Method for preparing a functional bacterial cellulose-based nerve conduit with anti-inflammatory and pro-neural repair functions

Abstract

The application discloses a preparation method of a functional bacterial cellulose-based nerve conduit with anti-inflammatory and nerve repair promoting functions, and belongs to the field of microbial medical materials and tissue engineering. The application adds polyvinyl alcohol into a characteristic culture medium, co-cultures with Acetobacter xylinum, and adds curcumin in the culture system, to obtain a bacterial cellulose film containing polyvinyl alcohol and curcumin through in-situ synthesis, and then the bacterial cellulose film is purified, freeze-dried, flattened, curled, sutured and shaped to prepare the nerve conduit with a hollow tubular structure. The application utilizes the tackifying and hydrogen bond anchoring effects of polyvinyl alcohol to realize efficient and stable loading of curcumin in the three-dimensional network of bacterial cellulose. The infrared spectrum, X-ray diffraction, animal implantation experiment and cell experiment verify that the nerve conduit has good biocompatibility, significant anti-inflammatory performance and nerve repair promoting function. The method is simple and green, and the prepared nerve conduit has wide application prospects in the field of peripheral nerve injury repair.

Description

Technical Field

[0001] This invention belongs to the field of microbial medical materials and tissue engineering, specifically relating to a method for preparing a functional bacterial cellulose-based nerve conduit with anti-inflammatory and nerve-repairing properties. Background Technology

[0002] Peripheral nerve injury is a common clinical condition, often caused by trauma, tumor resection, or compressive injury. It can lead to sensory and motor dysfunction, severely impacting patients' quality of life. Currently, autologous nerve transplantation is the gold standard for repairing long-segment nerve defects, but it has limitations such as limited donor availability, loss of donor site function, and neuroma formation. Therefore, developing artificial nerve conduits with good biocompatibility, structural stability, and functional modifications has become a research hotspot.

[0003] Polyvinyl alcohol (PVA), as a water-soluble polymer, has a molecular chain rich in hydroxyl groups. It can interact with curcumin and bacterial cellulose through hydrogen bonds, which can both increase the viscosity of the culture medium to prevent the aggregation of hydrophobic curcumin and act as a "molecular anchor" to enhance the immobilization stability of curcumin in the bacterial cellulose network.

[0004] Bacterial cellulose (BC) is a natural polymeric nanomaterial synthesized by microorganisms such as *Acetobacter xylinum*. Its unique three-dimensional nanofiber network structure endows it with high crystallinity, high water retention, excellent mechanical strength, and good biocompatibility, and it has been widely used in tissue engineering scaffolds, wound dressings, and other fields. Studies have shown that Schwann cells can grow and migrate normally on bacterial cellulose membranes, suggesting its potential application in nerve repair.

[0005] However, bacterial cellulose alone lacks the function of actively regulating the damaged microenvironment, making it difficult to effectively inhibit the inflammatory response after nerve injury and promote nerve regeneration. Curcumin (Cur) is a natural polyphenol compound with multiple biological activities, including anti-inflammatory, antioxidant, and nerve regeneration-promoting effects. However, curcumin has poor water solubility and low bioavailability. How to achieve efficient and stable loading and controlled release of curcumin in bacterial cellulose is a pressing technical problem that needs to be solved. Summary of the Invention

[0006] The purpose of this invention is to provide a method for preparing a functional bacterial cellulose-based nerve conduit with anti-inflammatory and nerve repair functions, so as to solve the problem that existing nerve conduits lack the function of actively regulating the inflammatory microenvironment and promoting nerve regeneration.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0008] A method for preparing a functional bacterial cellulose-based nerve conduit with anti-inflammatory and nerve repair functions includes the following steps:

[0009] (1) Polyvinyl alcohol was added to the characteristic culture medium and heated in a water bath at 95 °C for 1 h to dissolve it. After autoclaving and cooling, bacterial cellulose synthesis culture medium was obtained.

[0010] The refrigerated Acetobacter xylose bacterial culture was inoculated into sterilized liquid seed culture medium at a 10% inoculation rate and cultured in a shaker at 30 ℃ and 200 rpm for 24 h to obtain seed culture. Separately, curcumin was dissolved in anhydrous ethanol to prepare a 1-3 mg / mL curcumin solution, which was added to the synthetic culture medium at a volume fraction of 2% (v / v). The seed culture was then inoculated at a 15% inoculation rate and cultured statically at 30 ℃ for 7 days to obtain a bacterial cellulose membrane containing curcumin and polyvinyl alcohol.

[0011] (2) The bacterial cellulose membrane obtained in step (1) is first rinsed with deionized water to remove residual culture medium and soaked in deionized water for 2 days; it is then adjusted to neutral with 0.1 mol / L sodium hydroxide solution and washed repeatedly with deionized water until the membrane surface is neutral to obtain purified bacterial cellulose membrane.

[0012] (3) Soak the purified bacterial cellulose membrane in PBS buffer until the curcumin release concentration reaches 2-3 mg / L before proceeding to the next step; otherwise, adjust the curcumin concentration and repeat the soaking step to obtain a bacterial cellulose composite membrane loaded with a specific concentration of curcumin.

[0013] (4) Freeze the bacterial cellulose membrane obtained in step (3) in a -40 ℃ freezer for 24 h, and then freeze-dry it in a freeze dryer for 48-72 h to obtain a freeze-dried bacterial cellulose membrane.

[0014] (5) Place the freeze-dried bacterial cellulose membrane from step (4) in a sterile environment and flatten it to form a sheet membrane with uniform thickness and a smooth surface.

[0015] (6) Cut the sheet membrane to a predetermined length and roll it into a tubular structure along its longitudinal direction so that the two sides of the membrane are attached to each other to form a hollow cavity;

[0016] (7) While maintaining the tubular structure, absorbable surgical sutures are used to continuously or intermittently suture the edges of the fitting along the axial direction to obtain a suture tube;

[0017] (8) The suture tube is reshaped to make its inner lumen unobstructed and its wall structure uniform, and finally a bacterial cellulose-based nerve conduit with a stable hollow structure is formed.

[0018] The formula for the characteristic culture medium used in step (1) is: 1 L deionized water, 75 g glucose, and 15 g yeast powder.

[0019] The degree of alcoholysis of the polyvinyl alcohol used in step (1) is 98-99% (mol / mol).

[0020] After adding polyvinyl alcohol in step (1), the mass concentration of polyvinyl alcohol in the characteristic culture medium is 3%.

[0021] The autoclaving conditions for the culture medium in step (1) are 121 °C for 20 min.

[0022] The formula for the liquid seed culture medium used in step (1) is: 100 mL deionized water, 7.5 g glucose, and 1.5 g yeast powder.

[0023] In step (1), the concentration of curcumin is 2 mg / mL.

[0024] The beneficial effects of this invention are:

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] (1) The present invention uses bacterial cellulose as the base material, and its three-dimensional nanofiber network structure provides an ideal scaffold for cell growth, with good biocompatibility and structural stability.

[0027] (2) In this invention, polyvinyl alcohol is introduced in the in-situ synthesis stage of bacterial cellulose. Its high viscosity is used to prevent hydrophobic curcumin from aggregating, and the curcumin is loaded efficiently and stably in the bacterial cellulose network through hydrogen bonds.

[0028] (3) The curcumin loaded in this invention has clear anti-inflammatory and nerve repair functions, which can effectively inhibit the early inflammatory response after implantation, promote nerve axon regeneration and target muscle function recovery, and the higher dose of curcumin has better effects.

[0029] (4) Infrared spectroscopy and X-ray diffraction analysis confirmed that polyvinyl alcohol and curcumin were uniformly dispersed in the bacterial cellulose network in an amorphous form, forming a stable hydrogen bond interaction system.

[0030] (5) Subcutaneous implantation model, sciatic nerve defect model and cell proliferation experiment in rats showed that the nerve conduit prepared in this invention has good biosafety, in vivo anti-inflammatory and nerve repair effects, and has clinical application potential. Attached Figure Description

[0031] Figure 1 The Fourier transform infrared spectrum of the composite material of this invention;

[0032] Figure 2The X-ray diffraction pattern of the composite material of this invention;

[0033] Figure 3 Image of hematoxylin-eosin (HE) staining of tissue at the subcutaneous implantation site;

[0034] Figure 4 Immunohistochemical staining of CD68 in tissue at the subcutaneous implantation site;

[0035] Figure 5 This is a statistical chart showing the recovery rate of postoperative motor nerve conduction velocity.

[0036] Figure 6 A statistical chart for assessing postoperative target muscle atrophy recovery (gastrocnemius muscle wet weight ratio);

[0037] Figure 7 This is a toluidine blue staining image of regenerated nerves 12 weeks post-surgery.

[0038] Figure 8 This is a diagram of the cell CCK-8 proliferation experiment of the composite material of the present invention. Detailed Implementation

[0039] The specific embodiments of the present invention will be further described in detail below with reference to examples.

[0040] Example 1: A method for preparing a functional bacterial cellulose-based nerve conduit with anti-inflammatory and nerve repair functions.

[0041] (1) Add polyvinyl alcohol with a degree of alcoholysis of 98%-99% (mol / mol) to the characteristic culture medium to make the mass concentration of polyvinyl alcohol in the characteristic culture medium 3%; heat in a water bath at 95 ℃ for 1 h to dissolve it completely, and then autoclave at 121 ℃ for 20 min and cool to obtain bacterial cellulose synthesis culture medium.

[0042] The formula for the characteristic culture medium is: 1 L deionized water, 75 g glucose and 15 g yeast powder. The preparation method is: add 75 g glucose and 15 g yeast powder to 1 L deionized water at room temperature, stir to dissolve, and make the nutrients evenly distributed.

[0043] Meanwhile, the refrigerated Acetobacter xylinum bacterial solution was inoculated into liquid seed culture medium at an inoculation rate of 10%, and cultured in a shaker at 30 ℃ and 200 rpm for 24 h to obtain seed solution;

[0044] The liquid seed culture medium consists of 100 mL deionized water, 7.5 g glucose and 1.5 g yeast powder. The preparation method is as follows: add 7.5 g glucose and 1.5 g yeast powder to 100 mL deionized water at room temperature, stir to dissolve, and make the nutrients evenly distributed.

[0045] Curcumin was dissolved in anhydrous ethanol to prepare a curcumin / ethanol solution with a concentration of 1 mg / mL. The solution was then added to the above-mentioned synthetic culture medium at a volume fraction of 2% (v / v). Subsequently, the seed culture was inoculated at a rate of 15% and cultured statically at 30 °C for 7 days to obtain a bacterial cellulose membrane containing curcumin and polyvinyl alcohol.

[0046] (2) The bacterial cellulose membrane obtained in step (1) is first rinsed with deionized water to remove residual culture medium, soaked in deionized water for 2 days, adjusted to neutral with 0.1 mol / L sodium hydroxide solution, and then repeatedly washed with deionized water until the membrane surface is neutral as detected by pH test paper, thus obtaining purified bacterial cellulose membrane.

[0047] (3) Soak the bacterial cellulose membrane in PBS buffer and determine the curcumin concentration in the PBS extract by liquid chromatography. After the curcumin release concentration of the loaded membrane reaches 2-3 mg / L, proceed to the next step.

[0048] (4) The bacterial cellulose membrane obtained in step (3) was placed in a -40 ℃ freezer for 24 h and then freeze-dried in a freeze dryer for 48-72 h to obtain the freeze-dried bacterial cellulose membrane.

[0049] (5) Place the freeze-dried bacterial cellulose membrane obtained in step (4) in a sterile operating environment and flatten it to form a sheet membrane with uniform thickness and smooth surface.

[0050] (6) The sheet-like film is cut to a predetermined length and rolled into a tube along its longitudinal direction so that the two sides of the film are attached to each other to form a hollow tubular cavity.

[0051] (7) While maintaining the tubular shape, absorbable surgical sutures are used to continuously suture and fix the edges of the fitting along the axial direction.

[0052] (8) The sutured tubular cavity is reshaped to make its inner cavity unobstructed and its wall structure uniform, and finally a bacterial cellulose-based nerve conduit with a stable hollow structure is formed.

[0053] Example 2: Preparation method of functional bacterial cellulose-based nerve conduit with anti-inflammatory and nerve repair functions

[0054] It is basically the same as Example 1, except that:

[0055] In Example 2, step (1) involves preparing a bacterial cellulose membrane containing curcumin and polyvinyl alcohol using a 2 mg / ml curcumin / ethanol solution. The other steps are the same as in Example 1.

[0056] Example 3: Detection of effective components in bacterial cellulose membranes in nerve conduits

[0057] 3.1 Functional Group Characterization

[0058] Fourier transform infrared spectroscopy was used to analyze pure bacterial cellulose BC, pure curcumin Cur, bacterial cellulose membrane of step (4) of Example 1 (hereinafter referred to as BC / PVA / 1Cur) and bacterial cellulose membrane of Example 2 (hereinafter referred to as BC / PVA / 2Cur). Among them, 1Cur and 2Cur in BC / PVA / 1Cur and BC / PVA / 2Cur correspond to the curcumin content of 1 mg / mL and 2 mg / mL in the curcumin / ethanol solution added to the culture medium, respectively.

[0059] The results are as follows Figure 1 As shown, 3345 cm -1 The vibrational peak corresponding to the -OH group on the BC molecule is 2900 cm⁻¹. -1 This is the stretching vibration peak of the methyl and methylene groups on the glucose ring, at 1052 cm⁻¹. -1 The peak at 3500-3000 cm⁻¹ represents the stretching vibration of the CO bond, primarily originating from the β-1,4-glycosidic bond in the BC structure. Besides the terminal C=C group, the PVA molecule is dominated by -CH₂ and -OH groups. The BC scaffold exhibits peaks at 3500-3000 cm⁻¹. -1 The peak at this location exhibits a relatively broad hydroxyl band, while different BC / PVA composite scaffolds show even broader bands, indicating an increased number of hydroxyl groups. Furthermore, the peak at this location is 3285 cm⁻¹ after the addition of PVA. -1 The shift indicates that it is caused by hydrogen bonding between PVA and BC molecules. Meanwhile, the presence of characteristic peaks for PVA, such as ether bonds and C=C stretching vibrations of terminal vinyl groups, on the composite scaffold indicates that PVA was successfully bound.

[0060] Pure Curl at 1593 cm -1 and 1513 cm -1 There is a distinct aromatic ring skeletal vibration peak at 844 cm⁻¹. -1 and 804cm -1 Nearby, out-of-plane bending vibration peaks of aromatic CH can be observed. These are characteristic absorption peaks of Cur, proving that Cur has been successfully loaded into the BC / PVA scaffold. At the same time, the OH absorption bands of the BC / PVA / 1Cur and BC / PVA / 2Cur composites are significantly broadened, and a dense hydrogen bond network is formed between the PVA on the surface, Cur, and BC, confirming that PVA acts as a molecular anchor to achieve stable immobilization of Cur.

[0061] 3.2 X-ray diffraction (XRD) characterization

[0062] X-ray diffraction was used to analyze pure bacterial cellulose (BC), pure curcumin (Cur), BC / PVA / 1Cur, and BC / PVA / 2Cur composites. The results are as follows: Figure 2 As shown, the two composite materials exhibit characteristic diffraction peaks of cellulose type I at 2θ=14.6°, 16.8° and 22.6°, and no independent diffraction peaks of crystalline PVA or Cur are observed. This indicates that PVA and Cur are uniformly dispersed in the BC network in an amorphous form and moderately modify the supramolecular structure of BC. The crystallographic nature of its nanofiber skeleton remains unchanged.

[0063] The above results indicate that PVA and curcumin are not simply physically mixed, but rather achieve molecular-level composite formation with the BC network in an amorphous form. While PVA exerts its thickening and hydrogen bond-locking functions, it also increases the amorphous region and accessibility of the network.

[0064] Example 4: Verification of anti-inflammatory effect in vivo

[0065] To evaluate the in vivo biocompatibility and anti-inflammatory function of the bacterial cellulose membrane in the nerve conduit of this invention, a subcutaneous implantation model was established in SD rats. Four groups of materials—blank control, BC / PVA membrane, BC / PVA / 1Cur, and BC / PVA / 2Cur—were implanted subcutaneously into the posterior neck of rats. The materials and surrounding tissue were collected at weeks 1, 2, and 4 post-implantation. After paraffin embedding and sectioning, HE staining and CD68 (pan-macrophage marker) immunohistochemical staining were performed, and full-field imaging was acquired using a digital slide scanner.

[0066] The results are as follows Figure 3 , Figure 4 As shown, one week after implantation, significant acute inflammatory responses were observed in the surrounding tissues of each group. HE staining revealed extensive inflammatory cell infiltration and tissue edema, while CD68 staining showed extensive macrophage recruitment and activation.

[0067] Two weeks after implantation, the control group and the BC / PVA group entered the chronic inflammation and fibrosis stage, forming thicker and denser fibrous capsules, with persistent macrophages observed. The BC / PVA / 1Cur and BC / PVA / 2Cur groups, however, showed better inflammation resolution and tissue repair. Four weeks after implantation, the fibrous capsules surrounding the BC / PVA / 1Cur and BC / PVA / 2Cur groups were thinner, looser, and more vascularized, with macrophage-related signals nearly returning to baseline levels, while the control group and the BC / PVA group showed no significant changes.

[0068] The above results confirm that, through in-situ compounding with curcumin, the bacterial cellulose membrane of this invention can effectively regulate the foreign body reaction after implantation, inhibit early acute inflammation, and promote the resolution of later inflammation, demonstrating excellent in vivo anti-inflammatory and tissue compatibility. This provides a key technical basis for applying this material to implantable medical devices such as nerve condyloma acuminata to create a local microenvironment conducive to regeneration.

[0069] Example 5: Verification of the nerve-repairing effect

[0070] 5.1 Establishment of a Standard Sciatic Nerve Defect and Repair Model

[0071] Healthy adult SD rats were used. After aseptic preparation and anesthesia, a longitudinal incision was made in the posterior thigh of the right hind limb. The sciatic nerve was exposed and freed by dissecting layer by layer. A complete transverse defect was created in the middle segment of the sciatic nerve using microsurgical scissors. Subsequently, according to pre-set groups: Autologous nerve transplantation group (positive control): The excised nerve segment was inverted, and its proximal and distal ends were sutured end-to-end to the two ends of the sciatic nerve using non-invasive microsurgical sutures; Experimental conduit implantation group: The prepared corresponding nerve conduits (BC / PVA conduit, BC / PVA / 1Cur conduit of Example 1, and BC / PVA / 2Cur conduit of Example 2) were placed at the nerve defect. The BC / PVA conduit was anastomosed end-to-end to the proximal and distal ends of the sciatic nerve using the same microsurgical suturing technique as in Example 1. After nerve repair, the biceps femoris muscle fascia and skin incision were sutured sequentially. The animals were housed separately after surgery.

[0072] 5.2 Electrophysiological assessment

[0073] The experiment was divided into four groups: BC / PVA catheter group, BC / PVA / 1Cur group, BC / PVA / 2Cur group, and autologous nerve transplantation group.

[0074] To objectively quantify the recovery of electrophysiological function of regenerated nerves, in vivo electrophysiological tests were performed on rats in each group at the end of the 12th week after surgery.

[0075] The conduction velocity of motor nerves is assessed by calculating the ratio of the operated side to the healthy side.

[0076] like Figure 5 As shown, the recovery rate of motor nerve conduction velocity was highest in the autologous transplantation group (83.0%). The recovery rate was lowest in the pure BC / PVA catheter group (46.0%), while the curcumin-loaded catheter significantly improved conduction function, with the BC / PVA / 2Cur group achieving a recovery rate of 71.0%.

[0077] Electrophysiological results show that the nerve conduit of the present invention can not only promote the regeneration of nerve structures, but also significantly restore their electrical signal conduction. Moreover, the recovery effect of the high-dose drug-loaded group is close to the standard of autologous transplantation, which confirms its effectiveness in promoting nerve repair from a physiological perspective.

[0078] 5.3 Assessment of Target Muscle Atrophy Recovery

[0079] Successful restoration of neurological function is ultimately reflected in the recovery of effector organs. At the end of the 12th week post-surgery, the atrophy recovery of the motor target organs was assessed by measuring the wet weight ratio of the gastrocnemius muscle and the circumference ratio of the calf.

[0080] The experiment was divided into four groups: BC / PVA catheter group, BC / PVA / 1Cur group, BC / PVA / 2Cur group, and autologous nerve transplantation group.

[0081] like Figure 6 As shown, the autologous transplant group had the highest wet weight ratio of gastrocnemius muscle (69.0%), while the pure BC / PVA catheter group had a ratio of only 40.0% due to poor nerve reinnervation and severe muscle atrophy. The wet weight ratios of the BC / PVA / 1Cur group and the BC / PVA / 2Cur group increased to 50.0% and 54.0%, respectively, with the high-dose BC / PVA / 2Cur group showing better results than the low-dose BC / PVA / 1Cur group.

[0082] The results demonstrate that, compared to simple structural conduits, the curcumin-loaded functionalized nerve conduits of the present invention can more effectively promote the reinnervation of nerves to target muscles and significantly reduce denervated muscle atrophy, thus proving their superiority in functional repair at the effector organ level.

[0083] 5.4 Toluidine Blue Staining

[0084] To evaluate the nerve regeneration effect guided by the material of this invention, toluidine blue staining was performed on the mid-segment of the regenerated nerve harvested at the end of the 12th week post-surgery to observe the regeneration of myelinated nerve fibers. Analysis of the stained sections after digital scanning showed significant differences in the morphology of the regenerated nerves among the groups. The experiment was divided into 5 groups: the BC / PVA catheter group, the BC / PVA / 1Cur group, the BC / PVA / 2Cur group, the control group (no surgery), and the autologous nerve transplantation group.

[0085] See results Figure 7 The autologous nerve transplantation group showed dense, neatly arranged myelinated nerve fibers with clear myelin staining and a morphology close to that of normal nerves.

[0086] In the BC / PVA group (without drug loading), myelin nerve fibers were visible in the regenerated nerves. Compared with the control, the overall density was lower, the fiber arrangement was looser, and the myelin sheath thickness was uneven. Regenerated fiber clusters of varying sizes were visible in some areas.

[0087] The BC / PVA / 1Cur group (loaded with low-dose curcumin) showed significantly higher myelin fiber density than the BC / PVA group, with more orderly fiber arrangement and a clearer and more complete myelin sheath outline.

[0088] The BC / PVA / 2Cur group (loaded with high-dose curcumin) showed superior regenerative morphology compared to the BC / PVA / 1Cur group. Its myelinated nerve fiber density was higher than that of the BC / PVA / 1Cur group, approaching the level of the positive control. The fibers were neatly and compactly arranged, and the myelin sheath was uniform and of good thickness, presenting a mature regenerative nerve structure close to the physiological state.

[0089] Experimental results show that the curcumin-loaded bacterial cellulose membrane of the present invention can significantly promote structural regeneration after nerve loss. In particular, the high-dose drug-loaded group can effectively guide the regeneration of high-density, orderly arranged and well-myelinated myelinated nerve fibers, laying a solid anatomical foundation for the recovery of nerve function.

[0090] Example 6 Cytotoxicity test

[0091] To systematically evaluate the effects of the catheter material of the present invention on the viability and proliferation of RSC96 Schwann cells, cytotoxicity and proliferation were detected using the CCK-8 assay. The experiment consisted of five groups: a pure BC group, a BC / PVA group, a BC / PVA / 1Cur group, a BC / PVA / 2Cur group, and a control group containing only complete culture medium.

[0092] The extracts from each group were added to complete culture medium to obtain culture medium. RSC96 cells were co-cultured with complete culture medium, BC extract + complete culture medium, BC / PVA composite extract + complete culture medium, BC / PVA / 1Cur extract + complete culture medium, and BC / PVA / 2Cur extract + complete culture medium, respectively. The relative viability of cells in each group was then detected.

[0093] Experimental results show that ( Figure 8 Compared with the control group, both the pure BC group and the BC / PVA group showed higher cell viability, indicating that BC and PVA are non-toxic to cells and have a certain protective effect. Furthermore, in the BC / PVA / 1Cur group, cell viability increased to 115% after loading a low dose of Cur onto the BC / PVA composite material; the cell viability in the BC / PVA / 2Cur group increased to 125%. These experimental results demonstrate that the Cur-loaded composite material not only has no cytotoxicity but also significantly promotes Schwann cell proliferation, exhibiting a concentration-dependent enhancement effect.

[0094] Combination Figure 8 It can be seen that with the introduction of Cur and the increase of loading, the viability of RSC96 cells gradually increases, indicating that the BC / PVA / Cur composite catheter material of the present invention has good biocompatibility and cell proliferation promotion function.

Claims

1. A method for preparing a functional bacterial cellulose-based nerve conduit with anti-inflammatory and nerve-repairing functions, characterized in that, Includes the following steps: (1) Polyvinyl alcohol was added to the characteristic culture medium and heated in a water bath at 95 °C for 1 h to dissolve it. After autoclaving and cooling, bacterial cellulose synthesis culture medium was obtained. The refrigerated Acetobacter xylose bacterial culture was inoculated into sterilized liquid seed culture medium at a 10% inoculation rate and cultured in a shaker at 30°C and 200 rpm for 24 h to obtain seed culture. Separately, curcumin was dissolved in anhydrous ethanol to prepare a 1-3 mg / mL curcumin solution, which was added to the synthetic culture medium at a volume fraction of 2% (v / v). The seed culture was then inoculated at a 15% inoculation rate and cultured statically at 30°C for 7 days to obtain a bacterial cellulose membrane containing curcumin and polyvinyl alcohol. (2) The bacterial cellulose membrane obtained in step (1) is first rinsed with deionized water to remove residual culture medium and soaked in deionized water for 2 days; it is then adjusted to neutral with 0.1 mol / L sodium hydroxide solution and washed repeatedly with deionized water until the membrane surface is neutral to obtain purified bacterial cellulose membrane. (3) Soak the purified bacterial cellulose membrane in PBS buffer until the curcumin release concentration reaches 2-3 mg / L before proceeding to the next step; otherwise, adjust the curcumin concentration and repeat the soaking step to obtain a bacterial cellulose composite membrane loaded with a specific concentration of curcumin. (4) Freeze the bacterial cellulose membrane obtained in step (3) in a -40 ℃ freezer for 24 h, and then freeze-dry it in a freeze dryer for 48-72 h to obtain a freeze-dried bacterial cellulose membrane. (5) Place the freeze-dried bacterial cellulose membrane from step (4) in a sterile environment and flatten it to form a sheet membrane with uniform thickness and a smooth surface. (6) Cut the sheet membrane to a predetermined length and roll it into a tubular structure along its longitudinal direction so that the two sides of the membrane are attached to each other to form a hollow cavity; (7) While maintaining the tubular structure, absorbable surgical sutures are used to continuously or intermittently suture the edges of the fitting along the axial direction to obtain a suture tube; (8) The suture tube is reshaped to make its inner lumen unobstructed and its wall structure uniform, and finally a bacterial cellulose-based nerve conduit with a stable hollow structure is formed.

2. The preparation method according to claim 1, characterized in that, The formula for the characteristic culture medium used in step (1) is: 1 L deionized water, 75 g glucose, and 15 g yeast powder.

3. The preparation method according to claim 1, characterized in that, The degree of alcoholysis of the polyvinyl alcohol used in step (1) is 98%-99% (mol / mol).

4. The preparation method according to claim 1, characterized in that, After adding polyvinyl alcohol in step (1), the mass concentration of polyvinyl alcohol in the characteristic culture medium is 3%.

5. The preparation method according to claim 1, characterized in that, The autoclaving conditions for the culture medium in step (1) are 121 °C for 20 min.

6. The preparation method according to claim 1, characterized in that, The formula for the liquid seed culture medium used in step (1) is: 100 mL deionized water, 7.5 g glucose, and 1.5 g yeast powder.

7. The preparation method according to claim 1, characterized in that, The concentration of curcumin in step (1) is 2 mg / mL.

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