Controllable degradation antibacterial filament fiber and preparation method thereof

Abstract

The invention discloses a controllable degradation antibacterial filament fiber and a preparation method thereof, a calcium alginate filament fiber is prepared by using a wet spinning technology, and the calcium alginate filament fiber is strongly modified by physical and chemical methods respectively. The chemical modification adopts a cross-linking agent for modification, and the physical modification adopts cellulose nanocrystal (CNC) as a reinforcing material. The tensile breaking strength is improved to 43.25 cN / dtex from 16.35 cN / dtex which is not modified, the tensile breaking strength is improved by 2.6 times, and the degradation period is prolonged to 7 days from 2 days. On the basis, berberine is introduced into the fiber, so that the mechanical enhancement effect can be further achieved by means of the electrostatic attraction effect between materials, the antibacterial performance is obtained, and the antibacterial rate can reach 95.28%.

Description

Technical Field

[0001] The present invention relates to the field of biomedical materials, and particularly to a controllable degradation antibacterial filament fiber and a preparation method thereof. Background Art

[0002] Degradable antibacterial fibers have extensive and important applications in the medical field. Due to their unique properties, such fibers exhibit significant advantages in medical scenarios. In the aspect of wound dressings, degradable antibacterial fibers can provide a good protective barrier for wounds. Their antibacterial properties can effectively inhibit the growth of bacteria at the wound site and reduce the risk of infection. In the field of surgical sutures, sutures made of controllable degradation antibacterial filament fibers can continuously exert antibacterial effects while performing the suture function, preventing postoperative incision infection. Moreover, after the wound heals to a certain extent, the suture will automatically degrade without the need for suture removal, which is more convenient and comfortable for patients and also reduces the workload of medical staff.

[0003] Berberine, a quaternary ammonium alkaloid isolated from the traditional Chinese medicine Coptis chinensis, has the molecular formula C 20 H 18 NO4 + and is the main active ingredient for the antibacterial effect of Coptis chinensis. Alginate, a natural polyuronic acid with the chemical formula (C6H8O6)n, is mainly commercially available in the form of sodium salt, with the molecular formula (C6H7O6Na)n. Sodium alginate, as a natural polymer polysaccharide material, has excellent biocompatibility and degradability and has broad application prospects in the fields of medicine, environmental protection, etc. However, its defects of too fast degradation rate and insufficient mechanical properties limit its application in most fields.

[0004] Therefore, how to effectively enhance the mechanical properties of alginate fibers and how to regulate their degradability have become the current research hotspots and difficulties. By methods such as chemical modification, physical modification, and biological modification, the mechanical properties of alginate fibers can be improved and their degradation rate can be regulated to achieve the effects meeting the requirements of the medical field. Therefore, future research needs to pay more attention to the innovation and optimization of modification methods to seek more efficient modification means. Summary of the Invention

[0005] As a natural polymer material, alginic acid (SA) fiber has good biocompatibility and degradability, and has important potential application value in the medical field. Due to the low mechanical properties and too fast degradation rate of alginic acid fiber, its development is restricted. The technical problem to be solved by the present invention is to provide a preparation method of a controllable degradation antibacterial filament fiber. The present invention uses wet spinning technology to prepare calcium alginate filament fiber, and respectively carries out strength modification and function enhancement on it by physical and chemical methods. The several factors affecting the strength in the present invention are: the drawing effect of the raw filament, adding CNC enhancer, crosslinking effect, and electrostatic effect of loading drugs. The strength improvement range after each enhancement treatment is different, between 11.8% and 28.0%, the degradation period is extended from 2 days to 7 days, and the antibacterial rate can reach 95.28%, meeting the performance requirements of antibacterial fibers in the medical field.

[0006] As one aspect of the present invention, the present invention provides a preparation method of a controllable degradation antibacterial filament fiber, comprising the following steps:

[0007] (1) Preparation of CaCl2 coagulation bath, that is: use 100 g of anhydrous calcium chloride (CaCl2) to prepare 2 L of 5% (wt) calcium chloride solution as the coagulation bath for wet spinning.

[0008] (2) Preparation of alginic acid spinning solution, that is: dissolve alginic acid powder in water to prepare 100 mL of alginic acid solution with a certain concentration, which is called the spinning solution.

[0009] (3) Preparation of calcium alginate (CA) fiber, that is: after the alginic acid spinning solution prepared in step (2) is left standing for defoaming, at room temperature, use wet spinning technology to uniformly extrude with a syringe in a 5% (wt) CaCl2 coagulation bath to form fibers, and perform drawing treatment to enhance its mechanical properties, orientation degree and crystallinity.

[0010] (4) Preparation of cellulose nanocrystals (CNC), using bacterial cellulose as the raw material (bacterial cellulose is purchased from Qihong Technology Co., Ltd.), and the preparation method is as follows: first carry out enzymatic hydrolysis: 1 wt% cellulase (based on the dry weight of bacterial cellulose) (cellulase is purchased from Shanghai Macklin Biochemical Co., Ltd.), enzymatic hydrolysis temperature: 45 °C; pH value 4.8 - 5.0; reaction time 18 h; stirring speed: 150 rpm; terminate the reaction: heat the enzymatic hydrolysis solution to 90 °C and keep it for 10 minutes to inactivate the enzyme, then cool it to room temperature, and centrifuge it to collect the precipitate. Then carry out acid hydrolysis: the precipitate collected by centrifugation is directly subjected to acid degradation, add it to a sulfuric acid solution with a volume concentration of 50% according to the mass ratio of solid to liquid of 1:10, and carry out acid hydrolysis at 35 °C for 2 h to obtain cellulose nanocrystals (CNC) with an aspect ratio > 200 and a length exceeding 10 μm.

[0011] At the same time, plant-derived CNCs were prepared using wheat straw as raw material using the same method for comparison of morphology and aspect ratio.

[0012] (5) Preparation of calcium alginate / nanocellulose (CA / CNC) composite fibers, i.e., using nanocellulose (CNC) to enhance and modify calcium alginate fibers, specifically, taking 1-2 g of nanocellulose (CNC) and dispersing it in 5 mL of deionized water to obtain a nanocellulose (CNC) dispersion, then mixing the dispersion with the alginate solution prepared in step (2) and stirring evenly on a magnetic stirrer to obtain a CA / CNC spinning solution, and using the method in step (3) to coagulate in a 5% (wt) CaCl2 coagulation bath to form solid fibers, and after slow uniform drawing and water washing, obtaining CA / CNC composite fibers.

[0013] (6) Comparative sample: Preparation of calcium alginate / microcrystalline cellulose (CA / MCC) composite fibers, i.e., using microcrystalline cellulose (MCC) of the same mass as the nanocellulose CNC in step (5) to enhance and modify the calcium alginate fibers, and the specific method is the same as step (4).

[0014] (7) Preparation of calcium alginate / nanocellulose / berberine (CA / CNC / Ber) composite fibers, namely: 10 mL of 20% berberine hydrochloride (Ber) was uniformly dispersed in an ethanol / water mixed solution by means of a magnetic stirrer, and then a certain volume of the Ber was taken and mixed with the alginate solution prepared in step (2) and 5 g of the nanocellulose (CNC) dispersion prepared in step (5) and stirred on a magnetic stirrer. First, alginate anions were formed, and then reacted with the berberine quaternary ammonium alkaloid C 20 H 18 NO4 + Electrostatic attraction is formed, bonding occurs, and CA / CNC / Ber spinning solution is obtained. The method for preparing CA / CNC / Ber composite fibers is the same as step (5).

[0015] (8) Cross-linking treatment, i.e., cross-linking treatment of wet fibers using a cross-linking agent such as an amine cross-linking agent, an acid anhydride cross-linking agent, a polyol cross-linking agent, etc., and then taking out the fibers after cross-linking and washing them to obtain modified composite fibers.

[0016] The mass concentration of the alginate solution in step (2) is 4% to 6%, the dissolution temperature is 25° C., and the dissolution time is 12 hours.

[0017] In the step (3), the solidification time is 5 to 10 minutes, and the stretching multiple of the stretching treatment is 2 to 4 times.

[0018] In the step (5), the mass ratio of the dry weight of the nanocellulose CNC to the alginate solution used is 0.5 to 2:100.

[0019] In step (6), the mass ratio of the dry weight of microcrystalline cellulose MCC to the mass of the alginic acid solution used is 0.5-2:100.

[0020] In step (7), the absorption amount of the berberine ethanol aqueous solution is 2-5 mL.

[0021] In step (7), the stirring time of berberine and the alginic acid solution is 10-30 min, that is, the electrostatic binding time is 10-30 min.

[0022] In step (8), the crosslinking agent can be selected from any one of crosslinking agents such as amine crosslinking agents, acid anhydride crosslinking agents, polyol crosslinking agents, etc. For example, a 5% (wt) GA solution obtained by diluting a 25% glutaraldehyde (GA) solution by 5 times is used as the crosslinking agent. Then, the wet fibers prepared in steps (3), (4), (5), and (6) are respectively soaked in the crosslinking agent solution for 30 min, 60 min, and 90 min, and then taken out after crosslinking to obtain each modified composite fiber.

[0023] The performance test method includes: mechanical property test, morphological characterization, moisture absorption and swelling rate, degradation period analysis, and antibacterial rate test.

[0024] Beneficial effects

[0025] Due to the adoption of the above technical solutions, compared with the prior art, the present invention has the following advantages and positive effects:

[0026] The beneficial effects of the present invention:

[0027] (1) Physical stretching, CNC nanomaterials, and chemical crosslinking can all greatly enhance the mechanical strength of alginic acid filament fibers. The three modification methods of physical stretching enhancement modification, CNC nanomaterial enhanced physical modification, and chemical crosslinking modification can all enhance the strength of calcium alginate filament fibers to different degrees. The breaking strength of the CA / CNC fiber obtained after enhancement modification is increased from 16.35 cN / dtex to 36.42 cN / dtex. Among them, the mass ratio of the dry weight of the best nanocellulose CNC to the mass of the alginic acid solution used is 1.5:100, the concentration of the glutaraldehyde crosslinking agent is the best 5% (wt), and the best crosslinking duration is 30 min.

[0028] (2) After introducing the drug berberine, the mechanical strength of the alginic acid filament fiber can be further enhanced. Berberine quaternary alkaloid C 20 H 18 NO4 +Form an electrostatic attraction with the alginate anion. This chemical force binding leads to a further enhancement of the mechanical strength, which is increased from 36.42 cN / dtex to 43.35 cN / dtex. Among them, the absorption amount of 20% berberine ethanol / aqueous solution is 2 - 5 mL, and its volume ratio in the 5% alginate solution is 2% - 5%.

[0029] (3) The hygroscopic swelling rate and degradation period of the alginate filament fiber are better. As a medical fiber, such as surgical sutures, an appropriate hygroscopic swelling rate and degradation period are required. The CA / CNC filament fiber has the best hygroscopicity, reaching a moisture absorption rate of 170%. The degradation period is extended from 2 days to 7 days. This performance is more suitable for wound healing.

[0030] (4) The antibacterial property of the alginate filament fiber is greatly improved. The calcium alginate fiber itself, as a polysaccharide-based material, is prone to bacterial growth. After adding berberine, the drug-loaded CA / CNC / Ber composite fiber obtains antibacterial properties, and the antibacterial rate against Escherichia coli can reach 95.28%.

[0031] (5) During the preparation process of the alginate-based composite filament fiber, its mechanical strength is adjusted by the type and reaction duration of the cross-linking agent, the addition amount of nanocellulose, and the draw ratio of the fiber, while affecting its moisture absorption rate and degradation period; the drug release rate and antibacterial rate are regulated by controlling the type and dosage of the loaded drug; thus, the effect of controllably adjusting the properties of the filament fiber is achieved. Description of the Drawings

[0032] Figure 1 It is the transmission electron microscope image of the self-made bacterial cellulose CNC used in the present invention.

[0033] Figure 2 It is the scanning electron microscope image of the plant-derived CNC used for comparison with the bacterial cellulose CNC.

[0034] Figure 3 It is the scanning electron microscope image of the comparative sample microcrystalline cellulose MCC used in the present invention.

[0035] Figure 4 It is the physical image of the filament fiber in Example 1 of the present invention.

[0036] Figure 5 It is the scanning electron microscope image of the surface of the calcium alginate / nanocellulose (CA / CNC) filament fiber in Example 1 of the present invention, where a is after drawing and b is before drawing.

[0037] Figure 6 It is the test result of the strength performance of the raw filament and the drug-loaded filament fiber in Example 1 of the present invention.

[0038] Figure 7Schematic diagram of the binding force between sodium alginate and berberine hydrochloride molecules in the present invention.

[0039] Figure 8 Antibacterial performance test diagram of calcium alginate / nanocellulose / berberine (CA / CNC / Ber) filament fiber in Example 1 of the present invention, where (I) blank sample; (II) SA; (III) CA / CNC fiber; (IV) CA / CNC / Ber fiber; Escherichia coli was diluted to Detailed implementation manners

[0040] The present invention will be further described below in conjunction with specific embodiments. These embodiments are only for clearly disclosing the present invention, but the protection scope of the present invention is not limited thereto.

[0041] Example 1:

[0042] Step 1, Preparation of CaCl2 coagulation bath, that is: 100 g of anhydrous calcium chloride (CaCl2) was used to prepare 2 L of 5% (wt) calcium chloride solution as the coagulation bath for wet spinning.

[0043] Step 2, Preparation of sodium alginate spinning solution, that is: 5 g of sodium alginate powder was dissolved in 95 mL of water to prepare 100 g of sodium alginate spinning solution with a mass concentration of 5%, and the dissolution time was 16 h at room temperature.

[0044] Step 3, Preparation of calcium alginate (CA) fiber, that is: after the sodium alginate spinning solution prepared in step (2) was left standing for defoaming, at room temperature, it was uniformly extruded with a syringe in a 5% (wt) CaCl2 coagulation bath by wet spinning technology to form fibers, and the coagulation time was 10 min. In order to enhance its mechanical properties, stretching treatment was carried out, and the stretching ratio was 2 times.

[0045] Step 4, Using bacterial cellulose as the raw material (bacterial cellulose was purchased from Qihong Technology Co., Ltd.), the preparation method is as follows: First, enzymatic hydrolysis: 1 wt% cellulase (based on the dry weight of bacterial cellulose) (cellulase was purchased from Shanghai Macklin Biochemical Co., Ltd.), enzymatic hydrolysis temperature: 45 °C; pH value 4.8 - 5.0; reaction time 18 h; stirring speed: 150 rpm; termination of reaction: The enzymatic hydrolysis solution was heated to 90 °C and maintained for 10 minutes to inactivate the enzyme, and then cooled to room temperature, and the precipitate was collected by centrifugation. Then acid hydrolysis was carried out: The precipitate collected by centrifugation was directly subjected to acid degradation, and added to a 50% sulfuric acid aqueous solution with a volume concentration of 50% according to the mass ratio of solid to liquid of 1:10, and acid hydrolyzed at 35 °C for 2 h to obtain nanocellulose (CNC) with an aspect ratio > 200 and a length exceeding 10 μm, which was used for subsequent fiber-reinforced CNC, such as Figure 1As shown. Meanwhile, using wheat straw as raw material, plant-derived CNC was prepared by the same method for comparison of morphology and aspect ratio, as Figure 2 shown.

[0046] Step 5: Preparation of calcium alginate / nanocellulose (CA / CNC) composite fiber, that is, using nanocellulose (CNC) to enhance and modify calcium alginate fiber. The mass ratio of the dry weight of nanocellulose CNC to the mass of the used calcium alginate spinning solution is 1.5:100. The specific method is as follows: Take 1.5 g of nanocellulose (CNC) and disperse it in 5 mL of deionized water to obtain a nanocellulose (CNC) dispersion. Then mix the nanocellulose (CNC) dispersion with 100 g of the calcium alginate spinning solution prepared in Step 2 and stir evenly on a magnetic stirrer to obtain a CA / CNC spinning stock solution. Use the method in Step (3) to uniformly extrude and solidify in a 5% (wt) CaCl2 coagulation bath with a syringe to form solid fibers. After slowly and uniformly stretching by 2 times and washing with water, CA / CNC composite fibers are obtained.

[0047] Step 6: Preparation of the comparative sample - calcium alginate / microcrystalline cellulose (CA / MCC) composite fiber, that is, using 1.5 g of microcrystalline cellulose (MCC) with the same mass as CNC to enhance and modify calcium alginate fiber. MCC is purchased from Shanghai Macklin Biochemical Technology Co., Ltd. The morphology is as Figure 3 shown, and the fiber preparation method is the same as that in Step (5).

[0048] Step 7: Preparation of calcium alginate / nanocellulose / berberine (CA / CNC / Ber) composite fiber, that is, uniformly disperse berberine hydrochloride (Ber) in a 10 mL ethanol / water (volume ratio 1:1) mixed solution with the help of a magnetic stirrer. The mass fraction of berberine hydrochloride (Ber) is 20%. Then absorb 2 mL of it and mix it with 100 g of the calcium alginate solution prepared in Step (2) and 5 g of the nanocellulose (CNC) dispersion prepared in Step (5) respectively, and stir on a magnetic stirrer for 30 min. First, form alginate anions, and then combine with berberine quaternary alkaloid C 20 H 18 NO4 + to form an electrostatic attraction and combine to obtain a CA / CNC / Ber spinning stock solution. The method for preparing CA / CNC / Ber composite fiber is the same as that in Step (5): Use the method in Step (3) to uniformly extrude and solidify in a 5% (wt) CaCl2 coagulation bath with a syringe to form solid fibers. After slowly and uniformly stretching by 2 times and washing with water, CA / CNC / Ber composite fibers are obtained.

[0049] Step 8, Glutaraldehyde (GA) cross-linking treatment, that is: Dilute the 25% (wt) aqueous solution of glutaraldehyde (GA) 5 times with water to obtain a 5% (wt) GA solution as the cross-linking agent. Then, soak the wet fibers prepared in steps (3), (5), (6), and (7) in the cross-linking agent solution for 30 minutes respectively, take them out after cross-linking, and obtain the modified composite fibers. The average diameter of the composite fibers is 27 microns.

[0050] Step 9, Conduct fiber mechanical property tests, morphology characterization, moisture absorption and swelling rate, degradation cycle analysis, and antibacterial rate tests on the prepared CA filament fibers, CA / CNC filament fibers, CA / MCC filament fibers, and CA / CNC / Ber drug-loaded composite filaments respectively. The obtained fiber appearance is as Figure 4 shown, and the microscopic morphology on the fiber surface is as Figure 5 shown.

[0051] The three modification methods of physical tensile enhancement modification, CNC nanomaterial-enhanced physical modification, and chemical cross-linking modification can all enhance the strength of calcium alginate filament fibers to varying degrees. The strength improvement rates are shown in Table 1. The breaking strength of the CA / CNC fibers obtained after enhancement modification is increased from 16.35 cN / dtex of the unmodified fibers to 36.42 cN / dtex. On this basis, after introducing berberine into the fibers, the strength performance is further improved through the electrostatic binding force with alginic acid, as Figure 6 shown, and the tensile breaking strength is increased from 36.42 cN / dtex to 43.35 cN / dtex. The mechanism analysis is as Figure 7 shown. At the same time, the antibacterial performance test results are as Figure 8 shown, and the antibacterial rate can reach 95.28%. The degradation cycle is extended from 2 days to 7 days, solving the problem of too fast degradation rate in the past.

[0052] Table 1 Breaking strength and enhancement rate of different filament fibers

[0053]

[0054] Example 2:

[0055] Steps 1, 2, 3, and 4 are the same as those in Example 1.

[0056] In Step 5, calcium alginate / nanocellulose (CA / CNC) composite fibers were prepared by using nanocellulose (CNC) to enhance and modify calcium alginate fibers. The mass ratio of the dry weight of nanocellulose CNC to the mass of the used alginic acid was 0.5:100. The specific method was as follows: 0.5 g of nanocellulose (CNC) was dispersed in 5 mL of deionized water, and then it was mixed with the prepared alginic acid solution and placed on a magnetic stirrer to stir evenly to obtain a CA / CNC spinning dope. The method of Step (3) was used to solidify and form solid fibers in a 5% (wt) CaCl2 coagulation bath. After slow and uniform stretching by 2 times and washing with water, CA / CNC composite fibers were obtained.

[0057] Step 6, Preparation of a comparative sample - calcium alginate / microcrystalline cellulose (CA / MCC) composite fibers, that is: 0.5 g of microcrystalline cellulose (MCC) with the same mass as CNC was used to enhance and modify calcium alginate fibers, purchased from Shanghai Macklin Biochemical Co., Ltd. (size <1.0 μm). The fiber preparation method was the same as that in Step (5).

[0058] Step 7, Preparation of calcium alginate / nanocellulose / berberine (CA / CNC / Ber) composite fibers, that is: 10 mL of a 20% (wt) berberine hydrochloride (Ber) solution was evenly dispersed in an ethanol solution with the aid of a magnetic stirrer, and then 2 mL was aspirated and mixed with the 100 g of alginic acid solution prepared in Step (2) and the 5 g of CNC dispersion prepared in Step (5) and placed on a magnetic stirrer to stir for 30 min. First, alginate anions were formed, and then electrostatic attraction occurred with berberine quaternary alkaloid C 20 H 18 NO4 + to form a binding, and a CA / CNC / Ber spinning dope was obtained. The method for preparing CA / CNC / Ber composite fibers was the same as that in Step (5).

[0059] Step 8, Crosslinking treatment with an amine crosslinking agent, that is: a 2% (wt) crosslinking agent solution was used as the crosslinking agent, and then the wet fibers prepared in Steps (3), (5), (6), and (7) were soaked in the crosslinking agent solution for 60 min, taken out after crosslinking, and modified composite fibers were obtained.

[0060] Step 9, Fiber mechanical property tests, morphological characterization, moisture absorption and swelling rate, degradation cycle analysis, and antibacterial rate tests were respectively carried out on the prepared CA filament fibers, CA / CNC filament fibers, CA / MCC filament fibers, and CA / CNC / Ber drug-loaded composite filaments. The tensile breaking strength of the filament fibers increased from 16.35 cN / dtex of the unmodified ones to 38.75 cN / dtex after modification, and the degradation cycle was extended from 2 days to 4 days. The morphological test results were similar to those in Example 1.

[0061] Upon analysis, compared with Example 1, in Example 2, the addition amount of CNC was reduced. At the same time, the mechanical strength decreased, from 43.25 cN / dtex to 38.75 cN / dtex. On the contrary, it shows that appropriately increasing the dosage of CNC can increase the mechanical strength performance of the filament fiber and also appropriately increase the degradation period.

[0062] Comparative Example 1:

[0063] In the comparative example, microcrystalline cellulose MCC was used instead of nanocellulose CNC, and the preparation method of the CA / MCC filament fiber was as described in Step 6 of Example 1 and Example 2. The test results of the strength performance are shown in Table 1 and Figure 6 As shown, in Example 1 and Example 2, the breaking strengths of the CA / MCC filament fibers were 24.37 cN / dtex and 23.25 cN / dtex respectively, which were significantly lower than the strengths of the CNC composite fibers, 43.25 cN / dtex and 38.75 cN / dtex. The degradation periods of the obtained CA / MCC filament fibers were 3.5 days and 3 days respectively, which were lower than the degradation periods of the CA / CNC filament fibers obtained in Example 1 and Example 2, 7 days and 4 days.

[0064] The examples and comparative examples described in the present invention are only descriptions of the preferred embodiments of the present invention, and do not limit the concept and scope of the present invention. Without departing from the design concept of the present invention, various modifications and improvements made by those skilled in the art to the technical solutions of the present invention shall fall within the protection scope of the present invention.

Claims

1. A preparation method of a controllable degradation antibacterial filament fiber, characterized in that: It includes the following steps: (1) Prepare a 3-7 wt% calcium chloride coagulation bath; prepare a 3-7 wt% alginic acid solution; disperse nanocellulose in water to obtain a nanocellulose dispersion. (2) Preparation of calcium alginate / nanocellulose / berberine composite fiber: Dissolve berberine in a solvent to obtain a berberine solution, add it to the alginic acid solution, and add the nanocellulose dispersion. Stir and mix to obtain a spinning dope. Using the wet spinning method, extrude the spinning dope into the calcium chloride coagulation bath with a syringe to form solid fibers, and draw the solid fibers to obtain calcium alginate / nanocellulose / berberine composite fibers. (3) Glutaraldehyde cross-linking: Immerse the calcium alginate / nanocellulose / berberine composite fibers in a 5-10 wt% aqueous glutaraldehyde solution to obtain controllable degradation antibacterial filament fibers.

2. The preparation method of the controllable degradation antibacterial filament fiber according to claim 1, characterized in that: The preparation method of the nanocellulose includes first performing enzymatic hydrolysis with 1-2 wt% cellulase at an enzymatic hydrolysis temperature of 45-50 °C, a pH value of 4.8-5.0, and an enzymatic hydrolysis reaction time of 18 h to terminate the reaction, then cooling to room temperature and centrifuging to collect the precipitate; then performing acid hydrolysis: subject the centrifuged precipitate to acid degradation, add it to a sulfuric acid solution with a volume concentration of 50-55% according to a solid-liquid mass ratio of 1:10, and perform acid hydrolysis at 35-40 °C for 2-2.5 h to obtain nanocellulose with an aspect ratio > 200 and a length > 10 μm.

3. The preparation method of the controllable degradation antibacterial filament fiber according to claim 1 or 2, characterized in that: The mass concentration of the nanocellulose dispersion is 20-40%.

4. The preparation method of the controllable degradation antibacterial filament fiber according to claim 1 or 2, characterized in that: In step (2), the mass ratio of nanocellulose to the alginic acid solution is 1-1.5:

100.

5. The preparation method of the controllable degradation antibacterial filament fiber according to claim 1 or 2, characterized in that: In step (2), the mass concentration of the berberine solution is 20-25%.

6. The preparation method of the controllable degradation antibacterial filament fiber according to claim 5, characterized in that: In step (2), the volume ratio of the berberine solution to the alginic acid solution is 2-5:

100.

7. The preparation method of the controllable degradation antibacterial filament fiber according to claim 1 or 2, characterized in that: In step (2), the draw ratio is 2-4 times.

8. The preparation method of the controllable degradation antibacterial filament fiber according to claim 1 or 2, characterized in that: In step (2), the solvent is a mixed solution of ethanol and water with a volume ratio of ethanol to water of 1:

1.

9. The preparation method of the controllable degradation antibacterial filament fiber according to claim 1 or 2, characterized in that: In step (3), the soaking time is 30-90 min; for the extrusion and coagulation, the coagulation time is 5-10 min.

10. The controllable degradation antibacterial filament fiber prepared by the preparation method of the controllable degradation antibacterial filament fiber according to claim 1.

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