Injectable self-healing conductive hydrogel and preparation method and application thereof

Abstract

This invention provides an injectable self-healing conductive hydrogel, its preparation method, and its application. The preparation method includes the following steps: (1) mixing a polyvinylpyrrolidone solution with a GLU solution to obtain a mixed solution; (2) adding MXenes to the mixed solution obtained in step (1), and then adjusting the pH to neutral to obtain the injectable self-healing conductive hydrogel. The injectable self-healing conductive hydrogel prepared by this invention can be easily implanted into different parts of the human body and irregular muscle injury areas to fill cavities, and it is expected to become an ideal candidate material for the treatment of muscle injuries.

Description

Technical Field

[0001] This invention belongs to the field of biomaterials and relates to an injectable self-healing conductive hydrogel, its preparation method, and its application. Background Technology

[0002] Muscle injury is caused by sudden contraction or overstretching of muscles during exercise or in poor posture. According to the World Health Organization, approximately 1.71 billion people worldwide suffer from musculoskeletal disorders. Muscle injuries not only lead to decreased muscle strength, muscle atrophy, and pain, but also further impair muscle function after scarring and adhesions, resulting in limited joint mobility and long-term sequelae. Therefore, developing effective treatments for muscle injury recovery is of great significance. Various treatment strategies exist for muscle injuries, including surgical and non-surgical methods such as medication. However, these methods have proven limited in treating complex and multi-layered injuries. Deterioration of the environment surrounding the muscle injury site can lead to inflammation, oxidative damage, bacterial infection, scar adhesions, irregular cystic cavitation, and glial fibrosis. Cystic cavitation and muscle fibrosis block the transmission of electrical signals in muscle tissue and disrupt its electrical connections, becoming major obstacles to fibroblast repair and muscle tissue regeneration. Therefore, improving the microenvironment to promote mesenchymal cell regeneration and differentiation into fibroblasts, thereby repairing muscle injuries, is a significant challenge in the treatment of muscle injuries.

[0003] Injectable hydrogels possess excellent biocompatibility, strong adaptability to minimally invasive surgery, precise positioning and filling capabilities, and ease of handling and storage. They can be directly and accurately injected into wounds without causing secondary damage, making them considered ideal biomaterials for treating muscle injuries. Injectable hydrogels can perfectly fill irregular injury sites and create cysts, thereby promoting fibroblast survival and repair of injured muscle tissue. The porous structure within the hydrogel provides an ideal extracellular microenvironment for substance transport and cell attachment. However, its own movement and external forces may cause the implanted hydrogel structure to break and disintegrate. Therefore, to ensure that the treatment process is not affected by its own movement or external forces, hydrogels with self-healing and adhesive properties have attracted widespread attention.

[0004] PVP (polyvinylpyrrolidone), a water-soluble polymer, possesses excellent biocompatibility and has garnered significant attention in the pharmaceutical industry since its discovery. It is widely used in medicine, disinfection, daily necessities, and food, and is now one of the world's three major pharmaceutical excipients. Gluconic acid, an aldose-glycolic acid derived from glucose, also exhibits good biocompatibility, biodegradability, and low cost. Studies have found that it can stimulate cell growth and repair, thereby promoting wound healing. MXenes (two-dimensional transition metal carbides, nitrides, or carbonitrides), graphene-like two-dimensional materials, have been favored by researchers since their initial discovery in 2011 due to their high conductivity, abundant surface groups, strong hydrophilicity, good biocompatibility, and large specific surface area. Their excellent chemical structure endows them with rich electrochemical, electromagnetic, and mechanical properties, enabling them to play an important role in energy storage materials, sensors, electromagnetic shielding, catalysis, and biomedical applications. However, methods for utilizing these materials to obtain materials suitable for repairing muscle damage have not yet been reported. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the present invention aims to provide an injectable self-healing conductive hydrogel, its preparation method, and its applications. In this invention, the organic molecule GLU (gluconic acid), due to its abundant hydroxyl and carboxyl groups, acts as a crosslinking agent, forming hydrogen bonds with the PVP polymer matrix, ultimately inducing the formation of a three-dimensional physical crosslinking network. This reversible hydrogen bonding gives the PGM hydrogel excellent injectability and self-healing properties. The electroactive material MXenes enhances the hydrogel's conductivity, effectively promoting electrical signal transmission, which is beneficial for fibroblast proliferation and muscle regeneration.

[0006] To achieve this objective, the present invention adopts the following technical solution:

[0007] On one hand, the present invention provides a method for preparing an injectable self-healing conductive hydrogel, the method comprising the following steps:

[0008] (1) Mix the polyvinylpyrrolidone solution with the GLU solution to obtain a mixed solution;

[0009] (2) Add MXenes to the mixed solution obtained in step (1), and then adjust the pH to neutral to obtain the injectable self-healing conductive hydrogel.

[0010] Preferably, the solvent in the polyvinylpyrrolidone solution in step (1) is water.

[0011] Preferably, the concentration of the polyvinylpyrrolidone solution in step (1) is 20%-40%, for example 20%, 25%, 28%, 30%, 33%, 35%, 38% or 40%.

[0012] Preferably, the polyvinylpyrrolidone solution in step (1) is prepared by adding polyvinylpyrrolidone to water and stirring at room temperature for 6-20 hours, for example, 6 hours, 8 hours, 10 hours, 12 hours, 15 hours, 18 hours or 20 hours.

[0013] Preferably, the weight-average molecular weight of the polyvinylpyrrolidone in step (1) is 20,000-25,000, for example, 20,000, 22,000, 24,000 or 25,000.

[0014] Preferably, the GLU solution in step (1) is an aqueous solution of GLU.

[0015] Preferably, the mass percentage concentration of the GLU solution in step (1) is 60% to 70%, for example, 60%, 63%, 65%, 68% or 70%.

[0016] Preferably, the volume ratio of the polyvinylpyrrolidone solution to the GLU solution in step (1) is 2:1 or 3:1.

[0017] Preferably, the MXenes in step (2) are MXenes nanosheets.

[0018] Preferably, the length of the MXene nanosheet is 100-700nm, such as 100nm, 130nm, 150nm, 200nm, 300nm, 400nm, 500nm, 600nm, or 700nm, and the width is 1.9nm-2.5nm, such as 1.9nm, 2.0nm, 2.2nm, 2.4nm, or 2.5nm.

[0019] Preferably, the MXene nanosheets are prepared by etching the MAX phase with an etching reagent, centrifuging, washing the precipitate with water until neutral, adding water for dispersion, and then sonicating the dispersion in an ice-water bath under argon protection, followed by centrifugation, collecting the upper colloidal solution, and freeze-drying to obtain the MXene nanosheets.

[0020] Preferably, the etching reagent is hydrochloric acid and LiF.

[0021] Preferably, the MAX phase is Ti3AlC2.

[0022] As a preferred technical solution, the preparation method of the MXene nanosheets specifically includes the following steps:

[0023] First, 50 mL of 9M hydrochloric acid and 3.2 g of LiF were used as the etching reagent. After stirring for 5 min, 2.0 g of MAX phase (Ti3AlC2) was added in small, repeated additions. The temperature was then raised to 40℃ and stirred for 24 h to ensure thorough etching. After the reaction, the mixture was centrifuged and washed three times with 1M HCl to remove LiF. The precipitate was then repeatedly washed with deionized water until the supernatant was neutral. 50 mL of deionized water was added to further disperse the precipitate, and the mixture was oscillated using a Heidolph Multi Reax shaker for two hours. Finally, the dispersion was sonicated in an ice-water bath under argon protection for 120 min. The dispersion was then centrifuged at 3500 r / min for 1 h, and the upper colloidal solution was collected and freeze-dried to obtain a solid MXene sample.

[0024] Preferably, the final concentration of MXenes in step (2) is 1.0wt%-2.0wt%, for example, 1.0wt%, 1.3wt%, 1.5wt%, 1.8wt%, or 2.0wt%.

[0025] Preferably, the pH adjustment in step (2) is performed using an aqueous sodium hydroxide solution.

[0026] In this invention, after adjusting the pH to neutral in step (2), the mixture is shaken vigorously to form a hydrogel.

[0027] On the other hand, the present invention provides an injectable self-healing conductive hydrogel prepared by the preparation method described above.

[0028] On the other hand, the present invention provides the application of the injectable self-healing conductive hydrogel as described above in the preparation of muscle injury repair materials.

[0029] This invention prepares an injectable, adhesive, and conductive self-healing polyvinylpyrrolidone / gluconic acid / Mxenes (PVP / GLU / Mxenes, PGM) hydrogel for muscle damage repair.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] The injectable self-healing conductive hydrogel prepared in this invention utilizes MXene as the conductive material and employs biocompatible PVP and GLU materials as substrates. The reversible non-covalent interaction between PVP and GLU endows the PGM hydrogel with excellent shear thinning and self-healing properties. The abundant functional groups on the material surface enable it to form multiple interactions with the substrate, exhibiting good adhesion. This hydrogel can be easily implanted into different parts of the human body and into irregular muscle injury areas, filling cavities. Therefore, the multifunctional injectable self-healing conductive hydrogel prepared in this invention shows promise as an ideal candidate material for the treatment of muscle injuries. Detailed Implementation

[0032] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0033] The sources of the materials used in the following embodiments are as follows:

[0034] Polyvinylpyrrolidone: Shanghai Yuang Technology Co., Ltd.; Polyvinylpyrrolidone K30.

[0035] GLU: Shanghai Yuanye Biotechnology Co., Ltd.; D-gluconic acid.

[0036] The preparation method of MXene nanosheets is as follows: First, 50 mL of 9M hydrochloric acid and 3.2 g of LiF were used as etching reagents. After stirring for 5 min, 2.0 g of MAX phase (Ti3AlC2) was added in small amounts several times. Then, the temperature was raised to 40℃ and stirred for 24 h to carry out thorough etching. After the reaction was completed, the mixture was centrifuged and washed three times with 1M HCl to remove LiF. Then, the precipitate was repeatedly washed with deionized water until the supernatant was neutral. Then, 50 mL of deionized water was added to further disperse the precipitate and oscillated using a Heidolph Multi Reax shaker for two hours. Finally, the dispersion was sonicated in an ice-water bath under argon protection for 120 min. Finally, the dispersion was centrifuged at 3500 r / min for 1 h, the upper colloidal solution was collected, and freeze-dried to obtain solid MXene nanosheets.

[0037] Example 1

[0038] This embodiment provides a method for preparing an injectable self-healing conductive hydrogel, the method comprising the following steps:

[0039] (1) Mix an aqueous solution of polyvinylpyrrolidone (concentration of 20%) with an aqueous solution of GLU (concentration of 60wt%) at a volume ratio of 2:1 to obtain a mixed solution;

[0040] (2) Add MXenes nanosheets to the mixed solution obtained in step (1) to make the final concentration of MXenes 1.5 wt%. Then add 0.1 M NaOH aqueous solution to adjust the pH to neutral. After vigorous shaking, the injectable self-healing conductive hydrogel is obtained.

[0041] Example 2

[0042] This embodiment provides a method for preparing an injectable self-healing conductive hydrogel, the method comprising the following steps:

[0043] (1) Mix an aqueous solution of polyvinylpyrrolidone (concentration of 30%) with an aqueous solution of GLU (concentration of 60wt%) at a volume ratio of 2:1 to obtain a mixed solution;

[0044] (2) Add MXenes nanosheets to the mixed solution obtained in step (1) to make the final concentration of MXenes 1.5 wt%. Then add 0.1 M NaOH aqueous solution to adjust the pH to neutral. After vigorous shaking, the injectable self-healing conductive hydrogel is obtained, which has an increased modulus compared to Example 1.

[0045] Example 3

[0046] This embodiment provides a method for preparing an injectable self-healing conductive hydrogel, the method comprising the following steps:

[0047] (1) Mix an aqueous solution of polyvinylpyrrolidone (concentration of 40%) with an aqueous solution of GLU (concentration of 60wt%) at a volume ratio of 2:1 to obtain a mixed solution;

[0048] (2) Add MXenes nanosheets to the mixed solution obtained in step (1) to make the final concentration of MXenes 1.5 wt%. Then add 0.1 M NaOH aqueous solution to adjust the pH to neutral. After vigorous shaking, the injectable self-healing conductive hydrogel is obtained, and its modulus is further increased compared with Example 2.

[0049] Example 4

[0050] This embodiment provides a method for preparing an injectable self-healing conductive hydrogel, the method comprising the following steps:

[0051] (1) Mix an aqueous solution of polyvinylpyrrolidone (concentration of 30%) with an aqueous solution of GLU (concentration of 60wt%) at a volume ratio of 2:1 to obtain a mixed solution;

[0052] (2) Add MXenes nanosheets to the mixed solution obtained in step (1) to make the final concentration of MXenes 1.0 wt%, and then add 0.1 M NaOH aqueous solution to adjust the pH to neutral. After vigorous shaking, the injectable self-healing conductive hydrogel is obtained.

[0053] Example 5

[0054] This embodiment provides a method for preparing an injectable self-healing conductive hydrogel, the method comprising the following steps:

[0055] (1) Mix an aqueous solution of polyvinylpyrrolidone (concentration of 30%) with an aqueous solution of GLU (concentration of 60wt%) at a volume ratio of 2:1 to obtain a mixed solution;

[0056] (2) Add MXenes nanosheets to the mixed solution obtained in step (1) to make the final concentration of MXenes 0% wt%, and then add 0.1M NaOH aqueous solution to adjust the pH to neutral. After vigorous shaking, the injectable self-healing conductive hydrogel is obtained, and the conductivity is enhanced compared with Example 4.

[0057] Example 6

[0058] This embodiment provides a method for preparing an injectable self-healing conductive hydrogel, the method comprising the following steps:

[0059] (1) Mix an aqueous solution of polyvinylpyrrolidone (concentration of 30%) with an aqueous solution of GLU (concentration of 60wt%) at a volume ratio of 2:1 to obtain a mixed solution;

[0060] (2) Add MXenes nanosheets to the mixed solution obtained in step (1) to make the final concentration of MXenes 2.0 wt%. Then add 0.1 M NaOH aqueous solution to adjust the pH to neutral. After vigorous shaking, the injectable self-healing conductive hydrogel is obtained. The increase of Mxene material leads to excessive crowding and mutual interference of conductive pathways. The resistance no longer continues to decrease, and the conductivity is lower than that of Example 5.

[0061] Comparative Example 1

[0062] A 30% aqueous solution of polyvinyl alcohol (Jiangsu Pules Biotechnology Co., Ltd., 99% purity, 1 kg) and a 60 wt% aqueous solution of GLU were mixed at a volume ratio of 2:1. Mxene nanosheets were then added to the mixed solution, resulting in a final Mxene concentration of 1.5 wt%. 0.1 M NaOH aqueous solution was then added to adjust the pH to neutral. After vigorous shaking, a hydrogel was obtained. However, PVA can affect normal cell metabolism and proliferation at wound sites, resulting in certain cytotoxicity.

[0063] Comparative Example 2

[0064] An aqueous solution of polyacrylic acid (Guangdong Qianjin Chemical Reagent Co., Ltd., purity 99%, 1 kg) (concentration 30%) and an aqueous solution of GLU (concentration 60 wt%) were mixed at a volume ratio of 2:1. After obtaining the mixed solution, Mxene nanosheets were added, and the final concentration of Mxene was 1.5 wt%. Then, 0.1 M NaOH aqueous solution was added to adjust the pH to neutral. After vigorous shaking, a hydrogel was obtained. However, PAA can bind to proteins in the blood at the wound site, changing the structure and function of the proteins, thereby affecting the normal coagulation and transport function of the blood.

[0065] Comparative Example 3

[0066] An aqueous solution of polyvinylpyrrolidone (30% concentration) and an aqueous solution of GLU (60 wt% concentration) were mixed at a volume ratio of 2:1. After obtaining the mixed solution, freeze-dried graphene (Jiangsu Xianfeng Nanomaterials Technology Co., Ltd.) was added, and the final concentration of graphene was 1.5 wt%. Then, 0.1M NaOH aqueous solution was added to adjust the pH to neutral. After vigorous shaking, a hydrogel was obtained. After the graphene redissolved, it did not completely return to the state before freeze-drying, and agglomeration and stacking occurred, which ultimately led to a decrease in the conductivity of the hydrogel.

[0067] The hydrogels prepared in the examples and comparative examples were subjected to performance tests, and the test methods are as follows:

[0068] (1) Modulus test: The modulus and viscosity of the hydrogel were measured using a rotational rheometer (DHR-1). 1 mL of the corresponding gel was added to a 40 mm plate for testing (plate gap: 1 mm; temperature: 298 K; storage loss modulus test parameters: angular frequency set to 0.1~100 rad / s; logarithmic scan mode).

[0069] (2) Alamarblue cell viability assay: using 5 × 10⁻⁶ cells per cell. 5 C2C12 cells were cultured by spreading them evenly on a hydrogel. Day 1 was designated as the first day of encapsulation. On Day 2, 0.1 mL of DMEM / AlamarBlue working solution (DMEM / AlamarBlue = 10 / 1) was added to the cell gel, the cell-free gel, and the blank wells. After incubation for 5 hours, the supernatant was transferred to a new 96-well plate and measured using an ELISA reader.

[0070] (3) Conductivity test (four-electrode method): Fix four electrodes on the sample according to the specified spacing and arrangement; then, apply a stable current to the current electrode; next, measure the voltage between the voltage electrodes with a high impedance voltmeter; finally, calculate the conductivity according to Ohm's law and the geometric dimensions of the sample.

[0071] (4) Hemolysis test: Centrifuge anticoagulated whole blood at a low speed (1000-1500 rpm) for 5-10 minutes to precipitate blood cells, then discard the supernatant. Wash red blood cells 2-3 times with physiological saline, adding an equal volume of physiological saline each time, gently inverting to mix, then centrifuging again and discarding the supernatant. Finally, prepare a 2.5% red blood cell suspension with physiological saline for later use. Add 0.5 ml of hydrogel to each of a series of clean test tubes, then add 2 ml of red blood cell suspension to each tube, gently inverting to mix, ensuring the solution fully contacts the red blood cells. Incubate the test tubes at 37°C for 2 hours, gently shaking the tubes occasionally to ensure sufficient reaction between the red blood cells and the test solution. Hemolysis can then be observed visually.

[0072] The test results are shown in Table 1.

[0073] Table 1

[0074]

[0075]

[0076] The applicant declares that this invention illustrates the injectable self-healing conductive hydrogel, its preparation method, and its application through the above embodiments. However, this invention is not limited to the above embodiments, meaning that this invention does not necessarily rely on the above embodiments for implementation. Those skilled in the art should understand that any improvements to this invention, equivalent substitutions of the raw materials in the product, addition of auxiliary components, and selection of specific methods all fall within the protection and disclosure scope of this invention.

Claims

1. A method for preparing an injectable self-healing electrically conductive hydrogel, characterized in that, The preparation method comprises the following steps: (1) mixing a polyvinylpyrrolidone solution with a gluconic acid GLU solution to obtain a mixed solution; (2) adding MXenes to the mixed solution obtained in step (1), and then adjusting the pH to neutral to obtain the injectable self-healing conductive hydrogel; In step (1), the weight average molecular weight of the polyvinylpyrrolidone is 20,000-25,000.

2. The production method according to claim 1, characterized by, In step (1), the solvent in the polyvinylpyrrolidone solution is water.

3. The production method according to claim 1, characterized by, In step (1), the concentration of the polyvinylpyrrolidone solution is 20%-40%.

4. The method of claim 1, wherein, In step (1), the polyvinylpyrrolidone solution is prepared by adding polyvinylpyrrolidone to water and stirring at room temperature for 6-20 hours.

5. The preparation method according to claim 1, characterized in that, In step (1), the GLU solution is an aqueous GLU solution.

6. The method of claim 1, wherein, In step (1), the mass percentage concentration of the GLU solution is 60%-70%.

7. The preparation method according to claim 1, characterized in that, In step (1), the mixing volume ratio of the polyvinylpyrrolidone solution to the GLU solution is 2:1 or 3:

1.

8. The method of claim 1, wherein, In step (2), the MXenes are MXenes nanosheets.

9. The production method according to claim 8, characterized by, The length of the MXene nanosheet is 100-700 nm, and the width is 1.9-2.5 nm.

10. The preparation method according to claim 8, characterized in that, The preparation method of the MXene nanosheet is: etching a MAX phase with an etching reagent, then centrifuging, washing the precipitate with water until neutral, adding water for dispersion, then under the protection of argon, ultrasonic treatment of the dispersion liquid in an ice water bath, then centrifuging, collecting the upper colloidal solution, freeze-drying to obtain the MXene nanosheet.

11. The method of claim 10, wherein, The etching reagent is hydrochloric acid and LiF.

12. The method of claim 10, wherein, The MAX phase is Ti3AlC2.

13. The method of claim 1, wherein, In step (2), the final concentration of the MXenes is 1.0wt%-2.0wt%.

14. The method of claim 1, wherein, In step (2), the pH adjustment is performed using a sodium hydroxide aqueous solution.

15. The method of claim 1, wherein, After adjusting the pH to neutral in step (2), the hydrogel is formed after shaking.

16. The injectable self-healing conductive hydrogel prepared by the preparation method according to any one of claims 1-15.

17. The use of the injectable self-healing conductive hydrogel according to claim 16 in the preparation of a muscle injury repair material.

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