Osteophilic intervertebral fusion cage and method of making same

Abstract

This application relates to the field of medical implants, specifically to an osteogenic intervertebral fusion device and its preparation method, comprising the following steps: Step 1: 3D printing tantalum metal powder to obtain a base layer; Step 2: 3D printing tantalum metal powder and osteogenic bioceramic onto the base layer to form a transition layer, obtaining a matrix; Step 3: Plasma-spraying osteogenic bioceramic onto the matrix to form a bioceramic layer, obtaining a preliminary product; Step 4: Immersing the preliminary product in a mixed solution of strontium phosphate and β-glycerophosphate magnesium phosphate, drying and curing to obtain the osteogenic intervertebral fusion device. In this application, the base layer can autonomously adjust its porosity, and the transition layer allows for a smooth stress transfer from rigid metal to flexible ceramic, reducing interfacial stress concentration. The bioceramic layer and the transition layer form an interlocking structure, enhancing the interfacial shear strength. Strontium phosphate and β-glycerophosphate magnesium phosphate are enriched on the material surface, which can both rapidly induce osteoblast migration and continuously promote mineralization.

Description

Technical Field

[0001] This application relates to the field of medical implants, specifically to a bone-bonded interbody fusion device and its preparation method. Background Technology

[0002] Lumbar disc herniation and cervical spondylosis, among other degenerative disc diseases, are common and prevalent in modern society, severely impacting patients' quality of life. Spinal fusion is one of the most common techniques in spinal surgery. It primarily aims to establish immediate spinal stability, then utilize the bone formation, bone induction, and bone conduction effects of implants to promote bony fusion of the spine, achieving long-term stability.

[0003] Currently, interbody fusion has become the primary treatment for conditions such as lumbar instability, lumbar spinal stenosis, degenerative spondylolisthesis, degenerative scoliosis, pseudoarthrosis, and degenerative disc disease. Titanium-based interbody fusion devices are widely used clinically, but their limitations include limited bone ingrowth and a risk of instability after prolonged implantation. Tantalum, due to its good biocompatibility, suitable biomechanical properties, and excellent bioactivity, has become the most promising alternative to titanium-based interbody fusion devices.

[0004] Tantalum-based interbody fusion cages are mostly fabricated using 3D printing. However, due to the two main components of tantalum-based interbody fusion cages, tantalum metal and bioceramic, microcracks are easily formed at the metal-ceramic interface during 3D printing, which reduces fatigue strength (especially when subjected to cyclic loads on the spine), thus limiting the application of tantalum-based interbody fusion cages. Summary of the Invention

[0005] To address the issue of microcracks forming at the metal-ceramic interface during conventional 3D printing of tantalum-based metal interbody fusion devices, which reduces fatigue strength, this application provides a bone-friendly interbody fusion device and its preparation method.

[0006] In a first aspect, this application provides a method for preparing a bone-bonded interbody fusion device, employing the following technical solution:

[0007] A method for preparing an osteophyte interbody fusion device includes the following steps:

[0008] Step 1: Obtain the base layer by 3D printing tantalum metal powder;

[0009] Step 2: Tantalum metal powder and osteogenic bioceramics are 3D printed onto the substrate layer to form a transition layer, thus obtaining the matrix;

[0010] Step 3: Plasma spraying of osteogenic bioceramics onto the substrate to form a bioceramic layer, obtaining the initial product;

[0011] Step 4: Immerse the initial product in a mixed solution of strontium phosphate and β-glycerol magnesium phosphate, dry and solidify to obtain an osteogenic intervertebral fusion device.

[0012] By adopting the above technical solution, this application first uses tantalum metal powder as the base layer. The adjustable porosity range of the 3D printed base layer is higher than that of 3D printing after mixing raw materials. The high porosity region promotes bone ingrowth to form "bio-rivets," significantly improving fatigue resistance. The transition layer is formed by mixing tantalum metal powder and osteogenic bioceramics, which allows stress to be smoothly transferred from rigid metal to flexible ceramics, reducing interface stress concentration. The micron-scale ceramic layer formed by plasma spraying forms an interlocking structure with the transition layer, deflecting the crack propagation path. During plasma spraying, molten ceramic droplets impact the tantalum matrix, forming micro-region metallurgical bonding zones and diffusion layers, enhancing the interface shear strength, which is higher than the mechanical bonding of mixed printing. The impregnation process enriches strontium phosphate and β-glycerophosphate magnesium phosphate on and near the material surface, achieving early burst release and rapidly inducing osteoblast migration; long-term slow release continuously promotes mineralization.

[0013] This application divides the osteogenic intervertebral fusion device into a basal layer, a transition layer, and a bioceramic layer. The basal layer can autonomously adjust its porosity, while the transition layer facilitates a smooth stress transfer from rigid metal to flexible ceramic, reducing interfacial stress concentration. The bioceramic layer and the transition layer form an interlocking structure, deflecting crack propagation paths and enhancing interfacial shear strength, exceeding that of mechanical bonding achieved through hybrid printing. The impregnation process enriches strontium phosphate and β-glycerophosphate magnesium phosphate on and near the material surface, rapidly inducing osteoblast migration and continuously promoting mineralization.

[0014] Preferably, in step 2, the mass ratio of tantalum metal powder to osteogenic bioceramic in the transition layer is 1:1.

[0015] By employing the above technical solution, the tantalum metal powder and osteogenic bioceramic, when mixed in a 1:1 ratio, exhibit an elastic modulus between that of cortical and cancellous bone, effectively reducing the stress shielding effect. Furthermore, the ductility of the tantalum metal and the rigidity of the ceramic complement each other after mixing; the tantalum phase absorbs crack propagation energy, while the ceramic phase inhibits cracking through a pinning effect. After mixing, the tantalum metal phase induces alkaline phosphatase expression in osteoblasts, while the ceramic phase provides a mineralization microenvironment.

[0016] Preferably, the transition layer is divided into a near-base layer, an intermediate layer, and a near-surface layer in sequence.

[0017] Preferably, the mass ratio of tantalum metal powder to osteogenic bioceramic in the near-basal layer is 7:3;

[0018] The mass ratio of tantalum metal powder to osteogenic bioceramic in the intermediate layer is 5:5.

[0019] The mass ratio of tantalum metal powder to osteogenic bioceramic in the near-surface layer is 3:7.

[0020] By employing the above technical solution, the transition layer is printed in a gradient manner, gradually dividing into a near-base layer, an intermediate layer, and a near-surface layer. The elastic modulus decreases stepwise from the base layer to the ceramic layer, avoiding abrupt changes in mechanical properties. The gradient design reduces the thermal expansion coefficient of adjacent layers, and the residual stress during the cooling process also decreases accordingly. The gradient interface forms an energy dissipation barrier, requiring crack propagation to cross three different fracture toughness zones, significantly reducing the fatigue crack propagation rate. Each layer interface forms a diffusion reaction zone, further enhancing the gradient interlocking effect.

[0021] Preferably, the tantalum metal powder is pretreated, including the following steps:

[0022] Tantalum metal powder is soaked in NaOH solution and then heat-treated to obtain pretreated tantalum metal powder.

[0023] By employing the above technical solution, tantalum metal powder is first dissolved in NaOH solution to remove the loose surface layer of tantalum oxide, exposing the fresh metal surface and simultaneously generating a sodium tantalate transition layer. Then, heat treatment decomposes the sodium tantalate transition layer, reconstructing a dense nanocrystalline tantalum oxide layer. This dense nanocrystalline tantalum oxide layer reacts with osteogenic bioceramics to generate a calcium tantalite-phosphorus transition phase, achieving a metallurgical-chemical dual integration. The nanocrystalline tantalum oxide layer, acting as a reinforcing shell, inhibits dislocation aggregation at tantalum grain boundaries, improving fatigue resistance. The change in surface zeta potential after pretreatment preferentially adsorbs phosphate ions, accelerating the deposition of bone-like apatite.

[0024] Preferably, the pretreated tantalum metal powder is spheroidized by radio frequency plasma and then coated with stearic acid ethanol solution to obtain spheroidized tantalum metal powder.

[0025] By employing the above technical solution, the pre-treated tantalum metal powder, after etching, has a rough and angular surface, which is not conducive to spraying. Radio frequency plasma causes the tantalum powder surface to melt instantaneously, shrinking into perfect spheres under the action of surface tension. During the spheroidization process, the internal pores are filled with liquid tantalum at high temperature, and rapid cooling forms ultrafine equiaxed crystals, resulting in grain refinement and improved fatigue resistance. Further coating with a stearic acid-ethanol solution prevents powder agglomeration, and the coating layer reduces the powder / carrier gas friction coefficient, optimizing the flow field.

[0026] Preferably, a nitrogen-hydrogen mixture is introduced during heat treatment, with an oxygen partial pressure ≤10. -3 Pa.

[0027] By adopting the above technical solution, the oxygen partial pressure is ≤10. -3Pa keeps the system in the thermodynamically stable region of tantalum, allowing for deep deoxygenation of hydrogen. Nitrogen reduces the risk of hydrogen explosion and stabilizes the gas flow. Nitrogen can also nitrid the surface of tantalum metal powder, forming a nitrogen-doped tantalum oxide structure. Oxygen partial pressure ≤10. -3 Pa suppresses grain boundary diffusion, making the ratio of grain growth rate (G) to nucleation rate (N) G / N < 1, thus achieving ultra-high density nucleation.

[0028] Preferably, the osteogenic bioceramic is pretreated, including the following steps:

[0029] The osteogenic bioceramic is subjected to plasma blasting followed by acid etching, then a Ti layer is deposited, and finally a tantalum layer is deposited using magnetron sputtering.

[0030] By employing the above technical solutions, high-speed plasma impact forms inverted conical pits, achieving mechanical interlocking and constructing a multi-level micro / nano structure. Acid etching dissolves the grain boundary phase of osteogenic bioceramics, forming honeycomb-like nanopores. The deposition of a Ti layer facilitates the transition of thermal expansion coefficients, hindering crack propagation at the tantalum metal powder / osteogenic bioceramic interface. The tantalum plating layer acts as a flexible buffer layer, alleviating the stress shielding effect between the ceramic and bone tissue.

[0031] Preferably, the osteogenic bioceramic powder is spheroidized using fluidized bed technology, followed by plasma blasting and acid etching, then a Ti layer is deposited, and finally a tantalum layer is deposited using magnetron sputtering.

[0032] By adopting the above technical solution, the high-pressure airflow causes the powder to rotate and melt at high speed in the fluidization chamber, and the surface tension drives the formation of perfect spheres, which makes subsequent pretreatment operations more convenient.

[0033] Secondly, this application provides a bone-bonded interbody fusion device, which adopts the following technical solution:

[0034] A bone-bonded interbody fusion device is prepared by the above-mentioned method for preparing a bone-bonded interbody fusion device.

[0035] In summary, this application has the following beneficial effects:

[0036] 1. Because this application divides the osteogenic intervertebral fusion device into a base layer, a transition layer, and a bioceramic layer, the base layer can autonomously adjust its porosity, the transition layer allows stress to be smoothly transferred from rigid metal to flexible ceramic, reducing interfacial stress concentration; the bioceramic layer and the transition layer form an interlocking structure, which deflects the crack propagation path and enhances the interfacial shear strength, which is higher than the mechanical bonding of hybrid printing; the impregnation process enriches strontium phosphate and β-glycerophosphate magnesium phosphate on and near the surface of the material, which can both rapidly induce osteoblast migration and continuously promote mineralization;

[0037] 2. In this application, the transition layer is printed according to a gradient, gradually dividing into a near-base layer, an intermediate layer, and a near-surface layer. The gradient interface forms an energy dissipation barrier, requiring crack propagation to cross three different fracture toughness zones, thus significantly reducing the fatigue crack propagation rate. Each layer interface forms a diffusion reaction zone, further enhancing the gradient interlocking effect.

[0038] 3. This application pre-treats tantalum metal powder, which can generate a phosphorus tantalum calcium stone transition phase through a nanocrystalline tantalum oxide layer, achieving a metallurgical-chemical dual combination; and the nanocrystalline tantalum oxide layer, as a reinforcing shell, can suppress the accumulation of dislocations at tantalum grain boundaries and improve fatigue strength. Detailed Implementation

[0039] The raw materials in this application include the following:

[0040] Tantalum metal powder: Medical grade spherical high-purity tantalum metal powder, purity ≥99.99wt%, 15-45μm;

[0041] Osteopathic bioceramics: Commercially available products using β-TCP bioceramics;

[0042] Magnesium β-glycerophosphate: Using commercially available product 927-20-8;

[0043] Stearic acid: Uses a commercially available medical-grade product with CAS number 57-11-4;

[0044] The present application will be further described in detail below with reference to embodiments and comparative examples.

[0045] Example 1

[0046] A method for preparing an osteophyte interbody fusion device includes the following steps:

[0047] Step 1: 3D print tantalum metal powder to obtain a base layer with a thickness of 2mm;

[0048] Step 2: Tantalum metal powder and osteogenic bioceramic are 3D printed on the substrate layer in a mass ratio of 5:5 to form a transition layer with a thickness of 0.6 mm, thus obtaining the matrix.

[0049] Step 3: Plasma spraying of osteogenic bioceramic onto the substrate at a power of 40 kW and a spraying distance of 100 mm forms a bioceramic layer with a thickness of 0.1 mm, yielding the initial product.

[0050] Step 4: The initial product was immersed in a mixed solution of strontium phosphate and β-glyceromagnesium phosphate (strontium phosphate concentration 1.0 mol / L, β-glyceromagnesium phosphate concentration 0.5 mol / L) for 24 h, vacuum dried at 40 °C for 4 h, heat treated at 60 °C for 2 h, and cured under nitrogen protection at 120 °C for 2 h to obtain the osteogenic intervertebral fusion device.

[0051] The above 3D printing process parameters are as follows: laser power is 180W, exposure time is 30μs, spot spacing is 30μm, line spacing is 30μm, and powder thickness is 30μm. The substrate temperature during printing is 170℃.

[0052] Examples 2-4

[0053] In Examples 2-3, based on the preparation method of Example 1, the mass ratio of tantalum metal powder and osteogenic bioceramic was adjusted in step 2. The specific adjustments are shown in Table 1.

[0054] Example 4 is based on the preparation method of Example 1, but step 2 is adjusted as follows:

[0055] Tantalum metal powder and osteogenic bioceramic were 3D printed on the substrate layer with a mass ratio of 7:3 to form a near-substrate layer with a thickness of 0.2 mm.

[0056] 3D printing was performed on the near-basal layer, with tantalum metal powder and osteogenic bioceramic in a mass ratio of 5:5 to form an intermediate layer of 0.2 mm.

[0057] 3D printing was performed on the intermediate layer, with a mass ratio of tantalum metal powder and osteogenic bioceramic of 3:7, forming a near-surface layer of 0.2 mm.

[0058] A transition layer consisting of a near-base layer, an intermediate layer, and a near-surface layer, with a thickness of 0.6 mm, is formed to obtain the matrix.

[0059] Comparative Example 1

[0060] A method for preparing an osteophyte interbody fusion device includes the following steps:

[0061] 30wt% osteogenic bioceramic, 1.5wt% strontium phosphate and 1.0wt% β-glycerophosphate magnesium phosphate were mixed in 67.5wt% tantalum metal powder to obtain a mixed raw material; the mixed raw material was then 3D printed to obtain an osteogenic intervertebral fusion device.

[0062] Performance testing

[0063] The osteophyte interbody fusion devices of Examples 1-4 and Comparative Example 1 were subjected to the following performance tests, and the test results are shown in Table 1.

[0064] Bond strength retention rate

[0065] The fatigue resistance of the osteophyte interbody fusion device was determined according to ISO 12189:2008.

[0066] Biocompatibility

[0067] The biocompatibility, i.e., cell viability, of the osteosynthetic interbody fusion device was measured according to ISO 10993:2018.

[0068] Table 1. Mass ratio and performance test results of tantalum metal powder and osteogenic bioceramics in the transition layer of Examples 1-4 and Comparative Example 1.

[0069]

[0070] Referring to Table 1, comparing Examples 1-4 and Comparative Example 1, it is evident that printing the osteogenic intervertebral fusion device in three layers—a basal layer, a transition layer, and a bioceramic layer—is more effective than mixing various materials for 3D printing. This is because the basal layer can autonomously adjust its porosity, the transition layer allows for a smooth stress transfer from rigid metal to flexible ceramic, reducing interfacial stress concentration, and the bioceramic layer forms an interlocking structure with the transition layer, deflecting crack propagation paths and enhancing interfacial shear strength, which is superior to the mechanical bonding achieved through mixed printing. The impregnation process enriches strontium phosphate and β-glycerophosphate magnesium phosphate on and near the material surface, rapidly inducing osteoblast migration and continuously promoting mineralization.

[0071] Among these methods, a 1:1 mass ratio of tantalum metal powder to osteogenic bioceramic in the transition layer yields better results. This is because a 1:1 mixture of tantalum metal powder and osteogenic bioceramic results in an elastic modulus between that of cortical and cancellous bone, effectively reducing the stress shielding effect. Furthermore, the ductility of tantalum metal and the rigidity of the ceramic complement each other after mixing; the tantalum phase absorbs crack propagation energy, while the ceramic phase inhibits cracking through a pinning effect. After mixing, the tantalum metal phase induces alkaline phosphatase expression in osteoblasts, while the ceramic phase provides a mineralization microenvironment.

[0072] Printing the transition layer in a gradient pattern—near the substrate, intermediate layer, and near the surface—further enhances the effect. This is because printing the transition layer in a gradient, gradually dividing it into near-substrate, intermediate, and near-surface layers, allows the elastic modulus to decrease stepwise from the substrate layer to the ceramic layer, avoiding abrupt changes in mechanical properties. The gradient design reduces the thermal expansion coefficient of adjacent layers, thus lowering residual stress during cooling. The gradient interface forms an energy dissipation barrier, requiring crack propagation to cross three different fracture toughness zones, significantly reducing the fatigue crack propagation rate. Each layer interface forms a diffusion reaction zone, further strengthening the gradient interlocking effect.

[0073] Examples 5-7

[0074] Example 5, based on the preparation method of Example 1, involves pretreating tantalum metal powder, including the following steps:

[0075] Tantalum metal powder was soaked in NaOH solution (NaOH concentration 5 mol / L) for 24 h, and then heat-treated at 600℃ for 1 h to obtain pretreated tantalum metal powder.

[0076] Example 6, based on the preparation method of Example 1, involves pretreating tantalum metal powder, including the following steps:

[0077] Tantalum metal powder was soaked in NaOH solution (NaOH concentration 5 mol / L) for 24 h, and then heat-treated at 600℃ for 1 h to obtain pretreated tantalum metal powder.

[0078] The pretreated tantalum metal powder was spheroidized by radio frequency plasma at a power of 50 kW and a carrier gas flow rate of 20 L / min, and then coated with a stearic acid ethanol solution (stearic acid concentration of 0.5 wt%) to obtain spheroidized tantalum metal powder.

[0079] Example 7, based on the preparation method of Example 1, involves pretreating tantalum metal powder, including the following steps:

[0080] Tantalum metal powder was soaked in NaOH solution (5 mol / L) for 24 h, and then heat-treated at 600 °C for 1 h. During the heat treatment, a nitrogen-hydrogen mixture (volume ratio 95:5) was introduced, with an oxygen partial pressure ≤10. -3 Pa, to obtain pretreated tantalum metal powder.

[0081] The bone-bonded interbody fusion devices of Examples 5-7 were subjected to the above performance tests, and the test results are shown in Table 2.

[0082] Table 2 Performance test results for Examples 1 and 5-7

[0083]

[0084] Referring to Table 2, a comparison of Examples 1 and 5-7 shows that pretreatment of tantalum metal powder yields better results. This is because: firstly, the loose surface layer of tantalum oxide in the tantalum metal powder is dissolved in NaOH solution, exposing the fresh metal surface and simultaneously generating a sodium tantalate transition layer. Then, heat treatment decomposes the sodium tantalate transition layer, reconstructing a dense nanocrystalline tantalum oxide layer. This dense nanocrystalline tantalum oxide layer reacts with osteogenic bioceramics to generate a calcium tantalite transition phase, achieving a metallurgical-chemical dual integration. The nanocrystalline tantalum oxide layer, acting as a reinforcing shell, can inhibit dislocation aggregation at tantalum grain boundaries, improving fatigue resistance. The change in surface zeta potential after pretreatment preferentially adsorbs phosphate ions, accelerating the deposition of bone-like apatite.

[0085] Further processing of the pretreated tantalum metal powder yields even better results. This is because the surface of the pretreated tantalum metal powder is rough and angular after etching, which is unfavorable for spraying. Radio frequency plasma causes the tantalum powder surface to melt instantaneously, shrinking into perfect spheres under surface tension. During the spheroidization process, the internal pores are filled with liquid tantalum at high temperature, and rapid cooling forms ultrafine equiaxed crystals, resulting in grain refinement and improved fatigue resistance. Coating with a stearic acid-ethanol solution further prevents powder agglomeration, reduces the powder / carrier gas friction coefficient, and optimizes the flow field.

[0086] Optimizing the heat treatment process during the pretreatment of tantalum metal powder can further enhance the effect. This is because the oxygen partial pressure is ≤10. -3 Pa keeps the system in the thermodynamically stable region of tantalum, allowing for deep deoxygenation of hydrogen. Nitrogen reduces the risk of hydrogen explosion and stabilizes the gas flow. Nitrogen can also nitrid the surface of tantalum metal powder, forming a nitrogen-doped tantalum oxide structure. Oxygen partial pressure ≤10. -3 Pa suppresses grain boundary diffusion, making the ratio of grain growth rate (G) to nucleation rate (N) G / N < 1, thus achieving ultra-high density nucleation.

[0087] Examples 8-9

[0088] Example 8, based on the preparation method of Example 1, involves pretreating the osteogenic bioceramic, including the following steps:

[0089] The osteogenic bioceramic was subjected to plasma blasting (alumina particles, 0.3 MPa pressure), followed by acid etching in 10% HF solution for 30 s, then deposition of a 50 nm Ti layer, and finally magnetron sputtering to deposit a 100 nm thick tantalum layer.

[0090] Example 9, based on the preparation method of Example 1, involves pretreating the osteogenic bioceramic, including the following steps:

[0091] The osteogenic bioceramic powder was spheroidized using fluidized bed technology (temperature 1200℃, time 2h), followed by plasma blasting (alumina particles, pressure 0.3MPa), acid etching in 10% HF solution for 30s, deposition of a 50nm Ti layer, and then magnetron sputtering to deposit a 100nm tantalum layer.

[0092] The bone-bonded interbody fusion devices of Examples 8-9 were subjected to the above performance tests, and the test results are shown in Table 3.

[0093] Table 3 Performance test results for Examples 1 and 8-9

[0094]

[0095] Referring to Table 3, a comparison of Examples 1 and 8-9 shows that pretreatment of the osteogenic bioceramic yields better results. This is because: high-speed plasma impact forms inverted conical pits, achieving mechanical interlocking and constructing a multi-level micro / nano structure. Acid etching dissolves the grain boundary phase of the osteogenic bioceramic, forming honeycomb-like nanopores. The deposition of a Ti layer facilitates the transition of thermal expansion coefficients, hindering crack propagation at the tantalum metal powder / osteogenic bioceramic interface. The tantalum plating layer acts as a flexible buffer layer, alleviating the stress shielding effect between the ceramic and bone tissue.

[0096] Pre-treatment with spheroidization yields better results. This is because the high-pressure airflow causes the powder to rotate and melt at high speed in the fluidization chamber, and the surface tension drives the formation of perfect spheres, which facilitates subsequent pre-treatment operations.

[0097] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A method of making a bone-seeking intervertebral fusion cage, comprising: The method comprises the following steps: Step 1: obtaining a base layer by 3D printing of pretreated tantalum metal powder; Step 2: forming a transition layer by 3D printing of pretreated tantalum metal powder and osteoactive bioceramics on the base layer to obtain a base body; Step 3: forming a bioceramic layer by plasma spraying of osteoactive bioceramics on the base body to obtain a preliminary product; Step 4: immersing the preliminary product in a mixed solution of strontium phosphate and beta-glycerophosphate magnesium, and drying and solidifying to obtain an osteophilic intervertebral fusion cage. The method for preparing the pretreated tantalum metal powder comprises the following steps: Soaking tantalum metal powder in a NaOH solution to form a sodium tantalate transition layer, and then performing heat treatment to reconstitute a dense nanocrystalline tantalum oxide layer to obtain pretreated tantalum metal powder.

2. The method of claim 1, wherein: In step 2, the mass ratio of tantalum metal powder to osteoactive bioceramics in the transition layer is 1:

1.

3. The method of claim 2, wherein: The transition layer is sequentially divided into a near-base layer, an intermediate layer, and a near-surface layer.

4. The method for preparing the osteophilic intervertebral fusion cage according to claim 3, characterized in that: The mass ratio of tantalum metal powder to osteoactive bioceramics in the near-base layer is 7:3; The mass ratio of tantalum metal powder to osteoactive bioceramics in the intermediate layer is 5:5; The mass ratio of tantalum metal powder to osteoactive bioceramics in the near-surface layer is 3:

7.

5. The method of claim 1, wherein: The pretreated tantalum metal powder is subjected to radio frequency plasma spheroidization, and then coated with a stearic acid ethanol solution to obtain spheroidized tantalum metal powder.

6. The method of claim 1, wherein: The nitrogen-hydrogen mixed gas is introduced during the heat treatment, and the oxygen partial pressure is ≤10 Pa. -3 Pa.

7. The method for preparing the osteophilic intervertebral fusion cage according to claim 1, characterized in that: The osteoactive bioceramics are pretreated by the following steps: After plasma sandblasting and acid etching of the osteoactive bioceramics, a Ti layer is deposited, and then a tantalum layer is deposited by magnetron sputtering.

8. The method for preparing the osteophilic intervertebral fusion cage according to claim 7, characterized in that: The osteoactive bioceramics are pretreated by the following steps:

9. A bone-seeking intervertebral fusion cage, characterized by: The osteoactive bioceramics are pretreated by the following steps: The osteophilic intervertebral fusion cage is prepared by the method for preparing the osteophilic intervertebral fusion cage according to any one of claims 1-8.

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