AFGF-loaded bacterial cellulose suture line as well as preparation method and application thereof

Abstract

The invention relates to the technical field of biological materials, in particular to an aFGF-loaded bacterial cellulose suture line and a preparation method and application thereof.The preparation method comprises the steps that a bacterial cellulose membrane is provided; the bacterial cellulose membrane is cut into strip-shaped components, and then the strip-shaped components are woven into bacterial cellulose suture lines; and soaking the bacterial cellulose suture line in the aFGF solution, and airing to obtain the aFGF-loaded bacterial cellulose suture line. The preparation process is simple and easy to implement, and the prepared suture line is good in biocompatibility and good in wound healing promoting effect and also has an anti-adhesion effect.

Description

Technical Field

[0001] The invention relates to the technical field of biomaterials, and in particular to a bacterial cellulose suture thread loaded with aFGF, and a preparation method and application thereof. Background Art

[0002] Surgical sutures are a long-established and necessary suture medical device, and they play a key role in closing damaged blood vessels and organs and assisting in postoperative wound healing. Although some products, such as biomedical glues, adhesives, and nails, have been developed as alternatives to sutures, it is indisputable that surgical sutures still account for more than half of the global surgical device market due to their high stability, feasibility, and applicability. Surgical sutures are an ancient device that was originally used to assist in wound repair and has entered a new intelligent stage in recent decades. The choice of materials, fiber morphology, structure and construction of sutures, as well as suture structure modification, functionalization, and even intelligence are all research directions for sutures in modern times. The choice of materials is crucial to the manufacture of sutures, and it has a great impact on the performance of the sutures finally obtained. Compared with traditional non-degradable suture materials, absorbable suture materials exhibit some unique properties that enable them to degrade in vivo without the need for later resection, thereby protecting patients from secondary trauma. Although a variety of commercial sutures are available clinically, improving the biological performance of currently used sutures remains a huge challenge. Summary of the invention

[0003] The purpose of the present invention is to provide a bacterial cellulose suture loaded with aFGF and a preparation method and application thereof. The preparation process is simple and easy, the prepared suture has good biocompatibility, good wound healing effect, and anti-adhesion effect.

[0004] In order to achieve the above object, the technical solution adopted by the present invention is as follows: In a first aspect, the present invention provides a method for preparing aFGF-loaded bacterial cellulose suture, comprising: providing a bacterial cellulose membrane; cutting the bacterial cellulose membrane into strip-shaped components, and then weaving the strip-shaped components into bacterial cellulose sutures; The bacterial cellulose suture thread is immersed in the aFGF solution and then dried to obtain the bacterial cellulose suture thread loaded with aFGF.

[0005] Furthermore, the preparation of the bacterial cellulose membrane comprises the following steps: Step 1, preparing expansion medium and production medium; Step 2, picking up Acetobacter xylinum colonies and placing them in an amplification medium, shaking and culturing them to obtain Acetobacter xylinum amplification liquid; Step 3, inoculating the Acetobacter xylinum amplification solution into the production culture medium, adding anhydrous ethanol and stirring evenly, pouring into a culture dish, and placing the culture dish in a bacterial constant temperature incubator for static culture to obtain a bacterial cellulose original film; Step 4: Use distilled water to wash away the bacterial solution and residues on the original bacterial cellulose membrane, boil it in a sodium hydroxide solution, then wash it with distilled water for multiple times, and finally spread it on a plate to dry naturally to obtain a bacterial cellulose membrane.

[0006] Further, the amplification medium in step 1 comprises 3-7 g / L of glucose, 3-7 g / L of yeast powder, 3-7 g / L of polypeptone and 0.5-1.2 g / L of citric acid; And / or, the production medium in step 1 includes 20-40 g / L of glucose, 3-7 g / L of yeast powder, 3-7 g / L of polypeptone, 0.1-0.25 g / L of magnesium sulfate, 0.05-0.1 g / L of potassium dihydrogen phosphate and 0.5-1.2 g / L of citric acid.

[0007] Furthermore, the process parameters of the shaking culture in step 2 include: the rotation speed is set to 150~180r / min, the temperature is set to 28~30°C, and the shaking culture time is set to 36~48h.

[0008] Furthermore, in step 3, 40-80 mL of Acetobacter xylinum amplification solution and 3-8 mL of anhydrous ethanol are added to every 1 L of production culture medium, the temperature of the bacterial constant temperature incubator is set to 28-30° C., and the static culture time is set to 5-10 days.

[0009] Furthermore, the concentration of the aFGF solution is 1-100 μg / L, and the immersion time is set to 1-60 min.

[0010] Furthermore, the strip-shaped component has a width of 1-5 mm, a length of 15-25 cm, and a thickness of 0.8-1.5 mm.

[0011] Furthermore, the braiding pattern of the strip-shaped member is single helix, double helix or triple braid.

[0012] In a second aspect, the present invention provides a bacterial cellulose suture loaded with aFGF, which is prepared by the above-mentioned preparation method.

[0013] In a third aspect, the present invention provides a use of aFGF-loaded bacterial cellulose suture thread prepared by the above preparation method in medical dressings.

[0014] The present invention has the following unexpected beneficial effects: 1. The present invention uses bacterial cellulose as a substrate to weave bacterial cellulose sutures. Compared with traditional plant cellulose, although bacterial cellulose retains a similar skeleton at the molecular level, it eliminates redundant components such as lignin, hemicellulose and pectin, making its performance more excellent. The higher crystallinity gives it structural indestructibility, and the enhanced stability ensures the reliable performance of the material in various environments, while the excellent biocompatibility further broadens its application boundaries in the biomedical field. The high water holding capacity and good biodegradability of bacterial cellulose make it an environmentally friendly material that can be absorbed and degraded by the human body to a certain extent, and has no toxic side effects on the human body. Therefore, it is of great clinical value to prepare bacterial cellulose into surgical sutures. And in view of the excellent specific surface area and fiber pores of bacterial fibers, drugs, namely aFGF, can be loaded, and the healing quality of wounds can be further improved by combined use.

[0015] 2. The preparation process of the present invention does not generate waste gas or waste liquid, is environmentally friendly, and is simple and easy to operate with low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A flow chart of a method for preparing aFGF-loaded bacterial cellulose suture provided in an embodiment of the present invention is shown.

[0017] Figure 2 A flow chart of a method for preparing a bacterial cellulose membrane provided by an embodiment of the present invention is shown.

[0018] Figure 3 A flow chart showing the use of methylene blue to color aFGF-loaded bacterial cellulose sutures.

[0019] Figure 4 The surface morphology SEM image of the bacterial cellulose membrane prepared in the present invention is shown.

[0020] Figure 5 A statistical diagram of the in vitro degradation of the bacterial cellulose membrane prepared in the present invention is shown.

[0021] Figure 6 The surface morphology structure diagrams of bacterial cellulose suture, methylene blue-dyed bacterial cellulose suture and methylene blue-dyed double-helix bacterial cellulose suture loaded with aFGF are shown.

[0022] Figure 7 A statistical graph of the tensile strength of bacterial cellulose sutures after stretching is shown.

[0023] Figure 8 A statistical graph showing the elongation of bacterial cellulose sutures after stretching.

[0024] Fig. 9The figure shows the surface morphology of the broken end of the bacterial cellulose suture after stretching.

[0025] Fig.10 A graph showing the test results of the cell compatibility of bacterial cellulose sutures.

[0026] Fig.11 A graph showing the test results of the blood compatibility of bacterial cellulose sutures.

[0027] Fig.12 A graph showing the test results of the in vivo biological safety of bacterial cellulose sutures.

[0028] Fig.13 HE and Masson diagrams of bacterial cellulose sutures and commercial silk threads at different time points after subcutaneous embedding.

[0029] Fig.14 The figure shows the effect of bacterial cellulose sutures on rat wound skin suture.

[0030] Fig.15 A diagram showing the effect of bacterial cellulose sutures on rat tendon suture.

[0031] Fig.16 A diagram showing the effect of bacterial cellulose sutures on suturing gastric perforation in rats.

[0032] Fig.17 A diagram showing the effect of bacterial cellulose sutures on rat intestinal incision suture. DETAILED DESCRIPTION

[0033] The following will describe the embodiments of the present invention with reference to the accompanying drawings and preferred embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be understood that the preferred embodiments are only for illustrating the present invention, not for limiting the scope of protection of the present invention.

[0034] In one embodiment, see Figure 1 As shown, the present invention provides a method for preparing aFGF-loaded bacterial cellulose suture, comprising: Provided is a bacterial cellulose membrane; the bacterial cellulose membrane is a starting material for preparing sutures, and the membrane has excellent mechanical properties, biocompatibility and absorbability, and is very suitable for use in the medical field.

[0035] Cutting the bacterial cellulose membrane into strips is a step to convert the membrane material into a shape suitable for weaving into a thread. The cutting process requires precise control of the width and length of the strips to ensure the strength and applicability of the final suture. The strips are then woven into bacterial cellulose sutures. The weaving process can increase the strength and flexibility of the sutures, making them more suitable for suturing wounds.

[0036] The bacterial cellulose suture is soaked in the aFGF solution. This step is to make the aFGF evenly loaded on the suture. aFGF has the effect of promoting wound healing and cell regeneration, so the suture loaded with aFGF has significant advantages in medical applications.

[0037] The bacterial cellulose suture loaded with aFGF is obtained by air drying. The drying process needs to control appropriate temperature and humidity to ensure that aFGF can be stably attached to the suture while avoiding adverse effects on the mechanical properties of the suture. Exemplarily, the air drying method is natural room temperature air drying, baking or oven drying.

[0038] Among them, aFGF is the English abbreviation of acidic fibroblast growth factor.

[0039] The present invention uses bacterial cellulose as a substrate and weaves a bacterial cellulose suture. Compared with traditional plant cellulose, although bacterial cellulose retains a similar skeleton at the molecular level, it eliminates redundant components such as lignin, hemicellulose and pectin, making its performance more excellent, and the higher crystallinity gives it structural indestructibility, and the enhanced stability ensures the reliable performance of the material in various environments, and the excellent biocompatibility further broadens its application boundaries in the biomedical field. The high water holding capacity and good biodegradability of bacterial cellulose make it an environmentally friendly material that can be absorbed and degraded by the human body to a certain extent, and has no toxic side effects on the human body. Therefore, it is of great clinical value to prepare bacterial cellulose into surgical sutures. And in view of the excellent specific surface area and fiber pores of bacterial fiber, it can load drugs, namely aFGF, and further improve the healing quality of wounds by combined use.

[0040] The preparation process of the invention does not generate waste gas or waste liquid, is environmentally friendly, and is simple and easy to operate with low cost.

[0041] In a preferred embodiment, see Figure 2 As shown, the preparation of the bacterial cellulose membrane includes the following steps: Step 1: Prepare expansion medium and production medium. The expansion medium is used to initially expand the number of Acetobacter xylinum to prepare for its large-scale reproduction in the subsequent production medium. The production medium provides the nutrients required for the growth of Acetobacter xylinum to support its synthesis of bacterial cellulose.

[0042] Step 2: Pick up Acetobacter xylinum colonies in an amplification medium, and culture them by shaking. The shaking promotes the uniform distribution and reproduction of Acetobacter xylinum in the amplification medium to obtain Acetobacter xylinum amplification liquid.

[0043] Step 3: Inoculate the Acetobacter xylinum amplification solution into the production medium to start the synthesis process of bacterial cellulose. Add anhydrous ethanol and stir evenly, pour into a culture dish, and place the culture dish in a bacterial constant temperature incubator for static culture. Under suitable temperature and humidity conditions, let the Acetobacter xylinum grow statically on the production medium to synthesize the original bacterial cellulose film.

[0044] Step 4: Use distilled water to wash away the bacterial liquid and residues on the original bacterial cellulose membrane, that is, remove the excess bacteria and culture medium components on the bacterial cellulose membrane. Then boil it in sodium hydroxide solution to remove impurities on the bacterial cellulose membrane, such as proteins, polysaccharides, etc., and it also helps to improve the texture and performance of the membrane. Then use distilled water to wash several times to thoroughly remove sodium hydroxide and other possible residues. Finally, lay it flat on a plate and dry it naturally to dry and shape the bacterial cellulose membrane for subsequent cutting and weaving.

[0045] Furthermore, the amplification medium described in step 1 includes 3-7 g / L of glucose, 3-7 g / L of yeast powder, 3-7 g / L of polypeptone and 0.5-1.2 g / L of citric acid. Glucose, as a carbon source, provides energy for Acetobacter xylinum. Yeast powder provides a variety of amino acids, vitamins and trace elements to promote the growth of Acetobacter xylinum. Polypeptone provides a nitrogen source and essential amino acids to support the growth and reproduction of bacteria. Citric acid can be used to adjust the pH value of the culture medium and can also be used as a carbon source.

[0046] The production medium described in step one includes 20~40g / L glucose, 3~7g / L yeast powder, 3~7g / L polypeptone, 0.1~0.25g / L magnesium sulfate, 0.05~0.1g / L potassium dihydrogen phosphate and 0.5~1.2g / L citric acid. Higher glucose concentrations are beneficial to the synthesis of bacterial cellulose. The choice of concentration range may depend on the specific production conditions and target yield. Yeast powder also provides amino acids, vitamins and trace elements to support bacterial growth and cellulose synthesis. Polypeptone provides a nitrogen source, which is essential for the synthesis of bacterial cellulose. Magnesium sulfate, as an inorganic salt, plays an important role in the growth and metabolism of bacteria. Potassium dihydrogen phosphate provides phosphorus and also helps to adjust the pH value of the culture medium. Citric acid is also used to adjust the pH value and may serve as an additional carbon source.

[0047] Furthermore, the process parameters of the shaking culture in step 2 include: the rotation speed is set to 150-180 r / min. The appropriate rotation speed can promote oxygen exchange and uniform distribution of nutrients in the culture medium, which is beneficial to the growth and reproduction of Acetobacter xylinum.

[0048] The temperature is set at 28~30℃, which is suitable for the growth of Acetobacter xylinum and can maintain its high metabolic activity.

[0049] The shaking culture time is set to 36-48 hours, which is enough for Acetobacter xylinum to reach a certain order of magnitude in the amplification medium and prepare for subsequent inoculation and production.

[0050] Furthermore, in step 3, 40-80 mL of Acetobacter xylinum amplification solution and 3-8 mL of anhydrous ethanol are added to each 1 L of production culture medium. The amount of amplification solution added ensures that there is a sufficient number of bacteria to synthesize bacterial cellulose. The role of a specific content of anhydrous ethanol is to provide a carbon source to promote the growth and reproduction of bacteria. Bacteria use anhydrous ethanol for metabolism to generate energy, which is used for the synthesis and secretion of bacterial cellulose. In addition, anhydrous ethanol may also affect the osmotic pressure and pH value of the culture medium, thereby indirectly affecting the growth environment of bacteria, and further affecting the yield and quality of bacterial cellulose. The temperature of the bacterial constant temperature incubator is set to 28-30°C, which is conducive to maintaining the stable growth of bacteria and the synthesis of cellulose. The static culture time is set to 5-10 days. Long-term static culture allows Acetobacter xylinum to fully grow and synthesize a large amount of bacterial cellulose.

[0051] In a preferred embodiment, the concentration of the aFGF solution is 1-100 μg / L, which ensures that aFGF can be uniformly adsorbed on the bacterial cellulose membrane while avoiding the side effects that may be caused by too high a concentration. The soaking time is set to 1-60 min, and the appropriate soaking time allows aFGF to fully penetrate into the interior of the bacterial cellulose membrane, thereby improving the loading efficiency.

[0052] In a preferred embodiment, the width of the strip-shaped member is 1-5 mm, which makes the strip-shaped member have certain strength and is easy to weave and sew. The length is 15-25 cm, which is suitable for most sew requirements and ensures sufficient operating space. The thickness is 0.8-1.5 mm, and the uniform thickness helps to maintain the consistency and stability of the strip-shaped member.

[0053] In a preferred embodiment, the braiding pattern of the strip-like component is single helix, double helix or triple braid. These braiding patterns provide different appearance and strength characteristics, and a suitable pattern can be selected according to specific needs.

[0054] Preferably, the weaving pattern of the strip-shaped member is a double helix, and the bacterial cellulose suture thread prepared with double-strand bacterial cellulose into a double helix structure can not only further improve the mechanical properties, but also be more rounded and smooth to fit the wound. Specifically, the number of helices is 2 to 6 helices / 1 cm.

[0055] In one embodiment, the present invention provides a bacterial cellulose suture loaded with aFGF, which is prepared by the above-mentioned preparation method.

[0056] In one embodiment, the present invention provides a use of aFGF-loaded bacterial cellulose suture thread prepared by the above preparation method in medical dressings.

[0057] Specifically, the bacterial cellulose suture loaded with aFGF is used in the preparation of medical dressings suitable for contacting skin, organs and blood. Preferably, the medical dressings for contacting skin, organs and blood refer to medical devices used for suturing wounds of different organs of the human body.

[0058] The following is an analysis and explanation with specific examples.

[0059] See also Figure 3 As shown, a method for preparing aFGF-loaded bacterial cellulose suture comprises the following steps: S1, providing a bacterial cellulose membrane; the preparation of the bacterial cellulose membrane comprises the following steps: Step 1: Prepare expansion medium and production medium. The expansion medium includes 5g / L glucose, 5g / L yeast powder, 5g / L polypeptone and 1g / L citric acid. The production medium includes 30g / L glucose, 5g / L yeast powder, 5g / L polypeptone, 0.2g / L magnesium sulfate, 0.75g / L potassium dihydrogen phosphate and 1g / L citric acid. Step 2: Pick up the Acetobacter xylinum colonies and place them in an amplification culture medium, and culture them under shaking conditions of a rotation speed of 180 r / min and a temperature of 30° C. for 40 hours to obtain an Acetobacter xylinum amplification solution.

[0060] Step three, inoculate 60 mL of Acetobacter xylinum amplification solution into 1 L of production culture medium, add 5 mL of anhydrous ethanol and stir evenly, pour into a culture dish, and place the culture dish in a bacterial constant temperature incubator at 30° C. for static culture for 7 days to obtain a bacterial cellulose original film.

[0061] Step 4: Wash the bacterial solution and residues on the original bacterial cellulose membrane with distilled water, boil it in 0.2M sodium hydroxide solution for 60 minutes, and then wash it with distilled water several times to completely remove sodium hydroxide and other possible residues. Finally, spread it on a plate and dry it naturally to dry and shape the bacterial cellulose membrane.

[0062] S2, cutting the bacterial cellulose membrane into strip components, and then weaving the strip components into bacterial cellulose sutures. Specifically, using a ruler to cut the bacterial cellulose membrane into strip components of 5 mm width and 25 cm length according to the scale requirements. Then soak the bacterial cellulose strip components in distilled water and rinse them 3 times. Then weave the strip components into bacterial cellulose sutures in a double helix structure (4 helices / 1 cm) and dry them naturally. The obtained bacterial cellulose suture is recorded as BCS.

[0063] Methylene blue is used to color bacterial cellulose sutures. Methylene blue is a positively charged alkaline dye that can bind to the negative charges of DNA and RNA to form methylene blue-DNA or methylene blue-RNA complexes. When methylene blue binds to these nucleic acids, it absorbs light of specific wavelengths and reflects different colors, thereby staining the cell nucleus and cytoplasm. In the coloring process of bacterial cellulose sutures, methylene blue mainly stains the nucleic acids and protein components inside them.

[0064] The specific steps include: S21, Preparation of bacterial cellulose sutures: Make sure that the bacterial cellulose sutures are clean and free of impurities, and prepare an appropriate amount of methylene blue staining solution.

[0065] S22, Staining: Immerse the bacterial cellulose suture in the methylene blue staining solution, ensuring that it is completely immersed. The staining time can be adjusted as needed, but it usually takes from a few minutes to a few hours to achieve the desired staining effect.

[0066] S23, Rinse: Gently wash the dyed bacterial cellulose suture with deionized water or buffer to remove excess dye. The washing process should be gentle to avoid damaging the structure of the cellulose suture.

[0067] S24, drying: drying the washed bacterial cellulose suture thread naturally or using an appropriate drying method (such as low-temperature drying), and the obtained product is recorded as BC-MBS.

[0068] S3, soak the bacterial cellulose suture in the aFGF solution, and dry it to obtain the bacterial cellulose suture loaded with aFGF. Specifically, prepare an aFGF solution with a concentration of 10 μg / mL, soak the dried bacterial cellulose suture in the aFGF solution, and set the soaking time to 5 minutes. After the soaking is completed, take out the soaked bacterial cellulose suture, dry it naturally, and obtain the double helical bacterial cellulose suture loaded with aFGF. The obtained product is recorded as BC-MB-aFGFS.

[0069] The obtained product was characterized.

[0070] The surface morphology of the bacterial cellulose membrane was observed. Figure 4 As shown, the low-power and high-power scanning electron microscopy images of the bacterial cellulose membrane surface show that the bacterial cellulose membrane surface has a uniform texture.

[0071] The in vitro degradation of the prepared bacterial cellulose membrane was observed. The results are shown in Figure 5 As shown, the degradation rate of bacterial cellulose suture in PBS solution from 1 week to 8 weeks reached about 30% at 8 weeks.

[0072] The surface morphologies of bacterial cellulose suture BCS, methylene blue-stained bacterial cellulose suture BC-MBS, and methylene blue-stained double-helix bacterial cellulose suture BC-MB-aFGFS loaded with aFGF were observed. The results are shown in Figure 6 As shown, under a scanning electron microscope, dye particles are visible on the surface of the methylene blue-stained bacterial cellulose suture BC-MBS; and crystalline salts containing aFGF are visible on the surface of the methylene blue-stained double-helix bacterial cellulose suture BC-MB-aFGFS loaded with aFGF.

[0073] The diameter of bacterial cellulose suture BCS was measured to be 156.28 μm.

[0074] Tensile tests were performed on single-strand bacterial cellulose sutures, double-strand bacterial cellulose sutures BCS, and double-helix bacterial cellulose sutures treated with PH2.0, and the tensile strength and elongation were statistically analyzed. The results are shown in Figure 7 and Figure 8 As shown, the strain of the single-strand bacterial cellulose suture is 10.65 ± 0.33%, and the stress is 269.01 ± 12.82Mpa. The strain of the double-strand bacterial cellulose suture is 90.57 ± 0.65Mpa, 5.45 ± 0.21%. The strain of the double-helix bacterial cellulose suture after PH2.0 immersion treatment is 14.38 ± 0.89%, 254.25 ± 1.97 Mpa. The results show that the mechanical properties of the double-strand bacterial cellulose suture are better than those of the single-strand bacterial cellulose suture, and the effect of acid treatment on the mechanical properties of bacterial cellulose is not obvious. The surface morphology of the broken end of the bacterial cellulose suture after stretching was observed. The results are shown in Fig. 9 As shown, the cross section is flat and smooth, and the two bacterial cellulose fractures are consistent.

[0075] The cell compatibility of bacterial cellulose sutures was tested and the results are shown in Fig.10 As shown, bacterial cellulose sutures had no effect on cell activity, and bacterial cellulose sutures loaded with aFGF could significantly promote cell growth.

[0076] The blood compatibility of bacterial cellulose sutures was tested and the results are shown in Fig.11As shown, bacterial cellulose sutures do not cause hemolysis to the blood and are highly blood safe.

[0077] The in vivo biosafety of bacterial cellulose sutures was tested and the results are shown in Fig.12 As shown, bacterial cellulose will not cause tissue infection or lesions in the body and is degradable.

[0078] See also Fig.13 The HE images of bacterial cellulose sutures and commercial silk threads at different time points after subcutaneous embedding show that bacterial cellulose has good biosafety and degradability in vivo.

[0079] Test the effect of bacterial cellulose sutures on rat wound skin sutures, the results are shown in Fig.14 As shown, Fig.14 a is a visual image of the sutured wound. Fig.14 b is the HE image of the sutured wound. Fig.14 c is a Masson diagram of the sutured wound. The results show that the bacterial cellulose suture loaded with aFGF has a good effect in promoting wound healing.

[0080] Test the effect of bacterial cellulose sutures on rat tendon sutures, the results are shown in Fig.15 As shown, Fig.15 a is a visual image of the tendon suture wound. Fig.15 b is a schematic diagram of tendon specimen stretching after surgery. Fig.15 c is the tensile stress statistics of tendon specimens obtained after surgery. The results show that bacterial cellulose sutures loaded with aFGF have good biosafety and promote tendon healing.

[0081] Test the effect of bacterial cellulose sutures on gastric perforation in rats. The results are shown in Fig.16 As shown, bacterial cellulose sutures loaded with aFGF have a good effect on promoting the healing of gastric perforation wounds, with little rejection reaction and no obvious gastric adhesion.

[0082] Test the effect of bacterial cellulose sutures on rat intestinal incision suture, the results are shown in Fig.17 As shown, bacterial cellulose sutures loaded with aFGF have a good effect on promoting the healing of intestinal incision wounds, with a small rejection reaction and no obvious intestinal adhesion.

[0083] The above embodiments are only preferred embodiments for fully illustrating the present invention, and the protection scope of the present invention is not limited thereto. Any equivalent substitution or change made by a person skilled in the art based on the present invention is within the protection scope of the present invention.

Claims

1. A method for preparing aFGF-loaded bacterial cellulose suture, characterized in that: include: providing a bacterial cellulose membrane; cutting the bacterial cellulose membrane into strip-shaped components, and then weaving the strip-shaped components into bacterial cellulose sutures; The bacterial cellulose suture thread is immersed in the aFGF solution and then dried to obtain the bacterial cellulose suture thread loaded with aFGF.

2. The method for preparing aFGF-loaded bacterial cellulose suture according to claim 1, characterized in that: The preparation of the bacterial cellulose membrane comprises the following steps: Step 1, preparing expansion medium and production medium; Step 2, picking up Acetobacter xylinum colonies and placing them in an amplification medium, shaking and culturing them to obtain Acetobacter xylinum amplification liquid; Step 3, inoculating the Acetobacter xylinum amplification solution into the production culture medium, adding anhydrous ethanol and stirring evenly, pouring into a culture dish, and placing the culture dish in a bacterial constant temperature incubator for static culture to obtain a bacterial cellulose original film; Step 4: Use distilled water to wash away the bacterial solution and residues on the original bacterial cellulose membrane, boil it in a sodium hydroxide solution, then wash it with distilled water for multiple times, and finally spread it on a plate to dry naturally to obtain a bacterial cellulose membrane.

3. The method for preparing aFGF-loaded bacterial cellulose suture according to claim 2, characterized in that: The amplification medium in step 1 comprises 3-7 g / L of glucose, 3-7 g / L of yeast powder, 3-7 g / L of polypeptone and 0.5-1.2 g / L of citric acid; And / or, the production medium in step 1 includes 20-40 g / L of glucose, 3-7 g / L of yeast powder, 3-7 g / L of polypeptone, 0.1-0.25 g / L of magnesium sulfate, 0.05-0.1 g / L of potassium dihydrogen phosphate and 0.5-1.2 g / L of citric acid.

4. The method for preparing aFGF-loaded bacterial cellulose suture according to claim 2, characterized in that: The process parameters of the shaking culture in step 2 include: the rotation speed is set to 150~180r / min, the temperature is set to 28~30°C, and the shaking culture time is set to 36~48h.

5. The method for preparing aFGF-loaded bacterial cellulose suture according to claim 2, characterized in that: In step 3, 40-80 mL of Acetobacter xylinum amplification solution and 3-8 mL of anhydrous ethanol are added to every 1 L of production culture medium, the temperature of the bacterial constant temperature incubator is set to 28-30° C., and the static culture time is set to 5-10 days.

6. The method for preparing aFGF-loaded bacterial cellulose suture according to claim 1, characterized in that: The concentration of aFGF solution was 1-100 μg / L, and the immersion time was set at 1-60 min.

7. The method for preparing aFGF-loaded bacterial cellulose suture according to claim 1, characterized in that: The strip-shaped component has a width of 1-5 mm, a length of 15-25 cm, and a thickness of 0.8-1.5 mm.

8. The method for preparing aFGF-loaded bacterial cellulose suture according to claim 1, characterized in that: The braiding pattern of the strip-like components is single helix, double helix or triple braid.

9. A bacterial cellulose suture loaded with aFGF, characterized in that: The method is prepared according to any one of claims 1 to 8.

10. Use of the bacterial cellulose suture loaded with aFGF prepared by the preparation method according to any one of claims 1 to 8 in medical dressings.

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