KR102512526B1 - Manufacturing method of stent for coronary artery containing biodegradable magnesium and stent manufactured by the manufacturing method - Google Patents

Abstract

The present invention relates to a manufacturing method of a coronary stent made of an alloy containing biodegradable magnesium and a stent manufactured by the manufacturing method. More specifically, a technical field related to a manufacturing method of a coronary stent containing biodegradable magnesium and a stent manufactured by the manufacturing method is disclosed. According to the manufacturing method, a magnesium alloy is extruded into a shape of a round bar and the round bar-shaped magnesium alloy is cut with a drill and bite and processed into a thin tube, and then a mesh-shaped stent is manufactured through patterning using a laser. In addition, tips or burrs generated during patterning are removed through electropolishing, and then a biodegradable coating layer is formed on a surface of the stent. Accordingly, the thin tube can be manufactured stably and precisely.

Description

Manufacturing method of stent for coronary artery containing biodegradable magnesium and stent manufactured by the manufacturing method}

The present invention relates to a method for manufacturing a stent for a coronary artery made of an alloy containing biodegradable magnesium and to a stent manufactured by the manufacturing method. After cutting the magnesium alloy into a thin tube by cutting it with a drill and a bite, a stent in the form of a net is manufactured through patterning using a laser, and the tip or burr generated during patterning is removed through electropolishing, and then the surface of the stent is biodegradable. It relates to a method for manufacturing a stent for a coronary artery containing biodegradable magnesium forming a coating layer and a stent manufactured by the manufacturing method.

In general, blood vessels including coronary arteries, basilar arteries, cerebral arteries, and the like are surrounded by endothelial cells on the innermost side. At this time, endothelial cells react to allow blood to flow smoothly, and blood clots or waste products of lipid components form on the walls of blood vessels due to various causes such as damage to endothelial cells, geometric shape of blood vessels, stiffness of blood vessels, and cardiovascular diseases. As it accumulates, stenosis occurs, which narrows the inner diameter of blood vessels.

When such stenosis develops in blood vessels, the metabolism caused by blood flow is significantly reduced, and the heart works excessively to supply blood to capillaries through blood vessels with narrowed inner diameters, which intensifies the symptoms of hypertension. In particular, when the supply of oxygen to the myocardium becomes scarce due to stenotic lesions in the coronary arteries of the heart, necrosis of the myocardium progresses and myocardial infarction occurs.

In order to treat the stenosis as described above, an interventional procedure of inserting a stent to expand the inner diameter of the blood vessel to facilitate blood flow by inserting a stent into the narrowed blood vessel should be performed. The interventional procedure is a procedure of physically expanding the inner diameter of a blood vessel by expanding the diameter of the stent while injecting air into the balloon in a state where a stent with a built-in balloon is inserted into the inside of a blood vessel using a conduit.

Stents were first introduced in 1977 at the University Hospital of Zurich, Switzerland, in which a patient suffering from severe angina pectoris used a balloon to widen a blood vessel. Currently, when the flow of blood or body fluids such as blood vessels, esophagus, gastrointestinal tract, and bile duct is not smooth due to the occurrence of malignant or benign diseases, surgical operation is not performed. It is used as a medical tool to normalize the flow of bodily fluids or bodily fluids.

The initially developed stent is made of a metal material and has a simple structure in which the outer diameter is enlarged by a balloon. In addition, there is a problem in that restenosis occurs due to wounds occurring in blood vessels during transplantation and the action of platelets due to an inflammatory reaction.

In order to solve the problems of conventional metal stents, a stent (drug eluting stent: 　DES) coated with an antithrombotic agent to prevent clots from forming on the surface has been developed, but the effect is insignificant due to various variables.

As another method for solving the problems of the conventional metal stent, a biodegradable stent technology that is naturally degraded after a certain time elapses in the body is being developed. For example, Korean Patent Publication No. 2017-0019803 has proposed a biodegradable stent technology.

Biodegradable stent products may be divided into several product groups according to the type of biodegradable polymer forming the scaffold of the stent. Among them, a stent made of magnesium has excellent mechanical properties compared to other polymers, and when magnesium is biodegraded in the body, it can be absorbed into the body as a beneficial mineral, so it is a material that has recently been in the spotlight.

In addition, magnesium (Mg) has a specific gravity (density g/cm, 20°C) of 1.74, is the lightest metal among metal materials used for structural purposes, and can increase strength by adding various elements and alloying. . In addition, since magnesium alloys have a relatively low melting point and require little energy during recycling, they are also preferable from the viewpoint of recycling and are expected as a substitute for resin materials.

More specifically, magnesium (Mg) or an alloy containing magnesium as a main component (hereinafter collectively referred to as a 'magnesium alloy') has good specific strength, dimensional stability, machinability, vibration absorption, etc., is light in weight and has high strength. It is high and has good affinity to the human body. Accordingly, magnesium (Mg) or an alloy containing magnesium as a main component has recently been used for transportation devices such as automobiles, railroads, aircraft, and ships, cases for various portable electronic devices, sports and leisure equipment, welfare devices, home appliances, medical devices, It can be applied to various fields that require light weight and biodegradable characteristics such as household goods, and is in the limelight as a core material in the industry.

In connection with the above, stents containing magnesium alloy as a main component are mainly manufactured by a casting method that performs injection molding such as die casting or thixo-molding because magnesium alloy has an hcp structure with poor plastic workability.

However, stents whose main components are magnesium alloys cast by injection molding as described above lack mechanical properties such as tensile strength, ductility, and toughness, and are difficult to obtain for molded articles such as runners for introducing molten metal into molds. Since a large amount of unnecessary parts are generated, the material yield is poor, and air bubbles are formed inside the molded product due to the involvement of air bubbles during molding, and there are cases where heat treatment cannot be performed after molding, and streamlines, pores, and burrs may occur. Since there are casting defects such as casting defects, correction or removal work is required, and since the release agent applied to the mold adheres to the molded product, the removal work is necessary, production equipment is expensive, and the existence of the above unnecessary parts However, there is a problem in that the manufacturing cost is high due to the removal work.

In order to solve the above problems, a stent containing a magnesium alloy as a main component has recently been manufactured by extruding the magnesium alloy into a wire form and then bending the wire to make a body of the stent.

However, to manufacture a stent made of magnesium by bending a wire to make a body of the stent, the brittleness of magnesium itself is large, so there is a concern that the wire may be easily broken while bending the wire, and workability is deteriorated. .

Accordingly, as a method for solving the problem of a stent having a wire-type magnesium alloy as a main component, a magnesium material is first manufactured in a tube shape having a predetermined diameter, and then the surface of the tube is laser-cut to obtain laser A method for manufacturing a cut-type stent has been devised, but due to the nature of magnesium, which lacks plastic workability, there is a problem in that it is difficult to manufacture the stent in the form of a tube of a predetermined diameter, that is, a thin shape.

Republic of Korea Patent Publication No. 10-2017-0019803 (registered on July 20, 2017)

The present invention is a technique devised to solve the problems according to the prior art described above, and the stent manufactured after first being manufactured in a conventional tube form is manufactured in a predetermined diameter, that is, a thin tube form due to the nature of magnesium lacking in plastic workability. Difficult problems, in particular, in the case of extrusion and drawing, breakage and deformation during drawing frequently occur,

An alloy containing magnesium (Mg) as a main component (hereinafter collectively referred to as 'magnesium alloy') is extruded into a round bar shape, and an inner diameter is formed by cutting the inside of the round bar shape magnesium alloy with a drill, and the inner diameter is formed with a bite. Cutting the outside of the formed magnesium alloy, using a guide jig and a guide pin to stably and precisely manufacture a thin magnesium tube, then patterning using a laser to manufacture a mesh-shaped stent, and removing the tip or burr generated during patterning A main object of the present invention is to provide a method for manufacturing a stent for coronary artery containing biodegradable magnesium that is removed through electropolishing and then forms a biodegradable coating layer on its surface, and a stent manufactured by the method.

In order to realize the above-described object, the present invention includes a tube manufacturing step (S100) of manufacturing a round bar-shaped magnesium alloy 10 into a thin tube; and a stent 100 by forming a pattern on the thin tube using a laser. A laser patterning step (S200) of manufacturing; and an electropolishing step (S300) of removing the tip or burr formed on the stent 100 in the tube manufacturing step (S100) and the laser patterning step (S200); and a coating step (S400) of forming a biodegradable coating layer on the surface of the stent 100 after the electrolytic polishing step (S300); present.

In addition, the tube manufacturing step (S100) of the present invention is a first cutting step (S10) of forming a processing hole 12 by cutting the rear inner side of the round bar-shaped magnesium alloy 10 with a drill 24; and A second cutting step (S20) of turning the rear outer side of the magnesium alloy 10 after the first cutting step (S10) into a bite 33; characterized in that it is configured to include.

In addition, the first cutting step (S10) of the present invention includes a first inner diameter forming step (S12) of forming a processing hole 12 by cutting the rear inner side of the magnesium alloy 10 with a first drill; and the magnesium A second inner diameter forming step (S14) of expanding the processing hole 12 by cutting the rear inner side of the alloy 10 with a second drill having a larger outer diameter than the first drill.

In addition, in the first cutting step (S10) of the present invention, the rear inner side of the magnesium alloy 10 is cut with a third drill having a larger outer diameter than the second drill to form a third inner diameter to expand the processing hole 12. It is characterized in that it is configured to include; step (S16).

In addition, the first cutting step (S10) of the present invention is characterized in that the difference in the outer diameters of the second drill and the third drill is smaller than the difference in the outer diameters of the first drill and the second drill.

In addition, in the first cutting step (S10) of the present invention, a guide jig 25 in which a guide hole corresponding to the outer diameter of the drill 24 is formed at the rear of the magnesium alloy 10 is installed, and the guide jig It is characterized in that the drill 24 is guided through the guide hole of (25).

In addition, the second cutting step (S20) of the present invention includes a first outer diameter forming step (S22) of turning the rear outer side of the magnesium alloy 10 with a bite 33; and the rear outer side of the magnesium alloy 10 Turning with a bite 33, the second outer diameter forming step (S24) having a cutting thickness smaller than the first outer diameter forming step (S22); and turning the rear outer side of the magnesium alloy 10 with a bite 33 , a third outer diameter forming step (S26) in which the cutting thickness is smaller than the second outer diameter forming step (S24); And turning the rear outer side of the magnesium alloy 10 with a bite 33, the final outer diameter forming step (S28) having a cut thickness smaller than the third outer diameter forming step (S26); characterized in that it is configured to include a .

In addition, the final outer diameter forming step (S28) of the present invention is characterized in that the rear outer side of the magnesium alloy 10 is turned with a cutting thickness of 0.01 to 0.1 mm.

In addition, in the second cutting step (S20) of the present invention, after inserting the guide pin 34 corresponding to the processing hole 12 formed in the first cutting step (S10) into the processing hole 12, the bite ( 33) characterized in that the rear outer side of the magnesium alloy 10 is turned.

The method for manufacturing a stent for coronary arteries containing biodegradable magnesium according to the present invention presented above and the stent manufactured by the manufacturing method are alloys containing magnesium (Mg) as a main component extruded in a round bar shape (hereinafter referred to as 'magnesium alloys'). ') to form an inner diameter using a drill, but minimize the vibration of the drill through a guide jig so that the inner diameter is stably formed, and turn the outside of the magnesium alloy on which the inner diameter is formed using a bite. However, by inserting a guide pin inside the magnesium alloy with an inner diameter, it not only enables stable turning when turning using a bite, but also minimizes the decrease in strength of the material to produce the effect of stably and precisely manufacturing a thin tube. You can get it.

In addition, when cutting using a drill or a bite, the present invention not only cuts accurately by cutting a number of times, but also minimizes the decrease in strength of the material by gradually reducing the thickness to be cut to more precisely set the thickness. Thus, the effect of stably and precisely manufacturing a thin tube can be obtained.

In addition, according to the present invention, as described above, stably and precisely manufactures a thin magnesium alloy tube, so that cutting by laser patterning to be performed later can be stably and easily performed.

1 is a flow chart schematically showing a stent manufacturing method according to a preferred embodiment of the present invention.
Figure 2 is a flow chart showing in detail a stent manufacturing method according to a preferred embodiment of the present invention.
Figure 3 is a view schematically showing a first cutting step according to a preferred embodiment of the present invention.
Figure 4 is a view schematically showing a second cutting step according to a preferred embodiment of the present invention.
Figure 5 is a perspective view showing a stent manufactured by a preferred embodiment of the present invention.
Figure 6 is a side view showing a stent according to a preferred embodiment of the present invention.
7 is a partial plan view of an expanded stent according to a preferred embodiment of the present invention.
8 is a partial plan view of an expanded stent according to another embodiment of the present invention.
9 is a partially enlarged view of FIG. 8;

The present invention relates to a method for manufacturing a stent for a coronary artery made of an alloy containing biodegradable magnesium (hereinafter collectively referred to as 'magnesium alloy 10') and a stent manufactured by the manufacturing method, and more specifically To explain, after extruding the magnesium alloy 10 in the form of a round bar, cutting it to a certain length, fixing the cut magnesium alloy 10 to the fixed chuck 40, and then cutting the inside with a drill 24, that is, the inner diameter, The processing hole 12 is formed, but the vibration of the drill 24 is minimized through the guide jig 25 so that the processing hole 12 is stably formed, and the processing hole 12 is formed. Magnesium alloy 10 Turning the outside using a bite 33, inserting the guide pin 34 into the processing hole 12 and then turning to manufacture a thin tube, and then patterning the thin tube using a laser, that is, cutting A stent for coronary artery containing biodegradable magnesium that manufactures a stent 100 in the form of a net through a method, removes tips or burrs generated during patterning through electropolishing, and forms a biodegradable coating layer on the surface of the stent 100. It relates to a manufacturing method and a stent manufactured by the manufacturing method.

The method for manufacturing a stent for a coronary artery containing biodegradable magnesium of the present invention as described above includes a tube manufacturing step (S100) of manufacturing a round bar-shaped magnesium alloy 10 into a thin tube; and a pattern on the thin tube using a laser A laser patterning step (S200) of manufacturing the stent 100 by forming; and an electrolytic polishing step of removing the tip or burr formed on the stent 100 in the tube manufacturing step (S100) and the laser patterning step (S200) ( S300); and a coating step (S400) of forming a biodegradable coating layer on the surface of the stent 100 after the electrolytic polishing step (S300).

In addition, the tube manufacturing step (S100) of the present invention is a first cutting step (S10) of forming a processing hole 12 by cutting the rear inner side of the round bar-shaped magnesium alloy 10 with a drill 24; and A second cutting step (S20) of turning the rear outer side of the magnesium alloy 10 after the first cutting step (S10) into a bite 33; characterized in that it is configured to include.

In addition, the first cutting step (S10) of the present invention includes a first inner diameter forming step (S12) of forming a processing hole 12 by cutting the rear inner side of the magnesium alloy 10 with a first drill; and the magnesium A second inner diameter forming step (S14) of forming a processing hole 12 by cutting the rear inner side of the alloy 10 with a second drill having a larger outer diameter than the first drill; characterized in that it is configured to include.

In addition, in the first cutting step (S10) of the present invention, a third inner diameter is formed to form a processing hole 12 by cutting the rear inner side of the magnesium alloy 10 with a third drill having a larger outer diameter than the second drill. It is characterized in that it is configured to include; step (S16).

In addition, the first cutting step (S10) of the present invention is characterized in that the difference in the outer diameters of the second drill and the third drill is smaller than the difference in the outer diameters of the first drill and the second drill.

In addition, in the first cutting step (S10) of the present invention, a guide jig 25 in which a guide hole corresponding to the outer diameter of the drill 24 is formed at the rear of the magnesium alloy 10 is installed, and the guide jig It is characterized in that the drill 24 is guided through the guide hole of (25).

In addition, the second cutting step (S20) of the present invention includes a first outer diameter forming step (S22) of turning the rear outer side of the magnesium alloy 10 with a bite 33; and the rear outer side of the magnesium alloy 10 Turning with a bite 33, the second outer diameter forming step (S24) having a cutting thickness smaller than the first outer diameter forming step (S22); and turning the rear outer side of the magnesium alloy 10 with a bite 33 , a third outer diameter forming step (S26) in which the cutting thickness is smaller than the second outer diameter forming step (S24); And turning the rear outer side of the magnesium alloy 10 with a bite 33, the final outer diameter forming step (S28) having a cut thickness smaller than the third outer diameter forming step (S26); characterized in that it is configured to include a .

In addition, the final outer diameter forming step (S28) of the present invention is characterized in that the rear outer side of the magnesium alloy 10 is turned with a cutting thickness of 0.01 to 0.1 mm.

In addition, in the second cutting step (S20) of the present invention, after inserting the guide pin 34 corresponding to the processing hole 12 formed in the first cutting step (S10) into the processing hole 12, the bite ( 33) characterized in that the rear outer side of the magnesium alloy 10 is turned.

The stent for coronary artery containing biodegradable magnesium of the present invention as described above is characterized in that it is manufactured by the manufacturing method of the stent for coronary artery containing biodegradable magnesium as described above.

Hereinafter, a method for manufacturing a stent for a coronary artery containing biodegradable magnesium will be described with reference to FIGS. 1 to 9 illustrating an embodiment of the present invention.

First, the method of manufacturing a stent for a coronary artery containing biodegradable magnesium of the present invention includes an extrusion step of extruding the magnesium alloy 10 into a round bar shape before the tube manufacturing step (S100).

The extruding step is to extrude the magnesium alloy 10 in the form of a round bar through an extruder, extruding the magnesium alloy 10 into a round bar shape having a larger diameter than the outer diameter of the stent 100 to be manufactured, and at this time, the magnesium alloy in the form of a round bar to be extruded (10) is extruded to a diameter greater than about 1.0 to 6 mm than the outer diameter of the stent 100 to be manufactured so that the inner and outer diameters can be formed smoothly. More preferably, it is preferably extruded with a large diameter of 1.0 to 3 mm, and in order to improve productivity, it may be extruded in a round bar shape of about 5 mm or 10 mm regardless of the thickness of the thin tube to be manufactured.

On the other hand, the magnesium alloy of the present invention is characterized by a corrosion rate of 1.0 mm/year (mmpy) based on a 3.5% NaCl solution immersion test, considering the case where the thickness of a typical stent is about 0.3 mm, This is because a stent of normal thickness must dilate the coronary artery for at least 3 to 4 months.

More preferably, the magnesium alloy of the present invention is characterized in that the corrosion rate is 0.1 to 0.3 mmpy depending on the normal thickness of the stent (about 0.2 to 0.5 mm) based on 3.5% NaCl solution immersion test, which more stably This is so that the stent having a normal thickness can expand the coronary artery for about 6 to 12 months or about 1 year or more depending on the characteristics of the affected area.

The magnesium alloy of the present invention having the above corrosion rate is Al: 0.03 to 16.0% by weight, Mn: 0.015 to 1.0% by weight, Sc: 0.02 to 0.5% by weight, lanthanide rare earth elements, based on 100% by weight of the total magnesium alloy (RE): 0.1 to 1.0% by weight, and the balance includes Mg and unavoidable impurities, wherein the rare earth element (RE) is La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er , Tm, Yb or combinations thereof.

In addition, the magnesium alloy of the present invention further comprises 0.1 to 4.5% by weight of Zn based on 100% by weight of the total magnesium alloy.

In addition, the magnesium alloy of the present invention further comprises 0.5 to 2.0% by weight of Ca based on 100% by weight of the total magnesium alloy.

In addition, the magnesium alloy of the present invention further comprises Y: greater than 0 and less than 0.3% by weight based on 100% by weight of the total magnesium alloy.

More specifically, the aluminum contributes to increase the strength of the alloy through solid solution strengthening and precipitation hardening, and serves to improve corrosion resistance by improving the stability of the oxide film during corrosion.

Accordingly, if the aluminum content is too small, the effect of increasing strength and corrosion resistance cannot be expected, and if the aluminum content is too large, the fraction of brittle particles containing aluminum is excessive, causing a problem of weakening the ductility of the alloy. Therefore, the aluminum is preferably included in a composition ratio of 0.03 to 16% by weight based on 100% by weight of the total magnesium alloy.

Manganese not only contributes to increase the strength of the alloy by solid solution strengthening, etc., but also contributes to improving the corrosion resistance of the magnesium alloy by forming compound particles that absorb impurities in the alloy. However, if the content of manganese is too small, the effect of increasing strength and improving corrosion resistance may be insignificant.

In addition, the corrosion resistance improvement effect can be obtained even in the magnesium alloy material containing manganese and scandium. However, if too much manganese is added to the magnesium alloy material containing scandium, the proportion of particles containing manganese is excessive, and microgalvanic corrosion is rather promoted, thereby degrading corrosion resistance, and the proportion of particles containing manganese is excessive. Since elongation may decrease during plastic deformation of the alloy, manganese may be included in a composition ratio of 0.015 to 1.0% by weight, more preferably 0.015 to 0.6% by weight, based on 100% by weight of the total magnesium alloy. do.

The scandium serves to improve the corrosion resistance of the magnesium alloy material by being involved in the change in the electrochemical properties of the secondary phase particles.

Accordingly, if the scandium content is too small, the degree of change in the electrochemical properties of the secondary phase particles containing scandium is small, and it may be difficult to expect the effect of adding scandium to improve corrosion resistance. On the other hand, if the content of scandium is too large, the fraction of particles containing scandium is excessive, which may cause problems of accelerating microgalvanic corrosion and increasing the price of alloy materials. In addition, since irregularities may occur on the surface of the cast material when the content of scandium is excessive, the scandium is preferably included in a composition ratio of 0.02 to 0.5% by weight with respect to 100% by weight of the entire magnesium alloy.

The rare earth element may improve corrosion resistance by being involved in changes in the electrochemical properties of secondary phase particles. Specifically, in one embodiment of the present invention, the rare earth element (RE) is a lanthanide rare earth element as an element La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb or a combination thereof. Among the rare earth elements, when the element is added, the effect of improving corrosion resistance may be excellent.

That is, by adding scandium and a lanthanide rare-earth element excluding scandium to the magnesium alloy of the present invention, the effect of improving stone resistance can be further expected.

Accordingly, if the content of the rare earth element is too small, the corrosion resistance improvement effect may be insignificant, and if the content is too large, the alloy manufacturing cost may excessively increase. It is preferably included in the composition ratio.

Like aluminum, zinc serves to increase the strength of the alloy through solid solution hardening and precipitation hardening.

Accordingly, if the content of zinc is too small, the effect of increasing strength cannot be expected, making it difficult to use it as a structural material. On the other hand, if the zinc content is too large, the fraction of zinc-containing particles is excessive and microgalvanic corrosion may be promoted. Therefore, the zinc is included in a composition ratio of 0.1 to 4.5% by weight based on 100% by weight of the total magnesium alloy.

The calcium serves to increase the ignition resistance temperature of the magnesium alloy.

Accordingly, if the content of calcium is too small, the ignition resistance of the alloy is low, so the use of an expensive shielding gas to suppress ignition may be required, which may increase the manufacturing cost of the alloy. On the other hand, if the content of calcium is too large, the fraction of particles containing calcium is excessive, and cracks may occur due to stress concentration around the particles during plastic working of the alloy. In addition, since the fraction of the particles containing calcium is excessive, microgalvanic corrosion may be promoted, the calcium is included in a composition ratio of 0.5 to 2.0% by weight with respect to the total 100% by weight of the magnesium alloy.

The yttrium, like calcium, serves to increase the ignition resistance temperature of the magnesium alloy.

Accordingly, when too little yttrium is added, the effect of improving ignition resistance may be insignificant because the ignition temperature is low. On the other hand, if the content of yttrium is too large, the fraction of the particles containing yttrium is excessive, which can cause problems of accelerating microgalvanic corrosion and increasing the price of alloy materials. For, it is included in a composition ratio of more than 0 and 0.3% by weight or less.

On the other hand, as an example of the magnesium alloy of the present invention, Mg-3Al-0.3Mn-0.1Sc-1Zn alloy Microstructure analysis shows that Al-Mn-Fe-based particles and Al-Mn-Sc particles containing impurity Fe are formed therein.

Through this microstructure analysis, when a rare earth element such as Gd is added to the Mg-3Al-0.3Mn-0.1Sc-1Zn alloy, the particles containing impurity Fe are located in the center and the Al-Mn-RE particles are located outside the core- It can be seen that double particles in the form of a core-shell are formed.

In general, particles containing Fe are known to activate microgalvanic corrosion in magnesium alloys due to their high electrochemical potential. Therefore, these particles do not activate microgalvanic corrosion, and thus the corrosion resistance of the alloy can be improved.

As such, the magnesium alloy of the present invention has excellent corrosion resistance, strength, and corrosion resistance compared to pure magnesium, and thus can be easily used as a stent requiring biodegradation characteristics.

Next, the present invention includes a separation step of cutting the magnesium alloy 10 after the extrusion step, that is, the magnesium alloy 10 in the form of a round bar to a predetermined length.

The separation step may have a front length that can be stably fixed to the fixed chuck 40 used in the first cutting step (S10) and the second cutting step (S20) after the extruding step and a rear length in which a tube is formed. The magnesium alloy 10 in the form of a round bar is cut to a certain length so as to be. At this time, since the predetermined length varies depending on the length of the fixed chuck 40 and the tube to be manufactured, it will be apparent that it is a predetermined length during manufacturing.

Next, the present invention is configured to include a tube manufacturing step (S100) of manufacturing the round bar-shaped magnesium alloy 10 into a thin tube after the separation step.

Specifically, the tube manufacturing step (S100) is a first cutting step (S10) of forming an inner diameter, that is, a processing hole 12 by cutting the inner rear side of the round bar-shaped magnesium alloy 10 with a drill 24, After the first cutting step (S10), it is configured to include a second cutting step (S20) of finally forming the thickness of the tube by turning the rear outer side of the round bar-shaped magnesium alloy 10 with a bite 33.

In the first cutting step (S10), the round bar cut to a predetermined length in the separation step prior to forming the processing hole 12 by cutting the rear inner side of the magnesium alloy 10 with the drill 24 with the drill 24. It is configured to include a fixing step of fixing the front of the magnesium alloy 10 of the form to the rear of the fixing chuck 40.

In addition, the cutting device used in the first cutting step (S10) is located at the front, fixes the front of the round bar-shaped magnesium alloy 10 to the rear, is movable forward and backward, and is rotatable. 40); and a drill unit 20 installed at the rear of the fixed chuck 40; and the drill unit 20 is installed at the rear of the fixed chuck 40. The base frame 21 ); And, a drill body 22 installed movably forward and backward on the upper part of the base frame 21; And, a drill chuck 23 installed in front of the drill body 22; and a drill 24 detachably coupled to the front of the drill chuck 23.

At this time, the base frame 21 is installed on the top, is installed to be positioned in front of the drill body 22, and includes a guide jig 25 in which a guide hole corresponding to the outer diameter of the drill 24 is formed. As the drill 24 is penetrated and installed in the guide jig 25, the fixing chuck 40 is rotated and moved backward to cut the magnesium alloy 10 by the drill 24. When, that is, when the processing hole 12 is formed, vibration is reduced so that cutting can be performed more stably.

In relation to the above, in the first cutting step (S10), after the round bar-shaped magnesium alloy 10 after the separation step is fixed to the fixed chuck 40, the rear inner side of the magnesium alloy 10 is used with a first drill. A first inner diameter forming step (S12) of forming the processing hole 12 by cutting, and a second drill having a larger outer diameter than the first drill on the rear inner side of the magnesium alloy 10 after the first inner diameter forming step (S12). It is configured to include a second inner diameter forming step (S14) of replacing with a drill and cutting with the second drill to expand the processing hole 12.

The first cutting step (S10) is not to form the inner diameter, that is, the processing hole 12 at once, but through the first inner diameter forming step (S12) and the second inner diameter forming step (S14), that is, the inner diameter forming step twice. It is possible to form the processing hole 12 stably and accurately.

In addition, in the first cutting step (S10), after the second inner diameter forming step (S14), the rear inner side of the magnesium alloy 10 is replaced with a third drill having a larger outer diameter than the second drill and is cut with the third drill. It constitutes a third inner diameter forming step (S16) to expand the processing hole (12).

That is, in the first cutting step (S10), the processing hole 12 is gradually formed through the first inner diameter forming step (S12) and the second inner diameter forming step (S14) as well as the third inner diameter forming step (S16). By expanding through three steps, it is possible to manufacture the inner diameter of the thin tube that is required more precisely and stably, that is, the inner diameter of the stent 100 to be manufactured by forming the processing hole 12.

In addition, the reason why the first cutting step (S10) performs the three-step cutting step is that it may be advantageous to form the inner diameter of the magnesium alloy 10 more precisely and stably when performing more steps. , The process of work is too many, so not only the working time is increased, but also a lot of shock is transmitted to the magnesium alloy 10 during cutting, which can reduce durability, and the first inner diameter forming step (S12) or the second inner diameter forming step ( This is because, in the case of performing only up to S14), irregularities may occur on the inner circumferential surface of the magnesium alloy 10 due to poor precision.

In addition, the first cutting step (S10) is characterized in that the outer diameter size difference between the second drill and the third drill is smaller than the outer diameter size difference between the first drill and the second drill, which gradually reduces the thickness of the magnesium alloy ( 10), it is possible to minimize irregularities on the inner circumferential surface of the magnesium alloy 10 and to obtain an effect of more precisely cutting a required thickness.

In addition, in the first inner diameter forming step (S12), it is preferable to set the rotational speed of the first drill to a speed of 1500 rpm or less, which is when the rotational speed of the first drill exceeds 1500rpm. This is because the magnesium alloy 10 in the form of a round bar of the present invention having a relatively small diameter compared to cutting using a general drill during formation may be twisted or damaged.

In this regard, in the second inner diameter forming step (S14) and the third inner diameter forming step (S16), it is preferable to set the rotational speed of the second drill and the third drill to a speed of more than 1500 rpm and less than 3600 rpm, respectively. This is to minimize the temperature generated during cutting by cutting the magnesium alloy 10 at a speed and to smoothly form the inner circumferential surface of the magnesium alloy 10.

In addition, since the first inner diameter forming step (S12) as well as the second inner diameter forming step (S14) and the third inner diameter forming step (S16) are cut by rotating the drill 24 at a very high speed, the temperature during cutting is generated at less than about 50 degrees, so there is no need to use cutting oil, and thus an effect of reducing an unnecessary process of removing cutting oil can be obtained.

In addition, the drill 24 is preferably made of a material that is harmless to the human body, which can be worn when cutting. For example, any of cobalt, chromium, carbide, STS, nickel, SKD, SCM, HSS, and ceramics. It can be made of one material.

In addition, the fixed chuck 40 or the drill body 22 is preferably moved forward and backward repeatedly when forming the inner diameter, that is, the processing hole 12, in the magnesium alloy 10. At this time, the fixed chuck 40 Alternatively, the moving speed of the drill body 22 is characterized in that it is 10 to 100 mm/min, which is to smoothly discharge chips generated during cutting so that cutting can be performed smoothly, and the moving speed is 10 mm/min If it is less than this, the chip is not smoothly discharged, and irregularities may occur on the inner circumferential surface of the magnesium alloy 10, or a phenomenon in which the tip generated during cutting may stick to the inner circumferential surface of the magnesium alloy 10 may occur, and the moving speed is 100 mm / If min is exceeded, the chip can be discharged smoothly, but due to many repeated movements, the work time increases and the vibration transmitted to the magnesium alloy 10 according to the increase of the work time increases, resulting in damage or damage to the magnesium alloy 10. This is because variations may occur. At this time, the most preferable moving speed of the fixed chuck 40 may be 50 to 100 mm/min.

In the second cutting step (S20), it is preferable to use the fixed chuck 40 used in the first cutting step (S10) as it is, which is to minimize errors by preventing the position of the magnesium alloy 10 from changing , For this purpose, the fixing chuck 40 may be moved to the bite part 30 in which the bite 33 is installed, or the drill part 20 described above may be replaced with the bite part 30.

In addition, the cutting device used in the second cutting step (S20) is located at the front, fixes the front of the round bar-shaped magnesium alloy 10 at the rear, is movable forward and backward, and is rotatable. 40); and a bite portion 30 installed on one or the other rear side of the fixed chuck 40, and the bite portion 30 is movable forward and backward at the rear of the fixed chuck 40. It is characterized in that it is configured to include a base body 31; and, a tool arm 32 installed to be movable in the lateral direction to the base body 31 and to which a bite 33 is installed at the end At this time, the tool arm 32 is fixedly installed so as not to move in the lateral direction, and the base body 31 may be installed to be movable in the forward and backward and lateral directions.

In addition, the cutting device used in the second cutting step (S20) of the present invention corresponds to the processing hole 12 formed in the first cutting step (S10) and guide pin 34 inserted into the processing hole 12 It is characterized in that it is configured to include.

In more detail, the cutting device used in the second cutting step (S20) of the present invention includes a guide body 35 installed at the rear of the fixed chuck 40; and, the guide body 35 forward and backward. A guide body 36 movably installed; and a rotation guide 37 installed to be rotatable in front of the guide body 36 and having a guide pin 34 formed in a diameter corresponding to the processing hole 12 at the front. .

At this time, as the rotation guide 37 is rotatably installed in front of the guide body 36 by a bearing or the like, it is rotated at a speed corresponding to the rotational speed of the fixed chuck 40 so as to rotate the magnesium alloy 10. It will be apparent that the guide pin 34 inserted into the processing hole 12 can stably support the inside of the magnesium alloy 10.

That is, when turning the rear outer side of the magnesium alloy 10 with a bite 33, the guide pin 34 is inserted into the processing hole 12 to support the inner surface of the magnesium alloy 10, To ensure stable cutting.

In addition, it is advantageous for the guide pin 34 to have a diameter substantially identical to the diameter of the processing hole 12 so that turning by the bite 33 can be performed more stably. It is preferable that the diameter of the guide pin 34 is the same as that of the processing hole 12 or smaller than the diameter of the processing hole 12 by 0.01 mm or less.

In addition, when the guide pin 34 matches the diameter of the processing hole 12, it will be obvious that it is accurately inserted into the processing hole 12, and the air inside the processing hole 12 does not escape and the It is preferable to form the length of the processing hole 12 longer than the length of the tube to be manufactured, that is, the stent 100, in the first cutting step (S10) described above so that it can be compressed inside the processing hole 12. .

That is, in the second cutting step (S20) of the present invention, the fixed chuck 40 is rotated to rotate the magnesium alloy 10 and moved forward and backward, and the bite 33 is moved to one side or the other side to cut the magnesium alloy 10. In a state where the turning process or the fixed chuck 40 rotates the magnesium alloy 10, the bite 33 is moved forward and backward and one side or the other side to turn the magnesium alloy 10, and the bite ( 33) before the outside of the magnesium alloy 10 is turned, the guide pin 34 is inserted into the machining hole 12 of the magnesium alloy 10 so that the outside of the magnesium alloy 10 is stably turned. It will be.

In connection with the above, the second cutting step (S20) is a first outer diameter forming step (S22) of turning the rear outer side of the magnesium alloy 10 after the first cutting step (S10) with a bite 33; and, After the first outer diameter forming step (S22), the rear outer side of the magnesium alloy 10 is turned with a bite 33, but the cutting thickness is smaller than the first outer diameter forming step (S22). A second outer diameter forming step (S24) And turning the rear outer side of the magnesium alloy 10 after the second outer diameter forming step (S24) with a bite 33, but the cutting thickness is smaller than the second outer diameter forming step (S24). The third outer diameter forming step ( S26); And turning the rear outer side of the magnesium alloy 10 after the third outer diameter forming step (S26) with a bite 33, but the cutting thickness is smaller than the third outer diameter forming step (S26). Final outer diameter forming step (S28) It is composed of terms including.

The second cutting step (S20) of the present invention, like the first cutting step (S10) described above, does not form the outer diameter of the thin tube at once, but the first outer diameter forming step (S22) and the second outer diameter forming step (S24). ), through the third outer diameter forming step (S26) and the final outer diameter forming step (S28), the outer diameter of the thin tube, that is, the stent 100 to be finally manufactured, is more stable and precise by gradually cutting the smaller thickness can form

At this time, the final outer diameter forming step (S28) is characterized in that the rear outer side of the magnesium alloy 10 is turned with a cutting thickness of 0.01 to 0.1 mm, which is more precisely and stably in manufacturing the final thin tube. By cutting a very small thickness, it is to cut to manufacture a thin tube.

In addition, in the first outer diameter forming step (S22), the second outer diameter forming step (S24), the third outer diameter forming step (S26), and the final outer diameter forming step (S28), the rotational speed of the bite 33 is greater than 1500 rpm and less than 3600 rpm. It is preferable to do it at a speed of, which minimizes the temperature generated during cutting by cutting the magnesium alloy 10 at a higher speed and smoothes the outer circumference of the magnesium alloy 10, that is, the outer surface of the thin tube, that is, the stent 100 is to form

In addition, in the present invention, the outer circumferential surface of the thin tube to be manufactured, that is, the outer surface of the stent 100 to be manufactured is more smoothly and precisely processed, so that the second cutting step (S20) is compared to the first cutting step (S10). It proceeds through many steps, which is that the outer surface of the stent 100 is in close contact with the inner wall of the blood vessel, and the magnesium alloy using the guide pin 34 rather than forming the inner diameter of the magnesium alloy 10, that is, forming the processing hole 12 ( This is because the outer diameter of 10) can be formed, that is, the outside of the magnesium alloy 10 can be cut more stably.

In addition, the first outer diameter forming step (S22), the second outer diameter forming step (S24), the third outer diameter forming step (S26), and the final outer diameter forming step (S28) are cut by rotating the bite 33 at a very high speed. Therefore, the temperature during cutting is generated below about 50 degrees, so there is no need to use cutting oil, and thus, an effect of reducing unnecessary processes of removing cutting oil can be obtained.

In addition, the bite 33 is preferably made of a material that is harmless to the human body and the powder that can be worn during cutting. For example, any of cobalt, chrome, carbide, STS, nickel, SKD, SCM, HSS, ceramics It can be made of one material.

In addition, the fixed chuck 40 or the bite 33 is preferably repeatedly moved forward and backward when forming an outer diameter on the magnesium alloy 10, and at this time, the moving speed of the fixed chuck 40 or the bite 33 Is characterized in that 10 ~ 100mm / min, which is to ensure that the cutting is performed uniformly and at the same time to form a smooth surface, and when the moving speed is less than 10mm / min, a lot of vibration may occur during cutting, so that magnesium alloy ( 10) may have irregularities on the outer circumferential surface, and when the moving speed exceeds 100 mm/min, the outer circumferential surface of the magnesium alloy 10 may be formed smoothly, but damage or deformation of the magnesium alloy 10 due to many repeated movements may occur. because it can At this time, the most desirable moving speed of the bite 33 may be 50 to 100 mm/min.

At this time, in the second cutting step (S20), the central outer diameter of the stent 100 to be manufactured through the first outer diameter forming step (S22) to the final outer diameter forming step (S28) is formed to be about 0.02 to 0.07 mm thick , This is because the final decomposition rate is adjusted according to the thickness of the stent 100, so after the stent 100 is decomposed, the center of the affected area supported by the existing stent 100 is maintained in an expanded state for a longer period of time, In order to minimize the possibility of restenosis, when the outer diameter of the center of the stent 100 is formed thickly, it is preferable that the thickness of the stent 100 gradually decreases from the center in one or the other direction.

Next, the present invention includes a laser patterning step (S200) of manufacturing the stent 100 by forming a pattern by cutting the thin tube using a laser after the tube manufacturing step (S100).

In the laser patterning step (S200) of the present invention, the thin tube precisely manufactured in the tube manufacturing step (S100) is cut using a laser so that a pattern is formed, and the magnesium alloy 10 fixed to the fixed chuck 40 is formed. By cutting the front, that is, cutting, the stent 100 in the form of a net is manufactured.

At this time, since the laser patterning step (S200) of the present invention may use any conventional laser cutting technology, a detailed description thereof will be omitted.

On the other hand, the pattern according to the preferred embodiment formed in the laser patterning step (S200) is formed in the circumferential direction of one side of the thin tube, that is, the stent 100 to be manufactured, and the curved portion in the longitudinal direction of the stent 100 forward ( A first curved portion 111 from which 111a) protrudes, a first straight portion 112 extending from the first curved portion 111 and formed rearward in the longitudinal direction of the stent 100, and the first straight portion 1-1 curved portion 113 extending from 112, formed in one circumferential direction of the stent 100, and protruding backward in the longitudinal direction of the stent 100, and the 1-1 curved portion 113 ) Doedoe extending from, formed in the circumferential direction on one side of the stent 100, the first strut including the first and second curved portions 114 protruding forward in the longitudinal direction of the stent 100 zigzag in the circumferential direction The first cell 110 formed by being arranged;

It is formed in the circumferential direction of one side of the stent 100 to be manufactured, and the second curved portion 121 in which the curved portion 121a protrudes rearward in the longitudinal direction of the stent 100, and is formed extending from the second curved portion 121 , A second straight portion 122 formed in the longitudinal direction of the stent 100 and extending from the second straight portion 122, formed in the circumferential direction of one side of the stent 100, the stent 100 The 2-1 curved portion 123 in which the curved portion protrudes forward in the longitudinal direction of the 2-1 curved portion 123 and the 2-1 curved portion 123 are formed extending in the circumferential direction on one side of the stent 100, and the length of the stent 100 The second struts including the 2-2 curved portion 124 protruding in the rear direction are arranged in a zigzag pattern in the circumferential direction, and the second cell is connected adjacent to the front or rear of the first cell 110. (120).

In addition, the pattern according to the preferred embodiment is the first cell 110, the second cell 120, the first cell 110, the second cell 120 in the longitudinal direction of the stent 100 ... , and when the second cell 120 is adjacent to the rear of the first cell 110, the first and second curved portions 114 and the second cell 120 of the first cell 110 ) of the 2-2nd curved portion 124 is connected by a bridge 130, and when the rear of the second cell 120 is adjacent to the front of the first cell 110, of the first cell 110 The curved portion 111a of the first curved portion 111 and the curved portion 121a of the second curved portion 121 of the second cell 120 are integrally connected.

The pattern according to this preferred embodiment can be prevented from being easily broken by the curved parts when the stent 100 is bent, bent, or expanded in diameter, and in particular, when the stent 100 is expanded, smooth waves are not broken. It can be deformed into a shape and maintain a stable deformed state.

In addition, in the pattern according to the preferred embodiment, when the stent 100 is compressed, the bent parts are compressed and the straight parts are formed obliquely, so that the compressed state can be stably maintained.

The pattern in another embodiment formed in the laser patterning step (S200) is a thin tube, that is, a vertical line part 141 formed in the circumferential direction of one side of the stent 100 to be manufactured, and from the vertical line part 141 A first curved portion 142 that extends and is formed in one circumferential direction of the stent 100 and has a curved portion formed forward in the longitudinal direction of the stent 100, and is formed extending from the first curved portion 142, the stent A first horizontal straight portion 143 formed rearward in the longitudinal direction of (100) and an oblique straight portion 144 extending from the first horizontal straight portion 143 and formed in the circumferential direction of the other side of the stent 100 ) And the second horizontal straight portion 145 extending from the oblique straight portion 144, formed in the longitudinal direction of the stent 100, and extending from the second horizontal straight portion 145, the stent ( 100) and a strut including a second curved portion 146 extending in the circumferential direction on one side and having a curved portion formed rearward in the longitudinal direction of the stent 100, including a cell 140 made of zigzag arrangement in the circumferential direction It is composed by

In addition, the pattern according to another embodiment is formed by arranging the cells 140 in the longitudinal direction of the stent 100, and any one cell 140 and the cell 140 adjacent to the one cell 140 The vertical line portion 141 of any one cell 140 and the vertical line portion 141 of the cell 140 adjacent to the one cell 140 are connected by a bending bridge 150.

At this time, the bent bridge 150 is formed extending from the front straight portion 151 extending from the vertical line portion 141 of any one cell 140 and the front straight portion 151, stent 100 A first bent portion 152 in which a curved portion protrudes in one side of the circumferential direction of the first bent portion 152, and a second bent portion 153 extending from the first bent portion 152 and having a curved portion protruding in the other circumferential direction of the stent 100 ) and a rear straight portion 154 extending from the second bent portion 153 and connected to the vertical line portion 141 of the cell 140 adjacent to any one cell 140.

The pattern according to this other embodiment is prevented from being easily broken by the curved parts when the stent 100 is bent, bent, or expanded in diameter, and is bent more smoothly and stably through the bending bridge 150 It can be bent, and in particular, when the stent 100 is expanded, the stress is evenly distributed by the curved parts and the straight parts to prevent easy breakage.

In addition, in the pattern according to another embodiment, the bent parts and straight parts are formed in a balanced manner during compression and expansion of the stent 100, as well as the stability of being compressed or expanded more stably by the diagonal straight part 144. to be able to secure

Next, the present invention comprises the tube manufacturing step (S100) after the laser patterning step (S200) and the electrolytic polishing step (S300) of removing the tip or burr formed in the laser patterning step (S200).

The electropolishing step (S300) of the present invention is electropolishing, a polishing method using an electrochemical reaction, in which the material to be polished is used as an anode and the electrode is used as a cathode, and metal elution from the surface of the anode is used to convert the metal surface to a mirror surface. As a kind of polishing that makes it smooth, it is possible to effectively remove tips or burrs generated by manufacturing thin tubes and forming patterns by laser.

In addition, the electrolytic polishing step (S300) of the present invention forms a passivation film, which is a thin oxide film, on the surface of the stent 100 that has undergone the laser patterning step (S200), that is, on the surface of the magnesium alloy 10, greatly increasing corrosion resistance to magnesium The effect of improving the corrosion resistance and corrosion resistance of the alloy 10 is realized.

That is, the electrolytic polishing step (S300) of the present invention can effectively planarize the outer and inner surfaces of the stent 100 to be manufactured, and remove hydrogen that may exist in the magnesium alloy 10 to exhibit sterilization and cleaning effects. .

In addition, the electrolytic polishing step (S300) of the present invention removes the residual stress on the surface of the stent 100 manufactured through the tube manufacturing step (S100) and the laser patterning step (S200) to improve the inherent strength and texture of the magnesium alloy 10 to realize the effect of restoring

Next, the present invention comprises a coating step (S400) of forming a biodegradable coating layer on at least one of the surface of the stent 100, that is, the outer surface or the inner surface, after the electropolishing step (S300).

The biodegradable coating layer used in the coating step (S400) of the present invention is made of a biodegradable polymer, and the biodegradable polymer is a high molecular substance that is changed into a low molecular weight compound by being involved in the metabolism of organisms in at least one process of decomposition. In the meaning of, it is a generic term for polymers that are self-degradable in vivo or in the natural environment.

These biodegradable polymers include polyetherimide (PEI), poly-ε-caprolactone (PCL), chitosan, polylactic acid (PLA), polyglycolic acid acid; PGA), poly-ε-caprolactone-lactic acid copolymer (PCLA), poly-ε-caprolactone-glycolic acid copolymer (PCGA), polylactic acid-glycolic acid copolymer (PLGA), polyethylene glycol PEG), polydioxanone (PDO), poly(trimethylene carbonate) (PTMC), poly(amino acid), polyanhydride, polyorthoester (polyorthoester), polyphosphazene, polyiminocarbonate, polyphosphoester, polyhydroxyvalerate, copolymers thereof, and mixtures thereof.

The biodegradable coating layer may have flexibility by including the above-described polymer layer, and accordingly, when the stent 100 is bent or bent, it can be bent or bent together without falling off from the stent 100, which is biodegradable This means that the coating layer can maintain shape stability even after deformation of the flexible stent 100, and corrosion stability of the stent 100 is also maintained as the biodegradable coating layer maintains shape stability.

This biodegradable coating layer may be provided in a thickness of about 0.05 μm to about 10 μm. When the thickness of the biodegradable coating layer is less than about 0.05 μm, moisture and electrolyte ions may pass through the biodegradable coating layer and be easily transferred to the stent 100, and thus the corrosion resistance of the stent may be lowered, and the biodegradable coating layer If the thickness exceeds about 10 μm, the stent 100 may become unnecessarily thick or it may take a long time to decompose and remove the stent 100, and the flexibility of the biodegradable coating layer may decrease, causing the stent 100 to deteriorate. Since there is a concern that the biodegradable coating layer may be peeled off when strain is applied, it is preferable to provide the thickness as described above.

This biodegradable coating layer is formed on the stent 100 by a spray coating or spin coating method.

In addition, this biodegradable coating layer may contain a drug in the form of being supported on the inside, that is, a polymer layer, the drug may include an anti-proliferative agent, and the stent by the drug ( 100) is inserted into the affected area, it is possible to prevent overproliferation of affected smooth muscle cells in the affected area. It can act on the affected area to prevent restenosis.

In addition, the biodegradable coating layer of the present invention may be provided in a thickness of about 0.05 μm to about 8 μm in another embodiment, and to be positioned on top of the biodegradable coating layer in the center of the stent 100 to be manufactured. A second biodegradable coating layer further coated to a thickness of 2 μm may be further provided. At this time, it will be apparent that the second biodegradable coating layer is also included in the form of carrying the drug described above, and the second biodegradable coating layer is preferably coated so as to become thinner from the center of the stent 100 toward one side and the other side. .

The reason for providing the second biodegradable coating layer is to control the decomposition rate of the stent 100, and after the stent 100 is decomposed, the center of the affected area supported by the existing stent 100 is extended for a longer time to minimize the possibility of restenosis of the affected area. At this time, when the second biodegradable coating layer is provided, the thickness of the stent 100, that is, the outer diameter is constantly turned in the second cutting step (S20).

As a result, the manufacturing method of the stent for coronary artery containing biodegradable magnesium of the present invention and the stent manufactured by the manufacturing method are made of magnesium alloy 10 as a thin tube in that the material is an alloy containing magnesium as a main component. In order to do this, the cutting step was increased, the rotational speed and moving speed of the drill 24 and the bite 33 were adjusted for more precise cutting, and a guide jig was made to guide the drill 24 for more stable cutting. By using (25) and using the guide pin (34) when turning with the bite (33), it is possible not only to prevent a decrease in strength due to continuous micro-impact on the material during cutting, but also to improve formability to make the tube of the studded By manufacturing, the stent 100 in the form of a net can be easily manufactured by patterning using a laser, and the stent 100 can be manufactured more safely through the electrolytic polishing step (S300) and the coating step (S400). You can get it.

The above has been described with reference to preferred embodiments of the present invention, and the present invention is not limited to the above embodiments, and through the above embodiments, those skilled in the art to which the present invention belongs can understand the gist of the present invention. It can be implemented with various changes within a range that does not deviate.

10: magnesium alloy 12: processing hole
20: drill part 21: base frame
22: drill body 23: drill chuck
24: drill 25: guide jig
30: byte part 31: base body
32: tool arm 33: bite
34: guide pin 35: guide body
36: guide body 37: rotation guide
40: fixed chuck
100: stent 110: first cell
111, 142: first curved portion 111a, 121a: curved portion
112: first straight portion 113: first-first curved portion
114: 1st-2nd curved part 120: 2nd cell
121, 146: second curved portion 122: second straight portion
123: 2-1st curved part 124: 2-2nd curved part
130: bridge 140: cell
141: vertical line part 143: first horizontal straight part
144: oblique straight part 145: second horizontal straight part
150: bending bridge 151: front straight part
152: first bent portion 153: second bent portion
154: rear straight part

Claims (11)

A tube manufacturing step (S100) of manufacturing a magnesium alloy 10 in the form of a round bar into a thin tube; and
A laser patterning step (S200) of manufacturing a stent 100 by forming a pattern on a thin tube using a laser; and
an electrolytic polishing step (S300) of removing the tip or burr formed on the stent 100 in the tube manufacturing step (S100) and the laser patterning step (S200); and
A coating step (S400) of forming a biodegradable coating layer on the surface of the stent 100 after the electrolytic polishing step (S300);
The tube manufacturing step (S100)
A first cutting step (S10) of forming a processing hole 12 by cutting the rear inner side of the round bar-shaped magnesium alloy 10 with a drill 24; and
A second cutting step (S20) of turning the rear outer side of the magnesium alloy (10) after the first cutting step (S10) into a bite (33); Manufacturing method of arterial stent.
delete According to claim 1,
The first cutting step (S10) is
A first inner diameter forming step (S12) of forming a processing hole 12 by cutting the rear inner side of the magnesium alloy 10 with a first drill; and
A second inner diameter forming step (S14) of expanding the processing hole 12 by cutting the rear inner side of the magnesium alloy 10 with a second drill having a larger outer diameter than the first drill; A method of manufacturing a stent for coronary artery containing biodegradable magnesium.
According to claim 3,
The first cutting step (S10) is
A third inner diameter forming step (S16) of expanding the processing hole 12 by cutting the rear inner side of the magnesium alloy 10 with a third drill having a larger outer diameter than the second drill; A method of manufacturing a stent for coronary artery containing biodegradable magnesium.
According to claim 4,
The first cutting step (S10) is
A method of manufacturing a stent for coronary arteries containing biodegradable magnesium, characterized in that the difference in the outer diameters of the second drill and the third drill is smaller than the difference in the outer diameters of the first drill and the second drill.
According to claim 1,
The first cutting step (S10) is
A guide jig 25 having a guide hole corresponding to the outer diameter of the drill 24 is installed at the rear of the magnesium alloy 10, and the drill 24 passes through the guide hole of the guide jig 25. Method for manufacturing a stent for a coronary artery containing biodegradable magnesium, characterized in that being guided.
According to claim 1,
The second cutting step (S20)
A first outer diameter forming step (S22) of turning the rear outer side of the magnesium alloy 10 with a bite 33; and
A second outer diameter forming step (S24) of turning the rear outer side of the magnesium alloy 10 with a bite 33, the cutting thickness being smaller than the first outer diameter forming step (S22); and
A third outer diameter forming step (S26) of turning the rear outer side of the magnesium alloy 10 with a bite 33, the cutting thickness of which is smaller than that of the second outer diameter forming step (S24); and
Turning the rear outer side of the magnesium alloy 10 with a bite 33, the final outer diameter forming step (S28) having a cut thickness smaller than the third outer diameter forming step (S26); biodegradation characterized in that it is configured to include Method for manufacturing a stent for coronary arteries containing magnesium.
According to claim 7,
The final outer diameter forming step (S28)
Method for manufacturing a coronary stent containing biodegradable magnesium, characterized in that turning the rear outer side of the magnesium alloy (10) to a cutting thickness of 0.01 ~ 0.1mm.
According to claim 1,
The second cutting step (S20)
After inserting the guide pin 34 corresponding to the processing hole 12 formed in the first cutting step (S10) into the processing hole 12, turning the rear and outer sides of the magnesium alloy 10 with a bite 33 Method for manufacturing a stent for a coronary artery containing biodegradable magnesium, characterized in that to do.
According to claim 1,
The pattern formed in the laser patterning step (S200) is
It is formed in the circumferential direction of one side of the stent 100 to be manufactured, and the first curved portion 111 in which the curved portion 111a protrudes forward in the longitudinal direction of the stent 100, and is formed extending from the first curved portion 111. , A first straight portion 112 formed in the rear of the stent 100 in the longitudinal direction, and extending from the first straight portion 112, formed in the circumferential direction of one side of the stent 100, the stent 100 The 1-1 curved portion 113 in which the curved portion protrudes backward in the longitudinal direction of the 1-1 curved portion 113 and the 1-1 curved portion 113, formed in the circumferential direction of one side of the stent 100, the length of the stent 100 A first cell 110 in which first struts including first and second curved portions 114 protruding in a forward direction are arranged in a zigzag pattern in a circumferential direction; and
It is formed in the circumferential direction of one side of the stent 100 to be manufactured, and the second curved portion 121 in which the curved portion 121a protrudes rearward in the longitudinal direction of the stent 100, and is formed extending from the second curved portion 121 , A second straight portion 122 formed in the longitudinal direction of the stent 100 and extending from the second straight portion 122, formed in the circumferential direction of one side of the stent 100, the stent 100 The 2-1 curved portion 123 in which the curved portion protrudes forward in the longitudinal direction of the 2-1 curved portion 123 and the 2-1 curved portion 123 are formed extending in the circumferential direction on one side of the stent 100, and the length of the stent 100 The second struts including the 2-2 curved portion 124 protruding in the rear direction are arranged in a zigzag pattern in the circumferential direction, and the second cell is connected adjacent to the front or rear of the first cell 110. (120); Method for manufacturing a stent for a coronary artery containing biodegradable magnesium characterized in that it is configured to include.
A stent for a coronary artery containing biodegradable magnesium prepared according to any one of claims 1 and 3 to 10.

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