Medical nano-hydroxyapatite coated porous tantalum implant material and preparation method thereof

Abstract

This invention discloses a medical nano-hydroxyapatite coated porous tantalum implant material and its preparation method. The preparation method includes: etching a graphite carbon skeleton with HCl solution, followed by washing and drying to obtain a porous carbon skeleton, which is then placed in a vapor deposition reaction chamber; passing a treatment gas and a reducing gas through the reaction chamber to perform vapor deposition, thereby depositing a tantalum coating on the surface of the porous carbon skeleton to obtain a porous tantalum metal scaffold; the treatment gas includes a tantalum source and a carrier gas; dissolving a calcium source, a phosphorus source, and sodium chloride in deionized water to obtain a mixed solution, adjusting the pH to 4.3 to obtain an electrolyte; using the porous tantalum metal scaffold as the working electrode and graphite as the counter electrode, electrochemical deposition is performed in the electrolyte using a pulsed current mode to deposit a nano-hydroxyapatite coating on the surface of the porous tantalum metal scaffold, resulting in a medical nano-hydroxyapatite coated porous tantalum implant material with a high porosity >70% and an elastic modulus <30 GPa.

Description

Technical Field

[0001] This invention relates to the field of medical materials technology, and more specifically, to a medical nano-hydroxyapatite coated porous tantalum implant material and its preparation method. Background Technology

[0002] Large bone defects, i.e., defects larger than the critical size (CSD), lack the ability to regenerate on their own and often require surgical intervention. Among various modern therapies, autologous bone grafting has proven to be very effective in repairing bone defects; however, autologous grafting has drawbacks such as donor site complications and limited supply.

[0003] Synthetic bone substitutes are typically used in the form of porous scaffold structures, providing an effective alternative for repairing bone defects. Among numerous medical materials, tantalum (Ta) is widely used in surgical sutures, bone fixation materials, bone implants, vascular stent coatings, and imaging contrast agents due to its excellent biocompatibility and superior physicochemical and biological properties. In 1994, Kaplan successfully obtained a porous tantalum scaffold similar to cancellous bone by depositing Ta on a carbon matrix using chemical vapor deposition (CVD), significantly improving its mechanical properties. Due to its good wetting properties and high surface energy, it can effectively enhance the adhesion, proliferation, and mineralization capabilities of osteoblasts. Simultaneously, the low elastic modulus and high coefficient of friction of porous tantalum materials effectively avoid stress shielding effects, minimizing marginal bone loss.

[0004] Although porous tantalum scaffolds have certain therapeutic effects in clinical practice, some researchers still believe that porous tantalum implants do not have sufficient osseointegration capacity, which affects the initial stability and long-term repair effect after implantation. Summary of the Invention

[0005] The purpose of this invention is to overcome the above-mentioned defects in the prior art and provide a medical nano-hydroxyapatite-coated porous tantalum implant material and its preparation method, which has mechanical properties similar to those of human bones and can be used as a permanent implant material for human bone defects, weight-bearing bones or non-weight-bearing parts. The invention utilizes chemical vapor deposition to uniformly deposit a tantalum coating on the surface of a graphite carbon skeleton, and then uses electrochemical deposition to prepare a nano-hydroxyapatite coating on the surface of the tantalum coating. The prepared medical nano-hydroxyapatite-coated porous tantalum implant material has a high porosity of >70% and an elastic modulus of <30 GPa.

[0006] To achieve the above objectives, the technical solution of the present invention is as follows:

[0007] A method for preparing a porous tantalum implant material with a nano-hydroxyapatite coating for medical use includes the following steps:

[0008] S1. The graphite carbon skeleton is etched with HCl solution, then washed and dried to obtain a porous carbon skeleton, which is then placed in the vapor deposition reaction chamber.

[0009] S2. A processing gas and a reducing gas are introduced into the vapor deposition reaction chamber to perform vapor deposition, thereby depositing a tantalum coating on the surface of the porous carbon framework to obtain a porous tantalum metal scaffold; the processing gas contains a tantalum source and a carrier gas;

[0010] S3. Dissolve the calcium source, phosphorus source and sodium chloride in deionized water to obtain a mixed solution;

[0011] S4. Adjust the pH of the mixture to 4.3 using a pH adjuster to obtain the electrolyte;

[0012] S5. Using the tantalum metal porous scaffold as the working electrode and graphite as the counter electrode, electrochemical deposition is performed in the electrolyte using a pulsed current mode to deposit a nano-hydroxyapatite coating on the surface of the tantalum metal porous scaffold. After washing and drying, the medical nano-hydroxyapatite coated porous tantalum implant material is obtained.

[0013] The present invention also discloses a medical nano-hydroxyapatite coated porous tantalum implant material prepared by the preparation method described above. The medical nano-hydroxyapatite coated porous tantalum implant material includes a porous carbon skeleton and a composite coating. The composite coating includes a tantalum coating vapor-deposited on the porous carbon skeleton and a nano-hydroxyapatite coating electrochemically deposited on the tantalum coating. The weight ratio of the tantalum coating in the composite coating is 70% to 80%.

[0014] Implementing the embodiments of the present invention will have the following beneficial effects:

[0015] (1) The medical nano-hydroxyapatite coated porous tantalum implant material of the present invention has high porosity and interconnected porosity, and the pores are uniform. It is a porous structure with interconnected pores and few dead cavities. It is similar to human cancellous bone and can promote bone ingrowth.

[0016] (2) The porous tantalum metal scaffold based on the tantalum coating of the present invention has good biocompatibility and obtains the best biomechanical properties according to the pore diameter of the tantalum coating and the porous carbon skeleton, reducing adverse effects such as stress shielding of adjacent bone after implantation.

[0017] (3) The preparation method of the present invention is simple and easy to operate. The porous carbon skeleton is easy to process into an irregular shape that is compatible with the implantation site before tantalum plating, avoiding the problems of porous tantalum material itself being difficult to process due to its physicochemical properties, causing great damage to the material during processing, and creating voids. At the same time, by controlling parameters such as the concentration of reactant gas, deposition temperature and reaction time during chemical vapor deposition, the tantalum metal coating is made uniform and dense, with a particle size of only 1μm to 5μm and a purity of over 99.5%, and has sufficient thickness, thereby enabling the material to obtain sufficient mechanical strength.

[0018] (4) In order to enhance the osseointegration capacity, the present invention modifies the surface of the tantalum coating by electrochemical deposition technology on the traditional porous tantalum material. By adjusting the composition ratio of the electrolyte and the deposition process parameters, a uniform and dense nano-hydroxyapatite coating is prepared on the tantalum coating. The surface modification of the implant enhances the bonding between the bone tissue and the implant, which can promote osteogenic and osseointegration, enhance the initial stability and long-term repair effect of the porous tantalum scaffold, and make up for the lack of osseointegration capacity of traditional porous tantalum metal implants.

[0019] (5) The medical nano-hydroxyapatite coated porous tantalum implant material of the present invention combines the advantages of porous carbon skeleton, tantalum metal and nano-hydroxyapatite. The composite coating not only has high bonding strength and good stability with the substrate, but also has good bioactivity, which is conducive to the rapid and stable bonding between the implant and bone tissue and subsequent long-term use. It can be applied to the repair of bone trauma and bone defects after osteonecrosis in multiple parts of the body. Attached Figure Description

[0020] Figure 1 This is a surface morphology diagram of the implant material in Embodiment 1 of the present invention.

[0021] Figure 2 This is a surface morphology diagram of the implant material of Comparative Example 1 of the present invention.

[0022] Figure 3 The images shown are SEM images of the implant materials of Embodiment 1 and Comparative Example 1 of the present invention.

[0023] Figure 4 This is a graph showing the EDX energy dispersive spectroscopy analysis results of Example 1 of the present invention.

[0024] Figure 5 These are micro-CT analysis images of different groups in week 8 of Example 1 and Comparative Example 1 of the present invention. Detailed Implementation

[0025] The present invention will be further described below with reference to specific embodiments, but this does not limit the present invention in any way.

[0026] In order to promote bone healing and maintain bone integration in a stable state over a long period of time, the inventors conducted in-depth research on the surface modification of porous Ta and found that coating metal implants with osteoconductive biomaterials can enhance bone integration capacity. Among them, hydroxyapatite (HA) is extremely similar to the inorganic components of hard tissues such as bone and teeth and has osteoconductive properties.

[0027] Therefore, the present invention obtained by the inventors based on these insights is as follows.

[0028] This invention discloses a method for preparing a porous tantalum implant material with a nano-hydroxyapatite coating, comprising the following steps:

[0029] S1. The graphite carbon skeleton is etched with HCl solution, then washed and dried to obtain a porous carbon skeleton, which is then placed in the vapor deposition reaction chamber.

[0030] Specifically, the medical nano-hydroxyapatite coated porous tantalum implant material of the present invention uses a high-temperature resistant graphite carbon framework as the base material to construct a three-dimensional porous scaffold similar to the microstructure of bone. This framework has a three-dimensional mesh structure with advantages such as high porosity and interconnected porosity, light weight, moderate strength, no cytotoxicity, and good biocompatibility. Furthermore, the graphite carbon framework can be fabricated using personalized 3D printing technology, making it more consistent with human anatomy and allowing for personalized customization based on the mechanical properties of the bone tissue at the implantation site.

[0031] In one specific embodiment, the concentration of the HCl solution is 10%; the etching time is 10 min to 20 min.

[0032] In one specific embodiment, the etched graphite carbon skeleton is cleaned sequentially with water and ethanol, and then dried with nitrogen.

[0033] S2. In the vapor deposition reaction chamber, a processing gas and a reducing gas are introduced to perform vapor deposition to deposit a tantalum coating on the surface of a porous carbon framework, thereby obtaining a porous tantalum metal scaffold; the processing gas includes a tantalum source and a carrier gas.

[0034] Specifically, the porous carbon skeleton obtained through step S1 is placed in a vapor deposition reaction chamber, and a treatment gas and a reducing gas are introduced to carry out a deposition reaction. When the treatment gas and the reducing gas are introduced, the tantalum metal compound in the treatment gas reacts with the reducing gas and is reduced to gaseous tantalum metal, which then penetrates and deposits onto the surface of the porous carbon skeleton and its pore surface to form a tantalum coating.

[0035] In one specific embodiment, a processing gas and a reducing gas are simultaneously introduced into the vapor deposition reaction chamber, and the reaction is carried out for 4 to 6 hours at a temperature of 900°C to 1500°C and a vacuum of 10 Pa to 15 Pa. The tantalum source is placed in the source tank and heated to 120°C to 250°C. The tantalum metal compound in the source tank is introduced into the reaction chamber using an inert gas at 300°C as the carrier gas.

[0036] In one specific embodiment, the flow rate of the processing gas is 80 ml / min to 100 ml / min; the flow rate of the reducing gas is 100 ml / min to 150 ml / min.

[0037] In one specific embodiment, the inert gas includes one or both of argon and helium.

[0038] In one specific embodiment, the tantalum source includes one or both of tantalum pentachloride and tantalum fluoride. Specifically, using vapor deposition technology, the tantalum metal compound is reduced into tantalum metal particles, which are then uniformly deposited on the surface of the porous carbon framework.

[0039] In one specific embodiment, the particle size of the tantalum source is 400 mesh.

[0040] In one specific embodiment, the reducing gas is hydrogen.

[0041] In one specific embodiment, step S2 further includes: after adjusting the size of the porous tantalum metal support to Φ10mm×1.5mm, ultrasonic cleaning is performed sequentially with acetone, anhydrous ethanol and deionized water for 20 minutes.

[0042] S3. Dissolve the calcium source, phosphorus source and sodium chloride in deionized water to obtain a mixed solution.

[0043] In one specific embodiment, deionized water is used to prepare a sodium chloride solution to enhance the conductivity of the solution. Then, a calcium source and a phosphorus source are added sequentially and placed on a magnetic stirrer until all the solutes are dissolved. The concentration of the calcium source in the mixture is 2.5 mmol / L, the concentration of the phosphorus source in the mixture is 1.5 mmol / L, and the concentration of sodium chloride in the mixture is 0.1 mol / L.

[0044] In one specific embodiment, the calcium source includes one or both of calcium nitrate and calcium phosphate; the phosphorus source includes one or both of sodium dihydrogen phosphate and ammonium dihydrogen phosphate.

[0045] S4. Adjust the pH of the mixture to 4.3 using a pH adjuster to obtain the electrolyte.

[0046] In one specific embodiment, in step S4, the pH adjuster is 10% hydrochloric acid.

[0047] S5. Using a porous tantalum metal scaffold as the working electrode and graphite as the counter electrode, electrochemical deposition is performed in an electrolyte using a pulsed current mode to deposit a nano-hydroxyapatite coating on the surface of the porous tantalum metal scaffold. After washing and drying, a medical nano-hydroxyapatite coated porous tantalum implant material is obtained.

[0048] In one specific embodiment, in the electrochemical device, a porous tantalum metal support is used as the working electrode, and two graphite electrodes are used as the counter electrodes. An electrochemical workstation is used, and electrochemical deposition is performed in the electrolyte using a pulsed current mode. The pulsed current is 0.075 mA to 0.085 mA, with a period of 17 s to 20.4 s. The cathode pulse conduction time is 16 s to 19.2 s, the anode pulse conduction time is 1 s to 1.2 s, and the electrochemical deposition time is 20 min to 30 min. A constant temperature water bath is used to maintain the electrolytic cell temperature at 85°C. After deposition, the cells are ultrasonically cleaned sequentially with anhydrous ethanol and deionized water for 10 min each, and then dried.

[0049] Specifically, this invention, through improvements in the preparation steps and further optimization of electrochemical deposition reaction parameters, determines specific electrolyte composition ratios and deposition process parameters, which facilitates the obtaining of nano-hydroxyapatite coatings with good morphology, uniform coating, and density. The surface modification of the implant enhances the bonding between bone tissue and the implant, promotes osteogenic and osseointegration, enhances the initial stability and long-term repair effect of porous tantalum scaffolds, and compensates for the shortcomings of traditional porous tantalum metal implants in osseointegration.

[0050] The present invention also discloses a medical nano-hydroxyapatite coated porous tantalum implant material prepared by the preparation method of any embodiment of the present invention. The medical nano-hydroxyapatite coated porous tantalum implant material includes a porous carbon skeleton and a composite coating; the composite coating includes a tantalum coating vapor-deposited on the porous carbon skeleton and a nano-hydroxyapatite coating electrochemically deposited on the tantalum coating; the weight ratio of the tantalum coating in the composite coating is 70% to 80%.

[0051] In one specific embodiment, the porous carbon framework has a porosity >70% and a pore size of 210μm to 600μm.

[0052] In one specific embodiment, the thickness of the tantalum coating is 40 μm to 60 μm.

[0053] In one specific embodiment, the thickness of the nano-hydroxyapatite coating is 3 μm to 5 μm.

[0054] In one specific embodiment, the porosity of the nano-hydroxyapatite coating is 75% to 85%, and the pore size is 400 μm to 600 μm.

[0055] In one specific embodiment, the medical nano-hydroxyapatite coated porous tantalum implant material has a porosity of 75% to 85%, an elastic modulus of <30 GPa, and a compressive strength of 30 MPa to 45 MPa, which is similar to the mechanical properties of human bone. It can be used as a permanent implant material in weight-bearing bones or non-weight-bearing parts of the human body, such as hip and knee joints, skull, intervertebral fusion devices, etc.

[0056] Specifically, the medical nano-hydroxyapatite coated porous tantalum implant material of the present invention combines the advantages of porous carbon skeleton, tantalum metal and nano-hydroxyapatite. The composite coating not only has high bonding strength and good stability with the substrate, but also has good bioactivity, which is conducive to the rapid and stable bonding between the implant and bone tissue and subsequent long-term use. It can be applied to the repair of bone trauma and bone defects after osteonecrosis in multiple parts of the body.

[0057] The following are specific embodiments.

[0058] Example 1

[0059] The preparation method of the medical nano-hydroxyapatite coated porous tantalum implant material in this embodiment includes the following steps:

[0060] S1. A graphite carbon skeleton with a porosity of 85% and a pore size of 600 μm is etched with a 10% HCl solution for 10 min, then washed with water and ethanol in sequence, and dried with nitrogen to obtain a porous carbon skeleton, which is then placed in a vapor deposition reaction chamber.

[0061] S2. Tantalum pentachloride powder with a particle size of 400 mesh is placed in a source tank and heated to 150°C. High-temperature argon gas (300°C) is introduced into the reaction chamber at a flow rate of 100 ml / min. The reaction chamber temperature is 1050°C and the vacuum degree of the reaction chamber is 10 Pa. While tantalum pentachloride powder is introduced into the reaction chamber with argon gas as the carrier gas, hydrogen gas is introduced at a flow rate of 120 ml / min. The reduction reaction is carried out for 4 hours, so that the tantalum metal reduced to metal powder is uniformly deposited on the surface of the graphite carbon skeleton and its pore surface to form a tantalum coating with a thickness of 50 μm, thus obtaining a porous tantalum metal scaffold.

[0062] S3. Prepare a sodium chloride solution using deionized water, then add calcium nitrate and sodium dihydrogen phosphate sequentially, and place on a magnetic stirrer until all the solutes are dissolved. The concentrations of calcium nitrate, sodium dihydrogen phosphate, and sodium chloride in the mixture are 2.5 mmol / L, 1.5 mmol / L, and 0.1 mol / L, respectively.

[0063] S4. Adjust the pH of the mixture to 4.3 using 10% hydrochloric acid to obtain the electrolyte.

[0064] S5. In the electrochemical apparatus, a porous tantalum metal scaffold was used as the working electrode, and two graphite electrodes were used as the counter electrodes. An electrochemical workstation was used, and electrochemical deposition was performed in the electrolyte using a pulsed current mode. The pulsed current was 0.075 mA with a period of 17 s. The cathode pulse conduction time was 16 s, the anode pulse conduction time was 1 s, and the electrochemical deposition time was 30 min. A constant temperature water bath was used to maintain the electrolytic cell temperature at 85°C. After deposition, a 4.5 μm thick nano-hydroxyapatite coating was formed. The coating was then ultrasonically cleaned sequentially with anhydrous ethanol and deionized water for 10 min each, and dried to obtain the medical nano-hydroxyapatite coated porous tantalum implant material of this embodiment.

[0065] The medical nano-hydroxyapatite coated porous tantalum implant material of this embodiment includes a porous carbon skeleton and a composite coating; the composite coating includes a tantalum coating vapor-deposited on the porous carbon skeleton and a nano-hydroxyapatite coating electrochemically deposited on the tantalum coating; the weight ratio of the tantalum coating in the composite coating is 75%. The porosity of the nano-hydroxyapatite coating is 80%, the pore size is 500 μm, the porosity of the medical nano-hydroxyapatite coated porous tantalum implant material is 80%, the elastic modulus is 10 GPa, and the maximum compressive strength is 35 MPa. The porosity is measured according to the national standard GB / T 21650.1-2008, and the elastic modulus is measured according to the method described in the national standard GB / T22315-2008.

[0066] Comparative Example 1

[0067] The only difference between this comparative example and Example 1 is that the porous tantalum implant material in this comparative example includes a porous carbon skeleton and a tantalum coating vapor-deposited on the porous carbon skeleton. The porous tantalum implant material has a porosity of 90%, an elastic modulus of 8 GPa, and a maximum compressive strength of 30 MPa.

[0068] Test case

[0069] Figure 1 and Figure 2 The images show the surface morphology of the implanted materials in Example 1 and Comparative Example 1 of this invention, respectively. It can be seen from the images that the surface morphology of the pores changed significantly before and after the nano-hydroxyapatite coating. After the nano-hydroxyapatite coating, the fine structure and morphological characteristics of the porous scaffold can be clearly observed, showing good three-dimensional connectivity.

[0070] Figure 3 The images show SEM images of the implanted materials in Example 1 and Comparative Example 1 of this invention. It can be seen that the morphology of the scaffold changed significantly after electrochemical deposition modification. Both coatings are continuous and dense, without obvious cracks or fractures, indicating that both coatings form a tight bond with the substrate.

[0071] Figure 4The image shows the EDX energy dispersive spectroscopy analysis results of Example 1 of the present invention. The main components include Ca, P, O and Ta.

[0072] Example 2

[0073] Following the method in Example 1, porous tantalum implant materials with nano-hydroxyapatite coating were prepared under different electrolyte composition ratios.

[0074] In this embodiment, the concentration of calcium nitrate in the mixture is 1.0 mmol / L, the concentration of sodium dihydrogen phosphate in the mixture is 1.5 mmol / L, and the concentration of sodium chloride in the mixture is 0.1 mol / L.

[0075] The nano-hydroxyapatite coating obtained in this embodiment has a porosity of 84% and a pore size of 520 μm. The porous tantalum implant material with nano-hydroxyapatite coating has a porosity of 84%, an elastic modulus of 10 GPa, and a maximum compressive strength of 25 MPa.

[0076] Based on the results of Example 1 and Example 2, it can be seen that when the calcium nitrate concentration is 1.5 mmol / L, the coating thickness becomes thinner, thereby increasing porosity and decreasing elastic modulus and compressive strength. When the calcium nitrate concentration is 2.5 mmol / L, the coating becomes thicker, reducing porosity, but conversely, the elastic modulus and compressive strength also decrease.

[0077] Example 3

[0078] Following the method in Example 1, porous tantalum implant materials with nano-hydroxyapatite coating were prepared under different electrochemical deposition times.

[0079] In this embodiment, the electrochemical deposition time is 60 min, and the porosity of the HA coating in the prepared medical nano-hydroxyapatite coated porous tantalum implant material is 75%, the pore size is 450 μm, the porosity of the medical nano-hydroxyapatite coated porous tantalum implant material is 75%, the elastic modulus is 12 GPa, and the maximum compressive strength is 40 MPa.

[0080] Based on the results of Example 1 and Example 3, it can be seen that the electrochemical deposition time affects the coating thickness, thereby affecting the porosity and compressive strength.

[0081] Example 4

[0082] Following the method in Example 1, porous tantalum implant materials with nano-hydroxyapatite coating were prepared at different electrochemical deposition temperatures of 60°C, 85°C, and 100°C.

[0083] Table 1. Performance of implant materials under different electrochemical deposition temperatures.

[0084]

[0085] As shown in Example 4, different electrochemical deposition temperatures affect the thickness of the HA coating, thus affecting its performance. Furthermore, temperatures above 85°C do not change the coating performance.

[0086] Example 5

[0087] Following the method in Example 1, medical nano-hydroxyapatite coated porous tantalum implant materials were prepared under different pulse currents of 0.025mA, 0.075mA, and 0.500mA.

[0088] Table 2 Performance of implant materials under different pulse current conditions

[0089]

[0090] According to the results of Example 5, different pulse currents affect the coating thickness within a certain limit; beyond that limit, no coating will form.

[0091] Example 6

[0092] New Zealand white rabbits (10 weeks old) were randomly divided into three groups: SiC, Ta, and Ha-Ta. Rabbits were anesthetized by intramuscular injection of 10% chloral hydrate (4 mg / kg). Subsequently, the fur on the right hind leg was shaved and disinfected with 70% ethanol. The skin and fascia were incised sequentially, the muscle was dissected, and after muscle dissection and exposure of the femoral condyle, a hole was drilled along the longitudinal axis of the femoral condyle using a round dental drill (2 mm in diameter). The pre-sterilized implant was then carefully inserted into place. The surgical site was then sealed in layers. Animals were sacrificed at week 8 to obtain their bone tissue. Figure 5 It can be seen that micro-CT shows that bone tissue grows well around the material, and the HA-coated group forms bone at a faster rate than the Ta-coated group.

[0093] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. A method for preparing a porous tantalum implant material with a medical nano-hydroxyapatite coating, characterized in that, Includes the following steps: S1. The graphite carbon skeleton is etched with HCl solution, then washed and dried to obtain a porous carbon skeleton, which is then placed in the vapor deposition reaction chamber. S2. A processing gas and a reducing gas are introduced into the vapor deposition reaction chamber to perform vapor deposition, thereby depositing a tantalum coating on the surface of the porous carbon framework to obtain a porous tantalum metal scaffold; the processing gas contains a tantalum source and a carrier gas; S3. Dissolve the calcium source, phosphorus source and sodium chloride in deionized water to obtain a mixed solution; S4. Adjust the pH of the mixture to 4.3 using a pH adjuster to obtain the electrolyte; S5. Using the porous tantalum metal scaffold as the working electrode and graphite as the counter electrode, electrochemical deposition is performed in the electrolyte using a pulsed current mode to deposit a nano-hydroxyapatite coating on the surface of the porous tantalum metal scaffold. After washing and drying, the medical nano-hydroxyapatite coated porous tantalum implant material is obtained. In step S3, the concentration of the calcium source in the mixture is 2.5 mmol / L, the concentration of the phosphorus source in the mixture is 1.5 mmol / L, and the concentration of the sodium chloride in the mixture is 0.1 mol / L. In step S5, during the electrochemical deposition, the pulse current is 0.075 mA, the period is 17 s, the cathode pulse conduction time is 16 s, the anode pulse conduction time is 1 s, the electrochemical deposition time is 30 min, and the electrochemical deposition temperature is 85 °C. The medical nano-hydroxyapatite coated porous tantalum implant material includes a porous carbon skeleton and a composite coating. The composite coating includes a tantalum coating vapor-deposited on the porous carbon skeleton and a nano-hydroxyapatite coating electrochemically deposited on the tantalum coating. The tantalum coating in the composite coating has a weight ratio of 70% to 80%; The thickness of the nano-hydroxyapatite coating is 4.5 μm; The porosity of the medical nano-hydroxyapatite coated porous tantalum implant material is 75%~85%, the elastic modulus is <30Gpa, and the compressive strength is 30MPa~45MPa; The porosity of the nano-hydroxyapatite coating is 75%~85%, and the pore size is 400μm~600μm.

2. The method for preparing the medical nano-hydroxyapatite coated porous tantalum implant material according to claim 1, characterized in that, In step S1, the concentration of the HCl solution is 10%; the etching time is 10 min to 20 min.

3. The method for preparing the medical nano-hydroxyapatite coated porous tantalum implant material according to claim 1, characterized in that, Step S2 specifically includes: simultaneously introducing a processing gas and a reducing gas into the vapor deposition reaction chamber, reacting for 4 to 6 hours at 900°C to 1500°C and a vacuum of 10 Pa to 15 Pa; placing the tantalum source into a source tank and heating it to 120°C to 250°C, then introducing the tantalum metal compound from the source tank into the reaction chamber using a 300°C inert gas as a carrier gas; the flow rate of the processing gas is 80 ml / min to 100 ml / min; the flow rate of the reducing gas is 100 ml / min to 150 ml / min; the inert gas includes one or both of argon and helium.

4. The method for preparing the medical nano-hydroxyapatite coated porous tantalum implant material according to claim 1, characterized in that, In step S2, the tantalum source includes one or both of tantalum pentachloride and tantalum fluoride; the particle size of the tantalum source is 400 mesh; and the reducing gas is hydrogen.

5. The method for preparing the medical nano-hydroxyapatite coated porous tantalum implant material according to claim 1, characterized in that, Step S2 also includes: after adjusting the size of the porous tantalum metal support to Φ10mm×1.5mm, ultrasonic cleaning is performed sequentially with acetone, anhydrous ethanol and deionized water for 20 minutes.

6. The method for preparing the medical nano-hydroxyapatite coated porous tantalum implant material according to claim 1, characterized in that, In step S3, the calcium source includes one or both of calcium nitrate and calcium phosphate; the phosphorus source includes one or both of sodium dihydrogen phosphate and ammonium dihydrogen phosphate. In step S4, the pH adjuster is 10% hydrochloric acid.

7. The method for preparing the medical nano-hydroxyapatite coated porous tantalum implant material according to claim 1, characterized in that, The porous carbon framework has a porosity of >70% and a pore size of 210μm~600μm; The thickness of the tantalum coating is 40μm~60μm.

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