WO2015167090A1

WO2015167090A1 - Stent

Info

Publication number: WO2015167090A1
Application number: PCT/KR2014/009965
Authority: WO
Inventors: 한종현; 김은진; 박헌국; 장봉석; 윤호; 김선종
Original assignee: 주식회사 엠아이텍
Priority date: 2014-04-29
Filing date: 2014-10-22
Publication date: 2015-11-05
Also published as: KR101602402B1; KR20150124647A

Abstract

The present invention relates to a stent comprising: a hollow tubular stent body in which metal wires cross each other to form a lattice or mesh form of net; a first coating layer formed to surround the surface of the stent body; and a second coating layer formed on the surface of the first coating layer, wherein the second coating layer may be formed of a polymer solution having a lower frictional coefficient than the first coating layer in order to prevent a substance passing through a site of lesion from being attached to the surface of the first coating layer. According to the present invention, thanks to the coating layer having a low frictional force, a substance passing through a site of lesion can be prevented from sticking to the surface of the stent, and the coating layer of the stent can prevent sites of lesion of a bile passage and a blood vessel from making a direct contact with a substance passing through the stent. In addition, the contact surface of the coating layer formed on the stent can support the inner walls of the bile passage and the blood vessel, thereby preventing restenosis of the bile passage and the blood vessel caused by neointima penetrating into the stent.

Description

Stent

The present invention relates to stents.

When the flow of blood or body fluids, such as blood vessels and biliary tracts, is not smooth due to the occurrence of malignant or benign diseases, various diseases may occur.

In the case of blood vessels, blood circulation disorders and muscle pain may be caused, and in severe cases, the site may need to be cut, and in the case of bile ducts, fever, when the excretion of bile is not narrowed or closed by the tumor, Symptoms such as jaundice, itching and sepsis may occur.

In order to treat such a disease, balloon dilatation is performed to expand the inner walls of narrowed blood vessels and biliary tract by inserting a balloon catheter or the like into blood vessels and biliary tract.

However, such balloon dilatation has a problem that stenosis may occur after the procedure is narrowed or blocked again due to chronic contraction of neovascularized biliary tract and endothelium proliferation.

In order to solve this problem, Korean Laid-Open Patent Publication No. 2012-0138974 (announced: 2012.12.27, hereinafter referred to as the prior art) after the angioplasty, by inserting the inside of the blood vessels by supporting the inner wall of the vessel, A stent is proposed to prevent stenosis of blood vessels caused by chronic contraction.

However, in the prior art, since the stent supporting the blood vessel is composed of only metal wires, materials such as blood, bile and protein debris passing through the lesion site may be deposited on the stent, and the material passing through the stent may contact the lesion site. There is a problem that can not be prevented, the neo-intima can proliferate into the gap of the wire, the restenosis may occur.

The present invention is to solve the above-mentioned problems, to prevent the deposition of the material passing through the lesion site, close to the blood vessels and biliary tract to protect the lesion site from the material, stenosis of blood vessels and biliary tract due to neoplasia The purpose is to provide a stent to prevent.

In order to achieve the above object, the stent of the present invention includes a tube-like stent body having metal wires intersecting with each other to form a grid or mesh-type mesh and having a hollow therein; A first coating layer formed surrounding the surface of the stent body; And a second coating layer formed on the surface of the first coating layer, wherein the second coating layer is lower than the first coating layer to prevent the material passing through the lesion from adhering to the surface of the first coating layer. It may be formed of a polymer solution having a friction coefficient.

In addition, the first coating layer may be made of at least one composition of medical polyurethane, silicone urethane copolymer, silicone, polyamide, polyester, and fluororesin.

In addition, the second coating layer may be formed by spraying or dipping the polymer solution on the surface of the first coating layer.

On the other hand, the polymer solution may be a silicone polymer solution having the same structural formula, and is produced by a plurality of polymers having a different chain number and a crosslinking agent for bonding the plurality of polymers.

Here, the plurality of polymers may be polysiloxanes containing vinyl groups.

In addition, the crosslinking agent may be polymethylhydrogensiloxane.

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

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

Second, the coating layer formed on the stent can prevent the substance passing through the lesion area of the biliary tract and blood vessels to contact the lesion site through the stent.

Third, by the contact surface of the coating layer formed on the stent to support the biliary tract and the blood vessel inner wall, it is possible to prevent the restenosis of the biliary duct and blood vessels generated by the neointimal penetration into the stent.

1 is a perspective view showing a cross section of the stent and the stent according to an embodiment of the present invention.

Figure 2 is an ASTM D1894-14 measuring equipment for measuring the friction value of the second coating layer of the stent according to an embodiment of the present invention.

Figure 3 is a graph showing the results of measuring the friction value of the silicon coating and the conventional silicon coating to form a second coating layer of the stent according to an embodiment of the present invention.

Figure 4 is a flow chart showing a method of manufacturing a stent in accordance with an embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described in more detail with reference to the accompanying drawings, and the well-known technical parts will be omitted or compressed for brevity of description.

1 is a perspective view of a stent in accordance with an embodiment of the present invention.

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

The stent body 110 has a plurality of metal wires 112 having a wavy shape along the longitudinal direction are connected in various forms such as a lattice, a mesh, and the like, and may have a cylindrical shape having a hollow in the longitudinal direction.

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

In addition, the stent body 110 inserted into the biliary tract and the lesion of the blood vessel may expand in the direction of the biliary tract and the blood vessel to support the inner wall.

The first coating layer 120 is formed to surround the stent body 110 to prevent the substance passing through the biliary tract and the lesion site of blood vessels from directly contacting the lesion site, and the stent body 110 is in the direction of the biliary tract and the blood vessel inner wall. When expanded to support the inner wall, the area in contact with the inner wall is widened to be able to be in close contact with the lesion.

Here, as the composition of the first coating layer 120, at least one polymer solution of medical polyurethane, silicone urethane copolymer, silicone, polyamide, polyester, and fluororesin solution may be used, but is not limited thereto.

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

In addition, the second coating layer 130 has a relatively low coefficient of friction than the first coating layer 120, such that blood, bile, protein residues, etc., passing through the stent 100 installed on the lesion site are stents 100. ) Can be prevented.

In addition, the silicon 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 show a difference in the number of chains constituting the polymer, and two kinds of polysiloxanes containing vinyl groups may be used, and polymethylhydrogensiloxane may be used as a crosslinking agent.

Meanwhile, the silicone solution constituting the second coating layer 130 of the stent 100 may be formed of two types of polysiloxane containing a vinyl group of Formula 1 and a polymethylhydrogensiloxane of Formula 2.

[Revision under Rule 26 03.11.2014]

In this case, the two types of polysiloxane containing a vinyl group may be polysiloxanes having different values of x and y in Structural Formula 1, respectively. In addition, the polysiloxane containing two kinds of vinyl groups may be stirred in a 1: 1 mass ratio.

[Revision under Rule 26 03.11.2014]
Where Me is

Is a methyl group.

[Revision under Rule 26 03.11.2014]

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

[Revision under Rule 26 03.02.2014]

[Revision under Rule 26 03.11.2014]
At this time,

(Vinyl group) and H in Structural Formula 2

It is substituted with (methylene) and combined without additional products such as carbon dioxide and water.

By spraying or immersing the thus produced silicon solution on the surface of the first coating layer 120 and performing a curing process, the second coating layer 130 can be formed.

At this time, by adding a platinum organic compound to the silicone solution, it is possible to accelerate the curing process of the silicone solution.

Figure 2 is an ASTM D1894-14 measuring equipment for measuring the friction value of the second coating layer of the stent according to an embodiment of the present invention, Figure 3 is to form a second coating layer of the stent in accordance with an embodiment of the present invention It is a graph showing the friction value measurement results of the silicone coating and the conventional silicone coating.

As shown in FIG. 2, a silicon thin film forming a second coating layer 130 and a conventional silicon thin film having a size of 50x150 mm are prepared in an ASTM D1894-14 measuring device, and 201.98 g of friction material is 12 inch / min in a lateral direction. The friction value was measured under the condition of moving at a speed of.

In this case, the silicon thin film or the conventional silicon thin film forming the second coating layer 130 of the present invention is placed below the friction material, and the blood measured in the transverse direction when 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 in the graph of FIG. 3 was obtained.

Through the graph of FIG. 3, the minimum friction value, the maximum friction value, and the frictional material of the silicon thin film and the conventional silicon thin film forming the second coating layer 130 of the present invention are maintained at a constant speed and the average friction of the section in which the movement proceeds The value was calculated and the result of Table 1 was obtained.

[Revision under Rule 26 03.11.2014]

As shown in FIG. 3 and Table 1, it was shown that the silicon polymer forming the second coating layer 130 of the present invention has a low friction value in all sections, compared to the conventional silicon.

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

A step of preparing the stent main body 110 is performed to evenly form the first coating layer 120 on the stent main body 110 (S100).

Here, in order to remove the foreign matter adhering to the surface of the stent body 110, using an ultrasonic ethanol and distilled water mixed solvent in an ultrasonic cleaner for 1 hour and dried for 12 to 24 hours in a hot air dryer of 50 ~ 70 ℃.

Subsequently, the first coating layer is formed on the surface of the stent body 110 using a method of immersing, ultrasonic spraying, and electrospinning the composition forming the first coating layer 120.

Here, after applying the solution forming the first coating layer 120 to the stent main body 110, put in a 35 ℃ drying oven and the first drying for 30 minutes, then put in a 180 ° C drying oven 3 hours secondary drying Proceed.

Thereafter, the second coating layer 130 is formed by immersing and spraying the silicone polymer solution on the surface of the dried primary coating layer 120.

At this time, after drying for at least 5 minutes at room temperature for which ventilation is desired, the second solution layer is cured by curing the silicon solution on the surface of the first coating layer 120 by secondary drying for 20 minutes under reduced pressure in a vacuum oven at 150 ° C. to form the second coating layer 130. Can be.

As a result, the present invention protects the lesion site from contact with the substance passing through the stent in the lesion site, and the coating layer is adhered to the inner wall of the lesion site so that the neointimal membrane of the lesion site is generated in the stent. And a stent that prevents material from passing through the lesion site from being deposited on the surface through a low frictional coating layer.

As described above, the detailed description of the present invention has been made by the embodiments with reference to the accompanying drawings. However, since the above-described embodiments have only been described with reference to preferred examples of the present invention, the present invention is limited to the above embodiments. It should not be understood that the scope of the present invention is to be understood by the claims and equivalent concepts described below.

(Explanation of the sign)

100 stent

110: stent body

120: first coating layer

130: second coating layer

Claims

A stent body in the form of a tube having a metal wire intersecting with each other to form a grid or mesh-like mesh and having a hollow therein;

A first coating layer formed surrounding the surface of the stent body; And

And a second coating layer formed on the surface of the first coating layer.

The second coating layer is formed of a polymer solution having a friction coefficient lower than that of the first coating layer to prevent the material passing through the lesion from adhering to the surface of the first coating layer.

Stent.
The method of claim 1,

The first coating layer is made of at least one of the composition of medical polyurethane, silicone urethane copolymer, silicone, polyamide, polyester and fluororesin

Stent.
The method of claim 1,

The second coating layer is formed by spraying or dipping the polymer solution on the surface of the first coating layer

Stent.
The method of claim 1,

The polymer solution has the same structural formula, characterized in that the silicone polymer solution produced by a plurality of polymers having a different number of chains and a crosslinking agent for bonding the plurality of polymers.

Stent.
The method of claim 4, wherein

The plurality of polymers is characterized in that the polysiloxane containing a vinyl group

Stent.
The method of claim 4, wherein

The crosslinking agent is characterized in that the polymethylhydrogensiloxane

Stent.