A modified chitosan adhesive fiber membrane and a green preparation method thereof
Through the green preparation method of modified chitosan fiber membrane, the low production efficiency and safety problems of chitosan fiber in the solution blowing spinning process are solved, the antibacterial and adhesion properties of the fiber are improved, and it is suitable for medical devices and medical protection.
Patent Information
- Application Number
- CN202310751584.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2023-06-25
- Publication Date
- 2025-09-30
- Estimated Expiration
- 2043-06-25
AI Technical Summary
Existing chitosan fibers have problems such as slow production speed, high cost, weak antibacterial properties, poor liquid absorption and poor tissue adhesion during the solution blowing spinning process, and the use of acidic or organic solvents is harmful to the human body.
Chitosan grafted with catechol (CS-C) was used as raw material, a mixed solvent of water and ethanol was used, and polyethylene oxide (PEO) was combined as a spinning aid. The modified chitosan adhesive fiber membrane was prepared by solution blowing spinning process to achieve green production.
The spinnability and adhesion of chitosan fibers are improved, and the antibacterial and liquid absorption properties are enhanced. The prepared fiber membrane has uniform diameter and smooth surface, and is suitable for medical devices and medical protection fields.
Smart Images
Figure CN116785488B_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the field of chitosan fiber membranes, and in particular to a modified chitosan adhesive fiber membrane and an environmentally friendly preparation method thereof. Background Art
[0002] Chitosan is a high molecular compound extracted from the shells of crustaceans such as shrimp and crabs. It is the most abundant high molecular polymer found on Earth besides cellulose. It has the advantages of being non-toxic, biocompatible and biodegradable. Because its molecular structure contains unsaturated cationic groups, it has a strong adsorption effect on various harmful substances and harmful bacteria with negative charges, thereby inhibiting the activity of harmful bacteria and making them inactive, and has a good antibacterial effect.
[0003] Chitosan fiber is widely used in wound hemostasis, wound repair and other fields due to its good biocompatibility, antibacterial properties and degradability. However, due to its limited solubility, chitosan can only be dissolved in acidic solutions and the high degree of entanglement between molecular chains, which makes chitosan spinnable. Moreover, chitosan fiber is currently mainly produced through electrospinning technology, which has problems such as slow production speed and high production cost.
[0004] Solution blown spinning (SBS) technology has attracted widespread attention from researchers due to its advantages such as low cost, simple operation, fast spinning speed, and continuous large-scale production. However, chitosan fibers prepared by the solution blown spinning method still have the following problems: ① Since chitosan itself can only be dissolved in acidic solutions, acidic solvents or organic solvents are often used in the current production process, which can irritate and harm human skin, respiratory system, nervous system, etc.; ② Due to the poor spinnability of chitosan, the prepared chitosan fibers contain less chitosan and more spinning aid polymers. The ratio of chitosan to spinning aid polymers can reach up to 10:90. In the application of wound healing and repair, there are still defects such as weak antibacterial properties and poor liquid absorption; ③ The currently prepared fibers have almost no adhesion and cannot adhere well to tissues, resulting in unsatisfactory application results in the field of wound repair.
[0005] Research has found that marine mussel adhesive proteins possess high strength, toughness, and water resistance, as well as strong matrix adhesion. This is due to the presence of a large number of DOPA groups within the mussel adhesive protein molecules. Oxidized and unoxidized DOPA undergo self-oxidation and cross-linking in the environment to form a microscopic, discontinuous network of bioscaffolds, giving the mussel protein excellent underwater adhesion. It also possesses excellent biocompatibility and degradability, making it a highly advantageous and promising biomedical adhesive. Therefore, how to apply the DOPA group structure to the fiber field to improve fiber adhesion is also a current research focus. Summary of the Invention
[0006] Based on this, the present invention provides a modified chitosan adhesive fiber membrane and its green preparation method. The present invention uses catechol-grafted modified chitosan (CS-C) as a raw material, which has good water solubility. By reducing the number of amino groups on the chitosan molecular chain and reducing the entanglement between chitosan molecular chains, the spinnability of chitosan is greatly improved. Polyethylene oxide (PEO) is used as a spinning aid polymer, and ethanol and water are used as solvents. The modified chitosan adhesive fiber membrane is prepared using a solution blown spinning process. The present invention achieves a green production process, eliminating the need to consider solvent volatilization and recovery issues, and the chitosan content in the prepared chitosan fiber membrane is significantly increased.
[0007] To achieve the above object, the present invention provides a green preparation method of modified chitosan adhesive fiber membrane, which is specifically carried out according to the following steps:
[0008] ① Accurately weigh a certain amount of chitosan powder, soak the chitosan with dilute hydrochloric acid, wait until the chitosan becomes light yellow and transparent, add a small amount of water and stir to dissolve, adjust the pH of the chitosan solution to 5.0-5.5 with NaOH solution; continue stirring until the solution is transparent and clear to obtain a chitosan solution.
[0009] ② Dissolve a certain amount of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDC) and hydrogenated caffeic acid (HCA) in ethanol and deionized water in a volume ratio of 1:1, mix and stir for 5 to 10 minutes to obtain a clear light yellow solution.
[0010] ③ Slowly add the clear light yellow solution prepared in step ② to the chitosan solution in step ①, and the addition process is carried out under stirring. After the addition is completed, continue stirring and react for 12 to 24 hours. During the reaction, maintain the solution pH = 4.5 to 5.0.
[0011] ④ Place the solution obtained in step ③ into a dialysis bag with a molecular weight cutoff of 3000 and dialyze it in a dilute NaCl solution with a pH of 4.5 to 5.0 for 2 to 3 days, replacing the dialysate every 4 to 6 hours, and finally dialyze it in deionized water with a pH of 4.5 to 5.0 for 4 to 12 hours.
[0012] ⑤ Freeze-dry the dialyzed solution in step ④ to obtain gray foamy catechol-grafted modified chitosan, which is then sealed and stored in a drying cabinet.
[0013] ⑥ Dissolve the modified chitosan and a spinning aid in a mixed solvent of water and ethanol in a certain proportion, and stir to obtain a spinning solution. The spinning aid is one or a mixture of two or more of polyethylene oxide (PEO), polyvinyl alcohol, and polyvinyl pyrrolidone.
[0014] ⑦ Using solution blowing spinning technology, the prepared spinning solution is placed in a syringe, the spinning speed and collection distance are adjusted, and the prepared fibers are deposited on a receiver to obtain a modified chitosan adhesive fiber membrane with an average fiber diameter of 200 to 500 nm.
[0015] Furthermore, in step ⑤, the grafting rate of the modified chitosan is 10%-20%.
[0016] Furthermore, in step ⑥, in the mixed solvent of water and ethanol, water accounts for 10 to 35 parts and ethanol accounts for 90 to 65 parts.
[0017] Furthermore, in step ⑥, in the spinning solution, the modified chitosan accounts for 1 to 40 parts, and the spinning aid accounts for 99 to 60 parts. Preferably, the modified chitosan accounts for 30 to 40 parts, and the spinning aid accounts for 70 to 60 parts.
[0018] Furthermore, in step ⑥, the total concentration of the spinning solution is 0.5-2.5%, where the total concentration refers to the volume fraction of the total amount of modified chitosan and polyethylene oxide in the solution.
[0019] Furthermore, in step ⑥, the receiver is any one of a metal mesh, a plastic mesh or a non-woven fabric with a porous structure.
[0020] Furthermore, in step ⑦, the air humidity is lower than 40%, the temperature is room temperature to 80°C, the extrusion speed of the mixed spinning solution is 50 to 80 μL / min, the distance between the spinneret of the syringe and the receiver is 40 to 80 cm, and compressed air is used to form a high-speed airflow with a flow rate of 5 to 50 m / s. The winding speed of the collecting reel is 500 to 1000 r / min.
[0021] According to another aspect of the present invention, the present invention also provides a modified chitosan adhesive fiber membrane, which is prepared by the above method.
[0022] The modified chitosan adhesive fiber membrane and the green preparation method thereof of the present invention adopt the above technical scheme to achieve the following
[0023] Beneficial effects:
[0024] 1. Regarding solvent selection, water is one of the most common substances on Earth, covering approximately 71% of the Earth's surface. Ethanol, whose raw materials come from green plants, is considered a green energy source. The present invention uses a mixed solution of water and ethanol as the solvent in the spinning solution. A spinning aid soluble in the mixed solvent is employed to improve spinnability. Modified chitosan is used to increase its solubility, thereby avoiding the use of acidic and organic solvents. This achieves a green, safe, and environmentally friendly production process.
[0025] 2. Modified chitosan has good water solubility, which improves the spinnability and adhesion of chitosan. During the preparation of the spinning solution, the ratio of modified chitosan to spinning aid in the spinning solution can be increased from 1:99 to 40:60. The chitosan content in the prepared fiber membrane is greatly increased, thereby significantly improving the antibacterial and liquid absorption properties. It has broad application prospects in medical devices, medical protection and other fields;
[0026] 3. The present invention improves the spinnability of the modified chitosan system by selecting a spinning aid with excellent spinnability, less molecular entanglement, and easy fiber production. The prepared modified chitosan adhered fiber membrane has the advantages of uniform diameter and smooth surface. The uniform fiber diameter makes the porosity and air permeability more uniform and controllable. The smooth fibers make the fiber membrane surface smoother and more comfortable, making it easier to process and use.
[0027] 4. Based on solution blowing spinning technology, the present invention explores a green preparation method for chitosan fiber membrane, which has a wide source of raw materials, a simple preparation process, low cost, and a green and environmentally friendly production process, and has good prospects for industrial application. BRIEF DESCRIPTION OF THE DRAWINGS
[0028] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.
[0029] Figure 1 The modified chitosan adhesive fiber membrane prepared in Example 1, as well as the infrared spectra of CS-C and PEO;
[0030] Figure 2 This is a scanning electron microscope image of the modified chitosan adhesion fiber membrane prepared in Example 1, with a scale of 10 μm;
[0031] Figure 3 This is a scanning electron microscope image of the modified chitosan adhesion fiber membrane prepared in Example 2, with a scale of 10 μm;
[0032] Figure 4 This is a scanning electron microscope image of the modified chitosan adhesion fiber membrane prepared in Example 3, with a scale of 5 μm.
[0033] The purpose, features and advantages of the present invention will be further described with reference to the accompanying drawings and in conjunction with the embodiments. DETAILED DESCRIPTION
[0034] The following describes the specific embodiments of the present invention in detail with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present invention and are not intended to limit the present invention.
[0035] Unless otherwise defined, the technical terms used in the following examples have the same meanings as commonly understood by those skilled in the art to which this invention belongs. The experimental reagents used in the following examples, unless otherwise specified, are conventional biochemical reagents; the experimental methods described, unless otherwise specified, are conventional methods.
[0036] The raw materials used in the following examples were all commercially available. The chitosan had a molecular weight of 100 kDa and a degree of deacetylation of 85% before modification. Modified chitosan was obtained by dropwise adding a 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride solution and a hydrogenated caffeic acid solution to a chitosan solution for reaction. After completion of the reaction, the chitosan was dialyzed and freeze-dried to obtain the modified chitosan.
[0037] Example 1
[0038] This embodiment provides a green preparation method for a modified chitosan adhesive fiber membrane, which specifically comprises the following steps:
[0039] Preparation of spinning solution: Dissolve 0.0225 g of modified chitosan (CS-C) with a grafting rate of 10% in 1.5 mL of deionized water until fully dissolved, then dissolve 0.0525 g of polyethylene oxide (PEO) with a molecular weight of 600,000 in 3.5 mL of anhydrous ethanol. Heat at 60°C until both solutions are fully dissolved, mix them, and continue stirring until the mixture is uniform to obtain a spinning solution.
[0040] Solution blowing spinning: The spinning solution is loaded into a 5mL syringe, and the syringe is placed on a syringe pump. The needle is bent at 90° and kept parallel to the gas nozzle (used to eject high-speed airflow). The injection rate is adjusted to 50uL / min, and the collection distance of the reel is adjusted to 60cm. Under the conditions of room temperature of 30°C and air humidity of 40%, compressed nitrogen is used as the gas source to provide an airflow with a flow rate of 5-50m / s and ejected from the gas nozzle. An injection propeller is used to squeeze the spinning solution out of the needle, and a high-flow airflow is used to stretch the spinning solution into a nanofiber form. The air inlet pressure is 0.05Mpa. Finally, the fibers are deposited on the non-woven fiber cloth to form a modified chitosan adhesion fiber membrane. The fiber diameter is at the nanometer level, also known as a nanofiber membrane.
[0041] The infrared transmission spectra of the nanofiber membrane, CS-C and PEO obtained above were detected by Fourier transform infrared spectrometer. Figure 1 It can be seen that in the spectrum of the nanofiber membrane (Fiber), a broad peak appears at 3356 cm. This is caused by the overlapping and broadening of the OH and NH absorption peaks under the action of hydrogen bonds within the CS-C molecules after the addition of PEO. This indicates that there is a strong hydrogen bond between CS-C and PEO molecules in the blended fiber.
[0042] The scanning electron microscope image of the nanofiber membrane obtained above is as follows: Figure 2 , it can be observed that the fiber surface is smooth and flexible, and the fiber diameter is at the nanometer level.
[0043] Comparative Example 1
[0044] This comparative example is a comparison experiment to Example 1. The same preparation method as Example 1 was used, except that the chitosan used to prepare the spinning solution was not modified. Because unmodified chitosan is insoluble in water, effective continuous spinning during the solution-blown spinning process is impossible. Furthermore, due to the strong entanglement between chitosan molecular chains, the spinning process also presents problems such as needle clogging.
[0045] The reason why the present invention is superior to comparative example 1 in preparing nanofiber membrane using modified chitosan as raw material is that water can be used as solvent to achieve economical and environmentally friendly process production. Since the number of amino groups on the molecular chain of chitosan is reduced after modification, the entanglement between molecules is weakened, which not only helps continuous spinning, but also increases the proportion of chitosan usage, thereby improving application performance.
[0046] Example 2
[0047] This embodiment provides a green preparation method for a modified chitosan adhesive fiber membrane, which specifically comprises the following steps:
[0048] Preparation of spinning solution: Dissolve 0.015 g of modified chitosan with a grafting rate of 10% in 1.5 mL of deionized water until fully dissolved, then dissolve 0.035 g of polyethylene oxide with a molecular weight of 600,000 in 3.5 mL of anhydrous ethanol. Heat at 60°C until both are fully dissolved, mix them, and continue stirring until the mixture is uniform to obtain a spinning solution.
[0049] Solution blowing spinning: The spinning solution is loaded into a 5mL syringe, and the syringe is placed on the syringe pump. The needle is bent at 90° and kept parallel to the gas nozzle. The injection rate is adjusted to 120uL / min, and the collection distance of the reel is adjusted to 60cm. Under the conditions of room temperature of 30°C and air humidity of 30%, compressed nitrogen is used as the gas source to provide an air flow with a flow rate of 5-50m / s. The spinning solution is squeezed out of the needle using an injection propeller, and the spinning solution is stretched into a nanofiber form using a high-flow airflow. The air inlet pressure is 0.05Mpa. Finally, the fibers are deposited on the non-woven fiber cloth to form a nanofiber membrane.
[0050] The scanning electron microscope image of the nanofiber membrane obtained above is as follows Figure 3 As shown, it can be seen that the fiber surface is smooth and flexible, and the fiber diameter is at the nanometer level.
[0051] Example 3
[0052] This embodiment provides a green preparation method for a modified chitosan adhesive fiber membrane, which specifically comprises the following steps:
[0053] Preparation of spinning solution: Dissolve 0.024 g of modified chitosan with a grafting rate of 20% in 1.5 mL of deionized water until fully dissolved, then dissolve 0.056 g of polyethylene oxide with a molecular weight of 600,000 in 3.5 mL of anhydrous ethanol. Heat at 60°C until both are fully dissolved, mix them, and continue stirring until the mixture is uniform to obtain a spinning solution.
[0054] Solution blowing spinning: The spinning solution is loaded into a 5mL syringe, and the syringe is placed on a syringe pump. The needle is bent at 90° and kept parallel to the gas nozzle. The injection rate is adjusted to 50uL / min, and the collection distance of the reel is adjusted to 60cm. Under the conditions of room temperature of 30°C and air humidity of 30%, compressed nitrogen is used as the gas source to provide an air flow with a flow rate of 5 to 50m / s. The spinning solution is squeezed out of the needle using an injection propeller, and the spinning solution is stretched into a nanofiber form using a high-flow airflow. The air inlet pressure is 0.05Mpa. Finally, the fibers are deposited on the non-woven fiber cloth to form a nanofiber membrane.
[0055] The scanning electron microscope image of the nanofiber membrane obtained above is as follows: Figure 4 , it can be seen that the fiber surface is smooth and flexible, and the fiber diameter is at the nanometer level.
[0056] Example 4
[0057] The same preparation method and material ratio as in Example 1 were used, except that the spinning aid was replaced by polyvinyl alcohol, to obtain a polyvinyl alcohol / modified chitosan nanofiber membrane.
[0058] Example 5
[0059] The same preparation method and material ratio as in Example 1 were adopted, except that the spinning aid was replaced by polyvinyl pyrrolidone, to obtain a polyvinyl pyrrolidone / modified chitosan nanofiber membrane.
[0060] Compared with Example 1, Examples 4 and 5 also have very good spinnability, are suitable for solution blowing spinning, and can obtain high-content chitosan fiber membranes.
[0061] In addition, the nanofiber membranes of Examples 4 and 5 were characterized and detected by scanning electron microscopy, and it can be seen that the fiber surface is smooth and flexible, and the fiber diameter is at the nanometer level.
[0062] To illustrate the beneficial effects of the present invention, nanofiber membranes prepared with varying amounts of modified chitosan were used as wound dressings. It was found that increasing the amount of modified chitosan resulted in stronger antibacterial properties and improved adhesion, further aiding wound recovery. Based on the feed ratio, the preferred spinning solution contains 30-40 parts modified chitosan and 70-60 parts spinning aid. As the modified chitosan content increases beyond 40 parts by weight, continuous spinnability decreases, hindering spinning.
[0063] Although specific embodiments of the present invention are described above, those skilled in the art should understand that these are merely examples and that various changes or modifications may be made to the embodiments without departing from the principles and essence of the present invention. The scope of protection of the present invention is limited only by the appended claims.
Claims
1. A green preparation method for modified chitosan adhesive fiber membrane, characterized in that: The following steps are involved: S1. Dissolving the modified chitosan grafted with catechol in water and dissolving the cosolvent in ethanol, mixing the two after they are fully dissolved, and stirring evenly to obtain a spinning solution comprising 30-40 parts of the modified chitosan and 70-60 parts of a spinning aid, wherein the spinning aid is one or a mixture of two or more of polyethylene oxide, polyvinyl alcohol, and polyvinyl pyrrolidone; S2. Using solution blowing spinning technology, the spinning solution is placed in a syringe, and the spinning solution is extruded under the action of the injection thrust. At the same time, the extruded spinning solution is stretched into nanofibers by a high-speed airflow and adhered to a receiver to obtain a modified chitosan adhesive fiber membrane; The proportions of water and ethanol are: water accounts for 10-35 parts, and ethanol accounts for 90-65 parts; the total concentration of the spinning solution is 0.5-3.5%, and the total concentration refers to the total volume fraction of the modified chitosan and polyethylene oxide in the solution.
2. The green preparation method of modified chitosan adhesive fiber membrane according to claim 1, characterized in that: The catechol-grafted modified chitosan is prepared by the following steps: A mixed solution of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride solution and hydrogenated caffeic acid is added dropwise to a chitosan solution for reaction. After the reaction is completed, the solution is dialyzed and freeze-dried to obtain modified chitosan.
3. The green preparation method of modified chitosan adhesive fiber membrane according to claim 1, characterized in that: The receiver is any one of a metal mesh, a plastic mesh or a non-woven fabric with a porous structure.
4. The green preparation method of modified chitosan adhesive fiber membrane according to claim 1, characterized in that: In step S2, the spinning process parameters are as follows: air humidity is less than 40%, temperature is room temperature to 80°C, extrusion speed of the spinning solution is 50 to 80 μL / min, the distance between the spinneret of the syringe and the receiver is 40 to 80 cm, the flow rate of the high-speed airflow is 5 to 50 m / s, and the winding speed of the collecting reel is 500 to 1000 r / min.
5. The green preparation method of modified chitosan adhesive fiber membrane according to claim 1, characterized in that: The average diameter of the fibers in the modified chitosan adhesive fiber membrane is 200-500 nm.
6. A modified chitosan adhesive fiber membrane, characterized in that: The modified chitosan adhesive fiber membrane is prepared by the green preparation method of any one of claims 1 to 5.