阅读说明：本技术 导尿管及其制备方法 (Catheter and preparation method thereof ) 是由 李业 雷杰华 于 2019-02-22 设计创作，主要内容包括：本发明涉及一种导尿管及其制备方法,本发明的导尿管包括：管体、形成于所述管体表面的涂层、以及层层自组装于所述涂层外表面的肝素和壳聚糖,所述涂层由涂层组合物形成,所述涂层组合物包括至少一种可光固化聚合物。本发明的导尿管能够避免导尿管对于尿道内表面的损伤。同时,能够有效抑制结晶的堆积并杀死粘附在导尿管表面以及尿道创面上的细菌,减小细菌感染的风险。(The invention relates to a catheter and a preparation method thereof, and the catheter comprises: the coating comprises a pipe body, a coating formed on the surface of the pipe body, and heparin and chitosan which are self-assembled on the outer surface of the coating layer by layer, wherein the coating is formed by a coating composition, and the coating composition comprises at least one photo-curable polymer. The catheter can avoid the damage of the catheter to the inner surface of the urethra. Meanwhile, the accumulation of crystals can be effectively inhibited, bacteria adhered to the surface of the catheter and the wound surface of the urethra can be killed, and the risk of bacterial infection is reduced.)

1. A urinary catheter, comprising: the coating comprises a pipe body, a coating formed on the surface of the pipe body, and heparin and chitosan which are self-assembled on the outer surface of the coating layer by layer, wherein the coating is formed by a coating composition, the coating composition comprises at least one photocurable polymer, wherein,

the photocurable polymer is polymerized by components comprising water-soluble photosensitive monomers and hydrophilic monomers,

the water-soluble photosensitive monomer contains: 1) a unit containing a photosensitive structure; 2) a unit containing a quaternary ammonium salt structure; 3) a unit containing an unsaturated bond structure;

the unit containing the photosensitive structure is connected with the unit containing the quaternary ammonium salt structure through at least-C (═ O) -, and the unit containing the unsaturated bond structure is connected with the unit containing the photosensitive structure through the unit containing the quaternary ammonium salt structure.

2. The urinary catheter according to claim 1, wherein the water-soluble photosensitive monomer has the structure of formula (I):

wherein: r₁＝CH₃Or H; r₂And R₃Each independently selected from a straight chain alkyl group of 1 to 20 carbon atoms or a branched alkyl group of 3 to 20 carbon atoms; x is halogen; n is 1-10; m is 1-4; f is 1-3.

3. The catheter according to claim 1 or 2, wherein the hydrophilic monomer comprises one or more of an unsaturated carboxylic acid, an unsaturated carboxylic acid salt, an unsaturated carboxylic acid ester, an unsaturated acid hydroxyalkyl ester, an unsaturated acid anhydride, an unsaturated amide, an unsaturated lactam, and an alkylene oxide.

4. A catheter according to any of claims 1 to 3 wherein the water-soluble photosensitive monomer is present in an amount of 0.01% to 20% by weight based on the total mass of the hydrophilic monomer.

5. A catheter according to any of claims 1 to 4 wherein the number average molecular weight of the photocurable polymer is in the range of 5 to 70 ten thousand.

6. A catheter according to any of claims 1-5 wherein the thickness of the coating is 1-20 μm.

7. A catheter according to any of claims 1-6 wherein said layer-by-layer self-assembly means that heparin and chitosan are alternately formed on the outer surface of said coating.

8. A method for preparing a urinary catheter according to any one of claims 1 to 7, comprising:

(i) forming the coating composition on the surface of the catheter body, and curing under the condition of illumination;

(ii) and (2) alternately self-assembling the heparin and the chitosan on the outer surface of the coating to form a heparin and chitosan double molecular layer, and repeating the alternate self-assembly for n times to form n layers of heparin and chitosan double molecular layers, wherein n is more than or equal to 1.

9. The method according to claim 8, wherein the light source used for the illumination is any one of a UV light source, a visible light source, and an infrared light source.

10. The production method according to claim 8 or 9, wherein the light source is a UV light source, and the intensity of UV light at the time of curing is 5 to 25mW/cm²And the curing time is 2-7 minutes.

Technical Field

The invention belongs to the field of medical instruments, and particularly relates to the field of catheters with modified surfaces.

Background

The indwelling catheterization method is a method of draining urine by keeping a catheter in a bladder after catheterization, is widely applied to seriously ill patients after anesthesia or surgery, and is a clinical and common invasive nursing operation. Catheters used in the indwelling catheterisation method have higher performance requirements than catheters used for a short period of time. The main reason is that the indwelling catheter is prone to cause various complications in vivo, such as catheter-associated urinary tract infection, bladder function impairment, formation of crystals on the surface of the catheter, and the like.

The most typical problem of the indwelling catheter is urinary tract infection, the insertion of the catheter often causes damage to urethral mucosa, destroys the natural barrier of the urethral mucosa and weakens the defense effect of the urethral mucosa on bacteria; meanwhile, the urinary catheter is used as a foreign body, so that the normal scouring effect of the bladder on bacteria is influenced, and the probability of bacterial infection is greatly improved. According to survey data, the infection rate of the catheter used for a single short time is 1-5%, the infection rate of the indwelling catheter is 9.9%, the infection rate can rise linearly with the increase of the retention days of the indwelling catheter, urinary tract infection caused by the indwelling catheter accounts for about 40% of all infection in a hospital, and the urinary tract infection is a very common infection problem.

The infectious bacteria of the indwelling catheter are the same as the pathogenic bacteria of general urinary tract infection, common escherichia coli, klebsiella, proteus, enterococcus, serratia, candida and the like are provided, clinical practice generally uses iodophor to scrub the urethral orifice for disinfection or locally sprays antibiotics for prevention and treatment, but the iodophor is used for a long time to cause great damage to skin mucous membrane, the surface is easy to form hard scab, the use of the antibiotics can influence the medication condition of patients and cause trouble to the normal diagnosis of doctors, and in addition, the long-term use of the antibiotics can easily cause the formation of drug-resistant bacteria, so that the use of the antibiotics is not recommended.

In addition, the formation of crystals on the surface of the indwelling catheter is the second major problem of the indwelling catheter, on one hand, the crystals on the surface of the indwelling catheter are easy to cause bacterial growth to cause urinary tract infection, and on the other hand, the urethral mucosa is easily damaged during tube drawing. Although surface crystallization is a partial cause of urinary tract infection, most indwelling catheter designs and clinical treatments focus on the prevention and treatment of bacterial infection as described above, and do not consider the formation of surface crystallization on catheters.

Patent document 1 discloses a urinary catheter capable of preventing urinary tract infection. The invention utilizes hydrogel to coat and coat antibiotics such as kanamycin, ampicillin, cefradine, roxithromycin, ofloxacin and the like on the surface of the catheter, and utilizes the slow-release antibiotics to treat infection. However, long-term use of antibiotics is easy to generate drug-resistant bacteria, so that the antibacterial effect is not effective, and side effects are easy to generate on patients, so that the long-term use of antibiotics is not an optimal mode for resisting infection for a long time.

Patent document 2 discloses an infection-preventing urinary catheter. The invention utilizes the ultraviolet lamp strip arranged in the catheter to sterilize the urethra, thereby reducing the infection probability. However, this method of sterilization by ultraviolet irradiation is also prone to unknown damage to the beneficial cells on the urethral surface, resulting in greater damage.

Patent document 1: CN109107021A

Patent document 2: CN108379720A

Disclosure of Invention

Problems to be solved by the invention

In order to solve the defects and shortcomings of the prior art, the invention provides the catheter and the preparation method thereof, which can avoid the injury of the catheter to the inner surface of the urethra. Meanwhile, the accumulation of crystals can be effectively inhibited, bacteria adhered to the surface of the catheter and the wound surface of the urethra can be killed, and the risk of bacterial infection is reduced.

Means for solving the problems

The inventor of the invention finds that the technical problems can be solved by the following technical scheme:

[1] the invention provides, in a first aspect, a urinary catheter comprising: the coating comprises a pipe body, a coating formed on the surface of the pipe body, and heparin and chitosan which are self-assembled on the outer surface of the coating layer by layer, wherein the coating is formed by a coating composition, the coating composition comprises at least one photocurable polymer, wherein,

the photocurable polymer is polymerized by components comprising water-soluble photosensitive monomers and hydrophilic monomers,

the water-soluble photosensitive monomer contains: 1) a unit containing a photosensitive structure; 2) a unit containing a quaternary ammonium salt structure; 3) a unit containing an unsaturated bond structure;

the unit containing the photosensitive structure is connected with the unit containing the quaternary ammonium salt structure through at least-C (═ O) -, and the unit containing the unsaturated bond structure is connected with the unit containing the photosensitive structure through the unit containing the quaternary ammonium salt structure.

[2] The urinary catheter according to [1], wherein the water-soluble photosensitive monomer has a structure of the formula (I):

wherein: r₁＝CH₃Or H; r₂And R₃Each independently selected from a straight chain alkyl group of 1 to 20 carbon atoms or a branched alkyl group of 3 to 20 carbon atoms; x is halogen; n is 1-10; m is 1-4; f is 1-3.

[3] The catheter according to [1] or [2], wherein the hydrophilic monomer comprises one or more of an unsaturated carboxylic acid, an unsaturated carboxylic acid salt, an unsaturated carboxylic acid ester, an unsaturated acid hydroxyalkyl ester, an unsaturated acid anhydride, an unsaturated amide, an unsaturated lactam, and an alkylene oxide.

[4] The catheter according to any one of [1] to [3], wherein the water-soluble photosensitive monomer is contained in an amount of 0.01 to 20 wt% based on the total mass of the hydrophilic monomer.

[5] The catheter according to any one of [1] to [4], wherein the photocurable polymer has a number average molecular weight of 5 to 70 ten thousand.

[6] The urinary catheter according to any one of [1] to [5], wherein the coating layer has a thickness of 1 to 20 μm.

[7] The urinary catheter according to any one of [1] to [6], wherein the layer-by-layer self-assembly means that heparin and chitosan are alternately formed on the outer surface of the coating layer.

[8] A method for producing a urinary catheter according to any one of [1] to [7], comprising:

(i) forming the coating composition on the surface of the catheter body, and curing under the condition of illumination;

(ii) and (2) alternately self-assembling the heparin and the chitosan on the outer surface of the coating to form a heparin and chitosan double molecular layer, and repeating the alternate self-assembly for n times to form n layers of heparin and chitosan double molecular layers, wherein n is more than or equal to 1.

[9] The production method according to item [8], wherein the light source used for the illumination is any one of a UV light source, a visible light source, and an infrared light source.

[10]According to [8]]Or [9]]The preparation method is characterized in that the light source is a UV light source, and the intensity of ultraviolet light during curing is 5-25mW/cm²And the curing time is 2-7 minutes.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the invention, the lubricating coating is formed on the surface of the catheter, so that the friction force between the catheter and the urethra in the insertion or extraction process is reduced, and the damage of the catheter to the inner surface of the urethra is avoided. Meanwhile, the quaternary ammonium salt with positive charges on the surface of the lubricating coating is further used for carrying out layer-by-layer self-assembly on the quaternary ammonium salt, heparin and chitosan are modified on the surface, and the operation is convenient and simple.

Wherein, the property that heparin can form a covering protective layer on the surface of the urethral wound and the catheter is utilized to effectively inhibit the accumulation of crystals. The bacteria adhered to the surface of the catheter and the wound surface of the urethra are killed by utilizing the bactericidal performance of chitosan, and the risk of bacterial infection is reduced.

Drawings

FIG. 1 is a graph showing the results of the antibacterial test in example 1 and comparative example 1

Wherein the left side is the test result of comparative example 1 and the right side is the test result of example 1.

Detailed Description

The technical solution of the present invention will be described in detail with reference to the following examples.

The term "monomer" in the present invention means any chemical species that can be characterized by a chemical formula with polymerizable groups (including (meth) acrylate groups) that can be polymerized into oligomers or polymers to increase molecular weight. The molecular weight of the monomers can generally be calculated simply from the given formulae.

Hereinafter, when a moiety of a molecule is described as "optionally substituted" or "substituted", this means that the moiety may be substituted with one or more substituents selected from the group consisting of: C1-C6 linear, branched or cyclic alkyl, aryl, -OH, -CN, halogen, amine, amide, alcohol, ether, thioether, sulfone and its derivatives, sulfoxide and its derivatives, carbonate, isocyanate, nitrate and acrylate.

The term "unit" in the present invention means not only a functional group (e.g., photosensitive group, quaternary ammonium salt group, unsaturated group) but also an additional chemical group having a small influence on the functional group, such as alkyl group, alkylene group, etc.

The term "polymer" in the present invention refers to a molecule containing two or more repeating units, in particular, a polymer may be formed from two or more monomers, which may be the same or different, and when used in the present invention, the term also includes oligomers or prepolymers. The term "molecular weight" in the present invention means the number average molecular weight (M)_n)，M_nDefined as M determined by light scattering, optionally in combination with Size Exclusion Chromatography (SEC)_n。

The term "curing" is understood in the present invention as: physical or chemical hardening or solidification, or curing by chemical reaction, such as radiation curing, thermal curing or curing with the addition of curing molecules, initiators, by any method such as heating, cooling, drying, crystallization.

The term "photocuring" can be achieved in the present invention in the following exemplary manner: the photoinitiation process occurs via irradiation with light or UV radiation in the wavelength range from 100nm to 600 nm. Illumination sources that may be used are sunlight or artificial lamps or lasers. For example, high, medium or low pressure mercury lamps and xenon and tungsten lamps are advantageous. Also excimer, solid state and diode based lasers are advantageous. Diode-based light sources are generally advantageous for initiating chemical reactions.

Catheter

In the present invention, there is provided a urinary catheter comprising: the coating comprises a pipe body, a coating formed on the surface of the pipe body, and heparin and chitosan which are self-assembled on the outer surface of the coating layer by layer, wherein the coating is formed by a coating composition, the coating composition comprises at least one photocurable polymer, wherein,

the photocurable polymer is polymerized by components comprising water-soluble photosensitive monomers and hydrophilic monomers,

the water-soluble photosensitive monomer contains: 1) a unit containing a photosensitive structure; 2) a unit containing a quaternary ammonium salt structure; 3) a unit containing an unsaturated bond structure;

the unit containing the photosensitive structure is connected with the unit containing the quaternary ammonium salt structure through at least-C (═ O) -, and the unit containing the unsaturated bond structure is connected with the unit containing the photosensitive structure through the unit containing the quaternary ammonium salt structure.

Pipe body

In the present invention, the catheter body is not particularly limited, and any catheter used in the art, for example, a commercially available catheter without a coating layer may be used.

In addition, materials suitable for use in the production of catheters include polymers such as silicone, polyurethane, PVC, and the like.

Photocurable polymers

The present invention also provides a photocurable polymer. The coating is prepared by copolymerizing a water-soluble photosensitive monomer and a hydrophilic monomer, and has a photosensitive structural unit which can be used as a macromolecular photoinitiator, so that the use of a micromolecular photoinitiator can be reduced when the coating is prepared into a coating composition, the problems of residue, migration and the like of the micromolecular photoinitiator in a coating can be solved, and the coating has excellent biological safety and compatibility and is suitable for the medical field.

< Water-soluble photosensitive monomer >

The water-soluble photosensitive monomer contains: 1) a unit containing a photosensitive structure; 2) a unit containing a quaternary ammonium salt structure; 3) a unit containing an unsaturated bond structure; the unit containing a photosensitive structure is linked to the unit containing a quaternary ammonium salt structure at least through-C (═ O) -and the unit containing an unsaturated bond structure is linked to the unit containing a photosensitive structure at least through the unit containing a quaternary ammonium salt structure.

The molecular structure of the water-soluble photosensitive monomer contains quaternary ammonium salt ions and double bonds besides a photoinitiation unit (namely a unit of a photosensitive structure), so that the photosensitive monomer has water solubility and polymerizability, has good compatibility with aqueous resin, and can be polymerized onto a macromolecular chain of the resin, thereby effectively overcoming the defect that small molecules are easy to migrate to the surface of a product.

The existence of the quaternary ammonium salt can greatly improve the water solubility and simultaneously has certain antibacterial property. The unit containing a quaternary ammonium salt structure contains a quaternary ammonium salt group, and may contain several alkylene groups in addition to the quaternary ammonium salt group.

The unit having an unsaturated bond may be a polymerizable group having a double bond. Such reactive groups may allow the photoactive unit to be incorporated into the backbone of the polymer in the form of a repeating unit via free radical polymerization. The unit containing an unsaturated bond may be selected from units having a (meth) acrylate group. The existence of the polymerizable group can overcome the problems of toxicity and high mobility of the conventional small-molecule photoinitiator, promote the photoinitiator to be anchored in a polymer network, improve the material performance by copolymerizing with other monomers, and inhibit the undesirable volatilization caused by the residue of the small-molecule photoinitiator.

In the present invention, the unit having a photosensitive structure is directly bonded to the quaternary ammonium salt structure through a carbonyl group (-C (═ O) -), and the unit having an unsaturated bond is directly bonded to the unit having a photosensitive structure through the quaternary ammonium salt-containing structural unit. The connection mode provides the greatest opportunity for interaction among all structural units, is favorable for energy transfer, can generate free radical active species more and more quickly, and improves the initiation efficiency.

In a preferred embodiment of the present invention, the water-soluble photosensitive monomer has the following structural formula:

formula (I)

Wherein: r₁＝CH₃Or H;R₂and R₃Each independently selected from a straight chain alkyl group of 1 to 20 carbon atoms or a branched chain alkyl group having 3 to 20 carbon atoms; x is halogen; n is 1-10; m is 1-4; f is 1-3; preferably, R₂And R₃Similarly, X is bromo, n ═ 1, m ═ 1, f ═ 1; more preferably, R₂And R₃Is methyl or ethyl, X is bromine, n is 1, m is 1, and f is 1. The selection of the groups and the molecular chain length in the general formula is mainly the requirements of viscosity, initiation rate and mobility of the comprehensive product.

Further preferably, suitable water-soluble photosensitive monomers according to the present invention include one or more compounds of the following structure:

the water-soluble photosensitive monomer is obtained by performing acyl halide treatment on the molecular terminal of a compound containing a photosensitive structure, and then reacting the compound with (methyl) acrylate containing a tertiary amine group.

An exemplary reaction scheme for the water-soluble photosensitive monomer is as follows:

wherein R is₁And R₂The same as the definition of the general formula (I).

< hydrophilic monomer >

In the present invention, the hydrophilic monomer is mainly used to provide hydrophilicity to the photocurable polymer. The hydrophilic monomer is not particularly limited as long as it is a monomer that can dissolve 1g or more in 100g of water at 25 ℃. The hydrophilic monomer comprises one or more than two of unsaturated carboxylic acid, unsaturated carboxylate, unsaturated carboxylic ester, unsaturated acid hydroxyalkyl ester, unsaturated anhydride, unsaturated amide, unsaturated lactam and alkylene oxide.

As the hydrophilic monomer, vinylpyrrolidone is preferable. The structure of vinyl pyrrolidone (NVP) gives it and the polymers formed from it special properties: it is readily polymerized; the polymer formed by the polymer has excellent hydrophilicity, complexing ability, physiological compatibility and chemical stability; has no irritation to skin; has strong solubilization, can increase the water solubility of some substances which are basically insoluble in water but have pharmacological activity, and is suitable for medical use. Therefore, when vinylpyrrolidone is used as the hydrophilic monomer, the resulting lubricating coating has a better lubricating effect, and the specific phenotype is that the frictional force is low, and the frictional force hardly changes as the number of cycles increases.

Wherein the content of the water-soluble photosensitive monomer is 0.01-20 wt% of the total mass of the hydrophilic monomer.

< polymerization of Water-soluble photosensitive monomer and hydrophilic monomer >

The photocurable polymer is prepared by free radical polymerization of a water-soluble photosensitive monomer and a hydrophilic monomer. Wherein, the free radical polymerization includes but is not limited to common free radical polymerization and living controllable free radical polymerization.

The free-radical polymerization is carried out in a medium, such as solution polymerization, emulsion polymerization, inverse emulsion polymerization, suspension polymerization, bulk polymerization. From the viewpoint of ease of handling, it is preferable that the photocurable hydrophilic polymer is polymerized from a solution, and from the viewpoint of environmental protection, it is more preferable that the photocurable polymer is copolymerized in an aqueous solution. In one embodiment of the present invention, a photocurable polymer is obtained by dissolving a water-soluble photosensitive monomer and a hydrophilic monomer in water, adding a radical initiator into the system, removing oxygen, and reacting at a specific temperature.

The total monomers are contained in the aqueous solution at a concentration of 10 to 50 mass%, preferably 10 to 30 mass%, more preferably 12 to 20 mass%, based on the total weight of the aqueous solution.

The radical initiator in the polymerization reaction means a substance which generates radicals upon application of activation energy, and includes heat-activated initiators such as organic peroxides, organic hydroperoxides and azo compounds. Representative examples of such initiators include, but are not limited to, benzoyl peroxide, t-butyl perbenzoate, diisopropyl peroxydicarbonate, cumene hydroperoxide, azobisisobutyronitrile, and the like. The thermal initiator is generally used in an amount of 0.02 to 0.05 mass% based on the total mass of the monomers.

The photocurable polymer preferably has a number average molecular weight of at least 5 ten thousand, preferably a relatively high molecular weight, in order to reduce migration, but preferably 70 ten thousand or less in order to facilitate application of the coating. In order to obtain a hydrophilic coating having good lubricating properties even after many cycles, the photocurable polymer preferably has a number average molecular weight of 5 to 70 ten thousand, more preferably 10 to 50 ten thousand, and most preferably 30 to 40 ten thousand.

Coating composition

The coating composition of the present invention comprises at least one of the above-mentioned at least one photocurable polymer.

Any solvent suitable for use in the present invention is sufficient as long as it allows coating of the coating composition having hydrophilicity on the surface. Preferably, the solvent is one or a mixture of solvents that can dissolve the above photocurable polymer to form a homogeneous solution. Examples of the solvent include one or more of water, low molecular weight alcohols (methanol, ethanol, isopropanol, butanol, pentanol, ethylene glycol, propylene glycol, glycerol, etc.), ethyl acetate, N-hexane, dichloromethane, chloroform, N-dimethylformamide, N-dimethylacetamide, dimethylsulfoxide, acetone, diethyl ether, toluene, benzene, xylene, cyclohexane, phenol. The low-cost and pollution-free solvent suitable for dissolving and mixing the uniform formula is preferably a mixture of water and isopropanol, preferably the volume ratio of the water to the isopropanol is 1:10-10:1, and the solvent suitable for dissolving and mixing the uniform formula is more preferably the volume ratio of the water to the isopropanol is 1:5-5:1, and most preferably 2:3-3: 2.

Other additives such as support polymers, polyelectrolytes, wetting agents, leveling agents, defoamers, coalescents, thickeners, pigments, antimicrobials, colorants, surfactants, and the like may also be added to the coating composition as desired.

Heparin

Heparin, a natural glucan, acts as the same covering of urinary catheters and urinary tract wounds, inhibiting fibrin aggregation and adhesion of bacteria to the crystals.

The damage to the urinary tract caused by pathogenic microorganisms and many pathogenic factors causing urinary tract diseases is mostly initiated by the adhesion of pathogenic particles on the urinary tract epithelium, and when a catheter is inserted to cause trauma to the inner surface of the urinary tract, fibrin of a wound surface seeps out and coagulates into fibrin clots, so that bacteria and crystals are more easily adhered to the wound surface to cause infection. The sulfonic acid groups in aminodextran, such as heparin, adsorb water particles to form an electrically neutral inert barrier on the bladder surface, which serves as a first barrier to prevent bacteria and crystal particles from adhering.

Chitosan

Chitosan is an acylated chitin with a positive charge. The positive charges of the chitosan can interact with the negative charges on the surface of the microbial cell membrane, and the chitosan is adsorbed on the surface of the microbial cell to form a layer of polymer membrane, so that the permeability of the cell membrane is changed, and nutrient substances are prevented from being transported to the inside of the cell, thereby playing the roles of sterilization and bacteriostasis.

In some preferred embodiments, the chitosan used in the present invention has a molecular weight of 1500-.

Preparation method of catheter

The invention also provides a preparation method of the catheter, which comprises the following steps:

(i) forming the coating composition on the surface of the catheter body, and curing under the condition of illumination;

(ii) and (2) alternately self-assembling the heparin and the chitosan on the outer surface of the coating to form a heparin and chitosan double molecular layer, and repeating the alternate self-assembly for n times to form n layers of heparin and chitosan double molecular layers, wherein n is more than or equal to 1.

Wherein the coating composition is formed on the surface of the catheter body by one or more of brushing, dip coating, spraying, pouring and blade coating.

The light source used in illumination comprises any one of UV light source, visible light source and infrared light source(ii) a Preferably, the light source is a UV light source and a visible light source; more preferably a source of UV light. Preferably, the intensity of ultraviolet light during curing is 5-25mW/cm²The time for curing the coating composition is 2 to 7 minutes, preferably 3 to 5 minutes.

Preferably, the catheter is placed in a barrel containing the coating liquid composition, left standing for 2-7min, and the catheter is pulled at a speed of 0.5-1cm/s, and the intensity of ultraviolet light for the catheter with the coating liquid is 5-25mW/cm²Irradiating with ultraviolet lamp for 3-5min for curing.

The catheter coated with the lubricating coating is sequentially soaked in a heparin solution, water, a chitosan solution and water to obtain a layer of heparin and chitosan double molecular layer, and the process is repeated for n times to obtain the catheter deposited with n layers of heparin and chitosan double molecular layers. This step is also called layer-by-layer self-assembly, which is a simple and versatile surface modification method. It utilizes charged base material and makes the polyelectrolyte solution with opposite charges alternatively deposit to prepare polyelectrolyte self-assembled multilayer film.