Composite bacterial cellulose dressing as well as preparation method and application thereof

Abstract

The invention discloses a composite bacterial cellulose dressing as well as a preparation method and application thereof, and belongs to the technical field of medical dressings. The preparation method of the composite bacterial cellulose dressing comprises the following steps: S1, treating a bacterial cellulose membrane with an alkaline solution and an acidic solution in sequence, and then cleaning until the pH value is nearly neutral to obtain a purified bacterial cellulose membrane; s2, placing the purified bacterial cellulose membrane between two layers of support materials, and dehydrating to obtain a primary dressing; s3, the primary dressing is soaked in a solution containing cationic polysaccharide, sterilization is conducted, and the composite bacterial cellulose dressing is prepared. The composite bacterial cellulose dressing can effectively maintain the physical and chemical stability of cationic polysaccharide, can effectively promote the healing of wounds, especially acute wounds and chronic refractory wounds, and shortens the wound healing time.

Description

Technical Field

[0001] This invention relates to the field of medical dressing technology, and in particular to a composite bacterial cellulose dressing, its preparation method, and its application. Background Technology

[0002] Dressings are widely used medical materials in clinical practice, primarily for covering wounds or other damaged skin tissue areas to achieve multiple functions such as wound protection, exudate absorption, and promoting healing. In recent years, natural polymer materials have gradually become one of the preferred raw materials for preparing novel medical dressings due to their excellent biocompatibility, biodegradability, and physicochemical properties similar to traditional dressings. Bacterial cellulose is a natural polysaccharide material produced by microorganisms through fermentation. It has a unique nanofiber network structure, exhibiting good mechanical properties, high water retention, excellent air permeability, and biocompatibility, and is widely regarded as an ideal wound dressing matrix material. Although bacterial cellulose has many advantages in terms of structure and performance, it lacks effective antibacterial activity and has limited inhibitory and disruptive effects on bacterial biofilms, making it difficult to meet the dual requirements of antibacterial and healing-promoting properties for chronic, non-healing wounds.

[0003] Currently, some studies have attempted to functionalize bacterial cellulose dressings. For example, patent CN115487340B discloses a bacterial cellulose dressing loaded with reactive oxygen species, which achieves a certain antibacterial effect by introducing hydrogen peroxide solution and antibacterial components. However, the stability of its antibacterial component—reactive oxygen species—is poor, making it difficult to maintain its effect over a long period. Patent CN116173282B discloses a moist bacterial cellulose dressing and its preparation method, which can improve the moisturizing properties of bacterial cellulose dressings, but its ability to inhibit bacteria or break down biofilms remains relatively limited.

[0004] Therefore, providing a bacterial cellulose dressing with antibacterial, anti-biofilm, and wound-healing properties is an urgent problem to be solved in this field. Summary of the Invention

[0005] To address the aforementioned problems in existing technologies, this invention provides a composite bacterial cellulose dressing, its preparation method, and its application. The composite bacterial cellulose dressing of this invention exhibits excellent antibacterial biofilm properties and wound healing-promoting effects.

[0006] The technical solution of the present invention is as follows: The first aspect of this invention protects a method for preparing a composite bacterial cellulose dressing, comprising the following steps: S1. The bacterial cellulose membrane is treated with alkaline solution and acidic solution in sequence, and then washed until the pH is close to neutral to obtain a purified bacterial cellulose membrane. S2. Place the purified bacterial cellulose membrane between two layers of support material and dehydrate it to obtain a primary dressing. S3. The primary dressing is impregnated in a solution containing cationic polysaccharides and sterilized to obtain a composite bacterial cellulose dressing.

[0007] Preferably, in step S1, the bacterial cellulose membrane is prepared by static culture fermentation of Acetobacter xylose. The static culture fermentation includes: activating Acetobacter xylose to prepare a seed culture, inoculating the seed culture into the fermentation medium at an inoculation rate of 1-10% (v / v), and statically culturing at 28-30°C for 7-14 days.

[0008] Preferably, in step S1, the alkaline solution includes at least one of sodium hydroxide solution, potassium hydroxide solution, and calcium hydroxide solution; And / or, treatment with an alkaline solution includes immersing the bacterial cellulose membrane in a 0.5-5 wt% alkaline solution at 80-90°C for 6-18 h; And / or, the acidic solution includes at least one of hydrochloric acid solution and sulfuric acid solution; And / or, treatment with an acidic solution includes immersing the bacterial cellulose membrane in a 0.5-5 wt% acidic solution at 20-25°C for 2-12 h; And / or, wash again until the pH is 6.5~7.5.

[0009] Preferably, in step S2, the supporting material includes at least one of PET film, non-woven fabric, and gauze; And / or, the thickness of the bacterial cellulose membrane in the primary dressing is 0.1~4 mm.

[0010] Preferably, in step S3, the molecular weight of the cationic polysaccharide is 40-120 kDa; the cationic polysaccharide includes at least one of polyaminoethyl glucose, ethylenediamine-modified dextran, diethylenetriamine-modified dextran, and N,N-dimethylethylenediamine-modified dextran. And / or, the content of cationic polysaccharides in the solution is 0.01~0.5wt%.

[0011] Preferably, in step S3, the solution comprises 0.5-10 wt% humectant, 0.05-0.5 wt% chelating agent, and 0.01-0.5 wt% phosphate; The humectant includes at least one of glycerol and propylene glycol; The chelating agent includes at least one of disodium ethylenediaminetetraacetate and sodium citrate; The phosphate includes at least one of disodium hydrogen phosphate and sodium dihydrogen phosphate; And / or, the pH of the composite bacterial cellulose dressing is 6.5 to 7.5.

[0012] Preferably, in step S3, the sterilization includes at least one of gamma-ray irradiation sterilization and electron beam irradiation sterilization, and the irradiation sterilization dose is 20~40 kGy.

[0013] A second aspect of this invention protects a composite bacterial cellulose dressing, which is prepared by the above-described preparation method.

[0014] Preferably, the loading of cationic polysaccharides in the composite bacterial cellulose dressing is 0.1~5 mg / cm³. 2 The liquid holding capacity of the composite bacterial cellulose dressing is ≥95%.

[0015] A third aspect of this invention protects the use of a composite bacterial cellulose dressing in the preparation of products for protecting wounds and / or promoting wound healing, said composite bacterial cellulose dressing comprising the composite bacterial cellulose dressing described in the second aspect, and / or the composite bacterial cellulose dressing prepared by the preparation method described in the first aspect.

[0016] The beneficial technical effects of this invention are as follows: (1) The present invention loads cationic polysaccharides with good antibacterial biofilm ability onto bacterial cellulose membranes to prepare a composite bacterial cellulose dressing. This dressing can effectively maintain the physicochemical stability and activity of cationic polysaccharides. At the same time, it fully combines the good biocompatibility and safety of bacterial cellulose with the broad-spectrum antibacterial biofilm ability of cationic polysaccharides. This dressing can effectively promote the healing of wounds, especially acute wounds and chronic difficult-to-heal wounds, and shorten the wound healing time.

[0017] (2) The preparation process of the composite bacterial cellulose dressing of the present invention is simple, green and environmentally friendly, and can be industrialized and has good application prospects. Attached Figure Description

[0018] Figure 1 The image shows the infrared spectrum of the ethylenediamine-modified dextran in Example 1.

[0019] Figure 2 The result diagram is shown in Test Example 1 of the present invention.

[0020] Figure 3 The result diagram is shown in Test Example 2 of the present invention.

[0021] Figure 4 The result diagram is shown for test example 3 of the present invention.

[0022] Figure 5 The result diagram is shown for test example 4 of the present invention. Detailed Implementation

[0023] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0024] A method for preparing a composite bacterial cellulose dressing includes the following steps: S1. The bacterial cellulose membrane is treated with alkaline solution and acidic solution in sequence, and then washed until the pH is close to neutral to obtain a purified bacterial cellulose membrane. S2. Place the purified bacterial cellulose membrane between two layers of support material and dehydrate it to obtain a primary dressing. S3. The primary dressing is impregnated in a solution containing cationic polysaccharides and sterilized to obtain a composite bacterial cellulose dressing.

[0025] The bacterial cellulose membrane is prepared by static culture fermentation of Acetobacter xylose. The static culture fermentation includes: activating Acetobacter xylose to prepare a seed culture, inoculating the seed culture into the fermentation medium at an inoculation rate of 1-10% (v / v), and statically culturing at 28-30°C for 7-14 days.

[0026] The preparation of the seed culture includes the following steps: Take a small amount of Acetobacter xylinum statice, and under aseptic conditions, scrape it with an inoculation loop and streak it on an HS (Hestrin-Schramm Medium) agar plate; place the inoculated plate in a 28℃ constant temperature incubator and incubate statically for 5 days to obtain an activated bacterial film; under aseptic conditions, scrape a small amount of the bacterial film with an inoculation loop and inoculate it into liquid HS medium, and incubate at 28℃ and 180 rpm for 24 hours to obtain a turbid and homogeneous liquid seed culture.

[0027] In some implementations, in step S2, the dehydration can be carried out by applying external pressure.

[0028] In some embodiments, in step S2, after dehydration, the dressing can be cut into different shapes as needed and placed into a packaging container to obtain a primary dressing.

[0029] In some embodiments, step S3, in which the primary dressing is impregnated in a solution containing cationic polysaccharides, specifically includes: placing the primary dressing into a packaging container, filling the packaging container with the solution containing cationic polysaccharides, and sealing it.

[0030] In some embodiments, in step S3, the loading of cationic polysaccharides in the composite bacterial cellulose dressing is 0.1~5 mg / cm³. 2 .

[0031] For chronic, refractory wounds, bacterial biofilms are one of the core factors hindering healing. Biofilms are formed by bacterial communities adhering to the wound surface, encapsulated in a self-produced polysaccharide matrix, forming a physical barrier that is difficult to remove with traditional antibiotics or other removal methods.

[0032] Cationic polysaccharides are novel medical biomaterials with broad-spectrum antibacterial biofilm activity and wound-healing properties, and they are not prone to drug resistance. The amino and hydroxyl groups in their molecular structure give them good water solubility and biocompatibility. However, chemically modified cationic polysaccharides are easily denatured during sterilization, leading to changes in their physicochemical properties and a significant decrease in their biological activity.

[0033] This invention provides a composite bacterial cellulose dressing prepared by loading cationic polysaccharides onto a bacterial cellulose membrane. This solves the problem that cationic polysaccharides are easily denatured under irradiation sterilization conditions. It can continuously keep the wound moist, has good antibacterial biofilm ability, can prevent and inhibit the formation of bacterial biofilm on the wound surface, promote wound healing, and shorten wound healing time.

[0034] The Acetobacter xylinum used in the following embodiments and comparative examples of the present invention were purchased from the U.S. Center for Type Culture Collection.

[0035] In the following embodiments and comparative examples of the present invention, the fermentation medium used for preparing bacterial cellulose membranes by static culture and fermentation of Acetobacter xylinum is as follows: HS medium is prepared as follows: each 1 L of medium contains 20 g of glucose, 5 g of peptone, 5 g of yeast extract, 2.7 g of disodium hydrogen phosphate, 1.15 g of citric acid, and distilled water to a final volume of 1 L. The pH is adjusted to 5-6 and then sterilized by moist heat at 121°C for 20 minutes.

[0036] The cationic polysaccharide of the present invention can be prepared by referring to the preparation method disclosed in the patent application number 201911235541.1.

[0037] The bacterial cellulose dressings used in the following test examples of the present invention were purchased from Zhende Medical Products Co., Ltd.

[0038] Example 1 A method for preparing a composite bacterial cellulose dressing includes the following steps: S1. After activating Acetobacter xylinum, prepare a seed culture. Inoculate the seed culture into the fermentation medium at an inoculation rate of 1% (v / v) and culture statically at 28°C for 10 days. The resulting bacterial cellulose membrane is treated with 2wt% NaOH solution at 80°C for 12 hours to remove bacteria and impurities. Then, it is treated with 2wt% hydrochloric acid at 25°C for 12 hours to neutralize the alkaline residue. Finally, it is washed multiple times with deionized water until the pH reaches neutral to obtain a purified bacterial cellulose membrane.

[0039] S2. The purified bacterial cellulose membrane is placed between two layers of non-woven fabric, subjected to water pressing, cut to 7 cm × 8 cm, and placed in a packaging container to obtain the primary dressing; the thickness of the bacterial cellulose membrane in the primary dressing is 2 mm.

[0040] S3. Prepare 30 mL of phosphate buffer (0.3 wt% disodium hydrogen phosphate, 0.2 wt% sodium dihydrogen phosphate, pH=7.0) containing 0.3 wt% cationic polysaccharide (ethylenediamine-modified dextran), 5 wt% glycerol, and 0.2 wt% disodium ethylenediaminetetraacetate. Fill the buffer into a packaging container, seal the container, and sterilize using 30 kGy gamma irradiation to obtain a composite bacterial cellulose dressing. The cationic polysaccharide loading in this composite bacterial cellulose dressing is 1.6 mg / cm³. 2 The liquid holding capacity of the composite bacterial cellulose dressing is ≥95%.

[0041] The ethylenediamine-modified dextran was prepared by the following method: 1) Weigh 0.5 g of dextran with a molecular weight of 70,000 Daltons (purchased from Sigma-Aldrich (Shanghai) Trading Co., Ltd., item number 31390), and dissolve it completely in 25 mL of dimethyl sulfoxide to obtain a mixed solution; 2) Weigh 1 gram of N'N-carbonyldiimidazole and add it to the mixed solution. React at room temperature for 2 hours. 3) Add 2 grams of ethylenediamine dropwise and continue the reaction at 25°C for 24 hours; 4) After the reaction is complete, add 5 times the volume of anhydrous ethanol to the obtained solution, stir thoroughly, centrifuge the precipitate at 12,000 rpm for 10 minutes, wash the precipitate three times with anhydrous ethanol, and then vacuum dry for 48 h to obtain the product. Dry and store for later use.

[0042] The prepared ethylenediamine-modified dextran was characterized by infrared spectroscopy: 200 mg of potassium bromide and 2 mg of ethylenediamine-modified dextran sample were finely ground in an agate mortar, and the grinding process was completed under infrared lamp heating throughout; the sample powder was placed into a mold and pressurized to 20 MPa, and held for 2 minutes. The pressure was slowly reduced to 0, the pressed sample was removed, pressed into a tablet, and tested.

[0043] The results are as follows Figure 1 As shown, 1711cm -1 The peak at 1544 cm⁻¹ represents the stretching vibration peak of the carbonyl carbon-oxygen double bond. -1 The peak at 1022 cm⁻¹ represents the bending vibration peak of the nitrogen-hydrogen bond in primary amino groups. -1 The peaks at the specified locations represent the characteristic absorption peaks of pyridine glucose, and the appearance of these peaks proves that the synthesis of ethylenediamine-modified dextran was successful.

[0044] Example 2 A method for preparing a composite bacterial cellulose dressing is basically the same as that in Example 1, except that it is sterilized by 20 kGy γ-ray irradiation. The rest is the same as in Example 1.

[0045] Example 3 A method for preparing a composite bacterial cellulose dressing is basically the same as that in Example 1, except that it is sterilized by 40 kGy γ-ray irradiation. The rest is the same as in Example 1.

[0046] Example 4 A method for preparing a composite bacterial cellulose dressing is basically the same as in Example 1, except that: in this example, in step S2, the dressing is cut to 5 cm × 6 cm; and in step S3, the loading of cationic polysaccharides in the composite bacterial cellulose dressing is 3 mg / cm³. 2 Everything else is the same as in Example 1.

[0047] Example 5 A method for preparing a composite bacterial cellulose dressing is basically the same as in Example 1, except that: in this example, in step S2, the dressing is cut to a size of 5 cm × 4 cm; and in step S3, the loading of cationic polysaccharides in the composite bacterial cellulose dressing is 4.5 mg / cm³. 2 Everything else is the same as in Example 1.

[0048] Comparative Example 1 A method for preparing a composite bacterial cellulose dressing is basically the same as that in Example 1, except that it is sterilized by 0 kGy γ-ray irradiation, and the rest is the same as in Example 1.

[0049] Test example: Test Example 1: The therapeutic effect of composite bacterial cellulose dressing on a Pseudomonas aeruginosa-infected wound model (1) Establishment of a mouse back trauma model: BALB / c female mice were weighed and recorded, and randomly divided into five groups of 10 mice each. The mice were anesthetized with sodium pentobarbital intraperitoneal anesthesia, their backs were shaved and disinfected, and a circular piece of skin with a diameter of 0.5 cm was cut off from the thicker part of the skin in the center of the mouse back to serve as a mouse back trauma model.

[0050] (2) Pseudomonas aeruginosa infection in mice: Mice in each group were infected with 10 μL of Pseudomonas aeruginosa at the wound site. 8 Apply a dose of CFU / piece evenly to Pseudomonas aeruginosa and bacterial solution. After 72 hours, the bacteria can form a complete bacterial biofilm, resulting in a chronic, non-healing wound.

[0051] (3) Drug administration: The patients were grouped as follows: Blank control group: 100 μL of normal saline was applied to the wound area before drug administration; Control group 1: Prontosan was applied to the wound area during administration. ® Gel wound dressing (purchased from B. Braun Switzerland AG) 100 μL; Control group 2: 100 μL of phosphate solution containing 0.3 wt% cationic polysaccharide (ethylenediamine-modified dextran) was applied to the wound area at the time of administration; Control group 3: Commercially available bacterial cellulose dressings were applied to the wound area during drug administration; Experimental group: When administering the medication, the wound area was covered with the composite bacterial cellulose dressing prepared in Example 1 of this invention.

[0052] After treatment, the mice were placed in a warm, bright, and comfortable environment until they awoke. Wound healing was monitored daily, and the time to complete wound healing was recorded. The average wound healing time and standard deviation (SD) were calculated. Results are as follows: Figure 2 As shown, according to Figure 2 It can be seen that the mice treated with the composite bacterial cellulose dressing of Example 1 of the present invention had the shortest wound healing time, indicating that the composite bacterial cellulose dressing of the present invention can accelerate the wound healing process. This is because the composite bacterial cellulose dressing of the present invention can quickly inhibit the proliferation and spread of bacteria and the formation of bacterial biofilms, effectively inhibit the production of endotoxins and exotoxins by bacteria, and slow down the progression of the disease.

[0053] Test Example 2: Stability Test of Cationic Polysaccharides in Composite Bacterial Cellulose Dressing (1) Experimental groups: Control group 1: The cationic polysaccharide raw material (ethylenediamine-modified dextran) in Example 1 was dissolved in ultrapure water to obtain a cationic polysaccharide solution with a concentration of 0.3 wt%.

[0054] Control group 2: Cationic polysaccharide solution prepared for control group 1 of this test case, which was sterilized by 30 kGy γ-ray irradiation.

[0055] Control group 3: Phosphate buffer containing 0.3 wt% cationic polysaccharide (ethylenediamine-modified dextran), 5 wt% glycerol, and 0.2 wt% disodium ethylenediaminetetraacetate (0.3 wt% disodium hydrogen phosphate, 0.2 wt% sodium dihydrogen phosphate, pH=7.0) sterilized by 30 kGy γ-ray irradiation.

[0056] Control group 4: Composite bacterial cellulose dressing prepared in comparative example 1.

[0057] Experimental Group 1: Composite bacterial cellulose dressing prepared in Example 1.

[0058] (2) Sample preparation: Cationic polysaccharides were recovered from each experimental group and control group using an ultrafiltration tube with a molecular weight cutoff of 3000 Daltons, and washed five times with ultrapure water. The resulting solutions were then freeze-dried.

[0059] (3) Nitrogen content determination: The nitrogen content of the sample after step (2) was determined by the Kjeldahl method, and the results are as follows: Figure 3 As shown.

[0060] according to Figure 3 It can be seen that the nitrogen content of control group 2 is significantly lower than that of control group 1, and the nitrogen content of control group 3 is significantly lower than that of control group 1. This indicates that when cationic polysaccharides are sterilized by γ-ray irradiation in aqueous solution or in the phosphate buffer solution containing moisturizer and chelating agent of the present invention, the nitrogen content of the polysaccharides decreases, that is, the structure of the cationic polysaccharides is destroyed. In experimental group 1 using the composite bacterial cellulose dressing of the present invention, the nitrogen content after γ-ray irradiation sterilization at the same dose as control groups 2 and 3 is not significantly different from that of control groups 1 and 4, that is, the structure of the cationic polysaccharides is not destroyed. This shows that the composite bacterial cellulose dressing of the present invention can still effectively maintain the physicochemical stability and activity of cationic polysaccharides after irradiation sterilization treatment.

[0061] Test Example 3: Effect of Radiation Dose on Composite Bacterial Cellulose (1) Experimental groups: Control group 1: The cationic polysaccharide raw material (ethylenediamine-modified dextran) from Example 1 was dissolved in ultrapure water to obtain a cationic polysaccharide solution with a concentration of 0.3 wt%.

[0062] Experimental Group 1: Composite bacterial cellulose dressing prepared in Example 1.

[0063] Experimental Group 2: Composite bacterial cellulose dressing prepared in Example 2.

[0064] Experimental Group 3: Composite bacterial cellulose dressing prepared in Example 3.

[0065] Experimental Group 4: Composite bacterial cellulose dressing prepared in Comparative Example 1.

[0066] (2) Sample preparation: The cationic polysaccharides in each experimental group and the control group were recovered using an ultrafiltration tube with a molecular weight cutoff of 3000 Daltons, and washed five times with ultrapure water. The resulting solutions were then freeze-dried.

[0067] (3) Nitrogen content determination: The nitrogen content of the sample after step (2) was determined by the Kjeldahl method, and the results are as follows: Figure 4 As shown.

[0068] according to Figure 4It can be seen that, compared with control group 1 and experimental group 4, the nitrogen content of cationic polysaccharides in experimental groups 1-3 changed slightly with the increase of radiation dose. The higher the radiation dose, the lower the corresponding nitrogen content. It can be inferred that when preparing composite bacterial cellulose dressings, excessive radiation dose will destroy the stability of cationic polysaccharides in composite bacterial cellulose dressings.

[0069] Test Example 4: Effect of cationic polysaccharide loading on composite bacterial cellulose (1) Experimental groups: Control group 1: The cationic polysaccharide raw material (ethylenediamine-modified dextran) from Example 1 was dissolved in ultrapure water to obtain a cationic polysaccharide solution with a concentration of 0.3 wt%.

[0070] Experimental Group 1: Composite bacterial cellulose dressing prepared in Example 1.

[0071] Experimental Group 2: Composite bacterial cellulose dressing prepared in Example 4.

[0072] Experimental Group 3: Composite bacterial cellulose dressing prepared in Example 5.

[0073] Experimental Group 4: Composite bacterial cellulose dressing prepared in Comparative Example 1.

[0074] (2) Sample preparation: The cationic polysaccharides in each experimental group and the control group were recovered using an ultrafiltration tube with a molecular weight cutoff of 3000 Daltons, and washed five times with ultrapure water. The resulting solutions were then freeze-dried.

[0075] (3) Nitrogen content determination: The nitrogen content of the sample after step (2) was determined by the Kjeldahl method, and the results are as follows: Figure 5 As shown.

[0076] according to Figure 5 It can be seen that, compared with control group 1 and experimental group 4, the nitrogen content of cationic polysaccharides in experimental groups 1-3 changed slightly with the increase of loading. The higher the loading, the lower the nitrogen content. However, the nitrogen content of experimental groups 1-3 was relatively high. It can also be inferred that if the loading is too high when preparing composite bacterial cellulose dressing, the composite bacterial cellulose dressing will have a poor ability to protect the stability of cationic polysaccharides.

[0077] In summary, the composite bacterial cellulose dressing prepared by this invention can maintain the physicochemical stability of the loaded cationic polysaccharides after irradiation sterilization treatment, effectively inhibiting the proliferation and spread of bacteria and the formation of bacterial biofilm, thereby promoting rapid wound healing.

[0078] The above description is merely a preferred embodiment of the present invention, and the present invention is not limited to the above embodiments. It is understood that other improvements and variations that are directly derived or conceived by those skilled in the art without departing from the spirit and concept of the present invention should be considered to be included within the protection scope of the present invention.

Claims

1. A method for preparing a composite bacterial cellulose dressing, characterized in that, Includes the following steps: S1. The bacterial cellulose membrane is treated with alkaline solution and acidic solution in sequence, and then washed until the pH is close to neutral to obtain a purified bacterial cellulose membrane. S2. Place the purified bacterial cellulose membrane between two layers of support material and dehydrate it to obtain a primary dressing. S3. The primary dressing is impregnated in a solution containing cationic polysaccharides and sterilized to obtain a composite bacterial cellulose dressing.

2. The preparation method according to claim 1, characterized in that, In step S1, the bacterial cellulose membrane is prepared by static culture fermentation of Acetobacter xylose. The static culture fermentation includes: activating Acetobacter xylose to prepare a seed culture, inoculating the seed culture into the fermentation medium at an inoculation rate of 1-10% (v / v), and statically culturing at 28-30°C for 7-14 days.

3. The preparation method according to claim 1, characterized in that, In step S1, the alkaline solution includes at least one of sodium hydroxide solution, potassium hydroxide solution, and calcium hydroxide solution; And / or, treatment with an alkaline solution includes immersing the bacterial cellulose membrane in a 0.5-5 wt% alkaline solution at 80-90°C for 6-18 h; And / or, the acidic solution includes at least one of hydrochloric acid solution and sulfuric acid solution; And / or, treatment with an acidic solution includes immersing the bacterial cellulose membrane in a 0.5-5 wt% acidic solution at 20-25°C for 2-12 h; And / or, wash again until the pH is 6.5~7.

5.

4. The preparation method according to claim 1, characterized in that, In step S2, the supporting material includes at least one of PET film, non-woven fabric, and gauze; And / or, the thickness of the bacterial cellulose membrane in the primary dressing is 0.1~4 mm.

5. The preparation method according to claim 1, characterized in that, In step S3, the molecular weight of the cationic polysaccharide is 40~120 kDa; the cationic polysaccharide includes at least one of polyaminoethyl glucose, ethylenediamine-modified dextran, diethylenetriamine-modified dextran, and N,N-dimethylethylenediamine-modified dextran. And / or, the content of cationic polysaccharides in the solution is 0.01~0.5wt%.

6. The preparation method according to claim 1, characterized in that, In step S3, the solution contains 0.5-10 wt% humectant, 0.05-0.5 wt% chelating agent, and 0.01-0.5 wt% phosphate. The humectant includes at least one of glycerol and propylene glycol; The chelating agent includes at least one of disodium ethylenediaminetetraacetate and sodium citrate; The phosphate includes at least one of disodium hydrogen phosphate and sodium dihydrogen phosphate; And / or, the pH of the composite bacterial cellulose dressing is 6.5 to 7.

5.

7. The preparation method according to claim 1, characterized in that, In step S3, the sterilization includes at least one of gamma-ray irradiation sterilization and electron beam irradiation sterilization, and the irradiation sterilization dose is 20~40 kGy.

8. A composite bacterial cellulose dressing, characterized in that, The composite bacterial cellulose dressing is prepared by the preparation method described in any one of claims 1 to 7.

9. The composite bacterial cellulose dressing according to claim 8, characterized in that, The loading of cationic polysaccharides in the composite bacterial cellulose dressing is 0.1~5 mg / cm³. 2 The liquid holding capacity of the composite bacterial cellulose dressing is ≥95%.

10. The use of a composite bacterial cellulose dressing in the preparation of products for protecting wounds and / or promoting wound healing, characterized in that, The composite bacterial cellulose dressing includes the composite bacterial cellulose dressing according to any one of claims 8 to 9, and / or the composite bacterial cellulose dressing prepared by the preparation method according to any one of claims 1 to 7.

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