Nanometer diamond-like film intravascular stent and preparation method thereof

Abstract

The invention relates to the field of medical instruments, in particular to a nano diamond-like film intravascular stent and a preparation method thereof.The preparation method comprises the following steps that firstly, a base material is pretreated, then the nano diamond-like film stent is prepared through a plasma enhanced chemical vapor deposition technology, and after an equipment reaction chamber is adjusted to be in a vacuum state, the nano diamond-like film intravascular stent is prepared under argon protection; the method comprises the following steps: inputting benzene into a vacuum reaction chamber of direct-current arc discharge plasma, introducing silane gas at the same time, bombarding the generated plasma to a negative voltage cathode, and forming a diamond-like carbon film containing a silicon element on the surface when the plasma passes through a substrate material support sample, the silicon element content in the diamond-like carbon film being 15-45%; the silicon element is mainly added to form the elastic concentration gradient type diamond-like carbon film stent, so that the adhesive force, toughness, tensile strength and other physical properties of the coating are improved, the stent has good biocompatibility, and later thrombosis and restenosis after stent implantation are avoided.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, specifically to a nano-diamond-like thin-film vascular stent and its preparation method. Background Technology

[0002] With the aging of society and the Westernization of dietary habits, heart disease is on the rise. For ischemic heart disease, interventional treatment with metallic stents has greatly reduced the physical and financial burden on patients. However, even after dilating narrowed coronary arteries and placing stents, restenosis can occur in 20-30% of cases. Therefore, interventional treatment with drug-eluting stents (DES) has developed rapidly. However, DES implantation still results in 10-20% restenosis and serious delayed thrombosis. In addition, due to the side effects of long-term use of antiplatelet agents, there has been a global trend of returning from DES to bare-metal stents (BMS) without drug coating, but a fundamental solution to the problems of DES has not yet been found.

[0003] To overcome these problems, various coatings have been tried to treat the stent surface and develop stent materials with antithrombotic properties. Among them, diamond-like carbon (DLC) has good biocompatibility and antithrombotic properties, and can be used as a carbon thin film material for stent surface treatment to improve the stent's antithrombotic performance. However, existing DLC ​​stents suffer from problems such as coating cracking or peeling during balloon dilation. Summary of the Invention

[0004] To address the shortcomings of the existing technologies, the present invention aims to provide a nano-diamond-like carbon (DLC) thin-film vascular stent and its preparation method. The present invention primarily employs plasma-enhanced chemical vapor deposition (PECVD) within chemical vapor deposition to prepare the DLC thin-film stent. This technique utilizes a glow discharge process to decompose the reactive gases within the cavity and induce a chemical reaction, thereby achieving the growth of the thin-film material.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0006] The first objective of this invention is to provide a method for preparing a nanodiamond-like thin-film vascular stent, comprising the following steps:

[0007] (1) Substrate material pretreatment: After ultrasonic cleaning and drying, the substrate material is subjected to Ar... + Etching the surface of the material;

[0008] (2) Preparation of nano-diamond-like thin film scaffolds using plasma-enhanced chemical vapor deposition (PECVD): After adjusting the reaction chamber of the equipment to a vacuum state, benzene is introduced into the vacuum reaction chamber of DC arc discharge plasma under argon protection, and silane gas is introduced at the same time. The generated plasma is bombarded to the negative voltage cathode. When the plasma passes through the substrate material scaffold sample, a diamond-like thin film containing silicon is formed on the surface of the substrate material scaffold sample.

[0009] The silicon content in the diamond-like carbon film is 15-45%.

[0010] Preferably, the silicon content in the diamond-like carbon film is 20-30%.

[0011] Preferably, the substrate material is a CoCr-L605 coronary stent.

[0012] Preferably, in step (1), the substrate is washed with acetone solution, anhydrous ethanol and deionized water for 10 minutes each to remove dust and oil from the surface.

[0013] Preferably, the reaction source gas is benzene and silane gas with a purity greater than 99.99%, and the working gas is pure argon with a purity greater than 99.99%.

[0014] Preferably, the coating conditions are: temperature 220–250℃, voltage 1000–1200V, and furnace vacuum degree 1×10⁻⁶. -4 Pa, the time for introducing silane gas is 10 min, and the flow rate is 5-15 mL / min.

[0015] Preferably, all samples were prepared using a self-made plasma-enhanced chemical vapor deposition (PECVD) system.

[0016] Another object of the present invention is to provide a nano-diamond-like thin film vascular stent prepared by any of the above-described preparation methods.

[0017] Preferably, the substrate material has a thickness of 80 μm and a resistivity of 0.001–0.01 Ω·cm. -1 The diamond-like carbon film has a thickness of 10–30 nm and a surface hardness of 20–50 GPa.

[0018] Compared with the prior art, the beneficial effects of the present invention are:

[0019] 1. The diamond-like carbon (DLC) thin film coating of the present invention incorporates silicon content with varying concentrations, exhibiting superior performance compared to conventional DLC coatings due to the formation of numerous graphite structures on the metal surface by SP. 2 The structure has SP with a large number of diamond structures formed on its outer surface. 3The structure is a continuous, layered structure. Therefore, when the support expands, the graphite structure of the carbon coating on the metal surface absorbs the deformation of the metal and does not produce cracks.

[0020] 2. This invention mainly employs plasma-enhanced chemical vapor deposition (PECVD) technology in chemical vapor deposition to develop key technologies for diamond-like carbon (DLC) film-coated stents. It solves the technical bottleneck of DLC films with metal substrates. The main method is to add silicon to form an elastic concentration gradient type DLC carbon film stent, which improves the physical properties of the coating, such as adhesion, toughness, and tensile strength, and gives the stent good biocompatibility, thus avoiding late-stage thrombosis and restenosis after stent implantation.

[0021] 3. This invention optimizes plasma-enhanced chemical vapor deposition (PECVD) technology and proposes a method to change the concentration gradient of silicon content, adding it to a nano-diamond-like carbon film to form a highly elastic concentration gradient type diamond-like thin film coating. This coating can effectively track the deformation of the substrate, preventing the film from cracking or peeling off, and also has excellent adhesion and biocompatibility. Attached Figure Description

[0022] Figure 1 This is a schematic diagram illustrating the principle of the plasma-enhanced chemical vapor deposition equipment of the present invention;

[0023] Figure 2 This is a schematic diagram of the ternary states of the present invention;

[0024] Figure 3 This is a schematic diagram of the four states of the present invention;

[0025] Figure 4 Surface images of diamond-like carbon film scaffolds with silicon contents of 0% and 26.8% prepared according to the present invention;

[0026] Figure 5 This is a comparison of the expanded and deformed films of the nano-diamond-like thin-film vascular stent of the present invention and two competing stents. Detailed Implementation

[0027] The following detailed description, in conjunction with embodiments of the present invention, uses preferred embodiments and accompanying drawings.

[0028] The main equipment used in this invention includes: plasma-enhanced chemical vapor deposition equipment (self-made), electron microscope (TM-1000), vacuum plasma cleaner (TS-PL02), multifunctional material surface performance tester (MFT-4000), microhardness tester (HVS-1000B), laser micro Raman spectrometer (InVia Reflex), atomic force microscope (CSPM5500), etc.

[0029] In this invention, all samples were prepared using a self-made plasma-enhanced chemical vapor deposition (PECVD) apparatus. The apparatus mainly consists of a frame 1, a reactive gas supply system 2, a vacuum system 3, a control system 4, a heated anode 5, a reaction chamber 6, a vascular stent 7, and a water-cooled cathode 8. A schematic diagram of its principle is shown below. Figure 1 As shown.

[0030] Plasma-enhanced chemical vapor deposition (PECVD) technology uses an externally added electric field to act on the gas participating in the reaction within the system, causing the gas to ionize and generate a glow discharge effect. The chemical reaction is activated by high-energy plasma, thus achieving the deposition of the corresponding thin film.

[0031] The deposition principle of this invention utilizes plasma-enhanced chemical vapor deposition (PECVD). Benzene (C6H6) gas, containing the constituent atoms of the thin film, is ionized using radio frequency (RF). Simultaneously, silane gas is introduced, exciting the gas and locally forming plasma. This enhances the chemical activity of the reactive plasma, facilitating the reaction. A CoCr-L605 coronary stent is mounted on a heated anode 5 within the reaction chamber 6. The plasma generated by the ionized gas near the stent surface is activated by cathode sputtering. Following thermochemical and plasma-chemical reactions on the stent surface, the desired nanocrystalline diamond-like carbon film is deposited. This plasma is a mixed aggregate composed of electrons, positive ions, and neutral particles. These particles constantly collide, resulting in energy exchange. Because the mass of ions is much greater than that of electrons, this energy exchange is very slow. Therefore, macroscopically, the internal particle aggregation of the plasma exhibits a thermodynamically equilibrium-like state. However, from a microscopic perspective, the internal particle aggregation of the plasma remains in an excited high-energy state. The high-energy electrons within collide with gas molecules in this field, generating enough energy to break molecular bonds and generate new matter. From an overall perspective, because the reacting gas inside the system is electrically activated into plasma within the reaction chamber, this process generates heat. This avoids the need for external heat to be provided for the reaction, allowing thin films to form on the substrate at relatively low temperatures or even room temperature.

[0032] During the PECVD reaction described above, collisions occur between various particles, especially with high-energy electrons. These high-energy electrons ionize gas molecules, forming a large number of ionized gas ions and many active groups with higher free energy. These active groups with higher free energy undergo complex reactions with other active groups, gas molecules that have not formed active groups, or the groups themselves, developing towards the direction of the active groups required for deposition. The active groups required for deposition, as well as the gas molecules that have not yet been activated, diffuse to the surface of the substrate. After the entire reaction is completed, these gases are directly discharged from the cavity. On the substrate, the active chemical groups generated by the activation process interact with each other, and the reaction products are eventually deposited on the substrate.

[0033] Example 1

[0034] A method for preparing a nanodiamond-like thin-film vascular stent includes the following steps:

[0035] (1) Pretreatment of substrate material

[0036] CoCr-L605 vascular stents (3.0 mm in diameter and 20 mm in length) were selected and ultrasonically cleaned sequentially with acetone, anhydrous ethanol, and deionized water for 10 minutes each to remove surface dust, oil, and other contaminants. After drying, they were placed in a vacuum plasma cleaner (TS-PL02) with argon gas introduced at 60 mL / min, utilizing Ar... + The material surface is etched for 10 minutes to remove the oxide film and other impurities.

[0037] (2) Coating process

[0038] Adjust the equipment reaction chamber to a vacuum (1×10⁻⁶). -4 After reaching the Pa state, at a temperature of 235℃ and a voltage of 1100V, under argon protection, benzene (C6H6) gas was introduced at a flow rate of 20 mL / min into the vacuum reaction chamber of the DC arc discharge plasma. Simultaneously, silane gas was introduced at a flow rate of 10 mL / min. After 10 minutes, the resulting plasma was bombarded by the negative voltage cathode, and a diamond-like carbon coating containing 26.8% silicon was formed on the surface of the stent sample. The advantage of this method is that the ionic hydrocarbons are accelerated by DC bias, hydrogen is ejected from the electrode to form nanoscale gas, and carbon adheres to the surface of the vascular stent to form a diamond-like carbon coating. The hydrocarbons include benzene, acetylene, and silane gases.

[0039] Furthermore, to improve the adhesion of the diamond-like carbon (DLC) film, the silicon content of the scaffold substrate and the DLC coating forms a film with a concentration gradient. This is also to avoid any anomalies at the interface caused by stress concentration due to rapid material changes when bonding with different materials.

[0040] Example 2

[0041] (1) Pretreatment of substrate material

[0042] CoCr-L605 vascular stents (3.0 mm in diameter and 20 mm in length) were selected and ultrasonically cleaned sequentially with acetone, anhydrous ethanol, and deionized water for 10 minutes each to remove surface dust, oil, and other contaminants. After drying, they were placed in a vacuum plasma cleaner (TS-PL02) with argon gas introduced at 60 mL / min, utilizing Ar... + The material surface is etched for 10 minutes to remove the oxide film and other impurities.

[0043] (2) Coating process

[0044] Adjust the equipment reaction chamber to a vacuum (1×10⁻⁶). -4 After reaching the Pa state, the temperature is 235℃ and the voltage is 1100V. Under argon protection, the reaction gas benzene (C6H6) is introduced into the vacuum reaction chamber of DC arc discharge plasma at a flow rate of 20mL / min. At the same time, silane gas is introduced at a flow rate of 5mL / min. After 10min, the plasma generated is bombarded to the negative voltage cathode. When passing through the sample support, a diamond-like coating containing 15% silicon is formed on the surface.

[0045] Example 3

[0046] (1) Pretreatment of substrate material

[0047] CoCr-L605 vascular stents (3.0 mm in diameter and 20 mm in length) were selected and ultrasonically cleaned sequentially with acetone, anhydrous ethanol, and deionized water for 10 minutes each to remove surface dust, oil, and other contaminants. After drying, they were placed in a vacuum plasma cleaner (TS-PL02) with argon gas introduced at 60 mL / min, utilizing Ar... + The material surface is etched for 10 minutes to remove the oxide film and other impurities.

[0048] (2) Coating process

[0049] Adjust the equipment reaction chamber to a vacuum (1×10⁻⁶). -4 After reaching the Pa state, the temperature is 235℃ and the voltage is 1100V. Under argon protection, the reaction gas benzene (C6H6) is introduced into the vacuum reaction chamber of DC arc discharge plasma at a flow rate of 20mL / min. At the same time, silane gas is introduced at a flow rate of 15mL / min. After 10min, the plasma generated is bombarded to the negative voltage cathode. When passing through the sample support, a diamond-like coating containing 45% silicon is formed on the surface.

[0050] Comparative Example 1

[0051] (1) Pretreatment of substrate material

[0052] CoCr-L605 vascular stents (3.0 mm in diameter and 20 mm in length) were selected and ultrasonically cleaned sequentially with acetone, anhydrous ethanol, and deionized water for 10 minutes each to remove surface dust, oil, and other contaminants. After drying, they were placed in a vacuum plasma cleaner (TS-PL02) with argon gas introduced at 60 mL / min, utilizing Ar... + The material surface is etched for 10 minutes to remove the oxide film and other impurities.

[0053] (2) Coating process

[0054] Adjust the equipment reaction chamber to a vacuum (1×10⁻⁶). -4 After reaching the Pa state, the temperature is 235℃ and the voltage is 1100V. Under argon protection, the reaction gas benzene (C6H6) is introduced into the vacuum reaction chamber of DC arc discharge plasma at a flow rate of 20mL / min. No silane gas is introduced, which causes the plasma generated to be bombarded to the negative voltage cathode. When passing through the sample, a diamond-like coating containing 0% silicon is formed on the surface.

[0055] Comparative Example 2

[0056] (1) Pretreatment of substrate material

[0057] CoCr-L605 vascular stents (3.0 mm in diameter and 20 mm in length) were selected and ultrasonically cleaned sequentially with acetone, anhydrous ethanol, and deionized water for 10 minutes each to remove surface dust, oil, and other contaminants. After drying, they were placed in a vacuum plasma cleaner (TS-PL02) with argon gas introduced at 60 mL / min, utilizing Ar... + The material surface is etched for 10 minutes to remove the oxide film and other impurities.

[0058] (2) Coating process

[0059] Adjust the equipment reaction chamber to a vacuum (1×10⁻⁶). -4 After reaching the Pa state, the temperature is 235℃ and the voltage is 1100V. Under argon protection, the flow rate of the reaction gas benzene (C6H6) is 20mL / min, which is input into the vacuum reaction chamber of the DC arc discharge plasma. The flow rate of the introduced silane gas is adjusted, which causes the plasma generated to be bombarded to the negative voltage cathode. When passing through the sample, a diamond-like coating containing 60% silicon is formed on the surface.

[0060] Detection and Analysis

[0061] 1. Structural Analysis of Thin Films

[0062] This invention uses InVia Reflex laser micro-Raman spectroscopy to analyze the structure of the thin film. The characteristic peak of the Raman spectrum of diamond is located at 1332 cm⁻¹. -1 The characteristic peak of the Raman spectrum of single-crystal graphite is located at 1580 cm⁻¹. -1 Diamond-like carbon (DLC) exhibits two Raman activity peaks, located at 1200–1450 cm⁻¹. -1 The D (disorder) mode and located at 1500-1700cm -1 The G (graphite) mode and D mode are circular sp. 2 The vibrational modes of hybrid carbon are generated solely by hexagonal rings; the G mode is the only mode produced by all sp... 2 The stretching vibrations of hybrid carbon are present in all sp... 2 This is caused by the phase. Based on the positions and relative intensities of the D and G peaks, the sp content in the diamond-like carbon film can be qualitatively determined from these changes. 2 / sp 3 The proportion. The Raman spectrometer used in this invention is an In Via type laser spectrometer manufactured by Renishaw, UK. This spectrometer has a laser wavelength of 532 nm and a resolution of 1–2 cm⁻¹. -1 The scanning range is 80–4000 cm. -1 The power is 3mW.

[0063] 2. Morphology analysis of the thin film

[0064] Atomic force microscopy (AFM) has become an important tool for surface analysis in recent years. It is a scanning probe microscope developed based on the basic principle of scanning tunneling microscopy. It can be used to observe the surface morphology of samples, detect surface roughness, and measure instruments.

[0065] The atomic force microscope used in this invention is a CSPM5500 scanning probe microscopy system manufactured by Benyuan Nano Instruments Co., Ltd. It uses a Tap300Al-G scanning probe with an aluminum reflective film coated on the back, a tip curvature radius of 10nm, and an elastic coefficient of 40N / m; the surface morphology of the sample is detected by tapping mode.

[0066] 3. Performance analysis of thin films

[0067] This invention uses a multifunctional material surface performance tester (MFT-4000) and a microhardness tester (HVS-1000B) to test the film thickness, mechanical properties, and friction properties of the thin film.

[0068] (1) Measurement of film thickness

[0069] Film thickness is one of the fundamental parameters of thin films and an important factor affecting film quality. The MFT-4000 multifunctional material surface tester manufactured by Lanzhou Huahui Instrument Technology Co., Ltd. was used to measure film thickness, with a scanning speed of 0.05 mm / s and a scanning range of 5 mm.

[0070] Test results: A biocompatible nanoscale diamond-like thin film coating was applied to the surface of the scaffold, with a coating thickness between 5 and 50 nm, preferably between 10 and 30 nm.

[0071] The film thickness is about 20nm. The film has good thickness and composition uniformity, and the surface is flat, smooth and without ripples. The film layer has strong adhesion. Film thickness is one of the most important technical indicators. If the film thickness is too small, the adhesion will be reduced, and the film will easily detach from the substrate when the stent is expanded by the balloon after implantation. If the film is too thick, the brittleness of the film will increase and the toughness will decrease. Cracks are more likely to occur in the parts of the stent that deform more during expansion.

[0072] (2) Measurement of hardness

[0073] A microhardness tester was selected to evaluate the hardness of the film, using a pyramidal diamond indenter with an α angle of 172.5° and an β angle of 130° between the two top edges. The HVS-1000B digital microhardness tester used in this invention applied a load of 10 gf for 10 seconds during measurement. Four to five points were tested on each sample, and the average value was taken as the composite hardness of the film.

[0074] Test results: When a biocompatible nanoscale diamond-like carbon film coating is applied to the surface of the scaffold, the composite hardness of the DLC film is between 20 and 50 GPa, preferably between 30 and 40 GPa.

[0075] The composite hardness of the film is about 32 GPa. The surface hardness of the film is inversely proportional to its elasticity. When the hardness is too high, the film becomes more brittle, loses elasticity, and has reduced deformation capacity, making it prone to cracking. When the hardness is too low, the film's wear resistance decreases, making it prone to peeling off.

[0076] (3) Measurement of friction coefficient

[0077] Diamond-like carbon (DLC) films have a low coefficient of friction, but due to differences in deposition processes and friction testing conditions, their coefficient of friction varies within a wide range of 0.001 to 0.3. This invention uses an MFT-4000 multifunctional material surface testing instrument manufactured by Lanzhou Huahui Instrument Technology Co., Ltd. to measure the coefficient of friction of DLC films. In the reciprocating friction experiment, the applied load weight was 300g, the selected friction pair material was Si3N4 balls with a diameter of 4mm and a length of 5mm, the speed was 15mm / min, and the time was 15min.

[0078] Test results: When a biocompatible nanoscale diamond-like carbon film coating is applied to the surface of the scaffold, the coefficient of friction of the DLC film is between 0.001 and 0.005.

[0079] The friction coefficient of the membrane is approximately 0.003. After stent implantation, it comes into contact with the inner wall of the blood vessel. If the stent surface is rough, it can easily cause an inflammatory reaction in the intima, leading to intimal thickening and restenosis after stent implantation. Therefore, the lower the friction coefficient of the membrane, the better. Generally, the friction coefficient of the membrane is less than 0.01, and the stent has virtually no effect on the vascular intima after implantation. Therefore, the experimental results meet the requirements for clinical use.

[0080] Experimental Results Analysis

[0081] 1. When the silicon content in diamond-like carbon (DLC) films is 0–15%, the surface hardness value of the film shows a decreasing trend. This is because the low silicon content interferes with carbon atoms, increasing the SP (specified hardness). 2 The proportion of silicon content decreases, thus reducing hardness. When the silicon content in the film exceeds 15%, the surface hardness value tends to increase. This is because C bonds with Si form silicon carbide, which increases the surface hardness of the coating.

[0082] Previous studies have found that as the hydrogen content in diamond-like carbon (DLC) films increases, the number of covalent bonds formed by hydrogen atoms decreases, meaning that the film's hardness decreases with increasing hydrogen content. However, when a DLC film contains silicon, the film's hardness does not entirely depend on the hydrogen content. Figure 2 ).

[0083] 2. The relationship between silicon content and the elastic modulus of diamond-like carbon (DLC) films was obtained using nanoindentation hardness measurement. Increased silicon content led to a decrease in Young's modulus, indicating that the film exhibits elasticity. Generally, higher silicon content results in more polystyrene (SP) in the DLC film. 2 Formation, i.e., SP 2 / SP 3 The increased proportion of [a specific component] will drive the graphitization process, thus a lower Young's modulus will give the film better elasticity. Figure 3 ).

[0084] The silicon content in the diamond-like carbon film is 15-45%, preferably 20-30%.

[0085] 3. Two types of diamond-like carbon (DLC) film coating scaffolds were prepared: one with a high Young's modulus (0% silicon content) and the other with a gradient silicon concentration (26.8% silicon content), i.e., a DLC film scaffold with a lower Young's modulus. The scaffold diameter was expanded from 1.5 mm to 3.0 mm using a balloon. Electron microscopy (TM-1000) was used to observe the area of ​​maximum strain. Cracks were found on the surface of the 0% silicon nanocoating scaffold, but no cracks appeared on the surface of the 26.8% silicon concentration gradient film scaffold, indicating that the silicon nanocoating has superior adhesion. Figure 4 ).

[0086] 4. To further verify the adhesion performance of a concentration-gradient diamond-like carbon (DLC) film with a silicon content of 26.8%, a scaffold with a nominal diameter of 3.0 mm was expanded to 4.0 mm using a balloon, and the location of maximum strain was observed using an electron microscope (TM-1000). For ease of analysis and comparison, two types of DLC film scaffolds currently used clinically were compared under the same conditions, and the location of maximum strain was observed. Figure 5 These are electron microscope images of the expanded scaffold. Figure (a) shows the surface condition of the coating of the concentration gradient thin film scaffold with a silicon content of 26.8% of the present invention without cracks or peeling. Figures (b) and (c) show the surface condition of the coating at the point of maximum deformation of two competing scaffolds under the same conditions, where micro-cracks have occurred.

[0087] 5. The DLC nanocoating has been proven to be inert to organisms in in vitro and in vivo blood compatibility tests, and can be further applied to the surface coating of interventional medical devices such as left atrial appendage occluders, vena cava filters, artificial heart valves, and artificial hearts.

[0088] The above experimental results demonstrate that the nano-diamond-like carbon film coating of this invention has superior adhesion compared to other products.

[0089] In summary, this invention optimizes plasma-enhanced chemical vapor deposition (PECVD) technology and proposes a method to change the concentration gradient of silicon content to incorporate it into a nano-diamond-like carbon film, forming a highly elastic concentration gradient diamond-like carbon film coating. This coating can effectively track the deformation of the substrate, preventing the film from cracking or peeling off, and also exhibits excellent adhesion and biocompatibility.

[0090] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A method for preparing a nanodiamond-like thin-film vascular stent, characterized in that, Includes the following steps: (1) Substrate material pretreatment: After ultrasonic cleaning and drying, the substrate material is subjected to Ar... + Etch the material surface for 10 minutes; (2) Preparation of nano-diamond-like thin film scaffolds using plasma-enhanced chemical vapor deposition technology: After adjusting the reaction chamber of the equipment to a vacuum state, benzene is input into the vacuum reaction chamber of DC arc discharge plasma under argon protection, and silane gas is introduced at the same time. The generated plasma is bombarded to the negative voltage cathode. When the plasma passes through the substrate material scaffold sample, a diamond-like thin film containing silicon is formed on the surface of the substrate material scaffold sample. The silicon content in the diamond-like carbon film is 15-45%.

2. The method for preparing a nano-diamond-like thin-film vascular stent according to claim 1, characterized in that, The silicon content in the diamond-like carbon film is 20-30%.

3. The method for preparing a nano-diamond-like thin-film vascular stent according to claim 1, characterized in that, The substrate material is a CoCr-L605 coronary stent.

4. The method for preparing a nano-diamond-like thin-film vascular stent according to claim 1, characterized in that, Step (1) Clean the substrate sequentially with acetone solution, anhydrous ethanol and deionized water for 10 minutes each to remove dust and oil stains from the surface.

5. The method for preparing a nano-diamond-like thin-film vascular stent according to claim 1, characterized in that, The purity of benzene, silane gas, and argon gas is greater than 99.99%.

6. The method for preparing a nano-diamond-like thin-film vascular stent according to claim 1, characterized in that, The coating conditions are: temperature 220–250℃, voltage 1000–1200V, and furnace vacuum of 1×10⁻⁶. -4 Pa, the time for introducing silane gas is 10 min, and the flow rate is 5-15 mL / min.

7. The method for preparing a nano-diamond-like thin-film vascular stent according to claim 1, characterized in that, All samples were prepared using a self-made plasma-enhanced chemical vapor deposition (PECVD) system.

8. A nano-diamond-like thin-film vascular stent prepared by any one of the preparation methods described in claims 1-7.

9. The nano-diamond-like thin-film vascular stent according to claim 8, characterized in that, The substrate material has a thickness of 80 μm and a resistivity of 0.001–0.01 Ω·cm. -1 The diamond-like carbon film has a thickness of 10–30 nm and a surface hardness of 20–50 GPa.

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