An antibacterial, hemostatic, self-powered asymmetric hybrid fiber membrane and a preparation method thereof

Abstract

The application discloses an antibacterial, hemostatic and self-powered asymmetric hybrid fiber membrane and a preparation method thereof. The antibacterial, hemostatic and self-powered asymmetric hybrid fiber membrane is composed of three layers of fiber membranes, and comprises a bottom piezoelectric fiber membrane, a core conductive fiber membrane and a surface fiber membrane; the fiber membranes are connected through spinning; the water contact angle of the bottom piezoelectric fiber membrane is 140-150 degrees; the water contact angle of the core conductive fiber membrane is 50-60 degrees; and the water contact angle of the surface fiber membrane is 20-30 degrees. The application further discloses a preparation method thereof. The hybrid nanofiber membrane has the advantages of simple and controllable preparation method, good material cell and blood compatibility, cell migration and blood coagulation promotion functions, wound specific bacteria growth inhibition, self-powered stimulation for accelerating cell proliferation, and good application prospect in the fields of wound dressings and bionic skins.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of biomedical materials, and particularly relates to an antibacterial, hemostatic, self-powered asymmetric hybrid fiber membrane and a preparation method thereof. BACKGROUND

[0002] Skin is the largest organ of the human body, and plays a crucial role in maintaining homeostasis and resisting external stimuli such as bacteria and viruses. Wound dressings, as a protective barrier against external bacterial invasion, help wound healing. The most commonly used wound dressings in clinical practice are cotton pads, gauze / bandages and hydrogels. However, these traditional passive dressings are insufficient in providing a sterile environment and maintaining appropriate wound moisture levels, and are difficult to remove due to adhesion, which can cause further damage. Therefore, the development of new wound dressings has become a research hotspot in recent years.

[0003] Fibers are a kind of bandaging material that has attracted much attention in recent years, mainly due to their unique structure, adjustable physical and mechanical properties. Nanofibers have a structure similar to the natural extracellular matrix (ECM), with a large surface area and high porosity, which is beneficial to the circulation of essential nutrients and metabolites required for cell growth. Studies have shown that endogenous electric fields, as physical signals in living organisms, can stimulate cell growth and promote wound healing (Wang J, Lin J W, Chen L, et al. Endogenous Electric-Field-Coupled Electrospun Short Fiber via Collecting Wound Exudation [J]. Adv. Mater. 2022, 34, 2108325).

[0004] Chinese patent document CN 115387029 A discloses a preparation method of a striped structure self-powered wound plaster, which obtains a striped structure self-powered fiber membrane by directional electrospinning, can convert the mechanical force received by the skin into an electric stimulus and conduct it to the wound surface, and promote the growth and migration of cells.

[0005] However, single hemostatic, electric stimulation and other properties cannot meet the complex requirements of the damage site in terms of functional and biological environment of the dressing in practical application. Therefore, in recent years, people expect to enrich the performance of fiber dressings through the superposition of "layers" and synergistic effect.

[0006] Chinese patent document CN 109700562 A discloses a multi-layer double-oriented scaffold simulating the structure and function of natural blood vessels and a preparation method thereof, which obtains a bionic blood vessel that is easy to uniformly seed cells by adjusting the orientation and folding and curling of the multi-layer fibers, and is suitable for deeper and more complex wound repair.

[0007] The material disclosed in Chinese patent document CN 115998937 A is composed of super-hydrophilic and super-hydrophobic fiber layers, and has a Janus two-sided structure with both wettability gradient and structural gradient, which enables it to have hemostatic, antibacterial and directional drug transport effects.

[0008] Taking into account the characteristics of the above materials, combining electrical stimulation with a multilayer structure better matches the structural characteristics of human skin. Therefore, a multilayer asymmetric dressing was designed. Functional components were screened and matched, and an asymmetric hybrid nanofiber membrane similar to human skin was prepared through electrospinning technology. Its antibacterial, hemostatic, and self-powered cell growth stimulation properties are of great research value in the field of wound dressing. Summary of the Invention

[0009] The first technical problem to be solved by the present invention is to provide an antibacterial, hemostatic, and self-powered asymmetric hybrid fiber membrane. The present invention uses electrospinning to prepare a three-layer asymmetric hybrid fiber membrane material through component screening and process exploration. The bottom fiber membrane is hydrophobic and acts as a wound barrier to prevent environmental pollution and reduce bacterial adhesion. It can also generate electrical signals with changes in pressure to stimulate cell growth; the core fiber membrane is hydrophilic and acts as a conductive pathway while also slowly releasing antibacterial substances; the last surface fiber membrane is water-soluble and can quickly dissolve when it encounters wound tissue fluid, releasing chitosan for hemostasis and antibacterial effects.

[0010] The second technical problem addressed by this invention is to provide a method for preparing an asymmetric hybrid fiber membrane with antibacterial, hemostatic, and self-powered properties. The material prepared by this method exhibits significantly higher cell migration rates, antibacterial rates, and coagulation effects than the control group, and is expected to be used in wound dressings.

[0011] To solve the first technical problem, the present application adopts the technical solutions as follows :

[0012] An antibacterial, hemostatic, and self-powered asymmetric hybrid fiber membrane consists of three fiber membrane layers, including:

[0013] - bottom piezoelectric fiber membrane;

[0014] - Conductive fiber membrane in the core layer;

[0015] -Surface fiber membrane;

[0016] Each layer of fiber membrane is connected by spinning;

[0017] The water contact angle of the bottom piezoelectric fiber membrane is 140-150 degrees;

[0018] The water contact angle of the core layer conductive fiber membrane is 50-60 degrees;

[0019] The water contact angle of the surface fiber membrane is 20-30 degrees.

[0020] Preferably, the bottom piezoelectric fiber membrane is prepared by dissolving a piezoelectric polymer and then using an electrostatic spinning technique.

[0021] More preferably, the piezoelectric polymer is selected from one or more of polyvinylidene fluoride, polymethyl methacrylate, and epoxy resin.

[0022] Preferably, the core layer conductive fiber membrane is prepared by electrospinning technology using a spinning solution of the core layer formed by mixing a hydrophobic polymer, gelatin and an inorganic conductive nanomaterial.

[0023] More preferably, the hydrophobic polymer is selected from one or more of polycaprolactone, polyurethane, and polylactic acid-glycolic acid copolymer; and the inorganic conductive nanomaterial is selected from one or more of copper nanoparticles, carbon nanotubes, silver nanowires, and gold nanoparticles.

[0024] Preferably, the surface fiber membrane is prepared by electrospinning a core layer spinning solution formed by mixing a water-soluble polymer and chitosan.

[0025] More preferably, the water-soluble polymer is selected from one or more of polyvinyl alcohol, polyethylene oxide, and polyvinyl pyrrolidone.

[0026] To solve the second technical problem, the present application adopts the technical solutions as follows :

[0027] A method for preparing an antibacterial, hemostatic, and self-powered asymmetric hybrid fiber membrane comprises the following steps:

[0028] 1) dissolving a piezoelectric polymer in an organic solvent to obtain a spinning solution, and then using the spinning solution to prepare a bottom piezoelectric fiber membrane through an electrospinning technique;

[0029] 2) dissolving a hydrophobic polymer and gelatin in an acetic acid solution and stirring the mixture uniformly, and doping the mixture with an inorganic conductive nanomaterial to obtain a spinning solution for a core layer, and electrospinning the solution on the basis of the underlying fiber membrane to obtain a core layer conductive fiber membrane;

[0030] 3) Dissolving a water-soluble polymer and chitosan in an acetic acid solution to obtain a surface spinning solution, electrospinning the surface fiber membrane on the basis of the bottom layer and core layer conductive fiber membranes, and finally preparing an antibacterial, hemostatic, and self-powered asymmetric hybrid fiber membrane.

[0031] As a further improvement of the technical solution, in step 1), the piezoelectric polymer is selected from one or more of polyvinylidene fluoride, polymethyl methacrylate, and epoxy resin; and the organic solvent is selected from one or more of N,N-dimethylformamide, acetone, dimethyl sulfoxide, and acetic acid.

[0032] Preferably, in step 1), the mass concentration of the piezoelectric polymer is 5-20%, and the dissolving temperature is 30-50℃.

[0033] Preferably, in step 1), the process parameters of electrospinning are as follows: voltage 15-25kV, receiving distance 16-23cm, and feeding rate of spinning solution 0.001-0.02mL / min; and the environmental conditions of spinning are as follows: temperature 32±6℃, and humidity 40±10%.

[0034] As a further improvement of the technical solution, in step 2), the hydrophobic polymer is selected from one or more of polycaprolactone, polyurethane, and polylactic acid-glycolic acid copolymer.

[0035] Preferably, in step 2), the inorganic conductive nanomaterial is selected from one or more of copper nanoparticles, carbon nanotubes, silver nanowires, and gold nanoparticles.

[0036] Preferably, in step 2), the total mass fraction of the hydrophobic polymer and gelatin is 10-30%, the mass ratio of the hydrophobic polymer to gelatin is 4:1-1:4, the mass concentration of acetic acid solution is 75-85%, and the solute proportion of the inorganic conductive nanomaterial is 1-10%.

[0037] Preferably, in step 2), the process parameters of spinning on the basis of the bottom fiber membrane are as follows: voltage 12-22kV, receiving distance 18-22cm, and feeding rate of spinning solution 0.001-0.01mL / min; and the environmental conditions of spinning are as follows: temperature 32±6℃, and humidity 48±5%.

[0038] As a further improvement of the technical solution, in step 3), the water-soluble polymer is selected from one or more of polyvinyl alcohol, polyethylene oxide, and polyvinylpyrrolidone.

[0039] Preferably, in step 3), the total mass fraction of the water-soluble polymer and chitosan is 1-4%, the mass ratio of the water-soluble polymer to chitosan is 1:9-1:1, and the mass concentration of acetic acid solution is 45-55%.

[0040] Preferably, in step 3), the process parameters of spinning on the basis of the bottom fiber membrane and the core layer fiber membrane are as follows: voltage 12-22kV, receiving distance 18-22cm, and feeding rate of spinning solution 0.001-0.01mL / min; and the environmental conditions of spinning are as follows: temperature 30±6℃, and humidity 45±5%.

[0041] Any range recited in the present application includes the end values and any intervening value and any sub-range encompassed therein.

[0042] Unless otherwise specified, all raw materials in the present invention can be purchased commercially, and the equipment used in the present invention can adopt conventional equipment in the relevant field or refer to the existing technology in the relevant field.

[0043] Compared with the prior art, the present invention has the following beneficial effects:

[0044] 1. The present invention is designed with a three-layer asymmetric structure: the hydrophobic layer acts as a protective barrier for the wound surface, and after self-generating electricity, it is transmitted to cells through the conductive layer to stimulate growth; the water-soluble layer quickly dissolves when it encounters a moist wound, releasing chitosan to stop bleeding and fight bacteria.

[0045] 2. Natural organic matter and metal inorganic matter act synergistically as functional substances, not only having good antibacterial and hemostatic effects, but also reducing cell resistance;

[0046] 3. The electrospinning process is simple and controllable, and the prepared fiber material is structurally similar to the extracellular matrix, which helps cell migration and growth. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0048] Figure 1 This is a scanning electron microscope image of the product of Example 1 of the present invention; wherein a is the planar structure of the surface layer, b is the planar structure of the core layer, and c is the planar structure of the bottom layer;

[0049] Figure 2 This is a transmission electron microscope image of the core fiber of the product of Example 1 of the present invention;

[0050] Figure 3 This is a cross-sectional scanning electron microscope image of the product of Example 1 of the present invention;

[0051] Figure 4 The water contact angle photos of the product of Example 1 of the present invention are as follows: a is a photo of the water contact angle of the surface layer, b is a photo of the water contact angle of the core layer, and c is a photo of the water contact angle of the bottom layer;

[0052] Figure 5 This is a histogram of the antibacterial experiment of the product of Example 1 of the present invention;

[0053] Figure 6 a Histogram of the cell compatibility of the product of Example 1 of the present invention; Figure 6 b is a histogram of cell scratches in Example 1 of the present invention;

[0054] Figure 7 This is a histogram of the coagulation performance of the product of Example 1 of the present invention;

[0055] Figure 8 This is an open circuit voltage test diagram of the product of Example 1 of the present invention;

[0056] Figure 9 A scanning electron microscope image of the core layer of the product of Example 2 of the present application;

[0057] Figure 10 A cross-sectional scanning electron microscope image of the product of Example 2 of the present application;

[0058] Figure 11 A cross-sectional scanning electron microscope image of the product of Comparative Example 1 of the present application;

[0059] Figure 12 A scanning electron microscope image of the surface layer of the product of Comparative Example 2 of the present application. DETAILED DESCRIPTION

[0060] In order to more clearly illustrate the present application, the present application will be further described below in conjunction with examples. It should be understood by those skilled in the art that the specific descriptions below are illustrative and not limiting, and should not limit the scope of protection of the present application.

[0061] Reference is made to Figure 3 As shown, as one aspect of the present application, the present application is an antibacterial, hemostatic, self-powered asymmetric hybrid fiber membrane composed of three layers of fiber membranes, including:

[0062] -a bottom layer of piezoelectric fiber membrane 1, which functions to convert different forces into electrical signals through piezoelectric effect;

[0063] -a core layer of conductive fiber membrane 2, which functions to conduct the electrical signals generated by the piezoelectric fiber membrane to the surface layer and even to the skin through the conductive path composed of nano silver wires, and continuously antibacterial under the effect of sustained release;

[0064] -a surface layer of fiber membrane 3, which functions to quickly kill bacteria and stop bleeding;

[0065] The fiber membranes between each layer are connected by spinning;

[0066] The water contact angle of the bottom layer of piezoelectric fiber membrane is 140-150 degrees;

[0067] The water contact angle of the core layer of conductive fiber membrane is 50-60 degrees;

[0068] The water contact angle of the surface layer of fiber membrane is 20-30 degrees.

[0069] In some embodiments of the present application, the bottom layer of piezoelectric fiber membrane is prepared by dissolving a piezoelectric polymer and then using electrospinning technology.

[0070] In some embodiments of the present application, the piezoelectric polymer is selected from one or more of polyvinylidene fluoride, polymethyl methacrylate, and epoxy resin.

[0071] In some embodiments of the present application, the core layer conductive fiber membrane is formed by mixing a hydrophobic polymer, gelatin and inorganic conductive nanomaterials to form a spinning solution of the core layer, and then prepared by electrospinning technology.

[0072] In some embodiments of the present application, the hydrophobic polymer is selected from one or more of polycaprolactone, polyurethane, polylactic acid-glycolic acid copolymer; and the inorganic conductive nanomaterial is selected from one or more of copper nanoparticles, carbon nanotubes, silver nanowires, gold nanoparticles.

[0073] In some embodiments of the present application, the surface layer fiber membrane is formed by mixing a water-soluble polymer and chitosan to form a spinning solution of the core layer, and then prepared by electrospinning technology.

[0074] In some embodiments of the present application, the water-soluble polymer is selected from one or more of polyvinyl alcohol, polyethylene oxide, polyvinylpyrrolidone.

[0075] As an aspect of the present application, the present application relates to an antibacterial, hemostatic and self-powered asymmetric hybrid fiber membrane and a preparation method thereof, comprising the following steps:

[0076] 1) dissolving a piezoelectric polymer in an organic solvent to obtain a spinning solution, and then preparing a bottom layer piezoelectric fiber membrane by electrospinning technology;

[0077] 2) dissolving a hydrophobic polymer and gelatin in acetic acid solution and stirring uniformly, and doping inorganic conductive nanomaterials to obtain a spinning solution of the core layer, and then electrospinning on the basis of the bottom layer fiber membrane to obtain a core layer conductive fiber membrane;

[0078] 3) dissolving a water-soluble polymer and chitosan in acetic acid solution to obtain a surface layer spinning solution, and then electrospinning on the basis of the bottom layer and core layer conductive fiber membrane to obtain a surface layer fiber membrane, and finally preparing an antibacterial, hemostatic and self-powered asymmetric hybrid fiber membrane.

[0079] In some embodiments of the present application, in step 1), the piezoelectric polymer is selected from one or more of polyvinylidene fluoride, polymethyl methacrylate, epoxy resin; and the organic solvent is selected from one or more of N,N-dimethylformamide, acetone, dimethyl sulfoxide, acetic acid.

[0080] In some embodiments of the present application, in step 1), the mass concentration of the piezoelectric polymer is 5-20%, and the dissolving temperature is 30-50℃.

[0081] In some embodiments of the present application, in step 1), the process parameters of electrospinning are: voltage 15-25kV, receiving distance 16-23cm, spinning solution feeding rate 0.001-0.02mL / min; and the spinning environmental conditions are: temperature 32±6℃, humidity 40±10%.

[0082] In some embodiments of the present application, in step 2), the hydrophobic polymer is selected from one or more of polycaprolactone, polyurethane, polylactic acid-glycolic acid copolymer.

[0083] In some embodiments of the present application, in step 2), the inorganic conductive nanomaterial is selected from one or more of copper nanoparticles, carbon nanotubes, silver nanowires, gold nanoparticles.

[0084] In some embodiments of the present application, in step 2), the total mass fraction of the hydrophobic polymer and gelatin is 10-30%, the mass ratio of the hydrophobic polymer and gelatin is 4:1-1:4, the mass concentration of the acetic acid solution is 75-85%; the solute of the inorganic conductive nanomaterial accounts for 1-10%.

[0085] In some embodiments of the present application, in step 2), the process parameters for spinning on the basis of the bottom layer fiber film are: voltage 12-22kV, receiving distance 18-22cm, spinning solution feeding rate 0.001-0.01mL / min; the spinning environmental conditions are temperature 32±6℃, humidity 48±5%.

[0086] In some embodiments of the present application, in step 3), the water-soluble polymer is selected from one or more of polyvinyl alcohol, polyethylene oxide, polyvinylpyrrolidone.

[0087] In some embodiments of the present application, in step 3), the total mass fraction of the water-soluble polymer and chitosan is 1-4%, the mass ratio of the water-soluble polymer and chitosan is 1:9-1:1, the mass concentration of the acetic acid solution is 45-55%.

[0088] In some embodiments of the present application, in step 3), the process parameters for spinning on the basis of the bottom layer and core layer fiber films are: voltage 12-22kV, receiving distance 18-22cm, spinning solution feeding rate 0.001-0.01mL / min; the spinning environmental conditions are temperature 30±6℃, humidity 45±5%.

[0089] Example 1

[0090] An antibacterial, hemostatic, self-powered asymmetric hybrid fiber film and a preparation method thereof, comprising the following steps:

[0091] 1) 0.89g of polyvinylidene fluoride (M w 400000) is weighed and added into 8g of N,N-dimethylformamide, stirred and dissolved at 40℃ for 4 hours to prepare a 10% mass fraction PVDF solution;

[0092] 2) Spinning conditions: Process parameters: voltage 20 kV, receiving distance 21 cm, feeding rate 0.01 mL / min; environmental conditions: temperature 32°C, humidity 45%, and the bottom piezoelectric nanofiber film is obtained after 6.5 h of spinning.

[0093] 3) 1.6 g of polycaprolactone and 0.4 g of gelatin are weighed and placed in 4.8 g of glacial acetic acid, and then 1.2 g of a silver nanowire water dispersion solution with a concentration of 31.5 mg / mL is added dropwise to obtain a mixed solution with a total mass fraction of polycaprolactone and gelatin of 25% and a mass ratio of 4:1. After stirring overnight, the spinning solution of the core layer fiber film is obtained by ultrasonic treatment for 15 min.

[0094] 4) Spinning conditions: Process parameters: voltage 18 kV, receiving distance 21 cm, feeding rate 0.008 mL / min; environmental conditions: temperature 30°C, humidity 45%, and the core layer conductive fiber film is obtained after 8 h of spinning with the bottom piezoelectric fiber film as the receiver.

[0095] 6) 37.11 mg of polyethylene oxide and 148.45 mg of chitosan are weighed and placed in 6 g of an acetic acid solution with a mass fraction of 50%, and then stirred overnight to obtain a surface spinning solution with a total mass fraction of polyethylene oxide and chitosan of 3% and a mass ratio of 1:4.

[0096] 7) Spinning conditions: Process parameters: voltage 18 kV, receiving distance 21 cm, feeding rate 0.008 mL / min; environmental conditions: temperature 32°C, humidity 48%, and the surface polyethylene oxide / chitosan fiber film is obtained after 8 h of spinning based on the first two layers of fiber films, and the overall product is an asymmetric three-layer hybrid nanofiber film.

[0097] As shown in Figure 4 , the water contact angles of the fibers in each layer are different, and the hydrophilic and hydrophobic properties are different.

[0098] As shown in Figure 5 , the inhibition rates of broad-spectrum bacteria and wound-specific bacteria Pseudomonas aeruginosa both reach more than 99%;

[0099] As shown in Figure 6 , the cell survival rate is greater than 90%, and the cell compatibility is good; as shown in Figure 6 b, the asymmetric three-layer hybrid nanofiber film can promote the cell migration rate to a greater extent through the synergistic effect of the materials in each layer.

[0100] As shown in Figure 7 , the asymmetric three-layer hybrid fiber shows good blood clotting effect.

[0101] As shown in Figure 8As shown, the same pressure is repeatedly applied to the material, and the material generates a stable voltage signal that can stimulate cell growth.

[0102] Example 2

[0103] An antibacterial, hemostatic, and self-powered asymmetric hybrid fiber membrane and a preparation method thereof, comprising the following steps:

[0104] 1) 0.89 g of polyvinylidene fluoride (M w 400000) was added to 8 g of N,N-dimethylformamide and stirred and dissolved at 40°C for 4 hours to prepare a 10% PVDF solution by mass fraction;

[0105] 2) Spinning conditions: Process parameters: voltage 20 kV, receiving distance 21 cm, feed rate 0.01 mL / min; environmental conditions: temperature 32°C, humidity 45%, spinning for 6.5 h to obtain the bottom piezoelectric nanofiber film.

[0106] 3) 1.6 g of polycaprolactone and 0.4 g of gelatin were weighed and placed in 4.8 g of glacial acetic acid, and then 1.2 g of a nano-silver wire water dispersion solution with a concentration of 67.5 mg / mL was added dropwise to obtain a mixed solution with a total mass fraction of polycaprolactone and gelatin of 25% and a mass ratio of 4:1. After stirring overnight, the spinning solution for the core layer fiber membrane was obtained by ultrasonic treatment for 15 min.

[0107] 4) Spinning conditions: Process parameters: voltage 18 kV, receiving distance 21 cm, feed rate 0.008 mL / min; environmental conditions: temperature 30°C, humidity 45%, with the bottom piezoelectric fiber membrane as the receiver, spinning for 8 h to obtain the core layer conductive fiber film.

[0108] 6) 37.11 mg of polyethylene oxide and 148.45 mg of chitosan were weighed and placed in 6 g of an acetic acid solution with a mass fraction of 50%, and stirred overnight to obtain a surface spinning solution with a total mass fraction of polyethylene oxide and chitosan of 3% and a mass ratio of 1:4.

[0109] 7) Spinning conditions: Process parameters: voltage 18 kV, receiving distance 21 cm, feed rate 0.008 mL / min; spinning environmental conditions: temperature 32°C, humidity 48%, and the surface polyethylene oxide / chitosan fiber membrane was obtained by continuing to spin for 8 h based on the previous two layers of fiber membranes, and the overall product was an asymmetric three-layer hybrid nanofiber membrane.

[0110] Figure 9 The scanning electron microscope image of the conductive core layer is shown, and the Figure 1The b phase is obviously thinner than the fiber, and the reason is that: due to the increase of the content of silver nanowires, the conductivity of the fiber is enhanced, and under the same process conditions, the fiber is pulled thinner by stronger electric field force, and due to the inhomogeneity of the adhesive system caused by the nanomaterial, part of the spindle appears.

[0111] Comparative Example 1

[0112] Example 1 is repeated, and the only difference is that the mass ratio of polycaprolactone and gelatin in the core layer spinning solution is changed to 1:4. Step 3) is changed: polycaprolactone 0.4g, gelatin 1.6g, respectively, are weighed and placed in 4.8g ice acetic acid, and then 1.2g silver nanowire water dispersion solution with a concentration of 31.5mg / mL is added dropwise, finally a mixed solution with a total mass fraction of polycaprolactone and gelatin of 25% and a mass ratio of 4:1 is obtained, and other conditions and specific operation steps are exactly the same as in Example 1.

[0113] Figure 11 The scanning electron microscope photograph of the product obtained in this example is shown in the figure. It can be seen from the figure that due to the significant increase of hydrophilic gelatin, the cross section of the product is obviously sticky, and with the increase of the hydrophilicity of the core layer, the release rate in the humid environment increases, more silver nanowires are released, which may cause the circuit of the conductive layer to be broken, and the product cannot conduct the electric stimulus to the surface layer.

[0114] Comparative Example 2

[0115] Example 1 is repeated, and the only difference is that the mass ratio of polycaprolactone and gelatin in the core layer spinning solution is changed to 1:4. Step 3) is changed: polycaprolactone 0.4g, gelatin 1.6g, respectively, are weighed and placed in 4.8g ice acetic acid, and then 1.2g silver nanowire water dispersion solution with a concentration of 31.5mg / mL is added dropwise, finally a mixed solution with a total mass fraction of polycaprolactone and gelatin of 25% and a mass ratio of 4:1 is obtained, and other conditions and specific operation steps are exactly the same as in Example 1.

[0116] The results show that due to the repulsion of the high content of chitosan in the surface layer at the needle, liquid droplets appear at the needle during the spinning process, and the fiber structure cannot be formed.

[0117] Obviously, the above examples and comparative examples of the present application are only examples for clearly illustrating the present application, and are not a limitation on the embodiments of the present application. For ordinary skilled persons in the art, other different forms of changes or variations can be made on the basis of the above description. Here, all the embodiments cannot be exhausted. Any obvious changes or variations derived from the technical solutions of the present application still fall within the protection scope of the present application.

Claims

1. An antibacterial, hemostatic, and self-powered asymmetric hybrid fiber membrane, consisting of three fiber membrane layers, including: - bottom piezoelectric fiber membrane; - Conductive fiber membrane in the core layer; -Surface fiber membrane; Each layer of fiber membrane is connected by spinning; The water contact angle of the bottom piezoelectric fiber membrane is 140-150 degrees; The water contact angle of the core layer conductive fiber membrane is 50-60 degrees; The water contact angle of the surface fiber membrane is 20-30 degrees; The bottom piezoelectric fiber membrane is prepared by dissolving a piezoelectric polymer and then using an electrostatic spinning technique; The core conductive fiber membrane is prepared by electrospinning technology using a spinning solution of the core layer formed by mixing a hydrophobic polymer, gelatin and an inorganic conductive nanomaterial; The surface fiber membrane is made of a spinning solution of a core layer formed by mixing a water-soluble polymer and chitosan, and then is prepared by electrostatic spinning technology.

2. The antibacterial, hemostatic, self-powered asymmetric hybrid fiber membrane according to claim 1, characterized in that: The piezoelectric polymer is polyvinylidene fluoride.

3. The antibacterial, hemostatic, self-powered asymmetric hybrid fiber membrane according to claim 1, characterized in that: The hydrophobic polymer is selected from one or more of polycaprolactone, polyurethane, and polylactic acid-glycolic acid copolymer; the inorganic conductive nanomaterial is selected from one or more of copper nanoparticles, carbon nanotubes, silver nanowires, and gold nanoparticles.

4. The antibacterial, hemostatic, self-powered asymmetric hybrid fiber membrane according to claim 1, characterized in that: The water-soluble polymer is selected from one or more of polyvinyl alcohol, polyethylene oxide, and polyvinyl pyrrolidone.

5. The method for preparing an antibacterial, hemostatic, self-powered asymmetric hybrid fiber membrane according to any one of claims 1 to 4, characterized in that: The steps include: 1) The piezoelectric polymer is dissolved in an organic solvent to obtain a spinning solution, and then the spinning solution is electrospinned to produce a bottom piezoelectric fiber membrane; 2) Dissolving a hydrophobic polymer and gelatin in an acetic acid solution and stirring uniformly, and doping with an inorganic conductive nanomaterial to obtain a spinning solution for the core layer, which is then electrospun onto the underlying fiber membrane to obtain a core layer conductive fiber membrane; 3) A water-soluble polymer and chitosan are dissolved in an acetic acid solution to obtain a surface spinning solution, which is then electrospun onto the bottom and core conductive fiber membranes to produce a surface fiber membrane, ultimately yielding an antibacterial, hemostatic, and self-powered asymmetric hybrid fiber membrane.

6. The preparation method according to claim 5, characterized in that: In step 1), the piezoelectric polymer is polyvinylidene fluoride; the organic solvent is selected from one or more of N,N-dimethylformamide, acetone, dimethyl sulfoxide, and acetic acid; In step 1), the mass concentration of the piezoelectric polymer is 5-20%, and the dissolution temperature is 30-50°C; In step 1), the electrospinning process parameters are: voltage 15-25 kV, receiving distance 16-23 cm, spinning solution feed rate 0.001-0.02 mL / min; spinning environment conditions are temperature 32±6°C and humidity 40±10%.

7. The preparation method according to claim 5, characterized in that: In step 2), the hydrophobic polymer is selected from one or more of polycaprolactone, polyurethane, and polylactic acid-glycolic acid copolymer.

8. The preparation method according to claim 5, characterized in that: In step 2), the inorganic conductive nanomaterial is selected from one or more of copper nanoparticles, carbon nanotubes, silver nanowires, and gold nanoparticles.

9. The preparation method according to claim 5, characterized in that: In step 2), the total mass fraction of the hydrophobic polymer and gelatin is 10-30%, the mass ratio of the hydrophobic polymer to gelatin is 4:1-1:4, the mass concentration of the acetic acid solution is 75-85%; and the solute of the inorganic conductive nanomaterial accounts for 1-10%.

10. The preparation method according to claim 5, characterized in that: In step 2), the spinning process parameters based on the bottom fiber membrane are: voltage 12~22 kV, receiving distance 18~22 cm, spinning solution feed rate 0.001~0.01 mL / min; spinning environment conditions are temperature 32±6°C and humidity 48±5%.

11. The preparation method according to claim 5, characterized in that: In step 3), the water-soluble polymer is selected from one or more of polyvinyl alcohol, polyethylene oxide, and polyvinyl pyrrolidone.

12. The preparation method according to claim 5, characterized in that: In step 3), the total mass fraction of the water-soluble polymer and chitosan is 1-4%, the mass ratio of the water-soluble polymer to chitosan is 1:9-1:1, and the mass concentration of the acetic acid solution is 45-55%.

13. The preparation method according to claim 5, characterized in that: In step 3), the process parameters for spinning on the basis of the bottom layer and core layer fiber membrane are: voltage 12~22 kV, receiving distance 18~22 cm, spinning solution feed rate 0.001~0.01 mL / min; spinning environment conditions are temperature 30±6°C and humidity 45±5%.

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