Ureteral stent tube and preparation method thereof

Abstract

The present application relates to the field of medical devices and discloses a ureteral stent and a preparation method thereof. The ureteral stent comprises a stent body and a nanofiber membrane. The stent body is woven into a 90-140ppi tube by spinning component A and component B in a mass ratio of 4:(1-2). The spun yarn obtained by component B is melted by heating and then combined with the spun yarn obtained by component A. The stent body is obtained after cooling. The nanofiber membrane components include polyethylene glycol and polyglycolide, as well as fucoidan-modified chitosan. A lubricant is sprayed on one side of the nanofiber membrane away from the stent body, and the membrane is wound around the outer surface of the stent body by electrostatic adsorption. The ureteral stent increases the stability and stiffness of the tube wall, improves the mechanical strength and durability, and the material is biocompatible and biodegradable, and can reduce irritation and damage to the urothelium, and prevent urothelial tissue ingrowth and adhesion.

Description

Technical Field

[0001] The present application relates to the field of medical devices, and more specifically, to a ureteral stent and a preparation method thereof. Background Art

[0002] Ureteral stents are medical devices used to treat diseases and problems related to the urinary tract and are widely used in urological surgeries. Ureteral stents may have been used as an auxiliary tool in some open surgeries in the 19th century, primarily to drain urine and maintain ureteral continuity.

[0003] With the continuous advancement of medical technology, ureteral stents have undergone significant improvements in design and materials. In particular, in the 20th century, with the continuous development of plastic manufacturing processes, polyethylene and polyvinyl alcohol began to be used in ureteral stent research. These stents are relatively rigid and easy to place. Ureteral stent designs have also undergone continuous improvement and innovation. From the original straight tube stent to stents with distal bulbs, and then to single-J and double-J stent designs, each is designed to better adapt to the patient's anatomy and reduce the incidence of stent migration and irritation.

[0004] Currently, stent placement in the ureter is performed through an invasive procedure. Since the stent is often made of a hydrophobic polymer, it can easily damage the urothelium during implantation and often requires surgical removal, causing secondary damage. Degradable ureteral stents offer a solution to this secondary injury. However, during degradation within the patient's urethra, if the degradable material adheres to the upper urethral tissue, it can make it difficult to remove the degraded fragments in a timely manner, increasing the risk of urethral obstruction. Summary of the Invention

[0005] In order to solve the above problems, the present application provides a ureteral stent tube and a preparation method thereof.

[0006] The present application provides a ureteral stent tube adopting the following technical solution:

[0007] A ureteral stent comprises a stent body and a nanofiber membrane. The nanofiber membrane is wound on the outer surface of the stent body by electrostatic adsorption. The nanofiber membrane components include polyethylene glycol and polyglycolide. The components of the stent body include component A and component B. Component A includes one or more of polyglycolide, polyglycolide, and polylactide. Component B includes one or more of polycaprolactone and polydioxanone.

[0008] By adopting the above technical solution, polyethylene glycol and polyglycolide are selected as the materials of the nanofiber membrane, which are both degradable materials with good biocompatibility. In addition, the nanometer-scale monofilament diameter allows the nanofiber membrane to enter the urethra tube relatively smoothly, which can further reduce the stimulation and damage to the urothelial tissue. And because of the dense barrier effect played by the nanofiber membrane, it can prevent the urothelial tissue from growing in and adhering to the urothelial tissue. Component A and component B of the stent tube body are selected from materials with good biodegradability. These materials can gradually degrade in the body to form smaller molecular fragments, and the degradation rates of the materials used in component A and component B and the nanofiber membrane are different. This makes the degradation time of the urethral tube stent relatively dispersed during use, and does not produce degradation products in a concentrated manner. It is easier to be metabolized and excreted by the body, reducing the risk of urethral blockage.

[0009] Optionally, the nanofiber membrane component further includes fucoidan-modified chitosan.

[0010] Optionally, the preparation method of the fucoidan-modified chitosan is:

[0011] Mix fucoidan powder with deionized water in a mass ratio of 1:(6-8), heat to 50-70°C and stir for 30-50 minutes, filter the fucoidan solution through a 0.4-0.5 μm filter membrane to remove insoluble matter;

[0012] Mix chitosan powder with a 1-3% dilute hydrochloric acid solution in a mass ratio of 1:(15-20), heat to 45-55°C and stir for 50-60 minutes, and filter the chitosan solution through a 0.4-0.5 μm filter membrane to remove insoluble matter;

[0013] The pretreated fucoidan solution and chitosan solution were mixed in a mass ratio of 1:(1-3) and stirred at 50-60°C for 2-3h. During the reaction, the pH value of the solution was adjusted to about 4-6.

[0014] After the reaction is completed, 1-2 times the mass of ethanol is added to the solution, and the solution is centrifuged at a speed of 4000-5000 rpm for 5-15 minutes. The precipitate is collected and washed with deionized water for 2-4 times. The washed precipitate is vacuum-dried at 40-50° C. for 18-24 hours to obtain fucoidan-modified chitosan.

[0015] By adopting the above technical solution, the hydrophilicity of fucoidan-modified chitosan is improved. After fucoidan-modified chitosan is added to the nanofiber membrane and comes into contact with water molecules, it can play a certain lubricating role, thereby reducing friction with the urothelial tissue and reducing physical damage to the urothelial tissue during implantation. In addition, as the stent tube degrades, the nanofiber membrane will also gradually degrade, but its lubricating properties can still be maintained during the degradation process, thereby continuously reducing friction in the urethra and reducing damage and discomfort. Both fucoidan and chitosan have antibacterial properties. When fucoidan is combined with chitosan, the modified material formed further enhances the antibacterial effect. The introduction of antibacterial materials can significantly reduce the risk of complications caused by urinary bacterial infections.

[0016] Optionally, a lubricant is sprayed on the side of the nanofiber membrane facing away from the stent tube body. The lubricant comprises 40-60 parts of acetylated hyaluronic acid, 30-40 parts of deionized water, 5-10 parts of phospholipids and 5-15 parts of gum arabic in parts by weight.

[0017] By adopting the above technical solution, acetylated hyaluronic acid has good stability and lubricating properties. It can form a smooth protective layer on the surface of the nanofiber membrane, significantly reducing the friction between the stent tube and the urothelium, thereby reducing physical damage to the urothelium. Phospholipid molecules can form a stable double-layer membrane structure in an aqueous solution. This structure has excellent lubrication and friction reduction effects, which can further reduce the resistance during stent implantation. The addition of gum arabic can not only improve the adhesion of the lubricant to the surface of the nanofiber membrane, but also has antibacterial properties. The various components in the lubricant have good biocompatibility and can reduce the stimulation of the stent tube on urothelial cells.

[0018] In a second aspect, the present application provides a method for preparing a ureteral stent tube, which adopts the following technical solution:

[0019] A method for preparing a ureteral stent comprises the following steps:

[0020] 30-50 parts of polyethylene glycol and 20-30 parts of polyglycolide are mixed by weight and then electrospun to obtain a nanofiber membrane; component A and component B are extruded and spun separately, with a spinning diameter of 0.2-0.02 mm, and the spun yarns obtained by component A and component B are blended and woven into a 90-140 ppi tube at a mass ratio of 4:(1-2), and then heated to 110-120° C., the spun yarns obtained by component B are melted and combined with the spun yarns obtained by component A, and then cooled to obtain a stent tube body;

[0021] The surface of the stent tube body is cleaned and polished, and the nanofiber membrane is wound around the outside of the stent tube body by electrostatic adsorption to obtain a ureteral stent tube. The prepared ureteral stent tube is cleaned and disinfected.

[0022] By adopting the above technical solution, a dense nanofiber membrane is obtained by electrospinning, which ensures the structural stability of the membrane and the softness of the fiber membrane, which is beneficial to reducing the foreign body sensation and preventing the ingrown epithelial tissue. Component A and component B are extruded and spun separately, and then woven into a tubular structure of 90-140ppi through blending. Subsequently, under the condition of heating to 110-120°C, the spinning of component B melts and combines with the spinning of component A, achieving a close combination of the two materials, giving the stent tube good toughness and structural strength, and preventing the urethral stent from deformation and damage during use. The nanofiber membrane is wound around the outside of the stent tube body by electrostatic adsorption, achieving a close combination of the nanofiber membrane and the stent tube body. The prepared ureteral stent is cleaned and disinfected to ensure the cleanliness and sterility of the stent tube and reduce the risk of infection.

[0023] Optionally, after the ureteral stent is cleaned, a lubricant needs to be sprayed on the surface of the nanofiber membrane, and the spraying thickness is 0.1-0.3 mm.

[0024] By employing this technical solution, spraying a lubricant onto the nanofiber membrane significantly enhances the stent's lubrication. The addition of the lubricant forms a smooth, protective layer on the stent's surface, reducing friction with the urothelial tissue, alleviating discomfort during implantation, and minimizing the risk of damage to the urethral mucosa. Precisely controlling the coating thickness ensures lubrication while minimizing patient discomfort.

[0025] Optionally, the polyethylene glycol, polyglycolide and fucoidan-modified chitosan are mixed and then electrospinned to prepare the nanofiber membrane.

[0026] Optionally, the braiding angle when the spun blend obtained by weaving component A and component B is 45-60°.

[0027] By adopting the above technical solution, the braiding angle between 45-60° can make the stent tube body have better strength and elasticity, ensuring that the ureteral stent tube maintains sufficient strength and elasticity while withstanding urine flow and changes in the body environment, thereby extending its service life.

[0028] In summary, this application has the following beneficial effects:

[0029] 1. Since the present application uses polyethylene glycol and polyglycolide as the materials of the nanofiber membrane, not only the degradability and biocompatibility of the material are ensured, but also the nanoscale monofilament diameter enables the fiber membrane to smoothly enter the urethra tube, reducing the stimulation and damage to the urothelial tissue. At the same time, the dense barrier provided by the nanofiber membrane effectively prevents the growth and adhesion of epithelial tissue. Component A and component B of the stent tube body are also selected from materials with good biodegradability. These materials gradually degrade in the body, and the difference in degradation rate avoids the concentrated production of degradation products, which helps to reduce the risk of urethral obstruction and improves the safety and biocompatibility of the stent tube.

[0030] 2. In this application, fucoidan-modified chitosan is preferably added to the nanofiber membrane, which not only significantly improves its hydrophilicity and lubricity, but also effectively reduces friction with the urothelial tissue and reduces physical damage during implantation. At the same time, as the stent gradually degrades, the nanofiber membrane can also maintain its lubricating properties, continuously reducing friction in the urethra and alleviating patient discomfort. In addition, the antibacterial properties of fucoidan and chitosan themselves are further enhanced after modification, significantly reducing the risk of urinary tract bacterial infection and the complications caused by it, providing a safer and more effective solution for the clinical application of ureteral stents.

[0031] 3. The present invention's method, through the weaving of a high-density nanofiber membrane, ensures structural stability and flexibility, while also helping to reduce foreign body sensation and prevent epithelial tissue ingrowth. Components A and B are spun and blended into a 90-140 ppi tubular structure. Component B is then melted and combined with component A under heating conditions, imparting excellent toughness and structural strength to the stent tube, preventing deformation and damage during use. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is a flow chart of the method for preparing a ureteral stent tube of the present application;

[0033] Figure 2 is a cross-sectional view of the ureteral stent tube of the present application;

[0034] Figure 3 This is a schematic diagram of the appearance of the stent tube body of the ureteral stent tube of the present application;

[0035] Figure 4 This is a schematic diagram of the appearance of the nanofiber membrane of the ureteral stent tube of the present application. DETAILED DESCRIPTION

[0036] The present application is further described in detail below with reference to the examples. It is particularly noted that if no specific conditions are specified in the following examples, the reactions are carried out according to conventional conditions or the conditions recommended by the manufacturer. Unless otherwise specified, the raw materials used in the following examples can be obtained from common commercial sources.

[0037] Preparation example of fucoidan-modified chitosan

[0038] Preparation Example 1

[0039] Preparation method of fucoidan modified chitosan:

[0040] Add 1 kg of fucoidan powder and 7 kg of deionized water into a clean container and stir. Heat the container to 60°C and stir continuously for 40 minutes. After stirring, filter the fucoidan solution through a filter membrane with a pore size of 0.4-0.5 μm to remove insoluble matter.

[0041] 1 kg of chitosan powder was added to 18 kg of 2% dilute hydrochloric acid solution, heated to 50 ° C and stirred with a stirrer for 60 minutes. After stirring, the chitosan solution was filtered using a 0.4-0.5 μm filter membrane to remove insoluble matter.

[0042] Mix 5 kg of fucoidan solution with 5 kg of chitosan solution, heat to 55°C and keep warm, stir at 30 r / min for 2.5 h. During the reaction, check the pH value of the reaction solution and use sodium hydroxide or dilute hydrochloric acid to adjust the pH value of the solution to maintain at 5;

[0043] After the reaction is completed, 10 kg of ethanol is added to the reaction solution and stirred evenly. The solution is centrifuged at 4500 rpm for 10 minutes, the precipitate is collected, and the precipitate is washed three times with deionized water. The washed precipitate is transferred to a vacuum drying oven and vacuum dried at 40-50°C for 20 hours to obtain fucoidan-modified chitosan.

[0044] Preparation Example 2

[0045] Preparation method of fucoidan-modified chitosan: The difference from Preparation Example 1 is that 5 kg of fucoidan solution is mixed with 10 kg of chitosan solution.

[0046] Preparation Example 3

[0047] Preparation method of fucoidan-modified chitosan: The difference from Preparation Example 1 is that 5 kg of fucoidan solution is mixed with 15 kg of chitosan solution.

[0048] Preparation Example 4

[0049] Preparation method of fucoidan-modified chitosan: The difference from Preparation Example 2 is that during the reaction, the pH value of the reaction solution is detected and the pH value of the solution is adjusted to 7 using sodium hydroxide or dilute hydrochloric acid.

[0050] Preparation Example 5

[0051] Preparation method of fucoidan-modified chitosan: The difference from Preparation Example 2 is that during the reaction, the pH value of the reaction solution is detected and the pH value of the solution is adjusted to 3 using sodium hydroxide or dilute hydrochloric acid.

[0052] Example

[0053] Example 1

[0054] A method for preparing a ureteral stent:

[0055] Prepare 4 kg of polyethylene glycol and 2 kg of polyglycolide as raw materials for nanofiber membranes. Dissolve the polyethylene glycol solution in 6 kg of ethanol and dissolve the polyglycolide in 4 kg of hexafluoroisopropanol. The two solutions are divided into a conjugate nozzle and conjugate electrospinning is performed to obtain nanofiber membranes.

[0056] Prepare 4 kg of polylactide as component A and 1.5 kg of polycaprolactone as component B, and place component A and component B into spinning equipment respectively for extrusion spinning. The spinning diameter range is 0.1±0.05 mm, and the spun yarns obtained from component A and component B are blended and woven around the bracket tube mold. The braiding angle is 55°, and the yarns are woven into a tubular structure with an outer diameter of 1.2 mm and a density of 120 ppi. The woven tubular structure is placed in a vacuum heating furnace and the heating temperature is set to 120°C to melt the spun yarn of component B. In the molten state, the spun yarn of component B is combined with the spun yarn of component A. The combined tubular structure is taken out of the heating furnace and naturally cooled to room temperature. After cooling, the spun yarn of component B is solidified and firmly combined with the spun yarn of component A to form the bracket tube body.

[0057] The stent tube body is cleaned to remove any bumps and burrs, and polished with a polishing machine to a smooth surface. The nanofiber membrane surface is cleaned to ensure it is free of damage and impurities, and cut to the stent tube body dimensions. A high-voltage generator is activated to create an electrostatic field between the electrode wire and the stent tube body. Using electrostatic attraction and controlling the winder, the nanofiber membrane is bonded to the outside of the stent tube body. A pressure roller is used to press the nanofiber membrane to ensure a tight fit.

[0058] Place the ureteral stent wrapped with the nanofiber membrane in a cleaning tank, rinse it with purified water, and air dry it. Place the cleaned ureteral stent in an ultraviolet disinfection device for disinfection. After disinfection, remove the ureteral stent, package it, and store it.

[0059] Example 2

[0060] A method for preparing a ureteral stent: The method is different from Example 1 in that 4 kg of poly(lactide-glycolide) is prepared as component A.

[0061] Example 3

[0062] A method for preparing a ureteral stent: The method is different from Example 1 in that 4 kg of polyglycolide is prepared as component A.

[0063] Example 4

[0064] A method for preparing a ureteral stent: The method is different from Example 1 in that 2 kg of poly(lactide-glycolide) and 2 kg of poly(lactide) are prepared as component A.

[0065] Example 5

[0066] A method for preparing a ureteral stent: The method is different from Example 1 in that 2 kg of poly(lactide-glycolide) and 2 kg of poly(glycolide) are prepared as component A.

[0067] Example 6

[0068] A method for preparing a ureteral stent: The method is different from Example 1 in that 2 kg of polyglycolide and 2 kg of polylactide are prepared as component A.

[0069] Example 7

[0070] A method for preparing a ureteral stent: The method is different from Example 1 in that 1 kg of poly(lactide-glycolide), 1 kg of poly(glycolide) and 2 kg of poly(lactide) are prepared as component A.

[0071] Example 8

[0072] A method for preparing a ureteral stent: The method is different from Example 1 in that 1.5 kg of polydioxanone is prepared as component B.

[0073] Example 9

[0074] A method for preparing a ureteral stent: The method is different from Example 1 in that 0.7 kg of polydioxanone and 0.8 kg of polycaprolactone are prepared as component B.

[0075] Example 10

[0076] A method for preparing a ureteral stent: This method differs from Example 1 in that 4 kg of polyethylene glycol, 2 kg of polyglycolide, and 1 kg of fucoidan-modified chitosan are prepared as raw materials for the nanofiber membrane. The polyethylene glycol solution is dissolved in 6 kg of ethanol, the polyglycolide is dissolved in 4 kg of hexafluoroisopropanol, and the fucoidan-modified chitosan is dissolved in 1% dilute hydrochloric acid. The three solutions are then dispensed onto a conjugate nozzle and conjugate electrospinning is performed to produce the nanofiber membrane. The fucoidan-modified chitosan is prepared according to Preparation Example 1.

[0077] Example 11

[0078] A method for preparing a ureteral stent: The difference from Example 10 is that the fucoidan-modified chitosan is prepared by Preparation Example 2.

[0079] Example 13

[0080] A method for preparing a ureteral stent: The difference from Example 10 is that the fucoidan-modified chitosan is prepared by Preparation Example 3.

[0081] Example 14

[0082] A method for preparing a ureteral stent: The difference from Example 1 is that after the ureteral stent is cleaned, a lubricant needs to be sprayed on the surface of the nanofiber membrane. The spraying thickness is 0.2 mm, and the lubricant contains 50 g of acetylated hyaluronic acid, 35 g of deionized water, 8 g of phospholipids and 10 g of gum arabic.

[0083] Comparative Example

[0084] Comparative Example 1

[0085] A method for preparing a ureteral stent: The difference from Example 10 is that the fucoidan-modified chitosan is prepared by Preparation Example 4.

[0086] Comparative Example 2

[0087] A method for preparing a ureteral stent: The difference from Example 10 is that the fucoidan-modified chitosan is prepared by Preparation Example 5.

[0088] Comparative Example 3

[0089] A method for preparing a ureteral stent tube: The difference from Example 1 is that 5.5 kg of polylactide is prepared, the polylactide is placed in a spinning device for extrusion spinning, the spinning diameter range is 0.1±0.05 mm, and the spun yarn obtained from the polylactide is blended and woven around the stent tube mold with a braiding angle of 55°, woven into a tubular structure with a density of 120 ppi to form the stent tube body.

[0090] Comparative Example 4

[0091] A method for preparing a ureteral stent tube: The difference from Example 1 is that 5.5 kg of polycaprolactone is prepared, the polycaprolactone is placed in a spinning device for extrusion spinning, the spinning diameter range is 0.1±0.05 mm, and the spun yarn obtained from the polycaprolactone is blended and woven around the stent tube mold with a braiding angle of 55°, woven into a tubular structure with a density of 120 ppi to form the stent tube body.

[0092] Comparative Example 5

[0093] A method for preparing a ureteral stent tube: the difference from Example 1 is that the braiding angle is 40°.

[0094] Performance testing

[0095] Detection method

[0096] The ureteral stents obtained in Example 1, Example 10, Example 13 and Comparative Examples 1-2 were tested using a COF-P01 inclined plane friction coefficient tester to calculate the surface friction coefficient.

[0097] The ureteral stents obtained in Examples 1-14 and Comparative Examples 1-5 were placed in a container simulating a urethral tube environment with a pH value between 5 and 7.0. The container was filled with simulated urine components, including water, electrolytes (sodium, potassium, chloride, etc.), and organic matter (urea, creatinine, etc.). The temperature was maintained at 37°C, and the degradation time was recorded.

[0098] Table 1 Friction coefficient test

[0099] Friction coefficient Example 1 0.11 Example 10 0.06 Example 13 0.02 Comparative Example 1 0.08 Comparative Example 2 0.09

[0100] Table 2 Degradation time

[0101]

[0102]

[0103]

[0104] From Example 10 and Comparative Examples 1-2 and Table 1, it can be seen that the product obtained by the preparation method of fucoidan-modified chitosan in the present application scheme is more effective when applied to nanofiber membranes, can achieve lower friction, and reduce the patient's discomfort.

[0105] Combining Example 1 and Comparative Examples 3-4 with Table 2, it can be seen that the blended weaving of the two components A and B in the present application solution can effectively achieve graded degradation of the stent tube, so that the degradation products will not be concentrated in the same time period to cause blockage and discomfort.

[0106] From Example 1 and Comparative Example 5 and Table 2, it can be seen that a braiding angle between 45° and 60° can provide the stent tube body with good strength and elasticity, ensuring that the ureteral stent tube maintains sufficient strength and elasticity while withstanding urine flow and changes in the body environment, thereby extending its service life.

[0107] Combining Examples 1, 10, and 13 with Table 1, it can be seen that fucoidan-modified chitosan increases hydrophilicity. Adding fucoidan-modified chitosan to the nanofiber membrane, upon contact with water molecules, provides a lubricating effect, thereby reducing friction with the urothelial tissue and minimizing physical damage to the urothelium during implantation. The addition of the lubricant forms a smooth protective layer on the stent surface, reducing friction with the urothelial tissue, alleviating discomfort during implantation, and minimizing the risk of damage to the urethral mucosa.

[0108] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make non-creative modifications to the present embodiment as needed, but as long as they are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. A ureteral stent, characterized in that: The invention comprises a stent tube body and a nanofiber membrane, wherein the nanofiber membrane is wound on the outer surface of the stent tube body by electrostatic adsorption, wherein the nanofiber membrane components include polyethylene glycol and polyglycolide, and the components of the stent tube body include component A and component B, wherein component A includes one or more of polyglycolide, poly(lactide-glycolide), and polylactide, and component B includes one or more of polycaprolactone and polydioxanone; the nanofiber membrane components also include fucoidan-modified chitosan; and the preparation method of the ureteral stent comprises the following steps: 30-50 parts of polyethylene glycol and 20-30 parts of polyglycolide are mixed by weight and then electrospun to obtain a nanofiber membrane; component A and component B are extruded and spun separately, with a spinning diameter of 0.2-0.02 mm, and the spun yarns obtained by component A and component B are blended and woven into a 90-140 ppi tube at a mass ratio of 4:(1-2), and then heated to 110-120° C., the spun yarns obtained by component B are melted and combined with the spun yarns obtained by component A, and then cooled to obtain a stent tube body; The surface of the stent tube body is cleaned and polished, and the nanofiber membrane is wound on the outside of the stent tube body by electrostatic adsorption to obtain a ureteral stent tube, and the prepared ureteral stent tube is cleaned and disinfected; 30-50 parts of polyethylene glycol, 20-30 parts of polyglycolide and 5-15 parts of fucoidan-modified chitosan are mixed and then electrospun to prepare the nanofiber membrane.

2. The ureteral stent according to claim 1, characterized in that: Preparation method of the fucoidan-modified chitosan: Mix fucoidan powder with deionized water in a mass ratio of 1:(6-8), heat to 50-70°C and stir for 30-50 minutes, filter the fucoidan solution through a 0.4-0.5 μm filter membrane to remove insoluble matter; Mix chitosan powder with a 1-3% dilute hydrochloric acid solution in a mass ratio of 1:(15-20), heat to 45-55°C and stir for 50-60 minutes, and filter the chitosan solution using a 0.4-0.5 μm filter membrane to remove insoluble matter. The pretreated fucoidan solution and chitosan solution were mixed in a mass ratio of 1:(1-3) and stirred at 50-60°C for 2-3h. During the reaction, the pH value of the solution was adjusted to 4-6; After the reaction is completed, 1-2 times the mass of ethanol is added to the solution, and the solution is centrifuged at a speed of 4000-5000 rpm for 5-15 minutes. The precipitate is collected and washed with deionized water for 2-4 times. The washed precipitate is vacuum-dried at 40-50° C. for 18-24 hours to obtain fucoidan-modified chitosan.

3. The ureteral stent according to claim 1, characterized in that: The side of the nanofiber membrane facing away from the stent tube body is also sprayed with a lubricant, which includes 40-60 parts of acetylated hyaluronic acid, 30-40 parts of deionized water, 5-10 parts of phospholipids and 5-15 parts of gum arabic in parts by weight. The spraying thickness is 0.1-0.3 mm.

4. The ureteral stent according to claim 1, characterized in that: The braiding angle when the spun blend obtained by the components A and B is braided is 45-60 degrees.

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