Porous titanium-based implant material surface calcium phosphorus coating and preparation method thereof

Abstract

The invention belongs to the technical field of implant materials, and discloses a porous titanium-based implant material surface calcium-phosphorus coating and a preparation method thereof. According to the method, a porous titanium-based implant material is used as a cathode, an annular platinum electrode is used as an anode, the cathode is located in the center of the annular electrode, a solution containing calcium and phosphorus is used as an electrolyte, biomimetic mineralization is carried out under the condition of pulse micro-potential, and the calcium-phosphorus coating is formed on the surface of the porous titanium-based implant material. According to the method, the biomimetic mineralization process of the surface of the beam structure in the porous titanium-based material is regulated and controlled by adopting the annular electrode and the weak electric field, migration of ions and ion groups in the porous scaffold is improved by adjusting the current of the annular electrode and combining the biomimetic mineralization process, and the porous titanium-based implant material uniformly covered with the calcium-phosphorus coating is obtained. The method is simple, and uniform covering of the calcium-phosphorus coating of the porous titanium-based implant material is achieved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of biomedical materials, and particularly relates to a porous titanium-based implant material surface calcium-phosphorus coating and a preparation method thereof. BACKGROUND

[0002] Titanium-based metal implant materials have excellent corrosion resistance, mechanical properties and good biocompatibility, and are widely used in various bone implant instruments. However, due to the fact that the elastic modulus of titanium implants is much higher than that of bone tissue, stress shielding is easily caused, resulting in bone implant failure. The solution to this problem is to reduce the Young's modulus of Ti-based biomaterials by introducing a porous structure, thereby minimizing or eliminating stress shielding of the tissue near the implant material, and ultimately prolonging the service life of the implant. In recent years, various technologies for manufacturing porous metals have been developed, including electron beam melting, directional water-cooled ice template manufacturing, and rapid prototyping three-dimensional printing. However, the micropores of the porous scaffold alone are not enough to enable the bone tissue to firmly combine with the implant surface, and therefore additional surface modification is required to enhance the bone integration performance of the porous titanium alloy.

[0003] It has been reported that excellent bone bonding can be achieved on ceramic implants by forming a biologically active calcium phosphate (CaP) apatite layer at the bone-implant interface. The apatite coating is conducive to rapid bone adaptation, fiberless tissue joint, shortened healing time, and increased tolerance to surgical inaccuracies. In addition, the formation of apatite in a biological environment also depends on the surface properties of the biomaterial.

[0004] However, due to the micron complex pore size structure of the porous titanium scaffold, it is difficult for powders and solutions to enter, and therefore traditional plasma spraying, sol-gel and biomimetic mineralization methods are difficult to construct a uniform biologically active apatite coating on the internal surface of the porous titanium material.

[0005] The present application uses a ring-shaped electrode and a weak electric field to regulate the biomimetic mineralization process of the internal structure surface of the porous titanium-based material, and by adjusting the ring-shaped electrode current and combining it with the biomimetic mineralization process, the migration of ions and ion groups in the porous scaffold is improved, and a porous titanium-based implant instrument with a uniform calcium-phosphorus coating is obtained. SUMMARY

[0006] To solve the shortcomings and deficiencies of the prior art, the present application aims to provide a porous titanium-based implant material surface calcium-phosphorus coating and a preparation method thereof. The present application uses a ring-shaped electrode and a weak electric field to regulate the biomimetic mineralization process of the internal structure surface of the porous titanium-based material, and by adjusting the ring-shaped electrode current and combining it with the biomimetic mineralization process, the migration of ions and ion groups in the porous scaffold is improved, and a porous titanium-based implant instrument with a uniform calcium-phosphorus coating is obtained.

[0007] The purpose of the present application is achieved by the following technical solutions:

[0008] A preparation method of a porous titanium-based implant material surface calcium-phosphorus coating, comprising the following steps:

[0009] 1) three-dimensional printing of porous titanium-based implant materials;

[0010] 2) acid washing and alkali washing of the porous titanium-based implant materials;

[0011] 3) biomimetic mineralization of the porous titanium-based implant materials under a pulse micro-potential of 0.9-2 mV, with the porous titanium-based implant materials as a cathode, a ring-shaped platinum electrode as an anode, and a biomimetic calcium-phosphorus solution as an electrolyte, to form a calcium-phosphorus coating on the surface of the porous titanium-based implant materials.

[0012] The biomimetic calcium-phosphorus solution is an SBF simulated body fluid with a concentration of 0.5-3 times.

[0013] The pulse micro-potential is 0.9-1.1 mV; the power source is a direct current pulse power source, the cycle is 1-10 s, and the duty cycle is 10-60%.

[0014] The biomimetic mineralization time is 2-6 days, preferably 3-5 days.

[0015] Preferably, the ring-shaped platinum electrode is a hollow cylinder, the inner diameter of which is greater than the largest horizontal transverse dimension of the porous titanium-based implant material, and the vertical height of the ring-shaped platinum electrode is greater than the vertical height of the porous titanium-based implant material.

[0016] The inner diameter of the ring-shaped platinum electrode is 2-4 times the largest horizontal transverse dimension of the porous titanium-based implant material, and the vertical height is 1.2-1.8 times the vertical height of the porous titanium-based implant material.

[0017] During the biomimetic mineralization, the porous titanium-based implant material is placed in the cavity of the ring-shaped platinum electrode, i.e., the cavity of the hollow cylinder.

[0018] The acid washing is performed using a mixed solution of hydrofluoric acid and nitric acid, and the alkali washing treatment is performed using a sodium hydroxide solution; the concentration of hydrofluoric acid in the acid solution during the acid washing is 0.1wt%-10wt%, and the concentration of nitric acid is 0.1wt%-10wt%. The concentration of sodium hydroxide in the alkali solution during the alkali washing is 0.1mol / L-10mol / L. The acid washing time is 1-10 min, and the alkali washing time is 10-60 min.

[0019] Compared with the prior art, the present application has the following advantages and beneficial effects:

[0020] The present application promotes the ion exchange between the ions in the simulated body fluid and the ions in the porous titanium through electrochemical migration by applying a weak potential, ensures the ion concentration around the internal lattice structure of the porous titanium, promotes the biomimetic mineralization process, and thus obtains a porous titanium-based implant device with a calcium-phosphorus coating uniformly covering the surface of the porous lattice. The preparation method of the present application is simple and efficient, and can be applied to the construction of a surface calcium-phosphorus coating of a personalized porous titanium-based implant device. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the reaction device with a ring electrode used in the present invention for pulse deposition of calcium phosphate coating on the surface of porous titanium-based implant material;

[0022] Figure 2 This is a top view of the cathode and anode in the reaction apparatus of the present invention;

[0023] Figure 3 The images show the morphology of the biomimetic mineralized calcium phosphate coating deposited on the surface of the TC4 porous titanium alloy material in Example 1 (a is an optical image, b is a scanning electron microscope image) and the energy dispersive spectroscopy (EDS) spectrum of the coating (c).

[0024] Figure 4 Figures (a) and (b) show the cross-sectional morphology of the biomimetic mineralized calcium phosphate coating deposited on the surface of the TC4 porous titanium alloy material prepared in Example 1 at different magnifications using scanning electron microscopes (SEM). In Figure b, the epoxy resin is derived from the embedding process, and the cross-section can only be observed after cutting and polishing. The pores in the titanium alloy material correspond to the spaces occupied by the epoxy resin in the figure. Figures (c) and (d) show the calcium phosphate composition distribution of the cross-section of the biomimetic mineralized calcium phosphate coating deposited on the surface of the porous titanium alloy material.

[0025] Figure 5 In Comparative Example 1, (a) and (b) are the surface morphology and energy dispersive spectroscopy (EDS) of the porous titanium alloy material after electrochemical-assisted biomimetic mineralization. Detailed Implementation

[0026] The present invention will be further described in detail below with reference to embodiments and accompanying drawings, but the embodiments of the present invention are not limited thereto. Unless otherwise specified in the embodiments of the present invention, conventional conditions or conditions recommended by the manufacturer shall apply. Raw materials, reagents, etc., used without specified manufacturers are all conventional products that can be purchased commercially.

[0027] A schematic diagram of the annular electrode reaction device used in this invention for pulse deposition of a calcium phosphate coating on the surface of porous titanium-based implant materials is shown below. Figure 1 As shown, the reaction apparatus includes a reaction tank, an anode, and a cathode. The anode is a ring-shaped platinum electrode, which is a hollow cylinder. The inner diameter of the ring-shaped platinum electrode is larger than the maximum horizontal dimension of the cathode (porous titanium-based implant material), and the vertical height of the ring-shaped platinum electrode is greater than the vertical height of the cathode (porous titanium-based implant material). Preferably, the inner diameter of the ring-shaped platinum electrode is 2 to 4 times the maximum horizontal dimension of the porous titanium-based implant material, and the vertical height is 1.2 to 1.8 times the vertical height of the porous titanium-based implant material. The cathode is placed in the cavity of the anode cylinder. The anode and cathode are located in the reaction tank and connected to a power source via wires.

[0028] Figure 2 This is a top view of the cathode and anode in the reaction apparatus of the present invention.

[0029] Example 1

[0030] A method for preparing a calcium phosphate coating on the surface of a porous titanium-based implantable device includes the following steps:

[0031] (1) Using 3D printing technology, porous TC4 titanium alloy material (pore size 200-1000μm) is prepared and then subjected to acid and alkali cleaning in a mixture of hydrofluoric acid and nitric acid (the concentration of hydrofluoric acid in the mixture is 0.1wt%, the concentration of nitric acid is 0.1wt%, the treatment time of the mixture is 3min) and sodium hydroxide solution (concentration is 1mol / L, treatment time is 10min). The 3D printed porous TC4 titanium alloy material is a porous titanium-based implant material.

[0032] (2) A porous TC4 titanium alloy material was used as the cathode, which was placed in the center of the reaction cell. A ring-shaped platinum electrode was used as the anode, with a diameter (inner diameter) three times the lateral dimension of the porous titanium-based implant material and a height 1.5 times the vertical dimension of the porous titanium-based implant material. The cathode was located in the ring of the anode, and the electrolyte was SBF simulated body fluid (Na₂S₃). + 142.0mM,K + 5.0mM, Ca 2+ 2.5mM, Mg 2+ 1.5mM, Cl - 147.8mM, HCO3 - 4.2mM, HPO4 2- 1.0mM, SO4 2- Biomimetic mineralization was carried out under pulsed micropotential conditions (0.5mM), with a pulse voltage of 1mV, a pulse period of 1s, a constant temperature of 37℃, and a reaction time of 5d.

[0033] (3) The coating sample obtained by biomimetic mineralization is washed with deionized water and vacuum dried to obtain a porous titanium-based implantable device with a uniform calcium phosphate coating on a microporous beam.

[0034] Example 2

[0035] A method for preparing a calcium phosphate coating on the surface of a porous titanium-based implantable device includes the following steps:

[0036] (1) Porous TC4 titanium alloy material was prepared by using three-dimensional printing technology. The porous TC4 titanium alloy material was then cleaned by acid and alkali cleaning in sequence with a mixed solution of hydrofluoric acid and nitric acid and sodium hydroxide solution.

[0037] (2) A porous TC4 titanium alloy material was used as the cathode, which was placed in the center of the reaction cell. A ring platinum electrode was used as the anode, with a diameter twice the lateral dimension of the porous titanium-based implant and a height 1.5 times the vertical dimension of the porous titanium-based implant. The electrolyte was SBF simulated body fluid. Under pulsed micropotential conditions, biomimetic mineralization was carried out. The pulse voltage was 1mV, the pulse period was 1S, the reaction temperature was constant at 37℃, and the reaction time was 5d.

[0038] (3) The coating sample obtained by biomimetic mineralization is washed with deionized water and vacuum dried to obtain a porous titanium-based implantable device with a uniform calcium phosphate coating on a microporous beam.

[0039] Example 3

[0040] A method for preparing a calcium phosphate coating on the surface of a porous titanium-based implantable device includes the following steps:

[0041] (1) Porous TC4 titanium alloy material was prepared by using three-dimensional printing technology. The porous TC4 titanium alloy material was then cleaned by acid and alkali cleaning in sequence with a mixed solution of hydrofluoric acid and nitric acid and sodium hydroxide solution.

[0042] (2) A porous TC4 titanium alloy material was used as the cathode, which was placed in the center of the reaction cell. A ring platinum electrode was used as the anode, with a diameter of 3 times the transverse dimension of the porous titanium-based implant and a height of 1.5 times the vertical dimension of the porous titanium-based implant. The electrolyte was 2SBF, a simulated body fluid with a concentration of 2 times the ion concentration. Biomimetic mineralization was carried out under pulsed micropotential conditions. The pulse voltage was 1mV, the pulse period was 1S, the reaction temperature was constant at 37℃, and the reaction time was 3d.

[0043] (3) The coating sample obtained by biomimetic mineralization is washed with deionized water and vacuum dried to obtain a porous titanium-based implant device with a uniform calcium phosphate coating. Using 2SBF solution can shorten the coating preparation time.

[0044] Example 4

[0045] A method for preparing a calcium phosphate coating on the surface of a porous titanium-based implantable device includes the following steps:

[0046] (1) Porous TC4 titanium alloy material was prepared by using three-dimensional printing technology. The porous TC4 titanium alloy material was then cleaned by acid and alkali cleaning in sequence with a mixed solution of hydrofluoric acid and nitric acid and sodium hydroxide solution.

[0047] (2) A porous TC4 titanium alloy material was used as the cathode, which was placed in the center of the reaction cell. A ring platinum electrode was used as the anode, with a diameter of 3 times the transverse dimension of the porous titanium-based implant and a height of 1.5 times the vertical dimension of the porous titanium-based implant. The electrolyte was SBF simulated body fluid. Under pulsed micropotential conditions, biomimetic mineralization was carried out. The pulse voltage was 2mV, the pulse period was 1S, the reaction temperature was constant at 37℃, and the reaction time was 5d.

[0048] (3) The coating sample obtained by biomimetic mineralization is washed with deionized water and vacuum dried to obtain a porous titanium-based implantable device with a uniform calcium phosphate coating on a microporous beam.

[0049] Example 5

[0050] A method for preparing a calcium phosphate coating on the surface of a porous titanium-based implantable device includes the following steps:

[0051] (1) Porous TA4 titanium alloy material was prepared by using three-dimensional printing technology. The porous TA4 titanium alloy material was then cleaned by acid and alkali cleaning in sequence with a mixed solution of hydrofluoric acid and nitric acid and sodium hydroxide solution.

[0052] (2) A porous TA4 titanium alloy material was used as the cathode, which was placed in the center of the reaction cell. A ring platinum electrode was used as the anode, with a diameter of 3 times the transverse dimension of the porous titanium-based implantable device and a height of 1.5 times the vertical dimension of the porous titanium-based implantable device. The electrolyte was SBF simulated body fluid. Under pulsed micropotential conditions, biomimetic mineralization was carried out. The pulse voltage was 1mV, the pulse period was 1S, the reaction temperature was constant at 37℃, and the reaction time was 5d.

[0053] (3) The coating sample obtained by biomimetic mineralization is washed with deionized water and vacuum dried to obtain a porous titanium-based implantable device with a uniform calcium phosphate coating on a microporous beam.

[0054] Comparative Example 1

[0055] A method for preparing a calcium phosphate coating on the surface of a porous titanium-based implantable device includes the following steps:

[0056] (1) Porous TC4 titanium alloy material was prepared by using three-dimensional printing technology. The porous TC4 titanium alloy material was then cleaned by acid and alkali cleaning in sequence with a mixed solution of hydrofluoric acid and nitric acid and sodium hydroxide solution.

[0057] (2) A porous TC4 titanium alloy material was used as the cathode, which was placed in the center of the reaction cell. A ring platinum electrode was used as the anode, with a diameter of 3 times the transverse dimension of the porous titanium-based implant and a height of 1.5 times the vertical dimension of the porous titanium-based implant. The electrolyte was SBF simulated body fluid. Under pulsed micropotential conditions, biomimetic mineralization was carried out. The pulse voltage was 100mV, the pulse period was 1S, the reaction temperature was constant at 37℃, and the reaction time was 5d.

[0058] It will be impossible to obtain a biomimetic mineralized calcium phosphate coating.

[0059] Comparative Example 2

[0060] The platinum electrode was sheet-shaped, and other conditions were the same as in Example 1.

[0061] It is impossible to obtain a uniform biomimetic mineralized calcium phosphate coating.

[0062] Figure 3 The images show the morphology and energy dispersive spectroscopy (EDS) of the biomimetic mineralized calcium phosphate coating deposited on the surface of the TC4 porous titanium alloy material in Example 1; optical image (a); scanning electron microscope (SEM) morphology image (b); and (c) EDS energy dispersive spectroscopy of the coating.

[0063] Figure 4 Figures (a) and (b) show the cross-sectional scanning electron microscope (SEM) images of the biomimetic mineralized calcium phosphate coating deposited on the surface of the TC4 porous titanium alloy material prepared in Example 1 at different magnifications. In Figure b, the epoxy resin is from the embedding process, and the cross-section can only be observed after cutting and polishing. The pores in the titanium alloy material correspond to the space occupied by the epoxy resin in the figure. Figures (c) and (d) show the calcium phosphate composition distribution of the cross-section of the biomimetic mineralized calcium phosphate coating deposited on the surface of the porous titanium alloy material.

[0064] Figure 5 In Figures (a) and (b), the electrochemical-assisted simulations of the porous titanium alloy material surface in Comparative Example 1 are shown respectively.

[0065] Surface morphology and energy dispersive spectroscopy (EDS) images after mineralization.

[0066] Examples 2-5 have similar effects to Example 1, obtaining a uniform biomimetic mineralized calcium phosphate coating.

Claims

1. A method for preparing a calcium phosphate coating on the surface of a porous titanium-based implant material, characterized in that: Includes the following steps: 1) Three-dimensional printing to prepare porous titanium-based implant materials; 2) The porous titanium-based implant material is subjected to acid washing and alkali washing treatment; 3) A porous titanium-based implant material is used as the cathode, and a ring platinum electrode is used as the anode. The cathode is located in the center of the ring electrode. A solution containing calcium and phosphorus is used as the electrolyte. Under pulsed micropotential conditions, biomimetic mineralization is carried out, and a calcium-phosphorus coating is formed on the surface of the porous titanium-based implant material. The solution containing calcium and phosphorus is a biomimetic calcium-phosphorus solution. The conditions for biomimetic mineralization are: pulse potential: 0.9-2mV, and the time for biomimetic mineralization is 2-6 days; The annular platinum electrode is a hollow cylinder. The inner diameter of the annular platinum electrode is 2 to 4 times the maximum horizontal dimension of the porous titanium-based implant material, and the vertical height is 1.2 to 1.8 times the vertical height of the porous titanium-based implant material.

2. The method for preparing the calcium phosphate coating on the surface of the porous titanium-based implant material according to claim 1, characterized in that: The solution containing calcium and phosphorus is a 0.5 to 3 times concentration of SBF-simulated body fluid; The pulsed micropotential is 1mV; the power supply is a DC pulse power supply with a period of 1s-10s and a duty cycle of 10-60%.

3. The method for preparing the calcium phosphate coating on the surface of the porous titanium-based implant material according to claim 1, characterized in that: The biomimetic mineralization process takes 3-5 days.

4. The method for preparing the calcium phosphate coating on the surface of the porous titanium-based implant material according to claim 1, characterized in that: The reaction temperature for the biomimetic mineralization is 37℃; The porous titanium-based implantable device material is one of TA3, TA4, and TC4 pure titanium and titanium alloy materials.

5. The method for preparing the calcium phosphate coating on the surface of the porous titanium-based implant material according to claim 1, characterized in that: The pickling is performed using a mixed solution of hydrofluoric acid and nitric acid; the alkaline washing treatment refers to treatment using a sodium hydroxide solution; during pickling, the concentration of hydrofluoric acid in the acid solution is 0.1wt%-10wt%, and the concentration of nitric acid is 0.1wt%-10wt%. During alkaline washing, the concentration of sodium hydroxide in the alkaline solution is 0.1 mol / L-10 mol / L; The pickling time is 1-10 minutes; the alkaline washing time is 10-60 minutes.

6. A calcium phosphate coating on the surface of a porous titanium-based implant material obtained by the preparation method according to any one of claims 1 to 5, characterized in that: The implant material is a bone implant material.

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