An antimicrobial coating for medical device surfaces

Abstract

The present application belongs to the technical field of medical instrument surface coating, and relates to an antibacterial coating for the surface of a medical instrument, comprising copper oxide, cuprous oxide and polytetrafluoroethylene; wherein the molar ratio of copper oxide to cuprous oxide is 1:1 to 3:1, and the molar ratio of the total moles of copper oxide and cuprous oxide to polytetrafluoroethylene is 1:1.5 to 1:3; the coating is formed by a magnetron co-sputtering process, and the copper oxide, cuprous oxide and polytetrafluoroethylene exist in a nanoscale interwoven and uniformly dispersed composite state in the coating. To some extent, the technical problems of low hardness, easy wear and tear, and difficulty in balancing hydrophobicity and antibacterial performance of the coating in the prior art are solved.

Description

Technical Field

[0001] This invention belongs to the field of medical device surface coating technology, and particularly relates to an antibacterial coating for the surface of medical devices. Background Technology

[0002] Medical devices, especially surgical instruments, implants, and endoscopes that frequently come into contact with human tissues and fluids, have surface properties that directly affect the safety and effectiveness of their clinical use. During clinical use, these devices are prone to the adhesion of biological contaminants such as blood, proteins, and microorganisms, forming biofilms. This not only causes corrosion and reduces the lifespan of the devices but also serves as a carrier for the growth and spread of pathogenic microorganisms. Therefore, functional modification of medical device surfaces to endow them with durable antibacterial capabilities is an important research direction in the field of medical devices.

[0003] To impart antibacterial properties to the surface of medical devices, the main technical approach is to construct an antibacterial coating on its surface. However, existing antibacterial coatings face a significant contradiction in practical applications: the simultaneous fulfillment of three properties—hardness, hydrophobicity, and bactericidal activity—is difficult. While single hydrophobic coatings (such as polytetrafluoroethylene coatings) can effectively repel bodily fluids, they suffer from low hardness and lack active bactericidal function. Single antibacterial coatings (such as coatings made of silver, copper, zinc, or their oxides) possess antibacterial properties, but their surfaces are often hydrophilic with poor hydrophobicity, failing to effectively prevent the initial adhesion of bodily fluids and microorganisms. Furthermore, their bactericidal performance may diminish due to excessive or rapid ion release. Although some studies have attempted to prepare polytetrafluoroethylene-metal oxide composite coatings, these generally suffer from insufficient hardness and poor synergy between hydrophobic and bactericidal properties, leading to easy wear and peeling of the coating during the clamping, friction, or cleaning and disinfection of medical devices.

[0004] Therefore, there is an urgent need for a new type of antibacterial coating for the surface of medical devices. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides an antibacterial coating for the surface of medical devices, which to some extent solves the technical problems of low coating hardness, easy wear and peeling, and difficulty in achieving both hydrophobicity and antibacterial properties in existing technologies.

[0006] To achieve the above objectives, the main technical solutions adopted by the present invention include:

[0007] This invention provides an antibacterial coating for the surface of medical devices, comprising copper oxide, cuprous oxide and polytetrafluoroethylene; wherein the molar ratio of copper oxide to cuprous oxide is 1:1 to 3:1, and the molar ratio of the total number of copper oxide and cuprous oxide to polytetrafluoroethylene is 1:1.5 to 1:3; the coating is formed by magnetron co-sputtering, and the copper oxide, cuprous oxide and polytetrafluoroethylene exist in a composite state in which they are interwoven and uniformly dispersed at the nanoscale in the coating.

[0008] Optionally, the thickness of the antibacterial coating is 0.5-5 μm.

[0009] Optionally, the antibacterial coating is used to cover a medical device substrate that has undergone high-energy nitrogen ion beam surface modification treatment. The surface of the substrate has a micro-nano rough structure with a roughness Ra of 0.1-0.5 μm and a size of 50-500 nm for the micro-nano protrusions.

[0010] Optionally, the antibacterial coating is prepared by a method comprising the following steps: placing a pretreated medical device substrate in a magnetron sputtering device equipped with an ion beam source, and subjecting the substrate surface to high-energy nitrogen ion beam irradiation to form a micro-nano rough structure on the substrate surface; depositing an antibacterial coating on the substrate surface with the micro-nano rough structure by co-sputtering; wherein the sputtering target is a cuprous oxide target and a polytetrafluoroethylene target, and the deposition process is carried out at room temperature.

[0011] Optionally, the sputtering environment is evacuated to a vacuum level ≤5×10⁻⁶. -3 A nitrogen gas was introduced as the ion source to irradiate the substrate surface with a high-energy nitrogen ion beam. The parameters for the high-energy nitrogen ion beam irradiation included: accelerating voltage of 10-30 keV and beam current density of 0.5-2 mA / cm². 2 The irradiation time is 5-20 minutes, and the nitrogen flow rate is 10-30 sccm.

[0012] Optionally, argon gas is introduced into the sputtering environment, and the coating pressure is controlled at 0.1-0.3 Pa. Then, an antibacterial coating is deposited on the substrate surface by co-sputtering. The co-sputtering parameters include: a power density of 2-5 W / cm² for the cuprous oxide target. 2 The power density of the polytetrafluoroethylene target is 1-3 W / cm². 2 Sputtering time: 20-60 min.

[0013] Optionally, the molar ratio of copper oxide to cuprous oxide in the antibacterial coating can be adjusted by controlling whether oxygen is introduced into the sputtering environment and the flow rate of oxygen.

[0014] Optionally, when oxygen is introduced into the sputtering environment, the oxygen flow rate is 5-15 sccm.

[0015] Optionally, during the co-sputtering deposition process, a bias voltage is applied to the substrate, with the bias voltage ranging from -50V to -200V and the frequency from 10 to 50kHz.

[0016] The beneficial effects of this invention are:

[0017] The antibacterial coating provided by this invention offers several advantages. Firstly, the composite of copper oxide and cuprous oxide provides highly efficient and controllable antibacterial capabilities. When the molar ratio of copper oxide to cuprous oxide is close to 1:1, it emphasizes instantaneous sterilization and a balance of overall performance. When the molar ratio is close to 3:1, it emphasizes long-lasting sterilization and improved coating hardness. By adjusting the molar ratio of copper oxide to cuprous oxide, it can be flexibly adapted to the needs of different medical devices. Secondly, the introduction of polytetrafluoroethylene (PTFE) and the adjustment of the total molar ratio of copper oxide and cuprous oxide to PTFE to 1:1.5 to 1:3 endow the coating with excellent hydrophobicity while simultaneously maintaining both hydrophobicity and antibacterial properties, effectively reducing the adhesion of body fluids and initial adhesion of microorganisms. Furthermore, the nanocomposite effect achieved through magnetron co-sputtering allows for a tight microscopic bond between the high-hardness metal oxide and the tough PTFE, significantly improving the coating's hardness, wear resistance, and adhesion to the medical device substrate while maintaining excellent hydrophobicity and antibacterial properties. The antibacterial coating provided by this invention solves, to a certain extent, the key defects of the prior art, such as low coating hardness, easy wear and peeling, and difficulty in achieving both hydrophobicity and antibacterial properties, enabling the coating to adapt to long-term use in complex clinical environments. Attached Figure Description

[0018] The present invention is described with reference to the following figures:

[0019] Figure 1 This is a schematic diagram of the coating contact angle in Example 1;

[0020] Figure 2 This is a schematic diagram of the coating contact angle in Example 2;

[0021] Figure 3 This is a schematic diagram of the coating contact angle in Example 3;

[0022] Figure 4 This is a schematic diagram of the coating contact angle in Example 4. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] Unless otherwise defined, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains; the terminology used in the specification of this application is for the purpose of describing particular embodiments only and is not intended to limit the invention; the terms "comprising" and "having," and any variations thereof, in the specification, claims, and foregoing drawings are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the specification, claims, or foregoing drawings are used to distinguish different objects, not to describe a particular order or hierarchy.

[0025] In this invention, the reference to "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the invention. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments.

[0026] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "attachment" should be interpreted broadly. For example, they can refer to direct connection or indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0027] In this invention, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, in this invention, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0028] In the embodiments of the present invention, the same reference numerals denote the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width, and other dimensions of various components in the embodiments of the present invention shown in the accompanying drawings, as well as the overall thickness, length, width, and other dimensions of the integrated device, are merely illustrative and should not constitute any limitation on the present invention.

[0029] In this invention, "multiple" refers to two or more, including two.

[0030] This invention provides an antibacterial coating for the surface of medical devices, comprising copper oxide, cuprous oxide, and polytetrafluoroethylene (PTFE); wherein the molar ratio of copper oxide to cuprous oxide is 1:1 to 3:1, and the molar ratio of the total molar number of copper oxide and cuprous oxide to PTFE is 1:1.5 to 1:3. The coating is formed by magnetron co-sputtering, and the copper oxide, cuprous oxide, and PTFE exist in a composite state of nanoscale interweaving and uniform dispersion within the coating.

[0031] The antibacterial coating provided by this invention offers several advantages. Firstly, the composite of copper oxide and cuprous oxide provides highly efficient and controllable antibacterial capabilities. When the molar ratio of copper oxide to cuprous oxide is close to 1:1, it emphasizes instantaneous sterilization and a balance of overall performance. When the molar ratio is close to 3:1, it emphasizes long-lasting sterilization and improved coating hardness. By adjusting the molar ratio of copper oxide to cuprous oxide, it can be flexibly adapted to the needs of different medical devices. Secondly, the introduction of polytetrafluoroethylene (PTFE) and the adjustment of the total molar ratio of copper oxide and cuprous oxide to PTFE to 1:1.5 to 1:3 endow the coating with excellent hydrophobicity while simultaneously maintaining both hydrophobicity and antibacterial properties, effectively reducing the adhesion of body fluids and initial adhesion of microorganisms. Furthermore, the nanocomposite effect achieved through magnetron co-sputtering allows for a tight microscopic bond between the high-hardness metal oxide and the tough PTFE, significantly improving the coating's hardness, wear resistance, and adhesion to the medical device substrate while maintaining excellent hydrophobicity and antibacterial properties. The antibacterial coating provided by this invention solves, to a certain extent, the key defects of the prior art, such as low coating hardness, easy wear and peeling, and difficulty in achieving both hydrophobicity and antibacterial properties, enabling the coating to adapt to long-term use in complex clinical environments.

[0032] It should be noted that the key to this invention's selection of a specific combination of copper oxide, cuprous oxide, and polytetrafluoroethylene lies in: 1. The nanoscale interwoven composite structure formed within the aforementioned specific ratio range synergistically achieves a comprehensive performance of high hardness, high hydrophobicity, efficient antibacterial properties, and excellent adhesion. 2. Utilizing the two stable oxidation states of copper (+1 and +2), by adjusting the molar ratio of copper oxide to cuprous oxide in the coating, the bactericidal performance and hardness can be regulated, thereby adapting to the needs of different medical devices.

[0033] Preferably, the thickness of the antibacterial coating is 0.5-5 μm. This ensures that the coating provides sufficient antibacterial, hydrophobic, and mechanical protection while avoiding the possibility that excessive thickness may affect the functionality of the device or that insufficient thickness may result in inadequate coating performance.

[0034] Preferably, the antibacterial coating is applied to a medical device substrate that has undergone surface modification treatment with a high-energy nitrogen ion beam. The surface of the substrate has a micro / nano rough structure with a roughness Ra of 0.1-0.5 μm and a size of 50-500 nm for the micro / nano protrusions. Applying the antibacterial coating to the medical device substrate after high-energy nitrogen ion beam surface modification significantly increases the actual contact area and mechanical interlocking effect between the coating and the substrate, thereby greatly enhancing the adhesion between the coating and the substrate and effectively preventing it from detaching under mechanical stresses such as friction and cleaning.

[0035] More preferably, the antibacterial coating provided by the present invention is prepared by a method comprising the following steps: placing a pretreated medical device substrate in a magnetron sputtering device equipped with an ion beam source, and subjecting the substrate surface to high-energy nitrogen ion beam irradiation treatment to form a micro-nano rough structure on the substrate surface; and depositing the antibacterial coating on the substrate surface with the micro-nano rough structure by co-sputtering. The sputtering targets are cuprous oxide and polytetrafluoroethylene (PTFE) targets, and the deposition process is carried out at room temperature. Thus, high-energy nitrogen ion beam irradiation and magnetron co-sputtering deposition are integrated into the same device for continuous processing, achieving integrated processing without the need to transfer the substrate between different devices, greatly simplifying the production process, reducing the risk of secondary contamination due to exposure and transfer, and significantly improving production efficiency and coating consistency. Secondly, the deposition process is carried out entirely at room temperature, effectively avoiding the damage to the PTFE molecular chain structure and hydrophobic properties caused by high temperatures, ensuring the stability of the coating's core functions. Furthermore, no annealing treatment is required; after sputtering, the medical device is cooled to room temperature to obtain a medical device with an antibacterial coating.

[0036] Specifically, before placing the medical device substrate in the magnetron sputtering equipment, a pretreatment step for the medical device substrate is also included. The pretreatment step includes: mechanically grinding, degreasing, derusting, cleaning and drying the medical device substrate in sequence to remove impurities, oxide layers and oil stains on the substrate surface, so as to obtain a clean and smooth substrate, thereby laying the foundation for subsequent ion beam modification and coating deposition.

[0037] Specifically, the pretreated medical device substrate is placed in a magnetron sputtering apparatus equipped with an ion beam source. Both the cuprous oxide and polytetrafluoroethylene (PTFE) targets are connected to an RF power supply, while the substrate is connected to a bias power supply. First, the substrate undergoes high-energy nitrogen ion beam surface modification, followed by magnetron co-sputtering deposition of a composite coating on the substrate surface. In this way, the substrate is connected to a bias power supply, which, through ion assistance during the deposition process, further enhances the energy and density of the coating particles, improving the adhesion between the coating and the substrate.

[0038] Preferably, the sputtering environment is evacuated to a vacuum level ≤ 5 × 10⁻⁶. -3 A nitrogen gas was introduced as the ion source to irradiate the substrate surface with a high-energy nitrogen ion beam. The parameters for the high-energy nitrogen ion beam irradiation included: accelerating voltage of 10-30 keV and beam current density of 0.5-2 mA / cm². 2 The irradiation time is 5-20 min, and the nitrogen flow rate is 10-30 sccm. Setting these parameters for the accelerating voltage and beam current density ensures that the ion beam has sufficient energy to effectively bombard the substrate surface. The nitrogen flow rate is coordinated with the treatment time, guaranteeing the stability of the ion beam source and the uniformity of the treatment effect. The combination of these parameters enables the formation of micro / nano structures with a roughness Ra of 0.1-0.5 μm and a protrusion size of 50-500 nm on the substrate surface.

[0039] Preferably, after surface modification with a high-energy nitrogen ion beam, argon gas is introduced into the sputtering environment to control the coating pressure at 0.1-0.3 Pa. Then, an antibacterial coating is deposited on the substrate surface via co-sputtering. The co-sputtering parameters include a cuprous oxide target power density of 2-5 W / cm². 2 The power density of the polytetrafluoroethylene target is 1-3 W / cm². 2 The sputtering time is 20-60 min. By independently adjusting the power density of the two targets, the relative content and deposition rate of hard metal oxides and hydrophobic polytetrafluoroethylene in the coating can be precisely controlled, forming a composite state in which the components are interwoven at the nanoscale, uniformly dispersed, and dense. This results in a coating with comprehensive properties such as high hardness, high hydrophobicity, efficient antibacterial properties, and excellent adhesion. The set sputtering time can stably control the coating thickness within 0.5-5 μm.

[0040] Preferably, the molar ratio of copper oxide to cuprous oxide in the antibacterial coating is adjusted by controlling whether oxygen is introduced into the sputtering environment and the flow rate of oxygen. Specifically, during co-sputtering without the introduction of oxygen, the molar ratio of copper oxide to cuprous oxide in the deposited coating is approximately 1:1; while introducing oxygen into the sputtering environment increases the proportion of copper oxide in the coating, thereby adjusting the molar ratio of copper oxide to cuprous oxide to the range of 1:1 to 3:1. By controlling whether oxygen is introduced and adjusting its flow rate, the molar ratio of copper oxide to cuprous oxide in the antibacterial coating can be flexibly controlled, thereby achieving control over the bactericidal performance and hardness of the coating to adapt to medical devices with different clinical needs. More preferably, when oxygen is introduced into the sputtering environment, the oxygen flow rate is 5-15 sccm.

[0041] Preferably, during the co-sputtering deposition process, a bias voltage of -50V to -200V and a frequency of 10-50kHz is applied to the substrate. This enhances the energy and density of the coating particles, thereby improving the adhesion between the coating and the substrate.

[0042] Furthermore, the purity of the cuprous oxide target is ≥99.5%, and the purity of the polytetrafluoroethylene target is ≥99.9%.

[0043] Example 1

[0044] This embodiment provides an antibacterial coating for the surface of medical devices, using medical stainless steel surgical scissors as the substrate. The preparation process is as follows:

[0045] Medical stainless steel surgical scissors were selected as the substrate and subjected to mechanical grinding, degreasing, rust removal, cleaning and drying processes in sequence to remove surface impurities, oxide layers and oil stains, resulting in a clean and flat substrate.

[0046] The pretreated surgical scissors are placed into a magnetron sputtering device equipped with an ion beam source. The device contains cuprous oxide and polytetrafluoroethylene targets, both of which are connected to an RF power supply, and the substrate is connected to a bias power supply.

[0047] a. High-energy nitrogen ion beam surface modification: Evacuate the equipment cavity to 3×10⁻⁶ ℃ -3 A nitrogen gas flow rate of 10 sccm was introduced as the ion source. The substrate surface was irradiated with a high-energy nitrogen ion beam with the following parameters: accelerating voltage 10 keV, beam current density 0.5 mA / cm², and irradiation time 5 min. After irradiation, a micro-nano rough structure with a roughness Ra of 0.1 μm and micro-nano protrusion sizes of 50-200 nm was formed on the substrate surface.

[0048] b. Magnetron Co-sputtering Deposition of Composite Coating: After ion beam modification, maintain a vacuum environment in the equipment, introduce argon gas into the chamber, and control the coating gas pressure to 0.1 Pa. The deposition process is carried out at room temperature. Set the substrate bias parameters as follows: bias voltage -50V, bias frequency 10kHz. Start magnetron co-sputtering, with the power density of the cuprous oxide target set to 2W / cm² and the power density of the polytetrafluoroethylene target set to 1W / cm². No oxygen is introduced during sputtering. Co-sputtering deposition is performed for 20 minutes, forming a composite coating with a thickness of approximately 0.5μm. Through this process, the molar ratio of copper oxide to cuprous oxide in the coating is 1:1, and the total molar number of copper oxide and cuprous oxide is in a molar ratio of 1:1.6 to that of polytetrafluoroethylene.

[0049] After sputtering is completed, the surgical scissors are cooled to room temperature inside the equipment cavity and then removed without annealing, thus obtaining medical surgical scissors with an antibacterial coating deposited on the surface.

[0050] The antibacterial coating prepared in this embodiment was tested and found to have a hardness of 820 HV. The adhesion between the coating and the substrate was tested using the scratch method, and the critical load Lc ≥ 28 N, indicating a strong bond between the coating and the stainless steel substrate. The coating surface exhibits good hydrophobicity, with a water contact angle of 115°. Regarding antibacterial performance, the coating achieved a 99.9% bactericidal rate against both Escherichia coli and Staphylococcus aureus, and an 85.6% bactericidal rate after immersion in simulated body fluids for 7 days. Under simulated usage conditions, after 1000 cycles of reciprocating friction and 50 simulated clinical cleanings, the coating maintained its structural integrity, hydrophobicity (water contact angle > 100°), and antibacterial performance remained stable.

[0051] Example 2

[0052] This embodiment provides an antibacterial coating for the surface of medical devices, using medical stainless steel surgical scissors as the substrate. The preparation process is as follows:

[0053] Medical stainless steel surgical scissors were selected as the substrate and subjected to mechanical grinding, degreasing, rust removal, cleaning and drying processes in sequence to remove surface impurities, oxide layers and oil stains, resulting in a clean and flat substrate.

[0054] The pretreated surgical scissors are placed into a magnetron sputtering device equipped with an ion beam source. The device contains cuprous oxide and polytetrafluoroethylene targets, both of which are connected to an RF power supply, and the substrate is connected to a bias power supply.

[0055] a. High-energy nitrogen ion beam surface modification: Evacuate the equipment cavity to 4×10⁻⁶ ℃ -3 A nitrogen gas flow rate of 20 sccm was introduced as the ion source. The substrate surface was irradiated with a high-energy nitrogen ion beam with the following parameters: accelerating voltage 20 keV, beam current density 1.2 mA / cm², and irradiation time 12 min. After irradiation, a micro-nano rough structure with a roughness Ra of 0.3 μm and micro-nano protrusions of 200-350 nm was formed on the substrate surface.

[0056] b. Magnetron Co-sputtering Deposition of Composite Coating: After ion beam modification, maintain a vacuum environment in the equipment, introduce argon gas into the chamber, and control the coating gas pressure at 0.2 Pa. The deposition process is carried out at room temperature. Set the substrate bias parameters as follows: bias voltage -120V, bias frequency 30kHz. Start magnetron co-sputtering, with the power density of the cuprous oxide target set to 3.5W / cm², the power density of the polytetrafluoroethylene target set to 2W / cm², and oxygen flow rate of 10 sccm. Co-sputtering deposition is performed for 40 min, forming a composite coating with a thickness of approximately 3.0 μm. Through this process, the molar ratio of copper oxide to cuprous oxide in the coating is 2:1, and the molar ratio of copper oxide / cuprous oxide to polytetrafluoroethylene is 1:2.2.

[0057] After sputtering is completed, the surgical scissors are cooled to room temperature inside the equipment cavity and then removed without annealing, thus obtaining medical surgical scissors with an antibacterial coating deposited on the surface.

[0058] The antibacterial coating prepared in this embodiment was tested and found to have a hardness of 910 HV. The adhesion between the coating and the substrate was tested using the scratch method, and the critical load Lc ≥ 42 N, indicating a strong bond between the coating and the stainless steel substrate. The coating surface exhibits good hydrophobicity, with a water contact angle of 130°. Regarding antibacterial performance, the coating showed a bactericidal rate of ≥99.9% against both Escherichia coli and Staphylococcus aureus, and the bactericidal rate remained ≥99.8% after immersion in simulated body fluids for 7 days. Under simulated usage conditions, after 5000 cycles of friction and 200 simulated clinical cleanings, the coating maintained its structural integrity, hydrophobicity (water contact angle >125°), and antibacterial performance.

[0059] Example 3

[0060] This embodiment provides an antibacterial coating for the surface of medical devices, using medical stainless steel surgical scissors as the substrate. The preparation process is as follows:

[0061] Medical stainless steel surgical scissors were selected as the substrate and subjected to mechanical grinding, degreasing, rust removal, cleaning and drying processes in sequence to remove surface impurities, oxide layers and oil stains, resulting in a clean and flat substrate.

[0062] The pretreated surgical scissors are placed into a magnetron sputtering device equipped with an ion beam source. The device contains cuprous oxide and polytetrafluoroethylene targets, both of which are connected to an RF power supply, and the substrate is connected to a bias power supply.

[0063] a. High-energy nitrogen ion beam surface modification: Evacuate the equipment cavity to 5×10⁻⁶ ℃ -3 A nitrogen gas flow rate of 30 sccm was introduced as the ion source. The substrate surface was irradiated with a high-energy nitrogen ion beam with the following parameters: accelerating voltage 30 keV, beam current density 2.0 mA / cm², and irradiation time 20 min. After irradiation, a micro-nano rough structure with a roughness Ra of 0.5 μm and micro-nano protrusion sizes of 100-450 nm was formed on the substrate surface.

[0064] b. Magnetron Co-sputtering Deposition of Composite Coating: After ion beam modification, maintain a vacuum environment in the equipment, introduce argon gas into the chamber, and control the coating gas pressure at 0.3 Pa. The deposition process is carried out at room temperature. Set the substrate bias parameters as follows: bias voltage -200V, bias frequency 50kHz. Start magnetron co-sputtering, with the power density of the cuprous oxide target set to 5.0 W / cm², the power density of the polytetrafluoroethylene target set to 3.0 W / cm², and oxygen flow rate at 15 sccm. Co-sputtering deposition is performed for 60 min, forming a composite coating with a thickness of approximately 5.0 μm. Through this process, the molar ratio of copper oxide to cuprous oxide in the coating is 3:1, and the molar ratio of copper oxide / cuprous oxide to polytetrafluoroethylene is 1:3.

[0065] After sputtering is completed, the surgical scissors are cooled to room temperature inside the equipment cavity and then removed without annealing, thus obtaining medical surgical scissors with an antibacterial coating deposited on the surface.

[0066] The antibacterial coating prepared in this embodiment was tested and found to have a hardness of 980 HV. The adhesion between the coating and the substrate was tested using the scratch method, and the critical load Lc ≥ 23 N, indicating that the coating is firmly bonded to the stainless steel substrate. The coating surface has good hydrophobicity, with a water contact angle of 108°. In terms of antibacterial performance, the coating has a bactericidal rate of ≥ 99.9% against Escherichia coli and Staphylococcus aureus, and the bactericidal rate remains ≥ 87.4% after immersion in simulated body fluid for 7 days. Under simulated use conditions, the coating can still maintain structural integrity, hydrophobicity (water contact angle > 90°), and antibacterial performance after 1000 rubs.

[0067] Example 4

[0068] This embodiment provides an antibacterial coating for the surface of medical devices, using medical stainless steel surgical scissors as the substrate. The preparation process is as follows:

[0069] Medical stainless steel surgical scissors were selected as the substrate and subjected to mechanical grinding, degreasing, rust removal, cleaning and drying processes in sequence to remove surface impurities, oxide layers and oil stains, resulting in a clean and flat substrate.

[0070] The pretreated surgical scissors are placed into a magnetron sputtering device equipped with an ion beam source. The device contains cuprous oxide and polytetrafluoroethylene targets, both of which are connected to an RF power supply, and the substrate is connected to a bias power supply.

[0071] a. High-energy nitrogen ion beam surface modification: Evacuate the equipment cavity to 5×10⁻⁶ ℃ -3A nitrogen gas flow rate of 25 sccm was introduced as the ion source. The substrate surface was irradiated with a high-energy nitrogen ion beam with the following parameters: accelerating voltage 25 keV, beam current density 1.5 mA / cm², and irradiation time 15 min. After irradiation, a micro-nano rough structure with a roughness Ra of 0.4 μm and micro-nano protrusion sizes of 100-400 nm was formed on the substrate surface.

[0072] b. Magnetron Co-sputtering Deposition of Composite Coating: After ion beam modification, maintain a vacuum environment in the equipment, introduce argon gas into the chamber, and control the coating gas pressure at 0.25 Pa. The deposition process is carried out at room temperature. Set the substrate bias parameters as follows: bias voltage -150V, bias frequency 40kHz. Start magnetron co-sputtering, with the power density of the cuprous oxide target set to 4.0 W / cm², the power density of the polytetrafluoroethylene target set to 1.8 W / cm², and oxygen flow rate at 12 sccm. Co-sputtering deposition is performed for 50 min, forming a composite coating with a thickness of approximately 3.0 μm. Through this process, the molar ratio of copper oxide to cuprous oxide in the coating is 2.5:1, and the molar ratio of copper oxide / cuprous oxide to polytetrafluoroethylene is 1:1.8.

[0073] After sputtering is completed, the surgical scissors are cooled to room temperature inside the equipment cavity and then removed without annealing, thus obtaining medical surgical scissors with an antibacterial coating deposited on the surface.

[0074] The antibacterial coating prepared in this embodiment was tested and found to have a hardness of 930 HV. The adhesion between the coating and the substrate was tested using the scratch test, and the critical load Lc ≥ 38 N, indicating a strong bond between the coating and the stainless steel substrate. The coating surface exhibits good hydrophobicity, with a water contact angle of 125°. Regarding antibacterial performance, the coating showed a bactericidal rate of ≥99.9% against both Escherichia coli and Staphylococcus aureus, and the bactericidal rate remained ≥96.6% after immersion in simulated body fluids for 7 days. Under simulated usage conditions, after 5000 cycles of friction and 200 simulated clinical cleanings, the coating maintained its structural integrity, hydrophobicity (water contact angle >120°), and antibacterial performance.

[0075] The above are merely preferred embodiments of this application and are not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. An antibacterial coating for the surface of medical devices, characterized in that, It contains copper oxide, cuprous oxide and polytetrafluoroethylene; wherein the molar ratio of copper oxide to cuprous oxide is 1:1 to 3:1, and the molar ratio of the total number of copper oxide and cuprous oxide to polytetrafluoroethylene is 1:1.5 to 1:

3. The coating is formed by magnetron co-sputtering, and copper oxide, cuprous oxide and polytetrafluoroethylene exist in a composite state in which they are intertwined and uniformly dispersed at the nanoscale in the coating.

2. The antibacterial coating for the surface of medical devices according to claim 1, characterized in that, The thickness of the antibacterial coating is 0.5-5μm.

3. The antibacterial coating for the surface of medical devices according to claim 1, characterized in that, The antibacterial coating is used to cover the medical device substrate that has undergone surface modification treatment with high-energy nitrogen ion beam. The surface of the substrate has a micro-nano rough structure with a roughness Ra of 0.1-0.5μm and a size of 50-500nm for the micro-nano protrusions.

4. The antibacterial coating for the surface of medical devices according to any one of claims 1-3, characterized in that, The antibacterial coating is prepared by a method comprising the following steps: The pretreated medical device substrate is placed in a magnetron sputtering device equipped with an ion beam source, and the substrate surface is irradiated with a high-energy nitrogen ion beam to form a micro-nano rough structure on the substrate surface; an antibacterial coating is deposited on the substrate surface with the micro-nano rough structure by co-sputtering. The sputtering targets are cuprous oxide and polytetrafluoroethylene, and the deposition process is carried out at room temperature.

5. The antibacterial coating for the surface of medical devices according to claim 4, characterized in that, The sputtering environment was evacuated to a vacuum level ≤ 5 × 10⁻⁶. -3 A nitrogen gas was introduced as the ion source to irradiate the substrate surface with a high-energy nitrogen ion beam. The parameters for the high-energy nitrogen ion beam irradiation included: accelerating voltage of 10-30 keV and beam current density of 0.5-2 mA / cm². 2 The irradiation time is 5-20 minutes, and the nitrogen flow rate is 10-30 sccm.

6. The antibacterial coating for the surface of medical devices according to claim 4, characterized in that, Argon gas is introduced into the sputtering environment, and the coating pressure is controlled at 0.1-0.3 Pa. Then, an antibacterial coating is deposited on the substrate surface by co-sputtering. The co-sputtering parameters include: a power density of 2-5 W / cm³ for the cuprous oxide target. 2 The power density of the polytetrafluoroethylene target is 1-3 W / cm². 2 Sputtering time: 20-60 min.

7. The antibacterial coating for the surface of medical devices according to claim 4, characterized in that, The molar ratio of copper oxide to cuprous oxide in the antibacterial coating is adjusted by controlling whether oxygen is introduced into the sputtering environment and the flow rate of oxygen.

8. The antibacterial coating for the surface of medical devices according to claim 7, characterized in that, When oxygen is introduced into the sputtering environment, the oxygen flow rate is 5-15 sccm.

9. The antibacterial coating for the surface of medical devices according to claim 4, characterized in that, During co-sputtering deposition, a bias voltage is applied to the substrate, ranging from -50V to -200V, with a frequency of 10-50kHz.

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