An observable core-shell structure surgical suture and its preparation method, occluder

Abstract

The application provides a visible core-shell structure surgical suture and a preparation method thereof and a plug, and belongs to the technical field of visible surgical suture manufacturing. The preparation method of the visible core-shell structure surgical suture comprises the following steps: mixing a developing agent and a first high polymer material to form an inner core material; wherein the difference between the melting point of the developing agent and the melting point of the first high polymer material is less than or equal to 30 DEG C; the inner core material and a second high polymer material are respectively added into corresponding chambers of a double-screw extruder, and are sequentially subjected to extrusion, wire drawing and cooling and setting to obtain the visible core-shell structure surgical suture, which has relatively ideal developing performance and mechanical properties.

Description

Technical Field

[0001] This application relates to the field of radiopaque surgical suture manufacturing technology, and more specifically, to a radiopaque core-shell structure surgical suture, its preparation method, and an occluder. Background Technology

[0002] Surgical sutures have a wide range of clinical applications, including but not limited to suturing various tissues, organs, and blood vessels, as well as weaving medical devices. Currently, most surgical sutures are made from natural or synthetic polymers such as silk, polypropylene, nylon, poly(p-dioxanone), and polylactic-co-glycolic acid copolymer. Compared to metals, these polymers have advantages such as low density, corrosion resistance, and high processability. However, most polymers are not radiopaque under X-rays, which greatly limits the clinical application of polymer sutures and related medical devices.

[0003] Based on this, technicians use a physical mixing method to mix contrast agents and polymer materials to prepare surgical sutures. Although these surgical sutures have contrasting properties, their mechanical properties are too poor (especially when the content of contrast agent is high, such as above 30%), and they cannot meet the requirements of clinical applications. Summary of the Invention

[0004] The purpose of this application is to provide a radiopaque core-shell structure surgical suture, its preparation method, and an occluder, which has both ideal radiopaque performance and mechanical properties.

[0005] The embodiments of this application are implemented as follows:

[0006] In a first aspect, embodiments of this application provide a method for preparing a radiopaque core-shell structured surgical suture, comprising the following steps:

[0007] A contrast agent and a first polymer material are mixed to form a core material; wherein the difference between the melting point of the contrast agent and the melting point of the first polymer material is ≤30℃; the core material and the second polymer material are respectively added to the corresponding chambers of a twin-screw extruder, and then extruded, drawn into fibers and cooled and shaped in sequence to obtain a surgical suture with a visible core-shell structure.

[0008] In the above technical solution, contrast agents and polymer materials with similar melting points are selected as core raw materials for mixing. This allows the contrast agents and polymer materials in the core to form a relatively uniform phase after steps such as mixing, extrusion, and fiber drawing. As a result, the prepared surgical sutures can have both ideal imaging performance and mechanical properties, which is more conducive to clinical application.

[0009] In some alternative embodiments, the melting point of the developer and the melting point of the first polymer material are both in the range of 100 to 300°C; the developer includes at least one of iodofol and iopromide, and the first polymer material includes at least one of polylactic acid and polypropylene.

[0010] In the above technical solutions, based on the selection of developers and polymer materials with relatively similar melting points as core materials, the developers and polymer materials have many possible combinations, which can provide more feasible implementation schemes, thereby facilitating the promotion and application of the technical solutions provided in the embodiments of this application.

[0011] In some alternative embodiments, the melting point of the developer and the melting point of the first polymer material are both in the range of 100 to 300°C; the developer is iodofol, and the first polymer material is polylactic acid with a melting point of 150 to 180°C.

[0012] In the above technical solution, a specific type of contrast agent and a first polymer material are selected and combined to make their physicochemical properties more similar, which helps to improve the mechanical properties of the surgical suture.

[0013] In some alternative embodiments, the developer includes iohexol, and the first polymeric material includes at least one of nylon, polyamide, and polylactic-co-glycolic acid copolymer.

[0014] In the above technical solutions, based on the selection of developers and polymer materials with relatively similar melting points as core materials, the developers and polymer materials have many possible combinations, which can provide more feasible implementation schemes, thereby facilitating the promotion and application of the technical solutions provided in the embodiments of this application.

[0015] In some alternative embodiments, the developer is iohexol, and the first polymeric material is polyamide with a melting point of 230–265°C.

[0016] In the above technical solution, a specific type of contrast agent and a first polymer material are selected and combined to make their physicochemical properties more similar, which helps to improve the mechanical properties of the surgical suture.

[0017] In some alternative implementations, the first polymer material and the second polymer material are made of the same material.

[0018] In the above technical solution, setting the polymer materials in the core and shell to the same form helps the core and shell to bond better, which in turn helps to improve the mechanical properties while taking into account the development performance.

[0019] In some alternative implementations, the first polymer material and the second polymer material have the same physicochemical properties.

[0020] In the above technical solution, setting the polymer materials in the core and shell to have the same physicochemical properties helps the core and shell to bond better, which in turn helps to improve the mechanical properties while taking into account the development performance.

[0021] In some alternative implementations, the developer accounts for 50–95% of the mass of the core material.

[0022] In the above technical solution, the mass ratio of the contrast agent in the core is limited to a specific range. Specifically, the mass of the contrast agent is not less than the mass of the polymer material, so that the surgical suture has better imaging performance.

[0023] In some alternative embodiments, during the extrusion step, the extrusion temperature is T1, the highest melting point of the developer and the first polymer material is T2, T1-T2≤30℃, and the extrusion time is 20-90 min.

[0024] In the above technical solution, the extrusion temperature is limited to a specific range based on the highest melting point, and the extrusion time is also limited to a specific range. This can better maintain the original physical and chemical properties of the material (for example, excessively high temperature will cause the polymer material to age, resulting in a decrease in mechanical properties), thereby making the prepared surgical suture have superior mechanical properties.

[0025] In some alternative embodiments, both the developer and the first polymer material are spherical particles, and the diameter ratio of the developer to the first polymer material is 1:(0.5 to 10).

[0026] In the above technical solution, the particle size ratio of the developing agent and the first polymer material is limited to a specific range, that is, raw materials with relatively similar particle sizes are selected for mixing, so that the developing agent and polymer material in the core can form a relatively uniform phase after steps such as mixing, extrusion and drawing, so that the prepared surgical suture can have both ideal imaging performance and mechanical properties.

[0027] In some alternative embodiments, the diameter ratio of the developer to the first polymer material is 1:1; and / or, the diameters of both the developer and the first polymer material are 1 to 1000 μm.

[0028] In the above technical solution, the particle size ratio of the contrast agent and the first polymer material is limited to a specific value, so that the contrast agent and polymer material in the core can form a more uniform phase after steps such as mixing, extrusion, and fiber drawing. This allows the prepared surgical suture to possess both more ideal imaging performance and mechanical properties. The particle sizes of the contrast agent and polymer material can be selected over a wide range, allowing for customization according to actual needs and providing numerous feasible solutions.

[0029] In some alternative embodiments, during the drawing step, the drawing temperature is lower than the extrusion temperature, and the difference between the drawing temperature and the extrusion temperature is 50–100°C; and / or, the drawing speed is 10–50 m / min.

[0030] In the above technical solution, the temperature of the drawing stage is limited to a specific range based on the temperature of the extrusion stage, which facilitates the drawing of the material (if the temperature is too high, the material has high fluidity and the filaments are easy to break; if the temperature is too low, the material has poor fluidity and is not easy to draw). Furthermore, the drawing speed is limited to a specific range so that the filaments prepared in the drawing stage have better uniformity.

[0031] In some alternative embodiments, in the twin-screw extruder, the outlet diameter of the chamber corresponding to the core material is D1, and the outlet diameter of the chamber corresponding to the second polymer material is D2, with D1 / D2 being 1 / 4 to 2 / 3.

[0032] In the above technical solution, the ratio of the outlet diameter of the corresponding chamber of the core material and the shell material is limited to a specific range so that the core and shell of the prepared surgical suture have a more suitable size ratio in the radial direction, thereby achieving both good imaging performance and mechanical properties.

[0033] Secondly, embodiments of this application provide a radiopaque core-shell structured surgical suture, prepared using the preparation method provided in the first aspect embodiment.

[0034] Thirdly, embodiments of this application provide an occluder made using surgical sutures as provided in the second aspect of the embodiment.

[0035] The beneficial effects of this invention are: selecting contrast agents and polymer materials with relatively close melting points as core raw materials for mixing, so that the contrast agents and polymer materials in the core can form a relatively uniform phase after steps such as mixing, extrusion and drawing, thereby enabling the prepared surgical suture to have both ideal imaging performance and mechanical properties, and thus enabling the prepared occluder to also have both ideal imaging performance and mechanical properties, which is more conducive to the promotion and application of radiopaque surgical sutures in clinical practice. Attached Figure Description

[0036] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0037] Figure 1A process flow diagram illustrating a method for preparing a radiopaque core-shell structured surgical suture, as provided in this application embodiment;

[0038] Figure 2 An X-ray imaging image of a closure device made of a radiopaque core-shell structure surgical suture braid, as provided in Embodiment 1 of this application. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0040] It should be noted that the terms "and / or" in this application, such as "feature 1 and / or feature 2", all refer to the three cases of "feature 1" alone, "feature 2" alone, and "feature 1" plus "feature 2".

[0041] In addition, in the description of this application, unless otherwise stated, "one or more" means two or more; the range of "numerical value a to numerical value b" includes the two endpoints "a" and "b"; and "unit of measurement" in "numerical value a to numerical value b + unit of measurement" represents the "unit of measurement" of both "numerical value a" and "numerical value b".

[0042] The following is a detailed description of a radiopaque core-shell structure surgical suture, its preparation method, and the occluder according to an embodiment of this application.

[0043] In a first aspect, embodiments of this application provide a method for preparing a radiopaque core-shell structured surgical suture, comprising the following steps:

[0044] A contrast agent and a first polymer material are mixed to form a core material; wherein the difference between the melting point of the contrast agent and the melting point of the first polymer material is ≤30℃; the core material and the second polymer material are respectively added to the corresponding chambers of a twin-screw extruder, and then extruded, drawn into fibers and cooled and shaped in sequence to obtain a surgical suture with a visible core-shell structure.

[0045] It should be noted that the second polymer material is the core layer material.

[0046] In this application, contrast agents and polymeric materials with similar melting points are selected as core raw materials for mixing. This allows the contrast agents and polymeric materials in the core to form a relatively uniform phase after steps such as mixing, extrusion, and fiber drawing. As a result, the prepared surgical sutures can have both ideal imaging performance and mechanical properties, which is more conducive to clinical application.

[0047] As an example, the melting point of the developer and the melting point of the first polymer material are both in the range of 100 to 300°C; the developer includes at least one of iodofol and iopromide, and the first polymer material includes at least one of polylactic acid and polypropylene.

[0048] In this embodiment, based on the selection of developers and polymer materials with relatively similar melting points as core materials, the developers and polymer materials have many possible combinations, which can provide more feasible implementation schemes, thereby facilitating the promotion and application of the technical solutions provided in the embodiments of this application.

[0049] As an example, the melting point of the developer and the melting point of the first polymer material are both in the range of 100 to 300°C; the developer is iodofol, and the first polymer material is polylactic acid with a melting point of 150 to 180°C.

[0050] In this embodiment, a specific type of contrast agent and a first polymer material are selected and combined to make their physicochemical properties more similar, which helps to improve the mechanical properties of the surgical suture.

[0051] As an example, the developer includes iohexol, and the first polymeric material includes at least one of nylon, polyamide, and polylactic-co-glycolic acid copolymer.

[0052] In this embodiment, based on the selection of developers and polymer materials with relatively similar melting points as core materials, the developers and polymer materials have many possible combinations, which can provide more feasible implementation schemes, thereby facilitating the promotion and application of the technical solutions provided in the embodiments of this application.

[0053] As an example, the developer is iohexol, and the first polymer material is polyamide with a melting point of 230–265°C.

[0054] In this embodiment, a specific type of contrast agent and a first polymer material are selected and combined to make their physicochemical properties more similar, which helps to improve the mechanical properties of the surgical suture.

[0055] As an example, the first polymer material and the second polymer material are made of the same material.

[0056] In this embodiment, setting the polymer materials in the core and shell to the same form helps the core and shell to bond better, thereby helping to improve mechanical properties while taking into account development performance.

[0057] It should be noted that for polymer materials, the melting point is usually closely related to parameters such as the type of material, degree of polymerization, and crystal structure (fibrous crystals, chain crystals, or extended chain lamellae), which can lead to different melting points for polymer materials of the same material.

[0058] Therefore, when combining developer and polymer materials, after determining the material of the polymer material, special attention should be paid to the actual melting point of the polymer material so that the difference between the melting point of the developer and the melting point of the first polymer material is ≤30℃.

[0059] As an example, the first polymer material and the second polymer material have the same physicochemical properties.

[0060] It should be noted that "the first polymer material and the second polymer material have the same physical and chemical properties" can be understood as the two materials being the same model from the same manufacturer, meaning that their material types, degree of polymerization, and crystal structure parameters are all the same.

[0061] In this embodiment, setting the polymer materials in the core and shell to have the same physicochemical properties helps the core and shell to bond better, which in turn helps to improve the mechanical properties while taking into account the development performance.

[0062] In other possible implementations, the first polymer material and the second polymer material may also be selected from different materials.

[0063] Understandably, the mass percentage of developer in the kernel is not limited and can be adjusted according to actual needs.

[0064] As an example, the developer accounts for 50% to 95% of the mass of the core material, such as, but not limited to, any one of 50%, 60%, 70%, 80%, 90%, and 95% or any range between two.

[0065] In this embodiment, the mass ratio of the contrast agent in the core is limited to a specific range. Specifically, the mass of the contrast agent is not less than the mass of the polymer material, so that the surgical suture has superior contrast performance.

[0066] As an example, in the extrusion step, the extrusion temperature is T1, the highest melting point of the developer and the first polymer material is T2, T1-T2≤30℃, and the extrusion time is 20 to 90 min, for example, but not limited to any one of 20 min, 30 min, 40 min, 50 min, 60 min, 70 min, 80 min and 90 min or any range between two.

[0067] In this embodiment, the extrusion temperature is limited to a specific range based on the highest melting point, and the extrusion time is also limited to a specific range. This can better maintain the original physical and chemical properties of the material (for example, excessively high temperatures can cause the polymer material to age, leading to a decrease in mechanical properties), thereby making the prepared surgical sutures have superior mechanical properties.

[0068] As an example, both the developer and the first polymer material are spherical particles, and the diameter ratio of the developer and the first polymer material is 1:(0.5 to 10), for example, but not limited to any one of the diameter ratios of 0.5:2, 0.5:4, 0.5:6, 0.5:8 and 0.5:10, or any range between the two.

[0069] In this embodiment, the particle size ratio of the developer and the first polymer material is limited to a specific range, that is, raw materials with relatively similar particle sizes are selected for mixing, so that the developer and polymer material in the core can be well integrated and compounded together after steps such as mixing, extrusion and drawing, so that the prepared surgical suture can have both ideal imaging performance and mechanical properties.

[0070] As an example, both the developer and the first polymer material are spherical particles, and the diameter ratio of the developer to the first polymer material is 1:1.

[0071] In this embodiment, the particle size ratio of the developer and the first polymer material is limited to a specific value so that the developer and polymer material in the core can form a more uniform phase after steps such as mixing, extrusion and drawing, thereby enabling the prepared surgical suture to have both more ideal imaging performance and mechanical properties.

[0072] As an example, the diameters of the developer and the first polymer material are both 1 to 1000 μm, for example, but not limited to, any point value or a range between any two of the diameters of 1 μm, 50 μm, 100 μm, 200 μm, 300 μm, 400 μm, 500 μm, 600 μm, 700 μm, 800 μm, 900 μm and 1000 μm.

[0073] In this embodiment, the particle size of the developer and polymer material can be selected from a wide range, and can be set according to actual needs, providing a variety of feasible implementation schemes.

[0074] As an example, in the drawing step, the drawing temperature is lower than the extrusion temperature, and the difference between the drawing temperature and the extrusion temperature is 50 to 100°C, for example, but not limited to, a difference of any one of 50°C, 60°C, 70°C, 80°C, 90°C and 100°C or a range between any two.

[0075] In this embodiment, the temperature of the drawing stage is limited to a specific range based on the temperature of the extrusion stage, which facilitates the drawing of the material (if the temperature is too high, the material has high fluidity and the filaments are easy to break; if the temperature is too low, the material has poor fluidity and it is not easy to draw the filaments).

[0076] As an example, the wire drawing speed is 10 to 50 m / min, such as, but not limited to, any one of the wire drawing speeds of 10 m / min, 20 m / min, 30 m / min, 40 m / min and 50 m / min or any range between two of them.

[0077] In this embodiment, the drawing speed is further limited to a specific range so that the filament bundles prepared during the drawing stage have better uniformity.

[0078] As an example, in a twin-screw extruder, the outlet diameter of the chamber corresponding to the core material is D1, and the outlet diameter of the chamber corresponding to the second polymer material is D2, with D1 / D2 being 1 / 4 to 2 / 3.

[0079] In this embodiment, the ratio of the outlet diameter of the corresponding chamber to the core material and the shell material is limited to a specific range so that the core and shell of the prepared surgical suture have a more suitable size ratio in the radial direction, thereby achieving both good imaging performance and mechanical properties.

[0080] It should be noted that, for the preparation of surgical sutures, any processes or steps not specifically described or limited can be set according to conventional methods in this field.

[0081] As an example, in the step of mixing the developer and the first polymer material, the mixing time is 5 to 20 minutes, for example, but not limited to any one of 5 minutes, 10 minutes, 15 minutes and 20 minutes or any range between two; the stirring speed is 400 to 600 rpm, for example, but not limited to any one of 400 rpm, 450 rpm, 500 rpm, 550 rpm and 600 rpm or any range between two; the specific parameters can be adjusted according to the actual amount of material.

[0082] As an example, in the extrusion step, the extrusion pressure is 2 to 5 MPa, for example, but not limited to any one of 2 MPa, 3 MPa, 4 MPa and 5 MPa or any range between two.

[0083] As an example, a process flow diagram of a method for preparing a radiopaque core-shell surgical suture is exemplarily provided. Figure 1 .

[0084] Secondly, embodiments of this application provide a radiopaque core-shell structured surgical suture, prepared using the preparation method provided in the first aspect embodiment.

[0085] In this application, the surgical suture is prepared using the preparation method provided in the first aspect embodiment. Because it uses a contrast agent and a polymer material with similar physicochemical properties, it can have both superior contrast performance and mechanical properties.

[0086] As an example, the diameter of the surgical suture is 0.02 to 0.7 mm, such as, but not limited to, any one of the diameters of 0.02 mm, 0.01 mm, 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm and 0.7 mm or any range between two of them; the specific parameters can be adjusted according to the actual amount of material.

[0087] In this embodiment, the diameter of the surgical suture is limited to a specific range, which makes it easier to use in clinical practice.

[0088] Thirdly, embodiments of this application provide an occluder made using surgical sutures as provided in the second aspect of the embodiment.

[0089] The features and performance of this application will be further described in detail below with reference to the embodiments.

[0090] Example 1

[0091] This application provides a method for preparing a radiopaque core-shell structured surgical suture, comprising the following steps:

[0092] Polylactic acid (specific model number) with a particle size of 20 μm was used. PL 38 (melting point 180℃) and iodofol (melting point 178℃) were mixed at a mass ratio of 1:4 to obtain the core material. The mixing time was 10 min and the stirring speed was 500 rpm.

[0093] The aforementioned core material and polylactic acid (i.e., the second polymer material is the same as the first polymer material) are added to the corresponding chambers of a twin-screw extruder, and then sequentially extruded, drawn, and cooled to obtain a radiopaque core-shell structured surgical suture. The ratio of the outlet diameter D1 of the chamber corresponding to the core material to the outlet diameter D2 of the chamber corresponding to the second polymer material is 1 / 2. In the extrusion step, the extrusion temperature is 200℃, the extrusion pressure is 3MPa, and the extrusion time is 40min. In the drawing step, the drawing temperature is 120℃, and the drawing speed is 15m / min.

[0094] Example 2

[0095] This application provides a method for preparing a radiopaque core-shell structured surgical suture, comprising the following steps:

[0096] Polyamide (specifically model HiDura) with a particle size of 40 μm was used. TM MED AP NT0860 (melting point 260℃) and iohexol (melting point 255℃) were mixed at a mass ratio of 1:5 to obtain the core material. The mixing time was 10 min and the stirring speed was 500 rpm.

[0097] The aforementioned core material and polyamide (i.e., the second polymer material is the same as the first polymer material) are added to the corresponding chambers of a twin-screw extruder, and then sequentially extruded, drawn, and cooled to obtain a radiopaque core-shell structured surgical suture. The ratio of the outlet diameter D1 of the chamber corresponding to the core material to the outlet diameter D2 of the chamber corresponding to the second polymer material is 1 / 2. In the extrusion step, the extrusion temperature is 270℃, the extrusion pressure is 3MPa, and the extrusion time is 40min. In the drawing step, the drawing temperature is 180℃, and the drawing speed is 40m / min.

[0098] Example 3

[0099] This application provides a method for preparing a radiopaque core-shell structured surgical suture, which differs from Example 1 only in that: polylactic acid with a particle size of 0.1 mm and iodofol with a particle size of 5 μm are mixed at a mass ratio of 1:4 to obtain the core material.

[0100] Example 4

[0101] This application provides a method for preparing a radiopaque core-shell structured surgical suture, which differs from Example 1 only in that the extrusion temperature is 240°C in the extrusion step.

[0102] Comparative Example 1

[0103] This application provides a comparative example of a method for preparing a radiopaque core-shell structured surgical suture, which differs from Example 2 only in that: polyamide (specifically HiDura) with a particle size of 40 μm is used. TM MED AP NT0860 (melting point 260℃) and iodofol (melting point 178℃) were mixed at a mass ratio of 1:4 to obtain the core material.

[0104] Comparative Example 2

[0105] This application provides a comparative example of a method for preparing a radiopaque core-shell structured surgical suture, the only difference from Example 1 being: the suture used in Example 1 (specifically, the model number is...) is... PL 38 (melting point 180℃) polylactic acid is replaced with (specific model Ingeo)TM Biopolymer 2500HP (melting point 210℃) polylactic acid, which is the first polymer material with the same material type but different melting points; correspondingly, the extrusion temperature is 230℃ and the fiber drawing temperature is 130℃.

[0106] To better understand the parameter differences between the various embodiments and comparative examples, some important parameters are summarized and explained in the form of a table.

[0107] Table 1. Parameter statistics for each embodiment and comparative example.

[0108]

[0109] Experimental Example 1

[0110] Mechanical property testing of surgical sutures

[0111] Test method:

[0112] The surgical sutures prepared in Examples 1-4 and Comparative Examples 1-2 were numbered, and then the mechanical properties of each sample were tested.

[0113] Table 2. Statistical table of mechanical properties of various embodiments and comparative examples.

[0114] sample Fracture stress / MPa Elongation at break / % Example 1 320 8 Example 2 450 18 Example 3 285 6 Example 4 270 5 Comparative Example 1 180 3 Comparative Example 2 215 4

[0115] Referring to Table 2, the test results of Examples 1-2 and Comparative Example 1 show that using a contrast agent and polymer material with similar melting points as the core material results in surgical sutures with superior mechanical properties compared to those using contrast agents and polymer materials with significantly different melting points. Since the imaging performance of the surgical suture is mainly related to the mass ratio of the contrast agent, when the amount of contrast agent is constant and within a high range, the imaging performance of both is similar and relatively good, but the mechanical properties of Example 1 are superior. The test results of Examples 1 and 3 show that, based on the relatively similar melting points of the contrast agent and the first polymer material, further using a contrast agent and polymer material with similar particle sizes as the core material also helps to improve the mechanical properties of the prepared surgical suture.

[0116] As can be seen from the test results of Examples 1 and 4, when the melting points of the contrast agent and the first polymer material are relatively close, further limiting the processing temperature of the extrusion step within a specific range also helps to improve the mechanical properties of the prepared surgical suture.

[0117] As can be seen from the test results of Example 1 and Comparative Example 2, when combining the contrast agent and the polymer material, after determining the material of the polymer material, special attention should be paid to the actual melting point of the polymer material so that the melting point of the contrast agent and the melting point of the first polymer material are relatively close, which helps to improve the mechanical properties of the prepared surgical suture.

[0118] Experimental Example 2

[0119] Visualization performance test of surgical sutures

[0120] Test method:

[0121] The surgical suture from Example 1 was braided into a rivetless occluder. Specifically, one end of the surgical suture prepared in Example 1 was fixed to a cylindrical mold, and then the suture was passed around the fixing element on the mold 3-5 times to obtain a cylindrical mesh. The two ends of the mesh were pressed towards each other and heated to shape it into a disc-shaped occluder. Then, the X-ray imaging performance was observed under a digital subtraction angiography (DSA) machine, where the DSA parameters were: tube voltage 80kV, tube current 2mA, and sample distance 40cm.

[0122] See Figure 2 As can be seen, the surgical suture prepared in Example 1 of this application can be clearly displayed under an angiography machine, proving that it has excellent imaging performance.

[0123] In summary, the test results of Examples 1 and 2 show that the surgical sutures prepared using the preparation process provided in this application have both ideal imaging performance and mechanical properties.

[0124] The embodiments described above are some, but not all, of the embodiments of this application. The detailed description of the embodiments of this application is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

Claims

1. A method for preparing a radiopaque core-shell surgical suture, characterized in that, Includes the following steps: A developer and a first polymer material are mixed to form a core material; wherein the difference between the melting point of the developer and the melting point of the first polymer material is ≤30℃; and the developer accounts for 70~95% of the mass of the core material. The core material and the second polymer material are respectively added to the corresponding chambers of a twin-screw extruder, and then extruded, drawn, and cooled to obtain a radiopaque core-shell structured surgical suture.

2. The method for preparing surgical sutures according to claim 1, characterized in that, The melting point of the developer and the melting point of the first polymer material are both in the range of 100~300°C; the developer includes at least one of iodofol and iopromide, and the first polymer material includes at least one of polylactic acid and polypropylene.

3. The method for preparing surgical sutures according to claim 2, characterized in that, The developer is iodofol, and the first polymer material is polylactic acid with a melting point of 150~180℃.

4. The method for preparing surgical sutures according to claim 1, characterized in that, The melting point of the developer and the melting point of the first polymer material are both in the range of 100~300°C; the developer includes iohexol, and the first polymer material includes at least one of nylon, polyamide and polylactic acid-glycolic acid copolymer.

5. The method for preparing surgical sutures according to claim 4, characterized in that, The developer is iohexol, and the first polymer material is polyamide with a melting point of 230~265℃.

6. The method for preparing surgical sutures according to claim 1, characterized in that, The first polymer material and the second polymer material are made of the same material.

7. The method for preparing surgical sutures according to claim 6, characterized in that, The first polymer material and the second polymer material have the same physicochemical properties.

8. A method for preparing surgical sutures according to any one of claims 1 to 7, characterized in that, In the extrusion step, the extrusion temperature is T1, the highest melting point of the developer and the first polymer material is T2, T1-T2≤30℃, and the extrusion time is 20~90 min.

9. The method for preparing surgical sutures according to any one of claims 1 to 7, characterized in that, Both the developer and the first polymer material are spherical particles, and the diameter ratio of the developer to the first polymer material is 1:(0.5~10).

10. The method for preparing surgical sutures according to claim 9, characterized in that, The diameter ratio of the developer to the first polymer material is 1:1; and / or, the diameters of the developer and the first polymer material are both 1~1000 μm.

11. The method for preparing surgical sutures according to claim 8, characterized in that, In the fiber drawing step, the fiber drawing temperature is lower than the extrusion temperature, and the difference between the fiber drawing temperature and the extrusion temperature is 50~100℃; and / or, the fiber drawing speed is 10~50 m / min.

12. The method for preparing surgical sutures according to any one of claims 1 to 7, characterized in that, In the twin-screw extruder, the outlet diameter of the chamber corresponding to the core material is D1, and the outlet diameter of the chamber corresponding to the second polymer material is D2, with D1 / D2 being 1 / 4 to 2 / 3.

13. A radiopaque surgical suture with a core-shell structure, characterized in that, It is prepared by any one of the preparation methods described in claims 1 to 12.

14. A sealing device, characterized in that, It is made using the surgical suture as described in claim 13.

Images