CN116407675A

CN116407675A - Antibacterial gel and preparation method and application thereof

Info

Publication number: CN116407675A
Application number: CN202310434549.0A
Authority: CN
Inventors: 陈�峰; 刘晓浩; 曹文涛
Original assignee: Shanghai Tenth Peoples Hospital
Current assignee: Shanghai Tenth Peoples Hospital
Priority date: 2023-04-21
Filing date: 2023-04-21
Publication date: 2023-07-11

Abstract

The invention discloses an antibacterial gel and a preparation method and application thereof, and is characterized by comprising the following raw materials in percentage by mass: 1-5% of chitosan, 0.1-0.5% of collagen, 5-15% of glycerol, 2-8% of polyvinyl alcohol and the balance of water. The preparation method comprises the following steps: adding collagen into glycerol water solution, adding oxalic acid, regulating pH to neutrality, adding polyvinyl alcohol and water soluble chitosan, stirring, and heating in water bath to obtain antibacterial gel. The invention also discloses application of the antibacterial gel in preparation of hydrogel dressing. The antibacterial gel and ultrathin transparent dressing combination has the characteristics of good ventilation and bacteria isolation performance, good biocompatibility, biodegradability and the like, has good light transmittance, can observe the state of a wound in real time, and is comfortable to wear without foreign body sensation.

Description

Antibacterial gel and preparation method and application thereof

Technical Field

The invention belongs to the technical field of biomedical materials, and particularly relates to an antibacterial gel and a preparation method and application thereof.

Background

The broad sense of wound surface refers to skin damage or defect caused by mechanical, physical, chemical or biological factors, and can be classified into acute wound and chronic wound according to the healing time of the wound surface. Acute wounds are those that form suddenly and heal faster, including superficial extradermal wounds, acute radiation injury wounds, and the like. Chronic wounds are injuries to skin tissue caused by various causes and the like, and have no tendency to heal after more than one month of treatment, and mainly include venous ulcers, arterial ulcers and the like. Wound healing is a complex dynamic process that includes hemostasis, inflammation, angiogenesis, epithelialization, granulation tissue formation, extracellular matrix deposition, and tissue remodeling.

Wound dressings play an important role in wound healing as temporary skin substitutes. Traditional dressing such as gauze, cotton pad and bandage have the functions of stopping bleeding, absorbing wound exudates, protecting the wound surface from bacterial infection, but do not have the active antibacterial and anti-inflammatory functions, and can cause leakage and sticky scab, and even obstruct the wound healing process. With the intensive research on wound healing, more requirements are also put on the function of wound dressing. The ideal wound dressing should firstly be able to provide a moist healing environment for the wound, have good breathability and mechanical protection, at the same time absorb wound exudates, protect the wound from contamination and bacterial infection, reduce necrosis of the wound surface, and stimulate growth of growth factors, and furthermore should have good biocompatibility, biodegradability, and be easy to remove and replace painlessly.

Bacterial cellulose is a natural high molecular polymer secreted by microorganisms such as Acetobacter, bacillus, agrobacterium, rhizobium and the like, and specifically comprises a nano high molecular material formed by polymerizing glucose molecules with beta-1, 4 glycosidic bonds. Bacterial cellulose has a three-dimensional porous network structure and possesses many excellent characteristics such as high mechanical strength, high crystallinity, high polymerization degree, high water retention and hydrophilicity, flexibility, and good biocompatibility, and it has been widely used in biomedical fields such as regenerative medicine, tissue engineering, wound care, and the like. However, how to obtain a film dressing with high light transmittance, water permeability and air permeability by using bacterial cellulose as a substrate is still a problem in the current related research and technical field, and bacterial cellulose in the prior art often cannot adhere well to skin.

Therefore, how to provide a method for improving the fit between bacterial cellulose and skin is a technical problem that needs to be solved by those skilled in the art.

Disclosure of Invention

In order to solve the technical problems, the invention provides an antibacterial gel and a preparation method and application thereof.

In order to achieve the above purpose, the present invention provides the following technical solutions:

an antibacterial gel comprises the following raw materials in percentage by mass: 1-5% of chitosan, 0.1-0.5% of collagen, 5-15% of glycerol, 2-8% of polyvinyl alcohol and the balance of water.

The beneficial effects are that: the hydrogel is a water-soluble hydrophilic polymer material, has a three-dimensional network structure, has high water content, can enhance biocompatibility by adding collagen, can keep wound surface moist by adding glycerol, can effectively resist bacteria and can be timely degraded, so as to avoid secondary damage caused by dressing replacement. In addition, the antibacterial gel provided by the invention has a transparent structure, can observe wounds in time, and is convenient for wound nursing.

Preferably, the material comprises the following raw materials in percentage by mass: 2-4% of chitosan, 0.2-0.4% of collagen, 7-13% of glycerol, 3-7% of polyvinyl alcohol and the balance of water.

Preferably, the material comprises the following raw materials in percentage by mass: 2.5 to 3.5 percent of chitosan, 0.25 to 0.35 percent of collagen, 9 to 11 percent of glycerol, 4 to 6 percent of polyvinyl alcohol and the balance of water.

A method for preparing an antibacterial gel, comprising the following steps:

adding collagen into glycerol water solution, adding oxalic acid until collagen can be uniformly dissolved, regulating pH to be neutral, adding polyvinyl alcohol and water-soluble chitosan, stirring, and heating in water bath to obtain antibacterial gel.

Preferably, the oxalic acid concentration is 0.1mol/L.

Preferably, the pH is adjusted by using ammonia water with a concentration of 2 mol/L.

Preferably, the water bath heating temperature is 70 ℃ and the time is 1 hour.

Preferably, the stirring rate is 60rpm.

Use of an antibacterial gel in the preparation of a hydrogel dressing.

Preferably, the hydrogel dressing comprises a laminate of the antimicrobial gel and an ultra-thin transparent dressing;

the ultrathin transparent dressing is a bacterial cellulose dry film with the thickness of 5-20 mu m.

More preferably, the preparation method of the ultrathin transparent dressing comprises the following steps of:

(1) Preparation of wet bacterial cellulose film: dynamically culturing acetobacter xylinum strains in a liquid culture medium, and then inoculating the acetobacter xylinum strains into a sterilized culture box for static culture to obtain a wet bacterial cellulose film;

(2) Purification of wet ultrathin dressing: washing the wet bacterial cellulose film, immersing the wet bacterial cellulose film in an alkali solution, heating in a water bath, naturally cooling to room temperature, continuing washing until the wet bacterial cellulose film becomes transparent, and finally placing the wet bacterial cellulose film in an ultra-pure water system for cooling overnight to obtain the wet ultrathin dressing;

(3) Preparation of a dry ultrathin dressing: after the wet ultrathin dressing is wiped to dry, the upper surface and the lower surface are covered with non-woven fabrics and pressed under a heavy object, and finally the dry ultrathin transparent dressing is obtained after drying;

(4) Forming and sterilizing the ultrathin transparent dressing: cutting and molding the dry ultrathin transparent dressing, and then sterilizing to obtain the ultrathin transparent dressing.

Further, in the dynamic culture process in the step (1), the volume ratio of the acetobacter xylinum strain in the liquid culture medium is (0.1-2): 100;

the dynamic culture temperature is 30 ℃, and the rotating speed is 100-200rpm;

the dynamic culture ending time is that the detection OD value is equal to 0.1-2.

Further, in the static culture process in the step (1), the volume ratio of the acetobacter xylinum strain to the liquid culture medium is 1: (1-20);

the static culture temperature is 30 ℃ and the time is 24-72 hours;

the thickness of the wet bacterial cellulose film is 200-600 mu m.

Further, in the step (2), the alkali solution is a NaOH solution, and the concentration of the NaOH solution is 0.05-0.5mol/L;

the heating temperature in the water bath is 95 ℃ and the time is 20-120 minutes.

Further, the drying temperature in the step (3) is 20-35 ℃ and the time is 6-18 hours.

Further, the sterilization in step (4) comprises gamma radiation or ethylene oxide sterilization.

The invention discloses an antibacterial gel and a preparation method and application thereof, wherein the antibacterial gel comprises chitosan, collagen, glycerol, polyvinyl alcohol and pure water, and after the antibacterial gel is combined with an ultrathin transparent dressing, the ultrathin transparent dressing can realize better fitting and adhesion on human skin under the auxiliary action of the antibacterial gel, and can be maintained for 8 hours without influencing normal work and life. In addition, the antibacterial gel and ultrathin transparent dressing combination has the characteristics of good ventilation and bacteria isolation performance, good biocompatibility, biodegradability and the like, has good light transmittance, can observe the state of a wound in real time, and is comfortable to wear without foreign body sensation.

Drawings

The accompanying drawings, which are included to provide a further understanding of the application, illustrate and explain the application and are not to be construed as limiting the application. In the drawings:

FIG. 1 is a scanning electron microscope image and a physical image of the antibacterial gel physical image obtained in the embodiment 1 of the invention and the ultrathin transparent dressing obtained;

wherein a is a physical image of the antibacterial gel, b is a scanning electron microscope image of the ultrathin transparent dressing, and c is a physical image of the ultrathin transparent dressing;

FIG. 2 is the thickness of the ultra-thin transparent dressing obtained in examples 1-3;

FIG. 3 is a graph showing the transmittance at 550nm of the antimicrobial gel and ultra-thin transparent dressing compositions obtained in examples 1-3;

FIG. 4 is a graph showing the results of the Water Vapor Transmission Rate (WVTR) of the ultra-thin transparent dressing obtained in examples 1-3;

FIG. 5 is a graph showing the results of the sterilization test of the ultra-thin transparent dressing obtained in examples 1-3;

FIG. 6 is a zone of inhibition experiment of the antimicrobial gel and ultra-thin transparent dressing composition obtained in examples 1-3;

FIG. 7 is a co-culture antimicrobial experiment of the antimicrobial gel and ultra-thin transparent dressing composition obtained in examples 1-3;

FIG. 8 is a graph showing the mechanical properties of the antimicrobial gel and ultra-thin transparent dressing compositions obtained in examples 1-3;

wherein a is a tensile strength test, b is a Young's modulus test;

FIG. 9 is a graph showing the results of biocompatibility measurements of the antimicrobial gel and ultra-thin transparent dressing compositions obtained in examples 1-3;

FIG. 10 is a graph showing the degradation results of the antimicrobial gel and ultra-thin transparent dressing composition obtained in example 2;

FIG. 11 is a graph showing the results of animal experiments on the antimicrobial gel and ultra-thin transparent dressing composition obtained in example 2;

FIG. 12 is a graph showing the results of the test for the fit of the antibacterial gel and the ultra-thin transparent dressing composition to human skin, which is obtained in example 2.

Detailed Description

The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

In order that the above-recited objects, features and advantages of the present invention will become more readily apparent, a more particular description of the invention will be rendered by reference to the appended drawings and appended detailed description.

Example 1

A method for preparing an antibacterial gel, comprising the following steps:

firstly, adding 5mL of glycerol into 95mL of pure water to prepare a glycerol aqueous solution, then adding 0.11g of collagen into the glycerol aqueous solution, dropwise adding 0.1mol/L of oxalic acid in the stirring process until the collagen is dissolved to form a uniform collagen solution, then adjusting the pH of the solution to 7.0 by using 2mol/L ammonia water, finally adding 2.1g of polyvinyl alcohol and 1.1g of water-soluble chitosan, and heating and stirring in a water bath at 70 ℃ for dissolving for 1 hour until uniform transparent gel is formed, thus obtaining the antibacterial gel.

The preparation method of the ultrathin transparent dressing comprises the following steps:

(1) Preparation of wet bacterial cellulose

Inoculating the acetobacter xylinum strain and the culture medium into a liquid culture medium according to the volume ratio of 0.1:100, then placing the liquid culture medium on a constant temperature shaking table for dynamic culture at 30 ℃ and 100rpm until the OD value of the bacterial liquid is measured to be 0.1, and then inoculating the bacterial liquid into a conventional culture box sterilized under high temperature and high pressure according to the volume ratio of 1:1 of the acetobacter xylinum bacterial liquid to the liquid culture medium, so that the volume of a final culture system is 30mL, blowing off uniformly, and then placing the culture box into a 30 ℃ incubator for continuous culture for 24 hours to obtain the wet bacterial cellulose film with the thickness of 200-600 mu m.

(2) Purification of wet ultrathin dressing

Repeatedly cleaning the wet bacterial cellulose film after the culture with tap water for 10 times, soaking the wet bacterial cellulose film in 0.05M NaOH solution, heating the wet bacterial cellulose film in water bath at 95 ℃ for 20 minutes, cooling the wet bacterial cellulose film at room temperature, continuously flushing the wet bacterial cellulose film with tap water until the wet bacterial cellulose film becomes transparent, putting the wet bacterial cellulose film into a ultrapure water system, putting the wet bacterial cellulose film into a 4-DEG C refrigerator for 12 hours for stirring and soaking, and fishing out the wet bacterial cellulose film the next day to obtain the wet ultrathin dressing.

(3) Preparation of dry ultrathin dressing

Draining water from the wet ultrathin dressing by using a strainer, clamping the wet ultrathin dressing in the middle by using non-woven fabrics to form a sandwich structure, and sucking the surface water as much as possible by using paper towels, and repeating the sucking for a plurality of times until no water is sucked out from the surfaces of the paper towels. And (3) applying a pressure of 2.5KPa to the non-woven sandwich structure with the bacterial cellulose film sandwiched therebetween, and finally drying at 25 ℃ for 6 hours to obtain the dry ultrathin dressing.

(4) Shaping and sterilizing transparent dressing with ultrathin structure

Cutting and molding the dry ultrathin dressing, and then carrying out gamma ray irradiation or ethylene oxide sterilization treatment to obtain the ultrathin transparent dressing.

The scanning electron microscope image and the optical image of the antibacterial gel super optical image and the obtained ultrathin transparent dressing are shown in the figure 1, and the antibacterial gel has certain light transmittance, and the thickness of the ultrathin transparent dressing is only about 7 microns.

The hydrogel dressing is an antibacterial gel and ultrathin transparent dressing composition, and the preparation method comprises the following steps:

laminating the antibacterial gel and the ultrathin transparent dressing to obtain the antibacterial gel and ultrathin transparent dressing composition.

Example 2

A method for preparing an antibacterial gel, comprising the following steps:

firstly, 10mL of glycerin is directly added into 90mL of pure water to prepare glycerin aqueous solution, then 0.3g of collagen is added into the glycerin aqueous solution, 0.1mol/L of oxalic acid is added dropwise in the stirring process until the collagen is dissolved to form uniform collagen solution, and then the pH value of the solution is regulated to 7.0 by using 2mol/L of ammonia water. Finally, 5g of polyvinyl alcohol and 3g of water-soluble chitosan are added, and the mixture is heated, stirred and dissolved in a water bath at 70 ℃ for 1 hour until uniform transparent gel is formed, thus obtaining the antibacterial gel.

(1) Preparation of wet bacterial cellulose

Inoculating acetobacter xylinum strain and a culture medium into a liquid culture medium according to a volume ratio of 1:100, then placing the liquid culture medium on a constant temperature shaking table to perform dynamic culture at 30 ℃ and 150rpm until the OD value of a bacterial liquid is measured to be 1, inoculating the bacterial liquid into a conventional culture box sterilized at high temperature and high pressure according to a volume ratio of 1:5 of the acetobacter xylinum bacterial liquid to the liquid culture medium, enabling the volume of a final culture system to be 30mL, blowing off uniformly, and placing the culture box into a culture box at 30 ℃ to perform continuous culture for 48 hours to obtain a wet bacterial cellulose film with the thickness of 200-600 mu m.

(2) Purification of wet ultrathin dressing

Repeatedly cleaning the wet bacterial cellulose film after the culture with tap water for 10 times, soaking the wet bacterial cellulose film in 0.2M NaOH solution, heating the wet bacterial cellulose film in water bath at 95 ℃ for 60 minutes, cooling the wet bacterial cellulose film at room temperature, continuously flushing the wet bacterial cellulose film with tap water until the wet bacterial cellulose film becomes transparent, putting the wet bacterial cellulose film into a ultrapure water system, placing the wet bacterial cellulose film in a 4-DEG C refrigerator for 12 hours, stirring and soaking the wet bacterial cellulose film, and fishing out the wet bacterial cellulose film the next day to obtain the wet bacterial cellulose film.

(3) Preparation of dry ultrathin dressing

Draining water from the wet ultrathin dressing by using a strainer, clamping the wet ultrathin dressing in the middle by using non-woven fabrics to form a sandwich structure, and sucking the surface water as much as possible by using paper towels, and repeating the sucking for a plurality of times until no water is sucked out from the surfaces of the paper towels. And (3) applying a pressure of 2.5KPa to the non-woven sandwich structure with the bacterial cellulose film sandwiched therebetween, and finally drying at 30 ℃ for 12 hours to obtain the dry ultrathin dressing.

(4) Shaping and sterilizing transparent dressing with ultrathin structure

Example 3

A method for preparing an antibacterial gel, comprising the following steps:

13mL of glycerin is directly added into 83mL of pure water to prepare glycerin aqueous solution, then 0.5g of collagen is added into the glycerin aqueous solution, 0.1mol/L of oxalic acid is added dropwise in the stirring process until the collagen is dissolved to form uniform collagen solution, then the pH value of the solution is regulated to 7.0 by using 2mol/L of ammonia water, finally 8g of polyvinyl alcohol and 5g of water-soluble chitosan are added, and the mixture is heated, stirred and dissolved in a water bath at 70 ℃ for 1 hour until uniform transparent gel is formed, thus obtaining the antibacterial gel.

(1) Preparation of wet bacterial cellulose

Inoculating acetobacter xylinum strain and a culture medium into a liquid culture medium according to a volume ratio of 1:10, then placing the liquid culture medium on a constant temperature shaking table to perform dynamic culture at 30 ℃ and 200rpm until the OD value of a bacterial liquid is measured to be 2, inoculating the bacterial liquid into a conventional culture box sterilized at high temperature and high pressure according to a volume ratio of 1:20 of the acetobacter xylinum bacterial liquid to the liquid culture medium, enabling the volume of a final culture system to be 30mL, blowing off uniformly, and placing the culture box into a culture box at 30 ℃ to perform continuous culture for 72 hours to obtain a wet bacterial cellulose film with the thickness of 200-600 mu m.

(2) Purification of wet ultrathin dressing

Repeatedly cleaning the wet bacterial cellulose film after the culture with tap water for 10 times, soaking the wet bacterial cellulose film in 0.5M NaOH solution, heating the wet bacterial cellulose film in water bath at 95 ℃ for 20 minutes, cooling the wet bacterial cellulose film at room temperature, continuously flushing the wet bacterial cellulose film with tap water until the wet bacterial cellulose film becomes transparent, putting the wet bacterial cellulose film into a ultrapure water system, placing the wet bacterial cellulose film in a 4-DEG C refrigerator for 12 hours, stirring and soaking the wet bacterial cellulose film, and fishing out the wet bacterial cellulose film the next day to obtain the wet bacterial cellulose film.

(3) Preparation of dry ultrathin dressing

(4) Shaping and sterilizing transparent dressing with ultrathin structure

The technical effects are as follows:

1. thickness measurement of ultra-thin transparent dressing

After stacking 2 pairs of dry bacterial cellulose films, thickness measurements were made and the resulting values divided by 4, 3 samples were selected for each set of tests, reducing measurement errors.

The results are shown in fig. 2, and it can be seen that the thickness thereof is decreasing as the process conditions are changed.

2. Measurement of light transmittance of antimicrobial gel and ultra-thin transparent dressing compositions

The dry bacterial cellulose film was cut to be slightly narrower than the width of the glass cuvette, then the antibacterial gel was smeared on the inside of the glass cuvette, then the dry bacterial cellulose film was stuck on the inside, and then the light transmittance was measured at 550nm with an ultraviolet-visible spectrophotometer (Shimadzu UV-1900 i).

As a result, as shown in fig. 3, it can be seen that since the result of fig. 2 illustrates that the thickness thereof is decreasing with the change of the processing conditions, the result of fig. 3 illustrates that the light transmittance thereof is increasing with the change of the processing conditions, but the change is not very remarkable.

3. Measurement of Water Vapor Transmission Rate (WVTR) of ultra-thin transparent dressing

According to the national pharmaceutical industry standard, part 2 of the contact wound dressing test method: breathable film dressing Water vapor Transmission Rate (YY/T0471.2-2004) breathability was tested as follows: the dry bacterial cellulose film (thickness is the same as that of the water resistance test) is fixed on the bottle mouth area (S, unit m ² ) Is 10cm ² Is filled with water and weighs W1 (g). At constant temperature of (37+ -0.5) deg.C and relative humidity<After being placed in a space of 20% for 24 hours, W2 was weighed again, and the water vapor transmission rate was calculated according to the following formula in g/m ² /day。

WVTR＝(W1-W2)/S

As a result, as shown in fig. 4, it can be seen that the water vapor permeability increases with the change of the treatment conditions.

4. Measurement of the bacterial isolation Property of ultra-thin transparent dressing

Adopting gram-negative bacteria such as Escherichia coli (E.coli) and gram-positive bacteria such as Staphylococcus aureus (S.aureus) as research objects, respectively irradiating positive and negative directions of a dry bacterial cellulose film with ultraviolet for 30 minutes, pasting on the surface of LB solid medium, and then dripping 5 mu L of the film with the concentration of 10 ⁸ CFU/mL bacterial liquid. After 24 hours of culture in a 30 ℃ incubator, photographing to see whether bacterial liquid on the surface of the film grows, removing the film, photographing again to see whether bacterial colony grows on the surface of the LB solid medium.

As a result, as shown in FIG. 5, it can be seen that a dry bacterial cellulose film was stuck to the surface of LB solid medium, and then 5. Mu.L of 10-concentration solution was dropped ⁸ CFU/mL bacterial liquid. After 24 hours of incubation, the film was removed and no colony on the surface of the solid medium covered with the film was observed with naked eyes, indicating that the dressing had a function of blocking bacteria.

5. Determination of antimicrobial gel and ultra-thin transparent dressing composition antimicrobial properties

Firstly, when the sterilized LB solid medium is cooled to 55 ℃, a certain amount of bacterial liquid is mixed to prepare a liquid containing 10 ⁶ CFU/mL LB plates for E.coli and Staphylococcus aureus. The antibacterial gel and the ultrathin transparent dressing composition are respectively irradiated with ultraviolet for 30 minutes, punched into 8mm size by a puncher, then respectively stuck on the surface of a cooled LB solid culture medium, and the size of a bacteriostasis zone is observed after 24 hours.

Firstly, respectively irradiating the antibacterial gel and the ultrathin transparent dressing composition for 30 minutes, then cutting into films with the diameter of 4cm, and then putting 20mL of films containing 10 ⁶ Co-culturing in physiological saline of CFU/mL Escherichia coli and Staphylococcus aureus at 37deg.C for 12 hr, and diluting for 10 ⁴ Plating was performed after doubling, and then the colony count was observed.

The results are shown in fig. 6, and it can be seen that transparent inhibition zones are generated around the antibacterial gel and the ultra-thin transparent dressing composition, indicating antibacterial properties. The results of FIG. 7 show that the colony count on the plate surface varies from group to group, and further illustrate the antibacterial property.

6. Measurement of mechanical Properties of antimicrobial gel and ultra-thin transparent dressing compositions

The antibacterial gel and ultrathin transparent dressing composition were cut into strips of 4cm×1cm, the stretching speed was set at 5mm/min, and the instrument used for the test was Shanghai Hengyu HY-940FS.

The results are shown in fig. 8, and it can be seen that the dressing has better tensile strength and Young's modulus, and can meet the mechanical properties required by the wound dressing.

7. Evaluation of biocompatibility of antibacterial gel and ultrathin transparent dressing composition

In the biocompatibility evaluation, the cell activity is determined by adopting skin fibroblast NIH3T3, firstly, the antibacterial gel and the ultrathin transparent dressing composition are cut and sterilized by respectively irradiating ultraviolet for 30 minutes in the front and back directions, then the sterilized antibacterial gel and the ultrathin transparent dressing composition are co-cultured with cells, and the cell activity is detected by using an MTT method.

The procedure of the hemolysis test is as follows, the fresh blood of the carotid artery of the rat is collected by a vacuum anticoagulation blood collection tube, the erythrocytes are collected by centrifugation at 1500rpm for 15 minutes, and then resuspended to 4% w/v erythrocyte suspension by physiological saline. In 96-well plates, 100. Mu.L of material extract was added to each well of the experimental group, and the extract was prepared using physiological Saline (Saline), or material co-culture was added thereto. 100. Mu.L of physiological saline and deionized water were added to the negative control group and the positive control group, respectively. mu.L of the above 4% w/v red blood cell suspension was added to each well, and after incubation at 37℃for 4 hours, photographs were taken. Centrifugation at 1500rpm was then carried out for 15 minutes, and 100. Mu.L of the supernatant was taken into a new 96-well plate and absorbance was measured at 540nm using an enzyme-labeled instrument (SpectraMax iD5, molecular Devices). The haemolysis rate was calculated according to the following formula:

wherein Abss, absp and andAbsn represent absorbance at 540nm in the experimental group, the positive control group and the negative control group, respectively.

Live & read Viability/CytotoxicityAssay Kit forAnimal Cells (Kjeldahl Bio, KGAF 001) was used for cell death staining, and specific procedures are described in the specification.

As a result, as shown in FIG. 9, it was found that the cell activity of the portion A was detected, and that the cell activity was maintained at 85% or more after 24 hours and 48 hours of co-culture. The part B is the detection result of the hemolysis of the material, the hemolysis rate of the dressing is about 1%, and the hemolysis rate is within 5% so as to meet the requirements of the wound dressing. Part C is the result of cell death staining of the material, also indicating no cytotoxicity.

8. Antibacterial gel and ultra-thin transparent dressing composition degradability test

The antibacterial gel and the ultrathin transparent dressing composition are cut into the size of 1cm multiplied by 1cm, then the antibacterial gel and the ultrathin transparent dressing composition are buried in the empty space around the shrubs, a pit is dug at a position 5cm away from the ground, the cut film is buried in the pit as an experimental group, and the common plastic film is cut into the same size as a control group and buried in the ground together, and the film is photographed every 4 days.

As a result, as shown in fig. 10, it can be seen that the cellulose was completely degraded at day 12, and the control plastic film was still completely present.

9. Animal experiments with antimicrobial gel and ultra-thin transparent dressing compositions

SD female rats 10 weeks old were selected as subjects, and full skin defect linear wounds were made on their backs, then antibacterial gel was applied and ultra-thin transparent dressings were applied.

As a result, as shown in fig. 11, it can be seen that the dressing had good transparency and conformable properties.

10. Human skin fit test of antimicrobial gel and ultra-thin transparent dressing composition

Skin fit experiments are carried out on the inner side of the arm, after antibacterial gel is uniformly coated, ultrathin transparent dressing is attached, normal study and work are carried out, and then photographing and observation are carried out at different times respectively.

As a result, as shown in fig. 12, it can be seen that the composition still adheres well to the skin surface over 8 hours of daily wear, indicating that the dressing has good wearable properties.

The foregoing is merely a preferred embodiment of the present application, but the scope of the present application is not limited thereto, and any changes or substitutions easily conceivable by those skilled in the art within the technical scope of the present application should be covered in the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. The antibacterial gel is characterized by comprising the following raw materials in percentage by mass: 1-5% of chitosan, 0.1-0.5% of collagen, 5-15% of glycerol, 2-8% of polyvinyl alcohol and the balance of water.

2. An antibacterial gel according to claim 1, comprising the following raw materials in mass fraction: 2-4% of chitosan, 0.2-0.4% of collagen, 7-13% of glycerol, 3-7% of polyvinyl alcohol and the balance of water.

3. An antibacterial gel according to claim 1, comprising the following raw materials in mass fraction: 2.5 to 3.5 percent of chitosan, 0.25 to 0.35 percent of collagen, 9 to 11 percent of glycerol, 4 to 6 percent of polyvinyl alcohol and the balance of water.

4. A method of preparing an antimicrobial gel according to any one of claims 1 to 3, comprising the steps of:

adding collagen into glycerol water solution, adding oxalic acid, regulating pH to neutrality, adding polyvinyl alcohol and water soluble chitosan, stirring, and heating in water bath to obtain antibacterial gel.

5. The method for preparing an antibacterial gel according to claim 4, wherein the oxalic acid concentration is 0.1mol/L.

6. The method according to claim 4, wherein the pH is adjusted by using ammonia water having a concentration of 2 mol/L.

7. The method of claim 4, wherein the water bath heating temperature is 70 ℃ for 1 hour.

8. The method for preparing an antibacterial gel according to claim 4, wherein the stirring rate is 60rpm.

9. Use of an antimicrobial gel according to any one of claims 1 to 3 for the preparation of a hydrogel dressing.

10. The use according to claim 9, wherein the hydrogel dressing comprises a laminate of the antimicrobial gel and an ultra-thin transparent dressing;