Titanium-molybdenum alloy multistage bionic structure and preparation method thereof

Abstract

The invention discloses a titanium-molybdenum alloy multi-stage bionic structure and a preparation method thereof, and belongs to the technical field of biomedicine, the titanium-molybdenum alloy multi-stage bionic structure comprises bionic units distributed in an array mode, nanotube structures are constructed on the surfaces of porous titanium-molybdenum alloy frames of the bionic units, and functional peptides are modified on the surfaces of the nanotube structures. According to the titanium-molybdenum alloy multistage bionic structure and the preparation method thereof, the problem of mechanical matching of the titanium-molybdenum alloy is solved through 3D printing of the porous titanium-molybdenum alloy sample, the problem of low biocompatibility of the porous titanium-molybdenum alloy sample is solved through anodic oxidation, and the functions of osseointegration and the like are achieved by adding the functional molecule peptide to the surface; according to the titanium-molybdenum alloy, adhesion and proliferation of bone cells are improved through biophysical stimulation (topological structure effect) and biochemical stimulation (osteogenic factor mimic peptide induction), three-level structure interaction is achieved, the combination process of bone implantation is effectively adjusted, and support is provided for improvement of the biocompatibility of the titanium-molybdenum alloy and further application of the titanium-molybdenum alloy in the field of biological medicine.

Description

Technical Field

[0001] The invention relates to the field of biomedical technology, and in particular to a titanium-molybdenum alloy multi-level bionic structure and a preparation method thereof. Background Art

[0002] In today's society, with the improvement of people's quality of life and the development of population aging, people's demand for orthopedic implants is increasing. At present, the most commonly used metal bone implant is Ti6Al4V. Although the performance of this type of material has reached the level of clinical application, aluminum (Al) and vanadium (V) have biological toxicity for long-term implants, causing secondary damage to patients. Mo in titanium-molybdenum alloy is a trace element of the human body. It is not only of great significance to nutrition and metabolism, but also has important physiological functions in the human body. However, the elastic modulus of titanium-molybdenum alloy is still somewhat different from that of human bone, and the surface biocompatibility needs to be improved. Summary of the invention

[0003] The purpose of the present invention is to provide a titanium-molybdenum alloy multi-level bionic structure and a preparation method thereof, so as to solve the problems of mechanical matching and biocompatibility of current implants.

[0004] To achieve the above objectives, the present invention provides a titanium-molybdenum alloy multi-level bionic structure, comprising array-distributed bionic units, wherein a nanotube structure is constructed on the surface of the porous titanium-molybdenum alloy framework of the bionic unit, and the surface of the nanotube structure is modified with functional peptides.

[0005] The present invention provides a method for preparing a titanium-molybdenum alloy multi-level bionic structure, comprising the following steps: S1. Preparation of porous titanium-molybdenum alloy stent by 3D printing; S2, preparing titanium dioxide nanotube arrays on the surface of porous titanium-molybdenum alloy stents by anodization; S3. The surface of the titanium dioxide nanotube array is modified with a functional molecular peptide to prepare a titanium-molybdenum alloy multi-level bionic structure.

[0006] Preferably, the unit cell size of the titanium-molybdenum alloy in S1 is 1-8 mm, the slice thickness is 0.13-0.32 mm, and the porosity is 60-90%.

[0007] Preferably, the unit cell size of the titanium-molybdenum alloy in S1 is 2-5 mm, and the porosity is 65-85%.

[0008] Preferably, the specific operation of S2 is: At a constant temperature of 20°C, graphite paper and a porous titanium-molybdenum alloy support were used as cathode and anode, respectively, placed in an electrolyte solution, and stirred at a constant speed magnetically to perform anodization, and the electrolyte was kept in a state of constant and constant magnetic stirring; After anodization, the samples were taken out, rinsed with deionized water and then fully dried; The sample was heat treated in a tube furnace, kept warm again, and cooled to room temperature along with the furnace to obtain a titanium dioxide nanotube array.

[0009] Preferably, the electrolyte solution in S2 is a F-containing solution, the anodic oxidation voltage is 10-80 V, and the oxidation time is 1-6 h.

[0010] Preferably, the electrolyte solution in S2 contains 0.1%-0.5wt% NH4HF2 and 5% vol water.

[0011] Preferably, the temperature of the heat treatment in the tube furnace in S2 is 400-500°C, and the heating rate is 1-5°C·min -1 , the insulation time is 1-5h.

[0012] Compared with Ti6Al4V alloy, titanium-molybdenum alloy does not contain aluminum, which avoids the formation of aluminum oxides during the oxidation process. The formation of aluminum oxides may affect the properties and thickness of the oxide film, and the release of aluminum is believed to cause toxic reactions, thereby affecting biocompatibility. Molybdenum, as a necessary trace element for the human body, has good biocompatibility and does not produce toxic reactions. At the same time, it can effectively promote the formation of a uniform oxide film on the surface of titanium-based alloys, improve the density of the oxide film, and enhance corrosion resistance.

[0013] A titanium-molybdenum alloy multi-level bionic structure and its preparation method, which ultimately obtains the tertiary structure forming mechanism of "functional peptide-nanotube array-porous topological structure", improves the mechanical matching problem of titanium-molybdenum alloy by 3D printing porous titanium-molybdenum alloy samples, improves the low biocompatibility of 3D printed porous titanium-molybdenum alloy samples by anodizing, and adds functional molecular peptides to the surface to promote osteogenic differentiation. The adhesion and proliferation of bone cells are improved by biophysical stimulation (topological structure effect) and biochemical stimulation (osteoblastic factor mimetic peptide induction), and the tertiary structure interacts to effectively regulate the binding process of bone implants. It provides support for improving the biocompatibility of titanium-molybdenum alloys and their further application in the field of biomedicine.

[0014] Therefore, the present invention adopts the above-mentioned titanium-molybdenum alloy multi-level bionic structure and its preparation method, which has the following beneficial effects: (1) Titanium-molybdenum alloy is selected as the substrate, and the design of titanium alloy elements is optimized to improve the biocompatibility of biomedical titanium alloy materials. While solving the side effects caused by long-term implantation, the addition of Mo elements can stabilize the β phase and significantly reduce the elastic modulus of titanium alloys. It also plays an important role in grain refinement, strength and wear resistance. (2) Design of multi-level bionic structure of titanium-molybdenum alloy Through the multi-level bionic interface interaction of "functional peptide-nanotube array-porous topological framework", the multi-level bionic structure of titanium-molybdenum alloy solves stress matching by optimizing the composition texture, pore size / porosity, etc. of 3D printed porous titanium alloy materials; using anodization process to prepare ordered nanotube arrays on the surface of titanium alloy to reduce host response and improve its biocompatibility; modifying biomolecular peptides on the surface of micro-nano topological structure by self-assembly method to promote bone induction and differentiation, establish a synergistic improvement mechanism of mechanical matching and biocompatibility, and finally synthesize a new type of bone-mimicking material with high mechanical matching and biocompatibility. The three-level structure interacts with each other, giving cells active biophysical and biochemical stimulation, thereby promoting the adhesion and growth of bone cells.

[0015] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of a 3D printing structure of an embodiment of a method for preparing a titanium-molybdenum alloy multi-level bionic structure of the present invention; Figure 2 This is a SEM image of the nanotube morphology on the surface after anodization in an embodiment of a method for preparing a titanium-molybdenum alloy multi-level bionic structure of the present invention; Figure 3 This is a graph showing the experimental results of the surface contact angle test of a titanium-molybdenum alloy multi-level bionic structure prepared in an embodiment of a method for preparing a titanium-molybdenum alloy multi-level bionic structure of the present invention. DETAILED DESCRIPTION

[0017] The technical solution of the present invention is further described below through the accompanying drawings and embodiments.

[0018] Unless otherwise defined, technical or scientific terms used in the present invention shall have the common meanings understood by one having ordinary skills in the field to which the present invention belongs.

[0019] Example The present invention provides a titanium-molybdenum alloy multi-level bionic structure, comprising bionic units distributed in an array, wherein a nanotube structure is constructed on the surface of a porous titanium-molybdenum alloy framework of the bionic unit, and a functional peptide is modified on the surface of the nanotube structure. The titanium-molybdenum alloy multi-level bionic structure is a tertiary structure of "functional peptide-nanotube array-porous topological framework".

[0020] The preparation method comprises the following steps: S1. Prepare porous titanium-molybdenum alloy stents, regulate the elastic modulus of the material through macroscopic structure, and solve the problem of mechanical matching.

[0021] S11. Use CAD, 3DMaxs, Solidworks and other software to design a titanium-molybdenum alloy with a porous structure with micron-sized pores. The structures can be BCC, FCC, rhombic dodecahedron, TPMS and other structures, among which TPMS is the optimal structure.

[0022] The unit cell size of the titanium-molybdenum alloy is 1-8 mm, the slice thickness is 0.13-0.32 mm, the porosity is 60-90%, and the particle size of the titanium-molybdenum alloy powder is 0-80 μm. Preferably, the unit cell size of the titanium-molybdenum alloy is 2-5 mm, the porosity is 65-85%, and the particle size of the titanium-molybdenum alloy powder is 15-53 μm.

[0023] S12. After designing the structure, import the structure into magics software for typesetting, and pour the titanium-molybdenum alloy powder into the powder bin of the 3D printing equipment. The 3D printing methods include SLM, DLP, EBM, FDM and other methods, among which SLM is the best printing method. Use stainless steel as the substrate, preheat 50-100℃, laser power 150-200W, scanning speed 1000-1500mm / s, powder thickness 50-80μm, and prepare a porous titanium-molybdenum alloy bracket.

[0024] S2. Titanium dioxide nanotube arrays were prepared on the surface of porous titanium-molybdenum alloy stents by electrochemical method, and the biocompatibility of the alloy was improved by constructing nanostructures.

[0025] S21. Surface pretreatment of porous titanium-molybdenum alloy: first, electrochemical polishing of porous titanium-molybdenum alloy stent, using porous titanium-molybdenum alloy stent sample as anode and steel as cathode, immersing the porous titanium-molybdenum alloy stent sample at the anode into electrochemical polishing solution, turning on the power of the electrochemical workstation, and setting the current density to 40-60A / dm 2 , polishing time is 150-200s.

[0026] Preparation of electrochemical polishing solution: Mix 10 mol / L oxalic acid, 5.3 mol / L ethylene glycol, 2.7 mol / L ammonium fluoride and 1.1 mol / L oxalic acid in water, and stir evenly with a magnetic stirrer.

[0027] S22. Prepare titanium dioxide nanotubes by electrochemical method: at a constant temperature of 20°C, use graphite paper and porous titanium-molybdenum alloy support as cathode and anode, respectively, place in electrolyte solution, and stir magnetically at a constant speed, perform anodic oxidation, and keep the electrolyte in a state of constant magnetic stirring at a constant speed, the anodic oxidation voltage is 10-80V, and the oxidation time is 1-6h. The electrolyte solution is a F-containing solution, preferably an electrolyte solution containing 0.1%-0.5wt% NH4HF2 and 5% vol water.

[0028] After anodization, the samples were taken out, rinsed with deionized water and dried thoroughly, and then heat treated in a tube furnace at 400-500 °C with a heating rate of 1-5 °C·min -1 , and keep warm again for 1-5h, and cool to room temperature with the furnace to obtain a titanium dioxide nanotube array.

[0029] S3. The surface of the titanium dioxide nanotube array is modified with a functional molecular peptide to prepare a titanium-molybdenum alloy multi-level bionic structure.

[0030] The present invention adopts the above-mentioned titanium-molybdenum alloy multi-level bionic structure and its preparation method, and finally prepares a three-level bionic structure of "functional peptide-nanotube array-porous topological framework". Its mechanism is to improve the mechanical matching problem of titanium-molybdenum alloy by 3D printing porous titanium-molybdenum alloy samples, improve the low biocompatibility of 3D printed porous titanium-molybdenum alloy samples by anodizing, and add functional molecular peptides to the surface to promote osteogenic differentiation. The adhesion and proliferation of bone cells are improved by biophysical stimulation (topological structure effect) and biochemical stimulation (osteoblastic factor mimetic peptide induction), and the three-level structure interacts to effectively regulate the binding process of bone implants, providing support for improving the biocompatibility of titanium-molybdenum alloys and their further application in the field of biomedicine.

[0031] Embodiment 1 The preparation process of titanium-molybdenum alloy multi-level bionic structure is as follows: Step 1: 3D printed titanium-molybdenum alloy structure design: Use CAD, 3DMaxs, Solidworks and other software to design a titanium-molybdenum alloy with a unit cell size of 2.5mm and an overall arrangement of a TPMS structure of 10*10*15mm. The slice thickness of the structure is 0.13mm and the porosity is 85%. Figure 1 shown.

[0032] Preparation of 3D printed titanium-molybdenum alloy: The above structure was imported into magics software for typesetting, and titanium-molybdenum alloy powder with a particle size of 15-53μm was poured into the powder bin of the SLM molding equipment. A stainless steel plate was used as the substrate, preheated to 100°C, the laser power was 175W, the scanning speed was 1100mm / s, and the powder thickness was 60μm to prepare a porous titanium-molybdenum alloy bracket.

[0033] Step 2: Construction of 3D printed titanium dioxide nanotube array on the surface of porous titanium alloy: Prepare nanotube structure on the surface of porous titanium-molybdenum alloy stent by electrochemical method.

[0034] Surface pretreatment of porous titanium-molybdenum alloy: First, the porous titanium-molybdenum alloy is electrochemically polished. The anode is a porous titanium-molybdenum alloy sample, and the cathode is a steel material. The porous titanium-molybdenum alloy sample of the anode is immersed in the electrochemical polishing solution, and the power of the electrochemical workstation is turned on, and the current density is set to 5000A / m2 , polishing time is 180s.

[0035] Surface anodization treatment: Titanium dioxide nanotubes were prepared by constant voltage anodization. At a constant temperature of 20°C, graphite paper and porous titanium-molybdenum alloy brackets were used as cathodes and anodes, respectively, and the porous titanium-molybdenum alloy brackets were immersed in an anodized electrolyte solution. The electrolyte solution contained 0.05 mol of NH4HF2, 30 ml of water and 1 L of ethylene glycol solution, and was magnetically stirred at a constant speed for 1 hour. During the anodization process, the voltage was 40 V, the oxidation time was 2 hours, and the electrolyte was kept in a state of constant magnetic stirring at a constant speed to maintain a uniform electrolyte concentration and prevent the occurrence of bubbles at the anode that hinder the reaction. After anodization, the anode was removed, rinsed with deionized water to remove the residual electrolyte on the surface, and then fully dried to obtain titanium dioxide nanotubes.

[0036] Post-treatment: The porous titanium-molybdenum alloy sample after anodization needs to undergo phase transformation. The sample is heat treated at 450°C in a tube furnace with a heating rate of 2°C·min -1 , keep warm for 2 hours, and cool to room temperature. Then, titanium dioxide nanotube arrays can be obtained. Figure 2 As shown, this SEM image shows the ordered nanotube array formed after anodization, indicating that the anodization process successfully formed a regular nanostructure on the surface of the material.

[0037] Step 3: Modify the surface of the titanium dioxide nanotube array with a functional molecular peptide to prepare a titanium-molybdenum alloy multi-level bionic structure.

[0038] Figure 3 This is the result of the surface contact angle test experiment after the preparation of the titanium-molybdenum alloy multi-level bionic structure. The figure shows that the surface of the titanium-molybdenum alloy multi-level bionic structure is super hydrophilic. This super hydrophilic surface has important application value in biomedicine, materials science and other fields.

[0039] Embodiment 2 The operation of this embodiment is the same as that of the first embodiment, except that: in the structural design of step 1, the slice thickness of the titanium-molybdenum alloy of the TPMS structure is 0.17 mm and the porosity is 80%.

[0040] Embodiment 3 The operation of this embodiment is the same as that of the first embodiment, except that: in the structural design of step 1, the slice thickness of the titanium-molybdenum alloy of the TPMS structure is 0.22 mm, and the porosity is 75%.

[0041] Embodiment 4 The operation of this embodiment is the same as that of the first embodiment, except that the structural design in step one can be designed through CT scanning and finite element analysis of human bones to design a structure similar to human bones, so as to be customized for different patients.

[0042] Embodiment 5 The operation of this embodiment is the same as that of the first embodiment, except that the anodizing voltage in step 2 is 20V.

[0043] Embodiment 6 The operation of this embodiment is the same as that of the first embodiment, except that the anodizing voltage in step 2 is 60V.

[0044] Embodiment 7 The operation of this embodiment is the same as that of the first embodiment, except that the anodizing time in step 2 is 4 hours.

[0045] Embodiment 8 The operation of this embodiment is the same as that of the first embodiment, except that the anodizing time in step 2 is 6 hours.

[0046] Therefore, the present invention adopts the above-mentioned titanium-molybdenum alloy multi-level bionic structure and its preparation method, the multi-level bionic structure of titanium-molybdenum alloy, solves stress matching by optimizing the component texture, pore size / porosity, etc. of 3D printed porous titanium alloy materials, and uses anodization process to prepare ordered nanotube arrays on the surface of titanium alloy to reduce host response and improve its biocompatibility. The biomolecular peptides are modified on the surface of the micro-nano topological structure by a self-assembly method to promote bone induction and differentiation, establish a synergistic improvement mechanism of mechanical matching and biocompatibility, and finally synthesize a new bone-mimicking material with high mechanical matching and biocompatibility.

[0047] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.

Claims

1. A titanium-molybdenum alloy multi-level bionic structure, characterized in that: The invention comprises bionic units distributed in an array, wherein a nanotube structure is constructed on the surface of a porous titanium-molybdenum alloy framework of the bionic unit, and a functional peptide is modified on the surface of the nanotube structure.

2. A method for preparing the titanium-molybdenum alloy multi-level bionic structure according to claim 1, characterized in that: The following steps are involved: S1. Preparation of porous titanium-molybdenum alloy stent by 3D printing; S2, preparing titanium dioxide nanotube arrays on the surface of porous titanium-molybdenum alloy stents by anodizing; S3. The surface of the titanium dioxide nanotube array is modified with a functional molecular peptide to prepare a titanium-molybdenum alloy multi-level bionic structure.

3. The method for preparing a titanium-molybdenum alloy multi-level bionic structure according to claim 2, characterized in that: The unit cell size of the titanium-molybdenum alloy in S1 is 1-8 mm, the slice thickness is 0.13-0.32 mm, and the porosity is 60-90%.

4. The method for preparing a titanium-molybdenum alloy multi-level bionic structure according to claim 2, characterized in that: The unit cell size of the titanium-molybdenum alloy in S1 is 2-5 mm and the porosity is 65-85%.

5. The method for preparing a titanium-molybdenum alloy multi-level bionic structure according to claim 2, characterized in that: The specific operations of S2 are: At a constant temperature of 20°C, graphite paper and a porous titanium-molybdenum alloy support were used as cathode and anode, respectively, placed in an electrolyte solution, and stirred at a constant speed magnetically to perform anodization, and the electrolyte was kept in a state of constant and constant magnetic stirring; After anodization, the samples were taken out, rinsed with deionized water and then fully dried; The sample was heat treated in a tube furnace, kept warm again, and cooled to room temperature along with the furnace to obtain a titanium dioxide nanotube array.

6. The method for preparing a titanium-molybdenum alloy multi-level bionic structure according to claim 5, characterized in that: The electrolyte solution in S2 is a F-containing solution, the anodic oxidation voltage is 10-80V, and the oxidation time is 1-6h.

7. The method for preparing a titanium-molybdenum alloy multi-level bionic structure according to claim 6, characterized in that: The electrolyte solution in S2 contains 0.1%-0.5wt% NH4HF2 and 5% vol water.

8. The method for preparing a titanium-molybdenum alloy multi-level bionic structure according to claim 5, characterized in that: The heat treatment temperature in the S2 tube furnace is 400-500℃, and the heating rate is 1-5℃·min -1 , the insulation time is 1-5h.

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