Absorbable anti-inflammatory catgut and method for making same

Abstract

The application discloses absorbable anti-inflammatory catgut and a manufacturing method thereof, and belongs to the technical field of biomedical materials. The catgut is prepared from a sheep intestinal submucosa, and is prepared through the steps of cleaning and swelling, degreasing, submucosa stripping, decellularization, winding and dehydration shaping. An enzyme treatment step is introduced in the decellularization step, which significantly reduces the immunogenicity of the material and endows the catgut with active anti-inflammatory properties. The catgut prepared by the method has less cell residues, complete collagen structure, appropriate mechanical strength, slight inflammatory reaction after being implanted into a body, fast wound healing speed and excellent biocompatibility, and is suitable for suture of various surgical operations.

Description

Technical Field

[0001] This invention relates to the field of biomedical materials technology, specifically to an absorbable catgut suture with low immunogenicity and active anti-inflammatory function, and its manufacturing method. Background Technology

[0002] Catgut sutures, as a traditional absorbable surgical suture material, are widely used in clinical practice. However, traditional catgut sutures have two main drawbacks: first, residual cellular components and genetic material (DNA / RNA) in the material can trigger an immune rejection reaction; second, the material itself does not have anti-inflammatory properties, often leading to varying degrees of inflammation after implantation, affecting the quality of wound healing.

[0003] Existing technologies employ chemical methods (such as SDS and Triton X-100) for decellularization, which can partially remove cellular components, but have limited effectiveness in clearing genetic material and inflammatory mediators in the extracellular matrix, resulting in incomplete reduction of immunogenicity and poor anti-inflammatory effects.

[0004] Therefore, developing a method for preparing catgut that can completely reduce immunogenicity and endow it with active anti-inflammatory function has become a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide an absorbable anti-inflammatory catgut and its manufacturing method, thereby solving the technical problem that traditional catgut has high immunogenicity and is prone to causing inflammatory reactions.

[0006] The technical solution adopted in this invention is: a method for manufacturing absorbable anti-inflammatory catgut, comprising the following steps:

[0007] S1. Pretreatment: Take fresh sheep intestines, clean them, and immerse them in a 0.5% to 1.5% sodium bicarbonate solution at 3 to 5°C for more than 24 hours; then transfer them to a 10% to 30% sodium chloride solution and soak for 10 to 25 minutes to degrease them, and rinse with pure water.

[0008] S2. Submucosal stripping: Cut the pre-treated sheep intestines into 30-70 cm long segments, cut them longitudinally, lay them with the serosa layer facing upwards, scrape off the outer serosa layer, muscle layer and inner mucosa layer, and retain the submucosal layer.

[0009] S3. Decellularization treatment: Immerse the submucosal layer in a 0.5%–1.5% sodium dodecyl sulfate solution and shake at 3–5°C and 100–150 rpm / min for at least 24 hours.

[0010] S4. Discard the SDS solution and replace it with a mixed solution of ammonia and Triton X-100 for 16–30 hours; the mass concentration of ammonia in the mixed solution is 0.08%–0.12%, and the mass concentration of Triton X-100 is 0.05%–0.15%.

[0011] S5. Discard the mixed solution and soak the sample in an enzyme preparation for 3-6 hours; then rinse with ultrapure water for at least 2 days, then sterilize with a 0.7%-1.2% (w / w) double-antibiotic solution for 0.8-1.5 hours, and rinse with sterile water.

[0012] S6. Winding and Dehydration: The decellularized submucosal layer is cut into strips 0.3-0.7 cm wide and 30-70 cm long. The strips are wound into threads with constant tension using a twisting machine. After fixing, the threads are placed in an environment of 3-5℃ for dehydration and shaping to obtain absorbable anti-inflammatory catgut.

[0013] As a further improvement of the present invention, the enzyme preparation includes DNase I, and the concentration of the enzyme preparation is 0.5–2 mg / mL. More preferably, the enzyme preparation is a complex enzyme preparation composed of DNase I and endo-β-glucuronidase.

[0014] The mass ratio of DNase I to endo-β-glucuronidase in the compound enzyme preparation is preferably 1:0.5 to 2.

[0015] As a further improvement of the present invention, the treatment of the compound enzyme preparation is carried out under the conditions of pH 7.0-7.5 and 36-38°C.

[0016] As a further improvement of the present invention, in step S5, the ultrapure water rinsing is performed three times a day, morning, noon, and evening, until the pH and conductivity of the aqueous phase stabilize. This method ensures the complete removal of chemical reagents and enzyme preparations through strict water quality monitoring and frequent water changes, avoiding residues that could trigger subsequent inflammatory responses.

[0017] In step S6 of this invention, dehydration is preferably carried out by natural air drying or freeze drying in order to effectively stabilize the helical structure of collagen fibers and give catgut good mechanical strength and shape retention ability.

[0018] This invention also discloses an absorbable anti-inflammatory catgut, which is prepared by the method of this invention. The residual cell nucleus rate of this catgut is less than 5%, and within 7 days after implantation, the expression level of pro-inflammatory factor TNF-α decreases by more than 40%, while the expression level of anti-inflammatory factor IL-10 increases by more than 50%.

[0019] The beneficial effects of this invention are: 1) Significantly reduced immunogenicity: Through the synergistic effect of the compound enzyme preparation, the residual rate of cell nuclei is reduced from more than 25% in traditional catgut to less than 5%, fundamentally solving the problem of immune rejection. 2) Outstanding active anti-inflammatory function: The loaded enzyme preparation can continuously degrade inflammatory mediators, promoting the transformation of the immune environment towards anti-inflammatory, with TNF-α expression decreasing by more than 40% and IL-10 expression increasing by more than 50%. 3) Improved wound healing quality: Animal experiments show that the wound healing rate using the catgut of this invention is significantly improved, and inflammatory cell infiltration is significantly reduced. 4) Optimized process parameters: The parameters of each step have been systematically optimized, improving the stability and reproducibility of the process while ensuring the treatment effect. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the immunohistochemical results after suturing the skin of SD rats with catgut in a specific implementation method.

[0021] Figure 2 This is a schematic diagram of the catgut preparation process. A. Peeling the serosa, muscle layer, and mucosa; B. Partially peeled intestinal tissue; C. Completely peeled intestinal tissue; D. Immersing the submucosa in SDS with continuous stirring; E. Subsequent treatment with a mixture of ammonia and Triton-X100; F. Enzyme treatment followed by ultrapure water washing; G. Sterilization treatment with a penicillin-streptomycin solution; H. Ultrapure water washing; I. Cutting to a width of 0.5 cm; J. Twisting into thread using a twisting machine; K. Drying treatment; L. The catgut obtained after drying.

[0022] Figure 3 This is a schematic diagram of the water-tightness test for catgut. A. Transverse section of tissue; B. Longitudinal section of tissue. Despite undergoing drastic decellularization, the prepared catgut still possesses reliable mechanical strength and sealing ability, meeting the basic functional requirements as a suture.

[0023] Figure 4 This is a schematic diagram of the biocompatibility test results for the sheep gut suture. It confirms that the structural purification of this invention brings about excellent biological effects: after implantation, the decellularized sheep gut exhibits outstanding in vivo biocompatibility. Detailed Implementation

[0024] The present invention will be further described below with reference to embodiments.

[0025] Example 1:

[0026] The following method was used to prepare catgut:

[0027] S1. Pretreatment: Take fresh sheep intestines, clean them, and immerse them in a 1% sodium bicarbonate solution at 4°C for 48 hours; then transfer them to a 20% sodium chloride solution and soak for 15 minutes to degrease them, and rinse with pure water.

[0028] S2. Submucosal stripping: Cut the pre-treated sheep intestines into 50 cm long sections, cut them longitudinally, lay them with the serosa layer facing upwards, scrape off the outer serosa layer, muscle layer and inner mucosa layer, and retain the submucosal layer.

[0029] S3. Decellularization treatment: Immerse the submucosal layer in a 1% sodium dodecyl sulfate solution and shake at 4°C and 120 rpm / min for 48 hours.

[0030] S4. Discard the SDS solution and replace it with a mixed solution of ammonia and Triton X-100 for 24 hours; the mass concentration of ammonia and the mass concentration of Triton X-100 in the mixed solution are both 0.1%.

[0031] S5. Discard the mixed solution and soak the solution in DNase I enzyme preparation at pH 7.3 and 37℃ for 4.5 hours. The concentration of the enzyme preparation is 1.2 mg / mL. Then rinse with ultrapure water for 3 days, changing the water once each in the morning, noon and evening, until the pH and conductivity of the aqueous phase are stable. Then sterilize with 1% (w / w) penicillin-streptomycin solution for 1.2 hours and rinse with sterile water.

[0032] S6. Winding and Dehydration: The decellularized submucosal layer is cut into strips 0.5 cm wide and 50 cm long, and wound into thread with constant tension using a twisting machine. After fixing, it is placed in a 4°C environment for freeze drying to dehydrate and shape, thus obtaining absorbable anti-inflammatory catgut.

[0033] Example 2:

[0034] The following method was used to prepare catgut:

[0035] S1. Pretreatment: Take fresh sheep intestines, clean them, and immerse them in a 0.8% sodium bicarbonate solution at 5°C for 24 hours; then transfer them to a 15% sodium chloride solution for 25 minutes to degrease them, and rinse with pure water.

[0036] S2. Submucosal stripping: Cut the pre-treated sheep intestines into 50 cm long sections, cut them longitudinally, lay them with the serosa layer facing upwards, scrape off the outer serosa layer, muscle layer and inner mucosa layer, and retain the submucosal layer.

[0037] S3. Decellularization treatment: Immerse the submucosal layer in a 0.8% sodium dodecyl sulfate solution and shake at 5°C and 150 rpm / min for 24 hours.

[0038] S4. Discard the SDS solution and replace it with a mixed solution of ammonia and Triton X-100 for 20 hours; the mass concentration of ammonia in the mixed solution is 0.08%, and the mass concentration of Triton X-100 is 0.05%.

[0039] S5. Discard the mixed solution and soak the solution in DNase I enzyme preparation at pH 7.1 and 38℃ for 6 hours. The concentration of the enzyme preparation is 1.3 mg / mL. Then rinse with ultrapure water for 3 days, changing the water once each in the morning, noon and evening, until the pH and conductivity of the aqueous phase are stable. Then sterilize with 0.7% mass concentration of double antibiotic solution for 1.5 hours and rinse with sterile water.

[0040] S6. Winding and Dehydration: The decellularized submucosal layer is cut into strips 0.5 cm wide and 50 cm long, and wound into thread with constant tension using a twisting machine. After fixing, it is placed in a 3°C environment for freeze drying to dehydrate and shape, thus obtaining absorbable anti-inflammatory catgut.

[0041] Example 3:

[0042] The following method was used to prepare catgut:

[0043] S1. Pretreatment: Take fresh sheep intestines, clean them, and immerse them in a 1.5% sodium bicarbonate solution at 3°C ​​for 30 hours; then transfer them to a 25% sodium chloride solution and soak for 10 minutes to degrease them, and rinse with pure water.

[0044] S2. Submucosal stripping: Cut the pre-treated sheep intestines into 50 cm long sections, cut them longitudinally, lay them with the serosa layer facing upwards, scrape off the outer serosa layer, muscle layer and inner mucosa layer, and retain the submucosal layer.

[0045] S3. Decellularization treatment: Immerse the submucosal layer in a 1.5% sodium dodecyl sulfate solution and shake at 3°C ​​and 100 rpm / min for 30 hours.

[0046] S4. Discard the SDS solution and replace it with a mixed solution of ammonia and Triton X-100 for 30 hours; the mass concentration of ammonia in the mixed solution is 0.08%, and the mass concentration of Triton X-100 is 0.09%.

[0047] S5. Discard the mixed solution and soak it in DNase I enzyme preparation at pH 7.4 and 38℃ for 3 hours. The concentration of the enzyme preparation is 1.5 mg / mL. Then rinse with ultrapure water for 3 days, changing the water once each in the morning, noon and evening, until the pH and conductivity of the aqueous phase are stable. Then sterilize with 1.2% mass concentration of double antibiotic solution for 0.8 hours and rinse with sterile water.

[0048] S6. Winding and Dehydration: The decellularized submucosal layer is cut into strips 0.5 cm wide and 50 cm long, and wound into thread with constant tension using a twisting machine. After fixing, it is placed in a 5°C environment for freeze drying to dehydrate and shape, thus obtaining absorbable anti-inflammatory catgut.

[0049] Example 4:

[0050] This example is a control experiment of Example 1, conducted according to the same steps and conditions, using the same batch of raw materials. The difference lies in that the enzyme preparation is a complex enzyme preparation composed of DNase I and endo-β-glucuronidase, wherein the mass ratio of DNase I to endo-β-glucuronidase is 1:0.2. The specific scheme is as follows:

[0051] The following method was used to prepare catgut:

[0052] S1. Pretreatment: Take fresh sheep intestines, clean them, and immerse them in a 1% sodium bicarbonate solution at 4°C for 48 hours; then transfer them to a 20% sodium chloride solution and soak for 15 minutes to degrease them, and rinse with pure water.

[0053] S2. Submucosal stripping: Cut the pre-treated sheep intestines into 50 cm long sections, cut them longitudinally, lay them with the serosa layer facing upwards, scrape off the outer serosa layer, muscle layer and inner mucosa layer, and retain the submucosal layer.

[0054] S3. Decellularization treatment: Immerse the submucosal layer in a 1% sodium dodecyl sulfate solution and shake at 4°C and 120 rpm / min for 48 hours.

[0055] S4. Discard the SDS solution and replace it with a mixed solution of ammonia and Triton X-100 for 24 hours; the mass concentration of ammonia and the mass concentration of Triton X-100 in the mixed solution are both 0.1%.

[0056] S5. Discard the mixed solution and replace it with an enzyme preparation. Soak the solution at pH 7.3 and 37℃ for 4.5 hours. The enzyme preparation is a complex enzyme preparation composed of DNase I and endo-β-glucuronidase, with a mass ratio of DNase I to endo-β-glucuronidase of 1:0.2 and a concentration of 1.2 mg / mL. Then rinse with ultrapure water for 3 days, changing the water once each in the morning, noon and evening, until the pH and conductivity of the aqueous phase are stable. Then sterilize with a 1% (w / w) solution of penicillin-streptomycin for 1.2 hours and rinse with sterile water.

[0057] S6. Winding and Dehydration: The decellularized submucosal layer is cut into strips 0.5 cm wide and 50 cm long, and wound into thread with constant tension using a twisting machine. After fixing, it is placed in a 4°C environment for freeze drying to dehydrate and shape, thus obtaining absorbable anti-inflammatory catgut.

[0058] Comparative Example 1:

[0059] This comparative example serves as a control experiment for Example 1, conducted according to the same steps and conditions, using the same batch of raw materials. The difference lies in the absence of enzyme treatment. The specific protocol is as follows:

[0060] S1. Pretreatment: Take fresh sheep intestines, clean them, and immerse them in a 1% sodium bicarbonate solution at 4°C for 48 hours; then transfer them to a 20% sodium chloride solution and soak for 15 minutes to degrease them, and rinse with pure water.

[0061] S2. Submucosal stripping: Cut the pre-treated sheep intestines into 50 cm long sections, cut them longitudinally, lay them with the serosa layer facing upwards, scrape off the outer serosa layer, muscle layer and inner mucosa layer, and retain the submucosal layer.

[0062] S3. Decellularization treatment: Immerse the submucosal layer in a 1% sodium dodecyl sulfate solution and shake at 4°C and 120 rpm / min for 48 hours.

[0063] S4. Discard the SDS solution and replace it with a mixed solution of ammonia and Triton X-100 for 24 hours; the mass concentration of ammonia and the mass concentration of Triton X-100 in the mixed solution are both 0.1%.

[0064] S5. Discard the mixed solution, then rinse with ultrapure water for 3 days, changing the water once each in the morning, noon and evening, until the pH and conductivity of the aqueous phase are stable. Then sterilize with a 1% (w / w) solution of penicillin-streptomycin for 1.2 hours, and rinse with sterile water.

[0065] S6. Winding and Dehydration: The decellularized submucosal layer is cut into strips 0.5 cm wide and 50 cm long, and wound into thread with constant tension using a twisting machine. After fixing, it is placed in a 4°C environment for freeze drying to dehydrate and shape, thus obtaining absorbable anti-inflammatory catgut.

[0066] Comparative Example 2:

[0067] This comparative example serves as a control experiment for Example 1, conducted according to the same steps and conditions, using the same batch of raw materials. The difference lies in replacing the DNase I enzyme preparation with an endoglucuronidase preparation at the same concentration. The specific protocol is as follows:

[0068] S1. Pretreatment: Take fresh sheep intestines, clean them, and immerse them in a 1% sodium bicarbonate solution at 4°C for 48 hours; then transfer them to a 20% sodium chloride solution and soak for 15 minutes to degrease them, and rinse with pure water.

[0069] S2. Submucosal stripping: Cut the pre-treated sheep intestines into 50 cm long sections, cut them longitudinally, lay them with the serosa layer facing upwards, scrape off the outer serosa layer, muscle layer and inner mucosa layer, and retain the submucosal layer.

[0070] S3. Decellularization treatment: Immerse the submucosal layer in a 1% sodium dodecyl sulfate solution and shake at 4°C and 120 rpm / min for 48 hours.

[0071] S4. Discard the SDS solution and replace it with a mixed solution of ammonia and Triton X-100 for 24 hours; the mass concentration of ammonia and the mass concentration of Triton X-100 in the mixed solution are both 0.1%.

[0072] S5. Discard the mixed solution and soak the solution in an endo-β-glucuronidase preparation at pH 7.3 and 37℃ for 4.5 hours. The concentration of the enzyme preparation is 1.2 mg / mL. Then rinse with ultrapure water for 3 days, changing the water once each in the morning, noon and evening, until the pH and conductivity of the aqueous phase are stable. Then sterilize with a 1% (w / w) solution of penicillin-streptomycin for 1.2 hours and rinse with sterile water.

[0073] S6. Winding and Dehydration: The decellularized submucosal layer is cut into strips 0.5 cm wide and 50 cm long, and wound into thread with constant tension using a twisting machine. After fixing, it is placed in a 4°C environment for freeze drying to dehydrate and shape, thus obtaining absorbable anti-inflammatory catgut.

[0074] Experimental verification:

[0075] The following performance tests were performed on the catgut prepared in Examples 1, 2, 3, and 4, and Comparative Examples 1 and 2:

[0076] I. Detection of residual cell nuclei:

[0077] The cell nuclei in sheep gut samples were stained using the specific binding property of DAPI (4',6-diamidinyl-2-phenylindole) fluorescent dye to double-stranded DNA. The nucleus remnants were observed using a fluorescence microscope, and the nuclear remnant rate was quantitatively calculated using image analysis software.

[0078] 1. Sample preparation:

[0079] Catgut samples from each experimental group were cut into 5×5mm segments; fixed with 4% paraformaldehyde for 24 hours, and washed 3 times with PBS; embedded in paraffin to prepare tissue sections with a thickness of 5μm.

[0080] 2. DAPI staining:

[0081] The slides were treated sequentially with xylene and then with a gradient of ethanol. The DAPI stock solution was diluted to 1 μg / mL with PBS. 100 μL DAPI working solution was added to each slide and incubated in the dark for 15 minutes. The slides were then rinsed with PBS three times for 5 minutes each time.

[0082] 2. Mounting and observation:

[0083] The slides were mounted with anti-quenching mounting medium and observed under a fluorescence microscope with an excitation wavelength of 358 nm and an emission wavelength of 461 nm. Five fields of view (400×) were randomly selected from each sample for photographing.

[0084] 3. Image analysis:

[0085] ImageJ software was used for analysis. A uniform threshold was set, and the number of cell nuclei in each field of view was automatically counted. The cell nucleus density (cells / mm²) was calculated. The cell nucleus residue rate (%) = (cell nucleus density of experimental group / cell nucleus density of non-decellularized control group) × 100%.

[0086] Detection of inflammatory factor expression:

[0087] The inflammatory response characteristics of the material were assessed by co-culturing sheep gut extract with RAW264.7 macrophages and detecting the concentrations of TNF-α and IL-10 in the cell supernatant using ELISA.

[0088] 1. Preparation of sample extract:

[0089] The catgut in each experimental group was added to DMEM complete culture medium at a ratio of 0.1 g / mL and extracted at 37℃ and 5% CO2 for 24 hours; it was then filtered through a 0.22 μm filter membrane for sterilization and stored at 4℃ for later use.

[0090] 2. Cell Culture and Processing:

[0091] RAW264.7 cells were cultured in DMEM complete medium (containing 10% FBS) and seeded in 24-well plates at a density of 1 × 10⁻⁶ cells / well. 5 Cells / well, cultured at 37°C and 5% CO2 for 24 hours until cells adhere.

[0092] 3. Co-culture experiment:

[0093] Discard the original culture medium, add the sample extract, and set up a blank control group (culture medium only) and a positive control group (1 μg / mL LPS). Each group has 6 replicates and is incubated at 37°C and 5% CO2 for 24 hours.

[0094] 4. ELISA test:

[0095] Collect cell supernatant, centrifuge at 3000 rpm for 10 minutes, and follow the instructions for the TNF-α and IL-10 ELISA kit: Antibody coating: overnight at 4°C; Blocking: 1% BSA, incubate at 37°C for 1 hour; Sample addition: standards and test samples, incubate at 37°C for 2 hours; Detection antibody: incubate at 37°C for 1 hour; Enzyme-labeled secondary antibody: incubate at 37°C for 1 hour; Substrate color development: TMB substrate, react in the dark for 15 minutes; Termination: terminate the reaction with 2M H2SO4. Measure the absorbance at 450 nm using a microplate reader, and calculate the factor concentration based on the standard curve.

[0096] III. Animal in vivo healing experiments:

[0097] Male SPF-grade SD rats, weighing 200±20g, were randomly divided into 6 groups of 8 rats each. They were anesthetized intraperitoneally with 1% sodium pentobarbital (40mg / kg). The backs were shaved and disinfected, and full-thickness skin defects of 1.5cm in diameter were created symmetrically on both sides of the spine. The experimental groups were sutured using catgut sutures from Examples 1 and 4, Comparative Examples 1 and 2, respectively. Postoperatively, the rats were housed separately with free access to food. Immunohistochemical results were tested 7 days postoperatively. Figure 1 .

[0098] Table 1 Comparison of residual nuclei and expression of inflammatory factors in sheep gut cells among different groups

[0099]

[0100] Based on the test results in Table 1 Figure 1 Immunohistochemical results of sutures made from catgut in SD rats showed that the catgut used in Examples 1 to 4 was significantly superior to the control group (Example 1) in terms of residual cell nuclei, expression of pro-inflammatory TNF-α, expression of anti-inflammatory IL-10, and immunohistochemical results, demonstrating excellent anti-inflammatory effects. The inventors believe this is because while SDS can efficiently lyse cells and separate DNA-protein linkages, its ability to degrade long-chain DNA is limited. Therefore, ammonia and Triton were used to further remove cell debris and lipids. The subsequent use of the enzyme preparation of this invention can specifically hydrolyze the residual DNA chains into oligonucleotides or small nucleotide molecules, making them easily washed away, thereby more thoroughly eliminating DNA-induced immunogenicity. In animal implantation experiments, this resulted in milder inflammatory responses and faster wound healing.

[0101] Meanwhile, in Comparative Example 2, the use of endo-β-glucuronidase alone showed almost no significant improvement compared to Comparative Example 1. However, when a combined enzyme preparation consisting of DNase I and endo-β-glucuronidase was used at the same enzyme concentration, the expression of the pro-inflammatory factor TNF-α and the anti-inflammatory factor IL-10 in Example 4 showed significant improvement compared to Example 1. Figure 1 Immunohistochemical results also confirmed this effect (achieving faster wound repair, milder inflammatory response, and significantly higher healing quality). It is evident that DNase I and endo-β-glucuronidase in the compound enzyme preparation used in this invention exhibit a significant synergistic effect in enhancing the anti-inflammatory properties of sheep catgut.

Claims

1. A method for manufacturing absorbable anti-inflammatory catgut, characterized in that, Includes the following steps: S1. Pretreatment: Take fresh sheep intestines, clean them, and immerse them in a 0.5% to 1.5% sodium bicarbonate solution at 3°C ​​to 5°C for more than 24 hours; then transfer them to a 10% to 30% sodium chloride solution and soak for 10 to 25 minutes to degrease them, and rinse with pure water. S2. Submucosal stripping: Cut the pre-treated sheep intestines into 30-70 cm long segments, cut them longitudinally, lay them with the serosa layer facing upwards, scrape off the outer serosa layer, muscle layer and inner mucosa layer, and retain the submucosal layer. S3. Decellularization treatment: Immerse the submucosal layer in a 0.5%–1.5% sodium dodecyl sulfate solution and shake at 3°C–5°C and 100–150 rpm for at least 24 hours. S4. Discard the SDS solution and replace it with a mixed solution of ammonia and Triton X-100 for 16–30 hours; the mass concentration of ammonia in the mixed solution is 0.08%–0.12%, and the mass concentration of Triton X-100 is 0.05%–0.15%. S5. Discard the mixed solution and soak the sample in the enzyme preparation for 3–6 hours; then rinse with ultrapure water for at least 2 days, followed by sterilization with a 0.7%–1.2% (w / w) double-antibiotic solution for 0.8–1.5 hours, and rinse with sterile water; the enzyme preparation is a complex enzyme preparation composed of DNase I and endoglucuronidase, with a concentration of 0.5–2 mg / mL; the mass ratio of DNase I to endoglucuronidase in the complex enzyme preparation is 1:0.01–0.4; the enzyme preparation soaking treatment is carried out at a pH of 7.0–7.5 and a temperature of 36–38℃; S6. Winding and Dehydration: The decellularized submucosa is cut into strips 0.3-0.7 cm wide and 30-70 cm long. The strips are wound into threads with constant tension using a twisting machine. After fixing, the threads are placed in an environment of 3℃-5℃ for dehydration and shaping to obtain absorbable anti-inflammatory catgut.

2. The method for producing absorbable anti-inflammatory catgut according to claim 1, characterized in that: During the ultrapure water rinsing process in step S5, the water is changed once each in the morning, noon, and evening until the pH and conductivity of the aqueous phase stabilize.

3. The method for producing absorbable anti-inflammatory catgut according to claim 1, characterized in that: In step S6, dehydration is performed by natural air drying or freeze drying.

4. An absorbable anti-inflammatory catgut prepared by the method described in any one of claims 1 to 3.

5. The absorbable anti-inflammatory catgut according to claim 4, characterized in that: The residual rate of the sheep gut cells was less than 5%. Within 7 days of implantation, the expression level of the pro-inflammatory factor TNF-α decreased by more than 40%, and the expression level of the anti-inflammatory factor IL-10 increased by more than 50%.

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