Degradable ureteral stent and its manufacturing method

Abstract

The present invention provides a degradable ureteral stent and a manufacturing method thereof, the degradable ureteral stent is a hollow tubular structure (1), has a fixing structure (2) at both ends or one end to prevent slipping, and has several outlet side holes (3) penetrating the tubular wall, and the material used is a composite material formed by at least glycolide-ε-caprolactone copolymer, ethylene oxide polymer, and medical contrast agent. The weight percentage content of glycolide in the glycolide-ε-caprolactone copolymer is 51%-58%, so that the copolymer has suitable mechanical strength and flexibility, and gradually becomes softer with the longer decomposition time. At the same time, by adding a certain percentage of ethylene oxide polymer, its tensile modulus is lower after decomposition, and it becomes more flexible and smooth, so that the decomposition fragments are less likely to clog and are easily discharged outside the body, which is more suitable for the manufacture of degradable ureteral.

Description

[Technical field]

[0001] The present invention is in the field of biomedical materials and medical devices, and more particularly relates to a degradable ureteral stent and a method for making the same. [Background technology]

[0002] Ureteral stents have been widely used in urological surgery, and are used in the treatment of upper urinary tract surgery, lithotripsy using a lithotripsy device, dilation of ureteral stricture, etc. They can be embedded in the ureter to allow urination and play an important role in preventing ureteral stricture.

[0003] The ureteral stents used in conventional clinical practice are all non-degradable and made of flexible polyurethane elastomer or silicone rubber materials. The polyurethane stent tube is hard and easy to place, while the silicone rubber stent tube is soft and has a slightly inferior placement performance. These two types of non-degradable ureteral stents do not change their hardness after insertion, and after the discharge function is completed, they need to be pulled out through an invasive operation, i.e., a cystoscope, which causes pain to the patient and may cause complications such as infection. Therefore, the research and development of degradable ureteral stents has important clinical value.

[0004] Depending on the requirements of clinical cases, the duration of discharge by ureteral stents varies. Short-term temporary urination is generally about 1-2 weeks for mild ureteral damage, simple stones, preoperative stents, etc. Normal temporary urination is 3-6 weeks, so different degradable materials need to be used. The basic requirement common to stents is that they have the mechanical properties of elastic materials and their broken fragments can be completely discharged from the body as soon as possible, otherwise the risk of a series of complications will increase.

[0005] Foreign literature (Lumiaho, J, J. Endourol. 1999, 13, 107-112; Laaksovirta, S Laurila M. et al. J urol, 167:1527, 2002) has reported the use of degradable polylactic acid (PLLA) or lactide / glycolide copolymer (PLGA) as raw materials to manufacture ureteral stents. However, PLLA and PLGA materials are plastics, which are less flexible and the decomposition fragments are hard, and are highly likely to penetrate and clog the renal pelvis, causing various complications.

[0006] Patent Documents 1 and 2 disclose a degradable ureteral stent, which relates to a glycolide-ε-caprolactone copolymer material, which has the mechanical properties of an elastic material within a certain range of composition ratio. However, such a copolymer formed from a soft segment monomer (ε-caprolactone) and a hard segment monomer (glycolide) tends to degrade in water and become harder. This is because the hard segment structure, such as the glycolide segment, in the material tends to crystallize during the decomposition process, which makes it easy for it to become clogged and retained in sites such as the renal pelvis.

[0007] As described above, the materials available in the prior art do not meet the requirements of having mechanical properties similar to those of silicone rubber and polyurethane elastic materials, and furthermore, not allowing degraded fragments to get stuck or remain in locations such as the renal pelvis. This remains an important point that limits the development of research in this field, and is also the main reason why degradable ureteral stents are not yet commercially available. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] CN1672739A [Patent Document 2] CN112516390A Summary of the Invention

[0009] In view of the above-mentioned shortcomings in the prior art, the present invention provides a degradable ureteral stent, which has the mechanical strength of an elastic material, has a high initial hardness (or modulus), is easy to deploy, and gradually softens as it is degraded in urine, making it easy to be expelled from the body.

[0010] The technical solutions of the present invention are as follows: A degradable ureteral stent is manufactured using a composite material, the composite material including at least a glycolide-ε-caprolactone copolymer, an ethylene oxide polymer, and barium sulfate as a medical contrast agent, the composite material being formed by mixing them, the relative contents of which are: 1) The weight percent content of glycolide-ε-caprolactone copolymer is 47% to 80%; 2) The weight percent content of ethylene oxide polymer is 2% to 8%; 3) The weight percent content of barium sulfate is 18% to 45%; The weight percent content of glycolide in the glycolide-ε-caprolactone copolymer is 51% to 58%, and the weight percent content of ε-caprolactone is 42% to 49%.

[0011] The ureteral stent of the present invention achieves the above objectives by utilizing a degradable composite material formed by blending glycolide-ε-caprolactone copolymer, ethylene oxide polymer, and barium sulfate.

[0012] From the results of the present invention and related research, it can be seen that if the stent tube is hard, the decomposition fragments are easily stuck at the renal pelvis, so the flexibility of the base material is an important influencing factor. Common degradable elastic materials such as glycolide-ε-caprolactone copolymer, L-lactide / ε-caprolactone copolymer, etc. often become harder and harder during the decomposition process, and it is difficult for the decomposition fragments or fragments to pass through the ureteral stenosis site. However, from the research of the present invention, it has been found that within the appropriate ratio range of the comonomer and using an appropriate polymerization process, the glycolide-ε-caprolactone copolymer can be decomposed in water or urine and gradually softened, which is a suitable elastic material with good mechanical strength and flexibility, and the appropriate ratio range of the comonomer is 51%-58% by weight of glycolide. When the weight percentage content of glycolide is more than 58%, the copolymer has a significant tendency to crystallize and becomes hard during the decomposition process, and when the weight percentage content of glycolide is lower than 51%, the mechanical properties of the copolymer are too low and too soft.

[0013] The present invention further discovered that by adding a certain content of ethylene oxide polymer, such as polyethylene glycol or polyoxyethylene, to the above-mentioned glycolide-ε-caprolactone copolymer material, the composite material can be gradually made softer during the process of decomposition, with a smoother surface, easier to disintegrate and crush, which is favorable for the discharge of broken fragments of the tubular stent.

[0014] The barium sulfate used in the degradable ureteral stent of the present invention is a commonly used medical contrast medium, has good compatibility with the above-mentioned materials, and has a certain reinforcing effect.

[0015] In the degradable ureteral stent of the present invention, the glycolide-ε-caprolactone copolymer has an intrinsic viscosity of 1.30 to 3.00 dl / g measured in hexafluoroisopropanol at a concentration of 0.1 g / dl at 25±1° C., and the higher the viscosity, the longer the decomposition maintenance time, so that the expulsion time of the stent tube can be adjusted by adjusting the intrinsic viscosity.

[0016] In the degradable ureteral stent of the present invention, the ethylene oxide polymer is polyethylene glycol, polyethylene glycol monomethyl ether, polyethylene glycol dimethyl ether, or polyoxyethylene.

[0017] Preferably, the weight ratio of the ethylene oxide polymer in the composite material is 2% to 8%, and the higher the content of the ethylene oxide polymer, the softer the composite material becomes and the faster it decomposes.

[0018] In the degradable ureteral stent of the present invention, the molecular weight of the polyethylene glycol, polyethylene glycol monomethyl ether, polyethylene glycol dimethyl ether, and polyoxyethylene is 1,000 Da to 1,000,000 Da.

[0019] Preferably, in the degradable ureteral stent of the present invention, the molecular weight of the ethylene oxide polymer, polyethylene glycol, polyethylene glycol monomethyl ether, or polyethylene glycol dimethyl ether, is 5,000 Da to 40,000 Da.

[0020] Preferably, in the degradable ureteral stent of the present invention, the ethylene oxide polymer is polyoxyethylene and has a molecular weight of 50,000 Da to 400,000 Da. In the degradable ureteral stent of the present invention, barium sulfate can be replaced with other medical contrast agents, including bismuth subcarbonate, metallic contrast agents, and the contrast agents used may be more than one type.

[0021] In the degradable ureteral stent of the present invention, the glycolide-ε-caprolactone copolymer can be produced by the following method.

[0022] Under nitrogen protection, stannous octanoate, ε-caprolactone, and glycolide are added in this order in a mass ratio of 0.005% to 0.1% to a reactor equipped with a stirrer, and while stirring, the temperature of the reaction system is raised from room temperature to 165°C to 200°C within 30 minutes, maintained for 18 to 30 hours, and further maintained under vacuum for 1 to 4 hours. The copolymer in the reactor is transferred and crushed, and then placed in a vacuum oven at 50°C to 110°C and vacuum dried for 8 to 24 hours.

[0023] The degradable ureteral stent of the present invention has a hollow tubular structure (1) having a fixing structure (2) at both ends or one end to prevent slippage, the fixing structure preferably having a circular tubular coil shape and having several discharge side holes (3) that further penetrate the tubular wall, and the tubular diameter is 1.0 to 4.0 mm.

[0024] The degradable ureteral stent of the present invention is produced by a melt extrusion method, the specific method being as follows.

[0025] A certain amount of glycolide-ε-caprolactone copolymer, ethylene oxide polymer, and medical contrast agent are uniformly mixed, and then extruded at 120°C to 160°C using an extruder to obtain a degradable elastic tubular material. The degradable elastic tubular material is then shaped into a curved tube at 50°C to 80°C to form a fixed structure having a coil at one or both ends, and then perforated to obtain the degradable ureteral stent.

[0026] The initial modulus of the degradable ureteral stent of the present invention at 100% deformation is 2 MPa to 10 MPa, and the modulus at 100% deformation after degradation is equal to or less than the initial value. The initial Shore hardness A of the material used is 70 to 95, and the Shore hardness A after degradation is equal to or less than the initial value.

[0027] In the degradable ureteral stent of the present invention, various additives, including but not limited to plasticizers, lubricants, pigments, antioxidants, hydrolysis inhibitors, melt thickeners, chain extenders, reinforcing agents, and polymer modifiers, may be added in a conventional manner to achieve different purposes during melt extrusion of the tube, which additives help improve the processability, degradability, interface properties, and mechanical properties of the stent.

[0028] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0029] The present invention controls the content of glycolide monomer in the glycolide-ε-caprolactone copolymer to ensure that the copolymer has suitable mechanical strength and flexibility, and gradually becomes softer with the increase in degradation time. At the same time, by adding a certain proportion of ethylene oxide polymer, the copolymer has a lower tensile modulus after degradation, and is more flexible and smooth, which is more suitable for manufacturing degradable ureters. [Brief description of the drawings]

[0030] [Figure 1] FIG. 1 shows medical images of the degradable ureteral stent of the present invention expelled from the animal body. In FIG. 1, (A) is the X-ray film at the time of insertion, (B) is the X-ray film at the time of rupture, (C) is the X-ray film after expulsion into the bladder, and (D) is the expelled degraded fragments. [Diagram 2] FIG. 1 is a schematic diagram of a degradable ureteral stent of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0031] Example 1 Preparation of Glycolide-ε-caprolactone Copolymer 1 0.04% stannous octanoate catalyst, 570 grams of ε-caprolactone monomer (CL) and 580 grams of glycolide monomer (GA) are sequentially placed in a 3L reactor, and under nitrogen protection, the reaction system temperature is raised to 180°C in 25 minutes, and the reaction is carried out for 25 hours at a stirring speed of 10-20 revolutions per minute, and the mixture is kept under vacuum for 2 hours. The copolymer in the reactor is transferred and crushed, and then placed in a vacuum oven at 90°C and vacuum dried for 24 hours to obtain glycolide-ε-caprolactone copolymer 1 (PGC1).

[0032] 1The weight percentage content of glycolide and ε-caprolactone in the copolymer is determined by H nuclear magnetic resonance spectroscopy, with hexafluoroisopropanol as the solvent.

[0033] The copolymer is prepared in a hexafluoroisopropanol solution having a concentration of 0.1 g / dl, and its intrinsic viscosity is measured at 25° C. using an Ubbelohde viscometer.

[0034] The copolymer is prepared into a sheet having a thickness of 2 mm at 140° C. by using a method of thermoforming in a vulcanizing press, and the Shore hardness A of the material is measured by a Shore hardness tester.

[0035] The copolymer is prepared into a dumbbell-shaped piece with a thickness of 2 mm in the same manner as above, and the breaking tensile strength and breaking elongation of the material are tested in a universal testing machine at a speed of 200 mm / min.

[0036] In vitro degradation studies of the materials are carried out in simulated urine at 37° C. and the Shore A hardness of the materials is measured periodically.

[0037] Example 2 Preparation of glycolide-ε-caprolactone copolymer 2 0.02% stannous octanoate catalyst, 540 grams of ε-caprolactone monomer (CL) and 590 grams of glycolide monomer (GA) are sequentially placed in a 3L reactor, and under nitrogen protection, the reaction system temperature is raised to 170°C in 20 minutes, and the reaction is carried out for 28 hours at a stirring speed of 10-20 revolutions per minute, and the mixture is kept under vacuum for 1 hour. The copolymer in the reactor is transferred and crushed, and then placed in a vacuum oven at 90°C and vacuum dried for 24 hours to obtain glycolide-ε-caprolactone copolymer 2 (PGC2).

[0038] The performance test of the above copolymer was carried out by the method described in Example 1, and the test results are shown in Table 1.

[0039] Example 3 Preparation of glycolide-ε-caprolactone copolymer 3 0.03% stannous octanoate catalyst, 530 grams of ε-caprolactone monomer (CL) and 600 grams of glycolide monomer (GA) are sequentially placed in a 3L reactor, and under nitrogen protection, the reaction system temperature is raised to 190°C in 30 minutes, and the reaction is carried out for 22 hours at a stirring speed of 10-20 revolutions per minute, and the mixture is kept under vacuum for 4 hours. The copolymer in the reactor is transferred and crushed, and then placed in a vacuum oven at 90°C and vacuum dried for 24 hours to obtain glycolide-ε-caprolactone copolymer 3 (PGC3).

[0040] The performance test of the above copolymer was carried out by the method described in Example 1, and the test results are shown in Table 1. Example 4 Preparation of glycolide-ε-caprolactone copolymer 4 0.05% stannous octanoate catalyst, 480 grams of ε-caprolactone monomer (CL) and 600 grams of glycolide monomer (GA) are sequentially placed in a 3L reactor, and under nitrogen protection, the reaction system temperature is raised to 195°C in 30 minutes, and the reaction is carried out for 18 hours at a stirring speed of 10-20 revolutions per minute, and the mixture is kept under vacuum for 4 hours. The copolymer in the reactor is transferred and crushed, and then placed in a vacuum oven at 90°C and vacuum dried for 24 hours to obtain glycolide-ε-caprolactone copolymer 4 (PGC4).

[0041] The performance test of the above copolymer was carried out by the method described in Example 1, and the test results are shown in Table 1.

[0042] Example 5 Preparation of Glycolide-ε-caprolactone Copolymer 5 0.01% stannous octanoate catalyst, 470 grams of ε-caprolactone monomer (CL) and 630 grams of glycolide monomer (GA) are sequentially placed in a 3L reactor, and under nitrogen protection, the reaction system temperature is raised to 190°C in 30 minutes, and the reaction is carried out for 20 hours at a stirring speed of 10-20 revolutions per minute, and the mixture is kept under vacuum for 2 hours. The copolymer in the reactor is transferred and crushed, and then placed in a vacuum oven at 90°C and vacuum dried for 24 hours to obtain glycolide-ε-caprolactone copolymer 5 (PGC5).

[0043] The performance test of the above copolymer was carried out by the method described in Example 1, and the test results are shown in Table 1. Example 6 Preparation of Glycolide-ε-caprolactone Copolymer 6 0.01% stannous octanoate catalyst, 470 grams of ε-caprolactone monomer (CL) and 660 grams of glycolide monomer (GA) are sequentially placed in a 3L reactor, and under nitrogen protection, the reaction system temperature is raised to 184°C in 26 minutes, and the reaction is carried out for 23 hours at a stirring speed of 10-20 revolutions per minute, and the mixture is kept under vacuum for 3 hours. The copolymer in the reactor is transferred and crushed, and then placed in a vacuum oven at 90°C and vacuum dried for 24 hours to obtain glycolide-ε-caprolactone copolymer 6 (PGC6).

[0044] The performance test of the above copolymer was carried out by the method described in Example 1, and the test results are shown in Table 1.

[0045] Table 1 JPEG2025515950000002.jpg63148

[0046] As can be seen from the above results, the glycolide-ε-caprolactone copolymer described in the present invention has a higher hardness as the glycolide content therein is higher. When the glycolide content therein is 51% to 58%, its Shore hardness A is equivalent to that of polyurethane (75 to 95) and silicone rubber (50 to 70), and it is suitable for use as a ureteral stent. As shown by the degradation results in simulated urine at 37°C, the hardness of PGC1 to PGC5 decreases during the degradation process. The glycolide content in PGC6 is more than 58%, and its hardness is high, and it becomes harder with the increase in degradation time. When the glycolide content is less than 51%, its tensile strength is low.

[0047] Example 7 Preparation of a composite material of glycolide-ε-caprolactone copolymer, polyethylene glycol, and barium sulfate 200 grams of the above-prepared glycolide-ε-caprolactone copolymer (PGC), a certain amount of polyethylene glycol 20000 (PEG2) or polyethylene glycol 5000 (PEG5), and medical barium sulfate (Ba) are mixed uniformly, and then further mixed and granulated by a twin-screw extruder, the temperature of the extruder is 120°C to 150°C, and the obtained composite pellets are further prepared into a composite sheet of the above three materials with a thickness of 2 mm at 140°C by a vulcanizing press, which is used for the tensile strength and hardness tests, and the dynamic friction coefficient of the composite material is tested according to the method specified in ASTM-D1894. The results are shown in Table 2.

[0048] Table 2 JPEG2025515950000003.jpg91162

[0049] As can be seen from the above results, the hardness change of the composite materials containing PEG during the decomposition process in the simulated urine obviously decreased with increasing decomposition time, and the higher the PEG content, the greater the decrease in hardness. Composite material 3 without PEG added showed a smaller decrease in hardness than the composite material with PEG added. Composite materials 7 and 8 used glycolide-ε-caprolactone copolymer had a glycolide content of more than 58% by weight, so their Shore hardness A increased or changed less with the extension of the decomposition time. The composite material with PEG added showed a smaller dynamic friction coefficient and a smoother surface.

[0050] Example 8 Preparation of a composite material of glycolide-ε-caprolactone copolymer, polyoxyethylene, and barium sulfate 200 grams of the above-prepared glycolide-ε-caprolactone copolymer (PGC), a certain amount of polyoxyethylene (PEO, molecular weight 200000 Da) and medical barium sulfate (Ba) are mixed uniformly, and then further mixed and granulated by a twin screw extruder, the temperature of the extruder is 120°C to 140°C, and the obtained composite pellets are further produced into a sheet with a thickness of 2 mm at 140°C by a vulcanizing press, which is used for the test of tensile strength and hardness, and the dynamic friction coefficient of the composite material is tested according to the method specified in ASTM-D1894. The results are shown in Table 3.

[0051] Table 3 JPEG2025515950000004.jpg57145

[0052] The above-mentioned composite materials of glycolide-ε-caprolactone copolymer, polyoxyethylene and medical barium sulfate have a similar pattern in the change of hardness during the decomposition process, and all of them obviously decrease with the increase of decomposition time. The higher the content of polyoxyethylene, the greater the decrease in hardness, but if the content of polyoxyethylene is too high, the strength will be further reduced, which is unfavorable for fixation. The composite material with added polyoxyethylene shows a smaller dynamic friction coefficient and a smoother surface.

[0053] Example 9 Preparation of a composite material of glycolide-ε-caprolactone copolymer, polyethylene glycol, and bismuth subcarbonate 200 grams of the above prepared glycolide-ε-caprolactone copolymer (PGC), a certain amount of polyethylene glycol 20000 (PEG2) or polyethylene glycol 5000 (PEG5), and medical bismuth subcarbonate (Bi) are mixed uniformly, and then further mixed and granulated by a twin screw extruder, the temperature of the extruder is 120℃-140℃, and the obtained composite pellets are further manufactured into a composite sheet of the above three materials with a thickness of 2mm at 140℃ by a vulcanizing press, which is used for the tensile strength and hardness test, and the dynamic friction coefficient of the composite material is tested according to the method specified in ASTM-D1894. The results are shown in Table 4.

[0054] Table 4 JPEG2025515950000005.jpg39125

[0055] The properties and change regularity of the above glycolide-ε-caprolactone copolymer, polyethylene glycol, bismuth subcarbonate composite materials are similar to those of the above composite materials, that is, the hardness changes of the composite materials during the decomposition process in the simulated urine all decrease obviously with the increase of decomposition time, and the kinetic friction coefficient of the composite material with the addition of PEG is smaller, and the above regularity is independent of the type of contrast agent used.

[0056] Example 10. Preparation of a degradable ureteral stent The composite material produced in the above examples was extruded at 120°C to 150°C in an extruder to obtain a degradable elastic tubular body 1, the outer diameter of which was 2 mm and the inner diameter of which was 1.1 mm. The tubular body was then shaped into a curved tube at 50°C to 80°C to form a fixed structure of a curled tubular coil 2 at one or both ends, and then holes were punched (vertical hole diameter 1.0 mm) at equal distances (hole pitch 50 mm) in the tubular body using a punching device, followed by forming discharge holes 3. The resulting degradable ureteral stent is as shown in Figure 2.

[0057] The materials were tested in a universal testing machine at a speed of 200 mm / min for their breaking tensile strength and tensile modulus (the tensile strength at 100% elongation, which characterizes the flexibility of the material in the same way as Shore hardness). The changes in the tensile modulus during the in vitro degradation process in simulated urine at 37°C were also measured. The results are shown in Table 5.

[0058] Example 11: Degradation experiment of degradable ureteral stent in animal body A miniature pig was selected, and after undergoing general anesthesia, a ureteral stent was implanted in the ureter on both the left and right sides of the miniature pig by ureteroscope, with the upper end of the tubular coil fixed in the renal pelvis and the lower end of the tubular coil fixed in the bladder. After the operation, X-ray was used to observe whether the ureteral stent had fallen off, broken or been discharged at different times. A universal testing machine was used to test the tensile modulus of the stent tube at different times to characterize the change in its flexibility, and the results are shown in Table 5.

[0059] Table 5 JPEG2025515950000006.jpg73146

[0060] As shown above, ureteral stents 1, 2, and 3 contain ethylene oxide polymers, while ureteral stents 4 and 5 do not. All degradable stents can be completely discharged from the urinary system of animals, and the rupture time depends on factors such as the molecular weight of the material, the ratio of comonomers, the amount of ethylene oxide polymer added, and the process conditions during processing. However, ureteral stents 1, 2, and 3 containing ethylene oxide polymers have lower tensile modulus, softer, and smoother surfaces after degradation, and the time to be completely discharged from the body is shorter than ureteral stents 4 and 5 without ethylene oxide polymers, so there is less possibility of incrustation in the body. Although there is a certain difference in the initial modulus of each ureteral stent group, the difference is not large, and all of them can be smoothly placed. The modulus of commercially available silicone rubber stent tubes and polyurethane stent tubes does not change with degradation time. The tensile strength and modulus of the degradable ureteral stents of the present invention are between those of silicone rubber stents and polyurethane stents, and are closer to those of polyurethane stents.

[0061] FIG. 1 shows a medical image of the degradable ureteral stent of the present invention being expelled from the animal body. After decomposition, the stent was smoothly expelled from the renal pelvis, ureter, and bladder, without leaving any residual debris.

Claims

1. 1. A degradable ureteral stent comprising: The present invention is produced using a composite material, which comprises at least a glycolide-ε-caprolactone copolymer, an ethylene oxide polymer, and barium sulfate as a medical contrast agent, and is formed by mixing them, and the relative contents thereof are: 1) the weight percent content of glycolide-ε-caprolactone copolymer is 47% to 80%; 2) the weight percent content of ethylene oxide polymer is between 2% and 8%; 3) the weight percent content of barium sulfate is between 18% and 45%; A degradable ureteral stent, wherein the weight percent content of glycolide in the glycolide-ε-caprolactone copolymer is 51%-58%, and the weight percent content of ε-caprolactone is 42%-49%.

2. 2. The degradable ureteral stent according to claim 1, wherein the glycolide-ε-caprolactone copolymer has an intrinsic viscosity of 1.30 to 3.00 dl / g measured at 25±1° C. in hexafluoroisopropanol having a concentration of 0.1 g / dl.

3. the ethylene oxide polymer is polyethylene glycol, polyethylene glycol monomethyl ether, polyethylene glycol dimethyl ether, polyoxyethylene and ethylene oxide copolymer; 2. The degradable ureteral stent according to claim 1, wherein the molecular weight of the polyethylene glycol, polyethylene glycol monomethyl ether, polyethylene glycol dimethyl ether, or polyoxyethylene is 1,000 Da to 1,000,000 Da.

4. the ethylene oxide polymer is polyethylene glycol or polyethylene glycol monomethyl ether and has a molecular weight of 5,000 Da to 40,000 Da; or 4. The degradable ureteral stent according to claim 3, wherein the ethylene oxide polymer is polyoxyethylene and has a molecular weight of 50,000 Da to 400,000 Da.

5. 2. The degradable ureteral stent of claim 1, wherein barium sulfate is replaced with other medical contrast agents including one or more of bismuth subcarbonate, metallic contrast agents.

6. The degradable ureteral stent according to claim 1, characterized in that the degradable ureteral stent is a hollow circular tubular structure (1), has a fixing structure (2) at both ends or one end to prevent slipping, has several outlet side holes (3) that further penetrate the tubular wall, and has an outer diameter of 1.0 to 4.0 mm.

7. The degradable ureteral stent according to claim 1, characterized in that the modulus of the degradable ureteral stent at initial 100% deformation is 2 MPa to 10 MPa, the modulus at 100% deformation after degradation is equal to or less than the initial value, the initial Shore hardness A of the material used is 70 to 95, and the Shore hardness A after degradation is equal to or less than the initial value.

8. The degradable ureteral stent according to claim 1 or 6, further comprising an auxiliary agent added thereto, the auxiliary agent including a plasticizer, a lubricant, a pigment, an antioxidant, a hydrolysis inhibitor, a melt thickener, a chain extender, a reinforcing agent, and a polymer modifier.

9. A method for producing the degradable ureteral stent according to any one of claims 1 to 8, comprising the steps of: A method for producing a degradable ureteral stent, comprising: homogeneously mixing a glycolide-ε-caprolactone copolymer, an ethylene oxide polymer, and a medical contrast agent, followed by extrusion molding at 120°C to 160°C using an extruder to obtain a degradable elastic tubular material; shaping the degradable elastic tubular material into a curved tube at 50°C to 80°C to form a fixed structure having a tubular coil at one or both ends; and then perforating the tube to obtain the degradable ureteral stent.

10. moreover, The method for producing a degradable ureteral stent according to claim 9, further comprising the steps of: adding stannous octanoate, ε-caprolactone and glycolide in a mass ratio of 0.005% to 0.1% in a reactor equipped with a stirrer under nitrogen protection, raising the temperature of the reaction system from room temperature to 165°C to 200°C within 30 minutes while stirring, maintaining the temperature for 18 to 30 hours, maintaining the temperature under vacuum for 1 to 4 hours, transferring the copolymer in the reactor, crushing the copolymer, and then placing the copolymer in a vacuum oven at 50°C to 110°C for vacuum drying for 8 to 24 hours.

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