Method for manufacturing medical suture

Abstract

An embodiment of the present invention provides a method for manufacturing a medical suture, the method comprising: a step (S100) of applying a central thread extending in one direction to an overflow mold so as to form fine protrusions on the outer circumferential surface of the central thread within a range higher than the glass transition temperature (Tg) and lower than its melting point (Tm); and a step (S200) of forming a mesh on the central thread by wrapping the central thread while applying a predetermined tensile force to each of a plurality of fine threads.

Description

Method for manufacturing medical sutures

[0001] The present invention relates to a method for manufacturing medical sutures.

[0002] Sutures are used not only to connect or close various damaged areas of animal tissue and surgical incisions, but also for cosmetic purposes such as tissue lifting procedures like facial lifts.

[0003] Conventional sutures are broadly classified into absorbable sutures made of materials that decompose within the body and non-absorbable sutures made of materials that do not decompose, and are used appropriately depending on the purpose, site of use, and application. However, conventional sutures, which are smooth cylindrical in shape, have weak fixation to tissues, a very high Young's modulus, and low elongation, so if they are not fixed, they can easily be exposed to the outside or detach from the surgical site.

[0004] To improve this, manufacturing methods have begun to emerge that process the shape of existing sutures into various forms. For example, there are forms such as barbed sutures created by cutting the suture to form barbs, sutures with improved fixation strength created by processing the raw material into an intaglio using ultrasound, sutures formed into barbs by flattening a cylindrical suture with a press and then cutting it with equipment such as a puncher to facilitate processing, and sutures formed into barbs by molding with an extrusion mold.

[0005] Recently, formulations such as Fig. 1, in which a mesh is wrapped around a core thread for additional functionality, have emerged. This formulation is manufactured by attaching a mesh made of mandrel to a core thread, but a problem occurred where the protrusions formed on the core thread bent during the process of attaching the mesh to the core thread. In addition, the above formulation had a problem in that a gap occurred between the mesh and the core thread, weakening the fixation force with the tissue, and the volume increased, making it difficult to insert into a cannula.

[0006] The present invention aims to solve the problems of the aforementioned prior art, and the objective of the present invention is to provide a method for manufacturing a medical suture that effectively reduces the overall volume and improves fixation strength.

[0007] One aspect of the present invention provides a method for manufacturing a medical suture, comprising the steps of: applying a central thread extending in one direction to an outflow mold to form micro-protrusions on the outer surface of the central thread in a range higher than the glass transition temperature (Tg) and lower than the melting point (Tm) (S100); and wrapping the central thread while applying a predetermined tensile force to each of a plurality of micro-threads to form a mesh on the central thread (S200).

[0008] In one embodiment, in the step (S200) of forming a mesh on the center thread, the predetermined tensile force may be 20gf or more and 240gf or less.

[0009] In one embodiment, the mesh may come into contact with the outer surface of the center chamber.

[0010] In one embodiment, the mesh may be composed of 4 or more and 16 or fewer micro-chambers.

[0011] In one embodiment, the diameter of the micro-thread may be 0.05 mm or more and 0.199 mm or less.

[0012] In one embodiment, the micro-protrusions may protrude outside the mesh.

[0013] In one embodiment, the medical suture may be made of a bioabsorbable medical polymer material selected from polydioxanone, polylactic acid, polyglycolic acid, polycaprolactone, polyhydroxyalkanoates, and copolymers thereof.

[0014] In one embodiment, the medical suture may be made of a bio-nonabsorbable medical polymer material selected from polypropylene, nylon, and mixtures thereof.

[0015] A medical suture according to one aspect of the present invention is formed such that a mesh surrounds a central thread and abuts against the central thread, thereby reducing the overall volume and significantly improving tensile strength and fixation strength compared to conventional medical sutures.

[0016] In addition, the method for manufacturing a medical suture according to one aspect of the present invention has the characteristic of improving productivity and minimizing contamination and discoloration compared to the existing manufacturing method in which a mesh is manufactured using a mandrel and then bonded to a central thread.

[0017] The effects of the present invention are not limited to the effects described above, and should be understood to include all effects that can be inferred from the configuration of the invention described in the detailed description or claims of the present invention.

[0018] Figure 1 is a conventional medical suture.

[0019] FIG. 2 is a medical suture according to one embodiment of the present invention.

[0020] FIG. 3 is a step diagram showing a method for manufacturing a medical suture according to one embodiment of the present invention.

[0021] Figure 4 is a graph showing the results of comparing the fixation strength of a medical suture according to one embodiment of the present invention and a medical suture of Comparative Example 2.

[0022] Figure 5 is a graph showing the results of comparing the tensile strength of a medical suture according to one embodiment of the present invention and a medical suture of Comparative Example 4.

[0023] The present invention will be described below with reference to the attached drawings. However, the present invention may be implemented in various different forms and is therefore not limited to the embodiments described herein. Furthermore, in order to clearly explain the present invention in the drawings, parts unrelated to the explanation have been omitted, and similar parts throughout the specification have been given similar reference numerals.

[0024] Throughout the specification, when it is stated that a part is "connected" to another part, this includes not only cases where they are "directly connected," but also cases where they are "indirectly connected" with other members interposed between them. Furthermore, when it is stated that a part "includes" a certain component, this means that, unless specifically stated otherwise, it does not exclude other components but rather allows for the inclusion of additional components.

[0025] Terms including ordinal numbers such as ‘first’ or ‘second’ used herein may be used to describe various components or steps, but such components or steps should not be limited by ordinal numbers. Terms including ordinal numbers should be interpreted solely for the purpose of distinguishing one component or step from other components or steps.

[0026] The medical suture of the present invention is used not only to connect or suture various damaged areas of animal tissues such as skin, muscles, tendons, internal organs, bone tissue, nerves, and blood vessels, as well as incision sites resulting from surgical procedures, but can also be used for cosmetic purposes such as tissue lifting procedures like facial lifting.

[0027] The medical suture of the present invention can be manufactured from a single-strand polymer. Specifically, for example, the medical suture can be manufactured from a bioabsorbable medical polymer composed of one or more of polydioxanone, monocryl, polycaprolactone, polyglycolic acid, polylactic acid, poly(lactic-co-glycolic acid), poly(lactide-co-caprolactone), and polyhydroxyalkanoates.

[0028] In addition, the medical suture of the present invention may be manufactured from a non-absorbable medical polymer composed of one or more of polypropylene, nylon, and polytetrafluoroethylene.

[0029] The medical suture of the present invention is not limited to a specific material, and it goes without saying that all polymers can be applied.

[0030] FIG. 2 is a medical suture according to one embodiment of the present invention.

[0031] A medical suture (1) according to one embodiment of the present invention includes a central thread (10) extending in one direction, a micro-protrusion (20), and a mesh (30).

[0032] The center chamber (10) can be formed into a linear structure including elasticity, and the micro-protrusions (20) can be formed on the outer surface of the center chamber (10).

[0033] The micro-protrusion (20) is a protrusion shape formed around the central thread (10) and can be formed in a direction inclined to the direction in which the central thread (10) extends. The micro-protrusion (20) can be implemented as a barb or the like, but is not necessarily limited thereto. Here, a barb refers to a hook shape resembling a barb, such as a fishing hook.

[0034] The mesh (30) is composed of a plurality of alternating micro-threads (31). As the plurality of micro-threads (31) are arranged to intersect each other, a grid-shaped space (32) is formed between the micro-threads (31), and the micro-protrusions (20) protrude to the outside of the mesh (30) through the space (32).

[0035] The mesh (30) is formed to surround the center thread (10) and come into contact with the center thread (10). Specifically, a portion of the micro-thread (31) is positioned in contact with the center thread (10).

[0036] More specifically, the mesh (30) extends along the longitudinal axis of the center thread (10), and the entire area of ​​the mesh (30) is formed to substantially contact the center thread (10).

[0037] Accordingly, the maximum radius from the axis of the center thread (10) to the mesh (30) can be formed to be smaller than the maximum radius from the axis of the center thread (10) to the micro-protrusion (20). Here, the radius refers to the radial length with respect to the axis of the center thread (10).

[0038] The mesh (30) is composed of a plurality of alternating micro-threads (31). As the plurality of micro-threads (31) are arranged to intersect each other, a grid-shaped space (32) is formed between the micro-threads (31), and the micro-protrusions (20) protrude to the outside of the mesh (30) through the space (32).

[0039] The mesh (30) is formed to surround the center thread (10) and to be in contact with the center thread (10). In detail, a portion of the micro-thread (31) is positioned in contact with the center thread (10). More specifically, the mesh (30) extends along the longitudinal axis of the center thread (10), and the entire area of ​​the mesh (30) is formed to be in contact with the center thread (10).

[0040] Accordingly, the maximum radius from the axis of the center thread (10) to the mesh (30) can be formed to be smaller than the maximum radius from the axis of the center thread (10) to the micro-protrusion (20). Here, the diameter refers to the radial length with respect to the axis of the center thread (10).

[0041] In one embodiment, the mesh (30) may be composed of 4 or more and 16 or fewer fine threads (31).

[0042] In one embodiment, the diameter of the micro-thread (31) may be formed to be 0.05 mm or more and 0.199 mm or less.

[0043]

[0044] Referring to FIG. 3, a method for manufacturing a medical suture according to one embodiment of the present invention comprises the step (S100) of forming micro-protrusions on the outer surface of the central thread in a range higher than the glass transition temperature (Tg) and lower than the melting point (Tm) by applying a central thread extending in one direction to an outflow mold, and the step (S200) of forming a mesh on the central thread by wrapping the central thread while applying a predetermined tensile force to each of the plurality of micro-threads.

[0045] Specifically, in the step (S100) of forming micro-protrusions, the applied temperature is a specific temperature within the range of the melting point of the suture material to the glass transition temperature, and preferably 15°C (Tm-15°C) below the melting point to 30°C (Tm-30°C) below the melting point.

[0046] The magnitude of the pressure applied to the extrusion mold may be in the range of 10 to 200 kgf / ㎠, preferably in the range of 80 to 180 kgf / ㎠. If the magnitude of the pressure is less than the above range, the burr is not removed by the extrusion mold, and it tends to be difficult to process into a medical suture, and if the pressure is greater than the above range, the durability of the extrusion mold may be weakened.

[0047] In the step (S200) of forming a mesh on the center thread, the predetermined tensile force applied to each fine thread is 20gf or more and 320gf or less. Preferably, the predetermined tensile force applied to each fine thread is 20gf or more and 240gf or less.

[0048] In the medical suture of the present invention, stress distribution is easily achieved through the embossed micro-protrusions formed on the central thread in step S100, so even if a load is applied to the micro-protrusions during the mesh formation process, the micro-protrusions do not easily bend.

[0049] In contrast, conventional medical sutures that form micro-protrusions by cutting a portion of the central thread have stress concentrated at the connection points of the micro-protrusions, causing the protrusions to easily bend.

[0050] Due to these structural differences, the medical suture of the present invention provides higher durability and stability compared to the prior art.

[0051] In addition, according to the method for manufacturing a medical suture according to one embodiment of the present invention, since the mesh is directly woven onto the central thread in the step (S200) of forming a mesh on the central thread, the manufacturing step of joining the manufactured mesh to the central thread having micro-protrusions is omitted, so the manufacturing time is drastically reduced compared to the conventional manufacturing method and productivity can be greatly improved.

[0052] In addition, by applying a predetermined tensile force to the micro-thread while manufacturing a mesh on the central thread, the mesh comes into contact with the central thread, and the overall volume of the mesh can be reduced. That is, since the overall volume of the medical suture is reduced, insertion of the medical suture into the cannula becomes easier, thereby improving the surgical feasibility of the medical suture.

[0053] In addition, since the mesh adheres closely to the center thread, the fixation strength of the medical suture can be improved.

[0054] The embodiments of this specification will be described in more detail below. However, the following experimental results represent only representative results among the above embodiments, and the scope and content of this specification should not be interpreted as being narrowed or limited by the embodiments. The respective effects of various embodiments of this specification not explicitly presented below will be described in detail in the relevant sections.

[0055]

[0056] Examples 1 to 14

[0057] A central thread formed of polydioxanone material and extending in one direction was applied to an outflow mold with protrusions, and micro-protrusions were formed on the outer surface of the central thread within a range higher than the glass transition temperature (Tg) and lower than the melting point (Tm). In addition, a medical suture according to the example was manufactured by wrapping the central thread while applying tensile force according to the table below to each micro-thread so that the mesh adheres to the central thread.

[0058]

[0059] Tensile force applied to the strands of the fine thread Example 1420gf Example 2820gf Example 31620gf Example 4480gf Example 5880gf Example 61680gf Example 74160gf Example 88160gf Example 916160gf Example 104240gf Example 118240gf Example 1216240gf Example 134320gf Example 148320gf

[0060] Comparative Examples 1 to 3

[0061] Micro-protrusions were formed on the central thread in the same manner as in the example, and a medical suture was manufactured by combining a mesh produced by a mandrel with the central thread.

[0062]

[0063] Tensile force applied to the strands of the fine thread Comparative Example 140gf Comparative Example 280gf Comparative Example 3160gf

[0064] Comparative Examples 4 and 5

[0065] A medical suture was manufactured in the same manner as in the example, except for the tensile force applied to the micro-thread.

[0066]

[0067] Tensile force applied to the strands of the fine thread Comparative Example 48,400gf Comparative Example 54,480gf

[0068] Experimental Example 1: Appearance Comparison

[0069] The external appearance of medical sutures manufactured according to the examples and comparative examples was compared, and the results are as shown in Table 4 and Figures 1 and 2 below.

[0070]

[0071] Classification | External Appearance | Comparison Example 1 | Mesh in close contact with center thread | Example 2 | Mesh in close contact with center thread | Example 3 | Mesh in close contact with center thread | Example 4 | Mesh in close contact with center thread | Example 5 | Mesh in close contact with center thread | Example 6 | Mesh in close contact with center thread | Example 7 | Mesh in close contact with center thread | Example 8 | Mesh in close contact with center thread | Example 9 | Mesh in close contact with center thread | Example 10 | Mesh in close contact with center thread | Example 11 | Mesh in close contact with center thread | Example 12 | Mesh in close contact with center thread | Example 13 | Mesh in close contact with center thread | Example 14 | Mesh in close contact with center thread | Comparison Example 1 | Mesh separated from center thread | Comparison Example 2 | Mesh separated from center thread | Comparison Example 3 | Mesh separated from center thread | Comparison Example 4 | Center thread bent | Comparison Example 5 | Center thread bent

[0072] The medical sutures according to Examples 1 to 14 have their overall volume reduced as the mesh is closely attached to the central thread as shown in FIG. 2.

[0073] In the medical sutures according to Comparative Examples 1 to 3, the mesh is spaced apart from the central thread as shown in FIG. 1. That is, in the medical sutures according to Comparative Examples 1 to 3, the maximum radius from the axis of the central thread to the mesh is formed to be larger than the maximum radius from the axis of the central thread to the micro-protrusion.

[0074] In Comparative Examples 4 and 5, structural damage occurred because the center thread could not withstand the tension due to excessive tensile force (400gf or more) applied to the micro-thread.

[0075]

[0076] Experimental Example 2: Measurement of fixation strength of medical sutures

[0077] Fixation strength was measured using the fixation strength test medium specified in the Korean Ministry of Food and Drug Safety’s Guidelines for Performance Evaluation of Facial Tissue Fixation Threads (MFDS).

[0078] Specifically, the fixation test medium consists of a three-layer structure comprising an upper layer silicone, a middle layer composed of gauze, and a lower layer silicone. A medical suture of Comparative Example 2 or Example 2 was inserted parallel to the middle layer (gauze) of the fixation test medium by approximately 10 cm, and the fixation test medium inserted between the medical sutures and the end of the medical suture were each fixed to the top and bottom of a clamp. Subsequently, the clamp was driven at a predetermined speed to pull the medical suture and extract it from the fixation test medium, and the force against the displacement of the medical suture was measured. The results are shown in FIG. 4 and Table 5 below.

[0079]

[0080] Classification Fixing Strength (N) Example 2 23.79 ± 2.54 Comparative Example 2 20.54 ± 1.50

[0081] Referring to Figure 4 and Table 5, it was confirmed that the fixation strength of the medical suture of Example 2 was improved by approximately 15% compared to the medical suture of Comparative Example 2. This is the result of minimizing displacement within the tissue when the suture is pulled after being inserted into the tissue, because the mesh adheres closely to the central thread.

[0082] In addition, in Comparative Example 2, the mesh and the central thread were separated, so the volume of the mesh was formed large, which meant that only a cannula with a large diameter could be used when implanting the suture, resulting in limited use depending on the surgical site and the patient's condition. On the other hand, in Example 2, the mesh was closely attached to the central thread, reducing the overall volume of the medical suture, and thus, it was possible to implant the suture by combining it with a cannula with a small diameter.

[0083]

[0084] Experimental Example 3: Measurement of Tensile Strength of Medical Sutures

[0085] Tensile strength is USP 43-NF38 of the U.S. Food and Drug Administration <881> Tensile Strength was measured. Specifically, medical sutures of Examples 2, 5, 8, 11, 14 and Comparative Example 4, each having 8 strands of fine thread, were fixed to the top and bottom of the clamp. The gauge distance between the clamps was set to 40 mm, and the driving speed of the clamps was set to 80 mm / min. Tensile strength was measured at the point where the medical sutures broke, and the results are as shown in Fig. 5 and the table below.

[0086] Referring to FIG. 5 and Table 6 below, it was confirmed that the tensile strength of the medical suture of the example, in which the tensile force applied to the micro-thread is 20gf to 320gf, is significantly improved compared to the medical suture of Comparative Example 4, in which the tensile force applied to the micro-thread is 400gf.

[0087]

[0088] Classification Tensile Strength (N) Example 243.77 ± 3.43 Example 540.85 ± 4.12 Example 843.49 ± 0.53 Example 1142.01 ± 2.45 Example 1439.19 ± 3.80 Comparative Example 435.29 ± 3.26

[0089] In conclusion, the method for manufacturing a medical suture according to one embodiment of the present invention has the characteristic of improving productivity and minimizing contamination and discoloration compared to the existing manufacturing method in which a mesh is manufactured using a mandrel and then bonded to a central thread.

[0090] In addition, the medical suture manufactured according to the method for manufacturing a medical suture of one embodiment of the present invention has a mesh that adheres closely to the central thread, thereby reducing the overall volume, and furthermore, the tensile strength and fixation force are significantly improved compared to conventional medical sutures.

[0091] The foregoing description of the present invention is for illustrative purposes only, and those skilled in the art will understand that other specific forms can be easily modified without altering the technical spirit or essential features of the present invention. Therefore, the embodiments described above should be understood as illustrative in all respects and not restrictive. For example, each component described as a single unit may be implemented in a distributed manner, and components described as distributed may likewise be implemented in a combined form.

[0092] The scope of the present invention is defined by the claims set forth below, and all modifications or variations derived from the meaning and scope of the claims and equivalent concepts thereof should be interpreted as being included within the scope of the present invention.

[0093]

[0094] [Explanation of the symbol]

[0095] 1 medical suture

[0096] 10 Central Room

[0097] 20 micro-protrusions

[0098] 30 mesh

Claims

1. A step (S100) in which a central thread extending in one direction is applied to an outflow mold to form micro-protrusions on the outer surface of the central thread in a range higher than the glass transition temperature (Tg) and lower than the melting point (Tm); and A method for manufacturing a medical suture, characterized by including the step (S200) of wrapping a central thread while applying a predetermined tensile force to each of a plurality of micro-threads to form a mesh on the central thread.

2. In Paragraph 1, In the step (S200) of forming a mesh on the central thread, A method for manufacturing a medical suture, characterized in that the above-mentioned predetermined tensile strength is 20gf or more and 240gf or less.

3. In Paragraph 1, A method for manufacturing a medical suture, characterized in that the above mesh is in contact with the outer surface of the above central thread.

4. In Paragraph 1, A method for manufacturing a medical suture, characterized in that the mesh is composed of 4 or more and 16 or fewer fine threads.

5. In Paragraph 1, A method for manufacturing a medical suture, characterized in that the diameter of the micro-thread is 0.05 mm or more and 0.199 mm or less.

6. In Paragraph 1, A method for manufacturing a medical suture, characterized in that the above-mentioned micro-protrusions protrude outside the mesh.

7. In Paragraph 1, The above medical suture is, A method for manufacturing a medical suture, characterized by being composed of a bioabsorbable medical polymer material selected from polydioxanone, polylactic acid, polyglycolic acid, polycaprolactone, polyhydroxyalkanoates, and copolymers thereof.

8. In Paragraph 1, The above medical suture is, A method for manufacturing a medical suture, characterized by being made of a bio-nonabsorbable medical polymer material selected from polypropylene, nylon, and mixtures thereof.

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