. The radiation parameters were the same as those in Experiment 6, with an electron beam energy of 2MeV, a radiation dose of 5kGy per irradiation, and a total of 4 irradiations for a total dose of 20kGy. The tensile properties and cytotoxicity of the prepared hydrogel were tested, and the test results are shown in Table 3.

[0053] Table 3. Tensile properties and cytotoxicity tests in Experiment 6 of Comparative Example 1 and Example 1.

[0054]

[0055] Test results show that, without the use of radiation-specific auxiliary devices, the elongation, tensile strength, and toughness of the hydrogel are significantly reduced under the same formulation and cumulative dose.

[0056] Example 2

[0057] The effect of different aperture sizes on the toughness of the hydrogel was tested by adjusting the radiation-specific device.

[0058] The dissolution method and ratio of the hydrogel prepolymer were the same as in Experiment 6 of Example 1. The hydrogel prepolymer was dispensed into a 20cm×20cm×0.3cm tray mold. Different specifications of radiation crosslinking auxiliary devices with an area of ​​20cm×20cm were selected. The specific parameters are shown in Table 4. The device was placed on top of the tray mold and placed together in the running track of the electron accelerator for radiation crosslinking. The radiation parameters were an electron beam energy of 2MeV and a radiation dose of 5kGy per radiation. After the first radiation crosslinking was completed, the stainless steel plate was moved by n displacements in the horizontal direction for one radiation crosslinking. Then, the stainless steel plate was moved by n displacements in the vertical direction for one radiation crosslinking. Finally, it was moved by n displacements in the opposite horizontal direction for one radiation crosslinking, resulting in a high-toughness hydrogel material. The tensile properties and cytotoxicity of the hydrogel were tested, and the test results are shown in Table 5.

[0059] Table 4. Parameter table of the radiation-specific device in Example 2

[0060] raw material Experiment 6 Experiment 9 Experiment 10 Experiment 11 Hole radius R / mm 2.5 2.5 5 5 Hole spacing d / mm 1 0.625 1.25 2.5 Translation dimension n / mm 3 2.8125 5.625 6.25

[0061] Table 5. Tensile properties and cytotoxicity test results of Example 2

[0062]

[0063] Table 5 shows that, through comparison of tensile test data, it is evident that the smaller the radius of the circular holes and the smaller the spacing between them, the more compact the topological structure of the hydrogel, resulting in greater elongation, tensile strength, and toughness. (Comparative Example 2)

[0064] The effect of adjusting the translation distance n of the radiation-specific device during the preparation process on the toughness of the hydrogel was tested.

[0065] The dissolution method and ratio of the hydrogel prepolymer were the same as in Experiment 6 of Example 1. The hydrogel prepolymer was dispensed into a 20cm×20cm×0.3cm tray mold. Different specifications of radiation crosslinking auxiliary devices with an area of ​​20cm×20cm were selected. The specific parameters are shown in Table 6. The device was placed on top of the tray mold and placed together in the running track of the electron accelerator for radiation crosslinking. The radiation parameters were an electron beam energy of 2MeV and a radiation dose of 5kGy per radiation. After the first radiation crosslinking was completed, the stainless steel plate was moved by n displacements in the horizontal direction for one radiation crosslinking. Then, the stainless steel plate was moved by n displacements in the vertical direction for one radiation crosslinking. Finally, it was moved by n displacements in the opposite horizontal direction for one radiation crosslinking, resulting in a high-toughness hydrogel material. The tensile properties and cytotoxicity of the hydrogel were tested, and the test results are shown in Table 7.

[0066] Table 6. Parameter table of the radiation-specific device in Comparative Example 2

[0067] raw material Experiment 6 Experiment 12 Experiment 13 Experiment 14 Experiment 15 Hole radius R / mm 2.5 2.5 2.5 2.5 2.5 Hole spacing d / mm 1 1 1 1 1 Translation dimension n / mm 3 2.465 3.535 2 4

[0068] Table 7 Comparative Test Results of Tensile Properties and Cytotoxicity of Example 2

[0069]

[0070] As shown in Table 7, the moving distance n is within the set range At the limit, i.e. Experiments 12 and 13, the strength and toughness are significantly reduced compared to Experiment 6; the moving distance n is not within the set range, and leakage points appear in the gel crosslinking, which cannot be completely crosslinked and formed.

[0071] Example 3: Adjusting radiation parameters and testing their effect on hydrogel toughness.

[0072] The dissolution method and proportion of the hydrogel prepolymer were the same as in Experiment 6 of Example 1. The hydrogel prepolymer was dispensed into a 20cm×20cm×0.3cm tray mold. The selected radiation device was a perforated stainless steel plate with a circular hole radius of 2.5mm and an area of ​​20cm×20cm. The spacing d between the circular holes was 1mm. The plate was placed on top of the tray mold and then placed together in the running track of the electron accelerator for radiation crosslinking. The radiation details are shown in Table 8. After the first radiation crosslinking, the stainless steel plate was moved by a radius along the horizontal direction for one radiation crosslinking. Then, the stainless steel plate was moved by a radius along the vertical direction for one radiation crosslinking. Finally, the radius was moved in the opposite horizontal direction for one radiation crosslinking, resulting in a high-toughness hydrogel material. The tensile properties and cytotoxicity of the hydrogel were tested, and the test results are shown in Table 9 below.

[0073] Table 8 Radiation Parameters of Example 3

[0074] Radiation parameters Experiment 6 Experiment 16 Experiment 17 Experiment 18 Electron beam energy (MeV) 2 2 5 5 Single radiation dose (kGy) 5 10 5 10

[0075] Table 9 Tensile properties and cytotoxicity test results of Example 3

[0076]

[0077] As shown in Table 9, the comparison of tensile test data indicates that the elongation, tensile strength and toughness of the hydrogel increase with increasing radiation dose; the toughness of the hydrogel also increases with increasing electron beam energy.

[0078] The above description of the embodiments is only for the purpose of helping to understand the method and core ideas of the present invention. It should be noted that those skilled in the art can make several improvements and modifications to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

[0079] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for preparing a mechanically interlocked topological structure hydrogel material, comprising the following steps: A) A radiation-crosslinkable polymer, water, and a toughening agent are mixed to obtain a hydrogel prepolymer; the polymer is selected from polyvinyl alcohol, polyethylene oxide, and sodium polyacrylate, and the toughening agent is polyethylene glycol; based on the total mass of the polymer, water, and toughening agent, the content of polyvinyl alcohol is 10-15 wt%, the content of polyethylene oxide is 0.5-2 wt%, the content of sodium polyacrylate is 0.5-2 wt%, and the content of toughening agent is 2-5 wt%. B) Cover the upper surface of the hydrogel prepolymer with a radiation shielding device to obtain an object to be irradiated; the radiation shielding device is a plate with a uniformly distributed circular through-hole structure; C) The object to be irradiated is placed in the electron accelerator track, and the electron accelerator is turned on to perform the first radiation crosslinking. The plate is then moved horizontally by a displacement *n* for the second radiation crosslinking, followed by a third radiation crosslinking along the vertical direction by a displacement *n*, and finally a fourth radiation crosslinking along the opposite horizontal direction by a displacement *n*, resulting in a mechanically interlocked topology. The value of *n* ranges from (2-...). R+d~ R, where d is 0.25 to 0.5 times R, R is the radius of the circular through hole, and d is the spacing between adjacent circular through holes.

2. The preparation method according to claim 1, characterized in that, The radius R is 0.5~5mm; the plate material is stainless steel.

3. The preparation method according to claim 2, characterized in that, The range of n is R+0.5d.

4. The preparation method according to claim 1, characterized in that, The mixing process includes water bath heating and stirring, wherein the water bath temperature is 90~95℃ and the stirring speed is 200~800rpm.

5. The preparation method according to claim 1, characterized in that, The irradiation parameters for the first, second, third, and fourth irradiation crosslinking processes are the same: the electron accelerator is 0.5~10MeV, and the radiation dose is 1~15kGy.

6. A mechanically interlocked topological structure, comprising a first crosslinked network, a second crosslinked network, a third crosslinked network, and a fourth crosslinked network, wherein the first crosslinked network is obtained by irradiation of a hydrogel prepolymer obtained from a radiation-crosslinkable polymer, water, and a toughening agent under a sheet material; the second crosslinked network is obtained by irradiation of the first crosslinked network under a horizontal displacement n of the sheet material; the third crosslinked network is obtained by irradiation of the second crosslinked network under a vertical displacement n of the sheet material; and the fourth crosslinked network is obtained by irradiation of the third crosslinked network under a horizontally opposite displacement n of the sheet material; the sheet material is a sheet material with a uniformly distributed through-hole structure, wherein n is (2- R+d~ R, where d is 0.25 to 0.5 times R, R is the radius of the circular through hole, and d is the spacing between adjacent circular through holes; The polymer is selected from polyvinyl alcohol, polyethylene oxide, and sodium polyacrylate, and the toughening agent is polyethylene glycol. Based on the total mass of the polymer, water, and toughening agent, the content of polyvinyl alcohol is 10-15 wt%, the content of polyethylene oxide is 0.5-2 wt%, the content of sodium polyacrylate is 0.5-2 wt%, and the content of toughening agent is 2-5 wt%.

7. The mechanically interlocked topology according to claim 6, characterized in that, The hydrogel material has a topological structure with a fourfold cross-linking density, which includes a physical cross-linking network and a chemical cross-linking network. The physical cross-linking network is driven by intermolecular hydrogen bonds, and the chemical cross-linking network is driven by covalent bonds of fourfold radiation cross-linking.

8. The mechanically interlocked topology according to claim 6, characterized in that, The content of the first crosslinking network is 50-60%, the content of the second crosslinking network is 35-40%, the content of the third crosslinking network is 4-6%, and the content of the fourth crosslinking network is 1.5-2%.

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