Guide wire with firm hydrophilic coating and preparation method thereof

Abstract

The invention discloses a guide wire, and particularly relates to a guide wire with a firm hydrophilic coating and a preparation method of the guide wire. Aiming at the problems that the hydrophilic coating guide wire is easy to breed bacteria and the biocompatibility of an antibacterial agent is poor, the antibacterial agent in the coating is not released in a human body and is released in absolute ethyl alcohol, and a release channel is closed in water vapor through simple water vapor treatment, so that specific release and closing of the antibacterial agent in the coating of the guide wire are realized; the problems of antibacterial property, repairability, antibacterial agent release control and the like of the guide wire are solved, and a new solution is provided for the surface coating technology of medical instruments.

Description

Technical Field

[0001] The present invention relates to a guide wire, and particularly to a guide wire with a firm hydrophilic coating and a preparation method thereof. Background Art

[0002] With the continuous development of medical technology, medical devices are increasingly widely used in clinical treatment. In particular, medical devices such as guide wires, catheters, and stents that are long-term implanted in the body, their surface properties directly affect the treatment effect and postoperative recovery of patients. However, existing medical device surface coating technologies still face many challenges in improving the performance and safety of devices. Specifically, traditional coating technologies have the following technical problems:

[0003] (1) Insufficient antibacterial property

[0004] Although many existing coating technologies have tried to prevent bacteria attachment by introducing antibacterial components, the antibacterial properties of these coatings usually have problems such as short duration and uneven release rate. In addition, after the surface of the coating is damaged, the antibacterial components will quickly become ineffective, resulting in bacterial growth, which in turn causes infections or other complications. Traditional coating technologies are difficult to meet the antibacterial requirements of medical devices during long-term use. Especially in the case of long-term indwelling devices, the maintenance of antibacterial effect is particularly important.

[0005] (2) Balance problem between hydrophilicity and antibacterial property

[0006] On the surface of many medical devices, hydrophilic coatings are widely used to improve the lubricity and biocompatibility of the devices. However, hydrophilic coatings usually lack antibacterial properties and are prone to becoming carriers for bacteria attachment, thus causing infections. Existing hydrophilic coating technologies cannot effectively balance the relationship between hydrophilicity and antibacterial property. Therefore, how to add antibacterial components to the hydrophilic coating and maintain its functionality has become an urgent technical problem to be solved.

[0007] (3) Coating damage and repair problem

[0008] During long-term use, especially when in contact with the in-vivo environment, the surface coatings of medical devices are prone to wear, scratch or peeling, thus reducing their performance. For example, when a guide wire is inserted into a blood vessel or a cavity, it is easily rubbed and damaged, resulting in the loss of the lubricating effect of the coating. Traditional coating technologies generally have difficulty in achieving self-repair after damage. After the coating is damaged, the risk of loss of function or bacterial infection increases.

[0009] (4) Over-release and toxicity problems of antibacterial agents

[0010] The release of antibacterial agents on the surface of medical devices requires precise control. Excessive or premature release of antibacterial agents may be toxic to the human body and even cause cell damage. Especially in medical devices that are in long-term contact with the internal environment of the body, how to control the release rate and release timing of antibacterial agents to avoid excessive release or inactivation is a difficult problem faced by current technologies. In existing technologies, although some antibacterial coating technologies attempt to control the release of antibacterial agents through encapsulation or carrier release, they still cannot effectively balance the persistence and safety of antibacterial agents in practical applications.

[0011] To address the above problems, researchers in this field are exploring various technical solutions, attempting to combine functions such as antibacterial, hydrophilic, and self-healing to improve the performance of the coating. In particular, through means such as nanotechnology, microencapsulation technology, and reversible chemical reactions, new coating materials are designed to provide long-term antibacterial protection and be able to self-heal after damage. At the same time, how to precisely control the release mechanism of antibacterial agents to avoid their improper release in the internal environment of the body is also an important direction of current research.

[0012] In this context, the present invention proposes an antibacterial coating with self-healing function and its preparation method, aiming to solve problems such as antibacterial property, reparability, and control of antibacterial agent release in existing technologies, and providing a new solution for the surface coating technology of medical devices. Summary of the Invention

[0013] Aiming at the deficiencies in existing technologies, the technical problem to be solved by the present invention is: antibacterial components such as metal ions (such as silver, copper, etc.) and antibiotics may be toxic to the human body in excessive amounts, affecting biocompatibility and even causing adverse reactions. So, how to balance antibacterial performance and biocompatibility to avoid toxicity during long-term use.

[0014] A preparation method of a guide wire with a firm hydrophilic coating includes the following steps:

[0015] (1) Dissolve the substrate material in isopropanol, with the concentration of the substrate material being 10 - 15 wt%, and stir until completely dissolved to obtain a substrate solution;

[0016] (2) Add a crosslinking agent to the substrate solution obtained in step (1), and react at 50 - 60 °C for 30 - 40 min to obtain a self-healing coating solution;

[0017] (3) Add antibacterial agent microcapsules to the self-healing coating solution obtained in step (2) and disperse evenly to obtain a self-healing polymer solution;

[0018] (4) Degrease the guide wire with absolute ethanol and wash it with water, and then coat the self-healing polymer solution obtained in step (3), with the coating thickness being 10 - 50 microns;

[0019] (5) Place the coated guide wire in an oven and cure it at 80 - 90 °C for 1 - 2 h, then cool it to room temperature to obtain the guide wire with a firm hydrophilic coating.

[0020] The matrix material in step (1) is composed of polycaprolactam and polycaprolactone mixed in a mass ratio of (60 - 80):(20 - 40).

[0021] The crosslinking agent in step (2) is composed of diphenyl ether and maleic anhydride mixed in a mass ratio of (1 - 2):1.

[0022] The concentration of the antibacterial agent microcapsules in the self - healing polymer solution in step (3) is 2 - 4 wt%.

[0023] The preparation method of the antibacterial agent microcapsules includes the following steps:

[0024] S1 Dissolve 0.1 - 0.5 g of antibacterial agent and 1 - 2 g of polylactic acid in 20 - 30 mL of dichloromethane, add 0.5 - 1 mL of an aqueous solution of polyvinyl alcohol with a concentration of 1 - 2 wt%, stir at a speed of 800 - 1200 r / min for 30 - 60 min to form an emulsion, and leave the emulsion to stand at 1 - 4 °C for 12 - 24 h to obtain an antibacterial agent microcapsule emulsion;

[0025] S2 Centrifuge the antibacterial agent microcapsule emulsion obtained in step S1 at a speed of 5000 - 10000 r / min for 10 - 15 min, collect the antibacterial agent microcapsule particles, wash them 1 - 2 times with water, and dry them at 40 - 50 °C for 8 - 12 h to obtain the antibacterial agent microcapsules.

[0026] The antibacterial agent in step S1 is at least one of silver nanoparticles, copper nanoparticles, and natural antibacterial extracts; due to the broadest antibacterial effect of silver nanoparticles, preferably, the antibacterial agent in step S1 is silver nanoparticles.

[0027] In the present invention:

[0028] According to the design of the newly prepared guide wire coating, the release of the antibacterial agent is controllable, and the antibacterial agent will not be released in the normal human body environment.

[0029] The coating materials selected in the present invention are polycaprolactam and polycaprolactone, and the carrier of the antibacterial agent is a polylactic acid-polyethylene microcapsule, which has good biocompatibility and will not react with the surrounding tissues in the human body. Therefore, the coating remains stable. The antibacterial agent microcapsules are embedded in the self-healing coating, and the coating uses materials with dynamic cross-linking properties, diphenyl ether and maleic anhydride, that is, Diels-Alder reaction cross-linking agents. Under conventional physiological conditions (such as temperature, pH value, and salt concentration), these cross-linking agents can maintain the integrity of the coating, thus avoiding the release of the antibacterial agent. The purpose is to prevent the release of the antibacterial agent in the human body, improve biological safety, and not affect human safety.

[0030] In addition, since the coating matrix materials, polycaprolactam and polycaprolactone, have low solubility in absolute ethanol, and in this solvent, the cross-linked structure of the coating will dissociate, resulting in the release of the antibacterial agent microcapsules. Thus, the guide wire with a firm hydrophilic coating prepared in the present invention can be directly immersed in absolute ethanol after simple cleaning after use, so that the antibacterial agent in the coating is released. Under the dual action of absolute ethanol and the antibacterial agent in the coating, most bacteria can be eliminated, effectively preventing cross-infection.

[0031] Furthermore, when the guide wire needs to be used again, since absolute ethanol destroys the structure of the coating, causing the release of the antibacterial agent and a decrease in biocompatibility, it will pose a potential hazard to human safety. The guide wire with a firm hydrophilic coating prepared in the present invention can reactivate the Diels-Alder cross-linking reaction by exposing the coating to appropriate temperature and environmental conditions, repair the coating, and close the release channel of the antibacterial agent, restoring the structure of the coating. Through experiments, it is found that the temperature condition for the Diels-Alder cross-linking reaction is 100 - 150 °C, and the temperature of water vapor is 120 °C. In a water vapor environment of 120 °C, the cross-linked polymer coating can undergo a Diels-Alder reverse reaction, thus breaking the original cross-linked structure and releasing the antibacterial agent. Water vapor can not only provide sufficient heat but also may help the coating to change through its humidity effect. Once the cross-linking dissociates, the exposed molecular structure can be repaired again by thermal activation. For the cross-linking agent in the coating, water vapor at 120 °C can promote the reversal of the Diels-Alder reaction, allowing it to reform the cross-linked structure, seal the antibacterial agent, and restore the integrity of the coating.

[0032] Water vapor at 120 °C can provide sufficient heat to activate the Diels - Alder reverse reaction in the coating and accelerate the dissociation of the cross - linked structure through hydrothermal action, thereby releasing the antibacterial agent. At the same time, the cross - linked structure of the coating can also self - repair in this environment, restore its original functionality, and prevent the continuous release of the antibacterial agent. Therefore, only by treating the guide wire with a firm hydrophilic coating prepared by the present invention with water vapor for 5 - 10 min before use, the repair reaction can be promoted, thereby restoring the integrity of the coating and closing the antibacterial agent release channel.

[0033] In summary, the guide wire with a firm hydrophilic coating prepared by the present invention realizes the controlled release of the antibacterial agent through specific coating materials and antibacterial agent carriers. Aiming at the problems that hydrophilic - coated guide wires are prone to bacterial growth and the biocompatibility of antibacterial agents is poor, the present invention can achieve that the antibacterial agent in the coating does not release in the human body, releases in absolute ethanol, and closes the release channel in water vapor through simple water vapor treatment, thereby realizing the specific release and closing of the antibacterial agent in the guide wire coating, solving problems such as the antibacterial property, reparability, and release control of the antibacterial agent of the guide wire, and providing a new solution for the surface coating technology of medical devices. Detailed implementation mode

[0034] Polycaprolactam, product number: XY45091, Shanghai Xuanya Biotechnology Co., Ltd.

[0035] Polycaprolactone, product number: YS - PCL2101, Chongqing Yusai Medical Technology Co., Ltd.

[0036] Silver nanoparticles, product number: S7805, Beijing Solarbio Science & Technology Co., Ltd.

[0037] Polylactic acid, product number: YS - PLA20, Chongqing Yusai Medical Technology Co., Ltd.

[0038] Polyvinyl alcohol, product number: HBY0216, Hunan Huibaiyi New Materials Co., Ltd.

[0039] Guide wire: Medical guide wire, made of 304 stainless steel, with a diameter of 1 mm.

[0040] Example 1

[0041] A preparation method of a guide wire with a firm hydrophilic coating, comprising the following steps:

[0042] (1) Dissolve the matrix material in isopropanol, with the concentration of the matrix material being 12 wt%, and stir until completely dissolved to obtain a substrate solution;

[0043] (2) Add a cross - linker to the substrate solution obtained in step (1), and react at 55 °C for 35 min to obtain a self - repairing coating solution;

[0044] (3) Add the antibacterial microcapsules to the self-healing coating solution obtained in step (2) and disperse evenly to obtain a self-healing polymer solution;

[0045] (4) Degrease the guide wire with absolute ethanol and wash it with water, then apply the self-healing polymer solution obtained in step (3), and the coating thickness is 40 microns;

[0046] (5) Place the coated guide wire in an oven, cure it at 85 °C for 2 h, and cool it to room temperature to obtain the guide wire with a firm hydrophilic coating.

[0047] The matrix material in step (1) is composed of polycaprolactam and polycaprolactone mixed in a mass ratio of 70:30.

[0048] The cross-linking agent in step (2) is composed of diphenyl ether and maleic anhydride mixed in a mass ratio of 1:1.

[0049] The concentration of the antibacterial microcapsules in the self-healing polymer solution in step (3) is 3 wt%.

[0050] The preparation method of the antibacterial microcapsules includes the following steps:

[0051] S1 Dissolve 0.3 g of silver nanoparticles and 1.5 g of polylactic acid in 25 mL of dichloromethane, add 0.75 mL of an aqueous solution of polyvinyl alcohol with a concentration of 1.5 wt%, stir at a speed of 800 r / min for 40 min to form an emulsion, and place the emulsion at 2 °C for 12 h to obtain an antibacterial microcapsule emulsion;

[0052] S2 Centrifuge the antibacterial microcapsule emulsion obtained in step S1 at a speed of 8000 r / min for 12 min, collect the antibacterial microcapsule particles, wash them twice with water, and dry them at 45 °C for 12 h to obtain the antibacterial microcapsules.

[0053] Example 2

[0054] A preparation method of a guide wire with a firm hydrophilic coating includes the following steps:

[0055] (1) Dissolve the matrix material in isopropanol, and the concentration of the matrix material is 12 wt%, stir until completely dissolved to obtain a base material solution;

[0056] (2) Add a cross-linking agent to the base material solution obtained in step (1), react at 55 °C for 35 min to obtain a self-healing coating solution;

[0057] (3) Add the antibacterial microcapsules to the self-healing coating solution obtained in step (2) and disperse evenly to obtain a self-healing polymer solution;

[0058] (4) The guide wire is degreased with absolute ethanol and washed with water, and then the self-healing polymer solution obtained in step (3) is coated, with the coating thickness being 40 microns;

[0059] (5) The coated guide wire is placed in an oven and cured at 85 °C for 2 h, and then cooled to room temperature to obtain the guide wire with a firm hydrophilic coating.

[0060] The matrix material in step (1) is composed of polycaprolactam and polycaprolactone mixed in a mass ratio of 70:30.

[0061] The cross-linking agent in step (2) is diphenyl ether.

[0062] The concentration of the antibacterial agent microcapsules in the self-healing polymer solution in step (3) is 3 wt%.

[0063] The preparation method of the antibacterial agent microcapsules includes the following steps:

[0064] S1: 0.3 g of silver nanoparticles and 1.5 g of polylactic acid are dissolved in 25 mL of dichloromethane, 0.75 mL of an aqueous solution of polyvinyl alcohol with a concentration of 1.5 wt% is added, and the mixture is stirred at a speed of 800 r / min for 40 min to form an emulsion. The emulsion is left to stand at 2 °C for 12 h to obtain an antibacterial agent microcapsule emulsion;

[0065] S2: The antibacterial agent microcapsule emulsion obtained in step S1 is centrifuged at a speed of 8000 r / min for 12 min, the antibacterial agent microcapsule particles are collected, washed twice with water, and dried at 45 °C for 12 h to obtain the antibacterial agent microcapsules.

[0066] Example 3

[0067] A preparation method of a guide wire with a firm hydrophilic coating includes the following steps:

[0068] (1) The matrix material is dissolved in isopropanol, with the concentration of the matrix material being 12 wt%, and stirred until completely dissolved to obtain a substrate solution;

[0069] (2) A cross-linking agent is added to the substrate solution obtained in step (1), and the reaction is carried out at 55 °C for 35 min to obtain a self-healing coating solution;

[0070] (3) The antibacterial agent microcapsules are added to the self-healing coating solution obtained in step (2) and uniformly dispersed to obtain a self-healing polymer solution;

[0071] (4) The guide wire is degreased with absolute ethanol and washed with water, and then the self-healing polymer solution obtained in step (3) is coated, with the coating thickness being 40 microns;

[0072] (5) Place the coated guide wire in an oven and cure it at 85 °C for 2 h, then cool it to room temperature to obtain the guide wire with a firm hydrophilic coating.

[0073] The matrix material in step (1) is composed of polycaprolactam and polycaprolactone mixed in a mass ratio of 70:30.

[0074] The cross-linking agent in step (2) is maleic anhydride.

[0075] The concentration of the antibacterial agent microcapsules in the self-healing polymer solution in step (3) is 3 wt%.

[0076] The preparation method of the antibacterial agent microcapsules includes the following steps:

[0077] S1 Dissolve 0.3 g of silver nanoparticles and 1.5 g of polylactic acid in 25 mL of dichloromethane, add 0.75 mL of an aqueous solution of polyvinyl alcohol with a concentration of 1.5 wt%, stir at a speed of 800 r / min for 40 min to form an emulsion, and let the emulsion stand at 2 °C for 12 h to obtain an antibacterial agent microcapsule emulsion;

[0078] S2 Centrifuge the antibacterial agent microcapsule emulsion obtained in step S1 at a speed of 8000 r / min for 12 min, collect the antibacterial agent microcapsule particles, wash them twice with water, and dry them at 45 °C for 12 h to obtain the antibacterial agent microcapsules.

[0079] Example 4

[0080] A preparation method of a guide wire with a firm hydrophilic coating includes the following steps:

[0081] (1) Dissolve the matrix material in isopropyl alcohol, with the concentration of the matrix material being 12 wt%, and stir until completely dissolved to obtain a substrate solution;

[0082] (2) Add a cross-linking agent to the substrate solution obtained in step (1), and react at 55 °C for 35 min to obtain a self-healing coating solution;

[0083] (3) Add an antibacterial agent to the self-healing coating solution obtained in step (2) and disperse it evenly to obtain a self-healing polymer solution;

[0084] (4) Degrease the guide wire with absolute ethanol and wash it with water, then coat it with the self-healing polymer solution obtained in step (3), and the coating thickness is 40 microns;

[0085] (5) Place the coated guide wire in an oven and cure it at 85 °C for 2 h, then cool it to room temperature to obtain the guide wire with a firm hydrophilic coating.

[0086] The matrix material in step (1) is composed of polycaprolactam and polycaprolactone mixed in a mass ratio of 70:30.

[0087] The crosslinking agent described in step (2) is formed by mixing diphenyl ether and maleic anhydride in a mass ratio of 1:1.

[0088] The concentration of the antibacterial agent in the self-healing polymer solution described in step (3) is 3 wt%.

[0089] The antibacterial agent described in step (3) is silver nanoparticles.

[0090] Example 5

[0091] A method for preparing a guide wire with a firm hydrophilic coating, comprising the following steps:

[0092] (1) Dissolve the matrix material in isopropanol, with the concentration of the matrix material being 12 wt%, and stir until completely dissolved to obtain a substrate solution;

[0093] (2) Add a crosslinking agent to the substrate solution obtained in step (1), and react at 55 °C for 35 min to obtain a self-healing coating solution;

[0094] (3) Degrease the guide wire with absolute ethanol and wash it with water, and then coat the self-healing coating solution obtained in step (2), with the coating thickness being 40 microns;

[0095] (4) Place the coated device in an oven, cure it at 85 °C for 2 h, and cool it to room temperature to obtain the guide wire with the firm hydrophilic coating.

[0096] The matrix material described in step (1) is formed by mixing polycaprolactam and polycaprolactone in a mass ratio of 70:30.

[0097] The crosslinking agent described in step (2) is formed by mixing diphenyl ether and maleic anhydride in a mass ratio of 1:1.

[0098] Comparative Example 1

[0099] A method for preparing a guide wire with a firm hydrophilic coating, comprising the following steps:

[0100] (1) Dissolve the matrix material in isopropanol, with the concentration of the matrix material being 12 wt%, and stir until completely dissolved to obtain a substrate solution;

[0101] (2) Add antibacterial agent microcapsules to the substrate solution obtained in step (1) and disperse them evenly to obtain a self-healing polymer solution;

[0102] (3) Degrease the guide wire with absolute ethanol and wash it with water, and then coat the self-healing polymer solution obtained in step (2), with the coating thickness being 40 microns;

[0103] (4) Place the coated device in an oven and cure it at 85 °C for 2 h, then cool it to room temperature to obtain the guide wire with a firm hydrophilic coating.

[0104] The matrix material in step (1) is composed of polycaprolactam and polycaprolactone mixed in a mass ratio of 70:30.

[0105] The concentration of the antimicrobial microcapsules in the self-healing polymer solution in step (2) is 3 wt%.

[0106] The preparation method of the antimicrobial microcapsules includes the following steps:

[0107] S1 Dissolve 0.3 g of silver nanoparticles and 1.5 g of polylactic acid in 25 mL of dichloromethane, add 0.75 mL of an aqueous solution of polyvinyl alcohol with a concentration of 1.5 wt%, stir at a speed of 800 r / min for 40 min to form an emulsion, and place the emulsion at 2 °C for 12 h to obtain an antimicrobial microcapsule emulsion;

[0108] S2 Centrifuge the antimicrobial microcapsule emulsion obtained in step S1 at a speed of 8000 r / min for 12 min, collect the antimicrobial microcapsule particles, wash them twice with water, and dry them at 45 °C for 12 h to obtain the antimicrobial microcapsules.

[0109] Comparative Example 2

[0110] A preparation method of a guide wire with a firm hydrophilic coating includes the following steps:

[0111] (1) Dissolve the matrix material in isopropanol, with the concentration of the matrix material being 12 wt%, and stir until completely dissolved to obtain a substrate solution;

[0112] (2) Add a cross-linking agent to the substrate solution obtained in step (1), and react at 55 °C for 35 min to obtain a self-healing coating solution;

[0113] (3) Add the antimicrobial microcapsules to the self-healing coating solution obtained in step (2) and disperse them evenly to obtain a self-healing polymer solution;

[0114] (4) Degrease the guide wire with absolute ethanol and wash it with water, then coat it with the self-healing polymer solution obtained in step (3), and the coating thickness is 40 microns;

[0115] (5) Place the coated guide wire in an oven and cure it at 85 °C for 2 h, then cool it to room temperature to obtain the guide wire with a firm hydrophilic coating.

[0116] The matrix material in step (1) is composed of polycaprolactam and polyvinyl alcohol mixed in a mass ratio of 70:30.

[0117] The crosslinking agent described in step (2) is formed by mixing diphenyl ether and maleic anhydride in a mass ratio of 1:1.

[0118] The concentration of the antibacterial agent microcapsules in the self-healing polymer solution described in step (3) is 3 wt%.

[0119] The preparation method of the antibacterial agent microcapsules includes the following steps:

[0120] S1 Dissolve 0.3 g of silver nanoparticles and 1.5 g of polylactic acid in 25 mL of dichloromethane, add 0.75 mL of an aqueous solution of polyvinyl alcohol with a concentration of 1.5 wt%, stir at a speed of 800 r / min for 40 min to form an emulsion, and let the emulsion stand at 2 °C for 12 h to obtain an antibacterial agent microcapsule emulsion;

[0121] S2 Centrifuge the antibacterial agent microcapsule emulsion obtained in step S1 at a speed of 8000 r / min for 12 min, collect the antibacterial agent microcapsule particles, wash them twice with water, and dry them at 45 °C for 12 h to obtain the antibacterial agent microcapsules.

[0122] Comparative Example 3

[0123] A preparation method of a guide wire with a firm hydrophilic coating includes the following steps:

[0124] (1) Dissolve the matrix material in isopropanol, with the concentration of the matrix material being 12 wt%, and stir until completely dissolved to obtain a substrate solution;

[0125] (2) Add a crosslinking agent to the substrate solution obtained in step (1), and react at 55 °C for 35 min to obtain a self-healing coating solution;

[0126] (3) Add antibacterial agent microcapsules to the self-healing coating solution obtained in step (2) and disperse them evenly to obtain a self-healing polymer solution;

[0127] (4) Degrease the guide wire with absolute ethanol and wash it with water, and then coat it with the self-healing polymer solution obtained in step (3), with the coating thickness being 40 microns;

[0128] (5) Place the coated guide wire in an oven, cure it at 85 °C for 2 h, and cool it to room temperature to obtain the guide wire with a firm hydrophilic coating.

[0129] The matrix material described in step (1) is polyethylene.

[0130] The crosslinking agent described in step (2) is formed by mixing diphenyl ether and maleic anhydride in a mass ratio of 1:1.

[0131] The concentration of the antibacterial agent microcapsules in the self-healing polymer solution described in step (3) is 3 wt%.

[0132] The preparation method of the antibacterial agent microcapsules comprises the following steps:

[0133] S1 Dissolve 0.3 g of silver nanoparticles and 1.5 g of polylactic acid in 25 mL of dichloromethane, add 0.75 mL of an aqueous solution of polyvinyl alcohol with a concentration of 1.5 wt%, stir at a speed of 800 r / min for 40 min to form an emulsion, and leave the emulsion to stand at 2 °C for 12 h to obtain an antibacterial agent microcapsule emulsion;

[0134] S2 Centrifuge the antibacterial agent microcapsule emulsion obtained in step S1 at a speed of 8000 r / min for 12 min, collect the antibacterial agent microcapsule particles, wash them twice with water, and dry them at 45 °C for 12 h to obtain the antibacterial agent microcapsules.

[0135] Test Example 1

[0136] Antibacterial agent release performance test

[0137] Take the guide wires with a firm hydrophilic coating obtained in Examples 1-4 and Comparative Examples 1-3. The dimensions of the guide wires are: length 2 cm and diameter 1 mm.

[0138] Prepare three solutions:

[0139] Absolute ethanol: used to accelerate the release of the antibacterial agent.

[0140] Simulated body fluid (PBS): pH = 7.4, used to simulate the in-vivo environment and test the release of the antibacterial agent in the coating in the in-vivo environment.

[0141] Normal saline: 0.9% NaCl solution, pH 7.4, used as a control.

[0142] Immerse the samples in 5 ml of absolute ethanol, 5 ml of simulated body fluid, and 5 ml of normal saline respectively.

[0143] The number of samples in each group in each solution is 3 (3 samples in each group to ensure the repeatability and reliability of the experiment).

[0144] Test conditions:

[0145] Immersion temperature: maintained at 37 °C (simulating the in-vivo environment temperature), and constant temperature treatment is carried out using a water bath thermostat.

[0146] Time interval: The immersion time is set to 1 day, and the release of the antibacterial agent is sampled and detected. The concentration of silver nanoparticles in the solution is detected using a UV-Vis spectrometer at a wavelength of 380 nm.

[0147] Table 1 Results of the concentration determination of silver nanoparticles

[0148] Absolute ethanol (mg / L) Simulated body fluid (mg / L) Normal saline (mg / L) Example 1 45 0 0 Example 2 50 4 3 Example 3 52 5 5 Example 4 120 19 19 Comparative Example 1 91 16 15 Comparative Example 2 85 15 15 Comparative Example 3 80 14 13

[0149] Test Example 2

[0150] Self-healing performance test

[0151] Experimental group: The guide wires with a firm hydrophilic coating prepared from Examples 1-3 and Comparative Examples 1-3 after being soaked in absolute ethanol for 1 day in Test Example 1 were treated with 120 °C steam for 6 min, and then placed in 5 ml of simulated body fluid (PBS): pH = 7.4.

[0152] Control group: The guide wires with a firm hydrophilic coating prepared from each example and comparative example after being soaked in absolute ethanol for 1 day in Test Example 1 were directly placed in 5 ml of simulated body fluid (PBS): pH = 7.4.

[0153] Time interval: The soaking time was set to 1 day, and the release of the antibacterial agent was sampled and detected. The concentration of silver nanoparticles in the solution was detected using a UV-Vis spectrometer at a wavelength of 380 nm.

[0154] Table 2 Results of the concentration determination of silver nanoparticles

[0155] Experimental group (mg / L) Control group (mg / L) Example 1 0 24 Example 2 7 28 Example 3 9 31 Comparative Example 1 37 42

[0156] In Test Example 1, in order to verify the controlled release performance of the guide wire coating in different environments, especially the release rate in a specific solvent - absolute ethanol and the release stability in the in vivo simulation environment, so as to ensure that the antibacterial agent will not be released in the physiological environment and only play an antibacterial role under specific conditions. The guide wire with a firm hydrophilic coating prepared in Example 1 can effectively control the release rate of silver nanoparticles in absolute ethanol and achieve the effect of sterilization. In addition, it does not release silver nanoparticles in simulated body fluid and physiological saline, proving its high safety and not causing physiological poisoning caused by the antibacterial agent. Examples 2 and 3 use a single cross-linking agent, and a small amount of silver nanoparticles are released in simulated body fluid and physiological saline, which will have a certain impact on safety. The silver nanoparticle release amount in Example 4 is significantly increased, indicating that the microencapsulation in Example 1 is necessary. Simply relying on the self-healing material cannot effectively control the release rate of silver nanoparticles, resulting in the short-term nature and waste of its effect. Through microcapsule encapsulation, the release of the antibacterial agent can be slower and more continuous. This controlled release characteristic can enable the antibacterial agent to play a role when needed and avoid excessive release when not needed, thereby improving its use efficiency and safety. From the comparison between Comparative Example 1 and Example 1, it can be seen that without using a cross-linking agent in Comparative Example 1, the guide wire coating cannot effectively control the release rate of silver nanoparticles. Comparative Examples 2 and 3 show that the combination of polycaprolactam and polycaprolactone is the best substrate, which can effectively inhibit the release of silver nanoparticles in the human body and control the release rate of silver nanoparticles in absolute ethanol.

[0157] As can be seen from Test Example 2, after the guide wire with a firm hydrophilic coating prepared in Example 1 of the present invention is treated with 120°C water vapor for 6 minutes, it has the best repair effect and can perfectly inhibit the release of silver nanoparticles in simulated body fluid and physiological saline, which is of great significance for the reuse of the prepared guide wire. The combination of these functions ultimately makes the guide wire with a self-repairing coating safer and more efficient in medical applications and has a long-term stable antibacterial effect.

Claims

1. A method for preparing a guide wire having a firm hydrophilic coating, characterized in that: The steps include: (1) dissolving the matrix material in isopropanol at a concentration of 10-15 wt % and stirring until completely dissolved to obtain a matrix solution; (2) adding a crosslinking agent to the substrate solution obtained in step (1), reacting at 50-60° C. for 30-40 minutes to obtain a self-healing coating solution; (3) adding the antibacterial agent microcapsules to the self-healing coating solution obtained in step (2) and uniformly dispersing them to obtain a self-healing polymer solution; (4) treating the guide wire by degreasing with anhydrous ethanol and washing with water, and then coating the guide wire with the self-healing polymer solution obtained in step (3); (5) Placing the coated guide wire in an oven, curing at 80-90° C. for 1-2 hours, and cooling to room temperature to obtain the guide wire with the firm hydrophilic coating.

2. The method for preparing a guide wire having a firm hydrophilic coating as claimed in claim 1, characterized in that: The matrix material in step (1) is prepared by mixing polycaprolactam and polycaprolactone in a mass ratio of (60-80): (20-40).

3. The method for preparing a guide wire having a firm hydrophilic coating as claimed in claim 1, characterized in that: The cross-linking agent in step (2) is prepared by mixing diphenyl ether and maleic anhydride in a mass ratio of (1-2):

1.

4. The method for preparing a guide wire having a firm hydrophilic coating as claimed in claim 1, characterized in that: The concentration of the antibacterial agent microcapsules in the self-repairing polymer solution in step (3) is 2-4wt%.

5. The method for preparing a guide wire having a firm hydrophilic coating as claimed in claim 1, characterized in that: The coating thickness of the guidewire with a firm hydrophilic coating in step (4) is 10-50 microns.

6. The method for preparing a guide wire having a firm hydrophilic coating as claimed in claim 1, characterized in that: The method for preparing the antibacterial agent microcapsules in step (3) comprises the following steps: S1: dissolving 0.1-0.5 g of antibacterial agent and 1-2 g of polylactic acid in 20-30 mL of dichloromethane, adding 0.5-1 mL of polyvinyl alcohol aqueous solution, stirring at 800-1200 r / min for 30-60 min to form an emulsion, and placing the emulsion at 1-4° C. for 12-24 h to obtain an antibacterial agent microcapsule emulsion; S2: centrifuging the antibacterial agent microcapsule emulsion obtained in step S1 at a speed of 5000-10000 r / min for 10-15 min, collecting the antibacterial agent microcapsule particles, washing them with water for 1-2 times, and drying them at 40-50° C. for 8-12 h to obtain the antibacterial agent microcapsules.

7. The method for preparing a guide wire having a firm hydrophilic coating as claimed in claim 6, characterized in that: The antibacterial agent in step S1 is at least one of silver nanoparticles, copper nanoparticles, and natural antibacterial extracts.

8. The method for preparing a guide wire having a firm hydrophilic coating as claimed in claim 6, characterized in that: The concentration of the polyvinyl alcohol aqueous solution is 1-2 wt %.

9. A guide wire with a firm hydrophilic coating, characterized in that: Prepared by the preparation method according to any one of claims 1 to 8.