Artificial ligament and method for its production

Abstract

The present application relates to the field of medical materials, in particular to an artificial ligament and a preparation method thereof.The artificial ligament provided by the present application comprises a gel layer-artificial ligament composite system by preparing a layer of PVA hydrogel on the surface of the woven artificial ligament in situ, which has biological activity and anti-creep performance, and is beneficial to improve the medium and long-term clinical prognosis of the woven artificial ligament.The artificial ligament provided by the present application can also adjust the rigidity, thickness and micro-topology of the gel layer under cyclic loading, thereby producing different biological activity regulation effects, and there is a balance point of rigidity and micro-topology, so that the cell ingrowth induction effect is best.The artificial ligament provided by the present application has simple composition, only relies on biophysical clues to regulate cell behavior, avoids the biological safety problems caused by complex biological chemical components, and can simultaneously realize the biological activity improvement and anti-creep performance improvement of the traditional PET woven artificial ligament.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of medical materials, in particular to an artificial ligament and a preparation method thereof. BACKGROUND

[0002] The braided artificial ligament refers to a braided body prepared by knitting or weaving, and the material is mostly PET. Artificial ligaments have become an important choice for clinical reconstruction of knee joint function. At present, polyethylene terephthalate (PET) braided artificial ligaments such as LARS are widely used in clinical practice in China. PET braided artificial ligaments have reliable mechanical properties, excellent biocompatibility, and can achieve knee joint function reconstruction within one month.

[0003] However, long-term follow-up indicates that PET braided artificial ligaments have a considerable complication rate (severe synovitis, bone tunnel expansion, etc.). The main causes of complications of PET braided artificial ligaments are as follows: (1) PET is a hydrophobic material and lacks biological activity, so it is difficult to form bone union with the host tissue and cause wear at the bone tunnel interface, resulting in bone tunnel expansion or wear debris; (2) the anti-creep performance of the PET braided body is limited, and stress relaxation easily occurs under medium and long-term use, resulting in a decrease in the restraining effect. In short, the lack of biological activity of PET material and the insufficient anti-creep performance of the braided body lead to serious complications in the medium and long-term prognosis of PET braided artificial ligaments. Related researchers have proposed some artificial ligament preparation methods to address the aforementioned shortcomings, but there are few reports on preparation strategies that can simultaneously improve biological activity and anti-creep performance.

[0004] The prior art discloses a number of hydrogel materials that can be used as medical materials. The use of hydrogel materials may be able to solve the above problems. The hydrogel materials that are currently widely studied include PVA hydrogel. However, on the one hand, there is no report on whether such a gel can form a coating on the surface of a PET substrate, and on the other hand, the PVA hydrogel that has completed the gelation transformation does not have adhesion, so theoretically, conventional PVA hydrogel cannot directly adhere to the PET substrate to form a coating.

[0005] In addition, although PVA hydrogel has excellent biocompatibility as a tissue engineering scaffold, its tissue induction is often limited. In short, even if there is a way to directly adhere PVA hydrogel to the PET substrate to form a coating, it is impossible to achieve high induction. SUMMARY

[0006] Therefore, the technical problem to be solved by the present application is to provide an artificial ligament and a preparation method thereof. The artificial ligament provided by the present application has high biological activity and anti-creep performance.

[0007] The application provides an artificial ligament, comprising:

[0008] a woven body;

[0009] a polyvinyl alcohol (PVA) hydrogel arranged on the woven body;

[0010] The PVA hydrogel is obtained by removing dimethyl sulfoxide (DMSO) from a precursor solution of DMSO, PVA and water after gelation; in the precursor solution of DMSO, PVA and water, the content of PVA is 5 w / v% to 15 w / v%, and the volume ratio of DMSO to water is (8:2) to (2:8).

[0011] The artificial ligament provided by the application comprises a woven body; the application does not have specific requirements for the weaving method of the woven body. In some embodiments of the application, the woven body is a woven structure obtained by weaving. The base material of the woven body in the application is selected from one or more of polyethylene terephthalate (PET) fibers, polycaprolactone (PCL) fibers, aramid fibers, polyether-ether-ketone (PEEK) fibers, carbon fibers or silk.

[0012] The artificial ligament provided by the application further comprises a PVA hydrogel arranged on the woven body; the PVA hydrogel is obtained by removing DMSO from a precursor solution of DMSO, PVA and water after gelation; in the precursor solution of DMSO, PVA and water, the content of PVA is 5 w / v% to 15 w / v%, and the volume ratio of DMSO to water is (8:2) to (2:8).

[0013] The inventors of the present application creatively found that DMSO-H2O-PVA can be transformed by gelation to form a stable and adherent biomedical gel layer on the surface of the woven body. On the one hand, DMSO can fully infiltrate the hydrophobic surface of PET, so that PVA fully dissolved in DMSO can fully contact with PET, thereby forming hydrogen bond connection between the PVA molecular chain and the benzene ring and carbonyl group on the PET molecular chain. On the other hand, in order to ensure the biocompatibility of the gel layer, DMSO should be fully eluted with pure water after the gelation transformation is completed, which will lead to further increase, expansion and aggregation of the PVA crystal region, and further fix the gel layer. In addition, considering the complex structure of the woven body, mechanical interlocking will be formed between the PVA gel layer and the PET woven body, which further ensures the tightness of the combination of the gel layer and the woven body.

[0014] Preferably, the content of PVA in the precursor solution of DMSO, PVA and water of the present application is 5 w / v%~15 w / v%, and the volume ratio of DMSO to water is (8:2)~(3:7). More preferably, the content of PVA in the precursor solution of DMSO, PVA and water of the present application is 8 w / v%~12 w / v%, and the volume ratio of DMSO to water is (8:2)~(6:4). More preferably, the content of PVA in the precursor solution of DMSO, PVA and water of the present application is 9 w / v%~11 w / v%, and the volume ratio of DMSO to water is (7.5:2.5)~(6.5:3.5).

[0015] In the artificial ligament provided by the present application, the PVA hydrogel is subjected to cyclic deformation or not, preferably 5000~50000 times of cyclic deformation, more preferably 25000~50000 times of cyclic deformation; the deformation includes one or more of stretching, bending and twisting. The constraint ability of the PVA hydrogel of the present application to the macroscopic deformation of the composite system increases with the number of cyclic deformations, which is conducive to the promotion of cell adhesion and tissue ingrowth by the gel layer.

[0016] The present application also provides a preparation method of the artificial ligament, comprising the following steps:

[0017] S1) immersing the braided body in a precursor solution of DMSO, PVA and water, and then performing gelation transformation; the content of PVA in the precursor solution of DMSO, PVA and water is 5 w / v%~15 w / v%, and the volume ratio of DMSO to water is (8:2)~(2:8);

[0018] S2) after eluting DMSO from the material obtained in step S1), freeze-drying to obtain the artificial ligament.

[0019] The present application first immerses the braided body in a precursor solution of DMSO, PVA and water, and then performs gelation transformation. Specifically, the present application immerses the braided body in a precursor solution of DMSO, PVA and water, and then places the precursor solution with the immersed braided body in a low-temperature environment for gelation transformation; the temperature of the low-temperature environment is lower than 0℃, preferably above-40℃ and lower than 0℃, more preferably above-30℃ and lower than 0℃, and more preferably above-20℃ and lower than 0℃; the gelation transformation time is 8 h~14 h. It should be noted that too low temperature such as-80℃ may cause the gel precursor solution to freeze, so that the gelation process is closer to the traditional freeze-thaw cycle method rather than the microphase separation method of PVA-DMSO-water ternary blend liquid DMSO and water combined with PVA rejection. The braided body of the present application is the same as described above, and will not be repeated. The precursor solution of DMSO, PVA and water of the present application is the same as described above, and will not be repeated.

[0020] The artificial ligament is obtained by impregnating the braided body in a precursor solution of DMSO, PVA and water, then performing a gelation transition, eluting DMSO from the material obtained in step S1, and then performing freeze-drying. Specifically, the artificial ligament is obtained by performing freeze-drying, and then performing rehydration. The freeze-drying is performed at a temperature of -80℃ or lower for 20-25 hours. The rehydration is performed in physiological saline until the artificial ligament is fully swollen.

[0021] The artificial ligament is obtained by impregnating the braided body in a precursor solution of DMSO, PVA and water, then performing a gelation transition, eluting DMSO from the material obtained in step S1, and then performing freeze-drying. Specifically, the artificial ligament is obtained by performing freeze-drying, and then performing rehydration. The freeze-drying is performed at a temperature of -80℃ or lower for 20-25 hours. The rehydration is performed in physiological saline until the artificial ligament is fully swollen.

[0022] The artificial ligament is obtained by impregnating the braided body in a precursor solution of DMSO, PVA and water, then performing a gelation transition, eluting DMSO from the material obtained in step S1, and then performing freeze-drying. Specifically, the artificial ligament is obtained by performing freeze-drying, and then performing rehydration. The freeze-drying is performed at a temperature of -80℃ or lower for 20-25 hours. The rehydration is performed in physiological saline until the artificial ligament is fully swollen.

[0023] The artificial ligament is obtained by impregnating the braided body in a precursor solution of DMSO, PVA and water, then performing a gelation transition, eluting DMSO from the material obtained in step S1, and then performing freeze-drying. Specifically, the artificial ligament is obtained by performing freeze-drying, and then performing rehydration. The freeze-drying is performed at a temperature of -80℃ or lower for 20-25 hours. The rehydration is performed in physiological saline until the artificial ligament is fully swollen.

[0024] The application discloses an artificial ligament and a preparation method thereof. The artificial ligament provided by the application is a "gel layer-artificial ligament" composite system composed of a PVA hydrogel prepared in situ on the surface of a woven artificial ligament, and the system has biological activity and anti-creep performance, and is beneficial to improving the medium and long-term clinical prognosis of the woven artificial ligament. The artificial ligament provided by the application can also adjust the rigidity, thickness and micro-topology of the gel layer under cyclic loading, thereby producing different biological activity regulation effects, and there is a balance point of rigidity and micro-topology, so that the cell ingrowth induction effect is best. Compared with other competitors, the artificial ligament provided by the application has simple components, and only relies on biophysical clues (porosity, surface rigidity and other material properties) to regulate cell behavior, avoids biological safety problems caused by complex biological chemical components, and can simultaneously realize the biological activity improvement and anti-creep performance improvement of the traditional PET woven artificial ligament. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 A preparation flowchart of the PET artificial ligament described in the application;

[0026] Figure 2 A scanning electron microscope image of the finished product of Examples 1, 3 and 5;

[0027] Figure 3 A scanning electron microscope image of the finished product of Examples 2, 4 and 6;

[0028] Figure 4 A scanning electron microscope image of the finished product of Examples 1-6 of the application;

[0029] Figure 5 A tensile load change of the finished product obtained by stretching of Examples 2, 4 and 6 and a fiber morphology diagram after dehydration and drying;

[0030] Figure 6 A recess depth result diagram of the finished product of Examples 1-6 after surface rigidity testing;

[0031] Figure 7 A mean surface rigidity result diagram of the finished product of Examples 1-6;

[0032] Figure 8 A surface rigidity distribution diagram of the finished product of Examples 1-6;

[0033] Figure 9 A scanning electron microscope image of the finished product of Examples 1-6 after cell adhesion;

[0034] Figure 10 A light microscope image of the finished product of Examples 1-6 after cell adhesion;

[0035] Figure 11 The graph shows the quantitative statistical results of cell adhesion of the finished products obtained in Examples 1-6. Detailed Implementation

[0036] This invention discloses an artificial ligament and its preparation method. Those skilled in the art can refer to the content of this document and appropriately modify the process parameters to achieve the desired result. It should be particularly noted that all similar substitutions and modifications are obvious to those skilled in the art and are considered to be included in this invention. The method and application of this invention have been described through preferred embodiments, and those skilled in the art can obviously make modifications or appropriate alterations and combinations to the method and application described herein without departing from the content, spirit, and scope of this invention to realize and apply the technology of this invention.

[0037] like Figure 1 As shown, Figure 1 This is a flowchart illustrating the preparation process of the PET artificial ligament described in this invention. Figure 1 As can be seen, this invention mixes PVA, DMSO, and water and heats them to obtain a precursor solution; then, a PET artificial ligament is placed into the precursor solution and stored together at low temperature to complete the gelation transformation and obtain a PVA solvent displacement gel-PET artificial ligament composite system; then, DMSO is eluted to obtain a PVA hydrogel-PET artificial ligament composite system; finally, after freeze-drying and rehydration, the gel layer is acclimatized by cyclic axial load to eliminate the initial stress relaxation of the system and obtain the finished product.

[0038] The present invention will be further described below with reference to the embodiments:

[0039] Example 1

[0040] 1. Preparation of precursor solution: DMSO, PVA, and water are mixed in a certain proportion and heated in an oil bath at 95°C with stirring to obtain a clear and transparent precursor solution. The PVA content is 10 w / v, and the volume ratio of DMSO to water is 7:3.

[0041] 2. Assembly of PET artificial ligament and precursor solution: The PET artificial ligament is fully immersed in the precursor solution, and vacuum degassing is performed to ensure full contact between the precursor solution and the PET matrix. The PET artificial ligament is a texture obtained by weaving PET fibers.

[0042] 3. Gelation transformation: Using a hollow plastic tube that matches the artificial ligament braid as a mold, the artificial ligament braid is held in the center of the hollow plastic tube. After injecting the precursor liquid, the mold, braid, and precursor liquid are placed together in a low-temperature environment (below zero degrees Celsius) and kept there for 12 hours to complete the gelation transformation and obtain the PVA solvent displacement gel-PET artificial ligament composite system.

[0043] 4. Elution of DMSO: The PVA solvent-substituted gel-PET artificial ligament composite system is immersed in pure water to elute DMSO by mechanical stirring and the like, and the water is changed several times during the elution. After sufficient washing, the PVA solvent-substituted gel is converted into a PVA hydrogel, and a PVA hydrogel-PET artificial ligament composite system is obtained.

[0044] 5. Post-processing: The PVA hydrogel-PET artificial ligament composite system in step 4 is freeze-dried and rehydrated. Specifically, the PVA hydrogel-PET artificial ligament composite system after sufficient washing is first pre-frozen in a -80°C refrigerator for 6 h, and then freeze-dried in a freeze dryer with a cold trap temperature of -80°C for 24 h. Then, the PVA hydrogel-PET artificial ligament composite system after freeze-drying is immersed in 0.01M phosphate buffer saline (PBS) (pH = 7) for 24 h, and is considered to be fully swollen. The overall freeze-drying and rehydration strengthen the crystal region connection in the PVA hydrogel, and a gel layer with more reliable mechanical properties is obtained, and the final product is obtained (labeled as "not stretched").

[0045] Example 2

[0046] The unstretched final product is obtained according to the method of Example 1, and then the gel layer macromolecular network is domesticated and the initial stress relaxation of the composite system is eliminated by cyclic stretching of the axial load for 30000 times (the load is applied by a biomechanical dynamic fatigue tester, the load is output by a motor, the load waveform is a sine waveform, the peak is 100 N, the valley is 50 N, and the loading frequency is 2 Hz.) to obtain the final product with macroscopic mechanical properties matching the host bone tissue and micro-topological structure suitable for cell growth (labeled as "stretched").

[0047] Example 3

[0048] 1. Preparation of precursor solution: DMSO, PVA and water are mixed in a certain proportion, and a clear and transparent precursor solution is obtained by stirring in an oil bath at 95°C. The PVA content is 10 w / v %, and the volume ratio of DMSO and water is 5:5.

[0049] 2. Assembly of PET artificial ligament and precursor solution: The PET artificial ligament is fully immersed in the precursor solution, and vacuum degassing is performed to ensure sufficient contact between the precursor solution and the PET matrix. The PET artificial ligament is a woven structure obtained by weaving PET fibers.

[0050] 3. Gelation transition: Hollow plastic tube matched with artificial ligament braided body as mold, artificial ligament braided body maintained in the center of hollow plastic tube, after pouring precursor solution, together with mold, braided body, precursor solution placed in low temperature environment (below zero degree) to keep, after 12h, gelation transition completed, PVA solvent replacement gel-PET artificial ligament composite system obtained.

[0051] 4. Elution of DMSO: PVA solvent replacement gel-PET artificial ligament composite system immersed in pure water, elution of DMSO by mechanical stirring and other methods, multiple water changes during the process. After sufficient washing, PVA solvent replacement gel is converted to PVA hydrogel, obtaining PVA hydrogel-PET artificial ligament composite system.

[0052] 5. Post-processing: PVA hydrogel-PET artificial ligament composite system in step 4 is freeze-dried and rehydrated, specifically, the PVA hydrogel-PET artificial ligament composite system after sufficient washing is first placed in a -80°C refrigerator for 6h of pre-freezing, then placed in a freeze dryer with a cold trap temperature of -80°C for 24h of freeze-drying; then the PVA hydrogel-PET artificial ligament composite system after freeze-drying is immersed in 0.01M PBS (pH=7) solution, and is considered to have been fully swollen after 24h of immersion. Through overall freeze-drying and rehydration, the crystal region connection in PVA hydrogel is strengthened, obtaining a gel layer with more reliable mechanical properties, and obtaining the final product (marked as "not stretched").

[0053] Example 4

[0054] According to the method of example 3, the unstretched final product is obtained, and then through 30000 times of axial load cycle stretching (the load is applied by a biomechanical dynamic fatigue tester, the load is output by a motor, the load waveform is a sine waveform, the peak is 100 N, the valley is 50 N, and the loading frequency is 2 Hz) to realize the domestication of the gel layer macromolecular network and eliminate the initial stress relaxation of the composite system, obtaining the final product (marked as "stretched") with macroscopic mechanical properties matching the host bone tissue and micro-topological structure suitable for cell growth.

[0055] Example 5

[0056] 1. Preparation of precursor solution: DMSO, PVA and water are mixed in a certain proportion, and a clear and transparent precursor solution is obtained by stirring in an oil bath at 95°C. The PVA content is 10 w / v %, and the volume ratio of DMSO and water is 3:7.

[0057] 2. Assembly of PET artificial ligament and precursor solution: PET artificial ligament is fully immersed in precursor solution, and vacuum degassing is performed to ensure sufficient contact between precursor solution and PET matrix. The PET artificial ligament is a woven structure obtained by weaving PET fibers.

[0058] 3. Gelation transition: Hollow plastic tube is used as a mold, the artificial ligament braided body is maintained in the center of the hollow plastic tube, after pouring the precursor liquid, together with the mold, braided body, precursor liquid is placed in a low temperature environment (below zero degree) for 12h to complete the gelation transition, and obtain the PVA solvent replacement gel-PET artificial ligament composite system.

[0059] 4. Elution of DMSO: The PVA solvent replacement gel-PET artificial ligament composite system is immersed in pure water to elute DMSO by mechanical stirring and the like, and the water is replaced several times during the process. After sufficient washing, the PVA solvent replacement gel is converted into PVA hydrogel, and the PVA hydrogel-PET artificial ligament composite system is obtained.

[0060] 5. Post-processing: The PVA hydrogel-PET artificial ligament composite system in step 4 is freeze-dried and rehydrated. Specifically, the PVA hydrogel-PET artificial ligament composite system after sufficient washing is first placed in a-80℃ refrigerator for 6h of pre-freezing, and then placed in a freeze dryer with a cold trap temperature of-80℃ for 24h of freeze-drying. Then the PVA hydrogel-PET artificial ligament composite system after freeze-drying is immersed in a 0.01M PBS (pH=7) solution, and is considered to have been sufficiently swollen after 24h of immersion. The whole freeze-drying and rehydration strengthen the crystal region connection in the PVA hydrogel, and a gel layer with more reliable mechanical properties is obtained, and the final product (marked as "not stretched") is obtained.

[0061] Example 6

[0062] The final product is obtained by the method of Example 5, and then the gel layer macromolecular network is domesticated by 30000 times of axial load cycle stretching (the load is applied by a biomechanical dynamic fatigue tester, the load is output by a motor, the load waveform is a sine waveform, the peak is 100 N, the valley is 50 N, and the loading frequency is 2 Hz) to eliminate the initial stress relaxation of the composite system, and the final product (marked as "stretched") with macroscopic mechanical properties matching the host bone tissue and micro-topological structure suitable for cell growth is obtained.

[0063] The final products obtained in Examples 1-6 are scanned by scanning electron microscopy at 500 μm, 100 μm and 10 μm, and the results are shown in Figure 2 and Figure 3 , and Figure 2 are scanning electron micrographs of the products of Examples 1, 3 and 5, Figure 3The scanning electron microscope images of the finished products of Examples 2, 4 and 6. Note: D7H3 refers to the volume ratio of DMSO and water in the precursor solution of the gel layer being 7:3, D5H5 and D3H7 are the same; the meaning of the same description appearing later is the same as explained here and will not be repeated. From Figure 2 and Figure 3 It can be seen that in the PVA-artificial ligament system that is re-swollen and freeze-dried, the PVA gel layer presents a porous morphology; after undergoing cyclic stretching, the D3H7 gel layer obviously has stretching and deformation in the stretching direction; in terms of texture, compared with D3H7, the deformation trend of the D5H5 gel layer is weaker, and the D7H3 gel layer basically maintains the original morphology of the gel layer; in terms of fiber, all of them are significantly multi-level adhesion.

[0064] The finished products obtained in Examples 1-6 were again subjected to scanning electron microscope shooting at 10 μm to observe their respective network structures, and the results are shown in Figure 4 , Figure 4 The scanning electron microscope images of the finished products of Examples 1-6 of the present application. From Figure 4 It can be seen that when observing the gel layer at a scale of 10 μm, it is found that the cyclic stress destroys the fine and low-level PVA network, making the pore size larger. D7H3 has the finest hydrogel cross-linked network, and the energy dissipation effect under dynamic load is the best. The gel layer with a larger average pore size has a better induction effect on cell adhesion and ingrowth.

[0065] The stretched finished products obtained in Examples 2, 4 and 6 were respectively subjected to axial load cyclic stretching to obtain the residual strain changes under dynamic load at the 1000th, 10000th, 20000th and 30000th times, and then the stretched finished products obtained in Examples 2, 4 and 6 were dehydrated and dried with anhydrous ethanol and then scanned by scanning electron microscope, and the results are shown in Figure 5 , Figure 5 The tensile load changes of the stretched finished products obtained in Examples 2, 4 and 6 and the fiber morphology after dehydration and drying. From Figure 5 It can be seen that after 30000 cycles of cyclic load, the residual strain of the stretched finished product obtained in Example 2 is the smallest, followed by the stretched finished product obtained in Example 4, and the residual strain of the stretched finished product obtained in Example 6 is the largest. It is confirmed that the anti-creep effect of the stretched finished product obtained in Example 2 is the best. The surface of the stretched finished product obtained in Example 2 is found to have stripes along the fiber direction, indicating that the D7H3 gel layer has the largest mechanical bearing effect.

[0066] The finished products obtained in Examples 1-6 were subjected to surface stiffness testing, and the experimental conditions were as follows:

[0067] Nanoindenter (Step X00-UNHT3 Bio, Anton Paar, Austria);

[0068] Ruby spherical indenter, 1 mm in diameter;

[0069] Maximum load: 0.1 mN;

[0070] Loading speed: 1 mN / min;

[0071] The results are as follows Figures 6-8 As shown, Figure 6 The images show the indentation depth results after surface stiffness testing of the finished products obtained in Examples 1-6. Figure 7 The graph shows the average surface stiffness results of the finished products obtained in Examples 1-6. Figure 8 This is a surface stiffness distribution diagram of the finished products obtained in Examples 1-6. Figure 6 and Figure 7 It is evident that, under the same braided structure but different gel coatings, the mechanical properties of the gel layer change significantly before and after cyclic stretching. Specifically, before stretching, the surface stiffness of the D7H3 gel layer is significantly higher than that of D3H7, while that of D5H5 is intermediate. This indicates that the initial material distribution of the D3H7 gel layer is lower than that of D5H5, and further lower than that of D7H3. After stretching, the surface stiffness of the D3H7 gel layer is significantly higher than that of D7H3, while that of D5H5 is intermediate. After cyclic stretching, the average pore size of the gel layer increases, and its thickness decreases. Since the initial material distribution of the D3H7 gel layer is lower than that of the other groups, its increased surface stiffness is influenced by the stiffness of the underlying braided structure. The D7H3 group, however, is not significantly affected by the structural stiffness of the underlying braided structure. Figure 8 As can be seen from the nanoindentation test results on the surface of the gel layer, the surface stiffness of the D7H3 group decreased significantly after cyclic stretching. The local rigid environment that originally exceeded the stiffness requirements of the suitable growth environment for bMSCs was eliminated, reaching the level before stretching of D3H7.

[0072] Cell adhesion experiments were performed on the products obtained in Examples 1-6. The specific experimental procedures are as follows:

[0073] Seed cell preparation: Rat bone marrow mesenchymal stem cells (rBMSCs) were used as seed cells and seeded in 24-well plates at a density of 20,000 cells / well and incubated in a cell culture incubator for 12 hours.

[0074] Sample preparation: Cut the samples from Examples 1-6 into lengths of approximately 1 cm, place them in sufficient 75% ethanol, and immerse them in a clean bench under UV irradiation for 24 hours, replacing the ethanol every 12 hours. Subsequently, immerse the materials in 0.01M PBS in a clean bench, wash thoroughly 5 times, and then allow them to stand and soak in PBS for later use.

[0075] Formal experiment: put the samples soaked in PBS into the well plate which has been incubated, 1 sample per well. After 24h incubation, take the samples out of the well plate, wash them gently with PBS, stain the whole samples with live dead stain, and then put them under the laser microscope to observe and calculate the density of adherent cells per unit area.

[0076] The results are shown in Figures 9-11 Figure 9 The scanning electron microscope images of the finished products of examples 1-6 after cell adhesion, Figure 10 The light microscope images of the finished products of examples 1-6 after cell adhesion, Figure 11 The quantitative statistical graphs of the finished products of examples 1-6 after cell adhesion. It can be seen that Figures 9-11 D7H3 group after cyclic stretching. The increase of the average pore size of the gel layer promotes the cell adhesion effect of the sample. The stiffness of the hard matrix will damage the cell adhesion effect. The superposition of the two, the cell adhesion degree of examples 2, 4 and 6 has no significant difference. At the same time, considering that the D7H3 group has the best creep limiting effect, the D7H3 group should be preferred as the current optimal process.

[0077] The residual strain, cell adhesion degree and average surface stiffness test numerical results of the finished products of examples 1-6 are listed in table 1.

[0078] Table 1

[0079]

[0080] In summary, the present application realizes the preparation of PVA micro-phase separation coating on the basis of PET artificial ligament braiding body through micro-phase separation technology. Through the domestication of cyclic stretching in post-processing, the PVA hydrogel layer limits the creep while realizing the shaping of the microenvironment suitable for bMSC adhesion and growth.

[0081] The above is only the preferred specific embodiment of the present application, but the protection scope of the present application is not limited thereto, any skilled person in the art can make equivalent replacement or change according to the technical scheme and the inventive concept of the present application within the technical range disclosed by the present application, which should be covered in the protection scope of the present application.​

Claims

1. An artificial ligament, characterized in that, include: The braided body; the substrate of the braided body is selected from one or more of polyethylene terephthalate fiber, polycaprolactone fiber, aramid fiber, polyetheretherketone fiber, carbon fiber, or silk. PVA hydrogel disposed on the woven body; The PVA hydrogel is obtained by gelling a precursor solution of DMSO, PVA and water and then removing the DMSO; in the precursor solution of DMSO, PVA and water, the content of PVA is 5 w / v%~15 w / v% and the volume ratio of DMSO and water is (8:2)~(2:8). The PVA hydrogel is obtained through the following steps: The braided fabric is immersed in a precursor solution of DMSO, PVA and water, and then the precursor solution containing the braided fabric is placed in a low-temperature environment for gelation transformation; the temperature of the low-temperature environment is above -40°C and below 0°C.

2. The artificial ligament according to claim 1, characterized in that, In the precursor solution of DMSO, PVA and water, the content of PVA is 8 w / v%~12 w / v, and the volume ratio of DMSO and water is (8:2)~(6:4).

3. The artificial ligament according to claim 1, characterized in that, In the precursor solution of DMSO, PVA and water, the content of PVA is 9 w / v%~11 w / v, and the volume ratio of DMSO and water is (7.5:2.5)~(6.5:3.5).

4. The artificial ligament according to claim 1, characterized in that, The PVA hydrogel underwent 5,000 to 50,000 cycles of deformation.

5. A method for preparing an artificial ligament, characterized in that, Includes the following steps: S1) The braided fabric is impregnated in a precursor solution of DMSO, PVA and water, and then the precursor solution containing the braided fabric is placed in a low-temperature environment for gelation transformation; the temperature of the low-temperature environment is above -40°C and below 0°C; in the precursor solution of DMSO, PVA and water, the content of PVA is 5 w / v%~15 w / v%, and the volume ratio of DMSO and water is (8:2)~(2:8); the substrate of the braided fabric is selected from one or more of polyethylene terephthalate fiber, polycaprolactone fiber, aramid fiber, polyetheretherketone fiber, carbon fiber or silk. S2) After washing away DMSO from the material obtained in step S1), freeze-dry it to obtain an artificial ligament.

6. The preparation method according to claim 5, characterized in that, In step S1), the PVA content in the precursor solution of DMSO, PVA and water is 8 w / v%~12 w / v%, and the volume ratio of DMSO and water is (8:2)~(6:4).

7. The preparation method according to claim 5, characterized in that, In step S1), the PVA content in the precursor solution of DMSO, PVA and water is 9 w / v%~11 w / v%, and the volume ratio of DMSO and water is (7.5:2.5)~(6.5:3.5).

8. The preparation method according to claim 5, characterized in that, In step S2), after freeze-drying, the process also includes rehydration, followed by 5,000 to 50,000 cycles of deformation.

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