An absorbable artificial spider silk suture and its preparation method

Abstract

This invention discloses an absorbable artificial spider silk suture and its preparation method. It comprises the following raw material components in parts by weight: 10-15 parts polymer material, 80-180 parts solvent, 0.05-0.15 parts type I collagen, 8-12 parts acetic acid solution, and 0.05-0.25 parts antibacterial agent. The twisting process used in this invention can increase the mechanical strength of the fiber by up to 150%, while improving the fiber's fatigue resistance. The addition of a collagen shell enhances the binding with the collagen gel, ensuring biological function while facilitating stress distribution at the splicing interface.

Description

Technical Field

[0001] This invention belongs to the field of medical textile technology, specifically relating to an absorbable artificial spider silk suture and its preparation method. Background Technology

[0002] The development of biocompatible sutures initially stemmed from the dual limitations of traditional materials in terms of mechanical properties and biocompatibility. Early synthetic sutures, such as nylon and polyester, while possessing high tensile strength (some reaching 70-80 MPa), were non-degradable materials. Their long-term presence in the body could easily trigger chronic inflammation or foreign body reactions, requiring secondary surgery for suture removal, increasing patient suffering and infection risks. While natural materials like catgut are biodegradable, they suffer from insufficient mechanical strength (tensile strength typically below 15 MPa) and unstable degradation rates. They often lose support before tissue has fully healed, or degrade too rapidly, producing acidic metabolites that cause local inflammation. These challenges directly spurred the exploration of novel absorbable fibers.

[0003] PLLA (polylactic acid L-L) is a biodegradable polymer material widely used in medical sutures, tissue engineering scaffolds, and other fields due to its non-toxicity, biodegradability, and excellent mechanical properties. However, PLLA itself is prone to problems such as insufficient crystallinity and accelerated thermal degradation during processing, making it difficult for the tensile strength and elongation at break of the fibers to meet the requirements of high-load applications. Currently, the mainstream methods to improve mechanical properties include: material modification, such as blending linear high molecular weight polylactic acid or polylactic acid copolymers with biodegradable crosslinking agents (CN103709386B); structural improvement, such as the matrix material being a three-dimensional network structure of crosslinked biodegradable polymer material (CN106147164A). Improving cell compatibility and toxicity can be approached from the perspective of surface modification, such as the method for preparing superhydrophobic polylactic acid fibers disclosed in this invention (CN109234834B); and structural characteristics, such as the method for preparing porous polylactic acid biomembranes disclosed in this invention (CN105694073A).

[0004] Decellularized matrix or collagen provides a scaffold, promoting autologous tissue ingrowth and resulting in a low long-term recurrence rate. The degradation of composite patches is controllable, with some materials gradually absorbed after the support period, avoiding long-term foreign collagen residue. While the invention aims to provide a collagen fiber membrane with sufficient strength for use as a cell culture substrate and regenerative medicine scaffold material (EP2644692B1), a simple collagen structure implies a faster degradation rate and lower mechanical strength, making it suitable only for tissue engineering with no or minimal stress requirements.

[0005] The above methods have improved the mechanical strength or biocompatibility of absorbable fibers to some extent, but no one has yet achieved the integration of multi-dimensional performance. Therefore, this invention addresses this gap by developing an artificial spider silk suture based on high-speed electrospinning and co-solution interface effect, which has good mechanical properties, excellent biocompatibility, and a segmented degradation curve. Summary of the Invention

[0006] The purpose of this invention is to provide an absorbable artificial spider silk suture and its preparation method.

[0007] An absorbable artificial spider silk suture comprises the following raw material components in parts by weight: 10-15 parts of polymer material, 80-180 parts of solvent, 0.05-0.15 parts of type I collagen, 8-12 parts of acetic acid solution, and 0.05-0.25 parts of antibacterial agent.

[0008] The polymeric material is a mixture of poly-L-lactic acid and polyglycolic acid-trimethylene carbonate copolymer in a mass ratio of 1:1; the molecular weight of the poly-L-lactic acid is 200,000-400,000 Da, and the molecular weight of the polyglycolic acid-trimethylene carbonate copolymer is 100,000-200,000 Da.

[0009] The solvent is dichloromethane and / or N,N-dimethylformamide.

[0010] The molecular weight of the type I collagen is 200,000-400,000 Da.

[0011] The antibacterial agent is a mixed antibacterial agent consisting of histamine 5 and human α-defensin 5 mixed in a mass ratio of 1:1.

[0012] The antibacterial agent is a mixed antibacterial agent consisting of proanthocyanidins and tannic acid in a mass ratio of 3:1.

[0013] The mass concentration of the acetic acid solution is 2-4%.

[0014] The method for preparing the absorbable artificial spider silk suture is carried out according to the following steps: (1) Dissolve 10-15g of polymer material in 100mL of solvent, stir magnetically for 3-5h, add 0.05-0.25g of antibacterial agent, stir and mix evenly to obtain core spinning solution; (2) Dissolve 0.05-0.15g of type I collagen in 8-12mL of 2-4% acetic acid solution, and shear and stir for 4-8h to obtain collagen gel; (3) Take 50 mL of the collagen gel prepared in step (2) and mix it with 100 mL of the core spinning solution prepared in step (1). Let it stand until the solution separates into layers again. Then, remove the lower layer of viscous solution to obtain the middle layer spinning solution. (4) Use two 5 ml syringes to draw 0.5 ml of core spinning solution and 0.5 ml of intermediate spinning solution; connect the core spinning solution syringe to the center of the coaxial spinning needle, and connect the intermediate spinning solution syringe to the outer channel. Set the advance speed to 0.2-0.4 mm / min; adjust the speed of the high-speed receiving roller to 2000-4000 rpm and the distance between the spinning needle and the needle to 10-20 cm. Set the voltage to -1+18 kV. After adjusting the parameters, start spinning to obtain a whole fiber film and remove it. (5) Cut the whole fiber film into 2-6 strips. Cut each fiber strip at a 45° angle on both sides to form an eccentric triangle. Continue to overlap the fiber strips at half a length interval and align the cuts. Splice the fibers continuously by twisting them in a Z-shaped twisting direction, with a twist of 0.4-0.6 turns / cm and a pre-stretch force of 20-40g, and fix them overnight. (6) After the fiber bundle is completely dry, immerse the fiber bundle in collagen gel for 2-4 hours, take it out and freeze dry to obtain absorbable artificial spider silk suture.

[0015] The beneficial effects of this invention are as follows: The twisting process used in this invention can increase the mechanical strength of the fiber by up to 150%, while improving the fiber's fatigue resistance. The addition of a collagen shell can enhance the binding with the collagen gel, which is beneficial to the stress distribution at the splicing interface while ensuring biological function. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of fiber twisting.

[0017] Figure 2 This is a picture of a twisted fiber.

[0018] Figure 3 This is a schematic diagram of fiber splicing.

[0019] Figure 4 Electron micrographs of PLLA and PLLA-collagen high-speed electrospun thin films.

[0020] Figure 5 SEM image of the twisted fiber. Detailed Implementation

[0021] To facilitate understanding of the present invention, a more comprehensive description will be given below. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the present invention. Example 1

[0022] An absorbable artificial spider silk suture comprises the following raw material components in parts by weight: 12.5g of polymer material, 100mL of dichloromethane, 0.1g of type I collagen, 10mL of 3% acetic acid solution, and 0.2g of antibacterial agent. The polymer material is a mixture of poly-L-lactic acid and polyglycolic acid-trimethylene carbonate copolymer in a 1:1 mass ratio; the molecular weight of the poly-L-lactic acid is 300,000 Da, and the molecular weight of the polyglycolic acid-trimethylene carbonate copolymer is 150,000 Da. The molecular weight of the type I collagen is 300,000 Da. The antibacterial agent is a mixed antibacterial agent of proanthocyanidins and tannic acid in a 3:1 mass ratio.

[0023] The method for preparing the absorbable artificial spider silk suture is carried out according to the following steps: (1) Dissolve 12.5g of polymer material in 100mL of solvent, stir magnetically for 4h, add 0.2g of antibacterial agent, stir and mix evenly to obtain core spinning solution; (2) Dissolve 0.1g of type I collagen in 10mL of 3% acetic acid solution, and shear and stir for 6h to obtain collagen gel; (3) Take 50 mL of the collagen gel prepared in step (2) and mix it with 100 mL of the core spinning solution prepared in step (1). Let it stand until the solution separates into layers again. Then, remove the lower layer of viscous solution to obtain the middle layer spinning solution. (4) Use two 5 ml syringes to draw 0.5 ml of core spinning solution and 0.5 ml of intermediate spinning solution; connect the core spinning solution syringe to the center of the coaxial spinning needle, and connect the intermediate spinning solution syringe to the outer channel. Set the advance speed to 0.3 mm / min; adjust the speed of the high-speed receiving roller to 3000 rpm and the distance between the spinning needle to 15 cm. Set the voltage to -1 +18 kV. After adjusting the parameters, start spinning to obtain a whole fiber film and remove it. (5) Cut the whole fiber film into 4 strips. Cut each fiber strip at a 45° angle on both sides to form an eccentric triangle. Continue to overlap the fiber strips at half a length interval and align the cuts. Splice the fibers continuously by twisting them in a Z-shaped twisting direction, with a twist of 0.5 turns / cm and a pre-stretching force of 30g, and fix them overnight. (6) After the fiber bundle is completely dry, immerse the fiber bundle in collagen gel for 3 hours, remove it and freeze-dry it to obtain absorbable artificial spider silk sutures. Figure 1-3 ). Example 2

[0024] An absorbable artificial spider silk suture comprises the following raw material components in parts by weight: 12g of polymer material, 100mL of N,N-dimethylformamide, 0.08g of type I collagen, 8mL of 3% acetic acid solution, and 0.15g of antibacterial agent. The polymer material is a mixture of poly-L-lactic acid and polyglycolic acid-trimethylene carbonate copolymer in a 1:1 mass ratio; the molecular weight of the poly-L-lactic acid is 250,000 Da, and the molecular weight of the polyglycolic acid-trimethylene carbonate copolymer is 150,000 Da. The molecular weight of the type I collagen is 250,000 Da. The antibacterial agent is a mixed antibacterial agent of histamine 5 and human α-defensin 5 in a 1:1 mass ratio.

[0025] The method for preparing the absorbable artificial spider silk suture is carried out according to the following steps: (1) Dissolve 12g of polymer material in 100mL of N,N-dimethylformamide, stir magnetically for 3h, add 0.15g of antibacterial agent, stir and mix evenly to obtain the core spinning solution; (2) Dissolve 0.08g of type I collagen in 8mL of 3% acetic acid solution, and shear and stir for 5h to obtain collagen gel; (3) Take 50 mL of the collagen gel prepared in step (2) and mix it with 100 mL of the core spinning solution prepared in step (1). Let it stand until the solution separates into layers again. Then, remove the lower layer of viscous solution to obtain the middle layer spinning solution. (4) Use two 5 ml syringes to draw 0.5 ml of core spinning solution and 0.5 ml of intermediate spinning solution; connect the core spinning solution syringe to the center of the coaxial spinning needle, and connect the intermediate spinning solution syringe to the outer channel. Set the advance speed to 0.25 mm / min; adjust the speed of the high-speed receiving roller to 2500 rpm and the distance between the spinning needle to 12 cm. Set the voltage to -1 +18 kV. After adjusting the parameters, start spinning to obtain a whole fiber film and remove it. (5) Cut the whole fiber film into 3 strips. Cut each fiber strip at a 45° angle on both sides to form an eccentric triangle. Continue to overlap the fiber strips at half a length interval and align the cuts. Splice the fibers continuously by twisting them in a Z-shaped twisting direction, with a twist of 0.45 turns / cm and a pre-stretching force of 25g, and fix them overnight. (6) After the fiber bundle is completely dry, immerse the fiber bundle in collagen gel for 2 hours, take it out and freeze dry to obtain absorbable artificial spider silk suture. Example 3

[0026] An absorbable artificial spider silk suture comprises the following raw material components in parts by weight: 14g of polymer material, 100mL of dichloromethane, 0.15g of type I collagen, 12mL of 3% acetic acid solution, and 0.25g of antibacterial agent. The polymer material is a mixture of poly-L-lactic acid and polyglycolic acid-trimethylene carbonate copolymer in a 1:1 mass ratio; the molecular weight of the poly-L-lactic acid is 35,000 Da, and the molecular weight of the polyglycolic acid-trimethylene carbonate copolymer is 180,000 Da. The molecular weight of the type I collagen is 350,000 Da. The antibacterial agent is a mixed antibacterial agent of proanthocyanidins and tannic acid in a 3:1 mass ratio.

[0027] The method for preparing the absorbable artificial spider silk suture is carried out according to the following steps: (1) Dissolve 14g of polymer material in 100mL of dichloromethane, stir magnetically for 5h, add 0.25g of antibacterial agent, stir and mix evenly to obtain the core spinning solution; (2) Dissolve 0.15g of type I collagen in 12mL of 3% acetic acid solution, and shear and stir for 8h to obtain collagen gel; (3) Take 50 mL of the collagen gel prepared in step (2) and mix it with 100 mL of the core spinning solution prepared in step (1). Let it stand until the solution separates into layers again. Then, remove the lower layer of viscous solution to obtain the middle layer spinning solution. (4) Use two 5 ml syringes to draw 0.5 ml of core spinning solution and 0.5 ml of intermediate spinning solution; connect the core spinning solution syringe to the center of the coaxial spinning needle, and connect the intermediate spinning solution syringe to the outer channel. Set the advance speed to 0.35 mm / min; adjust the speed of the high-speed receiving roller to 3500 rpm and the distance between the spinning needle and the needle to 18 cm. Set the voltage to -1 +18 kV. After adjusting the parameters, start spinning to obtain a whole fiber film and remove it. (5) Cut the whole fiber film into 5 strips. Cut each fiber strip at a 45° angle on both sides to form an eccentric triangle. Continue to overlap the fiber strips at half a length interval and align the cuts. Splice the fibers continuously by twisting them in a Z-shaped twisting direction, with a twist of 0.5 turns / cm and a pre-stretching force of 35g, and fix them overnight. (6) After the fiber bundle is completely dry, immerse the fiber bundle in collagen gel for 4 hours, take it out and freeze dry to obtain absorbable artificial spider silk suture.

[0028] Comparative Example 1 An absorbable artificial spider silk suture comprises the following raw material components in parts by weight: 12.5g poly-L-lactic acid, 100mL dichloromethane, 0.1g type I collagen, 10mL 3% acetic acid solution, and 0.2g antibacterial agent. The poly-L-lactic acid has a molecular weight of 300,000 Da. The type I collagen has a molecular weight of 300,000 Da. The antibacterial agent is a mixture of proanthocyanidins and tannic acid in a mass ratio of 3:1.

[0029] The method for preparing the absorbable artificial spider silk suture is carried out according to the following steps: (1) Dissolve 12.5g of poly-L-lactic acid in 100mL of solvent, stir magnetically for 4h, add 0.2g of antibacterial agent, stir and mix evenly to obtain the core spinning solution; (2) Dissolve 0.1g of type I collagen in 10mL of 3% acetic acid solution, and shear and stir for 6h to obtain collagen gel; (3) Take 50 mL of the collagen gel prepared in step (2) and mix it with 100 mL of the core spinning solution prepared in step (1). Let it stand until the solution separates into layers again. Then, remove the lower layer of viscous solution to obtain the middle layer spinning solution. (4) Use two 5 ml syringes to draw 0.5 ml of core spinning solution and 0.5 ml of intermediate spinning solution; connect the core spinning solution syringe to the center of the coaxial spinning needle, and connect the intermediate spinning solution syringe to the outer channel. Set the advance speed to 0.3 mm / min; adjust the speed of the high-speed receiving roller to 3000 rpm and the distance between the spinning needle to 15 cm. Set the voltage to -1 +18 kV. After adjusting the parameters, start spinning to obtain a whole fiber film and remove it. (5) Cut the whole fiber film into 4 strips. Cut each fiber strip at a 45° angle on both sides to form an eccentric triangle. Continue to overlap the fiber strips at half a length interval and align the cuts. Splice the fibers continuously by twisting them in a Z-shaped twisting direction, with a twist of 0.5 turns / cm and a pre-stretching force of 30g, and fix them overnight. (6) After the fiber bundle is completely dry, immerse the fiber bundle in collagen gel for 3 hours, take it out and freeze dry to obtain absorbable artificial spider silk suture.

[0030] Comparative Example 2 An absorbable artificial spider silk suture comprises the following raw material components in parts by weight: 12.5g of polyglycolic acid-trimethylene carbonate copolymer, 100mL of dichloromethane, 0.1g of type I collagen, 10mL of 3% acetic acid solution, and 0.2g of antibacterial agent. The polyglycolic acid-trimethylene carbonate copolymer has a molecular weight of 150,000 Da. The type I collagen has a molecular weight of 300,000 Da. The antibacterial agent is a mixture of proanthocyanidins and tannic acid in a mass ratio of 3:1.

[0031] The method for preparing the absorbable artificial spider silk suture is carried out according to the following steps: (1) Dissolve 12.5g of polyglycolic acid-trimethylene carbonate copolymer in 100mL of solvent, stir magnetically for 4h, add 0.2g of antibacterial agent, stir and mix evenly to obtain core spinning solution; (2) Dissolve 0.1g of type I collagen in 10mL of 3% acetic acid solution, and shear and stir for 6h to obtain collagen gel; (3) Take 50 mL of the collagen gel prepared in step (2) and mix it with 100 mL of the core spinning solution prepared in step (1). Let it stand until the solution separates into layers again. Then, remove the lower layer of viscous solution to obtain the middle layer spinning solution. (4) Use two 5 ml syringes to draw 0.5 ml of core spinning solution and 0.5 ml of intermediate spinning solution; connect the core spinning solution syringe to the center of the coaxial spinning needle, and connect the intermediate spinning solution syringe to the outer channel. Set the advance speed to 0.3 mm / min; adjust the speed of the high-speed receiving roller to 3000 rpm and the distance between the spinning needle to 15 cm. Set the voltage to -1 +18 kV. After adjusting the parameters, start spinning to obtain a whole fiber film and remove it. (5) Cut the whole fiber film into 4 strips. Cut each fiber strip at a 45° angle on both sides to form an eccentric triangle. Continue to overlap the fiber strips at half a length interval and align the cuts. Splice the fibers continuously by twisting them in a Z-shaped twisting direction, with a twist of 0.5 turns / cm and a pre-stretching force of 30g, and fix them overnight. (6) After the fiber bundle is completely dry, immerse the fiber bundle in collagen gel for 3 hours, take it out and freeze dry to obtain absorbable artificial spider silk suture.

[0032] Comparative Example 3 An absorbable artificial spider silk suture comprises the following raw material components in parts by weight: 12.5g of polymer material, 100mL of dichloromethane, 0.1g of type I collagen, 10mL of 3% acetic acid solution, and 0.2g of proanthocyanidins. The polymer material is a mixture of poly-L-lactic acid and polyglycolic acid-trimethylene carbonate copolymer in a 1:1 mass ratio; the molecular weight of the poly-L-lactic acid is 300,000 Da, and the molecular weight of the polyglycolic acid-trimethylene carbonate copolymer is 150,000 Da. The molecular weight of the type I collagen is 300,000 Da.

[0033] The method for preparing the absorbable artificial spider silk suture is carried out according to the following steps: (1) Dissolve 12.5g of polymer material in 100mL of solvent, stir magnetically for 4h, add 0.2g of proanthocyanidins, stir and mix evenly to obtain the core spinning solution; (2) Dissolve 0.1g of type I collagen in 10mL of 3% acetic acid solution, and shear and stir for 6h to obtain collagen gel; (3) Take 50 mL of the collagen gel prepared in step (2) and mix it with 100 mL of the core spinning solution prepared in step (1). Let it stand until the solution separates into layers again. Then, remove the lower layer of viscous solution to obtain the middle layer spinning solution. (4) Use two 5 ml syringes to draw 0.5 ml of core spinning solution and 0.5 ml of intermediate spinning solution; connect the core spinning solution syringe to the center of the coaxial spinning needle, and connect the intermediate spinning solution syringe to the outer channel. Set the advance speed to 0.3 mm / min; adjust the speed of the high-speed receiving roller to 3000 rpm and the distance between the spinning needle to 15 cm. Set the voltage to -1 +18 kV. After adjusting the parameters, start spinning to obtain a whole fiber film and remove it. (5) Cut the whole fiber film into 4 strips. Cut each fiber strip at a 45° angle on both sides to form an eccentric triangle. Continue to overlap the fiber strips at half a length interval and align the cuts. Splice the fibers continuously by twisting them in a Z-shaped twisting direction, with a twist of 0.5 turns / cm and a pre-stretching force of 30g, and fix them overnight. (6) After the fiber bundle is completely dry, immerse the fiber bundle in collagen gel for 3 hours, take it out and freeze dry to obtain absorbable artificial spider silk suture.

[0034] Comparative Example 4 An absorbable artificial spider silk suture comprises the following raw material components in parts by weight: 12.5g of polymer material, 100mL of dichloromethane, 0.1g of type I collagen, 10mL of 3% acetic acid solution, and 0.2g of tannic acid. The polymer material is a mixture of poly-L-lactic acid and polyglycolic acid-trimethylene carbonate copolymer in a 1:1 mass ratio; the molecular weight of the poly-L-lactic acid is 300,000 Da, and the molecular weight of the polyglycolic acid-trimethylene carbonate copolymer is 150,000 Da. The molecular weight of the type I collagen is 300,000 Da. The preparation method of the absorbable artificial spider silk suture is carried out according to the following steps: (1) Dissolve 12.5g of polymer material in 100mL of solvent, stir magnetically for 4h, add 0.2g of tannic acid, stir and mix evenly to obtain the core spinning solution; (2) Dissolve 0.1g of type I collagen in 10mL of 3% acetic acid solution, and shear and stir for 6h to obtain collagen gel; (3) Take 50 mL of the collagen gel prepared in step (2) and mix it with 100 mL of the core spinning solution prepared in step (1). Let it stand until the solution separates into layers again. Then, remove the lower layer of viscous solution to obtain the middle layer spinning solution. (4) Use two 5 ml syringes to draw 0.5 ml of core spinning solution and 0.5 ml of intermediate spinning solution; connect the core spinning solution syringe to the center of the coaxial spinning needle, and connect the intermediate spinning solution syringe to the outer channel. Set the advance speed to 0.3 mm / min; adjust the speed of the high-speed receiving roller to 3000 rpm and the distance between the spinning needle to 15 cm. Set the voltage to -1 +18 kV. After adjusting the parameters, start spinning to obtain a whole fiber film and remove it. (5) Cut the whole fiber film into 4 strips. Cut each fiber strip at a 45° angle on both sides to form an eccentric triangle. Continue to overlap the fiber strips at half a length interval and align the cuts. Splice the fibers continuously by twisting them in a Z-shaped twisting direction, with a twist of 0.5 turns / cm and a pre-stretching force of 30g, and fix them overnight. (6) After the fiber bundle is completely dry, immerse the fiber bundle in collagen gel for 3 hours, take it out and freeze dry to obtain absorbable artificial spider silk suture.

[0035] Comparative Example 5 An absorbable artificial spider silk suture comprises the following raw material components in parts by weight: 12g of polymer material, 100mL of N,N-dimethylformamide, 0.08g of type I collagen, 8mL of 3% acetic acid solution, and 0.15g of histamine 5. The polymer material is a mixture of poly-L-lactic acid and polyglycolic acid-trimethylene carbonate copolymer in a 1:1 mass ratio; the molecular weight of the poly-L-lactic acid is 250,000 Da, and the molecular weight of the polyglycolic acid-trimethylene carbonate copolymer is 150,000 Da. The molecular weight of the type I collagen is 250,000 Da.

[0036] The method for preparing the absorbable artificial spider silk suture is carried out according to the following steps: (1) Dissolve 12g of polymer material in 100mL of N,N-dimethylformamide, stir magnetically for 3h, add 0.15g of histamine 5, stir and mix evenly to obtain the core spinning solution; (2) Dissolve 0.08g of type I collagen in 8mL of 3% acetic acid solution, and shear and stir for 5h to obtain collagen gel; (3) Take 50 mL of the collagen gel prepared in step (2) and mix it with 100 mL of the core spinning solution prepared in step (1). Let it stand until the solution separates into layers again. Then, remove the lower layer of viscous solution to obtain the middle layer spinning solution. (4) Use two 5 ml syringes to draw 0.5 ml of core spinning solution and 0.5 ml of intermediate spinning solution; connect the core spinning solution syringe to the center of the coaxial spinning needle, and connect the intermediate spinning solution syringe to the outer channel. Set the advance speed to 0.25 mm / min; adjust the speed of the high-speed receiving roller to 2500 rpm and the distance between the spinning needle to 12 cm. Set the voltage to -1 +18 kV. After adjusting the parameters, start spinning to obtain a whole fiber film and remove it. (5) Cut the whole fiber film into 3 strips. Cut each fiber strip at a 45° angle on both sides to form an eccentric triangle. Continue to overlap the fiber strips at half a length interval and align the cuts. Splice the fibers continuously by twisting them in a Z-shaped twisting direction, with a twist of 0.45 turns / cm and a pre-stretching force of 25g, and fix them overnight. (6) After the fiber bundle is completely dry, immerse the fiber bundle in collagen gel for 2 hours, take it out and freeze dry to obtain absorbable artificial spider silk suture.

[0037] Comparative Example 6 An absorbable artificial spider silk suture comprises the following raw material components in parts by weight: 12g of polymer material, 100mL of N,N-dimethylformamide, 0.08g of type I collagen, 8mL of 3% acetic acid solution, and 0.15g of human α-defensin 5. The polymer material is a mixture of poly-L-lactic acid and polyglycolic acid-trimethylene carbonate copolymer in a 1:1 mass ratio; the molecular weight of the poly-L-lactic acid is 250,000 Da, and the molecular weight of the polyglycolic acid-trimethylene carbonate copolymer is 150,000 Da. The molecular weight of the type I collagen is 250,000 Da.

[0038] The method for preparing the absorbable artificial spider silk suture is carried out according to the following steps: (1) Dissolve 12g of polymer material in 100mL of N,N-dimethylformamide, stir magnetically for 3h, add 0.15g of human α-defensin 5, stir and mix evenly to obtain the core spinning solution; (2) Dissolve 0.08g of type I collagen in 8mL of 3% acetic acid solution, and shear and stir for 5h to obtain collagen gel; (3) Take 50 mL of the collagen gel prepared in step (2) and mix it with 100 mL of the core spinning solution prepared in step (1). Let it stand until the solution separates into layers again. Then, remove the lower layer of viscous solution to obtain the middle layer spinning solution. (4) Use two 5 ml syringes to draw 0.5 ml of core spinning solution and 0.5 ml of intermediate spinning solution; connect the core spinning solution syringe to the center of the coaxial spinning needle, and connect the intermediate spinning solution syringe to the outer channel. Set the advance speed to 0.25 mm / min; adjust the speed of the high-speed receiving roller to 2500 rpm and the distance between the spinning needle to 12 cm. Set the voltage to -1 +18 kV. After adjusting the parameters, start spinning to obtain a whole fiber film and remove it. (5) Cut the whole fiber film into 3 strips. Cut each fiber strip at a 45° angle on both sides to form an eccentric triangle. Continue to overlap the fiber strips at half a length interval and align the cuts. Splice the fibers continuously by twisting them in a Z-shaped twisting direction, with a twist of 0.45 turns / cm and a pre-stretching force of 25g, and fix them overnight. (6) After the fiber bundle is completely dry, immerse the fiber bundle in collagen gel for 2 hours, take it out and freeze dry to obtain absorbable artificial spider silk suture.

[0039] Experimental example: Mechanics Experiment: The PLLA-collagen high-speed electrospun film and PLLA film prepared in Example 1 were observed under an electron microscope, as shown... Figure 4-5 As shown, Figure 4 and Figure 5 The images show the microstructures of PLLA high-speed electrospinning and coaxial spinning with an intermediate layer, respectively. The surface protrusions are PLLA wrinkles containing collagen.

[0040] The breaking strength and breaking strain of the artificial spider silk sutures prepared in Examples 1-3 and Comparative Examples 1-2 were determined. The experimental results were statistically analyzed using SPSS 24.0 software. Quantitative data were expressed as x ± (mean ± standard deviation). The Kolmogorov-Smirnov test was used to test the normality of the data. For normally distributed data, the t-test was used to compare the differences in means between two groups, with P < 0.05 considered statistically significant. The results are shown in Table 1. Table 1

[0041] Note: * indicates that compared with Example 1 group, P<0.05.

[0042] Sterilization experiment: (1) Experimental preparation and strain activation First, the standard strain of Staphylococcus aureus (ATCC6538) was activated and preserved from glycerol tubes or slant agar at -80℃. Under aseptic conditions, the strain was streaked onto trypsin-soybean agar (TSA) plates and incubated upside down in a 37℃ incubator for 20 hours. Next, a single colony with good morphology was picked and inoculated into a sterile test tube containing 5 mL of trypsin-soybean broth (TSB). The tube was then incubated at 37℃ and 200 rpm in a shaker for 14 hours to allow it to reach the late logarithmic growth stage, at which point the bacterial concentration was approximately 10⁻⁶. 8 -10 9 CFU / mL provides a high concentration of bacterial strain for subsequent experiments.

[0043] (2) Preparation of bacterial suspension and pretreatment of materials Take the cultured bacterial suspension and centrifuge at 4°C and 8000 rpm for 5 min, discarding the supernatant (culture medium rich in metabolic waste). Then, resuspend the bacterial pellet in sterile phosphate-buffered saline (PBS, pH=7.4) and centrifuge again. Repeat this step twice to thoroughly remove residual culture medium and avoid interference with subsequent bactericidal efficacy evaluation. Finally, resuspend the washed bacterial pellet in PBS and use a spectrophotometer (OD) to measure the bacterial concentration. 600 Alternatively, the bacterial suspension can be precisely adjusted to a working concentration of 1×10⁻⁶ using the serial dilution plate count method. 6 CFU / mL. Meanwhile, the antibacterial material to be tested was cut into uniform sizes (e.g., 5 mm diameter discs) and then subjected to strict sterilization by immersion in 75% ethanol and UV irradiation (30 min / side) for later use.

[0044] (3) Co-culture and sonication Experimental and control groups were set up in sterile 24-well cell culture plates. 500 μL of the prepared bacterial suspension (1×10⁻⁶) was added to each well of the experimental group. 6 The positive control group received 500 μL of bacterial suspension (CFU / mL) and one sterile culture medium. The positive control group received only 500 μL of bacterial suspension (no culture medium). The culture medium control group received 500 μL of PBS and one sterile culture medium (to observe whether the culture medium itself dissolves interfering substances). The culture plates were sealed and placed in a pre-set ultrasonic bath (or probe-type ultrasonic instrument) for treatment. Recommended ultrasonic parameters were: frequency 40 kHz, power density 150 mW / cm², 10 min. The entire treatment process should be carried out in an ice-water bath to counteract the potential impact of the heat generated by ultrasound on bacterial survival. A corresponding control group was set up at each time point.

[0045] (4) Sample collection and plate counting Immediately after each preset time point (6, 12, 24), aspirate 100 μL of bacterial suspension from the corresponding well. If the bacterial concentration is high, perform a 10-fold serial dilution with PBS (e.g., 10¹, 10², 10³ times). Then, take 100 μL from each dilution and spread it evenly on a TSA plate. It is recommended to set up three replicates for each sample or dilution to reduce error. Place all spread plates upright in a 37°C incubator and incubate for 20 hours. Count the colonies after they are clearly visible.

[0046] (5) Data analysis and performance calculation For counting, plates with colony counts between 30 and 300 were selected for calculation. The actual viable bacterial concentration (CFU / mL) of each sample after ultrasonic treatment was calculated by back-calculating the dilution. The sterilization rate was calculated using the formula: Sterilization rate (%) = [(Average CFU of positive control group - Average CFU of experimental group) / Average CFU of positive control group] × 100%.

[0047] The experimental results were statistically analyzed using SPSS 24.0 software. Quantitative data were expressed as mean ± standard deviation (x ± √2). The Kolmogorov-Smirnov test was used to test the normality of the data. For normally distributed data, the t-test was used to compare the differences in means between two groups, with P < 0.05 considered statistically significant. The measurement results are shown in Table 2. Table 2

[0048] Note: * indicates P<0.05 compared with Example 1 group, # indicates P<0.05 compared with Example 2 group.

[0049] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. An absorbable synthetic spider silk suture, characterized in that, The raw material components include the following parts by weight: 10-15 parts of polymer material, 80-180 parts of solvent, 0.05-0.15 parts of type I collagen, 8-12 parts of acetic acid solution, and 0.05-0.25 parts of antibacterial agent.

2. The absorbable artificial spider silk suture according to claim 1, characterized in that, The polymeric material is a mixture of poly-L-lactic acid and polyglycolic acid-trimethylene carbonate copolymer in a mass ratio of 1:1; the molecular weight of the poly-L-lactic acid is 200,000-400,000 Da, and the molecular weight of the polyglycolic acid-trimethylene carbonate copolymer is 100,000-200,000 Da.

3. The absorbable artificial spider silk suture according to claim 1, characterized in that, The solvent is dichloromethane and / or N,N-dimethylformamide.

4. The absorbable artificial spider silk suture according to claim 1, characterized in that, The molecular weight of the type I collagen is 200,000-400,000 Da.

5. The absorbable artificial spider silk suture according to claim 1, characterized in that, The antibacterial agent is a mixed antibacterial agent consisting of histamine 5 and human α-defensin 5 mixed in a mass ratio of 1:

1.

6. The absorbable artificial spider silk suture according to claim 1, characterized in that, The antibacterial agent is a mixed antibacterial agent consisting of proanthocyanidins and tannic acid in a mass ratio of 3:

1.

7. The method for preparing the absorbable artificial spider silk suture according to claim 1, characterized in that, The mass concentration of the acetic acid solution is 2-4%.

8. The method for preparing the absorbable artificial spider silk suture according to claim 1, characterized in that, Follow these steps: (1) Dissolve 10-15g of polymer material in 100mL of solvent, stir magnetically for 3-5h, add 0.05-0.25g of antibacterial agent, stir and mix evenly to obtain core spinning solution; (2) Dissolve 0.05-0.15g of type I collagen in 8-12mL of 2-4% acetic acid solution, and shear and stir for 4-8h to obtain collagen gel; (3) Take 50 mL of the collagen gel prepared in step (2) and mix it with 100 mL of the core spinning solution prepared in step (1). Let it stand until the solution separates into layers again. Then, remove the lower layer of viscous solution to obtain the middle layer spinning solution. (4) Use two 5 ml syringes to draw 0.5 ml of core spinning solution and 0.5 ml of intermediate spinning solution; connect the core spinning solution syringe to the center of the coaxial spinning needle, and connect the intermediate spinning solution syringe to the outer channel. Set the advance speed to 0.2-0.4 mm / min; adjust the speed of the high-speed receiving roller to 2000-4000 rpm and the distance between the spinning needle and the needle to 10-20 cm. Set the voltage to -1+18 kV. After adjusting the parameters, start spinning to obtain a whole fiber film and remove it. (5) Cut the whole fiber film into 2-6 strips. Cut each fiber strip at a 45° angle on both sides to form an eccentric triangle. Continue to overlap the fiber strips at half a length interval and align the cuts. Splice the fibers continuously by twisting them in a Z-shaped twisting direction, with a twist of 0.4-0.6 turns / cm and a pre-stretch force of 20-40g, and fix them overnight. (6) After the fiber bundle is completely dry, immerse the fiber bundle in collagen gel for 2-4 hours, take it out and freeze dry to obtain absorbable artificial spider silk suture.

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