A method for preparing a porous electrospun nanofiber biocarrier by organic vapor swelling

Abstract

The present application belongs to the technical field of microbial carrier preparation, and discloses a method for preparing a porous electrospun nanofiber biological carrier by an organic vapor swelling method. The method prepares nanofibers by an electrospinning technology, and then performs swelling treatment by using organic vapor to form a porous structure, thereby increasing the specific surface area and adsorption capacity of the fibers. By controlling the swelling conditions, the porous structure and pore size can be accurately regulated to meet different application requirements. The porous electrospun nanofiber biological carrier has good biocompatibility and biological activity, and is suitable for fields such as biological culture, pollution control, drug delivery and biosensing. The method is simple to operate and can be prepared on a large scale, and has a broad application prospect. The implementation of the present application not only provides a new method for preparing porous electrospun nanofibers, but also provides a new idea for the development of the field of biological materials.

Description

Technical Field

[0001] This invention belongs to the field of microbial carrier preparation technology, and relates to a method for preparing porous electrospun nanofiber biological carriers by organic vapor swelling. Background Technology

[0002] In the field of biomaterials science, nanofibers have attracted widespread attention and research due to their unique nanoscale structure, high specific surface area, and good biocompatibility. Especially in biomedicine, tissue engineering, drug delivery, and biosensing, nanofibers have enormous application potential. Electrospun nanofibers, as an important nanofiber preparation technology, possess significant application value in the field of biomaterials preparation due to their advantages such as good continuity, controllable structure, and high production efficiency.

[0003] In the process of preparing nanofiber biocarriers, researchers have discovered that introducing porous structures can further increase the specific surface area of ​​nanofibers, improve their bioactivity, and enhance their drug loading and release capabilities. Porous structures not only facilitate cell adhesion and proliferation but also contribute to improving the biocompatibility and bioactivity of biomaterials. Therefore, the preparation of electrospun nanofiber biocarriers with porous structures has become one of the current research hotspots in the field of biomaterials.

[0004] Currently, there are various methods for preparing porous electrospun nanofiber biocarriers, including template methods, chemical etching methods, and physical treatment methods. Patent CN117026425A uses zinc oxide etching to prepare carbon nanofibers, which, while achieving a porous structure, relies on chemical etching steps and poses environmental pollution risks. The melt differential electrospinning device disclosed in CN204608226 is only suitable for melt spinning, and the high-speed airflow easily leads to severe fiber breakage. While the centrifugal spinning method in US patent US8721319B2 is highly efficient, the products are mostly fiber membranes or fiber webs, making precise pore size control difficult. The dual-electrode electrospinning device in CN105734693A suffers from low production efficiency and high raw material requirements, while the spherical brush-type device in CN106811845B suffers from uneven spinning and clogging problems due to exposure of the spinning solution.

[0005] Therefore, developing a simple, efficient, and environmentally friendly method for preparing porous electrospun nanofiber biocarriers has significant scientific and application value. Organic vapor swelling, as a novel method for nanofiber porosification, is simple to operate, low-cost, and pollution-free, making it a promising candidate for nanofiber porosification. In this method, organic vapor plays a crucial role. It interacts with the nanofiber surface, causing the fibers to swell and form a porous structure within them. By selecting appropriate organic vapors and controlling the swelling conditions, precise control of the nanofiber porous structure can be achieved. Patent CN114933897A uses acetone swelling to prepare fluorescent microspheres, but this is limited to biodetection probes and does not address nanofiber porosity control. CN102382227A relies on crosslinking agents and secondary polymerization to control pore size, resulting in a complex process and pore sizes of only 100-300 nm. A 2024 review in *Journal of Luminescence* points out that traditional swelling methods suffer from solvent residue and structural collapse problems. In summary, although the organic vapor swelling method has potential advantages in the preparation of porous electrospun nanofiber biocarriers, research on this method is still in its early stages. Summary of the Invention

[0006] This invention is made in view of the above-mentioned problems existing in the prior art. The purpose of this invention is to provide a method for preparing porous electrospun nanofiber biological carriers by organic vapor swelling method, so as to enhance the loading and binding efficiency of biological carriers for microorganisms, and provide better biological carriers for wastewater treatment, biopharmaceutical and other fields.

[0007] The novelty of this invention lies in breaking through the bottleneck of traditional porous electrospun nanofiber preparation by pioneering a synergistic process of organic vapor swelling and surface plasma pretreatment. Compared with the complex structure destruction of template methods, the high pollution of chemical etching methods, and the low strength of physical treatment methods, this method uses organic vapors such as acetone and methanol as swelling media, requires no corrosive reagents, and is simple and environmentally friendly. By constructing depressions on the fiber membrane surface through surface plasma pretreatment, the vapor penetration efficiency is greatly improved, and uniform pore formation is achieved.

[0008] Meanwhile, by adjusting parameters such as vapor type, concentration, and temperature, the pore size, pore distribution, and pore density can be precisely controlled to meet the needs of diverse scenarios. The prepared carrier has a large specific surface area and excellent biocompatibility. For example, in the examples, the anaerobic sludge loading rate is 2.5 times that of commercially available packing materials, providing a highly efficient carrier for wastewater treatment, biopharmaceuticals, and other fields, combining scientific innovation with engineering application value.

[0009] The technical solution of this invention: A method for preparing porous electrospun nanofiber biocarriers using an organic vapor swelling method includes the following steps: Step 1: Dissolve a high-molecular-weight polymer with high spinnability and biocompatibility in a mixed solution of dichloromethane and acetonitrile to prepare an electrospinning solution; use acetone, methanol, chloroform, etc. as organic vapors that have a swelling effect on nanofibers; Step 2: Inject the electrospinning solution into the electrospinning equipment, adjust the voltage, current, electrospinning solution flow rate and other parameters, and carry out electrospinning operation. Under the action of the electric field, the electrospinning solution forms a jet and is stretched and refined, and finally deposited on the collector to obtain a fiber membrane woven from smooth polymer nanofibers. Step 3: The smooth surface of the fiber membrane is pretreated by surface plasma treatment to create pores and a recessed structure on the surface of the fiber membrane to facilitate the penetration of organic vapors. Step 4: Place the pretreated fiber membrane in a sealed container, slowly introduce organic vapor, control the volume concentration of organic vapor in the container to be 1~10%, the treatment temperature to be room temperature, and the treatment time to be 10min~2h, so that the fiber membrane swells under the action of organic vapor. During this process, the organic vapor interacts with the surface of the nanofiber, causing swelling and pores to form inside the fiber membrane. Step 5: After organic vapor swelling treatment, the fiber membrane is taken out and dried; the drying temperature is controlled at 60℃~90℃ and the drying time is 3h~6h to remove the residual organic vapor and solvent in the fiber membrane and fix the fiber structure. After drying, the temperature is further raised to 120℃ for heat treatment to enhance the mechanical properties and stability of the nanofibers and obtain porous electrospun nanofiber biocarriers. Step 6: The prepared porous electrospun nanofiber biological carrier is cleaned, disinfected and other post-processed to meet the needs of practical applications such as biological and cell fixation and carrier embedding. Finally, the performance of the porous electrospun nanofiber biological carrier is tested, including indicators such as pore size, pore distribution, specific surface area and biocompatibility, to evaluate its quality and applicability.

[0010] The high-spinnability and biocompatibility polymer mentioned in step 1 is one of nylon, polypropylene, polyethylene, polyethyl acetate, and polylactic acid; the mass ratio of dichloromethane to acetonitrile in the mixed solution of dichloromethane and acetonitrile is 10:1 to 100:1; the mass concentration of the electrospinning solution is 10 to 15%. The electrospinning equipment mentioned in step 2 is a high-voltage electrospinning equipment, with the voltage adjusted to 5000~20000V, the current to 0.01A~0.1A, and the electrospinning solution flow rate to 0.1mL / min~1mL / min.

[0011] The surface plasma treatment described in step 3 involves placing the fiber membrane in a vacuum evaporation apparatus, first evacuating it to 0.1 Pa, then introducing argon gas to 1 Pa, applying a voltage of 2000 V to generate glow discharge, and treating for 5 minutes.

[0012] Porous electrospun nanofiber biocarriers are a novel type of biomaterial. Their unique nanoscale and porous structure endows them with excellent biocompatibility and bioactivity.

[0013] The beneficial effects of this invention are: This invention enables precise control over the porous structure of nanofibers, further expanding their application scope in cell culture, tissue engineering, drug delivery, and biosensing.

[0014] Secondly, the main technical advantage of this invention lies in its simple, efficient, and environmentally friendly preparation process. Compared with traditional template methods and chemical etching methods, the organic vapor swelling method requires no complex preparation steps or corrosive reagents, is simple to operate, and has low cost. Furthermore, this method does not require the use of toxic or harmful reagents, making it environmentally friendly and in line with the development trend of green chemistry.

[0015] Furthermore, this invention offers advantages such as controllable preparation conditions and adjustable product performance. By adjusting parameters such as the type, concentration, and temperature of organic vapors, precise control over the porous structure of nanofibers can be achieved, resulting in porous electrospun nanofiber biocarriers with different pore sizes, pore distributions, and pore densities. This tunability allows the method to meet the needs of different application scenarios, providing greater flexibility for practical applications.

[0016] Finally, the porous electrospun nanofiber biocarrier of this invention exhibits excellent biocompatibility and bioactivity. The porous structure not only increases the specific surface area of ​​the fibers and enhances their adsorption capacity, but also promotes cell adhesion and proliferation. Attached Figure Description

[0017] Figure 1 The image shows a scanning electron microscope image of the smooth surface electrospun nanofiber membrane material obtained in step 2. Figure 2 A scanning electron microscope image of a porous nanofiber membrane material that has undergone swelling treatment; Figure 3 This shows the growth of anaerobic sludge on the surface of the nanofiber membrane material after 10 days of loading. Detailed Implementation

[0018] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings and technical solutions.

[0019] Example 1 A method for preparing porous electrospun nanofiber biocarriers using an organic vapor swelling method is disclosed. First, nylon, a polymer with high spinnability and biocompatibility, is prepared and dissolved in a mixed solution of dichloromethane and acetonitrile (mass ratio 10:1) to prepare a 10% electrospinning solution. Simultaneously, acetone is prepared as an organic vapor source that swells the nanofibers. Then, the prepared electrospinning solution is injected into an electrospinning apparatus, with the electrospinning voltage set to 5000V, the current to 0.01A, and the solution flow rate to 0.1mL / min. The resulting electrospun fiber membrane has a width of 50×50cm. 2 Under the influence of an electric field, the electrospinning solution forms a jet and is stretched and refined, eventually depositing onto a collector to obtain smooth polymer nanofibers (such as...). Figure 1 As shown), the nanofibers are pretreated on their smooth surface using surface plasma treatment. The nanofiber membrane is placed in a vacuum evaporator, first evacuated to 0.1 Pa, then a small amount of argon gas is introduced to 1 Pa, and a voltage of 2000 V is applied to generate glow discharge. This plasma treatment lasts for 5 minutes, creating pores and recesses on the fiber surface to facilitate the penetration of acetone vapor. The pretreated nanofibers are then placed in a sealed container, and acetone vapor is slowly introduced. By controlling the volume concentration of acetone vapor in the container to 1%, maintaining room temperature, and treating for 10 minutes, the nanofibers swell under the influence of the acetone vapor. During this process, the acetone vapor interacts with the nanofiber surface, causing swelling and pores (such as...) inside the fibers. Figure 2 As shown in the figure, after swelling with acetone vapor, the nanofibers are removed and dried. By controlling the drying temperature to 60℃ and the drying time to 3 hours, residual acetone vapor and solvent in the nanofibers are removed, thus fixing the fiber structure. After drying, further curing treatments such as heat treatment at 120℃ or chemical cross-linking can be performed to enhance the mechanical properties and stability of the nanofibers. The prepared porous electrospun nanofiber biocarriers are then cleaned, disinfected, and post-treated to meet the needs of practical applications such as biological and cell fixation and carrier embedding. Finally, the performance of the porous electrospun nanofiber biocarriers is tested, including indicators such as pore size, pore distribution, specific surface area, and biocompatibility, to evaluate its quality and applicability.

[0020] After the above treatment, the porous electrospun nanofiber membrane can effectively load anaerobic activated sludge, with a sludge loading rate 2.5 times that of commercially available wire mesh packing. Its scanning electron microscope image is shown below. Figure 3 As shown.

[0021] Example 2 A method for preparing porous electrospun nanofiber biocarriers using an organic vapor swelling method involves first preparing polypropylene particles and dissolving them in a mixed solution of dichloromethane and acetonitrile at a mass ratio of 100:1. Simultaneously, methanol is prepared as an organic vapor source to promote the swelling of the nanofibers. Then, a 12% (w / w) electrospinning solution is injected into an electrospinning apparatus. The voltage is adjusted to 20000V, corresponding to a current of 0.1A, and the solution flow rate is 1mL / min. Electrospinning is then performed, resulting in an electrospun fiber membrane with a width of 50×50cm. 2 The nanofibers were pretreated using surface plasma treatment. The nanofiber membrane was placed in a vacuum evaporator, evacuated to 0.1 Pa, then a small amount of argon gas was introduced to 1 Pa. A voltage of 2000 V was applied to generate glow discharge. This plasma treatment lasted for 5 minutes, creating pores and recesses on the fiber surface to facilitate the penetration of acetone vapor. The pretreated nanofibers were then placed in a sealed container, and methanol vapor was slowly introduced. By controlling the methanol vapor concentration in the container to 10%, maintaining room temperature, and treating for 30 minutes, the nanofibers swelled under the influence of methanol. During this process, the methanol vapor interacted with the nanofiber surface, causing swelling and pores within the fibers. After the methanol vapor swelling treatment, the nanofibers were removed and dried. By controlling the drying temperature to 90℃ and the drying time to 6 hours, residual methanol vapor and solvent in the nanofibers were removed, thus fixing the fiber structure. After drying, further curing treatments such as heat treatment at 120℃ or chemical cross-linking were performed to enhance the mechanical properties and stability of the nanofibers. The prepared porous electrospun nanofiber biocarriers were then cleaned, disinfected, and post-treated to meet the needs of practical applications such as biological and cell fixation and carrier embedding. Finally, the performance of the porous electrospun nanofiber biocarriers was tested, including indicators such as pore size, pore distribution, specific surface area, and biocompatibility, to evaluate their quality and applicability.

[0022] Example 3 A method for preparing porous electrospun nanofiber biocarriers using an organic vapor swelling method involves first preparing polyethylene particles and dissolving them in a mixed solution of dichloromethane and acetonitrile at a mass ratio of 25:1. Simultaneously, chloroform is prepared as an organic vapor source to promote the swelling of the nanofibers. Then, a 15% (w / w) electrospinning solution is injected into an electrospinning apparatus. The voltage is adjusted to 12000V, corresponding to a current of 0.055A, and the solution flow rate is 0.47 mL / min. Electrospinning is then performed, resulting in electrospun fiber membranes with a width of 50 × 50 cm. 2The nanofibers were pretreated using surface plasma treatment. The nanofiber membrane was placed in a vacuum evaporator, evacuated to 0.1 Pa, then a small amount of argon gas was introduced to 1 Pa. A voltage of 2000 V was applied to generate glow discharge. This plasma treatment lasted for 5 minutes, creating pores and recesses on the fiber surface to facilitate the penetration of acetone vapor. The pretreated nanofibers were then placed in a sealed container, and chloroform vapor was slowly introduced. By controlling the volume concentration of chloroform vapor in the container to 5%, maintaining room temperature, and treating for 1 hour, the nanofibers swelled under the influence of chloroform. During this process, the chloroform vapor interacted with the nanofiber surface, causing swelling and pores within the fibers. After the chloroform vapor swelling treatment, the nanofibers were removed and dried. By controlling the drying temperature to 70℃ and the drying time to 4 hours, residual chloroform vapor and solvent in the nanofibers are removed, thus fixing the fiber structure. After drying, further curing treatments such as heat treatment at 120℃ or chemical cross-linking are performed to enhance the mechanical properties and stability of the nanofibers. The prepared porous electrospun nanofiber biocarriers are then cleaned, disinfected, and post-treated to meet the needs of practical applications such as biological and cell fixation and carrier embedding. Finally, the performance of the porous electrospun nanofiber biocarriers is tested, including indicators such as pore size, pore distribution, specific surface area, and biocompatibility, to evaluate their quality and applicability.

[0023] Example 4 A method for preparing porous electrospun nanofiber biocarriers using an organic vapor swelling method involves first preparing polyethyl acetate particles and dissolving them in a mixed solution of dichloromethane and acetonitrile at a mass ratio of 75:1. Simultaneously, acetone is prepared as an organic vapor source to promote the swelling of the nanofibers. Then, a 15% (w / w) electrospinning solution is injected into an electrospinning apparatus. The voltage is adjusted to 7200V, corresponding to a current of 0.022A, and the solution flow rate is 0.27 mL / min. Electrospinning is then performed, resulting in electrospun fiber membranes with a width of 50 × 50 cm. 2The nanofibers were pretreated using surface plasma treatment. The nanofiber membrane was placed in a vacuum evaporator, evacuated to 0.1 Pa, then a small amount of argon gas was introduced to 1 Pa. A voltage of 2000 V was applied to generate glow discharge. This plasma treatment lasted for 5 minutes, creating pores and recesses on the fiber surface to facilitate the penetration of acetone vapor. The pretreated nanofibers were then placed in a sealed container, and acetone vapor was slowly introduced. By controlling the volume concentration of acetone vapor in the container to 10%, maintaining room temperature, and treating for 90 minutes, the nanofibers swelled under the influence of acetone. During this process, the acetone vapor interacted with the nanofiber surface, causing swelling and pores within the fibers. After the acetone vapor swelling treatment, the nanofibers were removed and dried. By controlling the drying temperature to 80℃ and the drying time to 5 hours, residual acetone vapor and solvent in the nanofibers are removed, thus fixing the fiber structure. After drying, further curing treatments such as heat treatment at 120℃ or chemical cross-linking are performed to enhance the mechanical properties and stability of the nanofibers. The prepared porous electrospun nanofiber biocarriers are then cleaned, disinfected, and post-treated to meet the needs of practical applications such as biological and cell fixation and carrier embedding. Finally, the performance of the porous electrospun nanofiber biocarriers is tested, including indicators such as pore size, pore distribution, specific surface area, and biocompatibility, to evaluate their quality and applicability.

[0024] Example 5 A method for preparing porous electrospun nanofiber biocarriers using an organic vapor swelling method involves first preparing polylactic acid particles and dissolving them in a mixed solution of dichloromethane and acetonitrile at a mass ratio of 10:1. Simultaneously, chloroform is prepared as an organic vapor source to promote the swelling of the nanofibers. Then, a 15% (w / w) electrospinning solution is injected into an electrospinning apparatus. The voltage is adjusted to 7000V, corresponding to a current of 0.01A, and the solution flow rate is 0.1mL / min. Electrospinning is then performed, resulting in an electrospun fiber membrane with a width of 50×50cm. 2The nanofibers were pretreated using surface plasma treatment. The nanofiber membrane was placed in a vacuum evaporator, first evacuated to 0.1 Pa, then a small amount of argon gas was introduced to 1 Pa, and a voltage of 2000 V was applied to generate glow discharge. This plasma treatment lasted for 5 minutes, creating pores and recessed structures on the fiber surface to facilitate the penetration of acetone vapor. The pretreated nanofibers were then placed in a sealed container, and chloroform vapor was slowly introduced. By controlling the volume concentration of chloroform vapor in the container to 1%, maintaining room temperature, and treating for 2 hours, the nanofibers swelled under the influence of chloroform. During this process, the chloroform vapor interacted with the nanofiber surface, causing swelling and pores within the fibers. After the chloroform vapor swelling treatment, the nanofibers were removed and dried. By controlling the drying temperature to 60℃ and the drying time to 3 hours, residual chloroform vapor and solvent in the nanofibers are removed, thus fixing the fiber structure. After drying, further curing treatments such as heat treatment at 120℃ or chemical cross-linking are performed to enhance the mechanical properties and stability of the nanofibers. The prepared porous electrospun nanofiber biocarriers are then cleaned, disinfected, and post-treated to meet the needs of practical applications such as biological and cell fixation and carrier embedding. Finally, the performance of the porous electrospun nanofiber biocarriers is tested, including indicators such as pore size, pore distribution, specific surface area, and biocompatibility, to evaluate their quality and applicability.

[0025] The specific embodiments described above are only used to illustrate the spirit of the present invention. The scope of protection of the present invention is not limited thereto. For those skilled in the art, other embodiments can be easily made by means of changes, substitutions or modifications based on the technical content disclosed in this specification. All such other embodiments should be covered within the scope of protection of the present invention.

Claims

1. A method for preparing porous electrospun nanofiber biocarriers using an organic vapor swelling method, characterized in that, Includes the following steps: Step 1: Dissolve a high-molecular-weight polymer with high spinnability and biocompatibility in a mixed solution of dichloromethane and acetonitrile to prepare an electrospinning solution; Step 2: Inject the electrospinning solution into the electrospinning equipment, adjust the voltage, current, and flow rate of the electrospinning solution, and perform the electrospinning operation; under the action of the electric field, the electrospinning solution forms a jet and is stretched and refined, and finally deposited on the collector to obtain a fiber membrane woven from smooth polymer nanofibers. Step 3: The smooth surface of the fiber membrane is pretreated by surface plasma treatment to create pores and a recessed structure on the surface of the fiber membrane to facilitate the penetration of organic vapors. Step 4: Place the pretreated fiber membrane in a sealed container, slowly introduce organic vapor, control the volume concentration of organic vapor in the container to be 1~10%, the treatment temperature to be room temperature, and the treatment time to be 10min~2h, so that the fiber membrane swells under the action of organic vapor. During this process, the organic vapor interacts with the surface of the nanofiber, causing swelling and pores to form inside the fiber membrane. Step 5: After organic vapor swelling treatment, the fiber membrane is taken out and dried; the drying temperature is controlled at 60℃~90℃ and the drying time is 3h~6h to remove the residual organic vapor and solvent in the fiber membrane and fix the fiber structure. After drying, the temperature is further raised to 120℃ for heat treatment to enhance the mechanical properties and stability of the nanofibers and obtain porous electrospun nanofiber biocarriers. Step 6: Clean and disinfect the prepared porous electrospun nanofiber biocarrier; finally, test the performance of the porous electrospun nanofiber biocarrier, including pore size, pore distribution, specific surface area, and biocompatibility, to evaluate its quality and applicability.

2. The method for preparing porous electrospun nanofiber biocarriers by organic vapor swelling according to claim 1, characterized in that, The high-spinnability and biocompatibility polymer mentioned in step 1 is nylon, polypropylene, polyethylene, polyethyl acetate or polylactic acid; the mass ratio of dichloromethane to acetonitrile in the mixed solution of dichloromethane and acetonitrile is 10:1 to 100:1; the mass concentration of the electrospinning solution is 10 to 15%.

3. The method for preparing porous electrospun nanofiber biocarriers by organic vapor swelling according to claim 1, characterized in that, The electrospinning equipment mentioned in step 2 is a high-voltage electrospinning equipment, with the voltage adjusted to 5000~20000V, the current to 0.01A~0.1A, and the electrospinning solution flow rate to 0.1mL / min~1mL / min.

4. The method for preparing porous electrospun nanofiber biocarriers by organic vapor swelling according to claim 1, characterized in that, The surface plasma treatment described in step 3 involves placing the fiber membrane in a vacuum evaporation apparatus, first evacuating it to 0.1 Pa, then introducing argon gas to 1 Pa, applying a voltage of 2000 V to generate glow discharge, and treating for 5 minutes.

5. The method for preparing porous electrospun nanofiber biocarriers by organic vapor swelling according to claim 1, characterized in that, The organic vapor mentioned in step 4 is acetone, methanol, or chloroform.

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