KR101602402B1 - Stent - Google Patents

Abstract

The present invention relates to a stent, and more particularly, to a stent comprising: a stent body in the form of a tube having metal wires intersecting with each other to form a lattice or a mesh network, A first coating layer surrounding the surface of the stent body; And a second coating layer formed on a surface of the first coating layer, wherein the second coating layer is formed on the surface of the first coating layer so as to prevent a substance passing through the lesion site from adhering to the surface of the first coating layer, And may be formed of a polymer solution having a coefficient of friction.
According to the present invention, it is possible to prevent the substance passing through the lesion site from being deposited on the surface of the stent through the coating layer having a low frictional force and to prevent the coating layer of the stent from directly contacting the lesion site of the bile duct and blood vessel with the substance passing through the stent And the contact surface of the coating layer formed on the stent supports the bile duct and the inner wall of the blood vessel, thereby preventing the restenosis of the bile duct and the blood vessel caused by penetration of the new inner wall into the stent.

Description

Stent {STENT}

The present invention relates to a stent.

Various diseases can occur when the flow of blood or body fluids such as blood vessels and bile ducts is not smooth due to the occurrence of malignant or benign diseases.

In the case of blood vessels, blood circulation disorder and muscle pain may be induced. In case of severe symptoms, it may be necessary to cut the site. In the case of bile ducts, when the bile is narrowed or closed by tumor, Jaundice, itching, and sepsis may occur.

To treat these diseases, balloon catheters and other devices have been inserted into the blood vessels and bile ducts to expand the narrowed vessels and the inner wall of the bile ducts.

However, such balloon dilatation may cause restenosis due to narrowing or clogging of blood vessels and bile ducts after the procedure due to chronic shrinkage of the expanded blood vessels and bile ducts and neointimal hyperplasia.

In order to solve such a problem, in Korean Patent Laid-Open Publication No. 2012-0138974 (Announcement: 2012.12.27, hereinafter referred to as prior art), after the angioplasty, the blood vessel is inserted into the blood vessel to support the inner wall of the blood vessel, Stent to prevent vessel restenosis caused by chronic contraction of the stent.

However, in the prior art, since the stent supporting the blood vessel is composed only of a metal wire, substances such as blood, bile and protein pellets passing through the lesion can be deposited on the stent, and substances passing through the stent can be contacted In addition, there is a problem that the new inner lining can propagate through the gap of the wire, and restenosis may occur.

Disclosure of the Invention The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to prevent deposition of a substance passing through a lesion site, to protect a lesion site from a substance adhered to blood vessels and bile ducts, The present invention also provides a stent for preventing stenosis.

To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described herein, there is provided a stent comprising: a stent body in the form of a tube having metal wires crossing each other to form a lattice or mesh network; A first coating layer surrounding the surface of the stent body; And a second coating layer formed on a surface of the first coating layer, wherein the second coating layer is formed on the surface of the first coating layer so as to prevent a substance passing through the lesion site from adhering to the surface of the first coating layer, And may be formed of a polymer solution having a coefficient of friction.

The first coating layer may be formed of a composition of at least one of medical polyurethane, silicone urethane copolymer, silicone, polyamide, polyester and fluorine resin.

The second coating layer may be formed by spraying or immersing the polymer solution on the surface of the first coating layer.

The polymer solution may be a silicone polymer solution having the same structural formula but produced by a plurality of polymers having different number of chains and a crosslinking agent for bonding the plurality of polymers.

Here, the plurality of polymers may be a polysiloxane containing a vinyl group.

In addition, the crosslinking agent may be polymethylhydrogen siloxane.

As described above, the present invention has the following effects.

First, through the coating layer having a low frictional force, it is possible to prevent the deposition of the substance passing through the lesion site on the surface of the stent.

Second, the coating layer formed on the stent can prevent the material passing through the lesion area of the bile duct and the blood vessel from contacting the lesion area through the inside of the stent.

Third, since the contact surface of the coating layer formed on the stent supports the bile duct and the inner wall of the blood vessel, it is possible to prevent restenosis of the bile duct and blood vessel caused by penetration of the new inner wall into the stent.

1 is a perspective view illustrating a section of a stent and a stent according to an embodiment of the present invention.
2 is ASTM D1894-14 measuring instrument for measuring the friction value of a second coating layer of a stent according to an embodiment of the present invention.
FIG. 3 is a graph showing a result of measuring a friction value between a silicone coating forming a second coating layer of a stent and a conventional silicone coating according to an embodiment of the present invention.
4 is a flowchart illustrating a method of manufacturing a stent according to an embodiment of the present invention.

The preferred embodiments of the present invention will be described in more detail with reference to the accompanying drawings, in which the technical parts already known will be omitted or compressed for simplicity of explanation.

1 is a perspective view of a stent according to an embodiment of the present invention.

The stent 100 according to an embodiment of the present invention may include a stent body 110, a first coating layer 120, and a second coating layer 130.

The stent body 110 may have a plurality of metal wires 112 each having a corrugated shape along the longitudinal direction connected to various shapes such as a lattice shape or a mesh shape and a cylindrical shape having a hollow in the longitudinal direction.

The shape memory alloy wire 112 constituting the stent body 110 is made of a material such as nickel-titanium alloy, and the stent body 110 can be expanded or contracted in the circumferential direction at a specific temperature.

In addition, the stent body 110 inserted into the lesion of the biliary tract and the blood vessel can expand toward the inner wall of the bile duct and the blood vessel to support the inner wall.

The first coating layer 120 is formed to surround the stent body 110 to prevent direct contact between lesions of the bile duct and lesions of the blood vessel and lesions, When the inner wall is inflated to support the inner wall, the area contacted with the inner wall is widened so that it can be brought into close contact with the lesion site.

The composition of the first coating layer 120 may include, but not limited to, a medical solution of at least one of medical polyurethane, silicone urethane copolymer, silicone, polyamide, polyester and fluorine resin solution.

The second coating layer 130 may be formed by spraying or immersing a silicon polymer solution on the surface of the first coating layer 120.

The second coating layer 130 has a relatively low coefficient of friction as compared to the first coating layer 120 so that substances such as blood, bile, protein residue, etc., passing through the stent 100 provided in the lesion region, Can be prevented from being deposited.

In addition, the silicone solution of the second coating layer 130 may be generated through a crosslinking agent used for crosslinking with a plurality of polymers having the same structural formula but showing a difference in the number of chains constituting the polymer.

Preferably, the plurality of polymers have the same structural formula but two kinds of polysiloxanes containing vinyl groups, which show a difference in the number of chains constituting the polymer, may be used, and polymethylhydrogensiloxane may be used as the crosslinking agent.

On the other hand, the silicon solution constituting the second coating layer 130 of the stent 100 can be produced from two types of polysiloxane containing a vinyl group of the structural formula 1 and a polymethylhydrogen siloxane of the structural formula 2.

[ Structure 1 ]

(Where x is a natural number and y is a natural number including 0).

At this time, the two types of vinyl groups-containing polysiloxanes may be polysiloxanes having different values of x and y in the structural formula 1, respectively. Also, the polysiloxane containing two kinds of vinyl groups can be stirred at a mass ratio of 1: 1.

의 메틸기이다.
Here, Me is

Lt; / RTI >

[ Structure 2 ]

(Where a and b are natural numbers, respectively).

Here, the polymethylhydrogensiloxane of the structural formula 2 is used as a crosslinking agent for binding of the polymer mixture stirred at a 1: 1 mass ratio.

[ Structure 3 ]

(비닐기)와 구조식2의 H 가

(메틸렌)으로 치환되며 추가적인 이산화탄소, 물 등의 생성물 없이 결합되어진다.At this time,

(Vinyl group) and H of formula 2

(Methylene), and they are bonded without any additional products such as carbon dioxide and water.

The silicone solution thus formed is sprayed or immersed on the surface of the first coating layer 120 and is cured to form the second coating layer 130.

At this time, by adding a platinum organic compound to the silicon solution, the curing process of the silicon solution can be promoted.

FIG. 2 is an ASTM D1894-14 measuring instrument for measuring a friction value of a second coating layer of a stent according to an embodiment of the present invention, and FIG. 3 is a view for explaining a method of forming a second coating layer of a stent according to an embodiment of the present invention A silicon coating and a conventional silicon coating.

2, a silicon thin film for forming the second coating layer 130 and an existing silicon thin film were prepared in a measuring device of ASTM D1894-14 in a size of 50 x 150 mm, and 201.98 g of the friction material was transversely oriented at 12 inch / min The friction value was measured under the condition of moving at a speed of.

Here, when the silicon thin film or the conventional silicon thin film forming the second coating layer 130 of the present invention is placed under the friction material and the friction material is dragged at a constant speed (12 inch / min) By measuring the weight of the friction material with time, the same result as the graph of Fig. 3 was obtained.

3, the minimum frictional value, the maximum frictional value, and the average frictional coefficient of the section in which the friction material maintains a constant speed and the movement progressed, of the silicon thin film forming the second coating layer 130 of the present invention and the conventional silicon thin film , And the results shown in Table 1 were obtained.

[Table 1]

As shown in FIG. 3 and Table 1, the silicon polymer forming the second coating layer 130 of the present invention has a lower friction value in the entire section than the conventional silicon.

Thus, it can be seen that the stent 100 according to the present invention has an improved effect of preventing deposition from blood, bile, protein residue, etc., compared to a conventional silicone-coated stent.

4 is a flowchart illustrating a method of manufacturing a stent according to an embodiment of the present invention.

A step of preparing the stent body 110 so that the first coating layer 120 can be uniformly formed on the stent body 110 is performed.

Here, in order to remove foreign substances adhering to the surface of the stent body 110, the ultrasonic cleaner is washed with ethanol and distilled water mixed solvent for 1 hour and dried in a hot air drier at 50 to 70 ° C for 12 to 24 hours.

Thereafter, a first coating layer is formed on the surface of the stent body 110 by using a method of immersing the composition forming the first coating layer 120, an ultrasonic spraying method, an electrospinning method, etc. (S200)

Here, the solution for forming the first coating layer 120 was coated on the stent body 110, then placed in a drying oven at 35 ° C for primary drying for 30 minutes, placed in a 180 ° C drying oven, .

Thereafter, the second coating layer 130 is formed on the surface of the dried first coating layer 120 by immersing and spraying the silicon polymer solution (S300)

The second coating layer 130 is formed by curing the silicone solution on the surface of the first coating layer 120 by drying the ventilation at a room temperature for a minimum of 5 minutes and then performing secondary drying for 20 minutes under reduced pressure in a 150 ° C vacuum oven .

As a result, in the present invention, the lesion site is protected from the contact of the substance passing through the inside of the stent, and the coating layer is held in close contact with the inner wall of the lesion site, And prevents the material passing through the lesion site from depositing on the surface through a coating layer having a low frictional force.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. And the scope of the present invention should be understood as the following claims and their equivalents.

100: stent
110: stent body
120: first coating layer
130: Second coating layer

Claims (6)

A stent body in the form of a tube in which metal wires intersect each other to form a lattice or mesh-like net and a hollow inside;
A first coating layer surrounding the surface of the stent body; And
And a second coating layer formed on a surface of the first coating layer,
Wherein the second coating layer is formed of a polymer solution having a coefficient of friction lower than that of the first coating layer to prevent a substance passing through the lesion site from adhering to the surface of the first coating layer,
Wherein the polymer solution is a silicone polymer solution having the same structural formula but produced by a plurality of polymers having different number of chains and a crosslinking agent for bonding the plurality of polymers
Stent.
The method according to claim 1,
Wherein the first coating layer is composed of a composition of at least one of medical polyurethane, silicone urethane copolymer, silicone, polyamide, polyester and fluorine resin
Stent.
The method according to claim 1,
And the second coating layer is formed by spraying or immersing the polymer solution on the surface of the first coating layer
Stent.
delete The method according to claim 1,
Wherein the plurality of polymers is a polysiloxane containing a vinyl group
Stent.
The method according to claim 1,
Characterized in that the crosslinking agent is polymethylhydrogen siloxane
Stent.

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