Antibacterial catheter and preparation method thereof

Abstract

The invention discloses an antibacterial catheter and a preparation method thereof, belongs to the technical field of catheters, and aims to solve the problems of poor antibacterial effect and short duration caused by untight combination of an antibacterial agent and a thermoplastic polyurethane elastomer after antibacterial treatment of an existing catheter in the prior art. The antibacterial catheter comprises a catheter body and n antibacterial layers sequentially formed on the outer wall face of the catheter body, and n is a positive integer; the pipe body is made of a polyurethane elastomer; the antibacterial layer is prepared from the following materials in parts by mass: 100 parts of polyurethane elastomer and 1-10 parts of antibacterial agent, and the antibacterial agent is a pyrithione compound. Based on the multiple antibacterial layers and hydrogen bond bonding between the antibacterial agent and the polyurethane elastomer, the long-term antibacterial effect can be achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of catheters, and particularly relates to an antibacterial catheter and a preparation method thereof. Background Art

[0002] A catheter is a medical device used for clinical surgical drainage, which guides pus, blood, and fluid accumulated between human tissues or in body cavities to the outside of the body to prevent postoperative infections and promote wound healing. Polyurethane elastomer (PUE) is a commonly used material for catheters, which has good wear resistance, toughness, and processability.

[0003] Due to the low antibacterial activity of thermoplastic polyurethane elastomer, bacteria are likely to grow when the external environment is suitable, and it is necessary to incorporate antibacterial agents to improve the antibacterial activity of thermoplastic polyurethane elastomer.

[0004] However, directly adding antibacterial agents to thermoplastic polyurethane elastomer requires a large amount of antibacterial agents to be added, resulting in high costs. Moreover, the combination of antibacterial agents and thermoplastic polyurethane elastomer is not tight, leading to poor antibacterial effects and short durations. Summary of the Invention

[0005] In view of the above analysis, the present invention aims to provide an antibacterial catheter and a preparation method thereof to solve the problems in the prior art that the combination of antibacterial agents and thermoplastic polyurethane elastomer is not tight after antibacterial treatment of existing catheters, resulting in poor antibacterial effects and short durations.

[0006] The object of the present invention is mainly achieved through the following technical solutions.

[0007] The present invention provides an antibacterial catheter, including a tube body and n antibacterial layers sequentially formed on the outer wall surface of the tube body, where n is a positive integer;

[0008] The material of the tube body is polyurethane elastomer;

[0009] The material of the antibacterial layer includes 100 parts of polyurethane elastomer and 1 - 10 parts of antibacterial agent by mass, and the antibacterial agent is a pyrithione compound.

[0010] Further, in the antibacterial layer, there is a hydrogen bond bonding between the antibacterial agent molecules and the molecular chains of the polyurethane elastomer.

[0011] Further, the antibacterial agent content in the first antibacterial layer to the nth antibacterial layer gradually increases.

[0012] Further, the number of antibacterial layers is 2 - 4 layers.

[0013] Further, the number of antibacterial layers is 3 layers, which are respectively the first antibacterial layer, the second antibacterial layer, and the third antibacterial layer along the direction gradually away from the tube body.

[0014] Further, the mass fraction of the polyurethane elastomer in the first antibacterial layer is 100 parts, and the mass fraction of the antibacterial agent in the first antibacterial layer is 1 to 3 parts.

[0015] Further, the mass fraction of the polyurethane elastomer in the second antibacterial layer is 100 parts, and the mass fraction of the antibacterial agent in the second antibacterial layer is 4 to 6 parts.

[0016] Further, the mass fraction of the polyurethane elastomer in the third antibacterial layer is 100 parts, and the mass fraction of the antibacterial agent in the third antibacterial layer is 7 to 10 parts.

[0017] Further, the pyrithione compound is one or more of N-oxide-2-mercaptopyridine, sodium N-oxide-2-mercaptopyridine, zinc N-oxide-2-mercaptopyridine, and copper N-oxide-2-mercaptopyridine in any proportion.

[0018] The present invention also provides a preparation method of an antibacterial catheter for preparing the above-mentioned antibacterial catheter, and the preparation method includes the following steps:

[0019] Provide a tube body;

[0020] Form multiple antibacterial layers on the outer wall of the tube body in sequence.

[0021] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0022] A) For the antibacterial catheter provided by the present invention, multiple antibacterial layers are formed on the outer wall surface of the tube body, and the antibacterial agent molecules and the polyurethane elastomer molecular chains are effectively bonded through supramolecular forces (hydrogen bonds), so that the antibacterial agent and the polyurethane elastomer have excellent compatibility and adhesion. It can not only enhance the overall performance of the antibacterial layer, but also achieve a long-term antibacterial effect, inhibit the attachment and growth of bacteria, and reduce the risk of infection. At the same time, through the effective bonding of the antibacterial agent molecules and the polyurethane elastomer molecular chains, the antibacterial agent in the antibacterial layer will not be released into the external environment, thereby reducing the risk of pollution to the external environment.

[0023] B) In the antibacterial catheter provided by the present invention, the antibacterial layer is a multi-layer structure, and along the direction gradually away from the tube body, the content of the antibacterial agent in the multiple antibacterial layers gradually increases, which can realize the transition between the tube body and the antibacterial layer, improve the connection performance between the antibacterial layer and the tube body, and avoid the situation of the antibacterial layer falling off from the tube body. At the same time, the content of the antibacterial agent in the outermost antibacterial layer is the highest, so that on the basis of ensuring the antibacterial effect, the addition amount of the antibacterial agent can be effectively reduced.

[0024] C) The antibacterial catheter provided by the present invention uses pyrithione compounds as the antibacterial agent for the antibacterial layer. It is a low-toxic and effective antibacterial agent that can form hydrogen bond bonding with the polyurethane elastomer, has a high antibacterial effect, and can broadly inhibit the growth of various bacteria.

[0025] D) The preparation method of the antibacterial catheter provided by the present invention uses an automated coating assembly to replace the existing manual coating. In the liquid storage tube, since the density of the first-layer antibacterial layer material is greater than that of the nth-layer antibacterial layer material, the organic solvent solutions of the antibacterial agent materials from the first layer to the nth layer can be arranged from bottom to top in sequence. Then, the organic solvent solutions of the antibacterial agent materials in the liquid storage tube are successively coated on the tube body through a coating ring brush, realizing the coating of multiple antibacterial layers with one feeding.

[0026] In the present invention, the above technical solutions can also be combined with each other to achieve more preferred combination schemes. Other features and advantages of the present invention will be described in the subsequent specification, and some advantages can be made obvious from the specification, or understood by implementing the present invention. The objectives and other advantages of the present invention can be achieved and obtained from the content specifically pointed out in the embodiments of the specification and the drawings. Description of the Drawings

[0027] The drawings are only for the purpose of showing specific embodiments, and are not considered as a limitation to the present invention. Throughout the drawings, the same reference signs represent the same components.

[0028] Figure 1 It is a schematic structural diagram of the antibacterial catheter provided by the present invention;

[0029] Figure 2 It is a comparison diagram of infrared spectra of the antibacterial catheter prepared in Example 1 of the present invention and the initial comparison tube body;

[0030] Figure 3 It is a comparison diagram of the antibacterial rates of the antibacterial catheters prepared in Examples 1-3 and Comparative Example 1 of the present invention for 12 hours;

[0031] Figure 4 It is a comparison diagram of the antibacterial rates of the antibacterial catheters prepared in Examples 1-3 and Comparative Example 1 of the present invention for 15 days.

[0032] Reference Signs:

[0033] 1 - Tube body; 2 - First antibacterial layer; 3 - Second antibacterial layer; 4 - Third antibacterial layer. Detailed Embodiments

[0034] The preferred embodiments of the present invention will be specifically described below with reference to the accompanying drawings. The accompanying drawings form a part of the present invention and are used together with the embodiments of the present invention to explain the principles of the present invention, rather than to limit the scope of the present invention.

[0035] The present invention provides an antibacterial catheter. Referring to Figure 1 , it includes a tube body 1 and n antibacterial layers sequentially formed on the outer wall surface of the tube body 1, where n is a positive integer. The material of the tube body 1 is polyurethane elastomer. The material of the antibacterial layer includes 100 parts of polyurethane elastomer and 1 - 10 parts of antibacterial agent by mass. The antibacterial agent is a pyrithione compound. There is a hydrogen bond bonding between the antibacterial agent molecules and the molecular chains of the polyurethane elastomer. The antibacterial agent content in the first antibacterial layer to the nth antibacterial layer gradually increases.

[0036] Compared with the prior art, for the antibacterial catheter provided by the present invention, multiple antibacterial layers are formed on the outer wall surface of the tube body 1, and the antibacterial agent molecules and the polyurethane elastomer molecular chains are effectively bonded through supramolecular forces (hydrogen bonds), so that the antibacterial agent and the polyurethane elastomer have excellent compatibility and adhesion. It can not only enhance the overall performance of the antibacterial layer, but also achieve a long-term antibacterial effect, inhibit the attachment and growth of bacteria, and reduce the risk of infection. At the same time, through the effective bonding of the antibacterial agent molecules and the polyurethane elastomer molecular chains, the antibacterial agent in the antibacterial layer will not be released into the external environment, thereby reducing the risk of pollution to the external environment.

[0037] On the other hand, the antibacterial layer in the above antibacterial catheter is a multi-layer structure, and along the direction gradually away from the tube body 1, the antibacterial agent content in the multi-layer antibacterial layer gradually increases, which can realize the transition between the tube body 1 and the antibacterial layer, improve the connection performance between the antibacterial layer and the tube body 1, and avoid the situation that the antibacterial layer falls off from the tube body 1. At the same time, the antibacterial agent content in the outermost antibacterial layer is the highest, so that on the basis of ensuring the antibacterial effect, the addition amount of the antibacterial agent can be effectively reduced.

[0038] On the other hand, using a pyrithione compound as the antibacterial agent of the antibacterial layer, it is a low-toxic and effective antibacterial agent, which can form a hydrogen bond with the polyurethane elastomer and has a high antibacterial effect, and can broadly inhibit the growth of various bacteria.

[0039] Exemplarily, the number of antibacterial layers is 2 - 4 layers (for example, 3 layers).

[0040] Taking 3 layers as an example, referring to Figure 1, in the direction gradually away from the tube body 1, there are a first antibacterial layer 2, a second antibacterial layer 3, and a third antibacterial layer 4 respectively. Among them, the mass fraction of the polyurethane elastomer in the first antibacterial layer 2, the second antibacterial layer 3, and the third antibacterial layer 4 is 100 parts, the mass fraction of the antibacterial agent in the first antibacterial layer 2 is 1 - 3 parts, the mass fraction of the antibacterial agent in the second antibacterial layer 3 is 4 - 6 parts, and the mass fraction of the antibacterial agent in the third antibacterial layer 4 is 7 - 10 parts.

[0041] The present invention also provides a preparation method of an antibacterial catheter, including the following steps:

[0042] Step 1: Provide a coating assembly, which includes a coating ring brush, a liquid delivery ring, a liquid delivery pipe, and a liquid storage pipe. The liquid outlet end of the liquid storage pipe is connected to the liquid inlet of the liquid delivery ring through the liquid delivery pipe, and the coating ring brush is arranged on the inner wall of the liquid delivery ring;

[0043] Step 2: Sleeve the coating ring brush on the outer wall of the tube body 1;

[0044] Step 3: Sequentially add the organic solvent solutions of the antibacterial layer materials from the first layer to the nth layer into the liquid storage pipe;

[0045] Step 4: Drive the coating ring brush to reciprocate relative to the tube body 1. The organic solvent solution of the antibacterial layer material of the first layer in the liquid storage tank sequentially flows through the liquid delivery pipe and the liquid delivery ring to the coating ring brush, and the organic solvent solution of the antibacterial layer material of the first layer is completely coated on the tube body 1, and the coating ring brush stops sliding;

[0046] Step 5: Cure the first antibacterial layer;

[0047] Step 6: Drive the coating ring brush to reciprocate relative to the tube body 1. The organic solvent solution of the antibacterial layer material of the next layer in the liquid storage pipe sequentially flows through the liquid delivery pipe and the liquid delivery ring to the coating ring brush, and the organic solvent solution of the antibacterial layer material of the next layer is completely coated on the tube body 1, and the coating ring brush stops sliding;

[0048] Step 7: Cure the next antibacterial layer;

[0049] Step 8: Repeat Step 6 to Step 7 until the nth antibacterial layer is prepared to obtain an antibacterial catheter.

[0050] It should be noted that the density of the organic solvent solution of the antibacterial layer material can be regulated in the following ways:

[0051] Introduce branched chains with different densities into the polyurethane elastomer molecular chain, or realize density regulation by using organic solvents with different densities. All of them can be used, and will not be elaborated one by one here.

[0052] Compared with the prior art, the preparation method of the antibacterial catheter provided by the present invention uses an automated coating assembly to replace the existing manual coating. In the liquid storage tube, since the density of the first-layer antibacterial layer material is greater than that of the nth-layer antibacterial layer material, the organic solvent solutions of the antibacterial agent materials from the first layer to the nth layer can be arranged from bottom to top. Then, the organic solvent solutions of the antibacterial agent materials in the liquid storage tube are successively coated on the tube body 1 through a coating ring brush, realizing the coating of multiple antibacterial layers with one feeding.

[0053] In order to effectively cure the antibacterial layer, in the above steps 5 and 7, the curing includes the following steps:

[0054] The tube body 1 coated with the antibacterial agent is naturally dried at a temperature of 20 - 30 °C for 0.5 - 1.5 h to complete the first curing;

[0055] The tube body 1 after the first curing is vacuum dried at a temperature of 70 - 80 °C for 2 - 4 h to remove the organic solvent and complete the second curing.

[0056] Exemplarily, the preparation method of the organic solvent solution of the above antibacterial layer material includes the following steps:

[0057] Step a: Stir and react the hydroxyl-terminated polymer and the polyisocyanate to obtain a polyurethane prepolymer;

[0058] Step b: Add the organic solvent solution of the chain extender to the polyurethane prepolymer for reaction, and mix and stir to react to obtain the organic solvent solution of the polyurethane elastomer;

[0059] Step c: Add the organic solvent solution of the antibacterial agent to the organic solvent solution of the polyurethane elastomer for reaction to obtain the organic solvent solution of the antibacterial layer material.

[0060] Exemplarily, in the above steps, calculated by the mass percentage of the organic solvent solution of the polyurethane elastomer, the hydroxyl-terminated polymer is 63 - 87, the polyisocyanate is 11 - 31, the chain extender is 2 - 6, and the organic solvent is 0.02 - 0.06. Among them, the molar ratio of the isocyanate group (-NCO) in the polyisocyanate to the active hydrogen (-OH) in the chain extender is 1:1 - 1.1:1 (for example, 1:1, 1.05:1 or 1.1:1); calculated by the mass percentage of the organic solvent solution of the antibacterial agent, the antibacterial agent is 1 - 10, and the organic solvent is 90 - 99.

[0061] It should be noted that different from the existing methods of adding reactive antibacterial agents during the synthesis stage of polyurethane elastomers and melt-blending polyurethane elastomers with antibacterial agents, the preparation method of the organic solvent solution of the above antibacterial layer material adds antibacterial agents to polyurethane elastomers through a solution blending method, enabling antibacterial agent molecules to form hydrogen bonds with the molecular chains of polyurethane elastomers, thereby achieving a long-term antibacterial effect.

[0062] In order to ensure the yield of the polyurethane prepolymer, in the above step a, the reaction temperature is 70 - 80 °C, the reaction time is 1 - 2 h, and the reaction is carried out in a protective atmosphere.

[0063] Similarly, in order to ensure the yield of the organic solvent solution of the polyurethane elastomer, in the above step b, the reaction temperature is 70 - 80 °C, and the reaction time is 5 - 6 h.

[0064] In order to ensure the yield of the organic solvent solution of the antibacterial layer material, in the above step c, the reaction temperature is 70 - 80 °C, and the reaction time is 2 - 12 h.

[0065] In order to reduce the adverse effect of moisture in the hydroxyl-terminated polymer on the reaction, the following steps are also included before the above step a:

[0066] The hydroxyl-terminated polymer raw material is subjected to vacuum dehydration drying, with a pressure of 0.8 - 1 bar, a temperature of 98 - 102 °C (for example, 100 °C), and a time of 1.5 - 2.5 h (for example, 2 h);

[0067] The hydroxyl-terminated polymer raw material after vacuum dehydration drying is cooled to 75 - 85 °C (for example, 80 °C) to obtain a dried hydroxyl-terminated polymer.

[0068] Correspondingly, in order to reduce the adverse effect of moisture in the chain extender on the reaction, the following steps are also included between the above step a and step b:

[0069] The chain extender raw material is subjected to vacuum dehydration drying, with a pressure of 0.8 - 1 bar, a temperature of 98 - 102 °C (for example, 100 °C), and a time of 1.5 - 2.5 h (for example, 2 h);

[0070] The chain extender raw material after vacuum dehydration drying is cooled to 20 - 30 °C (for example, 25 °C) to obtain a dried chain extender.

[0071] Exemplarily, in the above step a, the molecular weight of the hydroxyl-terminated polymer is 1000 to 4000 g / mol, and the dispersity is 1.5 to 2. The hydroxyl-terminated polymer is one or more of polyether polyols and polyester polyols in any proportion. Among them, the polyether polyol is one or more of polydimethylsiloxane (PDMS), polytetrahydrofuran ether diol (PTMEG), polyethylene glycol (PEG), and polypropylene glycol (PPG) in any proportion, and the polyester polyol is one or more of polycaprolactone diol (PCL) and polyethylene terephthalate diol in any proportion.

[0072] The polyisocyanate is a bifunctional isocyanate. For example, it is one or more of toluene diisocyanate (TDI), isophorone diisocyanate (IPDI), diphenylmethane diisocyanate (MDI), dicyclohexylmethane diisocyanate (HMDI), and hexamethylene diisocyanate (HDI) in any proportion.

[0073] In the above step b, the chain extender is one or more of a glycol chain extender and a diamine chain extender in any proportion. Among them, the glycol chain extender is one or more of 1,4-butanediol, ethylene glycol, 1,3-propanediol, and neopentyl glycol in any proportion, and the diamine chain extender is one or more of diaminopyridine (DAP), diethyltoluenediamine (DETDA), and bis(sec-butylamino)diphenylmethane (MDBA) in any proportion.

[0074] In order to fully dissolve the chain extender, in the above step b, the organic solvent in the organic solvent solution of the chain extender is one or more of tetrahydrofuran (THF), N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMAC), and dimethyl sulfoxide (DMSO) in any proportion.

[0075] Correspondingly, for the antibacterial agent, the pyrithione compounds are one or more of N-oxide-2-mercaptopyridine (pyrithione, abbreviated as PT), sodium N-oxide-2-mercaptopyridine (sodium pyrithione, abbreviated as SPT), zinc N-oxide-2-mercaptopyridine (zinc pyrithione, abbreviated as ZPT), and copper N-oxide-2-mercaptopyridine (copper pyrithione, abbreviated as CPT) in any proportion.

[0076] In order to fully dissolve the antibacterial agent, in the above step c, the organic solvent in the organic solvent solution of the antibacterial agent is one or more of carbon tetrachloride (TCC), tetrahydrofuran (THF), acetone (ACE), toluene (TOL), and dioxane (DIOX) in any proportion.

[0077] It should be noted that among the components used in the present invention, unless otherwise specified, they can all be obtained by commercial purchase.

[0078] Example 1

[0079] The preparation method of the antibacterial catheter provided in this example includes the following steps:

[0080] Step A: Prepare the organic solvent solutions of the first-layer antibacterial agent material, the second-layer antibacterial agent material, and the third-layer antibacterial agent material respectively;

[0081] Cut the TPU tube into small sections 20 mm long as the tube body, ultrasonically clean the surface of the tube with deionized water 3 times, 5 s each time, and after taking it out, wipe and suck the water on the surface of the tube body with a tissue;

[0082] Step B: Slip the coating ring brush onto the outer wall of the tube body;

[0083] Step C: Add the organic solvent solutions of the first-layer antibacterial agent material, the second-layer antibacterial agent material, and the third-layer antibacterial agent material into the liquid storage tube in sequence;

[0084] Step D: Drive the coating ring brush to reciprocate relative to the tube body. The organic solvent solution of the first-layer antibacterial layer material in the liquid storage tank flows through the liquid delivery tube and the liquid delivery loop to the coating ring brush in sequence, and all the organic solvent solution of the first-layer antibacterial layer material is coated on the tube body, and the coating ring brush stops sliding;

[0085] Step E: Dry the tube body coated with the first-layer antibacterial layer at a temperature of 25 °C for 1 h, and then vacuum dry it at a temperature of 80 °C for 3 h;

[0086] Step F: Drive the coating ring brush to reciprocate relative to the tube body. The organic solvent solution of the second-layer antibacterial layer material in the liquid storage tube flows through the liquid delivery tube and the liquid delivery loop to the coating ring brush in sequence, and all the organic solvent solution of the second-layer antibacterial layer material is coated on the tube body, and the coating ring brush stops sliding;

[0087] Step G: Dry the tube body coated with the second-layer antibacterial layer at a temperature of 25 °C for 1 h, and then vacuum dry it at a temperature of 80 °C for 3 h;

[0088] Step H: Drive the coating ring brush to reciprocate relative to the tube body. The organic solvent solution of the third-layer antibacterial layer material in the liquid storage tube flows through the liquid delivery tube and the liquid delivery loop to the coating ring brush in sequence, and all the organic solvent solution of the third-layer antibacterial layer material is coated on the tube body, and the coating ring brush stops sliding;

[0089] Step I: Dry the tube body coated with the third-layer antibacterial layer at a temperature of 25 °C for 1 h, and then vacuum dry it at a temperature of 80 °C for 3 h to obtain the antibacterial catheter.

[0090] The preparation methods and process parameters of the organic solvent solutions of the antibacterial agent materials for the first layer, the second layer, and the third layer are basically the same, as follows:

[0091] Dehydrate and dry PTMEG (hydroxyl-terminated polymer) under reduced pressure at 100 °C and 0.8 bar for 2 h. After it cools down to 80 °C, add 4,4'-diphenylmethane diisocyanate (polyisocyanate) that has been pre-heated and melted. Stir and react at 80 °C for 1 h. Titrate the content of 4,4'-diphenylmethane diisocyanate by the dibutylamine-acetone method. When it reaches the predetermined value, stop the reaction to obtain a polyurethane prepolymer;

[0092] Dehydrate and dry 1,4-butanediol (chain extender) under reduced pressure at 100 °C and 0.8 bar for 2 h. After it cools down to 25 °C, completely dissolve it with N,N-dimethylformamide (organic solvent);

[0093] Add the N,N-dimethylformamide solution of 1,4-butanediol to the polyurethane prepolymer. Stir and react at 80 °C for 6 h to obtain an organic solvent solution of polyurethane elastomer;

[0094] Add the tetrahydrofuran solution of zinc pyrithione (antibacterial agent) to the organic solvent solution of polyurethane elastomer. Stir and react at 80 °C for 8 h to obtain an antibacterial layer material.

[0095] Among them, in the organic solvent solution of polyurethane elastomer, calculated by mass percentage, the hydroxyl-terminated polymer is 63, the polyisocyanate is 31, the chain extender is 5.98, and the organic solvent is 0.02. In the organic solvent solution of the antibacterial agent, calculated by mass percentage, the antibacterial agent is 10 and the organic solvent is 90.

[0096] In the first-layer antibacterial layer material, the mass ratio of polyurethane elastomer to zinc pyrithione is 100:1; in the second-layer antibacterial layer material, the mass ratio of polyurethane elastomer to zinc pyrithione is 100:5; in the third-layer antibacterial layer material, the mass ratio of polyurethane elastomer to zinc pyrithione is 100:10.

[0097] Example 2

[0098] The preparation method of the antibacterial catheter provided in this example includes the following steps:

[0099] Step A: Prepare the organic solvent solutions of the antibacterial agent materials for the first layer, the second layer, and the third layer respectively;

[0100] Cut the TPU tube into small sections 20 mm long as the tube body. Ultrasonically clean the surface of the tube with deionized water 2 times, 10 s each time. After taking it out, wipe and suck the moisture on the surface of the tube body with a tissue;

[0101] Step B: Slip the coating ring brush onto the outer wall of the tube body;

[0102] Step C: Sequentially add the organic solvent solution of the first-layer antibacterial agent material, the organic solvent solution of the second-layer antibacterial agent material, and the organic solvent solution of the third-layer antibacterial agent material into the liquid storage tube;

[0103] Step D: Drive the coating ring brush to reciprocate relative to the tube body. The organic solvent solution of the first-layer antibacterial layer material in the liquid storage tank sequentially passes through the liquid delivery tube and the liquid delivery circulation ring to the coating ring brush, and all the organic solvent solution of the first-layer antibacterial layer material is coated on the tube body. Then the coating ring brush stops sliding;

[0104] Step E: Dry the tube body coated with the first-layer antibacterial layer at a temperature of 30°C for 0.5 h, and then vacuum dry it at a temperature of 80°C for 2 h;

[0105] Step F: Drive the coating ring brush to reciprocate relative to the tube body. The organic solvent solution of the second-layer antibacterial layer material in the liquid storage tube sequentially passes through the liquid delivery tube and the liquid delivery circulation ring to the coating ring brush, and all the organic solvent solution of the second-layer antibacterial layer material is coated on the tube body. Then the coating ring brush stops sliding;

[0106] Step G: Dry the tube body coated with the second-layer antibacterial layer at a temperature of 30°C for 0.5 h, and then vacuum dry it at a temperature of 80°C for 2 h;

[0107] Step H: Drive the coating ring brush to reciprocate relative to the tube body. The organic solvent solution of the third-layer antibacterial layer material in the liquid storage tube sequentially passes through the liquid delivery tube and the liquid delivery circulation ring to the coating ring brush, and all the organic solvent solution of the third-layer antibacterial layer material is coated on the tube body. Then the coating ring brush stops sliding;

[0108] Step I: Dry the tube body coated with the third-layer antibacterial layer at a temperature of 30°C for 0.5 h, and then vacuum dry it at a temperature of 80°C for 2 h to obtain the antibacterial catheter.

[0109] The preparation methods and process parameters of the organic solvent solutions of the first-layer antibacterial agent material, the second-layer antibacterial agent material, and the third-layer antibacterial agent material are basically the same, as follows:

[0110] Subject PDMS (hydroxyl-terminated polymer) to vacuum dehydration drying at 98°C and 0.8 bar for 2.5 h. After it cools down to 75°C, add the pre-heated and melted toluene diisocyanate (polyisocyanate), stir and react at 75°C for 1.5 h, titrate the toluene diisocyanate content by the di-n-butylamine acetone method. When it reaches the predetermined value, stop the reaction to obtain the polyurethane prepolymer;

[0111] The ethylene glycol (chain extender) was dehydrated and dried under reduced pressure at 98 °C and 0.8 bar for 2.5 h. After it was cooled to 20 °C, it was completely dissolved with tetrahydrofuran (organic solvent).

[0112] The tetrahydrofuran solution of ethylene glycol was added to the polyurethane prepolymer, and after stirring and reacting at 75 °C for 5 h, an organic solvent solution of polyurethane elastomer was obtained.

[0113] The dioxane solution of sodium pyrithione (antibacterial agent) was added to the organic solvent solution of polyurethane elastomer, and after stirring and reacting at 75 °C for 12 h, an antibacterial layer material was obtained.

[0114] Among them, in the organic solvent solution of polyurethane elastomer calculated by mass percentage, the hydroxyl-terminated polymer is 77, the polyisocyanate is 18, the chain extender is 4.95, and the organic solvent is 0.05; in the organic solvent solution of antibacterial agent calculated by mass percentage, the antibacterial agent is 5 and the organic solvent is 95.

[0115] In the first-layer antibacterial layer material, the mass ratio of polyurethane elastomer to zinc pyrithione is 100:3; in the second-layer antibacterial layer material, the mass ratio of polyurethane elastomer to zinc pyrithione is 100:4; in the third-layer antibacterial layer material, the mass ratio of polyurethane elastomer to zinc pyrithione is 100:8.

[0116] Example 3

[0117] The preparation method of the antibacterial catheter provided in this example includes the following steps:

[0118] Step A: Prepare the organic solvent solutions of the first-layer antibacterial agent material, the second-layer antibacterial agent material, and the third-layer antibacterial agent material respectively;

[0119] The TPU tube was cut into small sections 20 mm long as the tube body, and the surface of the tube was ultrasonically cleaned with deionized water 4 times, 3 s each time. After taking it out, the moisture on the surface of the tube body was wiped and sucked dry with a paper towel;

[0120] Step B: The coating ring brush was sleeved on the outer wall of the tube body;

[0121] Step C: The organic solvent solutions of the first-layer antibacterial agent material, the second-layer antibacterial agent material, and the third-layer antibacterial agent material were successively added into the liquid storage tube;

[0122] Step D: The coating ring brush was driven to reciprocate relative to the tube body. The organic solvent solution of the first-layer antibacterial layer material in the liquid storage tank successively passed through the liquid delivery pipe and the liquid delivery circulation ring to the coating ring brush, and all the organic solvent solution of the first-layer antibacterial layer material was coated on the tube body, and the coating ring brush stopped sliding;

[0123] Step E: Dry the tube body coated with the first antibacterial layer at a temperature of 20°C for 1.5 h, and then, under vacuum, dry it at a temperature of 70°C for 4 h;

[0124] Step F: Drive the coating ring brush to reciprocate relative to the tube body. The organic solvent solution of the second antibacterial layer material in the liquid storage tube sequentially passes through the liquid delivery tube and the liquid delivery circulation to the coating ring brush, and all the organic solvent solution of the second antibacterial layer material is coated on the tube body, and the coating ring brush stops sliding;

[0125] Step G: Dry the tube body coated with the second antibacterial layer at a temperature of 20°C for 1.5 h, and then, under vacuum, dry it at a temperature of 70°C for 4 h;

[0126] Step H: Drive the coating ring brush to reciprocate relative to the tube body. The organic solvent solution of the third antibacterial layer material in the liquid storage tube sequentially passes through the liquid delivery tube and the liquid delivery circulation to the coating ring brush, and all the organic solvent solution of the third antibacterial layer material is coated on the tube body, and the coating ring brush stops sliding;

[0127] Step I: Dry the tube body coated with the third antibacterial layer at a temperature of 20°C for 1.5 h, and then, under vacuum, dry it at a temperature of 70°C for 4 h to obtain an antibacterial catheter.

[0128] The preparation methods and process parameters of the organic solvent solutions of the first antibacterial agent material, the second antibacterial agent material, and the third antibacterial agent material are basically the same, as follows:

[0129] Subject PTMEG (hydroxyl-terminated polymer) to vacuum dehydration drying at 102°C and 1.0 bar for 1.5 h. After it cools down to 75°C, add the pre-heated and melted dicyclohexylmethane diisocyanate (polyisocyanate), and stir and react at 70°C for 2.5 h. Titrate the content of dicyclohexylmethane diisocyanate by the dibutylamine acetone method. When the predetermined value is reached, stop the reaction to obtain a polyurethane prepolymer;

[0130] Subject 1,4-butanediol (chain extender) to vacuum dehydration drying at 102°C and 1.0 bar for 1.5 h. After it cools down to 30°C, completely dissolve it with carbon tetrachloride (organic solvent);

[0131] Add the carbon tetrachloride solution of 1,4-butanediol to the polyurethane prepolymer, and stir and react at 70°C for 6 h to obtain an organic solvent solution of polyurethane elastomer;

[0132] Add the N,N-dimethylformamide solution of copper pyrithione (antibacterial agent) to the organic solvent solution of polyurethane elastomer, and stir and react at 70°C for 5 h to obtain an antibacterial layer material.

[0133] Among them, in the organic solvent solution of the polyurethane elastomer calculated by mass percentage, the hydroxyl-terminated polymer is 87, the polyisocyanate is 11, the chain extender is 2.97, and the organic solvent is 0.03; in the organic solvent solution of the antibacterial agent calculated by mass percentage, the antibacterial agent is 1 and the organic solvent is 99.

[0134] In the first-layer antibacterial layer material, the mass ratio of the polyurethane elastomer to zinc pyrithione is 100:2; in the second-layer antibacterial layer material, the mass ratio of the polyurethane elastomer to zinc pyrithione is 100:6; in the third-layer antibacterial layer material, the mass ratio of the polyurethane elastomer to zinc pyrithione is 100:7.

[0135] Comparative Example 1

[0136] The preparation method of the antibacterial catheter provided in this comparative example includes the following steps:

[0137] Step A: An antibacterial catheter was prepared by an existing melt blending method according to a mass ratio of polyurethane elastomer to zinc pyrithione of 100:5.

[0138] Infrared characterizations were respectively performed on the initial tube body and the antibacterial catheter prepared in Example 1. As Figure 2 shown, the absorption peak of isocyanate at about 2200 cm -1 completely disappeared, there was an obvious C=O vibration peak between 1650 and 1750 cm -1 , and there was an N-H bending vibration peak at about 1540 cm -1 . This indicates that the isocyanate has reacted with the hydroxyl group to form a urethane bond, proving the formation of the polyurethane structure. Compared with the tube body, the infrared characteristic peaks of the antibacterial catheter changed, proving that the antibacterial layer has been successfully coated on the surface of the tube body, meeting the designed structural characteristics.

[0139] The antibacterial catheters prepared in Examples 1 to 3 and Comparative Example 1 were tested for antibacterial activity by the surface contact method: The bacterial suspension (Escherichia coli or Staphylococcus aureus) was cultured in Mueller-Hinton Broth (MHB) medium at 37 °C until the optical density at 600 nm reached 0.8, entering the logarithmic growth phase. The bacterial cells were collected at 4 °C, washed with sterile PBS (pH 7.4), and suspended in PBS to a final concentration of 6×10 6 cells / mL. The antibacterial catheters of Examples 1 to 3 and Comparative Example 1 (with an area of 0.01 - 0.04 cm 2 ) were added to 50 μL of the bacterial suspension and shaken at 37 °C for 4 h. Then, 25 μL of the suspension was inoculated onto sterile LB culture dishes at a series of gradient concentrations (×1, ×10, ×100, ×1000).

[0140] After incubation at 37 °C for 12 h, the bacterial colonies were counted, and Examples 1-3 were compared with Comparative Example 1. See Figure 3 . From Figure 3 It can be seen that the antibacterial rates of Examples 1-3 and Comparative Example 1 against Escherichia coli and Staphylococcus aureus can both reach 100%.

[0141] Examples 1-3 and Comparative Example 1 were respectively added to 50 μL of the bacterial suspension, shaken for 15 days, taken out, rinsed with water, and then added to 50 μL of the freshly prepared bacterial suspension (the method for preparing the bacterial suspension is as described above). Shake at 37 °C for 4 h. Then, 25 μL of the suspension was inoculated on a sterile LB culture dish at a series of gradient concentrations (×1, ×10, ×100, ×1000). After incubation at 37 °C for 12 h, the bacterial colonies were counted, and Examples 1-3 were compared with Comparative Example 1. See Figure 4 . From Figure 4 It can be seen that the antibacterial rates of Examples 1-3 against Escherichia coli and Staphylococcus aureus can still remain above 76%, while the antibacterial rates of Comparative Example 1 against Escherichia coli and Staphylococcus aureus have significantly decreased to below 20%.

[0142] As described above, the above are only the preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention should be covered by the protection scope of the present invention.

Claims

1. An antibacterial catheter, characterized in that, It includes a tube body and n antibacterial layers formed successively on the outer wall surface of the tube body, where n is a positive integer; The material of the tube body is polyurethane elastomer; The material of the antibacterial layer includes 100 parts of polyurethane elastomer and 1 - 10 parts of antibacterial agent by mass. The antibacterial agent is a pyrithione compound.

2. The antibacterial catheter according to claim 1, wherein, In the antibacterial layer, there is a hydrogen bond between the antibacterial agent molecules and the molecular chains of the polyurethane elastomer.

3. The antibacterial catheter according to claim 1, wherein The antibacterial agent content in the 1st antibacterial layer to the nth antibacterial layer gradually increases.

4. The antibacterial catheter according to claim 3, wherein The number of the antibacterial layers is 2 - 4 layers.

5. The antibacterial catheter according to claim 4, characterized in that, The number of the antibacterial layers is 3 layers, which are respectively the first antibacterial layer, the second antibacterial layer, and the third antibacterial layer along the direction gradually away from the tube body.

6. The antibacterial catheter according to claim 5, characterized in that, The mass fraction of polyurethane elastomer in the first antibacterial layer is 100 parts, and the mass fraction of antibacterial agent in the first antibacterial layer is 1 - 3 parts.

7. The antibacterial catheter according to claim 5, wherein, The mass fraction of polyurethane elastomer in the second antibacterial layer is 100 parts, and the mass fraction of antibacterial agent in the second antibacterial layer is 4 - 6 parts.

8. The antibacterial catheter according to claim 5, characterized in that, The mass fraction of polyurethane elastomer in the third antibacterial layer is 100 parts, and the mass fraction of antibacterial agent in the third antibacterial layer is 7 - 10 parts.

9. The antibacterial catheter according to any one of claims 1 to 8, characterized in that, The pyrithione compound is one or a mixture of any proportion of N - oxide - 2 - mercapto pyridine, sodium N - oxide - 2 - mercapto pyridine, zinc N - oxide - 2 - mercapto pyridine, and copper N - oxide - 2 - mercapto pyridine.

10. A preparation method of an antibacterial catheter, characterized in that, For the preparation of the antibacterial catheter according to any one of claims 1 to 5, the preparation method includes the following steps: Provide a tube body; Form multiple antibacterial layers successively on the outer wall of the tube body.

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