An antibacterial biomimetic absorbable wound dressing and a method of making the same

Abstract

The application relates to an antibacterial bionic absorbable wound dressing and a preparation method thereof, and comprises the following steps: (1) preparing a spinning precursor solution: 10-15 wt% of a decellularized extracellular matrix, 3-10 wt% of a natural polymer material, 0.1-3 wt% of a crosslinking agent, and the rest being glacial acetic acid; preparing a spray dispersion liquid: 0.15-2.5 wt% of antibacterial nanoparticles, 0.1-1 wt% of a crosslinking agent, and the rest being an alcohol solvent; the antibacterial nanoparticles are a composite of a natural polymer material embedding antibacterial drugs; (2) placing the spinning precursor solution in an electrostatic spinning injector, placing the spray dispersion liquid in an electrostatic spraying injector, simultaneously carrying out electrostatic spinning and electrostatic spraying after the power is turned on, and obtaining an antibacterial nanofiber membrane on a receiving device; (3) drying and crosslinking the antibacterial nanofiber membrane to obtain the antibacterial bionic absorbable wound dressing, and the microstructure is that the surface of each nanofiber uniformly loads the antibacterial nanoparticles. The dressing is beneficial to cell adhesion and achieves the effect of antibacterial particle slow release.

Description

Technical Field

[0001] This invention relates to the field of biomedical materials technology, specifically to an antibacterial biomimetic absorbable wound dressing and its preparation method. Background Technology

[0002] Medical wound dressings play a vital role in wound care and treatment by covering damaged skin and providing a favorable microenvironment for wound healing. Currently, most medical dressings still use traditional cotton gauze, which requires frequent changes and easily adheres to the wound, potentially leading to secondary tissue trauma and bacterial growth. Furthermore, the significant waste of dressings causes environmental harm. Therefore, there is an urgent need to design novel, biodegradable, and biocompatible medical wound dressings with good antibacterial activity.

[0003] Ideal wound dressings should possess functions such as antibacterial properties, hemostasis, biocompatibility, biodegradability, and promotion of tissue regeneration. With the widespread clinical acceptance of the "moist wound healing" theory, some modern novel dressings, such as hydrogel dressings, alginate dressings, and silver ion dressings, have been applied clinically. These dressings interact with the wound surface, absorbing secretions and allowing oxygen to enter, thus positively promoting wound healing. In recent years, advancements in tissue engineering have led to the emergence of various biological scaffolds, including electrospun nanofibers, as wound dressings. The human body's natural extracellular matrix has a nanofiber structure, which facilitates cell adhesion. Biomimetic wound dressings with nanofiber structures provide physical signals to cells and guide cell functionalization.

[0004] Electrospinning is a preferred and mature technology for preparing nanofiber structures, offering advantages such as simple operation and controllable fiber morphology, structure, and size. Electrospun nanofiber wound dressings possess advantages such as a three-dimensional support structure, small pore size, and large specific surface area, better mimicking the extracellular matrix than traditional dressings, thus promoting cell growth, adhesion, and proliferation, and effectively isolating pathogenic microorganisms from the external environment. However, this unique structure also makes it susceptible to pathogen adhesion; therefore, the preparation of electrospun scaffolds with antibacterial functions has become a key focus of current research and technological breakthroughs. In addition to biomimetic nanofiber structures, biomimetic composition should also be considered.

[0005] Current technologies still present many challenges. For example, in antibacterial modification, antibacterial nanoparticles are simply suspended in the spinning precursor and then blended. While this method is simple, it has drawbacks, such as nanoparticle aggregation and embedding within the fiber, resulting in low antibacterial efficiency. Surface impregnation, while able to adhere nanoparticles to the fiber surface to a large extent, suffers from uneven antibacterial effects due to the hierarchical fiber accumulation during electrospinning, causing a gradient distribution of antibacterial nanoparticles between the surface and interior of the fiber membrane. Spraying can achieve a certain degree of uniform dispersion of antibacterial particles on the fiber surface, but the adhesion between the antibacterial particles and nanofibers is poor, leading to easy detachment. Summary of the Invention

[0006] The technical problem this invention aims to solve is how to uniformly disperse and load antibacterial particles on the fiber surface while maintaining adhesion to achieve a sustained-release effect. To address this, this invention provides an antibacterial biomimetic absorbable wound dressing and its preparation method. This invention combines electrospinning and electrospraying to enable the antibacterial nanoparticles to be uniformly dispersed, loaded, and adhered to the nanofiber surface. This results in a biomimetic dressing with favorable cell adhesion, thus achieving a sustained-release effect of the antibacterial particles.

[0007] To achieve the above objectives, the present invention is implemented through the following technical solution:

[0008] A method for preparing an antibacterial, biomimetic, absorbable wound dressing includes the following steps:

[0009] (1) Prepare a spinning precursor solution, comprising the following raw materials in 100wt%: 10-15wt% decellularized extracellular matrix, 3-10wt% natural polymer material, 0.1-3wt% crosslinking agent, and the balance being glacial acetic acid;

[0010] The spray dispersion is prepared by comprising the following 100wt% raw materials: 0.15-2.5wt% antibacterial nanoparticles, 0.1-1wt% crosslinking agent, and the balance being an alcohol solvent; wherein the antibacterial nanoparticles are a complex of natural polymer materials encapsulating antibacterial drugs.

[0011] (2) The spinning precursor solution is placed in an electrospinning injector, the spray dispersion is placed in an electrospinning injector, the power is turned on and electrospinning and electrospinning are performed simultaneously, and an antibacterial nanofiber membrane is obtained on a receiving device.

[0012] (3) The antibacterial nanofiber membrane is dried, and cross-linking occurs during the drying process to obtain an antibacterial biomimetic absorbable wound dressing. The surface of each nanofiber of the antibacterial biomimetic absorbable wound dressing is uniformly loaded with the antibacterial nanoparticles.

[0013] Furthermore, the preparation process of the spinning precursor solution is as follows: first, the decellularized extracellular matrix and the natural polymer material are mixed in proportion, then dissolved in the glacial acetic acid, and the crosslinking agent is added and mixed for 5-15 minutes.

[0014] Further, the process for obtaining the antibacterial nanoparticles is as follows: An antibacterial drug is added to an aqueous solution containing dissolved or swollen natural polymer materials. After uniform dispersion, a composite solution is obtained. The composite solution is then stirred and mixed with an oil-phase solvent, and the pH of the system is adjusted to 4-6.5 to carry out a precipitation reaction. The resulting precipitate is collected as antibacterial nanoparticles. The antibacterial nanoparticles are a composite material in which the antibacterial drug is encapsulated within a natural polymer material, wherein the mass ratio of the antibacterial drug to the natural polymer material is (0.01-0.1):(5-15). This composite material enables the sprayed antibacterial nanoparticles to be uniformly loaded onto the surface of the nanofibers formed by electrospinning during the electrostatic spraying process. During the subsequent drying process, interfacial cross-linking occurs, allowing the antibacterial nanoparticles to firmly adhere to the nanofiber surface.

[0015] Preferably, the composite liquid contains 5-15 wt% natural polymer materials, 0.01-0.1 wt% antibacterial drugs, and the balance is water; the volume ratio of the composite liquid to the oil phase solvent is 1:(1-4), and the precipitation reaction time is 20-35 h; the oil phase solvent is one or more of chloroform, dichloromethane, and liquid paraffin.

[0016] Furthermore, the preparation process of the spray dispersion is as follows: the antibacterial nanoparticles are dispersed in an alcohol solvent, and the crosslinking agent is added and mixed for 20-40 minutes.

[0017] Furthermore, the decellularized extracellular matrix is ​​obtained by digesting and freeze-drying the decellularized extracellular matrix.

[0018] Furthermore, the natural polymer material is one or more of chitosan, hyaluronic acid, collagen, gelatin, or silk fibroin; the crosslinking agent is one or more of formaldehyde, glutaraldehyde, paraformaldehyde, or transglutaminase; the antibacterial drug is one or more of azithromycin, gentamicin sulfate, amoxicillin, or penicillin; and the alcohol solvent is one or more of methanol, ethanol, or isopropanol.

[0019] Furthermore, each nanofiber of the antibacterial nanofiber membrane has a diameter of 100-900 nm, and antibacterial nanoparticles are uniformly adhered to the surface of each nanofiber, with a particle size of 30-90 nm.

[0020] Furthermore, the parameters for electrospinning and electrospraying are as follows: a positive voltage of 15-25 kV is applied to the needle of the electrospinning injector, a positive voltage of 10-20 kV is applied to the needle of the electrospray injector, a negative voltage of 0.5-3 kV is applied to the receiving device, the needles of the electrospinning injector and the electrospray injector are 10-15 cm away from the receiving device, the injection flow rate of the spinning precursor solution is 1-4 mL / h, the injection flow rate of the spray dispersion is 0.5-3 mL / h, and the rotation speed of the receiving device is 100-200 rpm.

[0021] An antibacterial biomimetic absorbable wound dressing was prepared by the above method.

[0022] Beneficial technical effects: This invention uses natural polymer materials and decellularized extracellular matrix as the nanofiber skeleton for electrospun fabrication. Simultaneously, antibacterial nanoparticles are uniformly loaded onto the surface of the nanofiber skeleton using electrostatic spraying. During the subsequent drying process, the antibacterial nanoparticles undergo interfacial cross-linking with the nanofibers, thereby achieving firm adhesion of the antibacterial nanoparticles to the nanofiber surface. Furthermore, the structure of the antibacterial nanoparticles in this invention involves a complex of antibacterial drugs encapsulated in natural polymer materials, which can be uniformly loaded onto the nanofiber skeleton surface. This structure facilitates improved interfacial adhesion between the antibacterial nanoparticles and the nanofiber skeleton during cross-linking, achieving stable adhesion and dispersion of the antibacterial nanoparticles on the nanofiber surface and during the stacking process. The dressing of this invention has a suitable sustained-release rate of antibacterial drugs, which can promote wound healing and reduce scar growth. During wound healing, the antibacterial drugs are released at an appropriate rate to achieve a better antibacterial effect. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the process apparatus for preparing antibacterial nanofiber membranes using electrospinning and electrostatic spraying according to the present invention, wherein 11-electrospinning injector, 12-electrostatic spraying injector, 2-spinning precursor solution, 3-spray dispersion, 4-receiving device, and 5-power supply.

[0024] Figure 2 This is a scanning electron microscope image of the antibacterial biomimetic absorbable wound dressing prepared in Example 1.

[0025] Figure 3 This is a scanning electron microscope image of the antibacterial biomimetic absorbable wound dressing prepared in Example 2.

[0026] Figure 4 This is a scanning electron microscope image of the antibacterial biomimetic absorbable wound dressing prepared in Example 3. Detailed Implementation

[0027] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments and accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0028] Unless otherwise specifically stated, the numerical values ​​set forth in these embodiments do not limit the scope of the invention. Techniques and methods known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques and methods should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0029] Experimental methods not specifically described in the following examples are generally determined according to national standards; if no corresponding national standard exists, they are performed according to generally accepted international standards or the standards proposed by relevant enterprises. Unless otherwise stated, all parts are parts by weight, and all percentages are weight percentages.

[0030] Example 1

[0031] A method for preparing an antibacterial, biomimetic, absorbable wound dressing includes the following steps:

[0032] (1) Preparation of working solution:

[0033] A. Preparation of spinning precursor solution:

[0034] The spinning precursor solution consists of the following 100wt% raw materials: 15wt% decellularized extracellular matrix, 5wt% gelatin, 0.1wt% glutaraldehyde, and the balance being glacial acetic acid. The preparation process of the spinning precursor solution is as follows: first, the obtained decellularized extracellular matrix and gelatin are mixed at a mass ratio of 3:1, then dissolved in glacial acetic acid, and glutaraldehyde is added and mixed for 10 min to obtain the spinning precursor solution.

[0035] The process for obtaining decellularized extracellular matrix is ​​as follows: pepsin and decellularized extracellular matrix are added to a 0.01M hydrochloric acid solution. The concentration of pepsin in the hydrochloric acid solution is 1 wt%, and the concentration of extracellular matrix in the hydrochloric acid solution is 10 mg / mL. After adding them in proportion, the mixture is shaken and digested until completely dissolved. The pH of the system is then adjusted to neutral with a 0.1M sodium hydroxide solution, and the solution is freeze-dried to obtain powdered decellularized extracellular matrix.

[0036] B. Preparation of spray dispersion:

[0037] The spray dispersion comprises the following raw materials in 100 wt% form: 0.16 wt% antibacterial nanoparticles, 0.2 wt% glutaraldehyde, and the balance being anhydrous ethanol; wherein the antibacterial nanoparticles are a complex of gelatin-encapsulated gentamicin sulfate, wherein the mass ratio of gentamicin sulfate to gelatin is 0.05:10.

[0038] The preparation process of antibacterial nanoparticles is as follows: gelatin is dissolved in water and stirred evenly to form a gelatin aqueous solution with a concentration of 10 wt%. Gentamicin sulfate is then added to the gelatin aqueous solution at a concentration of 0.05 wt%. After being dispersed evenly, a composite solution is obtained. The composite solution is mixed with dichloromethane at a volume ratio of 1:1.5 and magnetically stirred at 1400 rpm. The pH of the system is adjusted to 5.5 to induce a precipitation reaction. After stirring for 24 hours, the precipitate is collected by centrifugation and is identified as antibacterial nanoparticles, which is the gelatin-encapsulated gentamicin sulfate complex.

[0039] Preparation of spray dispersion: The antibacterial nanoparticles are dispersed in anhydrous ethanol in a certain proportion, and glutaraldehyde is added and mixed for 30 min to obtain the spray dispersion.

[0040] (2) According to Figure 1 The process apparatus places the spinning precursor solution 2 in an electrospinning injector 11 and the spray dispersion 3 in an electrospinning injector 12. After turning on the power supply 5, electrospinning and electrospinning are performed simultaneously. The parameters are as follows: a positive voltage of 23 kV is applied to the needle of the electrospinning injector 11, a positive voltage of 10 kV is applied to the needle of the electrospinning injector 12, a negative voltage of 1 kV is applied to the receiving device 4, the needles of the electrospinning injector 11 and the electrospinning injector 12 are 14 cm away from the receiving device 4, the injection flow rate of the spinning precursor solution 2 is 1 mL / h, the injection flow rate of the spray dispersion 3 is 0.5 mL / h, and the rotation speed of the receiving device 4 is 100 rpm. Thus, an antibacterial nanofiber membrane is obtained on the receiving device 4. SEM observation shows that the surface of each nanofiber of the antibacterial nanofiber membrane is uniformly loaded with antibacterial nanoparticles.

[0041] (3) The antibacterial nanofiber membrane is placed in a vacuum oven at 80°C and dried for 7 hours. During the drying process, interfacial cross-linking between antibacterial nanoparticles and nanofibers is generated, and the antibacterial nanoparticles and nanofibers are tightly bonded to the surface, thereby obtaining an antibacterial biomimetic absorbable wound dressing. Then it is packaged and sterilized with ethylene oxide.

[0042] The SEM image of the antibacterial biomimetic absorbable wound dressing prepared in this embodiment is shown below. Figure 2 As shown, by Figure 2It can be seen that after drying and cross-linking, the surface morphology of the antibacterial nanofiber membrane did not change significantly. The antibacterial nanoparticles were uniformly dispersed and attached to the nanofiber skeleton, and the surface of each nanofiber was uniformly attached with antibacterial nanoparticles. The nanofiber diameter was about 100-900 nm and the particle size of the antibacterial nanoparticles was about 30-90 nm.

[0043] Example 2

[0044] A method for preparing an antibacterial, biomimetic, absorbable wound dressing includes the following steps:

[0045] (1) Preparation of working solution:

[0046] A. Preparation of spinning precursor solution:

[0047] The spinning precursor solution consists of the following 100wt% raw materials: 15wt% decellularized extracellular matrix, 5wt% gelatin, 0.1wt% glutaraldehyde, and the balance being glacial acetic acid. The preparation process of the spinning precursor solution is as follows: first, the obtained decellularized extracellular matrix and gelatin are mixed at a mass ratio of 3:1, then dissolved in glacial acetic acid, and glutaraldehyde is added and mixed for 10 min to obtain the spinning precursor solution.

[0048] The process of obtaining the decellularized extracellular matrix is ​​the same as that in Example 1;

[0049] B. Preparation of spray dispersion:

[0050] The spray dispersion comprises the following raw materials in 100 wt% form: 0.16 wt% antibacterial nanoparticles, 0.2 wt% glutaraldehyde, and the balance being anhydrous ethanol; wherein the antibacterial nanoparticles are a complex of gelatin-encapsulated gentamicin sulfate, wherein the mass ratio of gentamicin sulfate to gelatin is 0.1:10.

[0051] The preparation process of antibacterial nanoparticles is as follows: gelatin is dissolved in water and stirred evenly to form a gelatin aqueous solution with a concentration of 10 wt%. Gentamicin sulfate is then added to the gelatin aqueous solution at a concentration of 0.1 wt%. After being dispersed evenly, a composite solution is obtained. The composite solution is mixed with dichloromethane at a volume ratio of 1:1.5 and magnetically stirred at 1400 rpm. The pH of the system is adjusted to 5.5 to induce a precipitation reaction. After stirring for 24 hours, the precipitate is collected by centrifugation and is identified as antibacterial nanoparticles, which is the gelatin-encapsulated gentamicin sulfate complex.

[0052] Preparation of spray dispersion: The antibacterial nanoparticles are dispersed in anhydrous ethanol in a certain proportion, and glutaraldehyde is added and mixed for 30 min to obtain the spray dispersion.

[0053] (2) According to Figure 1The process apparatus places the spinning precursor solution 2 in an electrospinning injector 11 and the spray dispersion 3 in an electrospinning injector 12. After turning on the power supply 5, electrospinning and electrospinning are performed simultaneously. The parameters are as follows: a positive voltage of 23 kV is applied to the needle of the electrospinning injector 11, a positive voltage of 10 kV is applied to the needle of the electrospinning injector 12, a negative voltage of 1 kV is applied to the receiving device 4, the needles of the electrospinning injector 11 and the electrospinning injector 12 are 14 cm away from the receiving device 4, the injection flow rate of the spinning precursor solution 2 is 1 mL / h, the injection flow rate of the spray dispersion 3 is 0.5 mL / h, and the rotation speed of the receiving device 4 is 100 rpm. Thus, an antibacterial nanofiber membrane is obtained on the receiving device 4. SEM observation shows that the surface of each nanofiber of the antibacterial nanofiber membrane is uniformly loaded with antibacterial nanoparticles.

[0054] (3) The antibacterial nanofiber membrane is placed in a vacuum oven at 80°C and dried for 7 hours. During the drying process, interfacial cross-linking between antibacterial nanoparticles and nanofibers is generated, and the antibacterial nanoparticles and nanofibers are tightly bonded to the surface, thereby obtaining an antibacterial biomimetic absorbable wound dressing. Then it is packaged and sterilized with ethylene oxide.

[0055] The SEM image of the antibacterial biomimetic absorbable wound dressing prepared in this embodiment is shown below. Figure 3 As shown, by Figure 3 It can be seen that after drying and cross-linking, the surface morphology of the antibacterial nanofiber membrane did not change significantly. The antibacterial nanoparticles were uniformly dispersed and attached to the nanofiber skeleton, and the surface of each nanofiber was uniformly attached with antibacterial nanoparticles. The nanofiber diameter was about 100-900 nm and the particle size of the antibacterial nanoparticles was about 30-90 nm.

[0056] Example 3

[0057] A method for preparing an antibacterial, biomimetic, absorbable wound dressing includes the following steps:

[0058] (1) Preparation of working solution:

[0059] A. Preparation of spinning precursor solution:

[0060] The spinning precursor solution consists of the following 100wt% raw materials: 15wt% decellularized extracellular matrix, 5wt% gelatin, 0.1wt% glutaraldehyde, and the balance being glacial acetic acid. The preparation process of the spinning precursor solution is as follows: first, the obtained decellularized extracellular matrix and gelatin are mixed at a mass ratio of 3:1, then dissolved in glacial acetic acid, and glutaraldehyde is added and mixed for 10 min to obtain the spinning precursor solution.

[0061] The process of obtaining the decellularized extracellular matrix is ​​the same as that in Example 1;

[0062] B. Preparation of spray dispersion:

[0063] The spray dispersion comprises the following raw materials in 100 wt% form: 0.16 wt% antibacterial nanoparticles, 0.4 wt% glutaraldehyde, and the balance being anhydrous ethanol; wherein the antibacterial nanoparticles are a complex of gelatin-encapsulated gentamicin sulfate, wherein the mass ratio of gentamicin sulfate to gelatin is 0.05:10.

[0064] The preparation process of antibacterial nanoparticles is as follows: gelatin is dissolved in water and stirred evenly to form a gelatin aqueous solution with a concentration of 10 wt%. Gentamicin sulfate is then added to the gelatin aqueous solution at a concentration of 0.05 wt%. After being dispersed evenly, a composite solution is obtained. The composite solution is mixed with dichloromethane at a volume ratio of 1:1.5 and magnetically stirred at 1400 rpm. The pH of the system is adjusted to 5.5 to induce a precipitation reaction. After stirring for 24 hours, the precipitate is collected by centrifugation and is identified as antibacterial nanoparticles, which is the gelatin-encapsulated gentamicin sulfate complex.

[0065] Preparation of spray dispersion: The antibacterial nanoparticles are dispersed in anhydrous ethanol in a certain proportion, and glutaraldehyde is added and mixed for 30 min to obtain the spray dispersion.

[0066] (2) According to Figure 1 The process apparatus places the spinning precursor solution 2 in an electrospinning injector 11 and the spray dispersion 3 in an electrospinning injector 12. After turning on the power supply 5, electrospinning and electrospinning are performed simultaneously. The parameters are as follows: a positive voltage of 23 kV is applied to the needle of the electrospinning injector 11, a positive voltage of 10 kV is applied to the needle of the electrospinning injector 12, a negative voltage of 1 kV is applied to the receiving device 4, the needles of the electrospinning injector 11 and the electrospinning injector 12 are 14 cm away from the receiving device 4, the injection flow rate of the spinning precursor solution 2 is 1 mL / h, the injection flow rate of the spray dispersion 3 is 0.5 mL / h, and the rotation speed of the receiving device 4 is 100 rpm. Thus, an antibacterial nanofiber membrane is obtained on the receiving device 4. SEM observation shows that the surface of each nanofiber of the antibacterial nanofiber membrane is uniformly loaded with antibacterial nanoparticles.

[0067] (3) The antibacterial nanofiber membrane is placed in a vacuum oven at 80°C and dried for 7 hours. During the drying process, interfacial cross-linking between antibacterial nanoparticles and nanofibers is generated, and the antibacterial nanoparticles and nanofibers are tightly bonded to the surface, thereby obtaining an antibacterial biomimetic absorbable wound dressing. Then it is packaged and sterilized with ethylene oxide.

[0068] The SEM image of the antibacterial biomimetic absorbable wound dressing prepared in this embodiment is shown below. Figure 4 As shown, by Figure 4It can be seen that after drying and cross-linking, the surface morphology of the antibacterial nanofiber membrane did not change significantly. The antibacterial nanoparticles were uniformly dispersed and attached to the nanofiber skeleton, and the surface of each nanofiber was uniformly attached with antibacterial nanoparticles. The nanofiber diameter was about 100-900 nm and the particle size of the antibacterial nanoparticles was about 30-90 nm.

[0069] Compare with Example 1

[0070] The spinning precursor solution and antibacterial nanoparticles were prepared according to the operation method in Example 1. Then, the antibacterial nanoparticles were mixed with the spinning precursor solution, and electrospinning was performed according to the following process: a positive voltage of 23 kV was applied to the needle of the electrospinning syringe, a negative voltage of 1 kV was applied to the receiving device, the working distance between the needle of the electrospinning syringe and the receiving device was 14 cm, the injection flow rate of the spinning precursor solution was 1 mL / h, and the rotation speed of the receiving device was 100 rpm. An electrospinned membrane was obtained and dried in a vacuum oven.

[0071] The comparative product is denoted as a traditional blended spinning film.

[0072] Compare with Example 2

[0073] The spinning precursor solution and antibacterial nanoparticles were prepared according to the operation method in Example 1. The spinning precursor solution was electrospun according to the following process: a positive voltage of 23 kV was applied to the needle of the electrospinning syringe, a negative voltage of 1 kV was applied to the receiving device, the working distance between the needle of the electrospinning syringe and the receiving device was 14 cm, the injection flow rate of the spinning precursor solution was 1 mL / h, and the rotation speed of the receiving device was 100 rpm, thus obtaining an electrospun membrane.

[0074] The prepared antibacterial nanoparticles were mixed with anhydrous ethanol in the proportion of Example 1 to obtain an impregnation solution. The prepared electrospun membrane was then immersed in the impregnation solution for 5 minutes and then dried in a vacuum oven.

[0075] The comparative product is referred to as impregnated film.

[0076] Compare with Example 3

[0077] The spinning precursor solution and electrostatic spray dispersion were prepared according to the operation method in Example 1, wherein the spray dispersion did not contain glutaraldehyde. Subsequently, the fiber membrane was prepared according to the process parameters of electrospinning and electrostatic spraying in Example 1 and dried in a vacuum oven.

[0078] The sustained-release performance of the membranes from the above examples and control examples was tested: The membranes prepared above were cut into rectangular membranes of the same size, approximately the same thickness, and weighing about 30 mg. These were placed in centrifuge tubes, and 20 mL of phosphate buffer solution was added to each tube. The centrifuge tubes were then placed in a constant-temperature air shaker at 37°C and a shaking frequency of 120 times / min. Samples were taken at time intervals of 2, 4, 6, 8, 10, 12, 14, and 16 days. Each time, 3 mL of solution was taken from the centrifuge tube for testing, and then 3 mL of fresh medium was added to the centrifuge tube, and shaking continued. The absorbance at λ = 248 nm was measured using a UV-Vis spectrophotometer, and the concentration of gentamicin sulfate in the solution was calculated from the standard curve. The results are shown in Table 1.

[0079] Table 1. Comparison of drug release from membranes over days in the examples and control examples.

[0080]

[0081] Table 1 shows that the sustained-release time of the drug is affected by the drug loading content and the degree of cross-linking. Compared with Example 3, Example 3 increased the use of a cross-linking agent in the spray dispersion, which increased the interfacial cross-linking density between the antibacterial nanoparticles and nanofibers in the later stage. As a result, the sustained-release drug amount of the product in Example 3 was smaller than that of the product in Example 1. Therefore, when the drug loading content is the same, the higher the degree of cross-linking, the more difficult it is for the phosphate buffer to destroy the interface, thereby reducing the drug release rate. Compared with Example 2, the drug loading content of the product in Example 2 is higher than that of the product in Example 1. Under the same degree of cross-linking, the higher the drug loading content, the greater the release. In addition, the total drug release rate of the product in Example 1 was more than 95% by day 22, the total drug release rate of the product in Example 2 was more than 95% by day 28, and the total drug release rate of the product in Example 3 was more than 95% by day 30.

[0082] Comparative Example 1 is a traditional blended spun membrane. Its microstructure consists of antibacterial nanoparticles embedded within a framework of decellularized extracellular matrix / gelatin nanofibers. In other words, the antibacterial nanoparticles are located inside the nanofibers, not on their surface. Therefore, the sustained-release effect of the traditional blended spun membrane in Comparative Example 1 is slightly better than that of the membrane in Example 1. However, because the antibacterial nanoparticles are embedded in proteins, the drug release rate is very slow, resulting in lower antibacterial efficiency. The total drug release rate of the product in Comparative Example 1 was over 95% by day 32.

[0083] Comparative Example 2 was an impregnated film, and Comparative Example 3 did not add a crosslinking agent to the spray dispersion. Due to the weak adhesion between the antibacterial nanoparticles and nanofibers, both of them exhibited obvious drug burst release behavior, releasing almost all of the drug within a short period of time. By day 8, the product of Comparative Example 2 had released approximately 96% of the drug, and by day 10, the product of Comparative Example 3 had released approximately 95% of the drug.

[0084] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A method for preparing an antibacterial, biomimetic, absorbable wound dressing, characterized in that, Includes the following steps: (1) Prepare a spinning precursor solution, comprising the following raw materials in 100wt%: 10-15wt% decellularized extracellular matrix, 3-10wt% natural polymer material, 0.1-3wt% crosslinking agent, and the balance being glacial acetic acid; The spray dispersion is prepared by comprising the following 100wt% raw materials: 0.15-2.5wt% antibacterial nanoparticles, 0.1-1wt% crosslinking agent, and the balance being an alcohol solvent; The natural polymer material is gelatin; the crosslinking agent is glutaraldehyde. The process for obtaining the antibacterial nanoparticles is as follows: an antibacterial drug is added to an aqueous solution containing dissolved or swollen natural polymer materials, and after uniform dispersion, a composite solution is obtained. The composite solution is stirred and mixed with an oil phase solvent, and the pH of the system is adjusted to 4-6.5 to carry out a precipitation reaction. The precipitate obtained is the antibacterial nanoparticles. The antibacterial nanoparticles are a composite material in which the antibacterial drug is encapsulated in a natural polymer material, wherein the mass ratio of the antibacterial drug to the natural polymer material is (0.01-0.1):(5-15). (2) The spinning precursor solution is placed in an electrospinning injector, and the spray dispersion is placed in an electrospinning injector. After turning on the power, electrospinning and electrospinning are performed simultaneously, and an antibacterial nanofiber membrane is obtained on a receiving device. Each nanofiber of the antibacterial nanofiber membrane has a diameter of 100-900 nm, and antibacterial nanoparticles are uniformly adhered to the surface of each nanofiber. The particle size of the antibacterial nanoparticles is 30-90 nm. The parameters for electrospinning and electrospraying are as follows: the needle of the electrospinning injector is applied with a positive voltage of 15-25kV, the needle of the electrospray injector is applied with a positive voltage of 10-20kV, the receiving device is applied with a negative voltage of 0.5-3kV, the needles of the electrospinning injector and the electrospray injector are 10-15cm away from the receiving device, the injection flow rate of the spinning precursor solution is 1-4mL / h, the injection flow rate of the spray dispersion is 0.5-3mL / h, and the rotation speed of the receiving device is 100-200rpm. (3) The antibacterial nanofiber membrane is dried, and cross-linking occurs during the drying process to obtain an antibacterial biomimetic absorbable wound dressing. The antibacterial nanoparticles are uniformly loaded on the surface of each nanofiber of the antibacterial biomimetic absorbable wound dressing.

2. The method for preparing an antibacterial biomimetic absorbable wound dressing according to claim 1, characterized in that, The preparation process of the spinning precursor solution is as follows: first, the decellularized extracellular matrix and the natural polymer material are mixed in proportion, then dissolved in glacial acetic acid, and the crosslinking agent is added and mixed for 5-15 minutes.

3. The method for preparing an antibacterial biomimetic absorbable wound dressing according to claim 1, characterized in that, The composite liquid contains 5-15 wt% natural polymer materials, 0.01-0.1 wt% antibacterial drugs, and the balance is water; the volume ratio of the composite liquid to the oil phase solvent is 1:(1-4), and the precipitation reaction time is 20-35 h; the oil phase solvent is one or more of chloroform, dichloromethane, and liquid paraffin.

4. The method for preparing an antibacterial biomimetic absorbable wound dressing according to claim 1, characterized in that, The preparation process of the spray dispersion is as follows: the antibacterial nanoparticles are dispersed in an alcohol solvent, and the crosslinking agent is added and mixed for 20-40 minutes.

5. The method for preparing an antibacterial biomimetic absorbable wound dressing according to claim 1, characterized in that, The decellularized extracellular matrix is ​​obtained by digesting and freeze-drying the decellularized extracellular matrix.

6. A method for preparing an antibacterial biomimetic absorbable wound dressing according to any one of claims 1-5, characterized in that, The antibacterial drug is one or more of azithromycin, gentamicin sulfate, amoxicillin, and penicillin; the alcohol solvent is one or more of methanol, ethanol, and isopropanol.

7. An antibacterial biomimetic absorbable wound dressing prepared by the method according to any one of claims 1-6.

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