Titanium alloy implant surface modification preparation method and application

Abstract

The invention belongs to the technical field of biological implant materials, and discloses a medical titanium alloy implant surface modification method and application, and the medical titanium alloy implant surface modification method comprises the following steps: grinding and polishing a titanium alloy surface, and then carrying out ultrasonic cleaning and drying in ethanol; the titanium alloy is placed in multi-arc ion plating equipment, high-purity tantalum serves as a target material, and a tantalum coating is deposited on the surface of the titanium alloy; the surface of the titanium alloy is coated with photoresist, and then a micropore array is formed in the surface of the tantalum coating through the photoetching technology; the titanium alloy is placed in the electrolyte, a Ti plate serves as a cathode, a Ta plate serves as an anode, and hydroxyapatite is deposited in a porous structure through electrochemical deposition; and removing the photoresist to expose the tantalum coating, ultrasonically cleaning with deionized water, and drying. The titanium alloy implant provided by the invention has excellent corrosion resistance, biocompatibility and mechanical properties, and makes up for the deficiency of a single material, so that the titanium alloy implant subjected to surface modification has wider application.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of biological implant materials, and particularly relates to a preparation method and application of surface modification of a titanium alloy implant. BACKGROUND

[0002] Titanium alloy is widely used in biomedical fields such as orthopedics, joint surgery and oral implantation as a human implant material due to its good biocompatibility, small density and low elastic modulus, and becomes a representative biomedical metal implant material. However, the corrosion resistance in a physiological environment needs to be improved. The occurrence of corrosion not only reduces the mechanical properties of the metal material, but also causes harmful elements to be precipitated, affecting the biocompatibility of the material. In addition, the wear resistance of titanium alloy is poor, and wear will also occur when the titanium alloy is matched with soft non-metallic materials in an artificial joint prosthesis. The existing technology improves the performance of the titanium alloy implant from the following two aspects: surface modification treatment of the titanium alloy and improvement of the alloy body performance.

[0003] Patent CN114855024B discloses a porous tantalum medical implant material and a preparation method and application thereof. The method comprises the following steps: preparing a metal foam body, the pores in the metal foam body being interconnected; filling metal powder into the pores of the metal foam body to obtain a composite body, wherein the metal powder comprises tantalum powder; performing discharge plasma sintering treatment on the composite body to obtain a sintered body; and removing the metal foam body in the sintered body to obtain the porous tantalum medical implant material. The preparation method of the porous tantalum medical implant material provided by the patent adopts discharge plasma sintering treatment to realize low-temperature sintering, avoid tantalum powder melting, and make the porous tantalum medical implant material have a rough surface morphology. This is conducive to cell adhesion and growth, and the internal through-hole structure is conducive to cell and tissue differentiation and growth inward, improves the stability effect of implantation, and increases biocompatibility.

[0004] Patent CN108904893B discloses a composite coating with antibacterial and biocompatible properties, which comprises an antibacterial coating and a biocompatible coating. The thickness of the antibacterial coating is 2-1000 nm, and the thickness of the biocompatible coating is 2-500 nm. Through the composite mode of the antibacterial coating and the biocompatible coating, the service life of the coating is prolonged, the process is simple and can be continuously carried out for large-area rapid preparation, the antibacterial effect is better, the release speed of the antibacterial element is moderate, and the biocompatible coating does not affect the release of the antibacterial element and the exertion of the antibacterial performance under the condition, which is an ideal coating for implantable medical devices.

[0005] Patent CN105624753B discloses a process for uniformly depositing a hydroxyapatite coating on a medical porous titanium and titanium alloy. The process comprises pretreatment of the porous metal substrate, preparation of an electroplating solution and an electrodeposition process.

[0006] Surface modification of implant materials is still the focus of existing research. SUMMARY

[0007] Based on the deficiencies and needs of the prior art, the present application provides a preparation method for surface modification of titanium alloy implants, which improves corrosion resistance, biocompatibility and mechanical properties by surface modification of titanium alloy implants. The titanium alloy implants after surface modification have more extensive application.

[0008] The purpose and technical effects of the present application are achieved by the following technical solutions:

[0009] A preparation method for surface modification of titanium alloy implants, comprising the following steps:

[0010] (1) polishing the surface of the titanium alloy, then ultrasonic cleaning in ethanol and drying;

[0011] (2) placing the titanium alloy in a multi-arc ion plating film equipment, using high-purity tantalum as the target material, and depositing a tantalum coating on the surface of the titanium alloy;

[0012] (3) coating photoresist on the surface of the titanium alloy, and then forming a micropore array on the surface of the tantalum coating using photolithography technology, wherein the thickness of the photoresist is 2-3 μm, the pore diameter is 1-2 μm, and the interval is 10-15 μm;

[0013] (4) placing the titanium alloy in an electrolyte, using a Ti plate as the cathode and a Ta plate as the anode, and depositing hydroxyapatite in the pores by electrochemical deposition;

[0014] (5) removing the photoresist to expose the tantalum coating, ultrasonic cleaning with deionized water, and drying.

[0015] Further, in step (1), the titanium alloy is a medical titanium alloy selected from one of Ti6Al4V, Ti-5Al-2.5Sn, and Ti-13Nb-13Zr.

[0016] Further, in step (2), the purity of the high-purity tantalum is 99.99%, and the process parameters of the multi-arc ion plating film are: vacuum degree 4-5 x 10 -3 Pa, high-purity argon gas, working gas pressure 0.6-1.0 Pa, arc current 150-200 A, substrate bias 700-800 V, deposition temperature 150-200℃, and deposition time 3-4 h.

[0017] Further, in step (4), the electrolyte composition is 3-4 x 10 -3 mol·L -1 Ca(NO3)2, 1-1.5 x 10 -3 mol·L -1 NaH2PO4, 0.2-0.5 mol·L-1 Sodium nitrate, pH 6.3-6.6; electrolyte temperature 130-150℃, current density 1.5-2.0 mA·cm -2 , deposition time 20-30 min.

[0018] A titanium alloy implant prepared by the above preparation method, comprising a titanium alloy body, a tantalum coating deposited on the surface of the titanium alloy body, and protruding hydroxyapatite micro-pillars formed on the surface of the tantalum coating.

[0019] Further, the tantalum coating is nanocrystalline, the grain size is 200-300 nm, mainly α-Ta phase, the content is greater than 98.5wt.%;The thickness is 400-500 nm.

[0020] Further, the height of the protruding hydroxyapatite micro-pillars is 4-5 μm.

[0021] Hydroxyapatite (Ca 10 The chemical composition of hydroxyapatite (Ca (PO4) 6 (OH) 2, HA) is very similar to the mineralized components of human bone tissue, and it is a kind of material with good biocompatibility and bioactivity, which is widely used in the field of implant materials;However, hydroxyapatite is a porous structure and has poor mechanical properties such as toughness and strength. Tantalum also has the advantages of good biocompatibility, chemical stability and corrosion resistance, and has excellent ductility, toughness and strength. The research in the field of implant materials is also relatively extensive. The present application combines the protection of tantalum coating on titanium alloy implant and the advantages of biocompatibility and bioactivity of hydroxyapatite, and gives the titanium alloy implant excellent comprehensive performance. The applicant also compared the direct electrochemical deposition of hydroxyapatite layer on the tantalum coating, and found that the titanium alloy implant obtained in performance is significantly inferior to the present application.

[0022] Tantalum mainly has α-Ta phase and β-Ta phase. Among them, α-Ta has stable bcc structure and excellent chemical properties, while β-Ta has the disadvantages of high brittleness and easy peeling. In the preparation process, α-Ta and β-Ta are easy to transform between phases, and the present application prepares a mixed phase of α-Ta and β-Ta, not a pure β-Ta phase. However, in order to obtain high content of α-Ta as much as possible, the deposition temperature of multi-arc ion plating is controlled at 150-200℃, which is beneficial to inhibit β-Ta and improve the formation of α-Ta. And by controlling the process parameters of multi-arc ion plating film, a tantalum coating mainly composed of α-Ta is finally obtained, and the content of α-Ta phase in the coating is greater than 98.5wt.%.

[0023] The application of a medical titanium alloy implant, the titanium alloy implant is applied to orthopedics, oral cavity.

[0024] The present application has the following advantages and beneficial effects relative to the prior art:

[0025] (1) By surface modification of the titanium alloy implant, a tantalum coating and protruding hydroxyapatite micro-pillars are prepared on the surface of the titanium alloy, thereby providing a preparation method for implant modification.

[0026] (2) The titanium alloy implant is endowed with the advantages of tantalum and hydroxyapatite, excellent corrosion resistance, biocompatibility, and excellent mechanical properties, thereby making up for the shortcomings of single materials and enabling the titanium alloy implant after surface modification to have more extensive applications. DETAILED DESCRIPTION

[0027] In order to more clearly, completely and comprehensively show the technical solutions, objectives and advantages of the present application, the present application is further described in detail below in combination with specific examples and comparative examples.

[0028] Note: In order to facilitate operation, the following examples and comparative examples use a titanium alloy plate as the substrate (size: 50x30x10mm).

[0029] Example 1

[0030] A preparation method of surface modification of a titanium alloy implant, comprising the following steps:

[0031] (1) Polishing the surface of the titanium alloy, followed by ultrasonic cleaning in ethanol and drying;

[0032] (2) Placing the titanium alloy in a multi-arc ion plating film device, using high-purity tantalum as the target material to deposit a tantalum coating on the surface of the titanium alloy;

[0033] (3) Coating photoresist on the surface of the titanium alloy, and then forming a micropore array on the surface of the tantalum coating by using photolithography technology, wherein the thickness of the photoresist is 2μm, the pore diameter is 1μm, and the interval is 10μm;

[0034] (4) Placing the titanium alloy in an electrolyte, using a Ti plate as the cathode and a Ta plate as the anode, and depositing hydroxyapatite in the pores by electrochemical deposition;

[0035] (5) Removing the photoresist to expose the tantalum coating, ultrasonic cleaning with deionized water, and drying.

[0036] The titanium alloy is Ti6Al4V;

[0037] In step (2), the purity of the high-purity tantalum is 99.99%, and the process parameters of the multi-arc ion plating film are as follows: vacuum degree 4x10 -3 Pa, high-purity argon is introduced, working gas pressure 0.6Pa, arc current 150A, substrate bias 700V, deposition temperature 150℃, and deposition time 3h;

[0038] The electrolyte composition in step (4) is 3x10 -3 mol·L -1 Calcium nitrate, 1x10 -3 mol·L -1 Sodium dihydrogen phosphate, 0.2 mol·L -1 Sodium nitrate, pH 6.6; electrolyte temperature 130℃, current density 1.5 mA·cm -2 , deposition time 20 min.

[0039] Example 2

[0040] A preparation method of surface modification of a titanium alloy implant, comprising the following steps:

[0041] (1) polishing the titanium alloy surface, then ultrasonic cleaning in ethanol and drying;

[0042] (2) placing the titanium alloy in a multi-arc ion plating film device, using high-purity tantalum as the target material, and depositing a tantalum coating on the titanium alloy surface;

[0043] (3) coating photoresist on the titanium alloy surface, and then forming a micropore array on the surface of the tantalum coating by using photolithography technology, wherein the thickness of the photoresist is 3 μm, the pore diameter is 2 μm, and the interval is 15 μm;

[0044] (4) placing the titanium alloy in an electrolyte, using a Ti plate as the cathode and a Ta plate as the anode, and depositing hydroxyapatite in the pores by electrochemical deposition;

[0045] (5) removing the photoresist to expose the tantalum coating, ultrasonic cleaning with deionized water, and drying;

[0046] The titanium alloy is Ti6Al4V;

[0047] In step (2), the purity of the high-purity tantalum is 99.99%, and the process parameters of the multi-arc ion plating film are: vacuum degree 5x10 -3 Pa, high-purity argon is introduced, working gas pressure 1.0 Pa, arc current 200 A, substrate bias 800 V, deposition temperature 200℃, and deposition time 4 h.

[0048] The electrolyte composition in step (4) is 4x10 -3 mol·L -1 Calcium nitrate, 1.5x10 -3 mol·L -1 Sodium dihydrogen phosphate, 0.5 mol·L -1 Sodium nitrate, pH 6.4; electrolyte temperature 150℃, current density 2.0 mA·cm -2 , deposition time 30 min.

[0049] Example 3

[0050] A preparation method of surface modification of a titanium alloy implant, comprising the following steps:

[0051] (1) polishing the surface of the titanium alloy, and then ultrasonic cleaning in ethanol and drying;

[0052] (2) placing the titanium alloy in a multi-arc ion plating film device, using high-purity tantalum as a target material to deposit a tantalum coating on the surface of the titanium alloy;

[0053] (3) coating photoresist on the surface of the titanium alloy, and then forming a micropore array on the surface of the tantalum coating by using a photolithography technology, wherein the thickness of the photoresist is 3 μm, the pore diameter is 1 μm, and the interval is 12 μm;

[0054] (4) placing the titanium alloy in an electrolyte, using a Ti plate as a cathode and a Ta plate as an anode to deposit hydroxyapatite in the pores by electrochemical deposition;

[0055] (5) removing the photoresist to expose the tantalum coating, ultrasonic cleaning with deionized water, and drying;

[0056] wherein the titanium alloy is Ti6Al4V;

[0057] In step (2), the purity of the high-purity tantalum is 99.99%, and the process parameters of the multi-arc ion plating film are: vacuum degree 4×10 -3 Pa, high-purity argon is introduced, working gas pressure 1.0 Pa, arc current 180 A, substrate bias 750 V, deposition temperature 180℃, and deposition time 3.5 h.

[0058] In step (4), the electrolyte composition is 3.5×10 -3 mol·L -1 -1 calcium nitrate, 1.2×10 -3 mol·L -1 -1 sodium dihydrogen phosphate, 0.3 mol·L -1 -1 sodium nitrate, pH 6.5; electrolyte temperature 140℃, current density 1.8 mA·cm -2 , and deposition time 25 min.

[0059] Comparative Example 1

[0060] A preparation method of surface modification of a titanium alloy implant, comprising the following steps:

[0061] (1) polishing the surface of the titanium alloy, and then ultrasonic cleaning in ethanol and drying;

[0062] (2) placing the titanium alloy in a multi-arc ion plating film device, using high-purity tantalum as a target material to deposit a tantalum coating on the surface of the titanium alloy;

[0063] (3) Put the titanium alloy into the electrolyte, take Ti plate as cathode and Ta plate as anode, and deposit hydroxyapatite in the pores by electrochemical deposition;

[0064] (4) Deionized water ultrasonic cleaning and drying.

[0065] The titanium alloy is Ti6Al4V;

[0066] In step (2), the purity of the high-purity tantalum is 99.99%, and the process parameters of the multi-arc ion plating film are as follows: vacuum degree 4x10 -3 Pa, high-purity argon is introduced, working gas pressure 1.0 Pa, arc current 180 A, substrate bias 750 V, deposition temperature 180℃, and deposition time 3.5 h.

[0067] In step (3), the electrolyte composition is 3.5x10 -3 mol·L -1 mol·L -3 mol·L -1 mol·L -1 NaNO3, pH 6.5; electrolyte temperature 140℃, current density 1.8 mA·cm -2 , and deposition time 25 min.

[0068] The titanium alloy implants prepared in Examples 1-3 and Comparative Example 1 are measured and characterized, and the test results show that the tantalum coating is a nanocrystalline structure; the specific data are recorded in Tables 1-2.

[0069] Table 1

[0070]

[0071] Table 2

[0072]

[0073] From the hardness and elastic modulus data, it can be seen that the hardness and elastic modulus of Comparative Example 1 are significantly lower than those of the present application; this is because the titanium alloy surface of Comparative Example 1 is entirely covered by hydroxyapatite, while the outer layer of Examples 1-3 not only has protruding hydroxyapatite micropillars, but also because the main area is a tantalum coating.

[0074] The self-corrosion potential is the steady-state potential measured in the absence of external voltage interference, and is an important indicator reflecting the corrosion tendency of the metal. According to the electrochemical theory, the more negative the corrosion potential value, the greater the tendency of the electrode to lose electrons, and the greater the corrosion tendency. The corrosion potential of Comparative Example 1 is as high as -204.9 mV, and the corrosion current density is as high as 5.62 μA·cm -2The corrosion resistance is far lower than the level of Example 3 of the present application. It is thus shown that covering the tantalum coating surface with the hydroxyapatite coating is not conducive to the improvement of the corrosion resistance of the titanium alloy implant.

[0075] The biological performance of the titanium alloy implant was evaluated by in vitro mineralization and in vitro cell activity. The in vitro mineralization test was carried out by soaking the titanium alloy implant in SBF solution for 14 days, and the mass increase before and after soaking was calculated. The in vitro cell activity test was carried out by inoculating the same amount of mouse embryonic osteoblasts MC3T3-E1 on the surface of the titanium alloy implant and placing it in the culture solution for 7 days, and the cell proliferation before and after culture was calculated. The specific data are recorded in Table 3.

[0076] Table 3

[0077]

[0078] From the data of in vitro mineralization and in vitro cell activity, it can be seen that the titanium alloy implants prepared in the examples and comparative examples have good biological performance. However, Comparative Example 1 shows better in vitro mineralization ability and in vitro cell activity. The reason for this is that the biological activity of hydroxyapatite is better than that of tantalum, and the overall coverage of the hydroxyapatite layer on the surface of the implant makes the contact area with the SBF solution and the culture solution larger, which is more conducive to the increase in mass and the proliferation of osteoblasts. However, according to the aforementioned mechanical test, the hydroxyapatite layer covered in Comparative Example 1 shields the tantalum coating, which significantly reduces the mechanical performance of the titanium alloy implant.

[0079] The above examples are merely examples for clearly illustrating the present application and are not intended to limit the embodiments; on the basis of the above description, other different forms of changes or variations can also be made by those skilled in the art. Here, it is not necessary and impossible to exhaust all the embodiments. The obvious changes or variations derived therefrom are still within the protection scope of the present application.

Claims

1. A method of producing a surface modification of a titanium alloy implant, characterized by, The method comprises the following steps: (1) polishing the surface of the titanium alloy, and then ultrasonic cleaning in ethanol and drying; (2) placing the titanium alloy in a multi-arc ion plating film equipment, and depositing a tantalum coating on the surface of the titanium alloy by using high-purity tantalum as a target material; (3) coating photoresist on the surface of the titanium alloy, and then forming a micropore array on the surface of the tantalum coating by using a photoetching technology, wherein the thickness of the photoresist is 2-3 microns, the pore diameter is 1-2 microns, and the interval is 10-15 microns; (4) placing the titanium alloy in an electrolyte, and depositing hydroxyapatite in the pores by electrochemical deposition by using a Ti plate as a cathode and a Ta plate as an anode; (5) removing the photoresist to expose the tantalum coating, ultrasonic cleaning in deionized water, and drying.

2. The method of claim 1, wherein: In step (2), the purity of the high-purity tantalum is 99.99%, and the process parameters of the multi-arc ion plating film are as follows: vacuum degree 4-5x10 -3 Pa, high-purity argon is introduced, working gas pressure 0.6-1.0 Pa, arc current 150-200 A, substrate bias 700-800 V, deposition temperature 150-200℃, and deposition time 3-4 h.

3. The method of claim 1, wherein: In step (4), the electrolyte composition is 3-4 × 10⁻⁶. -3 mol·L -1 Calcium nitrate, 1–1.5 × 10 -3 mol·L -1 Sodium dihydrogen phosphate, 0.2–0.5 mol·L⁻¹ -1 Sodium nitrate, pH 6.3–6.6; electrolyte temperature 130–150℃, current density 1.5–2.0 mA·cm⁻¹ -2 Deposition time: 20-30 min.

4. The method of claim 1, wherein: The titanium alloy is a medical titanium alloy, and is selected from one of Ti6Al4V, Ti-5Al-2.5Sn, and Ti-13Nb-13Zr.

5. A titanium alloy implant, characterized in that, The titanium alloy implant is prepared by the preparation method in any one of claims 1-4, and comprises a titanium alloy body, a tantalum coating deposited on the surface of the titanium alloy body, and protruding hydroxyapatite micropillars formed on the surface of the tantalum coating.

6. The titanium alloy implant of claim 5, wherein: The tantalum coating has a nanocrystalline structure, a grain size of 200-300 nm, is mainly in an alpha-Ta phase, and has a content of greater than 98.5 wt.%; and the thickness of the tantalum coating is 400-500 nm.

7. The titanium alloy implant of claim 5, wherein: The protruding hydroxyapatite micropillars have a height of 4-5 microns.

8. Use of a titanium alloy implant according to any one of claims 5-7, characterized in that: The titanium alloy implant is applied to orthopedics and oral surgery.

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