A biological coating with physical-mechanical and chemical antibacterial properties and a method for its preparation

Abstract

The application discloses a kind of biological coating with physical mechanical antibacterial and chemical antibacterial performance and preparation method thereof, it is related to biomaterial technical field.The biological coating of the application is composed of TC4 nanofiber network and nano copper deposited in nanofiber network, and the preparation method is: using polishing-washing-sweeping process pretreatment TC4 titanium alloy;It is placed in alkali solution and heated in water bath to activate, and the alloy after activation is repeated polishing, washing, sweeping step, to obtain the substrate to be sputtered;The substrate is magnetron sputtered, and nano copper is deposited on its surface;After depositing nano copper, the substrate is annealed in inert atmosphere and cooled, and the biological coating with physical mechanical antibacterial and chemical antibacterial performance is prepared.The synergistic effect of the biological coating composed of nano copper and nanofiber network can effectively kill staphylococcus aureus, escherichia coli and other pathogenic microorganisms, and can be applied to oral implant, metal implant biomaterial as functional coating.

Description

Technical Field

[0001] This invention relates to a bio-coating with physical, mechanical, and chemical antibacterial properties and its preparation method, belonging to the field of biomaterials technology. Background Technology

[0002] Medical-grade titanium alloy (TC4) is widely used in orthopedic implants, dental implants, cardiovascular stents, and various surgical instruments due to its excellent mechanical properties, wear resistance, and good biocompatibility. In clinical applications, the stable mechanical properties and biocompatibility of titanium alloys make them one of the most widely used metal implant materials. However, titanium alloy surfaces do not possess inherent antibacterial activity, making them highly susceptible to bacterial adhesion and biofilm formation after implantation. Common pathogens such as Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa can rapidly multiply on their surfaces. Once such infections occur, they not only weaken the bond between the implant and surrounding bone or soft tissue but also induce persistent inflammatory responses, leading to surgical failure, implant loosening, and even the need for secondary surgery, posing a serious threat to the patient's health. Therefore, how to impart durable antibacterial properties to titanium alloys while maintaining their inherent excellent mechanical properties is a pressing problem to be solved in the field of biomedical materials.

[0003] To enhance the antibacterial properties of titanium alloys, existing research has proposed various modification methods. For example, grafting antibacterial organic molecules or polymer coatings onto the surface can reduce bacterial adhesion to some extent, but these materials are prone to detachment and failure under the flushing action of bodily fluids, making it difficult to maintain long-term stable antibacterial effects. Another approach is to load antibiotic drugs, utilizing the short-term high-efficiency antibacterial properties of the drugs; however, these coatings suffer from problems such as rapid drug release and rapid attenuation of antibacterial effects, while also increasing the risk of drug-resistant bacteria. Ion implantation or spraying of metallic materials can improve surface properties to some extent, but these processes are complex and costly, and the modified coatings are often not evenly distributed, easily leading to insufficient local antibacterial effects. In addition, the rapid release of some metal elements can also cause cytotoxicity, adversely affecting the long-term safety of the material. Overall, existing methods often struggle to achieve both long-lasting, broad-spectrum antibacterial properties and good biocompatibility, which has become a bottleneck restricting the further development of titanium alloys.

[0004] To address the aforementioned issues, this invention proposes a novel synergistic preparation method integrating surface activation, magnetron sputtering, and annealing. This method constructs a porous nanofiber network structure on the surface of medical-grade titanium alloy TC4. This structure not only improves surface roughness and hydrophilicity, promoting osteoblast adhesion and osteointegration, but its sharp nanofibers can also directly physically damage the cell walls of adherent bacteria, forming a long-lasting physical antibacterial mechanism independent of drug consumption. Furthermore, the preparation method of this invention enhances the structural stability of the film, enabling a stable and controllable release of copper ions, thereby exerting a sustained chemical antibacterial effect. This results in the construction of a composite coating system on the surface of medical-grade titanium alloy that possesses both excellent osteogenic activity and long-lasting dual antibacterial function.

[0005] Therefore, the modified TC4 composite surface constructed in this invention possesses a synergistic effect of both physical-mechanical and chemical antibacterial mechanisms: on the one hand, the nanofiber network can directly disrupt bacterial structure and inhibit initial bacterial attachment; on the other hand, the nano-copper film provides a sustained chemical bactericidal effect by stably releasing copper ions. This interaction not only significantly enhances the broad-spectrum antibacterial properties of the material but also maintains good biocompatibility over a long period, avoiding the drawbacks of traditional organic antibacterial molecules or antibiotics due to inactivation or drug resistance.

[0006] In summary, this invention innovatively constructs a synergistic antibacterial composite structure on the surface of medical titanium alloy TC4 by utilizing magnetron sputtering combined with surface modification processes. This not only overcomes the shortcomings of existing modification methods but also ensures the long-term safety and effectiveness of the material in medical applications, demonstrating promising application prospects. Summary of the Invention

[0007] To address the shortcomings of related technologies, this invention provides a bio-coating with physical-mechanical and chemical antibacterial properties and its preparation method. It possesses excellent hydrophilicity, long-lasting antibacterial effect, and good cell compatibility, which can meet the functional requirements of implant materials. It is suitable as a functional surface for use in orthopedic implants, dental implants, and other surgical instruments, solving the problem of poor application effects of traditional organic antibacterial molecules or antibiotics due to inactivation or drug resistance.

[0008] One of the objectives of this invention is to provide a bio-coating with physical-mechanical and chemical antibacterial properties, the bio-coating being composed of a TC4 nanofiber network and copper nanoparticles deposited in the nanofiber network.

[0009] Preferably, the TC4 nanofiber network has a recess depth of 50-80 nm and a protrusion height of 50-90 nm.

[0010] Preferably, the copper nanoparticles are spherical with an average diameter of 15-25 nm.

[0011] Another objective of this invention is to provide a method for preparing a bio-coating with both physical and mechanical antibacterial and chemical antibacterial properties, specifically comprising the following steps: (1) Grind, clean and blow the TC4 titanium alloy to obtain the pretreated TC4 titanium alloy substrate.

[0012] (2) The pretreated TC4 titanium alloy substrate is placed in an alkaline solution and heated in a water bath to obtain the activated TC4 titanium alloy. The grinding, cleaning and purging operations of step (1) are repeated on the activated TC4 titanium alloy to obtain the substrate to be sputtered.

[0013] (3) Fix the substrate to be sputtered in the magnetron sputtering device, install the Cu target in the magnetron sputtering device, deposit nano-copper on the substrate to be sputtered, and obtain a substrate with deposited nano-copper.

[0014] (4) The substrate with deposited nano-copper was annealed in an inert atmosphere and then cooled to obtain a bio-coating with physical and mechanical antibacterial and chemical antibacterial properties.

[0015] Preferably, in step (1), TC4 titanium alloy is polished with sandpaper of 1000 grit, 1500 grit and 2000 grit in sequence.

[0016] More preferably, the TC4 titanium alloy after grinding in step (1) is ultrasonically cleaned sequentially with water, anhydrous ethanol, and acetone, and then purged with an N2 gun.

[0017] Preferably, the alkaline solution in step (2) is a 4 mol / L NaOH aqueous solution; the water bath heating conditions are: heating at 80-90℃ for 90-100 min.

[0018] Preferably, the conditions for depositing nano-copper on the substrate to be sputtered in step (3) are: a vacuum degree of 3 × 10⁻⁶. -4 Pa-5×10 -4 The sputtering parameters are: Pa, substrate rotation speed: 15 rpm, sputtering distance: 75 mm, sputtering working pressure: 0.75-1.0 Pa, sputtering power: 25 W, and sputtering time: 10 s.

[0019] More preferably, the purity of the Cu target in step (3) is ≥99%.

[0020] Preferably, the annealing conditions in step (4) are: heating to 500°C at a heating rate of 1-5°C / min and holding at that temperature for 3600s.

[0021] More preferably, the inert atmosphere in step (4) is N2 atmosphere.

[0022] Mechanism of the invention: This invention proposes a novel synergistic preparation method integrating surface activation, magnetron sputtering, and annealing. This method generates a large number of hydrophilic hydroxyl groups on the TC4 surface, transforming it into a superhydrophilic surface. This reduces initial bacterial adhesion and, combined with the physical penetration effect of nanofibers, exerts a mechanical antibacterial effect. Due to the synergistic effect of surface activation, magnetron sputtering, and annealing, the activated surface acquires copper ions, a rapid and potent antibacterial factor, endowing it with chemical antibacterial capabilities. Simultaneously, it achieves a stable and continuous release of copper ions, resulting in highly efficient chemical antibacterial effects. The mechanical antibacterial effect obtained from surface activation and the chemical antibacterial effect from nano-copper ions obtained from magnetron sputtering have a synergistic enhancement effect, significantly improving antibacterial performance while maintaining excellent biocompatibility.

[0023] The beneficial effects of this invention are: (1) Surface structure optimization: A porous nanofiber network structure was constructed on the TC4 surface through surface modification. This structure significantly increased the surface roughness and specific surface area, transforming the substrate from a normal wettability to a superhydrophilic surface. This structural and wettability transformation not only improved the surface roughness but also reduced the initial bacterial adhesion and exerted a mechanical antibacterial effect by combining the physical puncture effect of nanofibers.

[0024] (2) Enhanced chemical antibacterial properties: A nano-copper film is uniformly deposited on the modified surface and then annealed and stabilized to enable it to continuously release copper ions at a stable rate, thereby exerting a highly efficient chemical antibacterial effect and effectively killing pathogenic bacteria such as Staphylococcus aureus and Escherichia coli.

[0025] (3) Synergistic effect of physical and chemical antibacterial mechanisms: This invention significantly improves antibacterial performance through the synergistic effect of two mechanisms: physical and mechanical antibacterial effect of nanofiber network and chemical antibacterial effect of release of nano copper ions. It has stronger durability and broad spectrum, avoiding the defects of traditional organic antibacterial molecules or antibiotics that are easy to become ineffective and easy to develop drug resistance.

[0026] (4) Significant process advantages: The ultra-short time magnetron sputtering process (10s) can prepare a uniform and dense nano-copper film layer in a very short time, with high process efficiency and controllable composition. At the same time, combined with annealing treatment, the film structure is more stable and the antibacterial durability is improved.

[0027] (5) Good biocompatibility: While possessing strong antibacterial properties, the composite surface maintains the excellent biocompatibility of titanium alloy. It will not cause cytotoxicity due to excessive ion release or uneven local structure, ensuring its long-term safety in medical implantation environments. Attached Figure Description

[0028] Figure 1 These are 3D surface microstructure images of the bio-coated atomic force microscopes (AFM) prepared in Example 1 and Comparative Example 1 of the present invention.

[0029] Figure 2 The images shown are SEM images of the bio-coated surfaces prepared in Example 1 and Comparative Example 1 of this invention.

[0030] Figure 3 The images show the water contact angle test results of the bio-coatings prepared in Example 1 and Comparative Example 1 of this invention.

[0031] Figure 4 The images show colony diagrams of the biocoatings prepared in Example 1 and Comparative Example 1 of this invention after being directly contacted with Escherichia coli and Staphylococcus aureus for 1 hour and then cultured in bacterial suspensions for 24 hours.

[0032] Figure 5 This is a cell compatibility evaluation diagram of the biocoatings prepared in Example 1 and Comparative Example 1 of this invention, tested with MC3T3-E1 cells. Detailed Implementation

[0033] To better illustrate the purpose, technical solution, and advantages of this invention, the invention will be further described below with reference to specific embodiments. In the embodiments and comparative examples of this invention, unless otherwise specified, all chemical reagents were commercially available analytical grade. The Cu target used in the embodiments and comparative examples of this invention had a purity of 99%.

[0034] Example 1 A method for preparing a bio-coating with physical-mechanical and chemical antibacterial properties specifically includes the following steps: (1) The TC4 titanium alloy was polished with 1000 grit, 1500 grit and 2000 grit sandpaper in sequence, and then ultrasonically cleaned with deionized water, anhydrous ethanol and acetone in sequence to remove particulate contaminants, grease and organic residues attached to the surface. After that, it was blown clean with N2 gun to obtain the pretreated TC4 titanium alloy substrate.

[0035] (2) The pretreated TC4 titanium alloy substrate was placed in a 4 mol / L NaOH aqueous solution and heated in a water bath at 85°C for 90 min to obtain the activated TC4 titanium alloy. The grinding, cleaning and purging operations of step (1) were repeated on the activated TC4 titanium alloy to obtain the substrate to be sputtered.

[0036] (3) Fix the substrate to be sputtered on the sample stage in the magnetron sputtering sample chamber, install the Cu target on the DC target position and keep it at 45° with the horizontal direction, seal the magnetron sputtering chamber, and start the mechanical pump and molecular pump to evacuate the vacuum in the sputtering chamber to a vacuum level of 4×10⁻⁶. -4 Under the conditions of Pa, sample stage rotation speed of 15 rpm, sputtering distance of 75 mm, sputtering working gas pressure of 0.75 Pa, sputtering power of 25 W, and sputtering time of 10 s, nano-copper was deposited on the substrate to be sputtered, resulting in a substrate with deposited nano-copper.

[0037] (4) The substrate with deposited nano-copper was placed in an annealing furnace and heated to 500°C at a heating rate of 5°C / min under N2 atmosphere. The temperature was held for 3600s for annealing treatment, and then naturally cooled to room temperature to obtain a biological coating with physical and mechanical antibacterial and chemical antibacterial properties.

[0038] The bio-coating with physical-mechanical and chemical antibacterial properties prepared in this embodiment was observed using AFM 3D surface microstructure images. The test results are as follows: Figure 1 As shown, the bio-coating prepared in this embodiment is composed of TC4 with a special morphology and a nano-copper layer. After activation treatment, the surface of TC4 shows a crisscrossing nanofiber network. The special surface morphology of the TC4 nanofiber network has a depression depth of 50-80 nm and a protrusion height of 50-90 nm. The nano-copper deposited in the nanofiber network is spherical with an average diameter of about 15-25 nm.

[0039] The surface of the bio-coating with physical-mechanical and chemical antibacterial properties prepared in this embodiment was observed by SEM, and the test results are as follows: Figure 2 As shown, observations revealed that the TC4 nanofiber network still existed and was not covered by copper nanofibers, indicating that the bio-coating with physical-mechanical and chemical antibacterial properties was successfully prepared.

[0040] The bio-coating prepared in this embodiment was subjected to a water contact angle test. Deionized water was used as the test solution, and an SL200KS professional contact angle meter was used. The test results are as follows: Figure 3 As shown, tests have shown that the bio-coating prepared in this embodiment has a water contact angle of <90°, exhibiting hydrophilic properties.

[0041] The antibacterial activity of the bio-coating prepared in this embodiment against Escherichia coli and Staphylococcus aureus was tested. The bio-coating prepared in this embodiment was mixed with Escherichia coli and Staphylococcus aureus bacterial solutions (10... 6 (CFU / mL) were exposed to the solution for 1 hour, followed by 24 hours of incubation. The test results are as follows: Figure 4 As shown, tests revealed that the bio-coating prepared in this embodiment maintained an antibacterial rate of over 99% against both Escherichia coli and Staphylococcus aureus for 24 hours, indicating that the bio-coating in this embodiment achieved a synergistic enhancement of both physical-mechanical and chemical antibacterial mechanisms.

[0042] The biocompatibility of the biocoating prepared in this embodiment was tested using the CCK-8 colorimetric method. The cells used were mouse pre-osteoblast cell lines (MC3T3-E1). The test results are as follows: Figure 5As shown, tests revealed that the biocompatibility of the bio-coating prepared in this embodiment was higher than 80% after 24 hours.

[0043] Example 2 A method for preparing a bio-coating with physical-mechanical and chemical antibacterial properties specifically includes the following steps: (1) The TC4 titanium alloy was polished with 1000 grit, 1500 grit and 2000 grit sandpaper in sequence, and then ultrasonically cleaned with deionized water, anhydrous ethanol and acetone in sequence to remove particulate contaminants, grease and organic residues attached to the surface. After that, it was blown clean with N2 gun to obtain the pretreated TC4 titanium alloy substrate.

[0044] (2) The pretreated TC4 titanium alloy substrate was placed in a 4mol / L NaOH aqueous solution and heated in a 90℃ water bath for 95min to obtain the activated TC4 titanium alloy. The grinding, cleaning and purging operations of step (1) were repeated on the activated TC4 titanium alloy to obtain the substrate to be sputtered.

[0045] (3) Fix the substrate to be sputtered on the sample stage in the magnetron sputtering sample chamber, install the Cu target on the DC target position and keep it at 45° with the horizontal direction, seal the magnetron sputtering chamber, and start the mechanical pump and molecular pump to evacuate the vacuum in the sputtering chamber to a vacuum level of 3×10. -4 Under the conditions of Pa, sample stage rotation speed of 15 rpm, sputtering distance of 75 mm, sputtering working gas pressure of 1 Pa, sputtering power of 25 W, and sputtering time of 10 s, nano-copper was deposited on the substrate to be sputtered, resulting in a substrate with deposited nano-copper.

[0046] (4) The substrate with deposited nano-copper was placed in an annealing furnace and heated to 500°C at a heating rate of 1°C / min under N2 atmosphere. The temperature was held for 3600s for annealing treatment, and then naturally cooled to room temperature to obtain a biological coating with physical and mechanical antibacterial and chemical antibacterial properties.

[0047] The bio-coating with physical-mechanical and chemical antibacterial properties prepared in this embodiment was observed by AFM 3D surface micromorphology image. The test results showed that the bio-coating prepared in this embodiment was composed of TC4 with a special morphology and a nano-copper layer. After activation treatment, the surface of TC4 showed a crisscrossing nanofiber network. The depth of the depression and the height of the protrusion of the nanofiber network with special surface morphology of TC4 were similar to those in Example 1. The nano-copper deposited in the nanofiber network was spherical with an average diameter similar to that in Example 1.

[0048] The surface SEM observation of the bio-coating with physical-mechanical antibacterial and chemical antibacterial properties prepared in this embodiment showed that the TC4 nanofiber network still existed and was not covered by nano-copper, indicating that the bio-coating with physical-mechanical antibacterial and chemical antibacterial properties was successfully prepared.

[0049] The bio-coating prepared in this embodiment was subjected to a water contact angle test. Deionized water was used as the water contact angle test solution, and the test instrument was an SL200KS professional contact angle meter. The test results showed that the water contact angle of the bio-coating prepared in this embodiment was <90°, indicating that it exhibits hydrophilic properties.

[0050] The antibacterial activity of the bio-coating prepared in this embodiment against Escherichia coli and Staphylococcus aureus was tested. The bio-coating prepared in this embodiment was mixed with Escherichia coli and Staphylococcus aureus bacterial solutions (10... 6 After contacting the bio-coating (CFU / mL) for 1 hour and then culturing for 24 hours, the results showed that the bio-coating prepared in this embodiment had an antibacterial rate of over 99% against Escherichia coli and Staphylococcus aureus after 24 hours. This indicates that the bio-coating in this embodiment achieves a synergistic enhancement of both physical and mechanical antibacterial mechanisms and chemical antibacterial mechanisms.

[0051] The biocompatibility of the biocoating prepared in this embodiment was tested using the CCK-8 colorimetric method. The cells used were MC3T3-E1 cells. The test results showed that the biocompatibility of the biocoating prepared in this embodiment was higher than 80% after 24 hours.

[0052] Example 3 A method for preparing a bio-coating with physical-mechanical and chemical antibacterial properties specifically includes the following steps: (1) The TC4 titanium alloy was polished with 1000 grit, 1500 grit and 2000 grit sandpaper in sequence, and then ultrasonically cleaned with deionized water, anhydrous ethanol and acetone in sequence to remove particulate contaminants, grease and organic residues attached to the surface. After that, it was blown clean with N2 gun to obtain the pretreated TC4 titanium alloy substrate.

[0053] (2) The pretreated TC4 titanium alloy substrate was placed in a 4mol / L NaOH aqueous solution and heated in an 80℃ water bath for 100min to obtain the activated TC4 titanium alloy. The grinding, cleaning and purging operations of step (1) were repeated on the activated TC4 titanium alloy to obtain the substrate to be sputtered.

[0054] (3) Fix the substrate to be sputtered on the sample stage in the magnetron sputtering sample chamber, install the Cu target on the DC target position and keep it at 45° with the horizontal direction, seal the magnetron sputtering chamber, and start the mechanical pump and molecular pump to evacuate the vacuum in the sputtering chamber to a vacuum level of 5×10⁻⁶. -4Under the conditions of Pa, sample stage rotation speed of 15 rpm, sputtering distance of 75 mm, sputtering working gas pressure of 0.8 Pa, sputtering power of 25 W, and sputtering time of 10 s, nano-copper was deposited on the substrate to be sputtered, resulting in a substrate with deposited nano-copper.

[0055] (4) The substrate with deposited nano-copper was placed in an annealing furnace and heated to 500°C at a heating rate of 2°C / min under N2 atmosphere. The temperature was held for 3600s for annealing treatment, and then naturally cooled to room temperature to obtain a biological coating with physical and mechanical antibacterial and chemical antibacterial properties.

[0056] The bio-coating with physical-mechanical and chemical antibacterial properties prepared in this embodiment was observed by AFM 3D surface micromorphology image. The test results showed that the bio-coating prepared in this embodiment was composed of TC4 with a special morphology and a nano-copper layer. After activation treatment, the surface of TC4 showed a crisscrossing nanofiber network. The depth of the depression and the height of the protrusion of the nanofiber network with special surface morphology of TC4 were similar to those in Example 1. The nano-copper deposited in the nanofiber network was spherical with an average diameter similar to that in Example 1.

[0057] The surface SEM observation of the bio-coating with physical-mechanical antibacterial and chemical antibacterial properties prepared in this embodiment showed that the TC4 nanofiber network still existed and was not covered by nano-copper, indicating that the bio-coating with physical-mechanical antibacterial and chemical antibacterial properties was successfully prepared.

[0058] The bio-coating prepared in this embodiment was subjected to a water contact angle test. Deionized water was used as the water contact angle test solution, and the test instrument was an SL200KS professional contact angle meter. The test results showed that the water contact angle of the bio-coating prepared in this embodiment was <90°, indicating that it exhibits hydrophilic properties.

[0059] The antibacterial activity of the bio-coating prepared in this embodiment against Escherichia coli and Staphylococcus aureus was tested. The bio-coating prepared in this embodiment was mixed with Escherichia coli and Staphylococcus aureus bacterial solutions (10... 6 After contacting the bio-coating (CFU / mL) for 1 hour and then culturing for 24 hours, the results showed that the bio-coating prepared in this embodiment had an antibacterial rate of over 99% against Escherichia coli and Staphylococcus aureus after 24 hours. This indicates that the bio-coating in this embodiment achieves a synergistic enhancement of both physical and mechanical antibacterial mechanisms and chemical antibacterial mechanisms.

[0060] The biocompatibility of the biocoating prepared in this embodiment was tested using the CCK-8 colorimetric method. The cells used were MC3T3-E1 cells. The test results showed that the biocompatibility of the biocoating prepared in this embodiment was higher than 80% after 24 hours.

[0061] Comparative Example 1 A method for preparing a TC4 titanium alloy matrix with a nanoporous activated surface includes the following steps: (1) The TC4 titanium alloy was polished with 1000 grit, 1500 grit and 2000 grit sandpaper in sequence, and then ultrasonically cleaned with deionized water, anhydrous ethanol and acetone in sequence to remove particulate contaminants, grease and organic residues attached to the surface. After that, it was blown clean with N2 gun to obtain the pretreated TC4 titanium alloy substrate. (2) The pretreated TC4 titanium alloy substrate was placed in a 4mol / L NaOH aqueous solution and heated in a water bath at a temperature of 80-90℃ for 90min to obtain the activated TC4 titanium alloy. The grinding, cleaning and purging operations of step (1) were repeated on the activated TC4 titanium alloy to obtain a TC4 titanium alloy substrate with a nanoporous activated surface.

[0062] The 3D surface microstructure of the TC4 titanium alloy substrate with a nanoporous activated surface prepared in this comparative example was observed using AFM. The test results are as follows: Figure 1 As shown, tests revealed that the TC4 titanium alloy substrate prepared in this comparative example exhibits a unique nanofiber network morphology, with a crisscrossing nanofiber network appearing on the surface.

[0063] The surface of the TC4 titanium alloy substrate with a nanoporous activated surface prepared in this comparative example was observed by SEM. The test results are as follows: Figure 2 As shown, observations revealed the presence of a nanofiber network in the TC4 titanium alloy matrix.

[0064] The TC4 titanium alloy matrix prepared in this comparative example was subjected to water contact angle testing. Deionized water was used as the water contact angle test solution, and an SL200KS professional contact angle meter was used. The test results are as follows: Figure 3 As shown, the test results show that the water contact angle of the TC4 titanium alloy matrix prepared in this comparative example is <90°, indicating hydrophilic properties.

[0065] The antibacterial activity of the TC4 titanium alloy matrix prepared in this comparative example against Escherichia coli and Staphylococcus aureus was tested. The TC4 titanium alloy matrix prepared in this comparative example was mixed with bacterial suspensions of Escherichia coli and Staphylococcus aureus (10 μL / mL). 6 (CFU / mL) were exposed to the solution for 1 hour, followed by 24 hours of incubation. The test results are as follows: Figure 4 As shown, the TC4 titanium alloy matrix prepared in this comparative example showed antibacterial rates of 25% and 18% against Escherichia coli and Staphylococcus aureus, respectively, after 24 hours, according to the test results.

[0066] The biocompatibility of the TC4 titanium alloy matrix prepared in this comparative example was tested using the CCK-8 colorimetric method. MC3T3-E1 cells were used, and the test results are as follows: Figure 5 As shown, the biocompatibility of the TC4 titanium alloy matrix prepared in this comparative example is higher than 80% after 24 hours, as determined by testing.

[0067] Comparative Example 1 relies solely on its own nano-network structure for mechanical antibacterial activity, resulting in weak antibacterial ability and a lack of Cu. 2+ Direct bactericidal factors, and their surface active sites are easily passively covered by ions / proteins in the culture medium environment, resulting in a more bactericidal effect rather than efficient killing, leading to insufficient antibacterial ability.

[0068] The various embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or improvement of the technology in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A bio-coating with physical-mechanical and chemical antibacterial properties, characterized in that, The bio-coating consists of a TC4 nanofiber network and copper nanoparticles deposited in the nanofiber network.

2. The bio-coating with physical-mechanical and chemical antibacterial properties according to claim 1, characterized in that, The TC4 nanofiber network has a recess depth of 50-80 nm and a protrusion height of 50-90 nm.

3. The bio-coating with physical-mechanical and chemical antibacterial properties according to claim 1, characterized in that, The copper nanoparticles are spherical with an average diameter of 15-25 nm.

4. The method for preparing the bio-coating with physical-mechanical and chemical antibacterial properties as described in claim 1, characterized in that, Specifically, the following steps are included: (1) Grind, clean and blow the TC4 titanium alloy to obtain the pretreated TC4 titanium alloy substrate; (2) The pretreated TC4 titanium alloy substrate is placed in an alkaline solution and heated in a water bath to obtain the activated TC4 titanium alloy. The grinding, cleaning and purging operations of step (1) are repeated on the activated TC4 titanium alloy to obtain the substrate to be sputtered. (3) Fix the substrate to be sputtered in the magnetron sputtering device, install the Cu target in the magnetron sputtering device, deposit nano-copper on the substrate to be sputtered, and obtain a substrate with deposited nano-copper. (4) The substrate with deposited nano-copper was annealed in an inert atmosphere and then cooled to obtain a bio-coating with physical and mechanical antibacterial and chemical antibacterial properties.

5. The method for preparing a bio-coating with physical-mechanical and chemical antibacterial properties according to claim 4, characterized in that, In step (1), TC4 titanium alloy is polished with sandpaper of 1000 grit, 1500 grit, and 2000 grit in sequence.

6. The method for preparing a bio-coating with physical-mechanical and chemical antibacterial properties according to claim 4, characterized in that, In step (2), the alkaline solution is a 4 mol / L NaOH aqueous solution; the water bath heating conditions are: heating at 80-90℃ for 90-100 min.

7. The method for preparing a bio-coating with physical-mechanical and chemical antibacterial properties according to claim 4, characterized in that, The conditions for depositing nano-copper on the substrate to be sputtered in step (3) are: a vacuum degree of 3 × 10⁻⁶. -4 Pa-5×10 - 4 The sputtering parameters are: Pa, substrate rotation speed: 15 rpm, sputtering distance: 75 mm, sputtering working pressure: 0.75-1.0 Pa, sputtering power: 25 W, and sputtering time: 10 s.

8. The method for preparing a bio-coating with physical-mechanical and chemical antibacterial properties according to claim 4, characterized in that, The conditions for the annealing process in step (4) are: heating to 500℃ at a heating rate of 1-5℃ / min and holding at that temperature for 3600s.

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