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

Abstract

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

Description

Technical Field

[0001] The invention belongs to the field of biomaterials and relates to an injectable self-healing conductive hydrogel and a preparation method and application thereof. Background Art

[0002] Muscle injury is the injury caused by the sharp contraction or excessive stretching of muscles during exercise or bad posture. According to statistics from the World Health Organization, about 1.71 billion people suffer from musculoskeletal diseases worldwide. Muscle injury not only causes muscle strength loss, muscle atrophy and pain, but also further affects muscle function after the formation of scars and adhesions, which in turn limits joint functional activities and leaves sequelae. Therefore, it is of great significance to develop effective treatment methods for muscle injury recovery. There are many treatment strategies for muscle injury, such as surgical treatment and non-surgical methods such as drug therapy. However, these methods have been shown to have limitations in the treatment of complex and multi-faceted injuries. The deterioration of the environment around the muscle injury site can lead to inflammation, oxidative damage, bacterial infection, scar adhesion, irregular cystic cavitation and glial fibrosis. Cystic cavitation and muscle fibrosis block the transmission of electrical signals in muscle tissue, destroy the electrical connection of muscle tissue, and become the main obstacle to the regeneration of muscle tissue by fibroblasts. Therefore, how to improve the microenvironment, promote the regeneration and differentiation of mesenchymal cells into fibroblasts, and then repair muscle injury is a major challenge in the treatment of muscle injury.

[0003] Injectable hydrogels have good biocompatibility, strong adaptability to minimally invasive surgery, can be accurately positioned and filled, and are easy to operate and store. They can be directly and accurately injected into the wound without causing secondary damage, and are considered to be ideal biomaterials for treating muscle injuries. Injectable hydrogels can perfectly fill irregular injury sites and build cysts, thereby promoting the survival of fibroblasts and the repair of injured muscle tissue. The porous structure inside the hydrogel can provide an ideal extracellular microenvironment for material transport and cell attachment. However, self-motion and interference from external forces may cause the implanted hydrogel structure to break and then fall apart. Therefore, in order to ensure that the treatment process is not affected by self- and external interference, hydrogels with self-healing adhesion properties have attracted widespread attention.

[0004] PVP (polyvinyl pyrrolidone) is a water-soluble polymer material with excellent physiological compatibility. Once it came out, it has been valued by the medical community and has been widely used in medicine, disinfection, daily necessities and food. It has now become one of the three major pharmaceutical excipients in the world; gluconic acid, as an aldose acid converted from glucose, also has good biocompatibility, degradability and low cost. Studies have found that it can also stimulate cell growth and repair to promote wound healing; MXenes (two-dimensional transition metal carbides, nitrides or carbonitrides) are a two-dimensional material similar to graphene. After being first discovered in 2011, it has been favored by a large number of scientific researchers for its high conductivity, rich surface groups, strong hydrophilicity, good biocompatibility and large specific surface area. Its excellent chemical structure characteristics give it rich electrochemical, electromagnetic properties and mechanical properties, making it play an important role in energy storage materials, sensors, electromagnetic shielding, catalysis and biomedicine. How to use these materials to obtain materials that can be used to repair muscle damage has not been reported yet. Summary of the invention

[0005] In view of the deficiencies of the prior art, the purpose of the present invention is to provide an injectable self-healing conductive hydrogel and its preparation method and application. In the present invention, the organic molecule GLU (gluconic acid) has abundant hydroxyl and carboxyl groups, and forms hydrogen bonds with the PVP polymer matrix as a cross-linking agent, and finally induces the formation of a three-dimensional physical cross-linking network. The reversible hydrogen bond connection makes the PGM hydrogel have good injectability and self-healing properties; the electroactive material MXenes can improve the conductivity of the hydrogel, effectively promote the transmission of electrical signals, and is beneficial to the proliferation of fibroblasts and promotes the regeneration of muscle damage.

[0006] To achieve this object, the present invention adopts the following technical solutions:

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

[0008] (1) mixing the polyvinyl pyrrolidone solution and the GLU solution to obtain a mixed solution;

[0009] (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.

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

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

[0012] Preferably, the polyvinyl pyrrolidone solution in step (1) is prepared by adding polyvinyl pyrrolidone into 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 polyvinyl pyrrolidone 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 mixing volume ratio of the polyvinyl pyrrolidone solution and 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 MXene nanosheet has a length of 100-700 nm, such as 100 nm, 130 nm, 150 nm, 200 nm, 300 nm, 400 nm, 500 nm, 600 nm, 700 nm, and a width of 1.9 nm-2.5 nm, such as 1.9 nm, 2.0 nm, 2.2 nm, 2.4 nm or 2.5 nm.

[0019] Preferably, the preparation method of the MXene nanosheet is: etching the MAX phase with an etching reagent, followed by centrifugation, washing the precipitate with water until it is neutral, adding water for dispersion, and then ultrasonically treating the dispersion in an ice water bath under the protection of argon gas, followed by centrifugation, collecting the colloidal solution in the upper layer, and freeze-drying to obtain the MXene nanosheet.

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

[0021] Preferably, the MAX phase is Ti3AlC2.

[0022] As a preferred technical solution, the method for preparing the MXene nanosheets specifically comprises the following steps:

[0023] First, 50mL of 9M hydrochloric acid and 3.2g LiF were used as etching reagents. After stirring for 5min, 2.0g MAX phase (Ti3AlC2) was added in small amounts and multiple times. Then the temperature was raised to 40°C and stirred for 24h for sufficient etching. After the reaction, the mixture was centrifuged and washed three times with 1M HCl to remove LiF. After that, the precipitate was repeatedly washed with deionized water until the supernatant was neutral. Then 50mL of deionized water was added to further disperse the precipitate and mediated for two hours using a Heidolph Multi Reax oscillator. Finally, under the protection of argon, the dispersion was ultrasonically treated in an ice water bath. The ultrasonic treatment time was 120min. Finally, the dispersion was centrifuged at a speed of 3500r / min for 1h, the colloidal solution on the upper layer was collected, and a solid MXene sample was obtained after freeze-drying.

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

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

[0026] In the present invention, after the pH is adjusted to neutral in step (2), the hydrogel is formed after vigorous shaking.

[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 use of the injectable self-healing conductive hydrogel as described above in the preparation of muscle injury repair materials.

[0029] The invention prepares an injectable, adhesive and conductive self-repairing polyvinyl pyrrolidone / gluconic acid / Mxenes (PVP / GLU / Mxenes, PGM) hydrogel for repairing muscle damage.

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

[0031] The injectable self-healing conductive hydrogel prepared by the present invention uses MXene as a conductive material, and uses PVP material and GLU material with good biocompatibility as a substrate. The reversible non-covalent interaction between PVP and GLU enables the PGM hydrogel to have excellent shear thinning and self-healing properties. The rich groups on the surface of the material enable it to form multiple interactions with the substrate and show good adhesion. This hydrogel can be easily implanted into different parts of the human body and irregular muscle injury areas, and fill the cavity. Therefore, the multifunctional injectable self-healing conductive hydrogel prepared by the present invention is expected to become an ideal candidate material for the treatment of muscle injuries. DETAILED DESCRIPTION

[0032] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

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

[0034] Polyvinyl pyrrolidone: Shanghai Yuang Technology Co., Ltd.; povidone K30.

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

[0036] The preparation method of MXenes nanosheets is as follows: First, 50mL of 9M hydrochloric acid and 3.2g LiF are used as etching reagents. After stirring for 5min, 2.0g MAX phase (Ti3AlC2) is added in small amounts and multiple times. Then the temperature is raised to 40°C and stirred for 24h for sufficient etching. After the reaction is completed, the mixture is centrifuged and washed three times with 1MHCl to remove LiF. After that, the precipitate is repeatedly washed with deionized water until the supernatant is neutral. Then 50mL of deionized water is added to further disperse the precipitate and the HeidolphMulti Reax oscillator is used for two hours. Finally, under the protection of argon, the dispersion is ultrasonically treated in an ice water bath. The ultrasonic treatment time is 120min. Finally, the dispersion is centrifuged at a speed of 3500r / min for 1h, the colloidal solution on the upper layer is collected, and solid MXene nanosheets are obtained after freeze-drying.

[0037] Example 1

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

[0039] (1) mixing an aqueous solution of polyvinyl pyrrolidone (concentration: 20%) and an aqueous solution of GLU (concentration: 60 wt %) at a volume ratio of 2:1 to obtain a mixed solution;

[0040] (2) Adding MXenes nanosheets to the mixed solution obtained in step (1) to make the final concentration of MXenes 1.5 wt%, and then adding 0.1 M NaOH aqueous solution to adjust the pH to neutral, and 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 preparation method comprising the following steps:

[0043] (1) mixing an aqueous solution of polyvinyl pyrrolidone (concentration: 30%) and an aqueous solution of GLU (concentration: 60 wt %) at a volume ratio of 2:1 to obtain a mixed solution;

[0044] (2) Adding MXenes nanosheets to the mixed solution obtained in step (1) to make the final concentration of MXenes 1.5 wt%, and then adding 0.1 M NaOH aqueous solution to adjust the pH to neutral, and after vigorous shaking, the injectable self-healing conductive hydrogel is obtained, and its modulus is increased compared with Example 1.

[0045] Example 3

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

[0047] (1) mixing an aqueous solution of polyvinyl pyrrolidone (concentration: 40%) and an aqueous solution of GLU (concentration: 60 wt %) at a volume ratio of 2:1 to obtain a mixed solution;

[0048] (2) Adding MXenes nanosheets to the mixed solution obtained in step (1) to make the final concentration of MXenes 1.5 wt%, and then adding 0.1 M NaOH aqueous solution to adjust the pH to neutral, and 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 preparation method comprising the following steps:

[0051] (1) mixing an aqueous solution of polyvinyl pyrrolidone (concentration: 30%) and an aqueous solution of GLU (concentration: 60 wt %) at a volume ratio of 2:1 to obtain a mixed solution;

[0052] (2) Adding MXenes nanosheets to the mixed solution obtained in step (1) to make the final concentration of MXenes 1.0 wt%, and then adding 0.1 M NaOH aqueous solution to adjust the pH to neutral, and 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 preparation method comprising the following steps:

[0055] (1) mixing an aqueous solution of polyvinyl pyrrolidone (concentration: 30%) and an aqueous solution of GLU (concentration: 60 wt %) at a volume ratio of 2:1 to obtain a mixed solution;

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

[0057] Example 6

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

[0059] (1) mixing an aqueous solution of polyvinyl pyrrolidone (concentration: 30%) and an aqueous solution of GLU (concentration: 60 wt %) at a volume ratio of 2:1 to obtain a mixed solution;

[0060] (2) MXenes nanosheets were added to the mixed solution obtained in step (1) to make the final concentration of MXenes 2.0 wt%, and then 0.1 M NaOH aqueous solution was added to adjust the pH to neutral. After vigorous shaking, the injectable self-healing conductive hydrogel was obtained. The increase of MXene material caused the conductive pathways to be overcrowded and interfered with each other, and the resistance no longer continued to decrease. The conductive performance was reduced compared with Example 5.

[0061] Comparative Example 1

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

[0063] Comparative Example 2

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

[0065] Comparative Example 3

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

[0067] The performance of the hydrogels prepared in the examples and comparative examples was tested in the following manner:

[0068] (1) Modulus detection: 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 flat 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 scanning mode).

[0069] (2) Alamarblue cell viability assay: 5×10 5 C2C12 cells were plated on the hydrogel at a cell density of 10 cells / mL for cell culture, and the first day of encapsulation was set as Day 1. On Day 2, 0.1 mL of DMEM / AlamarBlue working solution (DMEM / AlamarBlue=10 / 1) was added to the cell gel, the gel without cells and the blank wells. After incubation for 5 hours, the supernatant was transferred to a new 96-well plate and measured using an enzyme-linked immunosorbent assay.

[0070] (3) Conductivity test (four-electrode method): Four electrodes are fixed on the sample at a specified spacing and arrangement. Then, a stable current is applied to the current electrode. Next, a high-impedance voltmeter is used to measure the voltage between the voltage electrodes. Finally, the conductivity is calculated based on Ohm's law and the geometric dimensions of the sample.

[0071] (4) Hemolysis test: Centrifuge the anticoagulated whole blood in a low-speed centrifuge (1000-1500rpm) for 5-10 minutes to precipitate the blood cells, and then discard the upper plasma. Wash the red blood cells with saline for 2-3 times, adding an equal volume of saline each time, gently inverting to mix, and then centrifuging, and discard the supernatant. Finally, the washed red blood cells are prepared with saline to a 2.5% red blood cell suspension for use. Add 0.5ml of hydrogel to a series of clean test tubes, and then add 2ml of red blood cell suspension to each test tube, gently invert to mix, so that the solution is fully in contact with the red blood cells, and incubate the test tube at 37°C for 2 hours. During this period, gently shake the test tube appropriately to ensure that the red blood cells react fully with the test solution, and then observe the hemolysis phenomenon with the naked eye.

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

[0073] Table 1

[0074]

[0075]

[0076] The applicant declares that the present invention illustrates the injectable self-healing conductive hydrogel and its preparation method and application through the above embodiments, but the present invention is not limited to the above embodiments, that is, it does not mean that the present invention must rely on the above embodiments to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of various raw materials of the product of the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A method for preparing an injectable self-healing conductive hydrogel, characterized in that: The preparation method comprises the following steps: (1) mixing the polyvinyl pyrrolidone solution and the 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.

2. The preparation method according to claim 1, characterized in that: The solvent in the polyvinyl pyrrolidone solution in step (1) is water; Preferably, the concentration of the polyvinyl pyrrolidone solution in step (1) is 20% to 40%.

3. The preparation method according to claim 1 or 2, characterized in that: The polyvinyl pyrrolidone solution in step (1) is prepared by adding polyvinyl pyrrolidone into water and stirring at room temperature for 6-20 hours; Preferably, the weight average molecular weight of the polyvinyl pyrrolidone in step (1) is 20,000-25,000.

4. The preparation method according to any one of claims 1 to 3, characterized in that The GLU solution in step (1) is an aqueous solution of GLU; Preferably, the mass percentage concentration of the GLU solution in step (1) is 60% to 70%.

5. The preparation method according to any one of claims 1 to 4, characterized in that: The mixing volume ratio of the polyvinyl pyrrolidone solution and the GLU solution in step (1) is 2:1 or 3:

1.

6. The preparation method according to any one of claims 1 to 5, characterized in that: The MXenes in step (2) are MXenes nanosheets; Preferably, the MXene nanosheet has a length of 100-700 nm and a width of 1.9-2.5 nm.

7. The preparation method according to any one of claims 1 to 6, characterized in that: The preparation method of the MXene nanosheet is as follows: etching the MAX phase with an etching agent, then centrifuging, washing the precipitate with water until it is neutral, adding water to disperse it, and then ultrasonically treating the dispersion in an ice water bath under the protection of argon gas, then centrifuging, collecting the colloidal solution in the upper layer, and freeze-drying to obtain the MXene nanosheet; Preferably, the etching reagent is hydrochloric acid and LiF; Preferably, the MAX phase is Ti3AlC2.

8. The preparation method according to any one of claims 1 to 7, characterized in that: The final concentration of the MXenes in step (2) is 1.0 wt%-2.0 wt%; Preferably, the pH adjustment in step (2) is performed using an aqueous sodium hydroxide solution; Preferably, after adjusting the pH to neutral in step (2), the mixture is shaken to form a hydrogel.

9. The injectable self-healing conductive hydrogel prepared by the preparation method according to any one of claims 1 to 8.

10. Use of the injectable self-healing conductive hydrogel according to claim 9 in preparing muscle damage repair materials.

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