JP2004305768A - Medical device with surface having lubricity when it is humid - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a medical device which is composed of a polyolefine base material, and wherein a surface of the base material for the medical device is provided with a safe lubricating layer with lasting lubricity, preventing elimination, peeling and elution of a lubricative substance when it is humid. <P>SOLUTION: This medical device is characterized in that a bonding layer, which is composed mainly of a resin with adhesion to a polyolefine or modified polyolefine, and a surface lubricating layer, which is mainly composed of an insolubilized substance of a hydrophilic polymer wherein a reactive functional group is provided in a molecule and wherein the reactive functional groups react with each other so as to form an intermolecular crosslink, are formed on the outer surface of the single-layer or multilayer base material for the medical device, wherein a layer mainly composed of the polyolefine or the modified polyolefine is arranged at least on an outer layer. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a medical device having a lubricating layer that forms a hydrogel when wet on its outer surface. More specifically, the present invention relates to a catheter balloon and a dilatation catheter equipped with the catheter balloon.

  In recent years, dilatation catheters having a balloon at the distal end are frequently used as medical devices for dilating stenotic parts such as blood vessels and bronchi. Use a low-friction material for the catheter balloon or reduce the friction on the surface of the catheter balloon with the aim of improving the operability of accessing the catheter balloon to the target site and reducing tissue damage to the inner wall of blood vessels, etc. For this purpose, a method of coating a catheter balloon substrate with a lubricant, a low-friction resin, a hydrophilic polymer or the like has been studied.

  The method of applying fluororesin, silicone resin, silicone oil, olive oil, glycerin, etc. on the surface of the base material is a simple method, but it is difficult to remove the lubricating substance from the base material surface, such as delamination, peeling, and elution. There are many problems with the sustainability of the effects.

  In recent years, a method of producing a low-friction surface by coating a hydrophilic polymer and reacting to form a hydrogel on the surface has been studied. For example, Patent Literature 1 discloses a method in which a hydrophilic polymer (polyvinylpyrrolidone) is coated on a substrate surface using an isocyanate. Further, a method of coating a hydrophilic polymer obtained by copolymerizing a reactive functional group using isocyanate (Patent Document 2) and a method of coating polyethylene oxide (Patent Document 3) are disclosed. Patent Document 4 discloses that a copolymer such as a polyether, a polyamide, or a polysiloxane is provided via a polyisocyanate on a surface on which at least one of an amino group, an imino group, a carboxyl group, and a mercapto group is present. A method for binding is described. These surface lubrication methods require two types of compounds, an isocyanate compound and a hydrophilic polymer, to be uniformly coated, or a plurality of coating operations (for example, coating of a crosslinkable compound such as polyisocyanate and hydrophilicity). Polymer coating), which is not preferable in terms of operability. In addition, a compound having a plurality of reactive functional groups such as isocyanate groups in a molecule has high reactivity and easily reacts with moisture or impurities in the air, so that the management of steps and reagents is complicated. And it is harmful to the human body.

  Patent Document 5 discloses that a polymer having a reactive functional group (component A) is applied to a substrate surface, and then a hydrophilic polymer having a reactive functional group capable of reacting with the reactive functional group (component B) is coated. A method is described. However, this method has a good adhesion between the (A component) and the (B component) because the (B component) can be held on the substrate surface by the reaction between the (A component) and the (B component). However, the adhesion between (Component A) and the substrate becomes a problem. In particular, when a base material is a polyolefin such as polyethylene or polypropylene, the reaction product of the (A component) and the (B component) easily peels off when rubbed with a finger even if the peeling is not observed by boiling or the like. Often.

Also, like a catheter balloon, a molded article produced by stretching a polyolefin resin is difficult to perform surface treatment due to strong crystallinity and orientation, and it is difficult to form a strong hydrogelation surface lubricating layer. there were.

U.S. Pat. No. 4,100,309 JP-A-59-81341 JP-A-58-193766 1-55023 WO90 / 01344

  An object of the present invention is to provide a medical device, particularly a catheter balloon, comprising a polyolefin-based substrate having a lubricating layer on its surface that is safe and free of desorption, peeling, and elution of a lubricating substance when wet, and has a lubricating layer that maintains lubricity. Is to do.

The above object is achieved by the present invention having the following constitution.
(1) A resin having adhesiveness to the polyolefin or the modified polyolefin on the outer surface of a single-layer or multilayer medical device substrate in which a layer mainly composed of a polyolefin or a modified polyolefin is disposed at least as an outer layer. Medical treatment for forming a hydrogel layer on the outer surface when wet, characterized by forming a surface lubricating layer mainly composed of a mixture of a hydrophilic polymer having a reactive functional group in the molecule with a hydrophilic polymer Tools.
(2) A resin having adhesiveness to the polyolefin or the modified polyolefin on the outer surface of a single-layer or multilayer medical device substrate in which a layer mainly composed of a polyolefin or a modified polyolefin is disposed at least as an outer layer. And (b) a surface lubricating layer mainly composed of an insolubilized hydrophilic polymer having a reactive functional group in the molecule, which is bonded to the adhesive layer. A medical device which forms a hydrogel layer on the outer surface when wet.

In the present invention, the hydrophilic polymer having a reactive functional group refers to a hydrophilic polymer having an epoxy group, an acid chloride group, an aldehyde group, an isocyanate group, or the like as a reactive functional group in a molecule and water-soluble or absorbing 10% or more of water. It is a polymer compound that swells. The development of surface lubricity occurs when a hydrophilic polymer absorbs an aqueous solvent such as a physiological saline solution, a buffer solution, or blood. That is, it is considered that water existing on the surface of the material causes a lubrication function by fluid lubrication at the interface in contact with the blood vessel wall. Therefore, it is preferable that the hydrophilic polymer in the present invention has a water absorption of 100% by weight or more in a temperature range of use (usually 30 to 40 ° C.) in order to exhibit lubricity.

The method for producing a hydrophilic polymer having a reactive functional group can be obtained by copolymerizing a monomer having a reactive functional group in a molecule and a hydrophilic monomer. Preferably, it is a block copolymer or a graft copolymer in which monomers having a reactive functional group gather to form a reactive domain, and hydrophilic monomers gather to form a hydrophilic domain. . When it is a block copolymer or a graft copolymer, good results are obtained in the strength and lubricity of the surface lubricating layer.

Examples of the monomer having a reactive functional group include a monomer having a reactive heterocyclic ring such as glycidyl acrylate or glycidyl methacrylate in the molecule, and a monomer having an acid chloride such as acrylic acid chloride or methacrylic acid chloride in the molecule. And monomers having an isocyanate group in the molecule such as acryloyloxyethyl isocyanate. Preferred reactive monomers are glycidyl acrylate or glycidyl methacrylate in which the reactive group is an epoxy group, the reaction is accelerated by heat, and the handling is relatively easy. The reactive domain may be a domain composed of a copolymer of these reactive monomers and non-reactive monomers.

Examples of the hydrophilic monomer include acrylamide and derivatives thereof, vinylpyrrolidone, acrylic acid and methacrylic acid, and polymers of these derivatives and water-soluble monomers as main components. For example, N-methylacrylamide, N, N-dimethylacrylamide, acrylamide, acryloylmorpholine, N, N-dimethylaminoethyl acrylate, vinylpyrrolidone, 2-methacryloyloxyethylphosphorylcholine, 2-methacryloyloxyethyl-D-glycoside , 2-methacryloyloxyethyl-D-mannoside, vinyl methyl ether and the like can be preferably exemplified, but not limited thereto.

The hydrophilic polymer having a reactive functional group is preferably a polymer having in its molecule an epoxy group whose reaction is easily promoted by heat. After coating the medical device base material with the hydrophilic polymer having a reactive functional group, the surface lubricating layer can be easily formed by insolubilizing by performing a heat treatment at 40 ° C. or higher. The heat treatment promotes the reaction between the hydrophilic polymers and the reaction with the medical device substrate when the surface of the medical device substrate has a functional group capable of reacting with the hydrophilic polymer. The temperature is preferably at least 50 ° C, more preferably at least 60 ° C. To promote the reaction, a catalyst may be added in addition to heat. For example, a tertiary amine compound such as a trialkylamine compound or pyridine is preferably used for an epoxy group. Light, an electron beam, radiation, or the like may be used to promote a reaction other than heat.

Further, a hydrophilic polymer having a reactive functional group, a hydrophilic polymer that reacts with the reactive functional group, for example, when the reactive functional group is an epoxy group, a carboxyl group that reacts with the epoxy group, a hydroxyl group, A hydrophilic polymer containing a monomer having an amino group, a carboxylic anhydride, a thiol group or the like as a constituent may be added and reacted to form an insolubilized surface lubricating layer.

The modified polyolefin is a copolymer (random copolymer, block copolymer, graft copolymer) of an olefin such as ethylene or propylene with another monomer, or a polymer alloy containing an olefin as a main component. Examples of monomers to be copolymerized include maleic anhydride, acrylic acid and derivatives thereof, methacrylic acid and derivatives thereof, vinyloxysilane, ketene acetal, dioxolan, and vinyl acetate.

The polymer having an adhesive property to the polyolefin may be a polymer that is commercially available as an adhesive polymer to the polyolefin, or a polymer synthesized to improve the compatibility with the polyolefin and the adhesive property. For example, a copolymer of a polyolefin and maleic anhydride, ethyl acrylate, acrylic acid, methacrylic acid, glycidyl methacrylate, or the like will exhibit good adhesiveness.

Examples of the adhesive polymer for the modified polyolefin include the above-mentioned modified polyolefins including the modified polyolefin having the same structure as the base material.

The surface lubricating layer coated on the outer surface of the medical device is made of a hydrophilic polymer having a reactive functional group. On the outer surface of the medical device, the reactive functional groups in the hydrophilic polymer react with each other due to heat or the like. And form intermolecular crosslinks. The crosslinked hydrophilic polymer absorbs water and swells when it comes into contact with body fluids or physiological saline, forming a hydrogel layer having lubricity.

When the modified polyolefin forming the medical device base or the adhesive polymer forming the adhesive layer has a functional group capable of reacting with the hydrophilic polymer forming the surface lubricating layer, the modified polymer is modified with the hydrophilic polymer. Reacts with polyolefin and adhesive polymer to form a strong surface lubrication layer. Furthermore, even when the medical device base material is a polyolefin having no functional group capable of reacting with the hydrophilic polymer, the hydrophilic polymer is mainly used because the adhesive layer has an adhesive polymer having an adhesive property with the polyolefin. The peel resistance of the surface lubricating layer as a component is improved.

The adhesive layer may be formed by coextruding or coating the adhesive polymer in advance on the medical device substrate, or by dissolving the adhesive polymer in a solvent together with the hydrophilic polymer and applying it to the medical device substrate. You may. Further, in order to increase the peel resistance of the adhesive polymer to the medical device substrate, it is desirable to dissolve the adhesive polymer in a solvent in which the substrate swells and coat the substrate. Examples of such a solvent include toluene, xylene, benzene, tetrahydrofuran, dioxane, hexane, and methylene chloride, and a mixed solvent based on them. The solvent is selected according to the properties of the base material, and the coating conditions are set.

In particular, when the medical device is a dilatation catheter balloon, the surface lubrication layer does not need to be formed on the entire balloon, but may be formed partially on the tapered portion on the distal side or the base side of the balloon. In particular, when the blood vessel is dilated, it is preferable not to treat the entire balloon in consideration of holding at the target site. On the other hand, when a drug (an antithrombotic drug) is administered for the purpose of suppressing restenosis of the dilated blood vessel, it is better to perform the entire treatment.

The catheter balloon substrate only needs to have an olefin or modified polyolefin layer on its surface, and may be a multilayer balloon or a metal-containing balloon. In the case of multi-layering, examples include multi-layering with polyester, polyamide, polyphenylene sulphite, polyether sulfone, polyimide, etc. in order to improve the pressure resistance and reduce the deformation due to pressure (non-compliant type). it can.

A typical example of a method for manufacturing a catheter balloon will be described below.
(1) A catheter balloon having a surface layer mainly composed of polyolefin or modified polyolefin was formed.
(2) A solution containing at least a resin having adhesiveness to the polyolefin or the modified polyolefin and a hydrophilic polymer having a reactive functional group in the molecule was applied to the substrate using the balloon as a substrate. .
(3) The hydrophilic polymer was reacted by heat or the like to produce a surface-lubricated polyolefin catheter balloon having a lubricating layer on the substrate surface.

Further, as another manufacturing method, (1) a catheter balloon having a surface layer mainly composed of polyolefin or modified polyolefin was formed.
(2) Using the balloon as a substrate, a solution containing at least a resin having adhesive properties to the polyolefin or the modified polyolefin was applied to the substrate.
(3) A solution containing at least a hydrophilic polymer having a reactive functional group in the molecule was applied.
(4) The hydrophilic polymer was reacted by heat or the like to produce a surface-lubricated polyolefin catheter balloon having a lubricating layer on the substrate surface.

Further, it is also possible to perform the above-mentioned application step a plurality of times in order to strengthen the lubricating layer and improve the function.

Particularly preferred examples of the medical device of the present invention include catheters and guidewires used in blood vessels, and other examples of the medical devices described below.
1) Catheters, such as gastric tube catheters, feeding catheters, and tubes for tube feeding (ED), which are inserted or placed in the digestive tract orally or nasally.
2) Oxygen catheter, oxygen cannula, endotracheal tube tube and cuff, tracheostomy tube tube and cuff, intratracheal suction catheter such as orally or nasally inserted or placed in the airway or trachea 3) Urethra Catheters inserted or placed in the urethra or ureter such as catheters, urinary catheters, balloon catheters and balloons 4) Inserted or placed in various body cavities, organs, tissues such as suction catheters, drainage catheters, and rectal catheters Catheters.
5) Indwelling needles, IVH catheters, thermodilution catheters, angiographic catheters, vascular dilatation catheters, and catheters inserted or indwelled in blood vessels such as dilators or introducers. Alternatively, guidewires, stylets, etc. for these catheters.
6) Examination instruments and treatment instruments for inserting various organs, contact lenses, etc. 7) Stents, artificial blood vessels, artificial trachea, artificial bronchi, etc.
8) Medical devices (artificial heart, artificial lung, artificial kidney, etc.) for extracorporeal circulation treatment and their circuits.

  The catheter balloon of the present invention is a material in which a mixture of an adhesive polymer and a hydrophilic polymer insolubilized substance is bonded to a substrate surface made of a polyolefin or a modified polyolefin, or is hydrophilic on the substrate surface via the adhesive polymer. Since the material is a material to which an insolubilized hydrophilic polymer is bonded, the surface lubricating layer made of a hydrophilic polymer has superior peel resistance compared to a material having a hydrophilic polymer bonded directly to the substrate surface. . Further, since the catheter balloon of the present invention has a lubricating surface, it is excellent in reachability to a target site and low invasiveness to a living tissue (such as an inner wall of a blood vessel). Further, since the surface lubricating layer which forms a hydrogel when wet has a function as a drug reservoir, it is also useful as a balloon catheter for drug administration.

Hereinafter, the present invention will be described specifically with reference to examples.
(Example 1)
<Preparation of catheter balloon substrate> A modified polyolefin (acrylic acid-modified polyethylene A221M, manufactured by Mitsubishi Yuka Co., Ltd.) is molded into a tube having an outer diameter of 1.1 mm and an inner diameter of 0.7 mm, and then is biaxially stretched and oriented. A balloon as shown in FIG. That is, after the tube is pulled and stretched in the tube axis direction, the inside of the tube is pressurized and expanded in the tube radial direction by using a mold having a concave portion (cavity) in an expanded state of the balloon, whereby the balloon ( (Outer diameter: 3 mm).

<Synthesis of block polymer (hydrophilic polymer)> Obtained by dropping 29.7 g of triethylene glycol at 50 ° C in 72.3 g of adipic dichloride, and then removing hydrochloric acid under reduced pressure at 50 ° C for 3 hours. 4.5 g of methyl ethyl ketone was added to 22.5 g of the oligoester, added dropwise to a solution consisting of 5 g of sodium hydroxide, 6.93 g of 31% hydrogen peroxide, 0.44 g of surfactant dioctyl phosphate, and 120 g of water. The reaction was performed for 20 minutes. The obtained product was repeatedly washed with water and methanol, and then dried to obtain a polyperoxide having a plurality of peroxide groups in the molecule (PPO). Subsequently, 0.5 g of this PPO as a polymerization initiator and 9.5 g of glycidyl methacrylate (GMA) were polymerized in 30 g of benzene as a solvent at 80 ° C. for 2 hours while stirring under reduced pressure. The reaction product was reprecipitated with diethyl ether to obtain polyGMA having a peroxide group in the molecule. Subsequently, 1 g of the polyGMA was used as a polymerization initiator, 8 g of dimethylacrylamide (DMAA) was charged as a hydrophilic monomer in DMSO, and polymerized at 80 ° C. for 18 hours to obtain polyGMA as a reactive domain and a water-swellable hydrophilic polymer. A block copolymer of dimethylacrylamide-glycidyl methacrylate (molar ratio 6: 1) was synthesized as a block copolymer (hydrophilic polymer) having poly-DMAA as a functional domain.

<Preparation of Surface Lubricated Catheter Balloon> The prepared balloon substrate was made of a modified polyolefin, ethylene-acrylate-maleic anhydride terpolymer (Bondane AX-8390, manufactured by Sumika CDF Chemical Company). %, 2% of a block polymer, and 1% of pyridine as a catalyst in a chloroform / toluene (weight ratio: 1: 1) solution for 1 minute, and then dried in an oven at 60 ° C. for 18 hours.

<Surface Lubricity Evaluation Test Method> The following two indices were adopted as the surface lubricity of the catheter balloon. That is, the frictional resistance value as an index of operability of a catheter balloon at a vascular stenosis part (target site), the pull-out resistance value as an index of retention of the catheter balloon at a vascular stenosis part (target site), and the surface lubricity The change in frictional resistance value (△ frictional resistance value) was adopted as an index of the sustainability of the tire.
(1) Friction resistance As shown in FIG. 2, 30 parts by weight of polypropylene (Hypol F401, manufactured by Mitsui Petrochemical Industries, Ltd.) and 70 parts by weight of polybutene (Bureon, manufactured by Mitsui Petrochemical Industries, Ltd.) were biaxially kneaded to obtain an inner diameter of 0%. A shaft 2 having a diameter of .85 mm and an outer diameter of 1.00 mm was prepared, and a catheter 3 in which the balloon 1 prepared in the example was adhered to the tip of the shaft was prepared. Next, as shown in FIG. 3, a winding portion (one and a half turns with an inner diameter of 30 mm) is formed with a polyethylene pipe 7 having an inner diameter of 3 mm and an outer diameter of 5 mm, and water is filled in the pipe 7, and a vascular system in a living body is formed. After imitating the flow path 5, the catheter 3 with the balloon 1 folded was inserted into the flow path 5, and the balloon 1 was set so that the distal end of the balloon 1 was positioned at the end of the winding part. The end of the shaft 2 was set on the load cell 6 of Autograph AGS-100A manufactured by Shimadzu Corporation, and the resistance value when the balloon 1 was reciprocated within a stroke length of 10 mm was measured. The resistance immediately after the termination was adopted as the frictional resistance (gf). The results are shown in Table 1.
(Measurement condition)
・ Load cell 5kgf
・ Stroke length 10mm
・ Stroke speed 100mm / min
-Number of strokes 100 times (2) Pull-out resistance As shown in Fig. 4, the flow path 8 was composed of a polyethylene pipe 9 having an inner diameter of 3mm and an outer diameter of 5mm immersed in water, and the catheter 3 was folded in the same manner as described above with the balloon folded. The balloon was inserted into the channel 8, and then pressure was applied to the balloon, and the balloon was held in the channel 8 in an inflated state. The end of the shaft 2 was set on a load cell (not shown) of Autograph AGS-100A manufactured by Shimadzu Corporation, and the pull-out resistance value (gf) was measured, and the highest resistance value at the time of pull-out was adopted. The results are shown in Table 1.
(Measurement condition)
・ Load cell 5kgf
・ Cross head speed 10mm / min
・ Balloon pressure 8kg / cm ²
(3) Friction resistance value Friction resistance value was calculated by the following equation (A), and the results are shown in Table 1.
ΔFriction resistance = (final friction resistance)-(initial friction resistance) (A)

  (Example 2) A balloon treated in the same manner as in Example 1 was further immersed in a tetrahydrofuran solution containing 2% of a block polymer and 1% of pyridine as a catalyst for 1 minute, and then dried in an oven at 60 ° C for 18 hours. I let it. The produced balloon was evaluated in the same manner as in Example 1, and the results are shown in Table 1.

  (Example 3) The balloon substrate prepared in Example 1 was added to a 2% toluene / dimethylformamide (4: 1 weight ratio) solution of the modified polyolefin (bondine AX-8390) used in Example 1 at 50 ° C. After soaking for 2 minutes, it was dried in an oven at 60 ° C. for 1 hour. Subsequently, the resultant was immersed in a tetrahydrofuran solution containing 2% of the block polymer synthesized in Example 1 and 1% of pyridine as a catalyst for 1 minute, and then dried in a 60 ° C. oven for 18 hours. The produced balloon was evaluated in the same manner as in Example 1, and the results are shown in Table 1.

  (Comparative Example 1) The balloon base material produced in Example 1 was evaluated in the same manner as in Example 1 without performing a surface treatment, and the results are shown in Table 1.

  (Example 4) A tube made of linear low-density polyethylene (ZF260-1, manufactured by Tosoh Corporation) was formed into a balloon in the same manner as in Example 1, and then subjected to electron beam crosslinking (500 kv, 30 Mrad). . The prepared balloon substrate was chloroform / toluene containing 1% of the modified polyolefin (bondyne AX-8390) used in Example 1, 2% of the block polymer synthesized in Example 1, and 1% of pyridine as a catalyst (weight ratio). 1: 1) After being immersed in the solution for 1 minute, it was dried in a 60 ° C. oven for 18 hours. The produced balloon was evaluated in the same manner as in Example 1, and the results are shown in Table 1.

  (Example 5) The balloon base material prepared in Example 4 was immersed in a 2% toluene / dimethylformamide (weight ratio: 4: 1) solution of the same modified polyolefin as in Example 1 at 50 ° C for 2 minutes. It was dried in a 60 ° C. oven for 1 hour. Subsequently, the resultant was immersed in a tetrahydrofuran solution containing 2% of the same block polymer as in Example 1 and 1% of pyridine as a catalyst for 1 minute, and then dried in a 60 ° C. oven for 18 hours. The produced balloon was evaluated in the same manner as in Example 1, and the results are shown in Table 1.

  (Comparative Example 2) The balloon base material prepared in Example 4 was added to a toluene / dimethylformamide (4: 1) solution containing 2% of the same block polymer as in Example 1 and 1% of pyridine as a catalyst at 50 ° C. After soaking for 2 minutes, it was dried in an oven at 60 ° C. for 18 hours. The produced balloon was evaluated in the same manner as in Example 1, and the results are shown in Table 1.

  Comparative Example 3 The balloon used as a substrate in Example 4 was evaluated in the same manner as in Example 1 without performing a surface treatment, and the results are shown in Table 1.

The front view and side view explaining the shape of the catheter balloon of one Example of this invention. BRIEF DESCRIPTION OF THE DRAWINGS The front view explaining the shape of the catheter which adhered the catheter balloon of one Example of this invention to the shaft front-end | tip. FIG. 4 is an explanatory view showing one test method for evaluating the surface lubricity of the present invention. FIG. 4 is an explanatory diagram showing another test method for evaluating surface lubricity according to the present invention.

Explanation of reference numerals

DESCRIPTION OF SYMBOLS 1 Catheter balloon 2 Shaft 3 Catheter 4 Adhesion site 5, 8 Channel 6 Autograph load cell 7, 9 Polyethylene pipe

Claims (6)

  An adhesive layer mainly composed of a resin having an adhesive property to the polyolefin or the modified polyolefin, on an outer surface of a single-layer or multilayer medical device substrate in which a layer mainly composed of a polyolefin or a modified polyolefin is arranged at least as an outer layer; Medical treatment characterized by forming a surface lubricating layer mainly composed of a hydrophilic polymer having a reactive functional group in a molecule and reacting with each other to form an intermolecular crosslink. Tools.   The adhesive resin is characterized by comprising a copolymer of olefin and maleic anhydride, ethyl acrylate, acrylic acid, methacrylic acid, glycidyl methacrylate, vinyloxysilane, ketene acetal, dioxolan, vinyl acetate. The medical device according to claim 1, wherein   The medical device according to claim 1, wherein the reactive functional group is any one of an epoxy group, an acid chloride group, an aldehyde group, and an isocyanate group.   The medical device according to claim 1, wherein the hydrophilic polymer is obtained by copolymerizing a monomer having a reactive functional group in the molecule and a hydrophilic monomer.   The medical device according to claim 1, wherein the medical device is a catheter or a guidewire. The medical device according to claim 1, wherein the medical device is a catheter balloon.

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