Spunlaid fiber and method of making same

Abstract

The application relates to a spinning fiber and a preparation method thereof. The spinning fiber is prepared from raw materials including polyvinyl alcohol and chitosan in a mass ratio of (6-8):(2-4) through solution jet spinning of a mixed crosslinked product of the raw materials. The application provides a spinning fiber which is prepared from a mixed and crosslinked product of chitosan and polyvinyl alcohol in a specific mass ratio through solution jet spinning. The polyvinyl alcohol has better hydrophilicity than the chitosan, and the chitosan has a network structure after interpenetration and crosslinking with the polyvinyl alcohol, so that the hydrophilicity of the chitosan is improved, the swelling degree is increased, the hemostatic effect is better, the effusion of a wound can be effectively absorbed, the wound can be dried, and bacterial reproduction can be prevented.

Description

Technical Field

[0001] This application relates to the field of medical device technology, and in particular to a spun fiber and a method for preparing the same. Background Technology

[0002] Nosebleeds are a common clinical symptom that can be caused by nasal diseases or systemic diseases. They can manifest as unilateral or bilateral, intermittent, recurrent, or continuous bleeding, and in severe cases, can even lead to hemorrhagic shock and anemia. Clinically, for patients with acute nosebleeds involving significant bleeding, large areas of oozing, or unclear bleeding sites, local treatment with nasal hemostatic gauze is often performed.

[0003] Commonly used nasal gauze for hemostasis is a fibrous product made from chitosan through spinning. Chitosan enhances platelet adhesion and aggregation, promotes platelet thrombus formation, and thus accelerates the intrinsic coagulation process, making it widely used as a raw material in hemostatic products. Chitosan also possesses good bioactivity, biocompatibility, and biodegradability, and has special functions such as antibacterial, antiseptic, and wound-healing promotion, attracting widespread attention in hemostatic products.

[0004] However, currently, hemostatic gauze made solely from chitosan maintains a relatively stable physical structure and chemical properties after contact with blood. Therefore, the hemostatic effect mainly occurs on the surface of the gauze fibers, and the interior of the gauze cannot directly participate in the hemostatic reaction, resulting in limited hemostatic efficacy. Summary of the Invention

[0005] Based on this, this application provides a spun fiber that is beneficial to improving hemostasis and a method for preparing the same.

[0006] In a first aspect, this application provides a spun fiber, the raw materials of which include polyvinyl alcohol and chitosan in a mass ratio of (6~8):(2~4);

[0007] The spun fibers are obtained by solution jet spinning of the mixed crosslinked products of the raw materials.

[0008] In some embodiments, the mass ratio of polyvinyl alcohol to chitosan is (6~8):(2~4).

[0009] In some embodiments, the degree of deacetylation of the chitosan is 80.0% to 95.0%.

[0010] In some embodiments, the degree of polymerization of the polyvinyl alcohol is 1750±50, and the degree of hydrolysis is ≥99.0%.

[0011] Secondly, this application also provides a method for preparing spun fibers as described in any embodiment of the first aspect above, comprising the following steps:

[0012] The chitosan is dissolved in an acidic solution to form a solution containing chitosan;

[0013] The chitosan-containing solution is mixed with polyvinyl alcohol, and the chitosan and polyvinyl alcohol are crosslinked to form a solution containing the mixed crosslinked product;

[0014] The spun fibers are prepared by solution jet spinning of the solution containing the mixed crosslinking products under a pressure of 0.2 MPa to 0.55 MPa.

[0015] In some embodiments, the step of forming the solution containing the mixed crosslinking product includes:

[0016] The polyvinyl alcohol is dissolved in water to form a solution containing polyvinyl alcohol;

[0017] The chitosan-containing solution and the polyvinyl alcohol-containing solution are mixed to crosslink the chitosan and polyvinyl alcohol, forming the solution containing the mixed crosslinking product.

[0018] In some embodiments, the conditions for forming the chitosan-containing solution satisfy at least one of the following conditions:

[0019] (1) The acidic solution contains acetic acid with a mass fraction of 50% to 70%;

[0020] (2) The dissolution temperature is 40℃~60℃;

[0021] (3) During the dissolution process, the pH should be controlled to be <6;

[0022] (4) The concentration of chitosan in the chitosan-containing solution is 1 g / mL to 3 g / mL.

[0023] In some embodiments, the conditions for forming the polyvinyl alcohol-containing solution satisfy at least one of the following conditions:

[0024] (1) The polyvinyl alcohol dissolves in water at a temperature of 80℃~96℃;

[0025] (2) The concentration of polyvinyl alcohol in the polyvinyl alcohol-containing solution is 10 g / mL to 15 g / mL.

[0026] In some embodiments, the concentration of the mixed crosslinking product in the solution is 6.4 g / mL to 12.6 g / mL.

[0027] In some embodiments, the solution jet spinning conditions satisfy at least one of the following conditions:

[0028] (1) The feeding rate is 7 mL / h to 60 mL / h;

[0029] (2) The distance between the spinning needle and the collector is 20cm~60cm;

[0030] (3) The relative humidity of the spinning environment is 40%~60%.

[0031] Thirdly, this application also provides the application of the spinning fibers described in any of the embodiments of the first aspect above in the preparation of hemostatic products.

[0032] This application provides a spun fiber obtained by solution-jet spinning a product of chitosan and polyvinyl alcohol in a specific mass ratio as raw materials, after mixing and cross-linking the two. Chitosan has biological activities such as accelerating platelet adhesion, aggregation, and activating coagulation cascade reactions. Polyvinyl alcohol has better hydrophilicity than chitosan. When mixed with chitosan and solution-jet spun, the two materials can interpenetrate and cross-link to form a stable three-dimensional network structure, thereby improving the hydrophilicity of chitosan, increasing its swelling degree, improving its hemostatic effect, and effectively absorbing wound fluid, which is beneficial for wound drying and preventing bacterial growth. Detailed Implementation

[0033] To facilitate understanding of this application, a more comprehensive description of the application will be provided below with reference to embodiments. However, this application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the disclosure of this application.

[0034] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0035] In this application, the technical features described in an open-ended manner include both closed technical solutions consisting of the listed features and open technical solutions that include the listed features.

[0036] The terms “first,” “second,” “third,” “fourth,” etc. (if present), as used in this application, are used to distinguish similar objects and are for descriptive purposes only. They are not necessarily used to describe a specific order or sequence, and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as “first” or “second” may explicitly or implicitly include at least one of that feature. In the description of this application, “multiple” means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0037] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0038] In this application, terms such as "preferred," "better," "more suitable," and "ideal" are used only to describe implementation methods or embodiments with better effects, and should be understood not to limit the scope of protection of this application.

[0039] In this application, terms such as "further," "even more," and "particularly" are used for descriptive purposes to indicate differences in content, but should not be construed as limiting the scope of protection of this application.

[0040] In this application, the terms "optionally," "optionally," and "optional" refer to options that are optional, meaning they are selected from either "with" or "without." If multiple "options" appear in a technical solution, unless otherwise specified and there are no contradictions or mutual constraints, each "option" is independent.

[0041] In this application, numerical intervals (i.e., numerical ranges) are involved. Unless otherwise specified, optional numerical distributions within the aforementioned numerical intervals are considered continuous and include the two endpoints of the numerical range (i.e., the minimum and maximum values), as well as every value between these two endpoints. Furthermore, when multiple ranges are provided to describe features or characteristics, these ranges may be merged. In other words, unless otherwise specified, the ranges disclosed herein should be understood to include any and all subranges to which they are included.

[0042] In a first aspect, this application provides a spun fiber, the raw materials of which include polyvinyl alcohol and chitosan in a mass ratio of (6~8):(2~4);

[0043] Fibers are obtained by solution jet spinning of the mixed cross-linked products of raw materials.

[0044] This application provides a spun fiber obtained by solution-jet spinning a product of chitosan and polyvinyl alcohol in a specific mass ratio as raw materials. Chitosan possesses biological activities such as accelerating platelet adhesion, aggregation, and activating coagulation cascade reactions. Polyvinyl alcohol has better hydrophilicity, mechanical strength, and flexibility than chitosan. When mixed with chitosan, the two components first crosslink through hydrogen bonds and covalent bonds. After solution-jet spinning, the mixed solution containing chitosan and polyvinyl alcohol is stretched into nanofibers under the action of a high-speed airflow. During solvent evaporation, chitosan and polyvinyl alcohol self-assemble into a stable three-dimensional network structure, thereby improving the hydrophilicity and swelling degree of chitosan. The spun fiber obtained after solution-jet spinning has a better hemostatic effect and can effectively absorb wound fluid, which is beneficial for wound drying and prevents bacterial growth. It is more suitable for use as a hemostatic product, such as hemostatic gauze, and is suitable for hemostasis in the nasal cavity or other bleeding sites.

[0045] In some embodiments, the mass ratio of polyvinyl alcohol (PVA) to chitosan is (6-8):(2-4). If the chitosan content is too low, the hemostatic effect is weakened, and the coagulation mechanism may not be effectively activated, resulting in decreased hemostatic efficacy. Conversely, if the PVA content is too high, it may lead to excessive swelling or increased adhesion, causing the gauze to swell excessively after absorbing moisture, making it difficult to remove and potentially causing excessive adhesion to wound tissue, which could lead to further wound damage during dressing changes. If the chitosan content is too high, the PVA content will decrease accordingly, reducing the gauze's flexibility and making the material too stiff, losing appropriate flexibility and breathability, which is detrimental to wound healing and dressing changes. Within the above mass ratio range, the resulting spun fibers have better hydrophilicity, can absorb more blood and wound fluid, have better hemostatic and antibacterial effects, and the overall performance and effectiveness of the gauze are better.

[0046] In some of these embodiments, the degree of deacetylation of chitosan is 80.0% to 95.0%.

[0047] In some of these embodiments, the degree of polymerization of polyvinyl alcohol is 1750±50, and the degree of alcoholysis is ≥99.0%.

[0048] The inventors discovered that electrospinning is currently the commonly used method for preparing spun fibers. However, electrospinning requires high pressure, which poses certain risks. Furthermore, the extrusion rate of the solution is slow during electrospinning, and the fiber formation rate is also slow due to the electric field, making it unsuitable for large-scale production. To overcome these process defects, the inventors further improved the preparation method.

[0049] Secondly, this application also provides a method for preparing spun fibers as described in any of the embodiments of the first aspect above, comprising the following steps:

[0050] Chitosan is dissolved in an acidic solution to form a solution containing chitosan;

[0051] A solution containing chitosan is mixed with polyvinyl alcohol, and the chitosan and polyvinyl alcohol are crosslinked to form a solution containing the mixed crosslinked product.

[0052] Solution jet spinning of a solution containing mixed crosslinking products was performed under pressure of 0.2 MPa to 0.55 MPa to prepare spun fibers.

[0053] Solution jet spinning refers to the process of using a high-speed airflow to stretch a solution containing mixed cross-linked products along the airflow direction. The solution enters the inner cavity of the spinneret, and the outer cavity provides a high-speed airflow along the direction of the inner cavity needle tip, concentrating the solution into a thin liquid jet, which is then ejected and solidified to form solid fibers. As the solvent evaporates, dry fibers are formed.

[0054] Solution jet spinning utilizes a high-speed airflow to stretch and solidify a solution containing mixed cross-linked products. It offers high spinning speeds and yields, meeting the needs of large-scale production. The solution jet spinning process does not require high voltage, avoiding safety issues caused by static electricity. Furthermore, solution jet spinning has fewer process requirements and variables, allowing the use of various solution systems and collectors with no conductivity requirements.

[0055] In this application, solution jet spinning is used instead of the traditional electrospinning process to prepare spun fibers. Compared with the electrostatic method, solution jet spinning is simpler, does not require high pressure, is safer to operate, and has a fast spinning rate. It can quickly and in large quantities produce spun fibers composed of chitosan-polyvinyl alcohol nanofibers, resulting in fiber materials with good performance and low production costs.

[0056] In some embodiments, the step of forming a solution containing the mixed crosslinking products includes:

[0057] Polyvinyl alcohol is dissolved in water to form a solution containing polyvinyl alcohol;

[0058] A solution containing chitosan and a solution containing polyvinyl alcohol are mixed to crosslink the chitosan and polyvinyl alcohol, forming a solution containing the mixed crosslinked product.

[0059] Dissolving polyvinyl alcohol in water before mixing it with chitosan can improve the dissolution rate and make the mixture more uniform.

[0060] In some embodiments, the acidic solution used in forming the chitosan-containing solution contains 50% to 70% acetic acid by mass.

[0061] In some embodiments, the dissolution temperature during the formation of the chitosan-containing solution is 40°C to 60°C. Under these temperature conditions, chitosan can be completely dissolved in acetic acid.

[0062] In some embodiments, during the formation of the chitosan-containing solution, the pH is controlled to be less than 6. This pH condition is beneficial for improving the solubility of chitosan and for the reaction between chitosan and acetic acid.

[0063] In some embodiments, the concentration of chitosan in the chitosan-containing solution is 1 g / mL to 3 g / mL.

[0064] In some embodiments, the temperature at which polyvinyl alcohol dissolves in water is 80°C to 96°C. Under these temperature conditions, polyvinyl alcohol can be fully dissolved.

[0065] In some embodiments, the concentration of polyvinyl alcohol in the polyvinyl alcohol-containing solution is 10 g / mL to 15 g / mL.

[0066] In some embodiments, the concentration of the mixed crosslinking product in the solution is 6.4 g / mL to 12.6 g / mL. Under these conditions, it is beneficial to improve the film-forming effect of the spun fibers and enhance the fiber morphology.

[0067] In some embodiments, the feed rate for solution jet spinning is 7 mL / h to 60 mL / h. Controlling a suitable feed rate is beneficial for forming nanospun fibers.

[0068] In some embodiments, the distance between the spinning needle and the collector is 20cm to 60cm. Within this range, it is beneficial to collect the formed spun fibers.

[0069] In some embodiments, the spinning environment temperature is room temperature.

[0070] In some embodiments, the relative humidity of the spinning environment is 40% to 60%.

[0071] In some embodiments, the solution jet spinning equipment for solution jet spinning includes a spinneret and a dispensing needle. The spinneret includes an inner cavity and an outer cavity. The mixed solution flows in the inner cavity, and the high-speed airflow formed by compressed air passes through the outer cavity. The feed end of the dispensing needle is located in the inner cavity, and the tip of the dispensing needle passes through the center of the outer cavity and extends out of the outer cavity. The mixed solution enters the dispensing needle and is concentrated into a thin liquid jet, which is then ejected to form spun fibers.

[0072] Furthermore, the solution jet spinning equipment for solution jet spinning also includes a Bunsen lamp, which is placed below the spinneret. The exhaust port and gas flow rate of the Bunsen lamp are adjusted to obtain the coldest output flame, with a flame color of yellow-orange. This can increase the temperature of the high-speed airflow exiting the spinneret, bringing it to the temperature of the fiber formation point, thus facilitating the solidification and fiber formation.

[0073] Thirdly, this application also provides the application of the spinning fibers in any of the embodiments of the first aspect above in the preparation of hemostatic products.

[0074] Understandably, hemostatic products, such as hemostatic gauze, can be used to stop bleeding in the nasal cavity or other areas.

[0075] The following are specific examples.

[0076] Polyvinyl alcohol: purchased from China National Pharmaceutical Group Shanghai Chemical Reagent Co., Ltd., degree of polymerization 1750, degree of alcoholysis ≥99.0%.

[0077] Chitosan: Purchased from China National Pharmaceutical Group Shanghai Chemical Reagent Co., Ltd., with a degree of deacetylation of 90.0%.

[0078] All water used is double-distilled water.

[0079] Example 1

[0080] A method for preparing spun fibers includes the following steps:

[0081] Step 1: Weigh 0.4g of chitosan and place it in a clean beaker. Add 60% acetic acid solution and stir until homogeneous. During the stirring process, control the solution temperature at 50℃ and maintain the pH < 6 to obtain a chitosan-containing solution for later use. The concentration of chitosan in the chitosan-containing solution is 2g / mL.

[0082] Step 2: Weigh 2.0g of polyvinyl alcohol and dissolve it in distilled water at 90℃. Stir for 3 hours to ensure that it dissolves until there are no visible transparent polyvinyl alcohol particles, and obtain a polyvinyl alcohol-containing solution for later use. The concentration of polyvinyl alcohol in the polyvinyl alcohol-containing solution is 10g / mL.

[0083] Step 3: Slowly add the polyvinyl alcohol-containing solution obtained in Step 2 to the chitosan-containing solution obtained in Step 1, and magnetically stir for 0.5 hours to allow the polyvinyl alcohol and chitosan to crosslink. During stirring, the system temperature is controlled at 80℃ to form a homogeneous solution containing the mixed crosslinking products. The mass ratio of polyvinyl alcohol to chitosan is 8:2, and the concentration of the mixed crosslinking products in the solution is 8.4 g / mL.

[0084] Step 4: The solution containing the mixed cross-linked products obtained in Step 3 is subjected to solution jet spinning. The solution jet spinning equipment includes a spinneret, a dispensing needle, and a Bunsen burner. The spinneret includes an inner cavity and an outer cavity. The solution containing the mixed cross-linked products flows in the inner cavity, while a high-speed airflow formed by compressed air passes through the outer cavity. The feed end of the dispensing needle is located in the inner cavity, and the nozzle tip passes through the center of the outer cavity and extends out. The solution containing the mixed cross-linked products enters the dispensing needle and is concentrated into a thin liquid jet, which is then ejected to form spun fibers. The feed rate of the solution containing the mixed cross-linked products is 16 mL / h, and the pressurized air pressure provided in the outer cavity is 0.5 MPa. The Bunsen burner is placed below the spinneret. The exhaust port and gas flow rate of the Bunsen burner are adjusted to obtain the coldest output flame, with a flame color of yellow-orange, so that the temperature near the air outlet of the spinneret reaches the temperature of the fiber formation point. Solution jet spinning is carried out under an environmental condition of 55% relative humidity.

[0085] The solution sprayed from the dispensing needle evaporates to form spun fibers, which are deposited on a porous collector 60 cm away from the dispensing needle to form a fiber pad. The fiber pad is collected to obtain spun fibers.

[0086] Example 2

[0087] A method for preparing spun fibers includes the following steps:

[0088] Step 1: Same as Step 1 in Example 1.

[0089] Step 2: Same as Step 2 in Example 1.

[0090] Step 3: This step is largely the same as step 3 in Example 1, except that the mass ratio of polyvinyl alcohol to chitosan is 7:3, and the concentration of the mixed crosslinking product in the solution is 7.6 g / mL.

[0091] Step four: Same as step four in Example 1.

[0092] Example 3

[0093] A method for preparing spun fibers includes the following steps:

[0094] Step 1: Same as Step 1 in Example 1.

[0095] Step 2: Same as Step 2 in Example 1.

[0096] Step 3: This is largely the same as Step 3 in Example 1, except that the mass ratio of polyvinyl alcohol to chitosan is 6:4, and the concentration of the mixed crosslinking product in the solution is 6.8 g / mL.

[0097] Step four: Same as step four in Example 1.

[0098] Comparative Example 1

[0099] A method for preparing spun fibers includes the following steps:

[0100] Step 1: Same as Step 1 in Example 1.

[0101] Step 2: This is largely the same as Step 2 in Example 1, except that the concentration of polyvinyl alcohol in the solution is 6 g / mL.

[0102] Step 3: This is largely the same as Step 3 in Example 1, except that the mass ratio of polyvinyl alcohol to chitosan is 5:5, and the concentration of the mixed crosslinking product in the solution is 4 g / mL.

[0103] Step four: Same as step four in Example 1.

[0104] Comparative Example 2

[0105] A method for preparing spun fibers includes the following steps:

[0106] Step 1: Same as Step 1 in Example 1.

[0107] Step 2: Same as Step 2 in Example 1.

[0108] Step 3: This is largely the same as Step 3 in Example 1, except that the mass ratio of polyvinyl alcohol to chitosan is 4:6, and the concentration of the mixed crosslinking product in the solution is 5.2 g / mL.

[0109] Step four: Same as step four in Example 1.

[0110] Comparative Example 3

[0111] A method for preparing spun fibers includes the following steps:

[0112] Step 1: Same as Step 1 in Example 1.

[0113] Step 2: Same as Step 2 in Example 1.

[0114] Step 3: Same as Step 3 in Example 1.

[0115] Step 4: This is roughly the same as Step 4 in Example 1, except that the pressurized air pressure provided in the external cavity is 0.7 MPa.

[0116] Comparative Example 4

[0117] A method for preparing spun fibers includes the following steps:

[0118] Step 1: Same as Step 1 in Example 1.

[0119] Step 2: Same as Step 2 in Example 1.

[0120] Step 3: Same as Step 3 in Example 1.

[0121] Step 4: This is largely the same as Step 4 in Example 1, except that no pressurized air is provided during the airflow spinning process.

[0122] Comparative Example 5

[0123] A method for preparing spun fibers includes the following steps:

[0124] Step 1: Weigh 2.0g of polyvinyl alcohol and dissolve it in distilled water at 90℃. Stir for 3 hours to ensure that it dissolves until there are no visible transparent polyvinyl alcohol particles, and obtain a polyvinyl alcohol-containing solution for later use. The concentration of polyvinyl alcohol in the polyvinyl alcohol-containing solution is 6g / mL.

[0125] Step 2: Same as step 4 in Example 1.

[0126] Comparative Example 6

[0127] A method for preparing spun fibers includes the following steps:

[0128] Step 1: Same as Step 1 in Example 1.

[0129] Step 2: Same as Step 2 in Example 1.

[0130] Step 3: Same as Step 3 in Example 1.

[0131] Step 4: Use electrospinning instead of air-jet spinning.

[0132] The spun fibers prepared in Examples 1 to 3 and Comparative Examples 1 to 6 were used as gauze for performance testing. The test results are shown in Table 1 below.

[0133] Table 1 Performance test results of spun fibers

[0134]

[0135] Where E = (excellent), G = (good), C = (common), and F = (flunk).

[0136] Absorbency rate refers to the water absorption capacity of gauze. Gauze has the property of absorbing water to absorb blood, which helps to stop bleeding and prevent infection. The higher the absorbency rate, the stronger the absorption capacity of the gauze, and the faster it can stop bleeding.

[0137] Elongation at break reflects the flexibility and durability of gauze. A higher elongation at break means that the gauze is softer and can better adapt to the shape and size of the wound.

[0138] Average fiber diameter: A fiber diameter that is too small or too large may reduce the strength and durability of the gauze. Currently, a fiber diameter of around 278 nm provides better hemostasis and comfort.

[0139] Judging the effectiveness of nasal hemostasis: 1. Elongation at break: a higher elongation at break means the gauze is softer. 2. Appropriate fiber diameter can improve the fit and comfort of the hemostatic gauze. Both of these can better adapt to the nasal cavity structure and reduce irritation and damage to the nasal mucosa.

[0140] In summary, it can be seen that the spun fibers prepared in Examples 1 to 3 have a better effect on nasal hemostasis when used as gauze.

[0141] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0142] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A spun fiber, characterized in that, The raw materials include polyvinyl alcohol and chitosan, and the spun fibers are obtained by solution jet spinning of the mixed crosslinking product of the raw materials; The mass ratio of polyvinyl alcohol to chitosan is (6~8):(2~4); The method for preparing the spun fibers includes the following steps: The polyvinyl alcohol is dissolved in water to form a polyvinyl alcohol-containing solution, wherein the concentration of polyvinyl alcohol in the polyvinyl alcohol-containing solution is 10 g / mL to 15 g / mL; The chitosan is dissolved in an acidic solution to form a chitosan-containing solution, wherein the concentration of chitosan in the chitosan-containing solution is 1 g / mL to 3 g / mL. The chitosan-containing solution and the polyvinyl alcohol-containing solution are mixed to crosslink the chitosan and polyvinyl alcohol, forming a solution containing a mixed crosslinking product, wherein the concentration of the mixed crosslinking product is 6.4 g / mL to 12.6 g / mL. The spun fibers are prepared by solution jet spinning of the solution containing the mixed crosslinking products under a pressure of 0.2 MPa to 0.55 MPa.

2. The spun fiber according to claim 1, characterized in that, The degree of deacetylation of the chitosan is 80.0%~95.0%.

3. The spun fiber according to claim 1, characterized in that, The degree of polymerization of the polyvinyl alcohol is 1750±50, and the degree of alcoholysis is ≥99.0%.

4. The spun fiber according to claim 1, characterized in that, The conditions for forming the chitosan-containing solution satisfy at least one of the following conditions: (1) The acidic solution contains acetic acid with a mass fraction of 50% to 70%; (2) The dissolution temperature is 40℃~60℃; (3) Control the pH to <6 during the dissolution process.

5. The spun fiber according to claim 1, characterized in that, The conditions for forming the polyvinyl alcohol-containing solution are as follows: the polyvinyl alcohol dissolves in water at a temperature of 80°C to 96°C.

6. The spun fiber according to any one of claims 1, 4, or 5, characterized in that, Solution jet spinning requires at least one of the following conditions to be met: (1) The feeding rate is 7 mL / h to 60 mL / h; (2) The distance between the spinning needle and the collector is 20cm~60cm; (3) The relative humidity of the spinning environment is 40%~60%.

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