A tourmaline particle composite hydrogel, its preparation method and application

Abstract

The present invention discloses a tourmaline particle composite hydrogel, its preparation method and application. In the present invention, tourmaline particles are used as functional additives and introduced into a hydrogel matrix composed of chitosan and polyvinyl alcohol. By combining the method of repeated freezing and thawing, the physical cross-linking is enhanced by tourmaline particles, and the surface charge distribution, antibacterial and cell proliferation-stimulating functions of the hydrogel are regulated. Without introducing a chemical cross-linking agent, a tourmaline / chitosan / polyvinyl alcohol composite hydrogel with a three-dimensional network structure, good biocompatibility, remarkable in vitro coagulation and antibacterial effects can be prepared, which can be used as a wound dressing and artificial cartilage.

Description

Technical Field

[0001] The present invention belongs to the field of biomedical materials, and particularly relates to a tourmaline particle composite hydrogel, a preparation method thereof, and an application thereof. Background Art

[0002] In the process of social activities, the human skin will inevitably be damaged by trauma such as dehydration, mechanical, chemical damage, and microbial infection. When the skin is damaged, the organizational structure of collagen fibers will be destroyed and needs to be repaired. Before the self-repair of the skin, a wound dressing with good performance can be used to temporarily replace the skin, provide a good environment for the wound surface, and promote wound healing. An ideal wound dressing should have the following functions: (1) good air permeability and moisture retention; (2) easy adhesion to the wound tissue; (3) soft and with certain mechanical strength; (4) significant hemostatic and antibacterial effects; (5) good biocompatibility.

[0003] The hydrogel crosslinked by hydrogen bonds, covalent bonds, and electrostatic forces has a three-dimensional network structure, can swell in water without losing the integrity of the structure, has good softness, air permeability, and liquid absorption and retention properties, can absorb the exudate of the wound tissue surface, and keep the environment around the wound moist; and is easy to use, and is easy to separate from the tissue surface after wound healing, reducing the pain of the patient. Chitosan is non-toxic, non-antigenic, and has no hemolytic effect, has good adhesion and biocompatibility, and at the same time has multiple functions such as hemostasis and blood coagulation, antibacterial and anti-inflammatory. Polyvinyl alcohol not only has excellent mechanical properties, but also has significant biodegradability, thermal stability, and biocompatibility. The chitosan / polyvinyl alcohol hydrogel prepared by blending chitosan and polyvinyl alcohol can combine the respective advantages and is widely used in the field of wound dressings.

[0004] The amino groups in the chitosan / polyvinyl alcohol hydrogel carry a positive charge, which can promote the adhesion of negatively charged red blood cells through electrostatic interaction, induce the aggregation and activation of platelets, and thus promote blood coagulation. However, endogenous blood coagulation requires the activation of negative charges, and there is still room for improvement in the hemostatic efficiency of the hydrogel. Although the chitosan / polyvinyl alcohol hydrogel has the property of active antibacterial, its antibacterial effect is very limited. At present, most hydrogels will introduce chemical cross-linking agents during the preparation process, and the cross-linking agents have certain toxicity, which will affect the biocompatibility of the hydrogel. The literature with the application number 202111178160.1 discloses a modified chitosan-polyvinyl alcohol composite antibacterial hydrogel and its preparation method. The composite hydrogel uses diisocyanate as a cross-linking agent, and the hydrogel has good mechanical properties and antibacterial effects. In the literature "Chen H L, Cheng J W, Ran L X, et al. An injectable self-healing hydrogel with adhesive and antibacterial properties effectively promotes wound healing[J]. Carbohydrate polymers, 2018, 201: 522-531.", a Schiff base bond is formed between chitosan and oxidized konjac glucoside to prepare an injectable hydrogel material. The hydrogel shows significant antibacterial effects against Escherichia coli and Staphylococcus aureus, and animal experiments show that the hydrogel material has the effect of promoting wound healing. The hydrogels prepared in the above studies all use chemical cross-linking methods to achieve cross-linking between molecular chains. However, the chemical cross-linking method is irreversible, and the introduction of chemical cross-linking agents will affect the biocompatibility of the hydrogel. Summary of the Invention

[0005] Aiming at the deficiencies of the prior art, the technical problem to be solved by the present invention is to provide a tourmaline particle composite hydrogel, its preparation method and application.

[0006] The technical solution of the present invention to solve the above technical problem of the method is to provide a preparation method of a tourmaline particle composite hydrogel, which is characterized in that the method includes the following steps:

[0007] (1) Prepare a chitosan solution and a polyvinyl alcohol solution;

[0008] (2) Mix the chitosan solution and the polyvinyl alcohol solution and stir evenly to obtain a chitosan / polyvinyl alcohol solution;

[0009] (3) Add tourmaline particles to a mixed solvent of deionized water and glacial acetic acid, and ultrasonic treatment is carried out to uniformly disperse the tourmaline particles in the mixed solvent to prepare a tourmaline particle suspension;

[0010] (4) While performing ultrasonic and stirring treatments, gradually add the tourmaline particle suspension dropwise into the chitosan / polyvinyl alcohol solution, and then continue with ultrasonic and stirring treatments to evenly disperse the tourmaline particles, obtaining a tourmaline / chitosan / polyvinyl alcohol mixture;

[0011] (5) Freeze the tourmaline / chitosan / polyvinyl alcohol mixture and then thaw it to complete one freeze-thaw cycle; Repeat the freeze-thaw cycle several times to obtain a composite;

[0012] (6) Place the composite in absolute ethanol and dehydrate and dry the composite to obtain a tourmaline particle composite hydrogel.

[0013] The technical solution of the present invention to solve the technical problem of the composite hydrogel is to provide a tourmaline particle composite hydrogel prepared by the above method.

[0014] The technical solution of the present invention to solve the technical problem of the application is to provide an application of the tourmaline particle composite hydrogel, characterized in that the tourmaline particle composite hydrogel is applied to wound dressings or artificial cartilage.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0016] (1) The present invention introduces tourmaline particles as functional additives into the hydrogel matrix composed of chitosan and polyvinyl alcohol, and combines the method of repeated freeze-thaw. Through the tourmaline particles, physical cross-linking is enhanced, and the surface charge distribution, antibacterial and cell proliferation-stimulating functions of the hydrogel are regulated. Without introducing chemical cross-linking agents, a tourmaline / chitosan / polyvinyl alcohol composite hydrogel with a three-dimensional network structure, good biocompatibility, significant in vitro coagulation and antibacterial effects can be prepared, and it can be used as a wound dressing.

[0017] (2) The present invention uses the freeze-thaw method for preparation, and the preparation process is simple, with low cost, high production efficiency, and can achieve mass production.

[0018] (3) The composite hydrogel provided by the present invention does not require the introduction of chemical cross-linking agents, does not contain toxic or irritating substances, and has excellent biocompatibility; by introducing tourmaline particles, the function of activating endogenous coagulation of the hydrogel is increased, and the in vitro coagulation performance of the hydrogel is improved; the introduction of tourmaline particles can increase the antibacterial rate of the hydrogel; moreover, it is convenient to use and has low cost, and can be used as a wound dressing.

[0019] (4) The composite hydrogel provided by the present invention has a three-dimensional network structure and a more stable structure.

[0020] (5) The present invention improves the swelling performance of the hydrogel by introducing tourmaline particles. The hydrogel has good swelling performance, and the swelling ratio after reaching swelling equilibrium is 181%. Description of the Drawings

[0021] Figure 1 is the scanning electron microscope image of the composite hydrogel prepared in Example 1 of the present invention;

[0022] Figure 2 is the scanning electron microscope image of the composite hydrogel prepared in Example 2 of the present invention;

[0023] Figure 3 is the scanning electron microscope image of the composite hydrogel prepared in Example 3 of the present invention;

[0024] Figure 4 is the scanning electron microscope image of the hydrogel prepared in Comparative Example 1 of the present invention;

[0025] Figure 5 is the swelling curves of the hydrogels prepared in Examples 1 - 3 and Comparative Example 1 of the present invention in PBS solution over time. Detailed Description of the Invention

[0026] The following are specific examples of the present invention. The specific examples are only used for further detailed description of the present invention and do not limit the protection scope of the claims of the present invention.

[0027] The present invention provides a method for preparing a tourmaline particle composite hydrogel (hereinafter referred to as the method), which is characterized in that the method comprises the following steps:

[0028] (1) Prepare a chitosan solution and a polyvinyl alcohol solution:

[0029] Dissolve chitosan in a mixed solvent of deionized water and glacial acetic acid, and stir evenly to obtain a chitosan solution;

[0030] Mix polyvinyl alcohol and deionized water, and stir evenly to obtain a polyvinyl alcohol solution;

[0031] Preferably, in step (1), the concentration of the chitosan solution is 0.01 - 0.05 g / mL, the temperature for preparing the chitosan solution is 20 - 30 °C, and the stirring time is 4 - 6 h.

[0032] Preferably, in step (1), the molecular weight of chitosan is 50 - 150×10 4 ;

[0033] Preferably, in step (1), the volume ratio of deionized water to glacial acetic acid is 1 - 30:1 - 5 (preferably 24:1).

[0034] Preferably, in step (1), the concentration of the polyvinyl alcohol solution is 0.05 - 0.15 g / mL, the temperature for preparing the polyvinyl alcohol solution is 85 - 100 °C, and the stirring time is 4 - 6 h.

[0035] (2) Prepare the chitosan / polyvinyl alcohol solution: Mix the chitosan solution and the polyvinyl alcohol solution, and stir evenly to obtain a homogeneous chitosan / polyvinyl alcohol solution;

[0036] Preferably, in step (2), the volume ratio of the chitosan solution to the polyvinyl alcohol solution is 1-5:1-5 (preferably 1:1), the temperature for preparing the chitosan / polyvinyl alcohol solution is room temperature (i.e., 20-30 °C), and the stirring time is 4-6 h.

[0037] (3) Prepare the tourmaline particle suspension: Add tourmaline particles to the mixed solvent of deionized water and glacial acetic acid, and ultrasonically treat to uniformly disperse the tourmaline particles in the mixed solvent to prepare a tourmaline particle suspension;

[0038] Preferably, in step (3), the particle size of the tourmaline particles is 10 nm to 5 μm (preferably 10 nm to 100 nm).

[0039] Preferably, in step (3), the mass of the tourmaline particles is 1-20% (preferably 1-10%) of the sum of the masses of chitosan and polyvinyl alcohol.

[0040] Preferably, in step (3), the ultrasonic process is intermittent ultrasonic treatment for 15-35 min at a frequency of 10-100 kHz (preferably 20-25 kHz) and a power of 20-2000 W (preferably 50-250 W); during the intermittent ultrasonic treatment, the ultrasonic duration for each time is 0-10 s, and the time interval between two adjacent ultrasonic treatments is 0-10 s.

[0041] (4) While performing ultrasonic and stirring treatments, dropwise add the tourmaline particle suspension to the chitosan / polyvinyl alcohol solution, and then continue ultrasonic and stirring treatments to uniformly disperse the tourmaline particles to obtain a tourmaline / chitosan / polyvinyl alcohol mixture;

[0042] Preferably, in step (4), the ultrasonic process is intermittent ultrasonic treatment for 30-60 min at a frequency of 10-100 kHz (preferably 20-25 kHz) and a power of 20-2000 W (preferably 50-250 W), and continuous magnetic stirring is performed while ultrasonicating; during the intermittent ultrasonic treatment, the ultrasonic duration for each time is 0-10 s, and the time interval between two adjacent ultrasonic treatments is 0-10 s.

[0043] (5) Freeze the tourmaline / chitosan / polyvinyl alcohol mixture and then thaw it to complete one freeze-thaw cycle; repeat the freeze-thaw cycle several times to obtain a composite;

[0044] Preferably, in step (5), the tourmaline / chitosan / polyvinyl alcohol mixture is frozen in an environment of -15°C to -30°C (i.e., minus 15°C to minus 30°C) (preferably -20°C) for 20 to 24 hours, and then thawed at room temperature (i.e., 20 to 30°C) for 2 to 4 hours to complete one freeze-thaw cycle. The freeze-thaw cycle is repeated 3 to 5 times.

[0045] (6) Place the composite in absolute ethanol to dehydrate and dry the composite, and obtain the tourmaline / chitosan / polyvinyl alcohol composite hydrogel, i.e., the tourmaline particle composite hydrogel.

[0046] The present invention also provides a tourmaline particle composite hydrogel prepared by the above method.

[0047] The present invention also provides an application of the tourmaline particle composite hydrogel, characterized in that the tourmaline particle composite hydrogel is applied to wound dressings or artificial cartilage.

[0048] Performance test:

[0049] (1) Swelling property: Weigh the dried composite hydrogel (1×1×0.2 cm 3 ), and record it as W d . Immerse the composite hydrogel in a beaker containing PBS solution, and then place the beaker in an incubator at 37°C. After a specific time interval, use filter paper to absorb the residual PBS solution on the surface of the swollen composite hydrogel, and weigh it again and record it as Ws. The calculation formula for the swelling ratio (SR) of the composite hydrogel is as follows:

[0050]

[0051] Among them, W s is the wet weight of the composite hydrogel, and W d is the dry weight of the composite hydrogel. Each group of experiments is repeated 3 times, and the experimental results are the average value and standard deviation of the 3 measurements.

[0052] (2) Hemolysis property: Take an appropriate amount of anticoagulated rabbit blood and dilute it with PBS solution at a volume ratio of 4:5. First, immerse the composite hydrogel (0.001 g) in 10 mL of PBS solution, incubate it in an incubator at 37°C for 30 min, and set 10 mL of PBS solution without sample and 10 mL of deionized water as negative and positive controls respectively. Then, add 0.2 mL of diluted rabbit whole blood to the composite hydrogel, negative control group, and positive control group respectively, and place them in an incubator at 37°C for another 1 h. Finally, centrifuge all samples at 3000 r / min for 5 min, and measure the absorbance value of the supernatant at a wavelength of 545 nm. The calculation formula for the hemolysis rate (HR) of the composite hydrogel is as follows:

[0053]

[0054] Among them, the absorbance values of the composite hydrogel, negative control, and positive control are ABSsample, ABSnegative control, and ABSpositive control, respectively. Each experiment was repeated 6 times, and the experimental results are the average value and standard deviation of 6 measurements.

[0055] (3) In vitro coagulation performance: The in vitro coagulation performance was evaluated by the in vitro coagulation index (BCI). First, the composite hydrogel was dried at 37 °C for 5 min. Then, 100 μL of fresh rabbit whole blood containing anticoagulant was added to each composite dressing, 10 μL of 0.2 M CaCl2 solution was quickly added, and the mixture was incubated at 37 °C for 5 min. 100 μL of anticoagulated whole blood and 10 μL of 0.2 M CaCl2 solution were added to a glass beaker without the composite hydrogel as a negative control. After 5 min, without disturbing the coagulated blood, 25 mL of deionized water was slowly added dropwise to recover the uncoagulated red blood cells, and the mixture was incubated with shaking at 37 °C at 30 r / min for 10 min. Finally, the supernatant in the beaker was aspirated, and the absorbance of each composite hydrogel at a wavelength of 542 nm was measured. The calculation formula for the BCI of the composite hydrogel is as follows:

[0056]

[0057] Among them, I s is the absorbance of the composite hydrogel, and I c is the absorbance of the control group. Each experiment was repeated 6 times, and the experimental results are the average value and standard deviation of 6 measurements.

[0058] (4) Antibacterial performance: The optical density method was used to evaluate the antibacterial efficiency of the composite hydrogel against Escherichia coli and Staphylococcus aureus. The steps include: adding 100 mL of distilled water to 2.5 g of LB broth medium, mixing well, and then dispensing the liquid nutrient medium into conical flasks, followed by sterilization in a high-temperature and high-pressure steam sterilizer for 20 min and allowing it to stand to room temperature. The composite hydrogel was transferred to a sterile operating table for ultraviolet sterilization for 60 min, and the sterilized composite hydrogel (0.4 g) was placed into a bacterial culture tube. The bacterial solution was diluted to a concentration of 10 6 CFU / mL with LB liquid medium at pH = 7.2, and 4 mL of the diluted bacterial solution was aspirated and added to the bacterial culture tube. Three parallel samples were set for each group. All samples were placed on a constant temperature shaker and incubated at 37 °C and 120 r / min for 8 h. After 8 h, the absorbance at a wavelength of 600 nm was measured. The calculation formula for the antibacterial rate of the composite hydrogel is as follows:

[0059]

[0060] Among them, Ac is the absorbance of the bacterial suspension cultured without the composite hydrogel, and As is the absorbance of the bacterial suspension cultured with the composite hydrogel.

[0061] (5) Cytotoxicity: The composite hydrogel material was sterilized by ultraviolet irradiation for 30 min. The sterilized composite hydrogel was placed in DMEM culture medium and incubated in an incubator (37 °C, 5% CO2) for 24 h to prepare the original extract of the material. Subsequently, a certain volume of the original extract was diluted with DMEM culture medium to prepare an extraction dilution with a concentration of 50% of the original extract. The cultured L929 cells were inoculated into a 96-well culture plate at 3000 cells per well (100 μL / well, cell density of 1×10 5 / mL). The inoculated 96-well culture plate was placed in an incubator and cultured for another 24 h. After 24 h, the dilution in the culture medium was discarded, and after washing 3 times with PBS solution, 50% extraction dilution was used instead. Three parallel samples were set in each group, and the negative control group was DMEM culture medium. After replacement, the 96-well culture plate was cultured in an incubator for 24 h. After 24 h, 20 μL of MTT solution with a mass concentration of 0.5% was added to each well and cultured for another 4 h. After 4 h, the culture solution in each well was aspirated, each well was rinsed with PBS, 150 μL of DMSO solution was added, and the culture plate was shaken at room temperature for 10 min and then placed in a 37 °C incubator. After 15 min, it was taken out and the absorbance at a wavelength of 570 nm was measured.

[0062] Example 1

[0063] (1) 0.2 g of chitosan (molecular weight of 120×10 4 ) was added to a mixed solvent of 9.6 mL of deionized water and 0.4 mL of glacial acetic acid, and magnetically stirred at room temperature for 4 h to obtain a chitosan solution;

[0064] 1 g of polyvinyl alcohol and 10 mL of deionized water were mixed and magnetically stirred for 4 h under the condition of a 90 °C water bath to obtain a polyvinyl alcohol solution;

[0065] (2) The chitosan solution and the polyvinyl alcohol solution were mixed at a volume ratio of 1:1 and stirred at room temperature for 4 h to obtain a chitosan / polyvinyl alcohol solution;

[0066] (3) 0.06 g of tourmaline particles with a particle size of 50 nm was added to a mixed solvent of deionized water and glacial acetic acid, and ultrasonicated for 20 min at a frequency of 20 kHz, a power of 200 W, ultrasonicating for 2 s and intervals of 2 s to prepare a tourmaline particle suspension;

[0067] (4) Add the tourmaline particle suspension drop by drop into the chitosan / polyvinyl alcohol solution, and while dropping, perform ultrasonic treatment for 45 min with a frequency of 20 kHz, a power of 200 W, an ultrasonic time of 2 s, and an interval of 2 s, accompanied by magnetic stirring, to obtain a tourmaline / chitosan / polyvinyl alcohol mixture;

[0068] (5) Freeze the mixed solution at -20 °C for 22 h, and then thaw it at room temperature for 2 h to complete one freeze-thaw cycle; repeat the freeze-thaw cycle 3 times in total;

[0069] (6) Place the composite in absolute ethanol and dry it by dehydration with absolute ethanol to obtain a tourmaline / chitosan / polyvinyl alcohol composite hydrogel.

[0070] Comparative Example 1

[0071] (1) Add 0.2 g of chitosan (molecular weight of 120×10 4 ) to a mixed solvent of 9.6 mL of deionized water and 0.4 mL of glacial acetic acid, and magnetically stir at room temperature for 4 h to obtain a chitosan solution;

[0072] Mix 1 g of polyvinyl alcohol and 10 mL of deionized water, and magnetically stir at 90 °C in a water bath for 4 h to obtain a polyvinyl alcohol solution;

[0073] (2) Mix the chitosan solution and the polyvinyl alcohol solution in a volume ratio of 1:1 and stir at room temperature for 4 h to obtain a chitosan / polyvinyl alcohol solution;

[0074] (3) Freeze the chitosan / polyvinyl alcohol solution at -20 °C for 22 h, and then thaw it at room temperature for 2 h to complete one freeze-thaw cycle; repeat the freeze-thaw cycle 3 times in total;

[0075] (5) Place the composite in absolute ethanol and dry it by dehydration with absolute ethanol to obtain a chitosan / polyvinyl alcohol hydrogel.

[0076] The antibacterial rate measurement results of the hydrogel are shown in Table 1:

[0077] Table 1

[0078] Sample Antibacterial rate against Escherichia coli (%) Antibacterial rate against Staphylococcus aureus (%) Example 1 90.02±1.16％ 76.25±5.37％ Comparative Example 1 85.26±0.99％ 63.88±7.57％

[0079] The cell viability measurement results of the hydrogel are shown in Table 2:

[0080] Table 2

[0081] Sample Cell viability rate (%) Example 1 92.03±1.09％ Comparative Example 1 93.21±1.14％

[0082] According to the cytotoxicity results, the biosafety levels of Example 1 and Comparative Example 1 are both Class I, belonging to the category of slight toxicity, and can be used as wound dressings.

[0083] As can be seen from Table 1 and Table 2, compared with Comparative Example 1, the introduction of tourmaline particles in Example 1 improved the in vitro coagulation and antibacterial abilities of the hydrogel, reducing the in vitro coagulation index of the hydrogel by 66.33%, and increasing the antibacterial rates against Escherichia coli and Staphylococcus aureus by 4.76% and 16.22% respectively.

[0084] Example 2

[0085] (1) Add 0.1 g of chitosan (molecular weight of 120×10 4 ) to a mixed solvent of 9.6 mL of deionized water and 0.4 mL of glacial acetic acid, and magnetically stir for 4 h at room temperature to obtain a chitosan solution;

[0086] Mix 1.4 g of polyvinyl alcohol and 10 mL of deionized water, and magnetically stir for 4 h under the condition of a 90°C water bath to obtain a polyvinyl alcohol solution;

[0087] (2) Mix the chitosan solution and the polyvinyl alcohol solution at a volume ratio of 1:1, and stir at room temperature for 4 h to obtain a chitosan / polyvinyl alcohol solution;

[0088] (3) Add 0.09 g of tourmaline particles with a particle size of 100 nm to a mixed solvent of deionized water and glacial acetic acid, and ultrasonicate for 20 min at a frequency of 20 kHz, a power of 200 W, ultrasonic for 2 s, and interval of 2 s to prepare a tourmaline particle suspension;

[0089] (4) Gradually add the tourmaline particle suspension dropwise to the chitosan / polyvinyl alcohol solution, and ultrasonicate for 45 min at a frequency of 20 kHz, a power of 200 W, ultrasonic for 2 s, and interval of 2 s while stirring magnetically during the dropping to obtain a tourmaline / chitosan / polyvinyl alcohol mixture;

[0090] (5) Freeze the mixed solution at -20°C for 22 h, and then thaw at room temperature for 2 h to complete one freeze-thaw cycle; Repeat the freeze-thaw cycle 3 times in total;

[0091] (6) Place the composite in absolute ethanol and dry it by dehydration with absolute ethanol to obtain a tourmaline / chitosan / polyvinyl alcohol composite hydrogel.

[0092] Example 3

[0093] (1) Add 0.15 g of chitosan (molecular weight of 120×10 4 ) to a mixed solvent of 9.6 mL of deionized water and 0.4 mL of glacial acetic acid, and magnetically stir for 4 h at room temperature to obtain a chitosan solution;

[0094] Mix 1.05 g of polyvinyl alcohol and 10 mL of deionized water, and magnetically stir for 4 h under the condition of an 85°C water bath to obtain a polyvinyl alcohol solution;

[0095] (2) Mix the chitosan solution and the polyvinyl alcohol solution in a volume ratio of 1:1 and stir at room temperature for 4 h to obtain a chitosan / polyvinyl alcohol solution;

[0096] (3) Add 0.084 g of tourmaline particles with a particle size of 80 nm to a mixed solvent of deionized water and glacial acetic acid, and ultrasonicate for 30 min at a frequency of 20 kHz, a power of 200 W, ultrasonication for 2 s, and an interval of 2 s to prepare a tourmaline particle suspension;

[0097] (4) Dropwise add the tourmaline particle suspension to the chitosan / polyvinyl alcohol solution, and ultrasonicate for 45 min at a frequency of 20 kHz, a power of 200 W, ultrasonication for 2 s, and an interval of 2 s while stirring magnetically to obtain a tourmaline / chitosan / polyvinyl alcohol mixture;

[0098] (5) Freeze the mixed solution at -22 °C for 22 h and then thaw at room temperature for 2 h to complete one freeze-thaw cycle; Repeat the freeze-thaw cycle 3 times in total;

[0099] (6) Place the composite in absolute ethanol and dry it by dehydration with absolute ethanol to obtain a tourmaline / chitosan / polyvinyl alcohol composite hydrogel.

[0100] It can be seen from Figures 1-4 that the introduction of tourmaline particles increases the number of pores, the pore size and the distribution uniformity on the surfaces of the three composite hydrogels in Example 1, Example 2 and Example 3. Among them, the three-dimensional network structure of the composite hydrogel in Example 1 is more regular and better meets the requirements of wound dressings (as Figure 1 shown). The surface of the hydrogel in Comparative Example 1 is mainly composed of small pores, with a small number and uneven distribution (as Figure 4 shown).

[0101] The swelling results of the hydrogel after reaching equilibrium in PBS solution are shown in Table 3:

[0102] Table 3

[0103] Sample Swelling ratio Example 1 181％ Example 2 150％ Example 3 167％ Comparative Example 1 136％

[0104] It can be seen from Figure 5As can be seen from Table 3, within the first 3 h, the hydrogel rapidly absorbed the PBS solution, and the swelling rate increased relatively quickly. As time extended, the swelling rate of the hydrogel grew slower and slower, and finally the hydrogel reached swelling equilibrium at about 6 h. The swelling rate of the composite hydrogel of Example 1 after reaching equilibrium in the PBS solution was 181%, the swelling rate of the composite hydrogel of Example 2 after reaching equilibrium in the PBS solution was 150%, the swelling rate of the composite hydrogel of Example 3 after reaching equilibrium in the PBS solution was 167%, while the swelling rate of the composite hydrogel of Comparative Example 1 after reaching equilibrium in the PBS solution was only 136%.

[0105] The hemolysis rate measurement results of the hydrogel are shown in Table 4 as follows:

[0106] Table 4

[0107] Sample Hemolysis rate Example 1 1.29±0.08％ Example 2 2.20±0.18％ Example 3 1.57±0.12％ Comparative Example 1 2.31±0.18％

[0108] As can be seen from Table 4, the hemolysis rates of the hydrogels were all less than 5%, meeting the standard requirements of the hemolysis rate.

[0109] The BCI results of the hydrogel are shown in Table 5 as follows:

[0110] Table 5

[0111] Sample BCI Example 1 22.79±1.72％ Example 2 40.15±2.11％ Example 3 31.37±1.12％ Comparative Example 1 67.69±1.80％

[0112] As can be seen from Table 5, the lower the BCI of the material, the better the in vitro blood coagulation effect of the material. Compared with Comparative Example 1, the introduction of tourmaline particles decreased the BCI indexes of Example 1, Example 2 and Example 3, indicating that the introduction of tourmaline particles improved the in vitro blood coagulation performance of the composite hydrogel. The introduction of tourmaline particles improved the swelling performance of the composite hydrogel. Materials with good swelling performance can rapidly absorb the liquid components in blood and promote the aggregation of red blood cells and platelets. In addition, due to its spontaneous polarization effect, tourmaline particles will generate a certain amount of negative charges. When blood contacts negatively charged tourmaline after leaving the body, it can effectively activate Factor XII to participate in the endogenous blood coagulation reaction to promote blood coagulation. Under the combined action of rapid liquid absorption and charge stimulation, the hemostasis efficiency of the material is significantly improved.

[0113] Matters not described in the present invention are applicable to the prior art.

Claims

1. A preparation method of tourmaline particle composite hydrogel, characterized in that, The method comprises the following steps: (1) Prepare a chitosan solution and a polyvinyl alcohol solution; (2) Mix the chitosan solution and the polyvinyl alcohol solution and stir evenly to obtain a chitosan / polyvinyl alcohol solution; (3) Add tourmaline particles into a mixed solvent of deionized water and glacial acetic acid, and subject to ultrasonic treatment to uniformly disperse the tourmaline particles in the mixed solvent to prepare a tourmaline particle suspension; The ultrasonic process is intermittent ultrasonic treatment for 15 - 35 min at a frequency of 10 - 100 kHz and a power of 20 - 2000 W; during the intermittent ultrasonic treatment, the ultrasonic duration for each time is 0 - 10 s, and the time interval between two adjacent ultrasonic treatments is 0 - 10 s; The mass of the tourmaline particles is 1 - 20% of the sum of the masses of chitosan and polyvinyl alcohol; (4) While performing ultrasonic and stirring treatments, dropwise add the tourmaline particle suspension into the chitosan / polyvinyl alcohol solution, and then continue ultrasonic and stirring treatments to uniformly disperse the tourmaline particles to obtain a tourmaline / chitosan / polyvinyl alcohol mixture; The ultrasonic process is intermittent ultrasonic treatment for 30 - 60 min at a frequency of 10 - 100 kHz and a power of 20 - 2000 W, and continuously magnetically stir while ultrasonicating; during the intermittent ultrasonic treatment, the ultrasonic duration for each time is 0 - 10 s, and the time interval between two adjacent ultrasonic treatments is 0 - 10 s; (5) Freeze the tourmaline / chitosan / polyvinyl alcohol mixture and then thaw it to complete one freeze - thaw cycle; repeat the freeze - thaw cycle several times to obtain a composite; (6) Place the composite in absolute ethanol and dehydrate and dry the composite to obtain a tourmaline particle - composite hydrogel.

2. The preparation method of tourmaline particle composite hydrogel according to claim 1, characterized in that, In step (1), dissolve chitosan in a mixed solvent of deionized water and glacial acetic acid, and stir evenly to obtain a chitosan solution; mix polyvinyl alcohol and deionized water and stir evenly to obtain a polyvinyl alcohol solution; The concentration of the chitosan solution is 0.01 - 0.05 g / mL, the temperature for preparing the chitosan solution is 20 - 30 °C, and the stirring time is 4 - 6 h; the molecular weight of chitosan is 50 - 150×10 4 ; the volume ratio of deionized water to glacial acetic acid is 1 - 30:1 - 5; The concentration of the polyvinyl alcohol solution is 0.05 - 0.15 g / mL, the temperature for preparing the polyvinyl alcohol solution is 85 - 100 °C, and the stirring time is 4 - 6 h.

3. The preparation method of tourmaline particle composite hydrogel according to claim 1, characterized in that, In step (2), the volume ratio of the chitosan solution to the polyvinyl alcohol solution is 1 - 5:1 - 5, the temperature for preparing the chitosan / polyvinyl alcohol solution is 20 - 30 °C, and the stirring time is 4 - 6 h.

4. The preparation method of tourmaline particle composite hydrogel according to claim 1, characterized in that, In step (3), the particle size of the tourmaline particles is 10 nm - 5 μm.

5. The preparation method of tourmaline particle composite hydrogel according to claim 1, characterized in that, In step (5), freeze the tourmaline / chitosan / polyvinyl alcohol mixture in an environment of - 15 °C - 30 °C for 20 - 24 h, and then thaw it at 20 - 30 °C for 2 - 4 h to complete one freeze - thaw cycle; repeat the freeze - thaw cycle 3 - 5 times.

6. A tourmaline particle composite hydrogel prepared by any one of the methods according to claims 1 - 5.

7. An application of the tourmaline particle composite hydrogel according to claim 6, characterized in that, Application of the tourmaline particle - composite hydrogel in preparing wound dressings or preparing artificial cartilage.

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