Medical suture and manufacturing method therefor

Abstract

One embodiment of the present invention provides a medical suture comprising: a suture body that extends in one direction and is twisted; and micro-cogs formed on the outer surface of the suture body and disposed in a three-dimensional structure along the circumference of the suture body, wherein, in the suture body, the length in one direction of a region having a rotation angle of 180 degrees at both ends is denoted as twist pitch n and, when each of n1 and n2 denotes n of the suture body before and after the formation of the micro-cogs, n1 is less than n2.

Description

Medical suture and method for manufacturing the same

[0001] The present invention relates to a medical suture and a method for manufacturing the same.

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

[0003] Conventional sutures are broadly categorized into absorbable sutures made of materials that break down in the body and non-absorbable sutures made of materials that do not. These are used appropriately depending on the intended use, site of application, and intended use. However, existing sutures, which are smooth, cylindrical in shape, have weak fixation to tissue, a very high Young's modulus, and low elongation. This can lead to exposure to the outside or dislocation from the surgical site if not properly fixed.

[0004] Recently, to improve this, manufacturing methods that process existing sutures into various shapes have emerged. Examples include barbed sutures, which create barbs by cutting the suture, sutures with enhanced fixation by engraving the yarn with ultrasound, sutures where barbs are formed by pressing cylindrical sutures flat with a press and then cutting them with equipment such as a puncher to create barbs for ease of processing, and sutures where barbs are formed by molding with a flow mold.

[0005] Currently, active research is being conducted on manufacturing methods that enable the processed suture to have a multidirectional, three-dimensional (3D) shape rather than a unidirectional, flat (2D) shape.

[0006] In relation to this, referring to FIG. 1, a conventional manufacturing method applies a suture to a flow mold to form microprotrusions in a range higher than the glass transition temperature (Tg) and lower than the melting point (Tm), and then additionally hardens the suture with the microprotrusions formed in a state of tension and rotation in a range higher than the glass transition temperature (Tg) and lower than the melting point (Tm) so that it can have a three-dimensional shape.

[0007] However, this conventional manufacturing method requires an additional curing process of 3 to 24 hours, which increases manufacturing time and reduces productivity.

[0008] The present invention is intended to solve the problems of the prior art described above, and an object of the present invention is to provide a method for manufacturing a medical suture without an additional hardening operation and a medical suture manufactured thereby.

[0009] One aspect of the present invention is a medical suture including a suture body extending in one direction and having a twist formed therein and micro cogs formed on an outer surface of the suture body and arranged in a three-dimensional three-dimensional shape structure along the circumference of the suture body, wherein when a one-way length of a region in which a rotation angle at both ends is 180 degrees in the suture body is referred to as a twist interval n, and n of the suture body before and after the formation of the micro cogs is referred to as n1 and n2, respectively, n1 <n2인, 의료용 봉합사를 제공한다.

[0010] In one embodiment, the medical suture may be made of a bioabsorbable medical polymer material selected from the group consisting of polydioxanone, poly(L-Lactic) acid, polyglycolic acid, polycaprolactone, and copolymers thereof.

[0011] In one embodiment, the medical suture may be made of a bio-non-absorbable medical polymer material selected from the group consisting of polypropylene, nylon, and mixtures thereof.

[0012] In one embodiment, the microprotrusions may protrude in a direction inclined to the one direction.

[0013] In one embodiment, n2 may be greater than or equal to 0.6 cm and less than or equal to 45 cm.

[0014] Another aspect of the present invention provides a method for manufacturing a medical suture, characterized by including a step of applying a rotational force to a suture body extending in one direction to form a twist, and a step of applying the twisted suture body to a flow mold to form microprotrusions in a range higher than the glass transition temperature (Tg) and lower than the melting point (Tm).

[0015] In one embodiment, the method may further include removing the suture body having the micro-protrusions formed from the extrusion mold and partially untwisting the suture body.

[0016] In one embodiment, when the one-way length of the region in which the two-end rotation angle is 180 degrees in the suture body is referred to as the twist interval n, n of the suture body in the step where the twist is formed is referred to as n1, and n of the suture body in the step where the twist is partially released is referred to as n2, n1 <n2일 수 있다.

[0017] In one embodiment, n2 may be greater than or equal to 0.6 cm and less than or equal to 45 cm.

[0018] In one embodiment, in the step of forming the microprotrusions, compression molding can be performed with a force of 10 kg·f / cm2 or more and 200 kg·f / cm2 or less.

[0019] In one embodiment, in the step of forming the microprotrusions, compression molding can be performed with a force of 80 kg·f / cm2 or more and 180 kg·f / cm2 or less.

[0020] According to one aspect of the present invention, a medical suture according to one embodiment of the present invention can significantly improve productivity by drastically reducing the manufacturing time compared to a conventional manufacturing method that requires an additional curing operation of 3 to 24 hours or more.

[0021] In addition, the medical suture according to one embodiment of the present invention has the advantage of maintaining the tensile strength almost the same while significantly increasing the fixing force compared to a flat medical suture that is not twisted, and of maximally maintaining the inherent physical properties of the raw material.

[0022] 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 detailed description of the present invention or the composition of the invention described in the claims.

[0023] Figure 1 is a step diagram showing a conventional method for manufacturing a medical suture.

[0024] FIG. 2 is a drawing schematically showing a medical suture according to one embodiment of the present invention.

[0025] Figure 3 is an exemplary drawing showing a portion of a medical suture in a flat shape before being twisted.

[0026] FIG. 4 is an exemplary drawing showing a part of a three-dimensional medical suture according to one embodiment of the present invention.

[0027] Figure 5 is a step diagram showing a method for manufacturing a medical suture according to one embodiment of the present invention.

[0028] Figure 6 is a graph showing the results of comparing the tensile strength of a medical suture according to one embodiment of the present invention and the medical sutures of Comparative Examples 1 to 4.

[0029] Figure 7 is a graph showing the results of comparing the Young's modulus of medical sutures of Example 1 and Comparative Example 6.

[0030] Figure 8 is a schematic diagram for explaining the maximum holding force and the total holding force.

[0031] Figure 9 is a graph showing the results of a holding force test according to the final twist interval.

[0032] Hereinafter, the present invention will be described with reference to the attached drawings. However, the present invention can be implemented in various different forms and is therefore not limited to the embodiments described herein. In the drawings, irrelevant parts have been omitted for clarity of description, and similar parts have been designated with similar reference numerals throughout the specification.

[0033] Throughout the specification, when a part is said to be "connected" to another part, this includes not only "directly connected" but also "indirectly connected" with other elements intervening. Furthermore, when a part is said to "include" a component, this does not exclude other components, but rather implies that the other components may be included, unless otherwise specifically stated.

[0034] Terms containing ordinal numbers, such as "first" or "second," used herein may be used to describe various components or steps, but such components or steps are not limited by the ordinal numbers. Terms containing ordinal numbers should be interpreted only to distinguish one component or step from other components or steps.

[0035] When a range of numerical values ​​is described herein, unless a specific range is otherwise specified, the values ​​have the precision of the provided significant figures according to standard rules in chemistry for significant figures. For example, the number 10 includes a range of 5.0 to 14.9, and the number 10.0 includes a range of 9.50 to 10.49. Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings.

[0036] Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings.

[0037] The medical suture of the present invention is not only used for connecting or suturing various damaged areas of animal tissues such as skin, muscles, tendons, internal organs, bone tissue, nerves, blood vessels, etc., and incision areas resulting from surgical operations, but can also be used for cosmetic purposes such as tissue lifting operations such as facial lifting.

[0038] The medical suture of the present invention can be manufactured from a single-filament polymer. Specifically, for example, the medical suture can be manufactured from a bioabsorbable medical polymer comprising one or more of polydioxanone, monocryl, polycarprolactone, poly(glycolic acid), poly(lactic acid), poly(lactic-co-glycolic acid), poly(lactide-co-caprolactone), and polyhydroxyalkanoates.

[0039] 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.

[0040] The medical suture of the present invention is not limited to a specific material, and of course, all polymers can be applied.

[0041] Figure 2 is a schematic drawing of a medical suture according to one embodiment of the present invention.

[0042] A medical suture (10) according to one embodiment of the present invention includes a suture body (11) extending in one direction and microprotrusions (12).

[0043] The suture body (11) can be formed into a linear structure including elasticity, and the microprotrusions (12) can be formed on the outer surface of the suture body (11).

[0044] The micro-protrusions (12) are protrusions formed around the suture body (11), and may be formed in an inclined direction in one direction in which the suture body (11) extends. The micro-protrusions (12) may be implemented as barbs, etc., but are not necessarily limited thereto. Here, barbs refer to the shape of hooks in the shape of a hook, such as a fishing hook.

[0045] The suture body (11) can be formed into a twisted structure. Accordingly, the microprotrusions (12) can be arranged in a spiral shape along the circumference of the suture body (11) in a three-dimensional, three-dimensional shape structure.

[0046] FIG. 3 is an exemplary drawing showing a portion of a medical suture in a flat shape before being twisted, and FIG. 4 is an exemplary drawing showing a portion of a medical suture in a three-dimensional shape according to one embodiment of the present invention.

[0047] As shown in Fig. 3, assuming that a medical suture in a flat shape includes a suture body (B) and microprotrusions (C1, C2, C3, C4) formed only on one side of the suture body (B), when a predetermined rotational force is applied to the medical suture in such a flat shape, a medical suture in a three-dimensional shape as shown in Fig. 4 can be manufactured.

[0048] In detail, referring to FIG. 4, the microprotrusions (C1, C2, C3, C4) can be arranged in a three-dimensional stereoscopic shape structure along the circumference of the suture body (B) by a rotational force. As shown in FIG. 4, when the microprotrusions (C1, C3) or the microprotrusions (C2, C4) are positioned on opposite sides with respect to the central axis of the suture body (B), a spiral region (R) having a rotation angle of 180 degrees at both ends is formed between the microprotrusions (C1, C3) or the microprotrusions (C2, C4), and the spiral region (R) can be arranged repeatedly along one direction of the body (B).

[0049] In this specification, the one-way length of the region (R) where the two-end rotation angle forms 180 degrees is defined as the twist interval n.

[0050] In one embodiment, the twisted spacing n of the medical suture according to one embodiment of the present invention can be formed to be 0.6 cm or more.

[0051] In one embodiment, when the twist intervals before and after the formation of the microprotrusion are n1 and n2, respectively, n1 <n2일 수 있다. 상세하게는, 본 발명에서는 봉합사 몸체가 꼬임이 인가된 채 유출금형에 장착되므로, n1 은 0을 초과하여 형성된다. 아울러, 미세돌기 형성과정에서 봉합사 몸체의 경화된 일부 영역은 꼬여진 상태를 유지하지만, 경화가 되지 않은 영역은 꼬임이 자연스럽게 풀리면서 n2가 n1보다 커지게 된다.

[0052] Preferably, n1 can be formed to be 0.3 cm or more, and n2 can be formed to be 0.6 cm or more.

[0053] More preferably, n1 may be formed to be 0.3 cm or more and 22.5 cm or less, and n2 may be formed to be 0.6 cm or more and 45 cm or less.

[0054] Figure 5 is a step diagram showing a method for manufacturing a medical suture according to one embodiment of the present invention.

[0055] Hereinafter, a method for manufacturing a medical suture according to one embodiment of the present invention will be described with reference to FIG. 5.

[0056] Referring to FIG. 5, a method for manufacturing a medical suture according to one embodiment of the present invention includes a step of rotating a suture body (S100), a step of applying a twisted suture to a flow mold to form microprotrusions in a range higher than a glass transition temperature (Tg) and lower than a melting point (Tm) (S200), and a step of partially untwisting the suture body (S300).

[0057] In detail, in the step of rotating the suture body (S100), a predetermined rotational force is applied to the suture body extending in one direction so that a twist can be formed in the suture body.

[0058] In one embodiment, in the step of rotating the suture body (S100), a rotational force may be applied to the suture body so that the twisted interval n1 is approximately 0.3 cm or more. As described below, when the twisted interval n1 is less than approximately 0.3 cm, a medical suture having a final twisted interval n2 of approximately 0.6 cm or less can be manufactured.

[0059] In the step of forming microprotrusions (S200), the temperature applied is a specific temperature within the temperature condition of the melting point or lower and the glass transition temperature or higher of the suture raw material, and preferably, it is 15°C below the melting point (Tm-15°C) to 30°C below the melting point (Tm-30°C).

[0060] The pressure applied to the extrusion mold may be in the range of 10 to 200 kgf / cm2, preferably in the range of 80 to 180 kgf / cm2. If the pressure is less than the above range, the burr may not be removed by the extrusion mold, making it difficult to process the extrusion mold into a medical suture. If the pressure exceeds the above range, the durability of the extrusion mold may be weakened.

[0061] In the step of forming microprotrusions (S200), the suture body is also heated at a specific temperature within a temperature condition of lower than the melting point of the suture raw material and higher than the glass transition temperature, so a part of the suture body is hardened in a twisted state, but the rest of the suture body is not hardened because the heating-compression time is short.

[0062] In the partially untwisted stage (S300), the suture body with micro-protrusions formed is removed from the extrusion mold. Then, some areas that were hardened in stage S200 remain twisted, while areas that were not hardened naturally untwist, causing n2 to become greater than n1. Accordingly, the micro-protrusions (12) are arranged in a spiral shape around the circumference of the suture body (11) in a three-dimensional, three-dimensional structure.

[0063] Thus, according to the method for manufacturing a medical suture according to an embodiment of the present invention, in the step of forming microprotrusions (S200), the rotated suture is applied to the extrusion mold to form microprotrusions in a range higher than the glass transition temperature (Tg) and lower than the melting point (Tm), so that an additional curing process for maintaining twisting as in the prior art can be omitted. That is, the method for manufacturing a medical suture according to an embodiment of the present invention can significantly improve productivity by drastically reducing the manufacturing time compared to the prior art manufacturing method that requires an additional curing process of 3 to 24 hours.

[0064] Hereinafter, the embodiments of this specification will be described in more detail. However, the experimental results below represent only representative experimental results among the above embodiments, and the scope and content of this specification cannot be interpreted as being reduced or limited by the embodiments, etc. The effects of each of the various implementation examples of this specification that are not explicitly presented below will be specifically described in the relevant sections.

[0065]

[0066] Examples 1 to 10

[0067] A suture body made of polydioxanone was used, and medical sutures of Examples 1 to 10 were manufactured through a step of rotating the suture body according to an embodiment of the present invention, a step of applying the rotated suture to a flow mold to form microprotrusions in a range higher than the glass transition temperature (Tg) and lower than the melting point (Tm), and a step of partially untwisting the suture body. The twist interval n1 before forming the microprotrusions and the final twist interval n2 formed when the twist is partially untwisted after forming the microprotrusions are as shown in Table 1 below.

[0068]

[0069] Twist spacing before formation of micro-protrusions n1 (cm) Final twist spacing n2 (cm) Example 10.30.6 Example 20.3750.75 Example 30.450.9 Example 40.551.1 Example 50.651.3 Example 60.751.5 Example 71.53 Example 8510 Example 912.525 Example 1022.545

[0070] Comparative Example 1

[0071] A suture body of the same material as the example was used, and the suture body was applied to a flow mold to form microprotrusions in a range higher than the glass transition temperature (Tg) and lower than the melting point (Tm), thereby manufacturing a flat medical suture.

[0072]

[0073] Comparative Examples 2 to 5

[0074] Except for the twist spacing, the same method as in the examples was used. The twist spacing n1 before the formation of the microprotrusions and the final twist spacing n2 formed after the twisting is partially released after the formation of the microprotrusions are as shown in Table 2 below.

[0075]

[0076] Comparative Example 6

[0077] A suture body of the same material as the example was used, and the suture body was applied to a flow mold to form microprotrusions in a range higher than the glass transition temperature (Tg) and lower than the melting point (Tm), and the suture body with the microprotrusions formed was stretched and rotated in a vacuum state at a range higher than the glass transition temperature (Tg) and lower than the melting point (Tm) to manufacture a medical suture through an additional hardening step for 24 hours. The final twist spacing n2 is as shown in Table 2 below.

[0078]

[0079] Twisted spacing before formation of micro-protrusions n1 (cm) Final twisted spacing n2 (cm) Comparative example 1--Comparative example 20.1250.25 Comparative example 30.1750.35 Comparative example 40.2250.45 Comparative example 54590 Comparative example 6-0.6

[0080] Experimental Example 1: Measurement of the physical properties of medical sutures

[0081] Tensile strength is measured according to USP 43-NF38 of the U.S. Food and Drug Administration. <881> Tensile Strength was measured. Specifically, the medical sutures of the comparative examples and examples were fixed to the upper and lower parts of the clamps. The gauge distance between the clamps was set to 40 mm, and the clamp operating speed was set to 80 mm / min. The tensile strength was measured at the point where the medical suture broke, and the measurement was repeated 10 times, and the results are shown in Fig. 6. In addition, the Young's modulus of the medical sutures of Example 1 and Comparative Example 6 was measured, and the results are shown in Fig. 7.

[0082] Figure 6 is a graph showing the results of comparing the tensile strength of a medical suture according to one embodiment of the present invention and the medical sutures of Comparative Examples 1 to 4.

[0083] Referring to FIG. 6, it was confirmed that the medical sutures of Examples 1 to 6, in which the twist interval n2 was 0.6 cm or more, maintained almost the same tensile strength as the medical suture of Comparative Example 1, which is a flat medical suture that was not twisted. In contrast, it was confirmed that the medical sutures of Comparative Examples 2 to 4, in which the twist interval n2 was less than 0.6 cm, showed a sharp decrease in tensile strength as compared to the medical suture of Example 1 or Comparative Example 1.

[0084] Figure 7 is a graph showing the results of comparing the Young's modulus of medical sutures of Example 1 and Comparative Example 6.

[0085] Referring to Fig. 7, it was confirmed that the Young's modulus of the medical suture of Example 1 was reduced compared to the medical suture of Comparative Example 6. Since most human tissues have soft rigidity, the lower the Young's modulus of a medical suture, the more friendly it is to the human body.

[0086] In this regard, conventional manufacturing methods involve securing medical sutures to a separate jig in an additional curing step to apply tensile and rotational forces, resulting in stiffer properties (i.e., increased Young's modulus) than the raw material properties. In contrast, the present invention omits the aforementioned curing step, thereby maximizing the preservation of the raw material's inherent properties.

[0087]

[0088] Experimental Example 2: Measurement of the fixation strength of medical sutures

[0089] The fixation strength was measured using the fixation strength test medium described in the Korea Food and Drug Administration's Facial Tissue Fixation Thread Performance Evaluation Guidelines (MFDS).

[0090] In detail, the fixation test medium is composed of a three-layer structure of upper silicone, middle layer composed of gauze, and lower layer silicone. The medical suture of the comparative example or the example was inserted in parallel to the middle layer (gauze) of the fixation test medium by about 10 cm, and the fixation test medium and the end of the medical thread inserted between the medical sutures were fixed to the upper and lower ends of the clamp, respectively. Thereafter, the clamp was driven at a predetermined speed to pull the medical suture out of the fixation test medium, and the force for displacement of the medical thread was measured.

[0091] Figure 8 is a schematic diagram of a graph measured during a fixation force test.

[0092] Referring to Fig. 8, in the present invention, the measured maximum force (peak) was measured as the maximum fixing force, and the area of ​​the graph was measured as the total fixing force, and the results are shown in Fig. 9 and Table 3 below.

[0093]

[0094] Final twisted distance n2 (cm) Maximum holding force (N) Total holding force (N*m) Comparative example 20.25 23.52 ±3.0 31.00 ±0.17 Example 20.75 26.28 ±1.7 31.09 ±0.06 Example 61.5 21.89 ±1.7 30.82 ±0.09 Example 73 21.24 ±3.7 10.71 ±0.03 Example 810 21.88 ±4.2 90.71 ±0.08 Example 925 21.24 ±3.3 90.73 ±0.09 Example 104 5 20.79 ±4.3 60.77 ±0.07 Comparative example 59 0 21.51 ±3.0 70.63 ±0.17 Comparative example 1-18.52 ±4.860.68 ±0.20

[0095] Referring to Fig. 9 and Table 3, it was confirmed that as rotation was applied to the medical thread, the maximum fixing force and the overall fixing force increased, while the deviation generally decreased. In particular, when comparing Example 10 and Comparative Example 5, it can be confirmed that the overall fixing force significantly increased based on a final twist interval of 45 cm.

[0096] That is, the medical sutures of Examples 1 to 10 having a final twist interval of 0.6 cm to 45 cm can significantly improve productivity by drastically reducing the manufacturing time compared to the conventional manufacturing method that requires an additional curing process of 3 to 24 hours or more. In addition, the medical sutures of Examples 1 to 10 having a final twist interval of 0.6 cm to 45 cm have the advantage of significantly increasing the fixing force while maintaining almost the same tensile strength and maximally maintaining the inherent physical properties of the raw material compared to a flat medical suture that is not twisted.

[0097] The foregoing description of the present invention is for illustrative purposes only, and those skilled in the art will readily appreciate that the present invention can be readily modified into other specific forms without altering the technical spirit or essential characteristics 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 entity may be implemented in a distributed manner, and similarly, components described as distributed may be implemented in a combined manner.

[0098] The scope of the present invention is indicated by the claims set forth below, and all changes or modifications derived from the meaning and scope of the claims and their equivalent concepts should be interpreted as being included in the scope of the present invention.

[0099]

[0100] [Explanation of symbols]

[0101] 10 Medical Sutures

[0102] 11 Suture body

[0103] 12 microprotrusions

Claims

1. A medical suture comprising a suture body that extends in one direction and has a twist formed therein, and micro cogs formed on the outer surface of the suture body and arranged in a three-dimensional stereoscopic structure along the circumference of the suture body, When the one-way length of the region where the two ends of the suture body have a rotation angle of 180 degrees is called the twist interval n, and n of the suture body before and after the formation of the microprotrusion is called n1 and n2, respectively, n1 <n2인 것을 특징으로 하는, 의료용 봉합사.

2. In paragraph 1, The above medical sutures are, A medical suture, characterized in that it is made of a bioabsorbable medical polymer material selected from the group consisting of polydioxanone, poly(L-Lactic) acid, polyglycolic acid, polycaprolactone, and copolymers thereof.

3. In paragraph 1, The above medical sutures are, A medical suture, characterized in that it is made of a bio-non-absorbable medical polymer material selected from polypropylene, nylon, and mixtures thereof.

4. In paragraph 1, The above micro-protrusions are, A medical suture characterized by protruding in an inclined direction in the above one direction.

5. In paragraph 1, n2 is a medical suture characterized by a thickness of 0.6 cm to 45 cm.

6. A step in which a rotational force is applied to a suture body extending in one direction to form a twist; and A method for manufacturing a medical suture, characterized in that it includes a step of applying a twisted suture body to a flow mold and forming microprotrusions in a range higher than a glass transition temperature (Tg) and lower than a melting point (Tm).

7. In paragraph 6, A method for manufacturing a medical suture, characterized in that it further includes a step of removing a suture body having micro-protrusions formed thereon from a discharge mold and partially releasing the twist of the suture body.

8. In paragraph 7, The one-way length of the region in the above suture body where the two ends have a rotation angle of 180 degrees is called the twist interval n. The n of the suture body at the stage where the above twist is formed is called n1, When n of the suture body at the stage where the above twist is partially released is n2, n1 <n2인 것을 특징으로 하는, 의료용 봉합사의 제조방법.

9. In paragraph 8, n2 is a medical suture characterized by a thickness of 0.6 cm to 45 cm.

10. In paragraph 6, At the stage where the above microprotrusions are formed, A method for manufacturing a medical suture, characterized by performing compression molding with a force of 10 kg·f / cm2 or more and 200 kg·f / cm2 or less.

11. In paragraph 9, At the stage where the above microprotrusions are formed, A method for manufacturing a medical suture, characterized by performing compression molding with a force of 80 kg·f / cm2 or more and 180 kg·f / cm2 or less.

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