A modified titanium alloy material and a method for manufacturing the same

Abstract

The application relates to a modified titanium alloy material and a preparation method thereof. The modified titanium alloy material is a nitrogen / copper ion injection layer formed on the surface of a titanium alloy material; wherein the copper ions exist in the forms of elemental copper, copper oxide and copper nitride, and the nitrogen ions exist in the forms of titanium nitride and copper nitride.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of medical materials, and particularly relates to a titanium alloy material surface modification method and a modified titanium alloy material obtained by the method. BACKGROUND

[0002] Surface modification technology refers to imparting a new structure and performance to the surface of a material by a certain process. According to the modification principle, the surface modification technology can be divided into physical surface modification technology, including isochromatic carbonization (nitriding), ion spraying, magnetron sputtering, plasma immersion ion implantation and deposition, laser surface modification, etc., and chemical surface modification technology, including electrochemical deposition, anodic oxidation, micro-arc oxidation, chemical vapor deposition, etc. Among them, the plasma immersion ion implantation and deposition (PIII&D) technology is a surface modification technology for realizing omnidirectional and uniform ion implantation. Under vacuum conditions, a gas is ionized by glow discharge to provide a plasma source, or a solid target material is ionized by an arc to generate plasma, the substrate is immersed in the plasma, and a pulsed negative high voltage is applied to the substrate to repel electrons, forming a positive ion sheath layer. Under the action of the sheath electric field, the positive ions obtain high energy and are vertically and uniformly implanted into the substrate surface in different directions. The PIII&D technology can implant a single or multiple elements simultaneously, and the modified layer is tightly combined with the substrate without obvious boundary, which is suitable for surface modification of materials with complex shapes.

[0003] Titanium alloy materials are often used to manufacture surgical implants such as dental and orthopedic implants due to their good mechanical properties, corrosion resistance and biocompatibility. However, the surface of titanium alloy materials is bioinert, which may cause bacterial infection and other problems after implantation, leading to implant failure and even endangering the patient's life. Therefore, it has clinical application value to impart high-efficiency and broad-spectrum antibacterial ability to the surface of titanium alloy materials and improve their biological activity.

[0004] Copper is one of the essential trace elements for human body, which is of great significance to maintain the structure and function of various proteins in human body. Copper is a typical antibacterial element, which can cause bacterial death by destroying cell membrane structure, inducing active oxygen production and degrading DNA (Applied and Environmental Microbiology 2011, 5: 1541-1547). In addition, copper ions can up-regulate the expression of vascular endothelial growth factor and improve cell proliferation activity, achieving the purpose of promoting neovascularization and tissue repair (Biomaterials 2010, 5: 824-831). Therefore, the introduction of copper element to the surface of titanium alloy materials can improve their antibacterial performance and promote cell proliferation. However, as a heavy metal element, copper ions have certain safety hazards to the human body, and excessive copper ions can cause cytotoxicity (Acta Biomaterialia 2016, 46: 286-298). SUMMARY

[0005] In view of the insufficient antibacterial performance and biological safety of the titanium alloy material with copper ion injection in the prior art, the purpose of the present application is to provide a modified titanium alloy material and a preparation method thereof.

[0006] In one aspect, the present application provides a modified titanium alloy material, and a nitrogen / copper ion injection layer is formed on the surface of the modified titanium alloy material; wherein the copper ions exist in the form of elemental copper, copper oxide and copper nitride, and the nitrogen ions exist in the form of titanium nitride and copper nitride.

[0007] Preferably, the atomic percentage of the copper ions in the nitrogen / copper ion injection layer is ≤15% (preferably 2-15%), and the atomic percentage of the nitrogen ions is ≤10% (preferably 2-10%).

[0008] Preferably, the injection depth of the copper ions and the nitrogen ions is 0-200 nm; and the contact angle of the nitrogen / copper ion injection layer is 48-72°.

[0009] In another aspect, the present application provides a surface modification method of a titanium alloy material (i.e. a preparation method of a modified titanium alloy material), which sequentially injects nitrogen ions and copper ions on the surface of the titanium alloy material by using plasma immersion ion implantation and deposition technology, so as to endow the titanium alloy material with high-efficiency antibacterial performance and maintain good cell compatibility. In the present application, the nitrogen ions convert part of the copper ions into Cu3N with electro-catalytic properties, so as to form a Cu3N / Cu-titanium alloy galvanic corrosion pair on the surface of the titanium alloy, the Cu3N catalytically enhances the galvanic corrosion reaction rate, and thus destroys the micro-environmental balance on the surface of the material, so as to kill bacteria.

[0010] Preferably, the sequential injection comprises: using nitrogen gas to provide nitrogen ions, and single-injecting the nitrogen ions into the titanium alloy material; and using pure copper as a cathode to generate copper ions, and single-injecting the copper ions into the titanium alloy material.

[0011] Preferably, the injection sequence of the nitrogen ions and the copper ions is: nitrogen injection first and then copper injection, copper injection first and then nitrogen injection, and nitrogen / copper ion co-injection. In the present application, the antibacterial rates of the single-injection of the copper ions into the surface of the titanium alloy material against Escherichia coli and Staphylococcus aureus are 28.4% and 8.9% respectively, and the sequential injection of the nitrogen ions and the copper ions into the surface of the titanium alloy material significantly improves the antibacterial performance thereof, especially the sequential injection of the copper ions and the nitrogen ions into the surface of the titanium alloy material, the antibacterial rates of which against Escherichia coli and Staphylococcus aureus both reach 100%, and good cell compatibility is maintained.

[0012] Preferably, when the nitrogen ions are single-injected, the process parameters of the plasma immersion ion implantation and deposition technology used include: the temperature of the vacuum chamber is 20-40℃; the local vacuum degree is 3×10 -3 ~1×10 -2Pa; the injection voltage is -10 to -40 kV; the frequency is 5 to 150 Hz; the pulse width is 50 to 600 mu s; the injection time is 0.5 to 2.0 h; the flow rate of nitrogen is 10 to 20 cm 3 / min, and the radio frequency power for exciting nitrogen is 100 to 140 W.

[0013] Preferably, when the copper ions are singly injected, the process parameters of the plasma immersion ion implantation and deposition technology include: the temperature of the vacuum chamber is 20 to 40 DEG C; the local vacuum degree is 3*10 -3 ~1*10 -2 Pa; the injection voltage is -10 to -40 kV; the frequency is 5 to 150 Hz; the pulse width is 50 to 600 mu s; the injection time is 0.5 to 2.0 h; the temperature for exciting the pulse of the copper cathode is 20 to 60 DEG C, the frequency is 5 to 15 Hz; and the pulse width is 50 to 600 mu s.

[0014] Preferably, the nitrogen is pure nitrogen; and the copper cathode is a pure copper cathode.

[0015] Beneficial effects:

[0016] The nitrogen ions and the copper ions are sequentially injected into the titanium alloy material by using the PIII&D technology to perform surface modification, so that a modified titanium alloy material with sequentially injected nitrogen / copper ions is obtained. The surface hydrophilicity of the modified titanium alloy material is improved, which is beneficial to the early adhesion and spreading of cells. In vitro antibacterial experiments show that the modified titanium alloy material has antibacterial performance on Escherichia coli and Staphylococcus aureus, and the antibacterial ability can be adjusted by the injection sequence, and the antibacterial rate of the modified titanium alloy material with the optimal antibacterial performance on Escherichia coli and Staphylococcus aureus reaches 100%. The live / dead cell staining experiment results prove that no dead cells are found on the surface of the titanium alloy material before and after ion implantation, and there is no cytotoxicity; the cell skeleton staining results prove that the modified titanium alloy material does not hinder the early adhesion and spreading behavior of cells; and the cell proliferation experiment results show that the modified titanium alloy material can promote cell proliferation. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 It is a scanning electron microscope image of the surface morphology of the material, wherein NiTi represents an unmodified sample, N-NiTi represents a sample with singly injected nitrogen ions, Cu-NiTi represents a sample with singly injected copper ions, Cu-N-NiTi represents a sample with nitrogen ions injected first and then copper ions, N-Cu-NiTi represents a sample with copper ions injected first and then nitrogen ions, and N&Cu-NiTi represents a sample with nitrogen / copper ions jointly injected;

[0018] Figure 2XPS survey spectra of titanium alloy material (horizontal axis: Bindding Energy), wherein NiTi represents the unmodified sample, N-NiTi represents the sample of single nitrogen ion implantation, Cu-NiTi represents the sample of single copper ion implantation, Cu-N-NiTi represents the sample of nitrogen ion implantation followed by copper ion implantation, N-Cu-NiTi represents the sample of copper ion implantation followed by nitrogen ion implantation, N&Cu-NiTi represents the sample of nitrogen / copper ion co-implantation;

[0019] Figure 3 XPS high resolution spectra of Cu 2p (a) and N 1s (b) of titanium alloy material surface (horizontal axis: Bindding Energy), wherein NiTi represents the unmodified sample, N-NiTi represents the sample of single nitrogen ion implantation, Cu-NiTi represents the sample of single copper ion implantation, Cu-N-NiTi represents the sample of nitrogen ion implantation followed by copper ion implantation, N-Cu-NiTi represents the sample of copper ion implantation followed by nitrogen ion implantation, N&Cu-NiTi represents the sample of nitrogen / copper ion co-implantation;

[0020] Figure 4 Contact angle of titanium alloy material (vertical axis: Cotact Angle), wherein NiTi represents the unmodified sample, N-NiTi represents the sample of single nitrogen ion implantation, Cu-NiTi represents the sample of single copper ion implantation, Cu-N-NiTi represents the sample of nitrogen ion implantation followed by copper ion implantation, N-Cu-NiTi represents the sample of copper ion implantation followed by nitrogen ion implantation, N&Cu-NiTi represents the sample of nitrogen / copper ion co-implantation;

[0021] Figure 5 Scanning electron microscope photos of E. coli morphology on the surface of titanium alloy material, wherein NiTi represents the unmodified sample, N-NiTi represents the sample of single nitrogen ion implantation, Cu-NiTi represents the sample of single copper ion implantation, Cu-N-NiTi represents the sample of nitrogen ion implantation followed by copper ion implantation, N-Cu-NiTi represents the sample of copper ion implantation followed by nitrogen ion implantation, N&Cu-NiTi represents the sample of nitrogen / copper ion co-implantation;

[0022] Figure 6 Scanning electron microscope photos of S. aureus morphology on the surface of titanium alloy material, wherein NiTi represents the unmodified sample, N-NiTi represents the sample of single nitrogen ion implantation, Cu-NiTi represents the sample of single copper ion implantation, Cu-N-NiTi represents the sample of nitrogen ion implantation followed by copper ion implantation, N-Cu-NiTi represents the sample of copper ion implantation followed by nitrogen ion implantation, N&Cu-NiTi represents the sample of nitrogen / copper ion co-implantation;

[0023] Figure 7Agar plate results for E. coli and S. aureus on titanium alloy material surfaces (a), colony count results (b) (vertical axis: Antibacterial Rate), wherein NiTi represents an unmodified sample, N-NiTi represents a sample of single nitrogen ion implantation, Cu-NiTi represents a sample of single copper ion implantation, Cu-N-NiTi represents a sample of nitrogen ion implantation followed by copper ion implantation, N-Cu-NiTi represents a sample of copper ion implantation followed by nitrogen ion implantation, and N&Cu-NiTi represents a sample of nitrogen / copper ion co-implantation;

[0024] Figure 8 Live / dead cell staining results for titanium alloy material surfaces (scale: 100 μm), wherein NiTi represents an unmodified sample, N-NiTi represents a sample of single nitrogen ion implantation, Cu-NiTi represents a sample of single copper ion implantation, Cu-N-NiTi represents a sample of nitrogen ion implantation followed by copper ion implantation, N-Cu-NiTi represents a sample of copper ion implantation followed by nitrogen ion implantation, and N&Cu-NiTi represents a sample of nitrogen / copper ion co-implantation;

[0025] Figure 9 Fluorescence photographs of cell early adhesion and spreading morphology on titanium alloy surfaces (scale: 100 μm), wherein NiTi represents an unmodified sample, N-NiTi represents a sample of single nitrogen ion implantation, Cu-NiTi represents a sample of single copper ion implantation, Cu-N-NiTi represents a sample of nitrogen ion implantation followed by copper ion implantation, N-Cu-NiTi represents a sample of copper ion implantation followed by nitrogen ion implantation, and N&Cu-NiTi represents a sample of nitrogen / copper ion co-implantation; 1 h, 4 h and 24 h represent the results observed after 1 h, 4 h and 24 h of incubation, respectively;

[0026] Figure 10 Cell proliferation results for titanium alloy material surfaces (vertical axis: Fluorescence Intensity), wherein NiTi represents an unmodified sample, N-NiTi represents a sample of single nitrogen ion implantation, Cu-NiTi represents a sample of single copper ion implantation, Cu-N-NiTi represents a sample of nitrogen ion implantation followed by copper ion implantation, N-Cu-NiTi represents a sample of copper ion implantation followed by nitrogen ion implantation, and N&Cu-NiTi represents a sample of nitrogen / copper ion co-implantation. DETAILED DESCRIPTION

[0027] The present application is further illustrated by the following examples, which should not be construed as limiting the present application.

[0028] In the present application, nitrogen ions and copper ions are sequentially implanted into the surface of titanium alloy material by using plasma immersion ion implantation and deposition technology to obtain modified titanium metal material, the antibacterial performance of which can be regulated by the implantation sequence, and the bioactivity of the titanium alloy material is improved. Specifically, Cu3N is formed when nitrogen and copper ions are sequentially implanted into the surface of titanium alloy, and Cu3N plays a key role in killing bacteria, and its content is positively correlated with the antibacterial capacity. The content of Cu3N on the surface of titanium alloy can be regulated by adjusting the implantation sequence

[0029] Among them, the sequential implantation refers to single implantation of nitrogen ions, single implantation of copper ions, implantation of nitrogen ions first and then implantation of copper ions, implantation of copper ions first and then implantation of nitrogen ions, and co-implantation of nitrogen ions and copper ions on the surface of titanium alloy.

[0030] Preferably, the process parameters of the plasma immersion ion implantation and deposition technology used are as follows: the temperature of the vacuum chamber is 20-40℃, the vacuum degree is 3×10 -3 ~1×10 -2 Pa, the implantation voltage is -10 to -40kV, the frequency is 5-150Hz, the pulse width is 50-600μs, and the implantation time is 0.5-2.0h.

[0031] In the present application, the hydrophilicity of the modified titanium alloy material is improved; it has good antibacterial effect on Escherichia coli and Staphylococcus aureus, and the antibacterial performance can be regulated by the implantation sequence of nitrogen ions and copper ions, and the optimal antibacterial rate reaches 100%; it has no cytotoxicity and has a promoting effect on the proliferation of endothelial cells. Specifically, the antibacterial rate of titanium alloy material implanted with nitrogen ions first and then copper ions against Escherichia coli is at least 70%, and the antibacterial rate against Staphylococcus aureus is 40%. The antibacterial rate of titanium alloy material implanted with copper ions first and then nitrogen ions against Escherichia coli is 100%, and the antibacterial rate against Staphylococcus aureus is 100%. The antibacterial rate of titanium alloy material implanted with nitrogen ions and copper ions together against Escherichia coli is at least 95%, and the antibacterial rate against Staphylococcus aureus is 80%.

[0032] The following examples are further illustrated to explain the present application. It should also be understood that the following examples are only used to further illustrate the present application, and cannot be understood as limiting the protection scope of the present application. Some non-essential improvements and adjustments made by those skilled in the art according to the above content of the present application all belong to the protection scope of the present application. The specific process parameters in the following examples are only one example in the appropriate range, i.e. those skilled in the art can select within the appropriate range according to the description herein, and are not limited to the specific values in the following examples.

[0033] Example 1

[0034] A titanium alloy material with a size of 12 mm x 12 mm x 1 mm was subjected to acid pickling (HF:HNO3:H2O = 1:5:34 vol.%) treatment, and after acid pickling for 10 min, was cleaned with deionized water and ultrapure water in sequence, and was naturally air-dried for use. Nitrogen ions and copper ions were sequentially injected into the surface of the titanium alloy by using a plasma immersion ion implantation and deposition (PIII&D) technique, and the specific process parameters are shown in Table 1 and Table 2. The sequential injection included single nitrogen ion injection, single copper ion injection, nitrogen ion injection first and then copper ion injection, copper ion injection first and then nitrogen ion injection, and nitrogen / copper ion co-injection, and the modified titanium alloy material was obtained according to the above sequence. The scanning electron microscope (SEM) morphology of the modified and unmodified titanium alloy materials is shown in Figure 1 , and the contact angle measurement results are shown in Figure 2 .

[0035] Table 1 shows the process parameters for copper ion injection:

[0036] Parameter Negative high voltage Cathode Vacuum chamber temperature (°C) 20 20 Pulse width (μs) 500 800 Frequency (Hz) 10 10 Voltage (kV) -15 - Time (h) 2 2 Vacuum (Pa) 5 x 10 -3 ]] - .

[0037] Table 2 shows the process parameters for nitrogen ion injection:

[0038] Vacuum chamber temperature (°C) 20 Pulse width (μs) 50 Frequency (Hz) 100 Voltage (kV) -30 [N2 flow (cm 3 • min -1 )]]> 10 RF power (W) 120 Time (h) 1 Vacuum (Pa) 5 x 10 -3 ]]> .

[0039] As can be seen from Figure 1 , the titanium alloy material obtained in Example 1 has a significant difference in surface, the surface of the unmodified titanium alloy material is flat and has no special morphology, the surface of the titanium alloy material with single nitrogen ion injection has uniformly distributed nanopores, and the surfaces of the titanium alloy materials with single copper ion injection, nitrogen ion injection first and then copper ion injection, copper ion injection first and then nitrogen ion injection, and nitrogen / copper ion co-injection have uniformly distributed nanoparticles.

[0040] As can be seen from Figure 2 , the nitrogen ions and copper ions are successfully injected into the titanium alloy material, with a depth of 0-200 nm, and the percentages of copper atoms on the surfaces of the titanium alloy materials obtained in Example 1 by single copper ion injection, nitrogen ion injection first and then copper ion injection, copper ion injection first and then nitrogen ion injection, and nitrogen / copper ion co-injection are 4.83%, 9.68%, 2.02% and 14.08% respectively; and the percentages of nitrogen atoms on the surfaces of the titanium alloy materials obtained in Example 1 by single nitrogen ion injection, nitrogen ion injection first and then copper ion injection, copper ion injection first and then nitrogen ion injection, and nitrogen / copper ion co-injection are 7.33%, 2.95%, 7.74% and 4.13% respectively.

[0041] As can be seen from Figure 3As can be seen, the copper element on the surface of the titanium alloy obtained by single copper ion implantation in Example 1 exists in the form of elemental copper. The copper element on the surface of the titanium alloy material implanted with nitrogen ions first, then copper ions first, then nitrogen ions first, and nitrogen / copper ions co-implanted exists in the form of elemental copper, copper nitride, and copper oxide. The nitrogen element on the surface of the titanium alloy obtained by single nitrogen ion implantation in Example 1 exists in the form of titanium nitride and nitrogen oxides. The nitrogen element on the surface of the titanium alloy material implanted with nitrogen ions first, then copper ions first, then nitrogen ions first, and nitrogen / copper ions co-implanted exists in the form of titanium nitride, copper nitride, and nitrogen oxides.

[0042] Depend on Figure 4 As can be seen, the modified titanium alloy material obtained in Example 1 has better hydrophilicity than the unmodified titanium alloy material. The surface contact angle of the unmodified titanium alloy material is 71.97±1.12°. The contact angles of the titanium alloy materials implanted with nitrogen ions alone, copper ions alone, nitrogen ions first then copper ions, copper ions first then nitrogen ions, and nitrogen / copper ions together are 48.03±7.03°, 53.69±2.22°, 63.55±1.97°, 48.07±1.20°, and 60.28±2.21°, respectively.

[0043] Example 1

[0044] Morphological observation of Escherichia coli and Staphylococcus aureus on the surface of the titanium alloy material obtained in Example 1: After sterilization with 75 vol.% alcohol, 60 μL of 10% alcohol was added... 7 CFU / mL *E. coli* culture was inoculated onto the surfaces of both unmodified and modified titanium alloy materials and cultured at 37°C for 24 h. *Staphylococcus aureus* was inoculated onto the material surfaces using the same method. The bacteria were fixed with 2.5 vol.% glutaraldehyde and then dehydrated using gradient concentrations of water / ethanol and ethanol / hexamethyldisilazane solutions. The morphology of *E. coli* and *Staphylococcus aureus* on the surfaces of both unmodified and modified titanium alloy materials was observed using scanning electron microscopy. The results are as follows: Figure 5 As shown.

[0045] Depend on Figure 5It is evident that on the surface of unmodified titanium alloy, E. coli are rod-shaped with an intact and undamaged structure. The morphology and quantity of E. coli on the surface of titanium alloy with nitrogen ion single implantation are similar to those on unmodified titanium alloy. The E. coli structure on the surface of modified titanium alloy with copper ion single implantation is basically intact, but the quantity is slightly less than that on unmodified titanium alloy and nitrogen ion single implantation modified titanium alloy. On the surface of titanium alloy with nitrogen followed by copper ion implantation, the number of E. coli is further reduced, and the bacterial structure shrinks, indicating that the material has certain antibacterial properties. On the surface of titanium alloy with copper followed by nitrogen ion implantation and with nitrogen / copper ion co-implantation, the number of E. coli is significantly less than that on the surface of unmodified titanium alloy, and the bacterial structure is severely damaged, indicating that the surface of titanium alloy with copper followed by nitrogen ion implantation and with nitrogen / copper ion co-implantation has good antibacterial properties.

[0046] The morphology of Staphylococcus aureus on the surface of titanium alloy material was observed using scanning electron microscopy, and the results are as follows: Figure 6 As shown, unmodified titanium alloy materials, titanium alloy materials implanted with nitrogen ions alone, and titanium alloy materials implanted with copper ions alone exhibit a large number of Staphylococcus aureus bacteria on their surfaces, and the structure remains basically spherical. The number of Staphylococcus aureus bacteria on the surfaces of titanium alloy materials implanted with copper ions first, followed by nitrogen ions, and titanium alloy materials implanted with both nitrogen and copper ions is significantly reduced, and bacterial division is inhibited.

[0047] Example 2

[0048] The antibacterial properties of the titanium alloy material obtained in Example 1 were quantitatively evaluated: After sterilization with 75 vol.% alcohol, Escherichia coli and Staphylococcus aureus were inhibited at 10 mmol.% respectively. 7 CFU / mL was inoculated onto the material surface, and 60 μL of bacterial suspension was added to each sample. After culturing for 24 h, the bacterial suspension was shaken and diluted. The diluted bacterial suspension was then spread evenly on the surface of an agar plate and co-cultured for 16 h. Bacterial colony images were taken on the agar plates using a gel imaging system. The number of colonies was counted and the inhibition rate was calculated. The results are as follows: Figure 7 As shown.

[0049] Depend on Figure 7As can be seen, the colony counts of *Escherichia coli* and *Staphylococcus aureus* were consistent with the electron micrographs. A large number of colonies were observed on the surfaces of unmodified titanium alloy and modified titanium alloy with nitrogen ion implantation alone after bacterial coating. No colonies were found on the surface of titanium alloy with copper-to-nitrogen ion implantation followed by nitrogen ion implantation, achieving a 100% antibacterial rate. The electron micrograph results and coating results indicate that sequential implantation of nitrogen and copper ions can impart antibacterial properties to titanium alloy materials, and the antibacterial ability can be adjusted by the implantation order of the two ions. The antibacterial rates against *Escherichia coli* were 0%, -22.2%, 28.4%, 74.4%, 100%, and 98.9% for unmodified, nitrogen-to-copper ion implantation alone, copper-to-copper ion implantation alone, nitrogen-to-copper ion implantation followed by copper ion implantation followed by nitrogen ion implantation, and nitrogen / copper ion co-implantation titanium alloy materials, respectively; and against *Staphylococcus aureus*, respectively.

[0050] Example 3

[0051] Live / dead cell staining experiment was performed on the surface of the titanium alloy material obtained in Example 1: After the sample was sterilized with 75 vol.% alcohol, 1 mL of 1×10⁻⁶ cells was added. 4 A suspension of human umbilical vein endothelial cells (cells / mL) was seeded onto the material surface and cultured at 37°C for 4 days. Afterward, a live / dead cell staining experiment was performed using a live / dead cell staining kit. After washing twice with PBS, the staining results were observed under a fluorescence microscope. Green fluorescence indicated live cells, and red fluorescence indicated dead cells. The experimental results are as follows: Figure 8 As shown.

[0052] Depend on Figure 8 It is evident that both the unmodified and ion-implanted modified titanium alloy materials exhibit a large number of live cells on their surfaces, and dead cells are difficult to observe, indicating that cells can grow normally on the surface of each group of samples, and that the ion-implanted modified titanium alloy materials have no cytotoxicity.

[0053] Example 4

[0054] Cell adhesion and spreading experiments were performed on the surface of the titanium alloy material obtained in Example 1: After the sample was sterilized with 75 vol.% alcohol, 1 mL of a material with a density of 1×10⁻⁶ was added. 4 Human umbilical vein endothelial cell suspension (cells / mL) was seeded onto the material surface and cultured in a cell culture incubator for 1, 4, and 24 hours. At each time point, the cells were washed twice with PBS, fixed with 4 wt.% paraformaldehyde (PFA), and permeabilized with 0.1 wt.% Triton. The cytoskeleton and nuclei were then stained with phalloidin and 4',6-diamidinyl-2-phenylindole, respectively. The results are shown below. Figure 9 As shown.

[0055] Depend on Figure 9As can be seen, after 1 hour of culture, the cells just adhered to the surfaces of the materials in each group, appearing as unspread spherical shapes; after 4 hours of culture, the cells began to spread on the material surfaces, and their morphology changed to polygonal; after 24 hours of culture, the cells were fully spread on the surfaces of the materials in each group, and their morphology changed from polygonal to narrow elongated shapes, with a large number of filamentous pseudopodia extending. The experimental results show that ion implantation modified titanium alloy materials have no inhibitory effect on the early adhesion and spreading of cells.

[0056] Example 5

[0057] Cell proliferation experiments were performed on the surface of the titanium alloy material obtained in Example 1: After sterilization with 75 vol.% alcohol, 1 mL of a material with a density of 1×10⁻⁶ was added. 4 A suspension of human umbilical vein endothelial cells (HVVC) at a concentration of [number] cells / mL was seeded onto the material surface and cultured in a cell culture incubator for 1, 4, and 7 days, respectively. At each time point, the samples were washed twice with PBS, and then co-cultured for 2 hours with 500 μL of medium containing 10 vol.% alpha blue. After shaking, 100 μL of the medium was taken and the fluorescence intensity was measured at an excitation wavelength of 560 nm and an emission wavelength of 590 nm. The results are as follows: Figure 10 As shown.

[0058] Depend on Figure 10 It was observed that after one day of culture, there was no significant difference in cell proliferation activity across the sample groups. After four days of culture, the cell proliferation activities of the titanium alloy materials implanted with nitrogen ions alone, copper ions alone, nitrogen followed by copper ions, copper followed by nitrogen ions, and nitrogen / copper ions in combination were all higher than those of the unmodified titanium alloy materials. After seven days of culture, ion-implanted modified titanium alloy materials still promoted cell proliferation. The experimental results indicate that ion-implanted modified titanium alloy materials not only possess good antibacterial properties but also exhibit no cytotoxicity and promote cell proliferation.

Claims

1. A modified titanium alloy material, characterized by, The nitrogen / copper ion implantation layer is formed on the surface of the titanium alloy material, wherein the copper ions exist in the forms of elemental copper, copper oxide and copper nitride, and the nitrogen ions exist in the forms of titanium nitride and copper nitride; The preparation method of the modified titanium alloy material comprises the following steps: implanting copper ions and nitrogen ions on the surface of the titanium alloy material in a sequential order by using a plasma immersion ion implantation and deposition technology. The process parameters of the plasma immersion ion implantation and deposition technique used when the copper ions are implanted include: vacuum chamber temperature of 20-40 °C; local vacuum degree of 3 x 10 -3 ~1 x 10 -2 Pa; implantation voltage of -10 to -40 kV; frequency of 5-150 Hz; pulse width of 50-600 μs; implantation time of 0.5-2.0 h; pure copper is used as the cathode to generate copper ions, the temperature of the pulse used to excite the copper cathode is 20-60 °C, the frequency is 5-15 Hz, and the pulse width is 800 μs. The process parameters of the plasma immersion ion implantation and deposition technique adopted when implanting nitrogen ions include: vacuum chamber temperature of 20-40°C; local vacuum degree of 3x10 -3 ~1x10 -2 Pa; implantation voltage of -10 to -40 kV; frequency of 5-150 Hz; pulse width of 50-600 μs; implantation time of 0.5-2.0 h; nitrogen ions are provided by nitrogen gas, the flow rate of the nitrogen gas is 10-20 cm 3 / min, and the radio frequency power for exciting the nitrogen gas is 100-140 W.

2. The modified titanium alloy material of claim 1, wherein, The percentage of copper atoms in the nitrogen / copper ion implantation layer is less than or equal to 15%, and the percentage of nitrogen atoms is less than or equal to 10%.

3. The modified titanium alloy material of claim 1, wherein, The implantation depth of the copper ions and the nitrogen ions is less than or equal to 200 nm, and the contact angle of the nitrogen / copper ion implantation layer is 48-72°.

4. The modified titanium alloy material of claim 1, wherein, The titanium alloy material is a nickel-titanium alloy.

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