Hydrophilic coating for interventional medical instrument, and preparation method therefor

Abstract

A hydrophilic coating for an interventional medical instrument, and a preparation method therefor. The preparation method comprises: providing a base material for forming an interventional medical instrument; using a plasma inert gas to treat the base material; dropwise adding a silane coupling agent around the base material; sublimating and cracking octafluoro[2,2]paracyclophane used as a deposition source material and then carrying out chemical vapor deposition on the base material to form a deposition coating, wherein the sublimation temperature is 145-155°C, the cracking temperature is 680°C, and the thickness of the deposition coating is 4-6 μm; and carrying out oxygen plasma surface treatment on the deposited coating for 10-15 min, thereby obtaining a hydrophilic surface coating. By means of physical and chemical double modification, the present invention improvs the bonding performance and the hydrophilic lubricating performance of the coating. The hydrophilic surface coating of the present invention can be applied to various interventional medical instruments.

Description

Hydrophilic coating for interventional medical devices and preparation method thereof Technical Field

[0001] The present invention generally relates to a surface modification coating for an interventional medical device. Background Art

[0002] Interventional diagnostic and treatment technologies, as a key component of minimally invasive cardiovascular surgery, are becoming increasingly widespread. A wide variety of catheters, guidewires, and balloons, common medical devices used in interventional procedures, are constantly being developed. These interventional devices are typically made of materials or surface finishes such as polyurethane, silicone rubber, and stainless steel. While these materials offer certain blood compatibility and safety, they lack inherent lubricity. Excessive friction during interventional procedures can even cause vascular damage. Therefore, lubrication modification of the surfaces of these interventional medical devices is essential.

[0003] Surface lubricity modification for interventional devices is typically achieved through thermal or photocuring, as described in CN109966560B, CN107641412B, and CN102727945A. Thermal curing typically requires a long heating period, resulting in low efficiency. While photocuring offers some convenience, it requires multiple coatings and treatments, reducing production efficiency.

[0004] Furthermore, during the delivery of interventional devices into blood vessels, they are not only subject to erosion and erosion by blood but also to repeated friction with internal tissues. Therefore, the adhesion and wear resistance of the coating are also key factors that cannot be ignored. Simple hydrophilic modification methods make it difficult to achieve good and long-term adhesion on the surface of interventional devices, thus easily causing them to fall off.

[0005] Summary of the Invention

[0006] An object of the present invention is to provide a hydrophilic coating for an interventional medical device, which has at least better lubricity and bonding performance with a substrate.

[0007] According to a first aspect of the present invention, there is provided a method for preparing a hydrophilic surface coating for an interventional medical device, comprising:

[0008] Providing a base material for forming an interventional medical device;

[0009] cleaning the substrate material, including treating the substrate material with a plasma inert gas;

[0010] providing a deposition source material comprising octafluoro[2,2]diparylene;

[0011] Provide silane coupling agent A-1170;

[0012] Adding silane coupling agent A-1170 dropwise around the base material;

[0013] chemically vapor depositing the deposition source material onto the base material to form a deposition coating; and

[0014] The deposited coating is subjected to oxygen plasma surface treatment for 10 to 15 minutes to obtain a hydrophilic surface coating.

[0015] The deposition source material is deposited on the base material after being sublimated and cracked, wherein the sublimation temperature is 145°C to 155°C, the cracking temperature is 680°C, and the thickness of the deposited coating is 4 to 6 microns.

[0016] According to the present invention, the base material is typically a metal, such as stainless steel.

[0017] According to the present invention, the sublimation temperature is preferably about 150° C. In addition, the thickness of the deposited coating is preferably set to about 5 μm.

[0018] According to the present invention, the substrate material may be treated with a plasma inert gas, such as nitrogen or argon. This plasma gas treatment not only further cleans the substrate material but also enhances the surface activity of the substrate material, thereby making it more conducive to subsequent chemical vapor deposition coatings and further enhancing the coating bonding ability.

[0019] According to the present invention, the use of a silane coupling agent can further enhance the bonding strength between the coating and the metal base material, making the coating more secure.

[0020] According to another aspect of the present invention, an interventional medical device is provided, which is made of a metal base material, and a hydrophilic surface coating obtained according to the above preparation method is formed on the metal base material.

[0021] The present invention obtains a deposited coating with good coating bonding ability and excellent biological properties through an optimized chemical vapor deposition process, ensuring that the coating of interventional medical devices will not crack or fall off due to deformation and bending of the device in various complex situations during the surgical process, thereby ensuring the safety and biocompatibility of the device.

[0022] The hydrophilic surface coating of the interventional device prepared according to the present invention is prepared by physical and chemical insertion of oxygen plasma in parallel. On the one hand, impurities are removed from the surface of the interventional device. On the other hand, the oxygen plasma induces the formation of hydrophilic groups such as hydroxyl and carboxyl groups on the surface, so that the surface of the interventional device has good cleanliness and excellent hydrophilic properties (significantly reducing the water contact angle of the coating surface).

[0023] The hydrophilic surface coating of the present invention is modified through both physical and chemical means, avoiding the damage to human tissue caused by residual organic solvents after curing in existing aqueous systems. It also effectively reduces safety risks posed to operators during the production process. The hydrophilic surface coating of the present invention is highly adaptable and particularly suitable for interventional medical devices such as guidewires, guiding catheters, balloon catheters, peripheral intravenous catheters, microcatheters, and vascular sheaths, which are common in minimally invasive cardiovascular interventional diagnosis and treatment. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] FIG1 is a Raman spectrum of the corresponding deposited coatings obtained in Comparative Examples 1-6 of the present invention;

[0025] FIG2 is a SEM image of the surface morphology of the corresponding deposited coatings obtained in Comparative Examples 1-6 according to the present invention;

[0026] FIG3 is an AFM image of the three-dimensional morphology of the corresponding deposited coatings obtained in Comparative Examples 1-6 of the present invention;

[0027] FIG4 is a diagram showing the water contact angle ranking of corresponding deposited coatings obtained in Comparative Examples 1-6 according to the present invention;

[0028] FIG5 is a graph showing the water contact angles of the corresponding deposited coatings obtained in Comparative Examples 1-6 according to the present invention;

[0029] FIG6 is a graph showing the water contact angle of the hydrophilic surface coating obtained in Comparative Example 7 according to the present invention;

[0030] FIG7 is a graph showing the water contact angle of a hydrophilic surface coating obtained according to an embodiment of the present invention. DETAILED DESCRIPTION

[0031] The present invention will be further described below with reference to the accompanying drawings and specific examples.

[0032] In the following comparative examples and examples, the composition and structure of the coatings were analyzed using a LabRAM HR Evolution laser Raman spectrometer from HORIBA FRANCE, France;

[0033] The micromorphology and thickness of the coating were analyzed using a JSM-IT500HR field emission environmental scanning electron microscope (SEM) equipped with an energy dispersive spectrometer (EDS) from JSM Co., Ltd., Japan.

[0034] The three-dimensional morphology and surface relief of the coatings were analyzed using a Dimension XR scanning probe atomic force microscope (AFM) from Bruker, USA;

[0035] The water contact angle of the coating was measured using a JC2000C1 contact angle meter produced by Shanghai Zhongchen Digital Technology Equipment Co., Ltd.

[0036] The base material of the interventional medical device is 316L stainless steel sheet with a length of 20 mm, a width of 20 mm and a thickness of 1 mm.

[0037] Comparative Example 1: The substrate material was placed in a beaker containing 100 mL of acetone and ultrasonically cleaned for 10 minutes at a power of 90 W.

[0038] After drying the substrate, place it in a plasma chamber, introduce nitrogen, set the power to 300W, and treat with plasma gas for 10 minutes.

[0039] Place the treated substrate material into the chemical vapor deposition chamber and drip 0.2 mL of silane coupling agent (Maitu A-1170) around the substrate material;

[0040] Octafluoro[2,2]diphenylene as a deposition source was sublimated into gas in a sublimation chamber at a sublimation temperature of 150°C.

[0041] The sublimated gas is then introduced into the cracking chamber to be cracked into cracking gas containing active monomer free radicals at a cracking temperature of 650°C.

[0042] The cracking gas was introduced into the deposition chamber and deposited on the substrate material to obtain a deposition coating. The deposition pressure was 5 Pa, the background vacuum of the deposition chamber was 13 mT, the deposition temperature was set to 25° C., and the coating thickness was set to 5 μm.

[0043] Comparative Examples 2-6: The cracking temperatures in step (3) were set to 660°C, 670°C, 680°C, 690°C, and 700°C, respectively; the rest were the same as in Comparative Example 1.

[0044] Comparative Example 7: The substrate material deposited with the deposited coating obtained in Comparative Example 4 (pyrolysis temperature 680°C) was further placed in a plasma chamber, oxygen was introduced, the power was set to 50W, and the corresponding hydrophilic surface coating was obtained after oxygen plasma gas surface treatment for 5 minutes.

[0045] Example: Oxygen plasma gas surface treatment for 10 minutes; other conditions are the same as those of Comparative Example 7. The Raman spectra of the corresponding deposited coatings obtained in Comparative Examples 1-6 were measured, and the results are shown in Figure 1. As can be seen from Figure 1, the Raman spectra of the deposited coatings at different temperatures have similar shapes, especially for the three typical characteristic peak positions of the parylene-based deposited coatings, 1000 cm -1 aliphatic C—C bond, 1348 cm -1 CF bond at 1665cm -1 This indicates that the parylene-based deposited coating was successfully coated on the substrate surface.

[0046] The surface morphology SEM images of the corresponding deposited coatings obtained in Comparative Examples 1-6 were measured, as shown in Figure 2. It can be seen that the surface of the coating with a cracking temperature of 650°C is uniform and dense, but there is wrinkling on the coating, which is caused by the difference in the elastic modulus of the surface. When the temperature rises, the surface of the coating also shows greater wrinkling to varying degrees. This shows to a certain extent that increasing the cracking temperature strengthens the molecular movement, resulting in certain differences in the surface morphology and coating performance after the coating is formed, which also makes the coating have good anti-adhesion ability. However, it should be noted that under the condition of a cracking temperature of 680°C, the wrinkling on the coating surface is alleviated, the surface is flat and uniform, and the surface quality is significantly better than the comparative examples corresponding to other cracking temperatures.

[0047] The three-dimensional morphology AFM images of the corresponding deposited coatings obtained in Comparative Examples 1-6 were measured, as shown in Figure 3. It can be seen that the coating has a certain degree of undulation at each temperature, and the three-dimensional morphology shows that the range of surface undulations at different temperatures is at the nanometer level. However, when the pyrolysis temperature is 690°C and 700°C, the surface undulation of the coating is significantly greater than 150nm, far exceeding that of the coatings at other pyrolysis temperatures. However, the coating obtained at a pyrolysis temperature of 680°C not only has relatively good surface flatness, but also has smaller surface undulations than other pyrolysis temperatures. Combined with the three-dimensional morphology analysis of scanning electron microscopy and atomic force microscopy, it can be seen that the coatings prepared under various temperature conditions are dense and uniform, without surface cracking, and the surface has certain undulations.

[0048] The surface water contact angles of the corresponding deposited coatings obtained in Comparative Examples 1-6 were measured respectively. FIG4 is a ranking diagram thereof, and FIG5 is a measurement diagram thereof.

[0049] When the cracking temperature increases from 650℃ to 700℃, the water contact angle of the coating shows a trend of first increasing and then decreasing. This is because as the temperature rises, the energy of the dimer monomer gas molecules of the deposited coating becomes higher and higher, which leads to differences in the performance of the coating formed after polymerization. At the same time, too high a temperature will cause the dimer monomer to over-crackle and have higher energy, which in turn reduces the performance of the coating. Therefore, the increase in cracking temperature has a certain limit, that is, at 680℃, the performance of the coating itself is the best among all cracking temperatures. On this basis, further increasing the cracking temperature will lead to a decrease in the lubrication performance of the coating.

[0050] Water contact angle measurements were performed on the hydrophilic surface coatings obtained in Comparative Example 7 and the Example after oxygen plasma modification for different periods of time. Figure 6 shows the water contact angle measurements for the hydrophilic surface coating obtained in Comparative Example 7; Figure 7 shows the water contact angle measurements for the hydrophilic surface coating obtained in the Example. Comparison of Figures 4-7 reveals that the unmodified coating obtained in Comparative Example 4 exhibits overall hydrophobicity, with a water contact angle of 93.4°. However, the coatings obtained in Comparative Example 7 and the Example after oxygen plasma modification both exhibit excellent hydrophilicity, with water contact angles of 14.479° and 2.045°, respectively. Compared to the hydrophilic surface coating obtained in Comparative Example 7, the hydrophilic surface coating obtained in the Example exhibits significantly lower water contact angles, even exhibiting superhydrophilicity.

Claims

1. A method for preparing a hydrophilic surface coating for an interventional medical device, comprising: Providing a matrix material for forming an interventional medical device; cleaning the substrate material, including treating the substrate material with a plasma inert gas; providing a deposition source material comprising octafluoro[2,2]diparylene; Provide silane coupling agent A-1170; Add silane coupling agent A-1170 dropwise around the base material; Chemically vapor depositing the deposition source material on the base material to form a deposition coating; as well as The deposited coating is subjected to oxygen plasma surface treatment for 10 to 15 minutes to obtain a hydrophilic surface coating. The deposition source material is deposited on the base material after being sublimated and cracked, wherein the sublimation temperature is 145°C to 155°C, the cracking temperature is 680°C, and the thickness of the deposition coating is 4 to 6 microns.

2. The preparation method according to claim 1, wherein the matrix material is metal.

3. An interventional medical device, made of a metal matrix material, wherein the metal matrix material is formed A hydrophilic surface coating obtained according to the preparation method of claim 1.

Images