JP2023098873A - Method of producing cyclic structure for medical use, core material for use in method of producing cyclic structure for medical use, and cyclic structure for medical use - Google Patents

Abstract

To provide: a method of producing a cyclic structure for medical use that is used as a part of a blood vessel, an organ, etc., and that has biocompatibility, flexibility, resistance to leakage, etc.; a core material that is used in the method of producing the cyclic structure for medical use; and the cyclic structure for medical use.SOLUTION: A method of producing a cyclic structure 1 for medical use according to the present invention includes: a first step of forming a tubular first layer 10 by tightly wrapping silk fibroin fibers 40 so that no gap is made from the start to the end of the core material; a second step of forming an adhesive layer 20 on the outer surface of the first layer; third and fourth steps of forming a coating layer 30 by coarsely wrapping the silk fibroin fibers around the silk fibroin fibers so that gaps are made in an axial direction before the adhesive in the adhesive layer cures; and a fifth step of repeating the third and fourth steps until the silk fibroin fibers reach a predetermined thickness. By adjusting the ratio of hardened silk fibroin fibers 41 to non-hardened silk fibroin fibers 42 in the entire cyclic structure, the difficulty/ease of deformation of the cyclic structure can be adjusted.SELECTED DRAWING: Figure 1

Description

TECHNICAL FIELD The present invention relates to a method for producing a medical annular structure used as a part of a blood vessel, an organ, etc., a core material used in the method for producing a medical annular structure, and a medical annular structure.

Circular structures for medical use that are used as part of blood vessels, organs, etc. are known, and a typical example thereof is an artificial blood vessel.
Artificial blood vessels are required to have biocompatibility, flexibility, stretchability, durability, ease of suturing, resistance to fraying at the ends, resistance to blood leakage, etc., and these requirements can be met. Silk thread is known as a material.
For example, Patent Document 1 discloses a technique of smoothing the outer wall surface of a tubular structure formed by circularly winding silk fibroin fibers obtained by scouring raw silk by a method selected from knitting, weaving, weaving, and entangling. .

Japanese Patent Application Laid-Open No. 2009-279214

However, in the method of knitting or weaving silk fibroin fibers as in Patent Document 1, gaps are generated in the stitches during expansion and contraction, and blood tends to leak from the gaps. However, there is a problem that the thickness increases. Such a problem may arise not only when a circular structure made of silk thread is used as a blood vessel, but also when it is used as a part of an organ or the like.

In consideration of such problems, the present invention provides a method for producing a medical circular structure that is used as a part of a blood vessel, organ, or the like, and that has biocompatibility, flexibility, resistance to leakage, and the like. The object of the present invention is to provide a core material and a medical annular structure used in the annular structure manufacturing method of No.

In the manufacturing method of the annular structure for medical use of the present invention, silk fibroin fibers are densely wound from the starting point to the end point of the core material so as not to create a gap in the axial direction of the core material, thereby forming a cylindrical first layer. a first step of forming; a second step of forming an adhesive layer on the outer peripheral surface of said first layer; a third step of forming a coating layer by winding the silk fibroin fibers loosely around the first layer such that a A fourth step of forming a coating layer by roughly winding the silk fibroin fibers around the first layer so as to create a gap in the axial direction, and a third step until the silk fibroin fibers reach a predetermined thickness. and a fifth step of repeating the fourth step.
Moreover, it is characterized by comprising a sixth step of forming a coating layer on the surface of the outermost coating layer after the fifth step.
Also, in the first step, the silk fibroin fibers are brought into close contact with each other by pressing the silk fibroin fibers toward the starting point side in the axial direction.
Also, in the fifth step, a second adhesive layer is formed on the outer peripheral surface of the silk fibroin fiber.
Moreover, it is characterized by using only one silk fibroin fiber.
Further, after the fifth step, the core material is pulled out before the adhesive of the adhesive layer is cured.
Further, after the sixth step, the core material is pulled out before the adhesive of the adhesive layer is cured.

The core material of the present invention is the core material used in the above method for manufacturing an annular structure for medical use, and comprises a round bar and a plurality of cover members each having an arcuate cross-section covering the circumferential surface of the round bar. A slit extending in the longitudinal direction is provided between the adjacent cover members in a state in which the circumferential surface of the round bar is covered with the plurality of cover members.
The core material of the present invention is a core material used in the above-described method for manufacturing a medical annular structure, comprising a round bar, a first cylindrical member covering a circumferential surface of the round bar, and a circle of the first cylindrical member. a second cylindrical member covering a circumferential surface; and a third cylindrical member covering a circumferential surface of the second cylindrical member, wherein the first cylindrical member, the second cylindrical member and the third cylindrical member are longitudinal It is characterized by having a slit extending in a direction.
The annular structure for medical use of the present invention comprises a tubular first layer in which silk fibroin fibers are tightly wound so as not to form a gap in the axial direction from the start point to the end point, and on the outer peripheral surface of the first layer An adhesive layer to be formed and a plurality of coating layers formed by roughly winding the silk fibroin fibers around the first layer so as to create gaps in the axial direction, and constituting the coating layers. A part of the silk fibroin fibers is cured together with the adhesive layer, and the rest of the silk fibroin fibers is not cured together with the adhesive layer.
Moreover, it is characterized by comprising a coating layer formed on the surface of the outermost coating layer.

After forming the first layer by winding the silk fibroin fibers tightly so as not to create gaps, the silk fibroin fibers are loosely wound around the first layer before the adhesive in the adhesive layer hardens. In the coating layer close to the first layer, most of the silk fibroin fibers are hardened together with the adhesive layer, and only a small part is left unhardened together with the adhesive layer. As the coat layer becomes farther from the first layer, the proportion of silk fibroin fibers that harden together with the adhesive layer (hardened silk fibroin fibers) decreases, and conversely, silk fibroin fibers that do not harden together with the adhesive layer ( The proportion of uncured silk fibroin fibers) increases. Therefore, the ratio of hardened silk fibroin fibers and non-hardened silk fibroin fibers in the entire annular structure is adjusted, that is, the winding number and pitch of the silk fibroin fibers in each coating layer is adjusted, and the adhesive constituting the adhesive layer is used. By adjusting the amount of or adjusting the number of coating layers, the difficulty/easiness of deformation of the annular structure can be adjusted.

Since the silk fibroin fiber is used as the main material, it is possible to produce a circular structure for medical use with high biocompatibility.
Since the first layer is formed by tightly winding the silk fibroin fibers in the axial direction without gaps, the inner peripheral surface is a smooth surface with little unevenness. Therefore, thrombus or the like can be made difficult to occur.
By forming an adhesive layer on the outer peripheral surface of the densely wound first layer, it is difficult to stretch in the axial direction even when an external force is applied in the axial direction, and blood and body fluids passing through the hollow portion are less likely to leak to the outside.
By providing a coating layer on the surface of the outermost coating layer, it is possible to suppress misalignment and fluffing of the silk fibroin fibers constituting the outermost coating layer, smooth the surface of the annular structure, and smooth the ends of the silk fibroin fibers. The part can be fixed to the surface of the covering layer. Furthermore, fraying of the silk fibroin fibers at the ends (starting point and terminal point) of the annular structure can also be prevented.
By forming the second adhesive layer, the proportion of hardened silk fibroin fibers can be increased to make it difficult to deform the annular structure, and to make it difficult for blood and body fluids passing through the hollow portion to leak out to the outside. can be done.
By using a core material having a round bar and a plurality of cover members, the cover member can be taken out by using the hollow part formed after the round bar is pulled out, so that the manufacturing efficiency of the annular structure for medical use is improved. be able to.

Front view (a), cross-sectional view along A-A line (b), cross-sectional view along B-B line (c), and partially enlarged cross-sectional view (d) of a medical annular structure Front view (a) of the core material, cross-sectional view (b) in a direction orthogonal to the axial direction, front view (c) and cross-sectional view (d) showing the state in which the first layer is formed by winding silk fibroin fibers around the core material. ) Front view (a) showing a state in which a gap is generated in the axial direction and front view (b) showing a corrected state A cross-sectional view (a) and a partially enlarged cross-sectional view (b) showing a state in which an adhesive layer is formed. Front view (a), cross-sectional view (b), and partially enlarged cross-sectional view (c) showing a state in which a coating layer is formed. Front view (a), cross-sectional view (b), and partially enlarged cross-sectional view (c) showing a state in which a coating layer is formed. Partially enlarged cross-sectional views (a) to (c) showing the state in which the coating layers are stacked Partially enlarged cross-sectional view showing a state in which a coating layer is formed Front view (a) and partial enlarged cross-sectional view (b) showing a state in which the annular structure is deformed by receiving an external force. Perspective view (a) of the core material, cross-sectional view (b), and cross-sectional view (c) showing a modification of the core material Sectional view (a) before removing the round bar, Sectional view (b) showing the state after removing the round bar, and Sectional view (c) showing the state after removing the cover member Perspective views (a) to (d) showing the structure of the core material of the second embodiment. Perspective views (a) to (d) showing a method for manufacturing an annular structure. Front view of manufactured annular structure

The medical annular structure of the present invention and its manufacturing method will be described. In addition, in the following description, the “cyclic structure for medical use” may be simply referred to as “cyclic structure”.
As shown in FIG. 1, a medical annular structure 1 comprises a first layer 10, an adhesive layer 20 and a covering layer 30. As shown in FIG.
The first layer 10 has a cylindrical shape with a hollow portion, and as shown in FIG. It consists of winding. FIG. 1(d) is an enlarged cross-sectional view of the area framed by the square in FIG. 1(c), and since the silk fibroin fibers 40 constituting the first layer 10 are tightly wound, the length of the silk fibroin fibers 40 increases along the longitudinal direction. A longitudinal section appears.
Fibroin is "a kind of white matter of hard silkworms and the main component of silk fibers and spider silk" (Kojien). In the present invention, the term "silk fibroin fiber" refers to fibroin obtained by scouring raw silk taken from silkworm cocoons. The scouring removes the sericin from the raw silk. In the present invention, "winding silk fibroin fibers" refers to winding silk fibroin fibers twisted into threads (ply threads).

A well-known method may be used for scouring, for example, heated Marcel soap, sodium carbonate mixed aqueous solution, cocoon layer, cocoon thread, raw silk, etc. are placed in a container, and after thread manipulation, the mixture is boiled while being stirred. After that, it is boiled in an aqueous sodium carbonate solution, washed in heated distilled water several times, and then dried to remove sericin.

An adhesive layer 20 is formed on the outer peripheral surface of the first layer 10 .
The type of adhesive must be one that does not generate substances harmful to the human body, such as formaldehyde, organic mercury compounds, trichlorethylene, and hydrogen chloride. Examples of adhesives include starch glue as a natural raw material. Synthetic adhesives include acrylic resin emulsion adhesives, urethane resin adhesives, ether-based cellulose, ethylene-vinyl acetate resin emulsion adhesives, epoxy resin adhesives, vinyl acetate resin emulsion adhesives, and aqueous polymer-isocyanate adhesives. adhesives, polyvinyl acetate resin solution-based adhesives, and polyvinyl alcohol-based adhesives. Vinyl acetate resin emulsion adhesives are preferable, and polyvinyl alcohol-based adhesives are more preferable because they are low in cost, have good water dispersibility, and are excellent in practical use.

When forming the adhesive layer 20, for example, an adhesive substance is dissolved in a solvent to form an adhesive liquid having fluidity, and this is made into fine particles through an injection nozzle device and applied to the outer peripheral surface of the first layer 10. A method of injecting is mentioned. Alternatively, the adhesive may be applied directly to the outer peripheral surface of the first layer 10 with a brush or the like.
By forming the adhesive layer 20, the silk fibroin fibers 40 of the first layer 10, which are tightly wound so as not to create gaps in the axial direction, are adhered and fixed to each other. can be maintained. This makes it difficult for blood and body fluids passing through the hollow portion to leak to the outside.

The coating layer 30 is formed by loosely winding the silk fibroin fibers 40 around the first layer 10 with a gap in the axial direction before the adhesive of the adhesive layer 20 hardens. The first layer 10 is formed by densely winding the silk fibroin fiber 40 from the starting point P1 to the terminal point P2 of the core material C as shown in FIG. By roughly winding the fiber 40 from the end point P2 to the start point P1, the first coating layer 30 is formed on the outer peripheral surface of the first layer 10, and furthermore, as shown in FIG. The next coating layer 30 is formed by winding loosely from the start point P1 to the end point P2. In this way, the silk fibroin fiber 40 is repeatedly loosely wound from the start point P1 to the end point P2, and from the end point P2 to the start point P1, so that the desired annular structure 1 is formed as shown in FIGS. 1(c) and 1(d). A plurality of coating layers 30 are formed around the first layer 10 to a thickness.

A coating layer 50 is provided on the surface of the outermost coating layer 30 . The coating layer 50 suppresses misalignment and fluffing of the silk fibroin fibers 40 that form the outermost coating layer 30, making the surface of the annular structure 1 smooth, and the ends of the silk fibroin fibers 40 are smoothed onto the surface of the coating layer 30. can be adhered and fixed to Furthermore, since fraying of the silk fibroin fibers 40 at the ends (starting point and terminal point) of the annular structure 1 can be prevented, for example, the ends of the annular structure 1 and the ends of blood vessels can be strongly anastomosed. can.
The type of coating agent that constitutes the coating layer 50 must not generate substances that are harmful to the human body. Examples of coating agents include, but are not limited to, the same adhesives as described above.

By loosely wrapping the silk fibroin fibers 40 around the first layer 10 before the adhesive of the adhesive layer 20 hardens, silk fibroin fibers 40 are formed in the covering layer 30 close to the first layer 10 as shown in FIG. 1(d). Most of the fibroin fibers 40 are cured with the adhesive layer 20 and only a small portion are left uncured with the adhesive layer 20 . As the coating layer 30 becomes farther from the first layer 10, the ratio of the silk fibroin fibers 40 that harden together with the adhesive layer 20 decreases, and conversely, the ratio of the silk fibroin fibers 40 that hardens together with the adhesive layer 20 decreases. percentage is increasing. In this specification, the silk fibroin fibers 40 that are cured together with the adhesive layer 20 are referred to as "cured silk fibroin fibers 41", and the silk fibroin fibers 40 that are not cured together with the adhesive layer 20 are referred to as "uncured silk fibroin fibers 42". ”.

The hardened silk fibroin fibers 41 are deformed, that is, bent or twisted together with the first layer 10 when the annular structure 1 receives an external force. Therefore, the more hardened silk fibroin fibers 41 are, the more difficult it is to deform the annular structure 1 .
On the other hand, the non-hardened silk fibroin fibers 42 move in the gaps 60 when the annular structure 1 receives an external force, so that they do not deform integrally with the first layer 10 or deform to a lesser extent. Therefore, the more non-hardened silk fibroin fibers 42 are, the more easily the annular structure 1 can be deformed.
Looking at the proportions of the cured silk fibroin fibers 41 and the non-cured silk fibroin fibers 42 in the coating layer 30 as described above, the proportion of the cured silk fibroin fibers 41 is relatively high in the coating layer 30 near the first layer 10, The proportion of hardened silk fibroin fibers 41 becomes relatively low as the distance from the layer 10 increases. Therefore, by adjusting the ratio of the cured silk fibroin fibers 41 and the non-cured silk fibroin fibers 42 in the entire annular structure 1, that is, by adjusting the winding number and pitch of the silk fibroin fibers 40 in each coating layer 30, By adjusting the amount of adhesive that constitutes 20 or the number of coating layers 30, the difficulty/easiness of deformation of annular structure 1 can be adjusted.

A method for manufacturing the annular structure 1 for medical use will be described.
First, as shown in FIGS. 2(a) and 2(b), a core material C for winding silk fibroin fibers 40 is prepared. The core material C is a rod-shaped member with a circular cross section, and the material thereof is not particularly limited and may be plastic resin, metal, wood, paper, or the like. The core material C may be solid or hollow, but a hollow material is used in this embodiment. The length and diameter of the core material C may be determined based on the length and diameter of the annular structure 1 to be produced. A start point P1 and an end point P2 are determined on the surface of the core material C.
Next, as shown in FIGS. 2(c) and 2(d), the silk fibroin fibers 40 are tightly wound from the start point P1 to the end point P2 of the core material C so as not to create a gap in the axial direction of the core material C, thereby forming a cylinder. forming a shaped first layer 10 (first step). In order to facilitate understanding, the silk fibroin fibers 40 are shown thicker than they actually are in FIG. A machine may be used for the winding operation, or an operator may perform the operation manually.

In the first step, when winding the silk fibroin fiber 40, if a slight gap occurs in the axial direction as shown in FIG. The silk fibroin fiber 40 may be corrected by pressing it toward the starting point P1 in the axial direction. As a result, the silk fibroin fibers 40 can be wound while being brought into close contact with each other.
After forming the first layer 10, an adhesive layer 20 is formed on the outer peripheral surface of the first layer 10 as shown in FIGS. 4(a) and 4(b) (second step). The adhesive may be sprayed or applied in liquid form as described above. At this time, it is preferable that the adhesive stays on the outer peripheral surface of the first layer 10, that is, does not reach the inner peripheral surface of the first layer 10. FIG. If the adhesive reaches the inner peripheral surface of the first layer 10, the adhesive may be eluted and mixed with blood or body fluids. In order to fix the adhesive on the outer peripheral surface of the first layer 10, it is necessary to select an appropriate one in consideration of the viscosity and penetration of the adhesive.

Next, as shown in FIGS. 5(a) and 5(b), the silk fibroin fibers 40 are placed in the first layer so that a gap is formed in the axial direction from the end point P2 to the start point P1 before the adhesive of the adhesive layer 20 hardens. It is loosely wrapped around 10 to form a covering layer 30 (third step). For ease of understanding, the silk fibroin fibers 40 forming the coating layer 30 are shown in a darker color than the silk fibroin fibers 40 forming the first layer 10 in FIG. 5(a). One end of the silk fibroin fiber 40 (the end on the side of the starting point P1) can be prevented from fraying by winding the silk fibroin fiber 40 so as to press it from above. The pitch at which the silk fibroin fibers 40 forming the coating layer 30 are wound may be uniform as shown in FIG. 5(a), or may be random as shown in FIG. 1(a).
As shown in FIG. 5(c), almost all of the silk fibroin fibers 40 are in close contact with the adhesive layer 20 at this stage, and these silk fibroin fibers 40 become cured silk fibroin fibers 41 after the adhesive is cured. .

Furthermore, as shown in FIGS. 6(a) and 6(b), before the adhesive of the adhesive layer 20 hardens, the silk fibroin fibers 40 are arranged in the first layer so that there is a gap in the axial direction from the start point P1 to the end point P2. It is loosely wrapped around 10 to form a coating layer 30 (fourth step).
As shown in FIG. 6(c), almost all of the silk fibroin fibers 40 are in close contact with the adhesive layer 20 even at this stage, and these silk fibroin fibers 40 become cured silk fibroin fibers 41 after the adhesive is cured. . If the amount of adhesive in the adhesive layer 20 is small, some of the silk fibroin fibers 40 may not adhere to the adhesive layer 20 at this stage.
After that, the third step and the fourth step are repeated until the silk fibroin fiber 40 reaches a predetermined thickness (fifth step).

As shown in FIGS. 7(a) to 7(c), the third step and the fourth step are repeated to loosely wind the silk fibroin fiber 40, that is, as the distance from the first layer 10 increases, the hardened silk fibroin fiber 41 becomes thicker. The proportion becomes relatively low, and the proportion of uncured silk fibroin fibers 42 becomes relatively high.
Next, as shown in FIG. 8, a coating layer 50 is formed on the surface of the outermost coating layer 30 (sixth step). The other end of the silk fibroin fiber 40 is adhered and fixed by the coating layer 50 to prevent fraying.
Finally, the annular structure 1 is completed by extracting the core material C. The timing for extracting the core material C is preferably before the adhesive of the adhesive layer 20 hardens. Note that the coating layer 50 may be formed after the core material C is extracted.

As indicated by the arrows in FIG. 9(a), the annular structure 1 deforms when subjected to an external force. At this time, as shown in FIG. 9(b), the non-hardened silk fibroin fibers 42 move in the gap 60, so that the non-hardened silk fibroin fibers 42 increase the flexibility of the annular structure 1 when receiving an external force. It makes it easy to deform by pressing, and makes it difficult for the annular structure 1 to break or crack.

Incidentally, when manufacturing the annular structure 1 having a large thickness, the second adhesive layer 20 may be formed in the fifth step. In other words, the ratio of the cured silk fibroin fibers 41 may be increased by spraying or applying an adhesive to the coating layer 30 at the timing when the silk fibroin fibers 40 are roughly wound.
It is preferable to manufacture the circular structure 1 by winding one silk fibroin fiber 40 without cutting it, but if the silk fibroin fiber 40 is cut during the manufacturing process, the cut ends are tied together. or by twisting them together.

A first embodiment of the core material will be described.
As described above, the core material C may be a solid or hollow rod-shaped member having a circular cross section, but it may also be provided with a round rod 70 and a plurality of cover members 71 as shown in FIGS. 10(a) and 10(b). FIG. 10(c) shows a case where three cover members 71 are provided.
The round bar 70 may be solid or hollow. The cover member 71 has an arcuate cross-section that covers the circumferential surface of the round bar. When viewed in cross section, the radius of curvature of the circumferential surface (outer peripheral surface) of the round bar 70 and the radius of curvature of the inner peripheral surface of the cover member 71 match or substantially match.
When the circumferential surface of the round bar 70 is covered with a plurality of cover members 71, longitudinally extending slits 72 are formed between adjacent cover members 71. As shown in FIG.

As shown in FIG. 11(a), when manufacturing the annular structure, the silk fibroin fiber is wound around the outer peripheral surface of the cover member 71 to form the first layer 10, followed by the adhesive layer 20 and a plurality of coating layers. 30, forming a coating layer 50; When finally extracting the core material, the round bar 70 is first extracted as shown in FIG. 11(b). As a result of winding the silk fibroin fiber 40 many times, a large pressing force acts on the outer peripheral surface of the cover member 71, and part of the adhesive reaches the inner peripheral surface of the first layer 10. Since the adhesive adheres to the cover member 71 and hardens, it is difficult to pull out the round bar 70 and the cover member 71 at the same time, but the round bar 70 alone can be pulled out relatively easily.
Next, since the hollow portion 73 is formed after the round bar 70 is pulled out, the plurality of cover members 71 can be taken out sequentially using the hollow portion 73 as shown in FIG. 11(c).

A second embodiment of the core material will be described, but portions having the same configuration as in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.
As shown in FIG. 12(a), the present embodiment is characterized in that the core member C includes a round bar 70, a first cylindrical member 80, a second cylindrical member 81 and a third cylindrical member .
Each cylindrical member 80-82 is provided with a slit 83 extending longitudinally. The material of each of the cylindrical members 80 to 82 is not particularly limited, and may be plastic such as polypropylene, paper, wood, or the like. The radius of curvature of each of the cylindrical members 80-82 is substantially the same as the radius of curvature of the round bar .

First, the first cylindrical member 80 is attached to the round bar 70 as shown in FIG. 12(b). Specifically, the round bar 70 is inserted through the opening at one end of the first cylindrical member 80 while widening the slit 83 of the first cylindrical member 80 . As a result, the first cylindrical member 80 covers the circumferential surface of the round bar 70 .
Next, the round bar 70 and the first cylindrical member 80 are inserted through the opening at one end of the second cylindrical member 81 while widening the slit 83 of the second cylindrical member 81 as shown in FIG. 12(c). As a result, the second cylindrical member 81 covers the circumferential surface of the first cylindrical member 80. As shown in FIG.

Finally, as shown in FIG. 12(d), while widening the slit 83 of the third cylindrical member 82, the round bar 70, the first cylindrical member 80, and the second cylindrical member 80 are removed from the opening at one end of the third cylindrical member 82. Insert member 81 . Thereby, the third cylindrical member 82 covers the circumferential surface of the second cylindrical member 81, that is, the surface of the round bar 70 is covered with three layers of the first cylindrical member 80, the second cylindrical member 81 and the third cylindrical member 82. become.
Alternatively, the first cylindrical member 80, the second cylindrical member 81, and the third cylindrical member 82 may be stacked in advance, and the round bar 70 may be inserted last.

As shown in FIG. 13(a), when manufacturing the annular structure, the silk fibroin fiber 40 is wound around the outer peripheral surface of the third cylindrical member 82 to form the first layer 10, and then the adhesive layer 20, a plurality of A coating layer 30 and a coating layer 50 are formed. Then, before the adhesive layer 20 hardens, first, only the second cylindrical member 81 is removed from the round bar 70 as shown in FIG. 13(b). As described above, as a result of winding the silk fibroin fibers 40 many times, a large pressing force acts on the outer peripheral surface of the third cylindrical member 82, and part of the adhesive is inside the first layer 10. If it reaches the peripheral surface, the adhesive may adhere to the third cylindrical member 82 and harden, making it difficult to remove the annular structure 1 from the third cylindrical member 82 suddenly. However, it is easy to extract only the second cylindrical member 81 sandwiched between the first cylindrical member 80 and the third cylindrical member 82 . In particular, if the cylindrical members 80 to 82 are made of plastic such as polypropylene, the surface is smooth and the slidability is improved, so that only the second cylindrical member 81 can be easily pulled out.

Next, as shown in FIG. 13(c), the third cylindrical member 82 is extracted from the round bar 70 together with the annular structure 1. Then, as shown in FIG. Since the second cylindrical member 81 does not exist, a slight gap is generated between the first cylindrical member 80 and the third cylindrical member 82, so that the third cylindrical member 82 can be easily pulled out together with the annular structure 1. .
Finally, pressure is applied toward the center of the third cylindrical member 82 . Since the third cylindrical member 82 is provided with a slit 83, it can be deformed to reduce its diameter by applying pressure. As shown in FIG. 13(d), the annular structure 1 is obtained by extracting the third cylindrical member 82 whose diameter is reduced.

As shown in FIG. 14, a ring structure was produced using the method for producing a ring structure for medical use according to the present invention. The length is about 10 cm, the outer diameter is about 4 mm, the inner diameter is about 3 mm, and 84 denier yarn is used. It has flexibility, no leakage was confirmed when liquid was passed through the hollow part, and no breakage or cracking occurred when it was pulled in the longitudinal direction.

INDUSTRIAL APPLICABILITY The present invention relates to a method for manufacturing a circular structure for medical use, which is used as a part of a blood vessel, an organ, etc., and has biocompatibility, flexibility, resistance to leakage, etc., and a method for manufacturing a circular structure for medical use. It is a core material and a circular structure for medical use, and has industrial applicability.

C core material
P1 start point
P2 end point
1 Medical circular structure
10 first layer
20 adhesive layers
30 cover layer
40 silk fibroin fiber
41 Cured Silk Fibroin Fiber
42 Uncured silk fibroin fiber
50 coating layers
60 Gap
70 round bar
71 Cover member
72 slit
73 Hollow part
80 first cylindrical member
81 Second cylindrical member
82 third cylindrical member
83 slit

Claims (11)

a first step of forming a cylindrical first layer by densely winding silk fibroin fibers from the starting point to the end point of the core material so as not to create a gap in the axial direction of the core material;
a second step of forming an adhesive layer on the outer peripheral surface of the first layer;
Before the adhesive of the adhesive layer hardens, the silk fibroin fibers are loosely wound around the first layer so as to form a gap from the end point to the start point in the axial direction to form a coating layer. 3 steps and
Before the adhesive of the adhesive layer hardens, the silk fibroin fibers are loosely wound around the first layer so as to form a gap from the starting point to the end point in the axial direction to form a coating layer. 4 steps and
A method for manufacturing a circular structure for medical use, comprising a fifth step of repeating the third step and the fourth step until the silk fibroin fibers have a predetermined thickness.
2. The method for manufacturing an annular structure for medical use according to claim 1, further comprising, after the fifth step, a sixth step of forming a coating layer on the outermost coating layer.
3. The circular structure for medical use according to claim 1, wherein in the first step, the silk fibroin fibers are brought into close contact with each other by pressing the silk fibroin fibers toward the starting point side in the axial direction. manufacturing method.
2. The method for manufacturing a medical annular structure according to claim 1, wherein in said fifth step, a second adhesive layer is formed on the outer peripheral surface of said silk fibroin fiber.
2. The method for producing a circular structure for medical use according to claim 1, wherein only one silk fibroin fiber is used.
2. The method for manufacturing an annular structure for medical use according to claim 1, wherein after the fifth step, the core material is pulled out before the adhesive of the adhesive layer is cured.
3. The method for manufacturing an annular structure for medical use according to claim 2, wherein after the sixth step, the core material is pulled out before the adhesive of the adhesive layer is cured.
In the core material used in the method for producing a medical annular structure according to claim 1,
A round bar and a plurality of cover members each having an arcuate cross-section covering a circumferential surface of the round bar are provided. A core material comprising longitudinally extending slits between the members.
In the core material used in the method for producing a medical annular structure according to claim 1,
A round bar, a first cylindrical member covering the circumferential surface of the round bar, a second cylindrical member covering the circumferential surface of the first cylindrical member, and a third cylinder covering the circumferential surface of the second cylindrical member and
A core material, wherein the first cylindrical member, the second cylindrical member and the third cylindrical member have longitudinally extending slits.
a cylindrical first layer in which silk fibroin fibers are tightly wound so as not to create gaps in the axial direction from the starting point to the end point;
an adhesive layer formed on the outer peripheral surface of the first layer;
comprising a plurality of coating layers in which the silk fibroin fibers are loosely wound around the first layer so as to create gaps in the axial direction;
A part of the silk fibroin fibers constituting the coating layer is cured together with the adhesive layer, and the rest of the silk fibroin fibers is not cured together with the adhesive layer. ring structure.
11. The annular structure for medical use according to claim 10, further comprising a coating layer formed on the outermost coating layer.

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