Preparation method of hemostatic breathable bacteria-isolating nanofiber membrane, hemostatic breathable bacteria-isolating nanofiber membrane and hemostatic breathable bacteria-isolating dressing

Abstract

The application relates to a preparation method of a hemostatic, breathable and bacteria-isolating nanofiber membrane, the hemostatic, breathable and bacteria-isolating nanofiber membrane and a hemostatic, breathable and bacteria-isolating dressing. The preparation steps are as follows: a spinning solution A is prepared by adding a hydrophobic polymer into a solvent A; a spinning solution B is obtained by adding a conductivity regulator and a hydrophobic polymer into a solvent B; an outer layer nanofiber membrane is prepared by electrospinning the spinning solution A; a fiber prepared by electrospinning the spinning solution B is received on the outer layer nanofiber membrane to form an inner layer nanofiber membrane; a composite fiber membrane formed by the outer layer nanofiber membrane and the inner layer nanofiber membrane is the composite fiber membrane; a hemostatic agent solution is sprayed on the composite fiber membrane to prepare the hemostatic, breathable and bacteria-isolating nanofiber membrane. The hemostatic, breathable and bacteria-isolating nanofiber membrane can achieve hemostasis, breathability and bacteria isolation, has good wound exudate discharge performance, has no stimulation to a wound, is not easy to be damaged, has no fragment residue during dressing change, has a simple process and is suitable for industrial production.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of medical wound care, and further relates to a preparation method of a hemostatic, breathable and bacteria-isolating nanofiber membrane, the hemostatic, breathable and bacteria-isolating nanofiber membrane, and a hemostatic, breathable and bacteria-isolating dressing. BACKGROUND

[0002] Medical dressing refers to a medical material used to cover sores, wounds or other damaged surfaces, and mainly plays a role in protecting wounds and promoting wound healing. Traditional dressings are mainly gauze, bandage, cotton yarn, adhesive bandage and the like, and can only play a role in protecting wounds. Existing medical dressings have many problems, such as being unable to prevent water, affecting the normal life of patients, adhering to wounds, being unable to block external bacterial infection, having poor wound compliance, being difficult to adhere to wounds in motion parts, and being unable to promote wound healing.

[0003] In view of the above shortcomings, some dressings use polyurethane semi-permeable membranes and polyethylene microporous membranes as the outer layer of the dressing, which have good waterproof performance and bacterial barrier property, but the polyurethane semi-permeable membrane is not conducive to wound healing and also not conducive to the discharge of wound exudate. Some dressings add antibacterial agents (such as silver ions) to prevent wound infection, but have the problem of drug resistance, and silver ions have cytotoxicity and can damage organs such as the liver of the human body.

[0004] Therefore, the above-mentioned dressings have the problem that waterproof performance, bacterial barrier property and air permeability cannot be considered, and it is necessary to develop a medical dressing which has good wound exudate discharge and effectively blocks external bacterial infection.

[0005] In addition, the demand for hemostatic dressings is also relatively high, and effective hemostasis is a major problem that needs to be solved urgently in surgical operations and trauma. Chitosan is the only cationic polysaccharide in nature, has low allergenicity and natural antibacterial property, can quickly stop bleeding, and is therefore particularly suitable for use in battlefield first aid; in addition, chitosan also has biocompatibility, can be degraded and absorbed in the body, promotes wound healing, reduces the production of scars, and has anti-inflammatory effect, and therefore has great advantages in the application of hemostatic, antibacterial and wound repair dressings.

[0006] In summary, it is of great market application prospect to develop a medical dressing which has good wound exudate discharge, good air permeability, effectively blocks external bacterial infection, and has the function of quickly stopping bleeding. SUMMARY

[0007] To solve the problems in the prior art, the application provides a preparation method of a hemostatic, breathable and bacteria-isolating nanofiber membrane, the hemostatic, breathable and bacteria-isolating nanofiber membrane and a hemostatic, breathable and bacteria-isolating dressing. The hemostatic, breathable and bacteria-isolating nanofiber membrane and the breathable and bacteria-isolating dressing prepared by using the same can achieve hemostasis, breathability and bacteria isolation, the wound exudate is easily discharged, the dressing is not easy to be damaged and has no residue when changed, the process is simple and the dressing is suitable for industrial production.

[0008] One of the purposes of the application is to provide a preparation method of a hemostatic, breathable and bacteria-isolating nanofiber membrane, which comprises the following steps:

[0009] (1) Preparation of spinning solution A: hydrophobic polymer is added to solvent A and dissolved to prepare spinning solution A;

[0010] (2) Preparation of spinning solution B: conductivity regulator and hydrophobic polymer are added to solvent B and dissolved to obtain spinning solution B;

[0011] (3) Preparation of outer layer nanofiber membrane: spinning solution A is electrospun to prepare the outer layer nanofiber membrane;

[0012] (4) Preparation of composite fiber membrane: the fiber prepared by electrospinning of spinning solution B is received on the outer layer nanofiber membrane to form the inner layer nanofiber membrane; the outer layer nanofiber membrane and the inner layer nanofiber membrane form the composite fiber membrane;

[0013] (5) Preparation of hemostatic agent solution: hemostatic agent is added to solvent C and dissolved to prepare the hemostatic agent solution;

[0014] (6) Preparation of hemostatic, breathable and bacteria-isolating nanofiber membrane: the hemostatic agent solution is loaded on the inner layer nanofiber membrane of the composite fiber membrane to prepare the hemostatic, breathable and bacteria-isolating nanofiber membrane;

[0015] The solvent A is a mixed solvent, which is preferably a mixed solvent formed by an organic solvent with a boiling point greater than 100 DEG C and a solvent with a boiling point of 100 DEG C or below;

[0016] The solvent B is selected from one or a combination of organic solvents with a boiling point greater than 100 DEG C;

[0017] The solvent C is selected from one or a combination of formic acid, acetic acid, trifluoroacetic acid, lactic acid, hydrochloric acid, hexafluoroisopropanol or water.

[0018] In the application, the solvent C includes but is not limited to the above-mentioned solvents, and the solvents commonly used in the prior art and capable of dissolving the hemostatic agent are also within the optional range of the application.

[0019] In the present invention, the means for achieving sufficient dissolution in steps (1), (2) and / or (5) adopt conventional technical means in the prior art, such as one or a combination of other means such as stirring and heating; there are no special requirements for the heating temperature and stirring speed, as long as the purpose of sufficient dissolution can be achieved.

[0020] In the present invention, except for temperature and humidity, the other spinning process parameters of electrospinning are selected by referring to existing conventional process parameters or obtained by adjusting conventional process parameters. The preferred spinning process parameters for the outer nanofiber membrane are: spinning voltage 14-20KV, spinning distance 15-20cm, spinning rate 0.5-1.5ml / h;

[0021] The spinning process parameters of the inner layer nanofiber membrane are: spinning voltage 13-17KV, spinning distance 10-16cm, and spinning rate 0.5-2ml / h.

[0022] Preferably,

[0023] In the solvent A or solvent B, the organic solvent having a boiling point greater than 100° C. is the same or different and is independently selected from one or a combination of dimethylformamide, dimethylacetamide, dimethyl sulfoxide, dioxane, octane, toluene, formic acid, acetic acid, formamide, acetamide, butyl acetate, ethylene glycol, propylene glycol, butanol, cyclohexanone, cyclopentanone or N-methylpyrrolidone;

[0024] In the present invention, the organic solvent having a boiling point greater than 100° C. includes but is not limited to the above-mentioned solvents. The currently commonly used organic solvents within this boiling point range are also within the optional scope of the present invention.

[0025] In the solvent A, the solvent having a boiling point of 100° C. or below is selected from one or a combination of tetrahydrofuran, acetone, chloroform, dichloromethane, trichloroethane, acetonitrile, n-hexane, cyclohexane, ether, methanol, ethanol, propanol, trifluoroethanol, hexafluoroisopropanol, ethyl acetate, trifluoroacetic acid, methyl ethyl ketone or water; and / or,

[0026] In the present invention, solvents with a boiling point of 100°C or below include but are not limited to the above solvents. Organic solvents commonly used in this boiling point range are also within the optional scope of the present invention.

[0027] In the solvent A, the mass ratio of the organic solvent with a boiling point greater than 100° C. to the solvent with a boiling point of 100° C. or less is 0.5 to 9:1.

[0028] Preferably,

[0029] The hydrophobic polymer in the spinning solution A and the spinning solution B is the same or different, and each is independently selected from one or a combination of polyurethane, polycaprolactone silk fibroin, polyvinyl chloride, polystyrene, polyamide, polyhydroxybutyrate, polybutylene succinate, polybutylene adipate / terephthalate, polyethylene terephthalate or polycarbonate; and / or,

[0030] In the present application, the hydrophobic polymer includes but is not limited to the above-mentioned substance categories, and the hydrophobic polymer commonly used in the prior art is also within the optional range of the present application;

[0031] The hemostatic agent includes but is not limited to chitosan, and other materials with hemostatic function in the prior art are also within the optional range of the present application; and / or,

[0032] The solvent C further includes a solvent D;

[0033] The solvent D is selected from one or a combination of dimethylformamide, dimethylacetamide, dimethyl sulfoxide, dioxane, toluene, formamide, acetamide, butyl acetate, cyclohexanone, cyclopentanone, tetrahydrofuran, acetone, chloroform, dichloromethane, trichloroethane, acetonitrile, trifluoroethanol, ethyl acetate, methyl ethyl ketone or N-methyl pyrrolidone;

[0034] The volume percentage content of the solvent D in the solvent C is 1% to 10%.

[0035] The addition of the solvent D can make the hemostatic agent better adhere to the surface of the nanofiber, and at the same time, the solvent D can also partially dissolve the surface of the composite fiber membrane, so as to enhance the adhesion between the hemostatic agent and the fiber.

[0036] Preferably,

[0037] In the spinning solution A,

[0038] The concentration of the hydrophobic polymer is 12wt% to 25wt%; more preferably, 14wt% to 25wt%; and / or,

[0039] In the spinning solution B,

[0040] The concentration of the hydrophobic polymer is 6wt% to 12wt%; more preferably, 6wt% to 10wt%; and / or, the concentration of the conductivity regulator is 0.0.001wt% to 3wt%, preferably, 0.01wt% to 1wt%; and / or,

[0041] In the hemostatic agent solution,

[0042] The concentration of the hemostatic agent is 1wt% to 10wt%.

[0043] Preferably,

[0044] The conductivity regulator is selected from one or a combination of inorganic salt, ionic surfactant, quaternary ammonium salt, water, hydrochloric acid or acetic acid.

[0045] More preferably,

[0046] The inorganic salt is selected from one or a combination of sodium chloride or lithium chloride; and / or,

[0047] The ionic surfactant is selected from one or a combination of sodium dodecyl benzene sulfonate or sodium dodecyl sulfonate; and / or,

[0048] The quaternary ammonium salt is selected from one or a combination of dimethyloctadecyl [3- (trimethoxysilyl) propyl] ammonium chloride, alkyl dimethyl benzyl ammonium chloride or octyl decyl dimethyl ammonium chloride.

[0049] Preferably,

[0050] The spinning temperature of electrospinning in step (3) is above 10℃, and the spinning humidity is above 10%; and / or,

[0051] The spinning temperature of electrospinning in step (4) is above 30℃, and the spinning humidity is above 40%; and / or,

[0052] In step (6), the loading method is spraying method; and / or,

[0053] Preferably,

[0054] The spinning temperature of electrospinning in step (3) is 10-30℃, and the spinning humidity is 10%-50%;

[0055] The spinning temperature of electrospinning in step (4) is 30-50℃, and the spinning humidity is 40%-90%;

[0056] In step (6), the loading method is electrostatic spraying method.

[0057] In the present application, the spraying method can adopt the spraying method in the prior art, such as electrostatic spraying method, etc.; the process parameters of spraying can be selected according to the conventional process parameters or obtained by adjusting the conventional process parameters, so as to effectively load the hemostatic agent on the composite fiber membrane; more preferably, the voltage of electrostatic spraying is 10-30KV, the solution extrusion rate is 0.5-2mL / h, the environmental temperature is 20-40℃, and the humidity is 10%-40%.

[0058] In the present application, when the hemostatic agent solution is sprayed on the composite fiber membrane, the inner layer nanofiber membrane of the composite fiber membrane is sprayed, because the inner layer fiber membrane is the side that adheres to the wound, and the hemostatic agent is more loaded on the inner layer fiber membrane, which is more conducive to hemostasis.

[0059] In the present application, the electrostatic spraying method uses less hemostatic agent, the hemostatic agent dries quickly on the inner layer of the fiber membrane and does not penetrate to the outer layer of the fiber membrane, compared with the direct solution coating method, the electrostatic spraying method can avoid waste of hemostatic agent and reduce cost.

[0060] The second object of the present application is to provide a hemostatic, breathable and bacteria-proof nanofiber membrane prepared by the preparation method of the first object of the present application, wherein the hemostatic, breathable and bacteria-proof nanofiber membrane comprises a composite fiber membrane and a hemostatic agent.

[0061] The content of the hemostatic agent is 0.1wt%-2wt% based on the total weight of the hemostatic, breathable and bacteria-proof nanofiber membrane being 100%;

[0062] The average pore size between the fibers in the outer layer nanofiber membrane is larger than the average pore size between the fibers in the inner layer nanofiber membrane.

[0063] Preferably,

[0064] In the composite fiber membrane,

[0065] The average fiber diameter of the outer layer nanofiber membrane is 350-800nm, the average pore size between the fibers is 400-800nm, and the thickness is 10-200 microns; preferably, the average fiber diameter of the outer layer nanofiber membrane is 500-800nm, the average pore size between the fibers is 500-800nm;

[0066] The average fiber diameter of the inner layer nanofiber membrane is 50-300nm, the average pore size between the fibers is 50-300nm, and the thickness is 10-200 microns; preferably, the average fiber diameter of the inner layer nanofiber membrane is 50-100nm, the average pore size between the fibers is 50-200nm;

[0067] The fibers in the inner layer nanofiber membrane are adhered to each other at the overlapping points.

[0068] The third object of the present application is to provide a hemostatic, breathable and bacteria-proof dressing prepared from the hemostatic, breathable and bacteria-proof nanofiber membrane of the second object of the present application.

[0069] Invention principle:

[0070] The outer layer nanofiber membrane of the application adopts two kinds of solvents with low boiling point and high boiling point, the low boiling point solvent is more volatile in the spinning process, compared with using only high boiling point solvent, the fiber diameter formed in the outer layer nanofiber membrane is relatively thick, and the pore size is also relatively large. The inner layer nanofiber membrane only uses high boiling point solvent, and the prepared nanofiber is thin, and the pore size is also small. In the preparation process of the inner layer nanofiber membrane, the spinning temperature is high, the high temperature can ensure that the residual solvent is completely volatilized, so that the fibers are not dissolved and adhered to each other. The pore size of the outer layer nanofiber membrane is large, and the pore size of the inner layer nanofiber membrane is small. When forming a medical dressing, the inner layer nanofiber membrane faces the wound, and the outer layer nanofiber membrane is on the upper part of the inner layer nanofiber membrane. The inner and outer layers of the nanofiber membrane form a conical communication hole similar to a capillary effect. Since it is a hydrophobic nanofiber material, the capillary effect can be used. The additional pressure of the inner layer nanofiber membrane is larger, and the additional pressure of the outer layer nanofiber membrane is smaller, so as to discharge the wound permeate liquid to the outside, form a one-way water permeation, and improve the water resistance.

[0071] The humidity commonly used in electrospinning is 20-40%, high humidity is not conducive to solvent volatilization, and residual solvent can easily cause fiber collapse, fiber adhesion together, and poor fiber diameter uniformity. The inner layer nanofiber membrane of the application is spun by high boiling point solvent, which can inhibit the volatilization speed of the solvent in a high humidity environment, so that the fibers adhere to each other. At the same time, increasing the spinning temperature can also avoid excessive residual solvent, which can cause fiber collapse and adhesion, so that only the overlapping points of the fibers in the inner layer nanofiber membrane adhere to each other. The addition of conductivity regulator can improve the conductivity and reduce the fiber diameter in cooperation with other components to improve the fiber uniformity. The water and normal saline in the conductivity regulator volatilize during the spinning process, and the residues are harmless to the human body.

[0072] Compared with the prior art, the application has the following advantages:

[0073] The hemostatic, breathable and bacteria-blocking nanofiber membrane of the application can not only stop bleeding, but also block bacteria to prevent wound infection, with a bacteria blocking rate of 100%, and high air permeability, with a non-contact steam permeability of up to 8253 / (m 2 ·24h), while the commercially available Hualituo film dressing has a non-contact steam permeability of only 1260g / (m 2 ·24h); and meets the water resistance requirements of medical dressings;

[0074] The composite fiber membrane in the hemostatic breathable bacteria-isolating nanofiber membrane of the present application can make the tensile capacity of the thinner fibers increase after the inner layer fibers adhere to each other, and the fibers of the inner layer fiber membrane of the present application have adhesion points and higher tensile strength than the fibers that are just overlapped together without adhesion points; the fibers of the outer layer fiber membrane of the present application are thicker and have higher strength; meanwhile, the fibers of the inner layer fiber membrane of the present application have residual solvent that can adhere to the outer layer fibers to form a composite fiber membrane with higher overall strength and less possibility of being separated into layers. When used, the composite fiber membrane of the present application is less likely to be separated into layers, less likely to be damaged by friction and lose the barrier effect, and less likely to be left on the surface of a wound during dressing change, thus causing inflammation of the tissue.

[0075] The composite fiber membrane in the hemostatic breathable bacteria-isolating nanofiber membrane of the present application has a structure of two layers of nanofiber membranes, the outer layer nanofiber membrane has a large pore size, the inner layer nanofiber membrane has a small pore size, and the two layers of nanofiber membranes form tapered communication holes. By utilizing the capillary effect, the additional pressure of the inner layer nanofiber membrane is large, and the additional pressure of the outer layer nanofiber membrane is small, so that water is discharged from the inside to the outside, forming unidirectional water permeation, and thus improving the water barrier performance.

[0076] The nanofiber membrane prepared by electrospinning is formed by random accumulation of nanofibers, the pores formed by the interweaving of the fibers are of uneven size, and during industrial production, the nanofiber membrane may have local defects. If a single membrane is used, it is basically impossible to achieve 100% bacterial barrier. The present application uses two layers of nanofiber membranes with gradient pore sizes to form a composite, which can ensure that the pore size of the composite fiber membrane is completely less than 500 nm (the size of bacteria is about 0.5-6 microns), and can also eliminate the influence of local defects, ensuring that the composite fiber membrane has 100% bacterial barrier, meeting the requirement of medical dressing bacteria barrier performance (national standard requires that medical dressing bacteria barrier performance must have 100% bacterial barrier).

[0077] The hemostatic breathable bacteria-isolating nanofiber membrane of the present application is formed by introducing chitosan onto the composite fiber membrane. The polycation of chitosan combines with the anion on the surface of the membrane of red blood cells to make the red blood cells agglomerate, and at the same time, activates the aggregation of platelets, activates thrombin, so as to achieve the purpose of rapid hemostasis; at the same time, chitosan can form a gel layer on the bleeding wound surface to protect the wound surface; finally, chitosan has antibacterial function, which cooperates with the breathable bacteria-isolating composite fiber membrane to not only remove bacteria on the wound surface and prevent wound infection, but also prevent external bacteria from invading the wound.

[0078] The hemostatic breathable bacteria-isolating nanofiber membrane of the present application has no irritation to the wound, simple process, and is suitable for industrial production. BRIEF DESCRIPTION OF DRAWINGS

[0079] Figure 1 SEM image of the composite fiber membrane prepared for Example 4 of the present application;

[0080] Figure 2 SEM image of the composite fiber membrane prepared for Comparative Example 2 of the present application;

[0081] Figure 3 SEM image of the composite fiber membrane prepared for Example 1 of the present application;

[0082] Figure 4 SEM image of the hemostatic and breathable and bacteria-proof nanofiber membrane prepared for Example 1 of the present application;

[0083] Figure 5 Structural schematic diagram of the hemostatic and breathable and bacteria-proof dressing of the present application.

[0084] Explanation of reference signs:

[0085] 1 - release paper, 2 - adhesive layer, 3 - hemostatic and breathable and bacteria-proof nanofiber membrane. DETAILED DESCRIPTION

[0086] The present application will be described in detail below in conjunction with specific drawings and examples. It is necessary to point out here that the following examples are only used to further illustrate the present application and cannot be understood as limiting the protection scope of the present application. Some non-essential improvements and adjustments of the present application made by those skilled in the art according to the content of the present application still fall within the protection scope of the present application.

[0087] Source of raw materials:

[0088] The raw materials used in the present application are all conventional commercially available products.

[0089] Test method:

[0090] The bacteria-proof experiment refers to the test method in Medical Standard YY / T 0471.5-2017 Test Method for Contact Wound Dressings Part 5: Bacterial Barrier.

[0091] The water vapor transmission rate test refers to the test method in YY / T 0471.2-2004 Test Method for Contact Wound Dressings Part 2: Water Vapor Transmission Rate of Breathable Film Dressings.

[0092] The waterproof performance refers to the test method in YY / T 0471.3-2004 Test Method for Contact Wound Dressings Part 3: Water Resistance.

[0093] The mechanical property refers to GB / T 1040.3-2006 Determination of Tensile Properties of Plastics Part 3: Test Conditions for Thin Plastic and Sheet.

[0094] The hemostatic property refers to the test method in YY / T 1477.5-2020 Standard Test Model for Performance Evaluation of Contact Wound Dressings Part 5: In Vitro Model for Evaluating Hemostatic Performance.

[0095] Example 1

[0096] The preparation method of the hemostatic, breathable and bacteria-isolating nanofiber membrane comprises the following steps:

[0097] First, polyurethane is added in a mixed solvent of dimethylformamide and tetrahydrofuran with a mass ratio of 2:1, and stirred and dissolved at 60℃ for 12 hours to prepare a spinning solution A, and the concentration of polyurethane in the spinning solution A is 18wt%;

[0098] Then, sodium chloride is added in a dimethylformamide solvent, and after stirring, polyurethane is added, and stirred and dissolved at 60℃ for 12 hours to prepare a spinning solution B, and in the spinning solution B, the concentration of sodium chloride is 0.05wt%, and the concentration of polyurethane is 10wt%.

[0099] First, the spinning solution A is added to the electrospinning equipment to perform electrospinning to prepare an outer layer nanofiber membrane, and the spinning parameters of the outer layer nanofiber membrane are: spinning temperature 20℃, humidity 20%, spinning voltage 15KV, spinning distance 15cm, and spinning rate 1ml / h; then the spinning solution B is added to the electrospinning equipment to continue spinning on the outer layer nanofiber membrane to prepare an inner layer nanofiber membrane, and the double-layer nanofiber membrane, i.e. the composite fiber membrane (the specific structure is shown in Figure 3 The spinning parameters of the inner layer nanofiber membrane are: spinning temperature 30℃, humidity 40%, spinning voltage 17KV, spinning distance 15cm, and spinning rate 1ml / h.

[0100] In the composite fiber membrane prepared by the above method, the outer layer nanofiber membrane has a thickness of 100 microns, the average diameter of the nanofiber is 500nm, and the average pore size between the fibers is 550nm; the inner layer nanofiber membrane has a thickness of 100 microns, the average diameter of the fiber is 200nm, and the average pore size between the fibers is 200nm, and in the inner layer nanofiber membrane, the fiber overlap points are adhered to each other and adhered to the outer layer fiber.

[0101] The composite fiber membrane can 100% block the penetration of bacteria, meeting the requirements of medical dressings. The water vapor transmission rate thereof is 7202g / (m 2 ·24h); it can withstand 500mm of hydrostatic pressure for 3 minutes, meeting the water resistance requirements of medical dressings; the tensile strength of the composite fiber membrane is 13MPa, and the hemostatic performance test result thereof is an average flow rate reduction of 0.002μg / s 2 .

[0102] A hemostatic agent solution with a concentration of 3wt% is prepared by adding chitosan into acetic acid and fully dissolving; and the hemostatic agent solution is sprayed on the inner layer nanofiber membrane of the above composite fiber membrane by electrostatic spraying (i.e. the hemostatic agent solution is sprayed towards the inner layer nanofiber membrane), to prepare a hemostatic, breathable and bacteria-isolating nanofiber membrane (the specific structure is shown in Figure 4Electrospinning voltage 15KV, solution propelling rate 1mL / h, ambient temperature 25℃, humidity 20%.

[0103] The hemostatic and bacteria-proof nanofiber membrane prepared by the above method comprises the composite fiber membrane and the hemostatic agent; the content of the hemostatic agent is 0.5wt% based on the total weight of the hemostatic and bacteria-proof nanofiber membrane.

[0104] The hemostatic and bacteria-proof nanofiber membrane can also 100% block the penetration of bacteria, meeting the requirements of medical dressings. The water vapor transmission rate thereof is 6986 / (m 2 ·24h); it can withstand 500mm of hydrostatic pressure for 3min, meeting the water resistance requirements of medical dressings; the hemostatic performance test result is an average flow rate reduction of 0.01μg / s 2 ; the tensile strength of the hemostatic and bacteria-proof nanofiber membrane is 13MPa.

[0105] As can be seen from the experimental results of Example 1, the hemostatic and bacteria-proof nanofiber membrane of the present application has a hemostatic agent in addition to the composite fiber membrane. The introduction of the hemostatic agent can significantly improve the hemostatic performance, but will slightly reduce the water vapor transmission rate and has no effect on the tensile strength of the composite fiber membrane. Overall, the present application first prepares a composite fiber membrane with good air-permeable and bacteria-proof effects, and then introduces a layer of hemostatic agent on the composite fiber membrane to form a hemostatic and bacteria-proof nanofiber membrane, which has good hemostatic, air-permeable and bacteria-proof performance and fully meets the use requirements of medical dressings.

[0106] From Figure 3 and Figure 4 comparison, it can be seen that, Figure 4 relative to Figure 3 , there is some granular hemostatic agent on the fibers.

[0107] Example 2

[0108] The preparation method thereof is the same as that of the hemostatic and bacteria-proof nanofiber membrane of Example 1, and the only difference is that:

[0109] The solvent in the hemostatic agent solution is a mixed solvent, and the mixed solvent is acetic acid and dimethylformamide, and the volume percentage content of dimethylformamide in the above mixed solvent is 2%.

[0110] The hemostatic and bacteria-proof nanofiber membrane prepared by the above method comprises the composite fiber membrane and the hemostatic agent; the content of the hemostatic agent is 0.52wt% based on the total weight of the hemostatic and bacteria-proof nanofiber membrane.

[0111] The hemostatic and bacteria-proof nanofiber membrane can also 100% block the penetration of bacteria, meeting the requirements of medical dressings. The water vapor transmission rate thereof is 7001g / (m 2·24h); can withstand 500mm of hydrostatic pressure for 3min, meeting the water resistance requirement of medical dressings; the average flow rate reduction of the hemostatic performance test is 0.011μg / s 2 The tensile strength of the hemostatic and air-permeable and bacteria-proof nanofiber membrane is 12.8MPa.

[0112] It can be seen from the comparison between Example 1 and Example 2 of the present application that when the solvent of the hemostatic agent is a mixed solvent, dimethylformamide (i.e., solvent D) partially dissolves the surface of the composite fiber membrane, thereby better bonding the hemostatic agent and the fibers, but slightly reducing the tensile strength of the composite fiber membrane.

[0113] Example 3

[0114] The preparation method of the hemostatic and air-permeable and bacteria-proof nanofiber membrane comprises the following steps:

[0115] First, polyethylene terephthalate is added in a mixed solvent with a mass ratio of dimethylformamide: trifluoroethanol = 1:2, and stirred and dissolved for 12h to prepare spinning solution A, in which the concentration of polyethylene terephthalate is 14wt%;

[0116] Then, acetic acid is added in a toluene solvent, and after stirring, polycaprolactone is added, and stirred and dissolved for 12h to prepare spinning solution B, in which the concentration of acetic acid is 0.001wt%, and the concentration of polycaprolactone is 6wt%.

[0117] First, spinning solution A is added to an electrospinning device to perform electrospinning to prepare an outer layer nanofiber membrane; the spinning parameters of the outer layer nanofiber membrane are: spinning temperature 30℃, humidity 50%, spinning voltage 14KV, spinning distance 15cm, and spinning rate 1.2ml / h.

[0118] Then, spinning solution B is added to the electrospinning device to continue spinning on the outer layer nanofiber membrane to prepare an inner layer nanofiber membrane, and the double-layer nanofiber membrane is the composite fiber membrane. The spinning parameters of the inner layer nanofiber membrane are: spinning temperature 40℃, humidity 60%, spinning voltage 13KV, spinning distance 10cm, and spinning rate 1.5ml / h.

[0119] In the composite fiber membrane prepared by the above method, the outer layer nanofiber membrane has a thickness of 200 microns, an average fiber diameter of 600nm, and an average pore size between fibers of 650nm; the inner layer nanofiber membrane has a thickness of 200 microns, an average fiber diameter of 300nm, and an average pore size between fibers of 300nm, and the fibers in the inner layer nanofiber membrane are adhered to each other and to the outer layer fibers.

[0120] The composite fiber membrane can 100% block bacteria penetration, meeting the requirements of medical dressings. Its water vapor transmission rate is 8365g / (m2 • 24h). It can resist 500mm hydrostatic pressure for 3min, which meets the requirement of water resistance of medical dressing; the tensile strength of the composite fiber membrane is 10MPa.

[0121] The mixed solvent of trifluoroacetic acid and toluene is configured, the volume percentage of toluene in the mixed solvent is 5%, and chitosan is added to the mixed solvent to be fully dissolved, thereby preparing a hemostatic agent solution with a concentration of 1wt%; the hemostatic agent solution is sprayed on the inner layer nanofiber membrane of the composite fiber membrane by an electrostatic spraying method, thereby preparing a hemostatic, breathable and bacteria-proof nanofiber membrane; the electrostatic spraying voltage is 10KV, the solution extrusion rate is 0.5mL / h, the environmental temperature is 30℃, and the humidity is 30%.

[0122] The hemostatic, breathable and bacteria-proof nanofiber membrane prepared by the above method comprises a composite fiber membrane and a hemostatic agent; the content of the hemostatic agent is 0.1wt% based on the total weight of the hemostatic, breathable and bacteria-proof nanofiber membrane.

[0123] The hemostatic, breathable and bacteria-proof nanofiber membrane can also block 100% of bacteria penetration, which meets the requirement of medical dressing. The water vapor transmission rate thereof is 8253g / (m 2 · 24h); it can resist 500mm hydrostatic pressure for 3min, which meets the requirement of water resistance of medical dressing; the hemostasis performance test result is an average flow rate reduction of 0.006μg / s 2 ; the tensile strength of the hemostatic, breathable and bacteria-proof nanofiber membrane is 9.7MPa.

[0124] Example 4

[0125] The preparation method of the hemostatic, breathable and bacteria-proof nanofiber membrane comprises the following steps:

[0126] Firstly, polyurethane is added in a mixed solvent with a mass ratio of dimethylformamide:tetrahydrofuran=3:1, and is dissolved by heating and stirring at 60℃ for 12h to prepare spinning solution A, wherein the concentration of polyurethane in the spinning solution A is 25wt%.

[0127] Then, sodium dodecyl benzene sulfonate is added in dimethylformamide, and polyhydroxybutyrate is added after uniform mixing, and is stirred and dissolved for 12h to prepare spinning solution B, wherein the concentration of sodium dodecyl benzene sulfonate in the spinning solution B is 2wt%, and the concentration of polyhydroxybutyrate is 8wt%.

[0128] Firstly, the spinning solution A is added to an electrostatic spinning device to perform electrostatic spinning, thereby preparing an outer layer nanofiber membrane; the spinning parameters of the outer layer nanofiber membrane are as follows: spinning temperature 10℃, humidity 10%, spinning voltage 20KV, spinning distance 20cm, and spinning rate 0.5ml / h.

[0129] Then the spinning solution B is added into the electrospinning equipment to continue spinning on the outer layer nanofiber membrane to prepare the inner layer nanofiber membrane, and the double layer nanofiber membrane, i.e. the composite fiber membrane. The spinning parameters of the inner layer nanofiber membrane are as follows: spinning temperature 50℃, humidity 90%, spinning voltage 17KV, spinning distance 16cm, and spinning rate 2ml / h.

[0130] In the composite fiber membrane prepared by the above method, the thickness of the outer layer nanofiber membrane is 10 microns, the average diameter of the nanofiber is 800nm, and the average pore size between the fibers is 800nm; the thickness of the inner layer nanofiber membrane is 100 microns, the average diameter of the fiber is 100nm, and the average pore size between the fibers is 100nm. The fibers are adhered to each other and to the outer layer fibers (as shown in Figure 1

[0131] The composite fiber membrane can 100% block bacteria penetration, meeting the requirements of medical dressings. Its water vapor transmission rate is 7570g / (m 2 ·24h); it can withstand 500mm hydrostatic pressure for 3min, meeting the water resistance requirements of medical dressings; and the tensile strength of the composite fiber membrane is 11MPa.

[0132] A mixed solvent of acetic acid:water=4:1 (volume ratio) is configured, 10% (volume percentage) dimethylformamide is added into the mixed solvent, chitosan is added and dissolved to prepare a hemostatic agent solution with a concentration of 6wt%; the hemostatic agent solution is sprayed on the inner layer nanofiber membrane of the above composite fiber membrane by electrostatic spraying to prepare a hemostatic and breathable bacteria-blocking nanofiber membrane; the electrostatic spraying voltage is 20KV, the solution extrusion rate is 1.5mL / h, the environmental temperature is 35℃, and the humidity is 40%.

[0133] The hemostatic and breathable bacteria-blocking nanofiber membrane prepared by the above method comprises a composite fiber membrane and a hemostatic agent; the content of the hemostatic agent is 1.5wt% based on the total weight of the hemostatic and breathable bacteria-blocking nanofiber membrane.

[0134] The hemostatic and breathable bacteria-blocking nanofiber membrane can also 100% block bacteria penetration, meeting the requirements of medical dressings. Its water vapor transmission rate is 7153g / (m 2 ·24h); it can withstand 500mm hydrostatic pressure for 3min, meeting the water resistance requirements of medical dressings; the hemostatic performance test result is an average flow rate reduction of 0.013μg / s 2 ; and the tensile strength of the hemostatic and breathable bacteria-blocking nanofiber membrane is 10.6MPa.

[0135] Example 5

[0136] The preparation method of the hemostatic and breathable bacteria-blocking nanofiber membrane comprises the following steps:

[0137] ​First, polyamide 6 was added to a mixed solvent with a mass ratio of formic acid to water = 9:1, and stirred to dissolve. The mixture was stirred for 12 hours until it was completely dissolved to prepare a spinning solution A. The concentration of polyamide 6 in the spinning solution A was 20 wt %.

[0138] Then, silk fibroin was added into water with a solution mass concentration of 10 wt%, and 0.005 wt% of dimethyloctadecyltrimethoxysilylpropylammonium chloride was added. The mixture was heated and stirred to dissolve for 12 h to prepare spinning solution B. In the spinning solution B, the concentration of silk fibroin was 10 wt%, and the concentration of dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride was 0.005 wt%.

[0139] First, the spinning solution A was added to the electrospinning equipment for electrospinning to prepare the outer nanofiber membrane; the spinning parameters of the outer nanofiber membrane were as follows: spinning temperature 150°C, humidity 25%, spinning voltage 20KV, spinning distance 20cm, and spinning rate 1.5ml / h.

[0140] Spinning solution B was then added to the electrospinning apparatus, and spinning continued on the outer nanofiber membrane to produce an inner nanofiber membrane. This double-layer nanofiber membrane is now a composite fiber membrane. The spinning parameters for the inner nanofiber membrane were: spinning temperature 40°C, humidity 50%, spinning voltage 16 kV, spinning distance 16 cm, and spinning rate 0.5 ml / h.

[0141] In the composite fiber membrane prepared by the above method, the outer layer nanofiber membrane is 70 microns thick, the average diameter of the nanofibers is 350nm, and the average pore size between the fibers is 400nm; the inner layer nanofiber membrane is 10 microns thick, the average fiber diameter is 50nm, and the average pore size between the fibers is 50nm. The fibers are adhered to each other and to the outer layer fibers.

[0142] The composite fiber membrane can 100% block bacteria penetration and meet the requirements of medical dressings. Its water vapor permeability is 6123g / (m 2 24h); can withstand 500mm hydrostatic pressure for 3min, meeting the water-blocking performance requirements of medical dressings; the tensile strength of the composite fiber membrane is 12MPa.

[0143] A mixed solvent of hexafluoroisopropanol: lactic acid = 1:1 (volume ratio) was prepared, 1% water by volume was added to the mixed solvent, chitosan was added and fully dissolved to prepare a hemostatic solution with a concentration of 10wt%; the hemostatic solution was sprayed on the inner nanofiber membrane of the above-mentioned composite fiber membrane by electrostatic spraying to prepare a hemostatic, breathable, and bacteria-isolating nanofiber membrane; the electrostatic spray voltage was 30kV, the solution extrusion rate was 2mL / h, the ambient temperature was 40°C, and the humidity was 10%.

[0144] The hemostatic and bacteria-proof nanofiber membrane prepared by the above method comprises a composite fiber membrane and a hemostatic agent; the content of the hemostatic agent is 2wt% based on the total weight of the hemostatic and bacteria-proof nanofiber membrane.

[0145] The hemostatic and bacteria-proof nanofiber membrane can also 100% block the penetration of bacteria, meeting the requirements of medical dressings. The water vapor transmission rate thereof is 5642g / (m 2 ·24h); it can withstand 500mm of hydrostatic pressure for 3min, meeting the water resistance requirements of medical dressings; the hemostasis performance test result is an average flow rate reduction of 0.016μg / s 2 ; the tensile strength of the nanofiber membrane is 12MPa.

[0146] Example 6

[0147] The preparation method of the hemostatic and bacteria-proof nanofiber membrane of Example 2 is the same, and the only difference is that:

[0148] The mixed solvent used in the hemostatic agent solution is acetic acid and chloroform, and the volume percentage content of chloroform in the above mixed solvent is 5%, and the concentration of the hemostatic agent solution is 5wt%.

[0149] The hemostatic and bacteria-proof nanofiber membrane prepared by the above method comprises a composite fiber membrane and a hemostatic agent; the content of the hemostatic agent is 0.65wt% based on the total weight of the hemostatic and bacteria-proof nanofiber membrane.

[0150] The hemostatic and bacteria-proof nanofiber membrane can also 100% block the penetration of bacteria, meeting the requirements of medical dressings. The water vapor transmission rate thereof is 6912g / (m 2 ·24h); it can withstand 500mm of hydrostatic pressure for 3min, meeting the water resistance requirements of medical dressings; the hemostasis performance test result is an average flow rate reduction of 0.012μg / s 2 ; the tensile strength of the nanofiber membrane is 12.7MPa.

[0151] Example 7

[0152] The preparation method of the hemostatic and bacteria-proof nanofiber membrane of Example 2 is the same, and the only difference is that:

[0153] The mixed solvent used in the hemostatic agent solution is acetic acid and tetrahydrofuran, and the volume percentage content of tetrahydrofuran in the above mixed solvent is 8%, and the concentration of the hemostatic agent solution is 6wt%.

[0154] The hemostatic and bacteria-proof nanofiber membrane prepared by the above method comprises a composite fiber membrane and a hemostatic agent; the content of the hemostatic agent is 0.8wt% based on the total weight of the hemostatic and bacteria-proof nanofiber membrane.

[0155] The hemostatic breathable bacteria-isolating nanofiber membrane can also 100% block bacteria penetration, meeting the requirements of medical dressings. The water vapor transmission rate thereof is 6878 g / (m 2 ·24h); it can withstand 500mm of hydrostatic pressure for 3min, meeting the water resistance requirements of medical dressings; the hemostatic performance test result is an average flow rate reduction of 0.013μg / s 2 ; and the tensile strength of the composite fiber membrane is 12.3MPa.

[0156] The hemostatic breathable bacteria-isolating dressings prepared in the embodiments of the present application can effectively stop bleeding, have good biocompatibility and no irritation to tissues; do not adhere to wounds, and the fibers adhere to each other, so that they will not be left on the surface of the wound during dressing change, causing inflammation; have elasticity and good compliance, and can be used for sports sites; at the same time, the breathable bacteria-isolating dressings also have a waterproof function, making the life of patients more convenient.

[0157] Comparative Example 1

[0158] The preparation method thereof is the same as that of Example 1, and the only difference is that only the outer layer nanofiber membrane of the composite fiber membrane of Example 1 is prepared.

[0159] The bacteria-isolating experiment result shows that the outer layer nanofiber membrane cannot block bacteria and cannot meet the waterproof performance requirements, and the tensile strength thereof is 5MPa, and the water vapor transmission rate thereof is 8156g / (m 2 ·24h).

[0160] The nanofiber membrane prepared by electrospinning is formed by random accumulation of nanofibers, and the pores formed by the interweaving of the fibers are of uneven sizes. Although the average pore size of the nanofiber membrane of Comparative Example 1 is 550nm, it cannot be guaranteed that all the pore sizes are less than 550nm, and local defects may exist in the nanofiber membrane during industrial production. Therefore, for bacteria with sizes of about 0.5-6 microns, the bacteria can penetrate through the outer layer nanofiber membrane, and the fiber membrane cannot 100% block bacteria, failing to meet the bacteria-isolating performance requirements of medical dressings (the national standard for the bacteria-isolating performance of medical dressings requires that the dressing 100% block bacteria).

[0161] Comparative Example 2

[0162] The preparation method thereof is the same as that of Example 1, and the only difference is that only the composite fiber membrane is prepared, and the spinning parameters of the outer layer nanofiber membrane thereof are: spinning temperature 20℃, humidity 20%, and the spinning parameters of the inner layer nanofiber membrane are: spinning temperature 20℃, humidity 20%.

[0163] The composite fiber membrane prepared by the above method has an outer layer nanofiber membrane with a thickness of 100 microns, an average nanofiber diameter of 500 nm, and an average pore size between fibers of 550 nm, and an inner layer nanofiber membrane with a thickness of 100 microns, an average fiber diameter of 300 nm, and an average pore size between fibers of 1100 nm, and a large number of pores caused by liquid droplets on the fiber membrane (as shown in Figure 2

[0164] The bacteria isolation experiment result shows that bacteria cannot be blocked, and the tensile strength is 4 MPa, which cannot meet the waterproof performance requirement.

[0165] Comparative Example 3

[0166] The preparation method is the same as that of Example 1, and the only difference is that only the composite fiber membrane is prepared, and sodium chloride is not added in the preparation process of the inner layer nanofiber membrane.

[0167] The composite fiber membrane prepared by the above method has an outer layer nanofiber membrane with a thickness of 100 microns, an average nanofiber diameter of 500 nm, and an average pore size between fibers of 550 nm, and an inner layer nanofiber membrane with a thickness of 100 microns, an average fiber diameter of 430 nm, and an average pore size between fibers of 500 nm.

[0168] The bacteria isolation experiment result shows that bacteria cannot be blocked, and the tensile strength is 7 MPa, and the water vapor transmission rate is 4900 g / (m 2 ·24h), which can meet the waterproof requirement. Although the pore size of the inner layer nanofiber membrane of Comparative Example 3 is large and the pore size of the outer layer nanofiber membrane is small, the difference between the pore sizes of the two membranes is small, the gradient pore size has a weak drainage effect, and the water vapor transmission rate is small.

[0169] Comparative Example 4

[0170] The preparation method is the same as that of Example 1, and the only difference is that only the inner layer nanofiber membrane of Example 1 is prepared.

[0171] The nanofiber membrane prepared by the above method is broken under a static water pressure of 500 mm, which cannot meet the waterproof performance requirement, and the tensile strength is 2.1 MPa, and the water vapor transmission rate is 5310 g / (m 2 ·24h).

[0172] The hemostatic, breathable, and bacteria-isolating dressing of the application has a conventional dressing structure in the prior art, which comprises a hemostatic, breathable, and bacteria-isolating nanofiber membrane 3, an adhesive layer 2, and a release paper 1.

[0173] The specific structure of the hemostatic, breathable, and bacteria-isolating dressing of the application includes but is not limited to a structure similar to Figure 5 ​The edge of the hemostatic and antibacterial nanofiber membrane 3 is attached with a double-sided non-woven tape (i.e., the adhesive layer 2), and a release paper 1 is attached to the adhesive layer 2, thereby obtaining the hemostatic and antibacterial dressing. When the hemostatic and antibacterial dressing of the present application is used, the chitosan (hemostatic agent) in the hemostatic and antibacterial nanofiber membrane 3 faces the wound (i.e., is attached to the wound).

Claims

1. A method for preparing a hemostatic, breathable, and bacteria-isolating nanofiber membrane, characterized in that The method comprises the following steps: (1) Preparation of spinning solution A: Add a hydrophobic polymer to solvent A and fully dissolve it to prepare spinning solution A; (2) Preparation of spinning solution B: Adding a conductivity regulator and a hydrophobic polymer to solvent B and fully dissolving them to obtain spinning solution B; (3) Preparation of outer nanofiber membrane: electrospinning the spinning solution A to obtain an outer nanofiber membrane; (4) Preparation of a composite fiber membrane: Fibers obtained by electrospinning the spinning solution B are received on the outer nanofiber membrane to form an inner nanofiber membrane; the outer nanofiber membrane and the inner nanofiber membrane form a composite fiber membrane; wherein the outer nanofiber membrane has a large pore size and the inner nanofiber membrane has a small pore size; (5) Preparation of hemostatic solution: Add the hemostatic agent to solvent C and fully dissolve it to prepare a hemostatic solution; (6) Preparation of hemostatic, breathable, and bacteria-isolating nanofiber membrane: loading the hemostatic solution onto the inner nanofiber membrane of the composite fiber membrane to prepare the hemostatic, breathable, and bacteria-isolating nanofiber membrane; The solvent A is a mixed solvent selected from a mixed solvent formed by an organic solvent with a boiling point greater than 100°C and a solvent with a boiling point of 100°C or below; The solvent B is selected from one or a combination of organic solvents having a boiling point greater than 100°C; The solvent C is selected from one or a combination of formic acid, acetic acid, trifluoroacetic acid, lactic acid, hydrochloric acid, hexafluoroisopropanol or water; and the hemostatic agent is selected from chitosan.

2. The method for preparing the hemostatic, breathable, bacteria-isolating nanofiber membrane according to claim 1, characterized in that: In the solvent A or solvent B, the organic solvent having a boiling point greater than 100° C. is the same or different and is independently selected from one or a combination of dimethylformamide, dimethylacetamide, dimethyl sulfoxide, dioxane, octane, toluene, formic acid, acetic acid, formamide, acetamide, butyl acetate, ethylene glycol, propylene glycol, butanol, cyclohexanone, cyclopentanone or N-methylpyrrolidone; In the solvent A, the solvent having a boiling point of 100° C. or below is selected from one or a combination of tetrahydrofuran, acetone, chloroform, dichloromethane, trichloroethane, acetonitrile, n-hexane, cyclohexane, ether, methanol, ethanol, propanol, trifluoroethanol, hexafluoroisopropanol, ethyl acetate, trifluoroacetic acid, methyl ethyl ketone or water; and / or, In the solvent A, the mass ratio of the organic solvent with a boiling point greater than 100° C. to the solvent with a boiling point of 100° C. or less is 0.5-9:

1.

3. The method for preparing the hemostatic, breathable, bacteria-isolating nanofiber membrane according to claim 1, characterized in that: The hydrophobic polymers in the spinning solution A and the spinning solution B are the same or different, and are independently selected from one or a combination of polyurethane, polycaprolactone, silk fibroin, polyvinyl chloride, polystyrene, polyamide, polyhydroxybutyrate, polybutylene succinate, polybutylene adipate / terephthalate, polyethylene terephthalate or polycarbonate; and / or, The solvent C also includes solvent D; The solvent D is selected from one or a combination of dimethylformamide, dimethylacetamide, dimethyl sulfoxide, dioxane, toluene, formamide, acetamide, butyl acetate, cyclohexanone, cyclopentanone, tetrahydrofuran, acetone, chloroform, dichloromethane, trichloroethane, acetonitrile, trifluoroethanol, ethyl acetate, methyl ethyl ketone or N-methylpyrrolidone; The volume percentage of the solvent D in the solvent C is 1% to 10%.

4. The method for preparing the hemostatic, breathable, bacteria-isolating nanofiber membrane according to claim 1, characterized in that: In the spinning solution A, The concentration of the hydrophobic polymer is 12 wt% to 30 wt%; and / or, In the spinning solution B, The concentration of the hydrophobic polymer is 4 wt% to 12 wt%; and / or, The concentration of the conductivity regulator is 0.001wt%~3wt%; and / or, In the hemostatic solution, The concentration of the hemostatic agent is 1wt%~10wt%.

5. The method for preparing the hemostatic, breathable, bacteria-isolating nanofiber membrane according to claim 4, characterized in that: In the spinning solution A, The concentration of the hydrophobic polymer is 14 wt% to 25 wt%; and / or, In the spinning solution B, The concentration of the hydrophobic polymer is 6 wt% to 10 wt%; and / or, The concentration of the conductivity regulator is 0.01 wt%~1 wt%.

6. The method for preparing the hemostatic, breathable, bacteria-isolating nanofiber membrane according to claim 1, characterized in that: The conductivity regulator is selected from one or a combination of inorganic salts, ionic surfactants, quaternary ammonium salts, water, hydrochloric acid or acetic acid.

7. The method for preparing the hemostatic, breathable, bacteria-isolating nanofiber membrane according to claim 6, characterized in that: The inorganic salt is selected from one or a combination of sodium chloride and lithium chloride; and / or, The ionic surfactant is selected from one or a combination of sodium dodecylbenzenesulfonate or sodium dodecylsulfonate; and / or, The quaternary ammonium salt is selected from one or a combination of dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride, alkyldimethylbenzylammonium chloride or octyldecyldimethylammonium chloride.

8. The method for preparing the hemostatic, breathable, bacteria-isolating nanofiber membrane according to claim 1, characterized in that: In step (3), the spinning temperature of the electrospinning is above 10° C. and the spinning humidity is above 10%; and / or, In step (4), the spinning temperature of the electrospinning is above 30° C. and the spinning humidity is above 40%; and / or, In step (6), the loading method is spraying.

9. The method for preparing the hemostatic, breathable, bacteria-isolating nanofiber membrane according to claim 8, characterized in that: In step (3), the spinning temperature of the electrospinning is 10-30° C., and the spinning humidity is 10%-50%; In step (4), the spinning temperature of the electrospinning is 30-50° C., and the spinning humidity is 40%-90%; In step (6), the loading method is electrostatic spraying.

10. The method for preparing the hemostatic, breathable, bacteria-isolating nanofiber membrane according to claim 9, characterized in that: When spraying by electrostatic spraying, the voltage of the electrostatic spray is 10~30KV, the solution extrusion rate is 0.5~2mL / h, the ambient temperature is 20~40℃, and the humidity is 10%~40%.

11. The hemostatic, breathable, and bacteria-isolating nanofiber membrane prepared according to the method of any one of claims 1 to 10, characterized in that: The hemostatic, breathable, and bacteria-isolating nanofiber membrane comprises a composite fiber membrane and a hemostatic agent; Based on the total weight of the hemostatic, breathable, and bacteria-isolating nanofiber membrane as 100%, the content of the hemostatic agent is 0.1 wt%-2 wt%; In the composite fiber membrane, the average pore size between fibers in the outer nanofiber membrane is larger than the average pore size between fibers in the inner nanofiber membrane.

12. The hemostatic, breathable, bacteria-isolating nanofiber membrane according to claim 11, characterized in that: In the composite fiber membrane, The outer nanofiber membrane has an average fiber diameter of 350-800 nm; an average pore size between fibers of 400-800 nm; and a thickness of 10-200 microns. The average fiber diameter of the inner nanofiber membrane is 50nm~300nm; the average pore size between the fibers is 50~300nm; and the thickness is 10~200 microns; The overlapping points of the fibers in the inner nanofiber membrane are adhered to each other.

13. The hemostatic, breathable, bacteria-isolating nanofiber membrane according to claim 12, characterized in that: In the composite fiber membrane, The average fiber diameter of the outer nanofiber membrane is 500-800 nm; the average pore size between the fibers is 500-800 nm; The average fiber diameter of the inner nanofiber membrane is 50nm-100nm; the average pore size between the fibers is 50-200nm.

14. A hemostatic, breathable, and bacteria-isolating dressing prepared using the hemostatic, breathable, and bacteria-isolating nanofiber membrane according to any one of claims 11 to 13.

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