CN106620813A - Preparation method of medical antibacterial nano dressing - Google Patents

Abstract

The invention relates to a preparation method of a medical antibacterial nano dressing, which comprises the following steps: dissolving polylactic acid in an organic solvent to obtain a polylactic acid solution with a concentration of 6wt%-10wt%; dissolving chitosan in acid to obtain a mass fraction of 2wt%-5wt% chitosan solution; mix polylactic acid solution and chitosan solution, then add Yunnan Baiyao and silver salt to the mixed solution, and stir evenly under dark conditions to obtain an electrospinning solution; electrospinning The solution is electrospun to obtain a medical antibacterial nano dressing. The invention adopts electrospinning technology to prepare nano-scale drug-loaded nanofiber membranes, uses polylactic acid with good biocompatibility and chitosan with bactericidal properties as basic materials, and uses Yunnan Baiyao and silver as additional components, combining the four Advantages, providing a new type of medical nano antibacterial dressing with better curative effect.

Description

Preparation method of medical antibacterial nanometer dressing

technical field

The invention relates to the technical field of preparation of medical materials, in particular to a preparation method of a medical antibacterial nanometer dressing.

Background technique

Electrospinning is a simple and low-cost method for continuous fabrication of nanofibers. Nanofibers prepared by electrospinning have a large specific surface area, and porous nanofibers are widely used in biomedicine due to their higher specific surface area and good performance, including wound dressings, drug sustained release carriers, tissue engineering, etc. Wait.

Polylactic acid has good biocompatibility and biodegradability, its degradation products can be absorbed by the body, and has good mechanical properties, so it has a wide range of applications in the field of biomedicine. However, the polylactic acid structure contains a large number of ester bonds, which has weak adhesion to cells, and the acidic environment during its degradation process will lead to sterile inflammatory reactions. Chitosan's properties of hemostasis, antibacterial, antibacterial, biocompatibility, promotion of wound healing, and easy gel formation all endow it with good performance as a hemostatic dressing or hemostatic agent. effect. However, the pure chitosan film is brittle and has poor mechanical properties. Combined with the excellent mechanical properties of polylactic acid, the blending of the two as the basic material can complement each other.

Yunnan Baiyao is composed of a variety of precious medicinal materials, which has the miraculous effects of reducing fatigue and stopping bleeding, promoting blood circulation and removing blood stasis, anti-inflammatory and healing wounds, reducing putrefaction and promoting muscle growth. Modern pharmacological studies have shown that Yunnan Baiyao can not only enhance the activation rate of platelets, accelerate the aggregation of platelets to the wound surface, shorten the bleeding and coagulation time, and inhibit the bleeding from the wound surface; it can also reduce blood density, accelerate microcirculation, and prevent thrombus formation. Therefore, Yunnan Baiyao has broad application prospects in the dressing field.

In addition, silver has excellent broad-spectrum antibacterial ability and has no toxic side effects to humans, so it can be widely used as an antibacterial and anti-inflammatory agent. The preparation of silver-containing nanofibers by electrospinning can achieve uniform and slow release of silver ions, thereby achieving a long-lasting bactericidal effect. By slowly releasing the silver ions in the dressing, it is expected to achieve a continuous sterilization and anti-inflammatory effect on the wound.

Dressings are a class of medical materials that can temporarily protect wounds, prevent external germs from invading, and promote healing. Traditional dressings such as gauze, sponge pads, etc. also have some problems in clinical use. For example, the existing dressings can only bandage the wound, do not contain pharmaceutical ingredients, and have poor hygroscopicity and air permeability. Wound dressings are mostly materials such as vaseline gauze, iodophor gauze and non-woven fabrics, which are used to clean and protect the wound surface. However, these materials still cannot meet the needs of clinical treatment in terms of efficient antibacterial, reducing wound infection, and promoting wound healing.

Contents of the invention

In order to solve the above-mentioned technical problems, the purpose of the present invention is to provide a preparation method of medical antibacterial nano dressing, which uses electrospinning technology to prepare nano-scale drug-loaded nanofiber membranes, adopts polylactic acid with good biocompatibility and has bactericidal properties. Performance Chitosan is used as the basic material, and Yunnan Baiyao and silver are used as the added components. Combining the advantages of the four, a new type of medical nano-antibacterial dressing with better curative effect is provided.

The preparation method of medical antibacterial nanometer dressing of the present invention, comprises the following steps:

(1) dissolving polylactic acid in an organic solvent to obtain a polylactic acid solution with a concentration of 6wt%-10wt%;

(2) chitosan is dissolved in acid to obtain a chitosan solution whose mass fraction is 2wt%-5wt%;

(3) mixing the polylactic acid solution obtained in step (1) and the chitosan solution obtained in step (2), then adding Yunnan Baiyao and silver salt to the mixed solution, stirring evenly under dark conditions to obtain an electrospinning solution;

(4) Electrospinning the electrospinning solution to obtain a medical antibacterial nano dressing.

Further, in step (1), the polylactic acid is stirred in an organic solvent for 2-4 hours to completely dissolve it.

Further, in step (1), the organic solvent includes a main solvent and an auxiliary solvent, the main solvent is chloroform or dichloromethane, and the auxiliary solvent is N,N-dimethylformamide or ethanol.

Further, when the auxiliary solvent is N,N-dimethylformamide, the mass ratio of the main solvent to N,N-dimethylformamide is 5:1-9:1; when the auxiliary solvent is ethanol, the main solvent The mass ratio of solvent to ethanol is 1:1-3:1.

Further, when the auxiliary solvent is N,N-dimethylformamide, the mass ratio of the main solvent to N,N-dimethylformamide is 9:1, 8:1, 7:1, 6:1 or 5 :1. When the auxiliary solvent is ethanol, the mass ratio of the main solvent to ethanol is 8:1, 7:1 or 6:1.

Preferably, by mass ratio, chloroform: ethanol = 1:1; dichloromethane: alcohol = 1:1; chloroform: N,N-dimethylformamide = 9:1; dichloromethane: N , N-dimethylformamide = 9:1.

Further, in step (2), the acid is formic acid or acetic acid.

Further, in step (2), stir the chitosan in acid for 4-6 hours to dissolve it completely.

Further, in step (3), the mass ratio of the polylactic acid solution to the chitosan solution is 1-2:1-3.

Further, in step (3), the mass ratio of the polylactic acid solution to the chitosan solution is 1:1, 2:1, 1:2 or 1:3. Preferably, the mass ratio of the polylactic acid solution to the chitosan solution is 1:1.

Further, in step (3), Yunnan Baiyao accounts for 8%-10% of the total mass of the mixed solution.

Further, in step (3), the silver salt is one or more of silver nitrate, silver chloride, silver bromide and silver iodide.

Further, in step (3), the silver salt accounts for 4%-6% of the mass of the mixed solution.

Further, in step (3), stir for 1-2 h under the condition of avoiding light.

Further, in step (4), electrospinning is carried out at 20-30° C. and 45%-65% relative humidity.

Further, the step (4) includes the following steps:

(S1) Pour the electrospinning solution into a syringe, connect a high-voltage power supply, cover the base layer on the receiving plate, and perform electrospinning at 10-20kV to obtain a layer of nanofiber film;

(S2) Attach a base layer on the nanofiber membrane obtained in step (S1), and carry out electrospinning at 10-20kV to form a second nanofiber membrane, after the second nanofiber membrane is formed Then cover a base layer to obtain a medical antibacterial nano dressing;

Wherein, the distance between the nozzle of the injector and the receiving plate is 10-20 cm, and the flow rate of the electrospinning solution is 0.4-1.0 ml/h.

Further, in the step (S1), the receiving plate is a metal plate. Cover the metal plate with three layers of gauze as a base layer.

Further, in step (S2), attach two layers of gauze as the base layer on the nanofiber membrane obtained in step (S1). After the second layer of nanofiber membrane is formed, it is covered with three layers of gauze.

By means of the above solution, the present invention has at least the following advantages:

Adopting the technical solution of the present invention, nanofibers with a diameter of about 60nm are prepared, and these nanofibers constitute an antibacterial nano dressing. The specific surface area of the nanofiber membrane is much larger than that of ordinary dressings. The larger the specific surface area, the stronger the adsorption performance, so it can absorb more drugs and release more drugs in the later stage; the dressing prepared by using chitosan and polylactic acid has excellent The mechanical properties and strength are good; Yunnan Baiyao is used to prepare the dressing, which has the functions of antibacterial, blood circulation, stasis, swelling and pain relief; silver ions, which are close to the antibacterial effect of antibiotics, are used as antibacterial substances, and combined with the advantages of Yunnan Baiyao and nanofibers Nano dressing, which can reach 97% antibacterial rate to Staphylococcus aureus, and can reach 99% antibacterial rate to Escherichia coli; the invention provides the most suitable raw material ratio and experimental conditions for preparing new medical dressings, and then uses electrostatic A medical antibacterial nano dressing is directly prepared by spinning technology, which has simple structure, convenient operation, simple control and short process flow.

The above description is only an overview of the technical solutions of the present invention. In order to understand the technical means of the present invention more clearly and implement them according to the contents of the description, the preferred embodiments of the present invention and accompanying drawings are described in detail below.

Description of drawings

Fig. 1 is the sectional structure schematic diagram of the medical antibacterial nano dressing prepared by the present invention;

Fig. 2 is the scanning electron micrograph of the overall appearance of nanofiber membrane in the medical antibacterial nano dressing prepared by the present invention;

Fig. 3 is the partial scanning electron micrograph of nanofiber film in the medical antibacterial nano dressing prepared by the present invention;

Fig. 4 is the schematic diagram that the medical antibacterial nano dressing prepared by the present invention scans silver under the desktop electron microscope energy spectrometer;

Fig. 5 is the elemental analysis result of the nanofibrous film in the medical antibacterial nano dressing of the present invention;

Fig. 6 is the infrared spectrogram of Yunnan Baiyao;

Fig. 7 is the infrared spectrogram of drug-loaded nanofiber membrane;

Explanation of reference numerals: 1 - medical gauze; 2 - drug-loaded nanofiber membrane.

detailed description

The specific implementation manners of the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

Example 1

Mix dichloromethane and N,N-dimethylformamide at a mass ratio of 9:1 in a brown ground-mouth bottle to obtain a mixed solvent. Then polylactic acid was dissolved in the above mixed solvent, stirred at a constant speed on a magnetic stirrer for 3 hours to completely dissolve, and a polylactic acid solution with a concentration of 8 wt% was prepared, and the solution was clear and transparent.

Chitosan was dissolved in glacial acetic acid in a beaker, and then stirred at a constant speed on a magnetic stirrer for 6 hours to completely dissolve to obtain a milky white chitosan solution with a concentration of 3 wt%.

Mix the above-mentioned polylactic acid solution and chitosan solution at a mass ratio of 1:1 in a brown ground-mouth bottle, then add 10% Yunnan Baiyao solution relative to the quality of the mixed solution, and add 10% of the solute quality relative to the mixed solution 5% silver nitrate. Wrap the brown ground bottle with aluminum foil to ensure that it is completely protected from light, and then stir it on a magnetic stirrer at a constant speed for 2 hours until the silver nitrate is completely dissolved to obtain a light yellow electrospinning solution.

The temperature of the experimental environment is controlled at 20°C-30°C, and the relative humidity is at 45%-65%. Pour the prepared electrospinning solution into a syringe with an inner diameter of 0.7mm and a capacity of 10ml and fix the syringe on the syringe pump. The plate is a metal plate, covered with three layers of gauze on the metal receiving plate as the base layer, and the distance between the receiving plate and the spinneret is adjusted to 15cm. After the experimental device is checked correctly, turn on the syringe pump and adjust the flow rate to 0.6ml/h. After the solution flows out slowly, turn on the high voltage power supply and adjust the voltage to 15kV to start the spinning experiment. After a layer of film is formed on the cotton fabric of the receiving plate, turn down the voltage device, attach two layers of gauze of equal size to the receiving plate, restart the voltage device, and after the second layer of film is formed, adjust the high-voltage power supply to zero and Cut off the power supply, then remove the cotton fabric on the metal receiving plate and cover three layers of gauze on the second layer of film to obtain a medical antibacterial nano dressing.

Example 2

Mix chloroform and absolute ethanol with a mass ratio of 8:1 in a brown ground-mouth bottle to obtain a mixed solvent. Then polylactic acid was dissolved in the above mixed solvent, stirred at a constant speed on a magnetic stirrer for 3 hours to completely dissolve, and a polylactic acid solution with a concentration of 10 wt% was prepared, and the solution was clear and transparent.

Chitosan was dissolved in glacial acetic acid in a beaker, and then stirred at a constant speed on a magnetic stirrer for 6 hours to completely dissolve to obtain a milky white chitosan solution with a concentration of 3 wt%.

Mix the above-mentioned polylactic acid solution and chitosan solution at a mass ratio of 1:1 in a brown ground-mouth bottle, then add 10% Yunnan Baiyao solution relative to the quality of the mixed solution, and add 10% of the solute quality relative to the mixed solution 6% silver chloride. Wrap the brown ground-mouth bottle with aluminum foil to ensure that it is completely protected from light, and then stir it on a magnetic stirrer at a constant speed for 2 hours until the silver chloride is completely dissolved to obtain a light yellow electrospinning solution.

The temperature of the experimental environment is controlled at 20°C-30°C, and the relative humidity is at 45%-65%. Pour the prepared electrospinning solution into a syringe with an inner diameter of 0.7mm and a capacity of 10ml and fix the syringe on the syringe pump. The plate is a metal plate, covered with three layers of gauze as the base layer on the metal receiving plate, and the distance between the receiving plate and the spinneret is adjusted to 13cm. After the experimental device is checked correctly, turn on the syringe pump and adjust the flow rate to 0.8ml/h. After the solution flows out slowly, turn on the high voltage power supply and adjust the voltage to 20kV to start the spinning experiment. After a layer of film is formed on the cotton fabric of the receiving plate, turn down the voltage device, attach two layers of gauze of equal size to the receiving plate, restart the voltage device, and after the second layer of film is formed, adjust the high-voltage power supply to zero and Cut off the power supply, then remove the cotton fabric on the metal receiving plate and cover three layers of gauze on the second layer of film to obtain a medical antibacterial nano dressing.

Example 3

Mix dichloromethane and N,N-dimethylformamide at a mass ratio of 5:1 in a brown ground-mouth bottle to obtain a mixed solvent. Then polylactic acid was dissolved in the above mixed solvent, stirred at a constant speed on a magnetic stirrer for 3 hours to completely dissolve, and a polylactic acid solution with a concentration of 8 wt% was prepared, and the solution was clear and transparent.

Chitosan was dissolved in glacial acetic acid in a beaker, and then stirred at a constant speed on a magnetic stirrer for 6 hours to completely dissolve to obtain a milky white chitosan solution with a concentration of 3 wt%.

Mix the above polylactic acid solution and chitosan solution in a brown ground-mouth bottle at a mass ratio of 2:1, then add 10% Yunnan Baiyao solution relative to the mass of the mixed solution, and add 10% of the solute mass relative to the mixed solution 6% silver iodide. Wrap the brown ground bottle with aluminum foil to ensure that it is completely protected from light, and then stir it on a magnetic stirrer at a constant speed for 2 hours until the silver iodide is completely dissolved to obtain a light yellow electrospinning solution.

The temperature of the experimental environment is controlled at 20°C-30°C, and the relative humidity is at 45%-65%. Pour the prepared electrospinning solution into a syringe with an inner diameter of 0.7mm and a capacity of 10ml and fix the syringe on the syringe pump. The plate is a metal plate, covered with three layers of gauze on the metal receiving plate as the base layer, and the distance between the receiving plate and the spinneret is adjusted to 15cm. After the experimental device is checked correctly, turn on the syringe pump and adjust the flow rate to 1.0ml/h. After the solution flows out slowly, turn on the high voltage power supply and adjust the voltage to 20kV to start the spinning experiment. After a layer of film is formed on the cotton fabric of the receiving plate, turn down the voltage device, attach two layers of gauze of equal size to the receiving plate, restart the voltage device, and after the second layer of film is formed, adjust the high-voltage power supply to zero and Cut off the power supply, then remove the cotton fabric on the metal receiving plate and cover three layers of gauze on the second layer of film to obtain a medical antibacterial nano dressing.

Example 4

Mix chloroform and ethanol with a mass ratio of 7:1 in a brown grinding bottle to obtain a mixed solvent. Then polylactic acid was dissolved in the above mixed solvent, stirred at a constant speed on a magnetic stirrer for 3 hours to completely dissolve, and a polylactic acid solution with a concentration of 9 wt% was prepared, and the solution was clear and transparent.

Chitosan was dissolved in glacial acetic acid in a beaker, and then stirred at a constant speed on a magnetic stirrer for 6 hours to completely dissolve to obtain a milky white chitosan solution with a concentration of 5 wt%.

Mix the above-mentioned polylactic acid solution and chitosan solution at a mass ratio of 1:1 in a brown ground-mouth bottle, then add 10% Yunnan Baiyao solution relative to the quality of the mixed solution, and add 10% of the solute quality relative to the mixed solution 6% silver iodide. Wrap the brown ground bottle with aluminum foil to keep it completely protected from light, then stir it on a magnetic stirrer at a constant speed for 2 h until the silver iodide is completely dissolved.

The temperature of the experimental environment is controlled at 20°C-30°C, and the relative humidity is at 45%-65%. Pour the prepared electrospinning solution into a syringe with an inner diameter of 0.7mm and a capacity of 10ml and fix the syringe on the syringe pump. The plate is a metal plate, covered with three layers of gauze on the metal receiving plate as the base layer, and the distance between the receiving plate and the spinneret is adjusted to 15cm. After the experimental device is checked correctly, turn on the syringe pump and adjust the flow rate to 0.6ml/h. After the solution flows out slowly, turn on the high voltage power supply and adjust the voltage to 15kV to start the spinning experiment. After a layer of film is formed on the cotton fabric of the receiving plate, turn down the voltage device, attach two layers of gauze of equal size to the receiving plate, restart the voltage device, and after the second layer of film is formed, adjust the high-voltage power supply to zero and Cut off the power supply, then remove the cotton fabric on the metal receiving plate and cover three layers of gauze on the second layer of film to obtain a medical antibacterial nano dressing.

Example 5

Mix chloroform and N,N-dimethylformamide with a mass ratio of 6:1 in a brown ground-mouth bottle to obtain a mixed solvent. Then polylactic acid was dissolved in the above mixed solvent, stirred at a constant speed on a magnetic stirrer for 3 hours to completely dissolve, and a polylactic acid solution with a concentration of 10 wt% was prepared, and the solution was clear and transparent.

Chitosan was dissolved in glacial acetic acid in a beaker, and then stirred at a constant speed on a magnetic stirrer for 6 hours to completely dissolve to obtain a milky white chitosan solution with a concentration of 3 wt%.

Mix the above-mentioned polylactic acid solution and chitosan solution at a mass ratio of 1:1 in a brown ground-mouth bottle, then add 8% Yunnan Baiyao solution relative to the quality of the mixed solution, and add 6% silver nitrate. Wrap the brown ground bottle with aluminum foil to ensure that it is completely protected from light, and then stir it on a magnetic stirrer at a constant speed for 2 hours until the silver nitrate is completely dissolved to obtain a light yellow electrospinning solution.

The temperature of the experimental environment is controlled at 20°C-30°C, and the relative humidity is at 45%-65%. Pour the prepared electrospinning solution into a syringe with an inner diameter of 0.7mm and a capacity of 10ml and fix the syringe on the syringe pump. The plate is a metal plate, covered with three layers of gauze on the metal receiving plate as the base layer, and the distance between the receiving plate and the spinneret is adjusted to 15cm. After the experimental device is checked correctly, turn on the syringe pump and adjust the flow rate to 0.4ml/h. After the solution flows out slowly, turn on the high voltage power supply and adjust the voltage to 20kV to start the spinning experiment. After a layer of film is formed on the cotton fabric of the receiving plate, turn down the voltage device, attach two layers of gauze of equal size to the receiving plate, restart the voltage device, and after the second layer of film is formed, adjust the high-voltage power supply to zero and Cut off the power supply, then remove the cotton fabric on the metal receiving plate and cover three layers of gauze on the second layer of film to obtain a medical antibacterial nano dressing.

Example 6

Mix chloroform and ethanol with a mass ratio of 8:1 in a brown ground bottle to obtain a mixed solvent. Then polylactic acid was dissolved in the above mixed solvent, stirred at a constant speed on a magnetic stirrer for 3 hours to completely dissolve, and a polylactic acid solution with a concentration of 8 wt% was prepared, and the solution was clear and transparent.

Chitosan was dissolved in glacial acetic acid in a beaker, and then stirred at a constant speed on a magnetic stirrer for 6 hours to completely dissolve to obtain a milky white chitosan solution with a concentration of 3 wt%.

Mix the above-mentioned polylactic acid solution and chitosan solution at a mass ratio of 1:1 in a brown ground-mouth bottle, then add 12% Yunnan Baiyao solution relative to the quality of the mixed solution to the solution, and add 5% silver bromide. Wrap the brown ground-mouth bottle with aluminum foil to ensure that it is completely protected from light, and then stir it on a magnetic stirrer at a constant speed for 2 hours until the silver bromide is completely dissolved.

The temperature of the experimental environment is controlled at 20°C-30°C, and the relative humidity is at 45%-65%. Pour the prepared electrospinning solution into a syringe with an inner diameter of 0.7mm and a capacity of 10ml and fix the syringe on the syringe pump. The plate is a metal plate, covered with three layers of gauze as the base layer on the metal receiving plate, and the distance between the receiving plate and the spinneret is adjusted to 13cm. After the experimental device is checked correctly, turn on the syringe pump and adjust the flow rate to 0.8ml/h. After the solution flows out slowly, turn on the high voltage power supply and adjust the voltage to 20kV to start the spinning experiment. After a layer of film is formed on the cotton fabric of the receiving plate, turn down the voltage device, attach two layers of gauze of equal size to the receiving plate, restart the voltage device, and after the second layer of film is formed, adjust the high-voltage power supply to zero and Cut off the power supply, then remove the cotton fabric on the metal receiving plate and cover three layers of gauze on the second layer of film to obtain a medical antibacterial nano dressing.

Example 7

Mix dichloromethane and N,N-dimethylformamide with a mass ratio of 7:1 in a brown ground-mouth bottle to obtain a mixed solvent. Then polylactic acid was dissolved in the above mixed solvent, stirred at a constant speed on a magnetic stirrer for 3 hours to completely dissolve, and a polylactic acid solution with a concentration of 9 wt% was prepared, and the solution was clear and transparent.

Chitosan was dissolved in glacial acetic acid in a beaker, and then stirred at a constant speed on a magnetic stirrer for 6 hours to completely dissolve to obtain a milky white chitosan solution with a concentration of 3 wt%.

Mix the above-mentioned polylactic acid solution and chitosan solution at a mass ratio of 1:1 in a brown ground-mouth bottle, then add 10% Yunnan Baiyao solution relative to the quality of the mixed solution, and add 10% of the solute quality relative to the mixed solution 5% silver nitrate. Wrap the brown ground bottle with aluminum foil to ensure that it is completely protected from light, and then stir it on a magnetic stirrer at a constant speed for 2 hours until the silver nitrate is completely dissolved to obtain a light yellow electrospinning solution.

The temperature of the experimental environment is controlled at 20°C-30°C, and the relative humidity is at 45%-65%. Pour the prepared electrospinning solution into a syringe with an inner diameter of 0.7mm and a capacity of 10ml and fix the syringe on the syringe pump. The plate is a metal plate, covered with three layers of gauze on the metal receiving plate as the base layer, and the distance between the receiving plate and the spinneret is adjusted to 20cm. After the experimental device is checked correctly, turn on the syringe pump and adjust the flow rate to 0.6ml/h. After the solution flows out slowly, turn on the high voltage power supply and adjust the voltage to 15kV to start the spinning experiment. After a layer of film is formed on the cotton fabric of the receiving plate, turn down the voltage device, attach two layers of gauze of equal size to the receiving plate, restart the voltage device, and after the second layer of film is formed, adjust the high-voltage power supply to zero and Cut off the power supply, then remove the cotton fabric on the metal receiving plate and cover three layers of gauze on the second layer of film to obtain a medical antibacterial nano dressing.

Example 8

Mix dichloromethane and ethanol with a mass ratio of 5:1 in a brown grinding bottle to obtain a mixed solvent. Then polylactic acid was dissolved in the above mixed solvent, stirred at a constant speed on a magnetic stirrer for 3 hours to completely dissolve, and a polylactic acid solution with a concentration of 9 wt% was prepared, and the solution was clear and transparent.

Chitosan was dissolved in glacial acetic acid in a beaker, and then stirred at a constant speed on a magnetic stirrer for 6 hours to completely dissolve to obtain a milky white chitosan solution with a concentration of 5 wt%.

Mix the above-mentioned polylactic acid solution and chitosan solution at a mass ratio of 1:1 in a brown ground-mouth bottle, then add 10% Yunnan Baiyao solution relative to the quality of the mixed solution, and add 10% of the solute quality relative to the mixed solution 5% silver chloride. Wrap the brown ground-mouth bottle with aluminum foil to ensure that it is completely protected from light, and then stir it on a magnetic stirrer at a constant speed for 2 hours until the silver chloride is completely dissolved to obtain a light yellow electrospinning solution.

The temperature of the experimental environment is controlled at 20°C-30°C, and the relative humidity is at 45%-65%. Pour the prepared electrospinning solution into a syringe with an inner diameter of 0.7mm and a capacity of 10ml and fix the syringe on the syringe pump. The plate is a metal plate, covered with three layers of gauze as the base layer on the metal receiving plate, and the distance between the receiving plate and the spinneret is adjusted to 13cm. After the experimental device is checked correctly, turn on the syringe pump and adjust the flow rate to 0.6ml/h. After the solution flows out slowly, turn on the high voltage power supply and adjust the voltage to 15kV to start the spinning experiment. After a layer of film is formed on the cotton fabric of the receiving plate, turn down the voltage device, attach two layers of gauze of equal size to the receiving plate, restart the voltage device, and after the second layer of film is formed, adjust the high-voltage power supply to zero and Cut off the power supply, then remove the cotton fabric on the metal receiving plate and cover three layers of gauze on the second layer of film to obtain a medical antibacterial nano dressing.

Fig. 2-3 is the scanning electron micrograph of the nanofiber film in the medical antibacterial nano dressing prepared by the present invention, can see the nanofiber that is fibrous form from the figure, and the diameter of the nanofiber prepared by the present invention is about 60nm, these nanofibers An antibacterial nano dressing is formed, and the dressing made of nanofibers aggregated into a film has a better drug release effect. Fig. 4 is a schematic diagram of the medical antibacterial nano dressing prepared by the present invention scanning silver under a desktop electron microscope energy spectrometer. The luminescent part in the figure is silver, indicating that silver is loaded into the dressing of the present invention, so that the antibacterial effect of the dressing is enhanced. Fig. 5 is the elemental analysis result of the nanofibrous membrane in the medical antibacterial nano dressing of the present invention, and the peak of silver can be seen from the figure. Figure 6 and Figure 7 are the infrared spectrograms of Yunnan Baiyao and the drug-loaded nanofiber membrane of the present invention respectively. It can be seen from the figure that the characteristic peaks of Yunnan Baiyao at 1747, 1087, and 1185 are all obvious on the drug-loaded nanofiber membrane. Peak. It is proved that Yunnan Baiyao exists in the drug-loaded nanofiber membrane.

The above is only a preferred embodiment of the present invention, and is not intended to limit the present invention. It should be pointed out that for those of ordinary skill in the art, some improvements can also be made without departing from the technical principle of the present invention. and modifications, these improvements and modifications should also be considered as the protection scope of the present invention.

Claims (10)

1. a preparation method of medical antibacterial nanometer dressing, is characterized in that, comprises the following steps: (1) Dissolving polylactic acid in an organic solvent to obtain a polylactic acid solution with a concentration of 6wt%-10wt%; (2) chitosan is dissolved in acid to obtain a chitosan solution whose mass fraction is 2wt%-5wt%; (3) Mix the polylactic acid solution obtained in step (1) with the chitosan solution obtained in step (2), then add Yunnan Baiyao and silver salt to the mixed solution, stir evenly under dark conditions to obtain static electricity spinning solution; (4) Electrospinning the electrospinning solution to obtain the medical antibacterial nano dressing. 2. the preparation method of medical antibacterial nano dressing according to claim 1 is characterized in that: in step (1), described organic solvent comprises main solvent and auxiliary solvent, and described main solvent is chloroform or dichloromethane methane, and the auxiliary solvent is N,N-dimethylformamide or ethanol. 3. the preparation method of medical antibacterial nano dressing according to claim 3 is characterized in that: the mass ratio of described main solvent and N,N-dimethylformamide is 5:1-9:1, and main solvent and The mass ratio of ethanol is 6:1-8:1. 4. The preparation method of medical antibacterial nano dressing according to claim 1, characterized in that: in step (2), the acid is formic acid or acetic acid. 5. the preparation method of medical antibacterial nanometer dressing according to claim 1 is characterized in that: in step (3), the mass ratio of described polylactic acid solution and chitosan solution is 1-2:1-3. 6. The preparation method of medical antibacterial nano dressing according to claim 1, characterized in that: in step (3), the Yunnan Baiyao accounts for 8%-10% of the total mass of the mixed solution. 7. the preparation method of medical antibacterial nano dressing according to claim 1 is characterized in that: in step (3), described silver salt is one or in silver nitrate, silver chloride, silver bromide and silver iodide Several kinds. 8. The preparation method of medical antibacterial nano dressing according to claim 1 or 7, characterized in that: in step (3), the silver salt accounts for 4%-6% of the mass of the mixed solution. 9. The preparation method of medical antibacterial nano dressing according to claim 1, characterized in that: in step (4), electrospinning is carried out at 20-30° C. and 45%-65% relative humidity. 10. the preparation method of medical antibacterial nano dressing according to claim 1, is characterized in that, described step (4) comprises the following steps: (S1) Pour the electrospinning solution into a syringe, connect a high-voltage power supply, cover the base layer on the receiving plate, and perform electrospinning at 10-20kV to obtain a layer of nanofiber film; (S2) Attach a base layer on the nanofiber membrane obtained in step (S1), and perform electrospinning at 10-20kV to form a second nanofiber membrane, and wait for the second nanofiber membrane After molding, cover a base layer to obtain the medical antibacterial nano dressing; Wherein, the distance between the nozzle of the injector and the receiving plate is 10-20 cm, and the flow rate of the electrospinning solution is 0.4-1.0 ml/h.