CN114767928A

CN114767928A - Preparation method of nerve conduit loaded with active particles with uniform concentration and nerve conduit

Info

Publication number: CN114767928A
Application number: CN202110086161.7A
Authority: CN
Inventors: 薛佳佳; 余逸玲; 龚博文; 张立群; 张馨丹
Original assignee: Beijing University of Chemical Technology
Current assignee: Beijing University of Chemical Technology
Priority date: 2021-01-22
Filing date: 2021-01-22
Publication date: 2022-07-22

Abstract

The invention discloses a preparation method of a nerve conduit loaded with active particles with uniform concentration and the nerve conduit. The method comprises the following steps: (1) adding degradable synthetic high molecular polymer or natural high molecular polymer and degradable synthetic high molecular polymer into a solvent A, and fully dissolving to obtain a solution A; (2) performing electrostatic spinning on the solution A by using a rolling roller as a receiver to obtain a fiber membrane with an oriented structure; (3) preparing a solution B and a solution C; (4) and (5) carrying out coaxial electrostatic spraying or uniaxial electrostatic spraying on the solution B and the solution C on the fiber membrane with the oriented structure, and curling the fiber membrane with the oriented structure to obtain the nerve conduit loaded with the active particles with uniform concentration. The nerve conduit of the present invention functions to promote axonal extension to promote peripheral nerve regeneration, and the nerve conduit may be degraded and replaced with new nerve or degraded and separated from the peripheral nerve surface after healing.

Description

Preparation method of nerve conduit loaded with active particles with uniform concentration and nerve conduit

Technical Field

The invention relates to the technical field of biological materials, in particular to a preparation method of a nerve conduit loaded with active particles with uniform concentration and the nerve conduit.

Background

The nerve conduit for bridging peripheral nerve injury used in the past is mainly made of non-degradable inert materials such as silicone tube, polyethylene, polyvinyl chloride, polytetrafluoroethylene and the like and is implanted into a human body to cause chronic foreign body reaction, complications such as inflammatory reaction, nerve fibrosis and the like are easily caused, the nerve conduit can be taken out only by secondary operation, the operation cost is high, and the nerve conduit is not beneficial to the body health of a patient. Therefore, the selection of degradable tissue engineering nerve conduits for repairing peripheral nerve injury is pressing day by day. The currently clinically available nerve conduit materials are mainly natural and artificially synthesized degradable high molecular polymer materials; compared with natural high molecular polymer, the artificially synthesized degradable high molecular polymer has low cost, easily obtained materials, no potential virus infection and the like. At present, the commonly used artificially synthesized degradable high molecular polymers, such as polylactic acid, polycaprolactone, polyglycolic acid and the like, are licensed by the U.S. food and drug administration.

At present, only ten degradable synthetic high molecular polymer materials can be used as a nerve conduit for clinical treatment of peripheral nerves, most of the degradable synthetic high molecular polymer materials are hollow conduits, and mainly play a role in guiding broken end bridging of damaged peripheral nerves and have no toxic degradation after repair is completed.

Extension of nerve axons and migration of cells are essential processes for repair of peripheral nerves, so guiding axons to extend from the proximal end to the distal end to create new axons can effectively help the recovery of peripheral nerve function. Therefore, increasing the extension of peripheral nerve axons and promoting the migration of nerve cells are necessary considerations in the design of neural tissue engineering scaffolds. Nerve growth factor has a profound effect on the regeneration of peripheral nerves, is expressed in large amounts upon peripheral nerve injury to support nerve cell survival and axon regeneration to repair peripheral nerve injury; but the neurotrophic factor has unstable chemical property, short in-vivo half-life, easy loss of activity and low effective release amount of biological functionality, is easy to generate toxic and side effects when being used excessively, and is not beneficial to repairing peripheral nerves; therefore, in order to make the neurotrophic factors effectively play a role in the peripheral nerve repair process, the neurotrophic factors need to be loaded in an effective carrier, so that the neurotrophic factors can protect the nerve growth factors, and the nerve growth factors can act on specific target cells to promote the repair and regeneration of peripheral nerves. In conclusion, the development of a loaded nerve conduit with high bioactivity and containing growth factors is very important for widening the application of the nerve conduit and improving the speed of repairing peripheral nerve injury.

Disclosure of Invention

In order to solve the problems in the prior art, the invention provides a preparation method of a nerve conduit loaded with active particles with uniform concentration and the nerve conduit. The invention constructs the electro-spinning fiber with an oriented structure as an outer layer, and combines the measures of taking active particles with uniform concentration as an inner layer (the inner layer is an electrostatic spraying layer loaded with an active particle core-shell structure with uniform concentration, the core layer contains growth factors, and the shell layer is a natural high molecular polymer) and the like to continuously release the required active particles from the nerve conduit; the outer layer is the electrospinning fiber with an oriented structure, and plays a role in recruiting Schwann cells; the active particles containing growth factors function to promote the migration of Schwann cells, the nerve conduits loaded with the active particles at a uniform concentration function to promote the extension of axons to promote the regeneration of peripheral nerves, and the nerve conduits can be degraded and replaced by new nerves or degraded and separated from the surface of the peripheral nerves after healing.

The hollow catheter is not a single synthetic high molecular polymer, but a synthetic high molecular polymer or a natural high molecular polymer and the synthetic high molecular polymer are used for improving the biological activity of the nerve catheter, and active particles are loaded to promote the repair rate of peripheral nerve injury.

One of the purposes of the invention is to provide a preparation method of a nerve conduit loaded with active particles with uniform concentration.

The method comprises the following steps:

adding degradable synthetic high molecular polymer or natural high molecular polymer and degradable synthetic high molecular polymer into a solvent A, and fully dissolving to obtain a solution A;

step (2), performing electrostatic spinning on the solution A by using a roller rotating at a high speed as a receiver to obtain a fiber membrane with an oriented structure;

step (3), adding a natural high molecular polymer into a solvent B to obtain a solution B; adding a growth factor into the solvent C to obtain a solution C;

step (4), taking the oriented fiber membrane obtained in the step (2) as a receiver, and performing coaxial electrostatic spraying by taking the solution B and the solution C as a shell layer and a core layer respectively, or performing uniaxial electrostatic spraying by mixing the solution B and the solution C to obtain an oriented structure fiber membrane with a single surface loaded with active particles with uniform concentration;

and (5) curling the oriented structure fiber membrane loaded with the active particles with uniform concentration on one side obtained in the step (4), wherein the active particle loaded side is an inner layer, and adhering the active particle loaded side with the solution A to form a tubular structure, so that the nerve conduit loaded with the active particles with uniform concentration is prepared.

In a preferred embodiment of the present invention,

step (1) of carrying out a treatment,

the solvent A is at least one selected from hexafluoroisopropanol, trifluoroethanol, trichloromethane, methanol, dichloromethane and N, N' -dimethylformamide;

the degradable synthetic high molecular polymer is selected from at least one of polylactic acid, polycaprolactone, polylactic acid-glycolic acid copolymer and polylactic acid-glycolic acid-caprolactone copolymer;

the natural high molecular polymer is at least one of collagen, gelatin, chitosan, starch, cellulose and elastin.

In a preferred embodiment of the present invention,

step (1), taking 1 part by weight of degradable synthetic high-molecular polymer as a reference, and taking 0-100 parts by weight of natural high-molecular material as a reference;

the mass concentration of the solution A is 6-20%, preferably 6-12%;

in a preferred embodiment of the present invention,

a step (2) of carrying out a treatment,

the solution A has the advancing speed of 0.1-10 mL/h, the voltage of 8-30 kV, the receiving distance of 10-25 cm and the roller rotating speed of 100-3000 rpm; the spinning time is 10-720 min.

In a preferred embodiment of the present invention,

step (3)

The solvent B is at least one selected from hydrochloric acid, acetic acid, ethyl acetate, glycerol, trifluoroethanol and hexafluoroisopropanol; and/or the presence of a gas in the atmosphere,

the solvent C is at least one selected from normal saline, ultrapure water, buffer solution, methanol and ethanol; and/or the presence of a gas in the atmosphere,

the growth factor is selected from at least one of nerve growth factor, vascular endothelial growth factor, brain-derived nerve growth factor, recombinant human acidic fibroblast growth factor and neurotrophic factor; and/or the presence of a gas in the gas,

In a preferred embodiment of the present invention,

the concentration range of the solution B is 1 mg/mL-200 mg/mL; preferably 10mg/mL to 50 mg/mL;

the concentration of the solution C is 10 ng/mL-10 mg/mL; preferably 100ng/mL to 1 mg/mL.

In a preferred embodiment of the present invention,

step (4) of carrying out a treatment,

the volume ratio of the shell layer solution to the core layer solution is 1: (0.2-0.6);

the dosage ratio of the fiber membrane of the oriented structure to the shell solution is 1g to 1g: (1-60) mL.

In a preferred embodiment of the present invention,

a step (4) of removing the solvent,

when the solution B and the solution C are sprayed coaxially, the volume ratio of the solution B to the solution C is 1: (0.1-1);

and when the single-axis spraying is carried out, the volume ratio of the solution B to the solution C is 1: (0.1-10);

the ratio of the fiber film of the oriented structure to the sum of the volumes of solution B and solution C was: 1g: (1-60 mL).

When the coaxial spraying is carried out, the advancing speed of the solution B electronic spraying solution is 0.1-10 mL/h, the advancing speed of the solution C electronic spraying solution is 0.1-5 mL/h, the voltage is 8-30 kV, the receiving distance is 8-30 cm, and the spraying time is 1-360 min;

during uniaxial spraying, the speed of the electric spraying solution after the solution B and the solution C are mixed is 2-10mL/h, the voltage is 8-30 kV, the receiving distance is 8-30 cm, and the spraying time is 1-360 min.

The second objective of the present invention is to provide a nerve conduit.

The nerve conduit is of a two-layer structure, and the outer layer is electrospun fibers of an oriented structure; the inner layer is a core-shell structure loaded with active particles and having uniform concentration.

In a preferred embodiment of the present invention,

the outer diameter of the nerve conduit is 0.5-3.0 mm.

The invention can adopt the following technical scheme:

the preparation method specifically comprises the following steps:

and (5) curling the oriented structure fiber membrane loaded with the active particles with uniform concentration on one side obtained in the step (4), wherein the active particle loaded side is an inner layer, and adhering the active particle loaded side by using the solution A to form a tubular structure, thus obtaining the nerve conduit loaded with the active particles with uniform concentration.

The nanofiber membrane obtained by electrostatic spraying needs to be still placed in a fume hood for airing for 2-3 days to remove the solvent.

Electrospinning of fibers has received much attention in the selection of the type of nerve conduit to be constructed, due to the properties of their extracellular matrix-like structures. Various materials can be prepared into the nerve conduit by the electrostatic spinning technology to be used for repairing peripheral nerve injury, such as natural high molecular polymers, such as collagen, gelatin, chitosan and the like, and synthetic high molecular polymers, such as polycaprolactone, polylactic acid, polyurethane and the like. The hollow conduit formed by the spinning fiber of the single polymer is often low in biological activity and few in biological active particles, and cannot well repair the damage of peripheral nerves, so that the key for improving the repair effect of the peripheral nerve damage and the current research hotspot are realized by regulating and controlling the surface topological structure and functionality of the spinning fiber, adding growth factor or drug-loaded medicine for promoting repair and realizing controllable release. In the aspect of regulating and controlling the topological structure of the fiber, the ordered oriented fiber can recruit cells through a surface contact induction effect, the shell layer in the core-shell structure is a natural high molecular polymer, which is beneficial to protecting growth factors or drug-loaded substances and promoting the migration of cells and the extension of axons, and the repair effect of peripheral nerve injury can be improved by constructing a specific rough structure or a patterned structure on the surface of a nerve conduit.

Drawings

FIG. 1 is an SEM photograph of 1mL/h oriented polycaprolactone fiber obtained in step (2) of example 1;

FIG. 2 is an SEM photograph of 5mL/h oriented polycaprolactone fiber obtained in step (2) of example 2.

Detailed Description

While the present invention will be described in detail and with reference to the specific embodiments thereof, it should be understood that the following detailed description is merely illustrative of the present invention and should not be taken as limiting the scope of the present invention, but is intended to cover modifications and variations thereof that would occur to those skilled in the art upon reading the present disclosure.

The starting materials used in the examples are all commercially available.

Example 1

Dissolving polycaprolactone into dichloromethane, and magnetically stirring at room temperature for 8 hours to obtain a solution A with the mass concentration of 12%;

step (2), carrying out electrostatic spinning by using the solution A, depositing the electrostatic spinning when a receiver of the electrostatic spinning is a roller with the rotating speed of 1200rpm, wherein the flow rate of the solution A is 1ml/h, the voltage is 18Kv, the receiving distance is 20cm, spinning is carried out for 360min, when the receiver of the electrostatic spinning is a roller with the rotating speed of 200rpm, the other conditions are the same, and the co-spinning time is 720min, so that the polycaprolactone fiber membrane with the uniaxial orientation structure is obtained;

dissolving collagen in an acetic acid aqueous solution, performing magnetic stirring at room temperature for 12 hours, and then fully mixing to obtain a 20mg/mL shell layer solution B, loading a 1mg/mL core layer solution C of a vascular endothelial growth factor dissolved in normal saline, and performing coaxial electrostatic spraying on the polycaprolactone fiber with the outer layer orientation structure obtained in the step (2), wherein the advancing rate of the shell layer electric spraying solution is 3mL/h, the advancing rate of the core layer electric spraying solution is 1mL/h, the voltage is 22kV, the receiving distance is 18cm, and the spraying is performed for 40min to obtain a nerve conduit loaded with active particles with uniform concentration so as to repair peripheral nerve injury; the volume ratio of the shell layer solution to the core layer solution is 1: 0.2, the dosage ratio of the fiber membrane of the oriented structure to the sum of the solution B and the solution C is as follows: 1g: 30 mL.

And (4) after the electrostatic spinning is finished, placing the membrane in a fume hood at room temperature for 3 days to fully volatilize the residual solvent.

And (5) curling the membrane, wherein one surface loaded with active particles is an inner layer, and adhering the inner layer with the solution A to form a tubular structure, so that the nerve conduit loaded with the active particles with uniform concentration is prepared, and the outer diameter of the nerve conduit is 0.6 mm.

Example 2

Dissolving polycaprolactone into hexafluoroisopropanol, and magnetically stirring at room temperature for 12 hours to obtain a solution A with the mass concentration of 10%;

step (2), carrying out electrostatic spinning by using the solution A, depositing the electrostatic spinning when a receiver of the electrostatic spinning is a roller with the rotating speed of 800rpm, wherein the flow rate of the solution A is 5ml/h, the voltage is 15Kv, the receiving distance is 15cm, spinning is carried out for 400min, when the receiver of the electrostatic spinning is the roller with the rotating speed of 100rpm, the co-spinning time is 800min under the same other conditions, and obtaining the polycaprolactone fiber film with the uniaxial orientation structure;

dissolving gelatin in an acetic acid aqueous solution, performing magnetic stirring at room temperature for 12 hours, then fully mixing to obtain a 30mg/mL solution B, loading a core layer 2mg/mL solution C of nerve growth factors dissolved in normal saline, and performing coaxial electrostatic spraying on the polycaprolactone fiber with the outer layer orientation structure obtained in the step (2), wherein the advancing speed of a shell layer electric spraying solution is 1.5mL/h, the advancing speed of a core layer electric spraying solution is 0.5mL/h, the voltage is 20kV, the receiving distance is 15cm, and spraying is performed for 35min to obtain a nerve conduit loaded with active particles with uniform concentration to repair peripheral nerve injury, and the volume ratio of the shell layer solution to the core layer solution is 1: 0.25; the dosage ratio of the fiber membrane of the oriented structure to the sum of the solution B and the solution C is as follows: 1g: 40 mL.

And (4) after electrostatic spinning is finished, placing the spinning membrane in a fume hood at room temperature for 3 days to fully volatilize the residual solvent.

And (5) curling the membrane, wherein one surface loaded with active particles is an inner layer, and adhering the inner layer with the solution A to form a tubular structure, so that the nerve conduit loaded with the active particles with uniform concentration is prepared, and the outer diameter of the nerve conduit is 0.8 mm.

Example 3

Step (1), dissolving polylactic acid in dichloromethane, and magnetically stirring at room temperature for 24 hours to obtain a solution A with the mass concentration of 10%;

step (2), carrying out electrostatic spinning by using the solution A, wherein when a receiver of the electrostatic spinning is a roller with the rotating speed of 1500rpm, the electrostatic spinning is carried out for deposition, the flow rate of the solution A is 2ml/h, the voltage is 18Kv, the receiving distance is 20cm, the spinning is carried out for 480min, when the receiver of the electrostatic spinning is a roller with the rotating speed of 150rpm, the other conditions are the same, and the co-spinning time is 960min, so that the polylactic acid fiber membrane with the uniaxial orientation structure is obtained;

and (3) dissolving collagen in an acetic acid aqueous solution, magnetically stirring at room temperature for 24 hours, and then fully mixing to obtain a 40mg/mL shell layer solution B, loading a 3mg/mL nuclear layer solution C of a nerve growth factor dissolved in deionized water, and spraying on the fiber of the outer layer oriented structure obtained in the step (2) by adopting coaxial electrostatic spraying, wherein the advancing speed of the shell layer electric spraying solution is 2mL/h, the advancing speed of the nuclear layer electric spraying solution is 0.4mL/h, the voltage is 25kV, the receiving distance is 30cm, and the spraying is 10min to obtain a nerve conduit loaded with active particles with uniform concentration to repair peripheral nerve injury, and the volume ratio of the shell layer solution to the nuclear layer solution is 1: 0.3; the dosage ratio of the fiber membrane of the oriented structure to the sum of the solution B and the solution C is as follows: 1g: 20 mL;

after electrostatic spinning is finished, placing the spinning membrane in a fume hood at room temperature for 3 days to fully volatilize residual solvent;

and (5) curling the membrane, wherein one surface loaded with active particles is an inner layer, and adhering the inner layer with the solution A to form a tubular structure so as to prepare the nerve conduit loaded with the active particles with uniform concentration, wherein the outer diameter of the nerve conduit is 1.0 mm.

Example 4

Step (1), dissolving polylactic acid in trifluoroethanol, and magnetically stirring at room temperature for 20 hours to obtain a solution A with the mass concentration of 12%;

step (2), performing electrostatic spinning by using the solution A, performing electrostatic spinning deposition when a receiver of the electrostatic spinning is a roller with the rotating speed of 2800rpm, wherein the flow rate of the solution A is 3ml/h, the voltage is 24Kv, the receiving distance is 20cm, spinning is performed for 420min, and when the receiver of the electrostatic spinning is a roller with the rotating speed of 180rpm, the co-spinning time is 840min under the same other conditions, so as to obtain the polymer fiber membrane with the uniaxial orientation structure;

dissolving gelatin in an acetic acid aqueous solution, performing magnetic stirring at room temperature for 12 hours, then fully mixing to obtain a 20mg/mL solution B, loading a brain-derived nerve growth factor and a recombinant human acidic fibroblast growth factor in a 4mg/mL nuclear layer solution C of deionized water, performing coaxial electrostatic spraying on the fibers of the outer-layer oriented structure obtained in the step (2), wherein the advancing speed of a shell-layer electric spraying solution is 4mL/h, the advancing speed of a nuclear-layer electric spraying solution is 2mL/h, the voltage is 22kV, the receiving distance is 15cm, and spraying is performed for 50min to obtain a nerve conduit loaded with active particles with uniform concentration so as to repair peripheral nerve injury, wherein the volume ratio of the shell-layer solution to the nuclear layer solution is 1: 0.4 of the total weight of the mixture; the dosage ratio of the fiber membrane of the oriented structure to the sum of the solution B and the solution C is as follows: 1g: 50 mL;

and (5) curling the membrane, wherein one surface loaded with active particles is an inner layer, and adhering the inner layer with the solution A to form a tubular structure so as to prepare the nerve conduit loaded with the active particles with uniform concentration, wherein the outer diameter of the nerve conduit is 1.25 mm.

Example 5

Step (1), dissolving a polylactic acid-glycolic acid copolymer in N, N' -dimethylformamide, and magnetically stirring at room temperature for 16 hours to obtain a solution A with the mass concentration of 11%;

step (2), carrying out electrostatic spinning by using the solution A, carrying out electrostatic spinning deposition when a receiver of the electrostatic spinning is a roller with the rotating speed of 2800rpm, wherein the flow rate of the solution A is 3ml/h, the voltage is 18Kv, the receiving distance is 20cm, the spinning time is 300min, and when the receiver of the electrostatic spinning is the roller with the rotating speed of 300rpm, the co-spinning time is 600min under the same other conditions, so as to obtain the polymer fiber membrane with the uniaxial orientation structure;

step (3), dissolving laminin and fibronectin in an acetic acid aqueous solution, performing magnetic stirring at room temperature for 16 hours, then fully mixing to obtain a 30mg/mL shell solution B, loading a 5mg/mL core solution C of a vascular endothelial growth factor dissolved in deionized water, and performing coaxial electrostatic spraying on the fibers of the outer-layer oriented structure obtained in the step (2), wherein the advancing rate of the shell electrospray solution is 5mL/h, the advancing rate of the core electrospray solution is 2.5mL/h, the voltage is 25kV, the receiving distance is 30cm, and the spraying time is 35min, so that the nerve conduit loaded with active particles with uniform concentration is obtained to repair peripheral nerve injury, and the volume ratio of the shell solution to the core solution is 1: 0.5; the dosage ratio of the fiber membrane of the oriented structure to the sum of the solution B and the solution C is as follows: 1g: 45 mL;

and (4) after the electrostatic spinning is finished, placing the spinning membrane in a fume hood at room temperature for 3 days to fully volatilize the residual solvent.

And (5) curling the membrane, wherein one surface loaded with active particles is an inner layer, and adhering the inner layer with the solution A to form a tubular structure, so that the nerve conduit loaded with the active particles with uniform concentration is prepared, and the outer diameter of the nerve conduit is 1.6 mm.

Example 6

Step (1), dissolving a polylactic acid-glycolic acid copolymer in N, N' -dimethylformamide, and magnetically stirring at room temperature for 24 hours to obtain a solution D with the mass concentration of 8%;

step (2), carrying out electrostatic spinning by using the solution A, carrying out electrostatic spinning deposition when a receiver of the electrostatic spinning is a roller with the rotating speed of 2000rpm, wherein the flow rate of the solution A is 2ml/h, the voltage is 12Kv, the receiving distance is 20cm, the spinning time is 250min, and when the receiver of the electrostatic spinning is a roller with the rotating speed of 250rpm, the co-spinning time is 500min under the same other conditions, so as to obtain the polymer fiber membrane with the uniaxial orientation structure;

and (3) dissolving laminin and fibronectin in an acetic acid aqueous solution, performing magnetic stirring at room temperature for 12 hours, then fully mixing to obtain a 10mg/mL solution B, loading a brain-derived nerve growth factor and a recombinant human acidic fibroblast growth factor in a 6mg/mL nuclear layer solution C of deionized water, performing coaxial electrostatic spraying on the fibers of the outer-layer oriented structure obtained in the step (2), wherein the propelling speed of a shell layer electrospraying solution is 1.5mL/h, the propelling speed of a nuclear layer electrospraying solution is 0.5mL/h, the voltage is 18kV, the receiving distance is 20cm, and spraying is performed for 30 minutes to obtain a nerve conduit loaded with active particles with uniform concentration so as to repair peripheral nerve injury, and the volume ratio of the shell layer solution to the nuclear layer solution is 1: 0.6; the dosage ratio of the fiber membrane of the oriented structure to the sum of the solution B and the solution C is as follows: 1g: 35 mL;

and (5) curling the membrane, wherein one surface loaded with active particles is an inner layer, and the inner layer is adhered by using the solution A to form a tubular structure, so that the nerve conduit loaded with the active particles with uniform concentration is prepared, and the outer radius of the nerve conduit is 1.5 mm.

Claims

1. A method of making a nerve conduit loaded with a uniform concentration of active particles, the method comprising:

2. The method of claim 1, wherein:

the preparation method comprises the following steps of (1),

the solvent A is at least one selected from hexafluoroisopropanol, trifluoroethanol, trichloromethane, methanol, dichloromethane and N, N' -dimethylformamide; and/or the presence of a gas in the gas,

the degradable synthetic high molecular polymer is selected from at least one of polylactic acid, polycaprolactone, polylactic acid-glycolic acid copolymer and polylactic acid-glycolic acid-caprolactone copolymer; and/or the presence of a gas in the gas,

3. The method of claim 1, wherein:

step (1), the amount of the natural high molecular material is 0-100 parts by weight based on 1 part by weight of the degradable synthetic high molecular polymer; and/or the presence of a gas in the gas,

the mass concentration of the solution A is 6-20%; preferably 6 to 12%.

4. The method of claim 1, wherein:

a step (2) of removing the solvent,

5. The method of claim 1, wherein:

step (3)

The solvent B is at least one selected from hydrochloric acid, acetic acid, ethyl acetate, glycerol, trifluoroethanol and hexafluoroisopropanol; and/or the presence of a gas in the gas,

6. The method of claim 5, wherein:

7. The method of claim 1, wherein:

step (4) of carrying out a treatment,

when the single-shaft spraying is carried out, the volume ratio of the solution B to the solution C is 1: (0.1-10);

8. The method of claim 7, wherein:

a step (4) of removing the solvent,

9. A nerve conduit obtainable by the method of any one of claims 1 to 8, wherein:

the nerve conduit is of a two-layer structure, and the outer layer is electrospun fibers of an oriented structure; the inner layer is an electrostatic spray layer loaded with active particles with uniform concentration.

10. A nerve conduit according to claim 9, wherein:

the outer diameter range of the nerve conduit is as follows: 0.5-3.0 mm.