WO2015174590A1

WO2015174590A1 - Stent

Info

Publication number: WO2015174590A1
Application number: PCT/KR2014/009966
Authority: WO
Inventors: 박도현; 한종현; 김은진; 박헌국; 장봉석; 윤호; 김선종
Original assignee: 주식회사 엠아이텍; 박도현
Priority date: 2014-05-16
Filing date: 2014-10-22
Publication date: 2015-11-19
Also published as: KR20150131716A

Abstract

The present invention relates to a stent comprising: a stent body, in a tube form, which has metal wires intersect so as to form a net in a lattice or a mesh form and which has a hollow inside thereof; and a coating film which is formed by covering the surface of the stent body, wherein the coating film can be formed as a coating solution in which a silicone polymer, provided in a solution form, and hydrophobic polymer particles, having lower coefficient of friction than the silicone polymer, are stirred. The present invention has the advantages of: by means of a coating film having low frictional force, preventing material that passes through a lesion site from being deposited on the surface of a stent; the coating film of the stent preventing lesion cites of a bile duct or a blood vessel from coming in direct contact with material that passes through the stent; by having a contact surface of the coating film formed on the stent support the inner walls of the bile duct and the blood vessel, preventing restenosis of the bile duct and the blood vessel generated due to the proliferation of neointima inside the stent; and being applied to various lesion cites by having wear resistance and flexibility of the existing silicone coated stent maintained as much as possible.

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, and in the case of blood vessels, blood circulation disorders and muscle pain may be caused, and in severe cases, ischemic ulcers You may need to cut the site.

In addition, in the case of biliary tract, a narrowed or closed tumor may cause symptoms such as fever, jaundice, itching, and sepsis when the excretion of bile is not smooth.

In order to treat these diseases, the vascular and biliary tracts are checked by angiography combined with endoscopy and X-ray examination. The catheter is inserted into the vascular and biliary tracts and the biliary tract is narrowed. Dilation of the blood vessels and biliary tracts is being done.

However, such dilatation may result in temporary improvement due to chronic contraction of vascular and biliary tract and proliferation of neovascularization, but there is a problem that stenosis may occur again after the procedure is narrowed or blocked.

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, substances such as blood, bile, and protein debris that pass through the lesion site may be deposited on the stent, thereby preventing the flow of blood and body fluids. The passing material may be in contact with the lesion site, the lesion site may deteriorate, and there may be a problem in that the neointimal proliferation into the stent through the gap of the wire may occur.

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

In order to achieve this 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 net and having a hollow therein; And a coating film formed to surround the surface of the stent body. The coating film may be formed of a coating solution in which a silicon polymer provided in a solution form and hydrophobic polymer particles having a lower friction coefficient than the silicon polymer are stirred.

In addition, the shape memory alloy constituting the stent main body may be Nitinol having a main component of nickel (Ni) and titanium (Ti).

In addition, the coating solution may be prepared by adding the hydrophobic polymer particles of 7wt% or less to the silicone polymer solution.

In addition, the hydrophobic polymer particles may be PTFE (Poly tetra fluoro ethylene) particles having a friction coefficient of 0.05 ~ 0.20N.

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

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

Secondly, the coating film formed on the stent can prevent the material passing through the biliary tract and the lesion site of the blood vessel from contacting the lesion site through the stent.

Third, by the contact surface of the coating film 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 tract and blood vessels generated by the neointimal proliferation into the stent.

Fourth, while containing the PTFE particles to minimize the deposition of the material, the silicone can be applied to a variety of lesions by minimizing the wear resistance and elasticity of the coating film.

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

Figure 2 is a graph showing the tensile strength and elongation of the coating film and the conventional silicon coating film with different amounts of PTFE particles added to the coating solution to form a coating film of the stent according to an embodiment of the present invention.

Figure 3 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.

<< 스텐트의 구성Composition of the stent >>

The stent 100 according to an embodiment of the present invention may include a stent main body 110 composed of a metal wire 112, a coating film 120 formed of a silicon polymer 122 and PTFE particles 124. .

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.

In addition, as the metal wire 112 constituting the stent main body 110, Nitinol, which is a nickel (Ni) -titanium (Ti) alloy, is used, and the stent main body 110 expands or contracts in a circumferential direction at a specific temperature. As a result, 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 blood vessel to support the inner wall.

The coating film 120 is formed to surround the surface of the stent body 110 to prevent the material passing through the stent 100 installed on the lesion site from contacting the lesion site.

Here, the coating film 120 may be formed of a coating solution in which the PTFE particles 124, which are prepared by stirring the PTFE particles 124 in the solution-type silicone polymer 122, are evenly dispersed.

The silicon polymer 122 may have a tensile strength of 14.6 N and an elongation of 940%.

The PTFE particles 124 may be made of poly tetra fluoro ethylene (PTFE) in powder form.

Here, PTFE is a hydrophobic fluorine-based polymer having a low coefficient of friction of 0.05-0.20 N.

Meanwhile, the PTFE particles 124 added to the silicon polymer 122 in a solution form may be 7 wt% or less, which will be described with reference to FIG. 2.

In FIG. 2, the tensile strength (N) and the elongation (%) of the comparison group and the silicone polymer 122 in which the content ratio of the PTFE (124) particles in the solution-type silicone polymer 122 is different from each other are shown in Table 1 below. Represented by.

Referring to Table 1, it can be seen that the coating film formed only of the silicon polymer 122 has a tensile strength of 14.6N and an elongation of 940%.

Here, the coating film 120 formed on the stent 100 of the present invention to minimize the drop in the tensile strength and elongation of the silicone polymer 122, the blood, bile and protein residues are deposited in the stent 100 For prevention, it is preferable to form the coating film 120 using a coating solution in which 7 wt% or less of PTFE particles 124 are added to the silicon polymer 122 in a solution form.

Therefore, the stent 100 having the coating film 120 having excellent hydrophobicity, abrasion resistance, and elasticity may be applied to various lesion sites regardless of blood vessels and biliary tract structures.

<< 스텐트의 제조방법Manufacturing method of stent >>

1. One. 스텐트 본체 준비단계Stent Body Preparation Step (S100) (S100)

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

Here, the stent main body 110 may be manufactured by heat-treating a metal wire 112 of a nitinol material having a diameter of about 50 to 150 microns in a net form on an iron cylinder. Here, it is preferable to perform heat processing for 20 to 40 minutes at the temperature of 400-500 degreeC.

Then, after the heat treatment is completed, the stent main body 110 is completely cooled, so that the coating film 120 is evenly formed on the surface of the stent main body 110, using a mixed solvent of ethanol and distilled water in an ultrasonic cleaner for 1 hour to stent After removing the foreign matter adhering to the surface of the main body 110, and dried for 12 to 24 hours in a hot air dryer of 50 ~ 70 ℃, the dried stent main body 110 is inserted into the coating jig to form the coating film 120 The process may include.

In addition, the stent main body 110 may be manufactured by processing the metal in the form of a tube by laser cutting.

2. 2. 코팅용액 준비단계Coating Solution Preparation Step (S200) (S200)

Thereafter, a step of preparing a coating solution for forming the hydrophobic coating film 120 on the stent body 110 is performed.

Here, the coating solution may be prepared by adding sufficient PTFE particles 124 in a concentration of 7wt% or less to the silicon polymer 122 in the form of a solution, followed by sufficient stirring so that the PTFE particles 124 may be evenly dispersed. .

3. 3. 코팅막 형성단계Coating film forming step (S300) (S300)

Applying the prepared coating solution to the surface of the stent body 110 mounted on the coating jig is made (S300).

Here, the coating solution may be applied to the stent body 110 by dipping, brushing, spraying, electrospinning, or the like.

Thereafter, the coating solution is applied to the stent main body 110 is put into a drying oven at 35 ℃ and the first drying for 30 minutes, and then put into a 180 ℃ drying oven and dried for 3 hours.

The stent 100 of the present invention may be manufactured by separating the stent 100 from which the coating film 120 is dried, from the coating jig.

As a result, the present invention prevents the material passing through the lesion site from being deposited on the surface through the coating film having a low frictional force, and can be applied to various lesion sites by minimizing the wear resistance and elasticity of the existing silicone coating film. It is installed on the lesion site to protect the lesion site from contact with the material passing through the stent and provides a stent to prevent the growth of the neo-intima of the lesion site within the stent by the coating film closely supports the inner wall of the lesion site. .

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

112: metal wire

120: coating film

122: silicon polymer

124: PTFE Particles

Claims

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

It includes; coating film formed to surround the surface of the stent body,

The coating film is formed of a coating solution agitated with a silicon polymer provided in a solution form and hydrophobic polymer particles having a lower friction coefficient than the silicon polymer.

Stent.
The method of claim 1,

The metal wire constituting the stent main body is characterized in that the Nitinol (Nitinol) mainly composed of nickel (Ni) and titanium (Ti)

Stent.
The method of claim 1,

The coating solution is prepared by adding the hydrophobic polymer particles of 7wt% or less to the silicone polymer solution.

Stent.
The method of claim 1,

The hydrophobic polymer particles are characterized in that the PTFE (Poly tetra fluoro ethylene) particles having a friction coefficient of 0.05 ~ 0.20N

Stent.