A bone implant material, its preparation method and use

Abstract

This invention provides a bone implant material, its preparation method, and its application, relating to the field of biomedical materials technology. The preparation method of the bone implant material includes: preparing a ceramic slurry using silicon nitride ceramic powder, a dispersant, a sintering aid, a defoamer, a binder, and a solvent as raw materials; freeze-casting the ceramic slurry to obtain a first ceramic preform; freeze-drying the first ceramic preform to obtain a second ceramic preform; sequentially subjecting the second ceramic preform to sintering, surface oxidation, sol-gel modification, and heat treatment to obtain a modified ceramic preform; and placing the modified ceramic preform in a molten metal for pressure infiltration and cooling to room temperature to obtain the bone implant material. The bone implant material prepared by this invention exhibits superior corrosion resistance, rapid bone tissue regeneration capacity, excellent biocompatibility, an elastic modulus matching bone tissue, and long-term implantation stability.

Description

Technical Field

[0001] This invention relates to the field of biomedical materials technology, and more specifically, to a bone implant material, its preparation method, and its application. Background Technology

[0002] With the rising incidence of orthopedic diseases, the demand for bone implant materials is increasing. Ideal bone implant materials should possess rapid bone tissue regeneration capabilities, good biocompatibility, an elastic modulus matching bone tissue, and long-term implant stability. However, existing bone repair materials have many shortcomings: metal bone repair materials are prone to stress shielding effects and corrosion problems; ceramic bone repair materials, while exhibiting good biocompatibility, generally lack osteoinductive activity and have a high elastic modulus; polymer materials often face problems of insufficient strength and difficulty in precisely controlling degradation rates. Therefore, how to obtain bone implant materials with superior corrosion resistance, rapid bone tissue regeneration capabilities, good biocompatibility, an elastic modulus matching bone tissue, and long-term implant stability has become an urgent technical problem to be solved. Summary of the Invention

[0003] The problem addressed by this invention is: how to obtain bone implant materials with better corrosion resistance, rapid bone tissue regeneration capacity, better biocompatibility, elastic modulus matching bone tissue, and long-term implantation stability.

[0004] To address the above problems, the present invention provides a method for preparing a bone implant material, comprising: Step S1: Prepare ceramic slurry using silicon nitride ceramic powder, dispersant, sintering aid, defoamer, binder and solvent as raw materials; Step S2: The ceramic slurry is freeze-cast to obtain the first ceramic blank; Step S3: Under vacuum conditions, the first ceramic preform is freeze-dried to obtain the second ceramic preform; Step S4: Under a protective gas atmosphere, the second ceramic preform is sintered to obtain the first ceramic preform. Step S5: Perform surface oxidation treatment on the first ceramic preform to obtain the second ceramic preform; wherein, the surface oxidation treatment temperature is 600℃ to 1100℃; Step S6: Modify the second ceramic preform with sol-gel to obtain the third ceramic preform; Step S7: The third ceramic preform is subjected to heat treatment to obtain a modified ceramic preform; wherein the heat treatment temperature is 500℃ to 1000℃. Step S8: Place the modified ceramic preform in a molten metal for pressure infiltration, and cool to room temperature to obtain the bone implant material.

[0005] Optionally, in step S1, the mass ratio of the silicon nitride ceramic powder, the dispersant, the sintering aid, the defoamer, the binder and the solvent is (10 to 70): (0.5 to 5): (0.5 to 5): (0.5 to 5): (40 to 70).

[0006] Optionally, in step S1, the dispersant includes at least one of tetramethylammonium hydroxide, ammonium polyacrylate, sodium polyacrylate, sodium hexametaphosphate, and BYK163; the sintering aid includes at least one of rare earth oxides, alumina, and silica; the defoamer includes at least one of n-butanol, sec-butanol, and isobutanol; the binder includes at least one of polyvinyl alcohol, carboxymethyl cellulose, sodium alginate, polymethyl methacrylate, polyvinyl butyral, and agarose; and the solvent includes at least one of water and tert-butanol.

[0007] Optionally, the temperature for freeze casting is between -10°C and -197°C; and the temperature for freeze drying is between -20°C and -50°C.

[0008] Optionally, in step S4, the protective gas atmosphere is selected from one of nitrogen atmosphere, argon atmosphere, helium atmosphere, neon atmosphere, krypton atmosphere, xenon atmosphere and radon atmosphere; the sintering treatment temperature is 1500℃ to 2000℃ and the time is 1h to 4h.

[0009] Optionally, in step S6, the sol-gel modification of the second ceramic preform includes: vacuum impregnating the second ceramic preform in a sol, followed by gelation treatment, and finally drying treatment; wherein the sol includes at least one of nano-silica, mesoporous bioglass sol, zinc oxide sol, strontium oxide sol, hydroxyapatite sol, and phosphate sol.

[0010] Optionally, in step S8, the material of the molten metal is selected from at least one of magnesium, magnesium alloy, iron, iron alloy, zinc, and zinc alloy.

[0011] Optionally, in step S8, the pressure of the pressure impregnation is 0.5 MPa to 10 MPa, and the time is 5 min to 60 min.

[0012] The present invention also provides a bone implant material, which is prepared by the bone implant material preparation method described above.

[0013] Application of a bone implant material as described above in the preparation of bone implant patches, bone implant rods and complex bone implant components.

[0014] Compared with related technologies, this invention constructs a silicon nitride ceramic preform with high connectivity and directional pore structure through freeze casting and vacuum freeze drying. A high-strength, low-defect ceramic framework is obtained by sintering under a protective atmosphere. Subsequently, surface oxidation treatment at 600℃ to 1100℃ generates a dense and stable silica transition layer on the silicon nitride surface in situ. This transition layer not only effectively blocks the erosion of the ceramic matrix by body fluids, thus significantly improving the material's corrosion resistance, but also provides a highly active hydroxyl surface for subsequent sol-gel coating, enhancing coating adhesion and uniformity. Based on this, a bioactive sol is deposited using the sol-gel method, and the coating is densified and crystallized through heat treatment at 500℃ to 1000℃, forming a composite material with... The nanoscale bioactive interface, possessing osteoinductive, ion-release, and antibacterial properties, significantly accelerates bone tissue regeneration and ensures excellent biocompatibility. Finally, the molten metal is introduced into the ceramic pores via pressure infiltration, forming a metal-ceramic composite bone implant material. After implantation, the slow influx of degradable metal ions from the implant material promotes bone healing. Once mature bone tissue is formed, the elastic modulus of the implant material matches that of the bone tissue, preventing stress shielding. The oxide layer and dense coating together construct multiple barriers, inhibiting metal corrosion and interfacial delamination, thereby achieving synergistic optimization of corrosion resistance, bone regeneration capacity, biocompatibility, mechanical fit, and long-term implantation stability. In summary, the bone implant material prepared by the method of this invention exhibits superior corrosion resistance, rapid bone tissue regeneration capacity, excellent biocompatibility, an elastic modulus matching that of bone tissue, and long-term implantation stability. This bone implant material can be used to prepare bone implant patches, bone implant rods, and complex bone components, achieving an integrated application of "structural adaptation, functional induction, and long-term stability," significantly improving the success rate of clinical implantation and reducing the risk of secondary surgery. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the preparation method of bone implant material in an embodiment of the present invention. Detailed Implementation

[0016] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Although some embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the present invention. It should be understood that the accompanying drawings and embodiments of the present invention are for illustrative purposes only and are not intended to limit the scope of protection of the present invention.

[0017] Unless otherwise defined, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0018] The term "comprising" and its variations as used herein are open-ended, meaning "including but not limited to"; the term "based on" means "at least partially based on"; the term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments"; and the term "optionally" means "optional embodiments". Definitions of other terms will be given in the following description. It should be noted that the concepts of "first," "second," etc., mentioned in this invention are used to distinguish different objects, not to describe a specific order or hierarchy. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0019] like Figure 1 As shown, an embodiment of the present invention provides a method for preparing a bone implant material, comprising: Step S1: Prepare ceramic slurry using silicon nitride ceramic powder, dispersant, sintering aid, defoamer, binder and solvent as raw materials; Step S2: The ceramic slurry is freeze-cast to obtain the first ceramic blank; Step S3: Under vacuum conditions, the first ceramic preform is freeze-dried to obtain the second ceramic preform; Step S4: Under a protective gas atmosphere, the second ceramic preform is sintered to obtain the first ceramic preform. Step S5: Perform surface oxidation treatment on the first ceramic preform to obtain the second ceramic preform; wherein, the surface oxidation treatment temperature is 600℃ to 1100℃ and the time is 1h to 8h. Step S6: Modify the second ceramic preform with sol-gel to obtain the third ceramic preform; Step S7: Heat-treat the third ceramic preform to obtain a modified ceramic preform; wherein the heat treatment temperature is 500℃ to 1000℃ and the time is 1h to 5h. Step S8: Place the modified ceramic preform in a molten metal for pressure infiltration, and cool to room temperature to obtain the bone implant material.

[0020] This invention employs freeze casting and vacuum freeze drying to construct a silicon nitride ceramic preform with high connectivity and directional pore structure. After sintering in a protective atmosphere, a high-strength, low-defect ceramic framework is obtained. Subsequently, surface oxidation treatment at 600°C to 1100°C generates a dense and stable silica transition layer on the silicon nitride surface in situ. This transition layer not only effectively blocks the erosion of the ceramic matrix by body fluids, significantly improving the material's corrosion resistance, but also provides a highly active hydroxyl surface for subsequent sol-gel coatings, enhancing coating adhesion and uniformity. Based on this, a bioactive sol is deposited using the sol-gel method, and heat treatment at 500°C to 1000°C achieves densification and crystallization of the coating, forming a composite material with both bone-inducing and [other properties]. The nanoscale bioactive interface, possessing conductivity, sustained-release ion function, and antibacterial properties, significantly accelerates bone tissue regeneration and ensures excellent biocompatibility. Finally, the molten metal is introduced into the ceramic pores via pressure infiltration, forming a metal-ceramic composite bone implant material. After implantation, the slow influx of degradable metal ions from the implant material promotes bone healing. Once mature bone tissue is formed, the elastic modulus of the implant material matches that of the bone tissue, preventing stress shielding. The oxide layer and dense coating together construct multiple barriers, inhibiting metal corrosion and interfacial delamination, thereby achieving synergistic optimization of corrosion resistance, bone regeneration capacity, biocompatibility, mechanical fit, and long-term implantation stability. In summary, the bone implant material prepared by the method of this invention exhibits superior corrosion resistance, rapid bone tissue regeneration capacity, excellent biocompatibility, an elastic modulus matching that of bone tissue, and long-term implantation stability.

[0021] In some embodiments of the present invention, in step S1, the mass ratio of the silicon nitride ceramic powder, the dispersant, the sintering aid, the defoamer, the binder and the solvent is (10 to 70): (0.5 to 5): (0.5 to 5): (0.5 to 5): (0.5 to 5): (40 to 70).

[0022] In some embodiments of the present invention, step S1, which involves preparing a ceramic slurry using silicon nitride ceramic powder, dispersant, sintering aid, defoamer, binder, and solvent as raw materials, includes: Step S11: After mixing silicon nitride ceramic powder, dispersant, sintering aid and solvent, the mixture is subjected to a first ball milling process to obtain a first slurry; wherein the first ball milling process is performed at a speed of 80 rpm to 200 rpm for a time of 8 h to 24 h. Step S12: Add defoamer to the first slurry and stir under vacuum to obtain a second slurry; wherein the stirring speed is 20 rpm to 40 rpm and the time is 1 min to 10 min. Step S13: Add a binder to the second slurry and perform a second ball milling process to obtain a ceramic slurry; wherein the second ball milling process is performed at a speed of 80 rpm to 100 rpm for a time of 0.5 h to 3 h.

[0023] In this embodiment, the synergistic process of staged ball milling and vacuum defoaming not only achieves uniform dispersion of silicon nitride powder and thorough mixing of sintering aids, but also avoids binder degradation and bubble residue, significantly improving the stability of ceramic slurry.

[0024] In some embodiments of the present invention, in step S1, the dispersant includes at least one of tetramethylammonium hydroxide, ammonium polyacrylate, sodium polyacrylate, sodium hexametaphosphate, and BYK163; the sintering aid includes at least one of rare earth oxides, alumina, and silicon dioxide; the defoamer includes at least one of n-butanol, sec-butanol, and isobutanol; the binder includes at least one of polyvinyl alcohol, carboxymethyl cellulose, sodium alginate, polymethyl methacrylate, polyvinyl butyral, and agarose; and the solvent includes at least one of water and tert-butanol.

[0025] In some embodiments of the present invention, the temperature of the freeze casting is -10°C to -197°C, and the time is 1 hour to 8 hours; the temperature of the freeze drying is -20°C to -50°C, and the time is 12 hours to 36 hours.

[0026] In some embodiments of the present invention, in step S4, the protective gas atmosphere is selected from one of nitrogen atmosphere, argon atmosphere, helium atmosphere, neon atmosphere, krypton atmosphere, xenon atmosphere and radon atmosphere; the sintering temperature is 1500℃ to 2000℃ and the time is 1h to 4h.

[0027] In some embodiments of the present invention, step S6, wherein the sol-gel modification of the second ceramic preform includes: vacuum impregnating the second ceramic preform in a sol, followed by gelation treatment, and finally drying treatment; wherein the sol includes at least one of nano-silica, mesoporous bioglass sol, zinc oxide sol, strontium oxide sol, hydroxyapatite sol, and phosphate sol; the vacuum impregnation time is 5 min to 60 min, the gelation treatment temperature is 60°C, and the time is 2 h to 6 h; the drying treatment temperature is 80°C, and the time is 12 h to 24 h. In this embodiment, by precisely controlling the process parameters of vacuum impregnation-gelation-drying, a uniform modified layer is formed on the surface and within the pores of the ceramic preform using the sol, which not only improves the surface activity, biocompatibility, or mechanical properties of the ceramic, but also avoids cracking or structural damage of the preform during the modification process.

[0028] In some embodiments of the present invention, in step S8, the material of the molten metal is selected from at least one of magnesium, magnesium alloy, iron, iron alloy, zinc, and zinc alloy.

[0029] In some embodiments of the present invention, in step S8, the pressure of the pressure impregnation is 0.5 MPa to 10 MPa, and the time is 5 min to 60 min.

[0030] This invention also provides a bone implant material, which is prepared using the bone implant material preparation method described above.

[0031] Application of a bone implant material as described above in the preparation of bone implant patches, bone implant rods and complex bone implant components.

[0032] The bone implant materials provided in this invention can be used to prepare bone implant patches, bone implant rods and complex bone components, achieving integrated application of "structural adaptation, functional induction and long-term stability", significantly improving the clinical implantation success rate and reducing the risk of secondary surgery.

[0033] The present invention will be further described below with reference to specific embodiments.

[0034] Example 1 A1. Silicon nitride ceramic powder, dispersant, sintering aid, and solvent are mixed and subjected to a first ball milling process to obtain a first slurry; an antifoaming agent is added to the first slurry, and the mixture is stirred under vacuum to obtain a second slurry; a binder is added to the second slurry, and the mixture is subjected to a second ball milling process to obtain a ceramic slurry; wherein the particle size of the silicon nitride ceramic powder is 0.25 μm; the dispersant is tetramethylammonium hydroxide; and the sintering aid is composed of nano-yttrium oxide powder and nano-alumina powder in a molar ratio of 3... The composition is as follows: 5 components; the defoamer is n-butanol; the binder is agarose; the solvent is water; the mass ratio of the silicon nitride ceramic powder, the dispersant, the sintering aid, the defoamer, the binder, and the solvent is 30:1:1:0.5:1:66.5; the first ball milling treatment is performed at a speed of 140 rpm for 12 hours; the stirring treatment is performed at a speed of 30 rpm for 5 minutes; the second ball milling treatment is performed at a speed of 90 rpm for 0.5 hours.

[0035] A2. The ceramic slurry is cryogenically cast in a casting mold to obtain a first ceramic blank; the cryogenic casting temperature is -50°C and the time is 4 hours.

[0036] A3. Under vacuum conditions, the first ceramic blank is freeze-dried to obtain the second ceramic blank; the freeze-drying temperature is -20°C and the time is 24 hours.

[0037] A4. The second ceramic body is sintered under a nitrogen atmosphere to obtain the first ceramic preform; the pressure of nitrogen in the nitrogen atmosphere is 1 MPa, the temperature of the sintering treatment is 1850℃, and the time is 1 h.

[0038] A5. The first ceramic preform is subjected to surface oxidation treatment to obtain the second ceramic preform; wherein the surface oxidation treatment temperature is 800℃ and the time is 3h.

[0039] A6. The second ceramic preform is vacuum impregnated in a sol, then gelled, and finally dried to obtain the third ceramic preform; wherein the sol is nano-silica; the vacuum impregnation time is 30 min, the gelation temperature is 60℃ and the time is 4 h; and the drying temperature is 80℃ and the time is 18 h.

[0040] A7. The third ceramic preform is subjected to heat treatment to obtain a modified ceramic preform; wherein the heat treatment temperature is 700℃ and the time is 1h.

[0041] A8. The modified ceramic preform is placed in a molten metal for pressure infiltration and cooled to room temperature to obtain a bone implant material; wherein the molten metal is made of magnesium; the pressure for pressure infiltration is 0.5 MPa and the time is 20 min.

[0042] Example 2 A1. Silicon nitride ceramic powder, dispersant, sintering aid, and solvent are mixed and subjected to a first ball milling process to obtain a first slurry; an antifoaming agent is added to the first slurry, and the mixture is stirred under vacuum to obtain a second slurry; a binder is added to the second slurry, and the mixture is subjected to a second ball milling process to obtain a ceramic slurry; wherein the particle size of the silicon nitride ceramic powder is 0.25 μm; the dispersant is ammonium polyacrylate; and the sintering aid is composed of nano-yttrium oxide powder and nano-alumina powder in a molar ratio of 3: The composition is as follows: the defoamer is sec-butanol; the binder is polyvinyl alcohol; the solvent is water; the mass ratio of the silicon nitride ceramic powder, the dispersant, the sintering aid, the defoamer, the binder, and the solvent is 40:1.5:1:0.5:2:55; the first ball milling treatment is performed at a speed of 120 rpm for 24 hours; the stirring treatment is performed at a speed of 30 rpm for 5 minutes; and the second ball milling treatment is performed at a speed of 80 rpm for 3 hours.

[0043] A2. The ceramic slurry is cryogenically cast in a casting mold to obtain a first ceramic blank; the cryogenic casting temperature is -80°C and the time is 4 hours.

[0044] A3. Under vacuum conditions, the first ceramic blank is freeze-dried to obtain the second ceramic blank; the freeze-drying temperature is -50°C and the time is 24 hours.

[0045] A4. The second ceramic body is sintered under a nitrogen atmosphere to obtain the first ceramic preform; the pressure of nitrogen in the nitrogen atmosphere is 0.5 MPa, the sintering temperature is 1700℃, and the time is 2 hours.

[0046] A5. The first ceramic preform is subjected to surface oxidation treatment to obtain the second ceramic preform; wherein the surface oxidation treatment temperature is 1000℃ and the time is 8h.

[0047] A6. The second ceramic preform is vacuum impregnated in a sol, then gelled, and finally dried to obtain the third ceramic preform; wherein the sol is hydroxyapatite sol; the vacuum impregnation time is 20 min, the gelation temperature is 60℃ and the time is 4 h; and the drying temperature is 80℃ and the time is 18 h.

[0048] A7. The third ceramic preform is subjected to heat treatment to obtain a modified ceramic preform; wherein the heat treatment temperature is 750℃ and the time is 2h.

[0049] A8. The modified ceramic preform is placed in a molten metal for pressure infiltration and cooled to room temperature to obtain a bone implant material; wherein the molten metal is made of ZK60 magnesium alloy; the pressure for pressure infiltration is 1 MPa and the time is 10 min.

[0050] Example 3 A1. Silicon nitride ceramic powder, dispersant, sintering aid, and solvent are mixed and subjected to a first ball milling process to obtain a first slurry; an antifoaming agent is added to the first slurry, and the mixture is stirred under vacuum to obtain a second slurry; a binder is added to the second slurry, and the mixture is subjected to a second ball milling process to obtain a ceramic slurry; wherein the particle size of the silicon nitride ceramic powder is 0.25 μm; the dispersant is BYK163; and the sintering aid is composed of nano-yttrium oxide powder and nano-alumina powder in a molar ratio of 3:5. The composition is as follows: the defoamer is isobutanol; the binder is polyvinyl butyral; the solvent is tert-butanol; the mass ratio of the silicon nitride ceramic powder, the dispersant, the sintering aid, the defoamer, the binder, and the solvent is 50:2:1:0.5:2:44.5; the first ball milling treatment is performed at a speed of 200 rpm for 8 hours; the stirring treatment is performed at a speed of 30 rpm for 1 minute; and the second ball milling treatment is performed at a speed of 100 rpm for 1 hour.

[0051] A2. The ceramic slurry is cryogenically cast in a casting mold to obtain a first ceramic blank; the cryogenic casting temperature is -197°C and the time is 4 hours.

[0052] A3. Under vacuum conditions, the first ceramic blank is freeze-dried to obtain the second ceramic blank; the freeze-drying temperature is -30°C and the time is 24 hours.

[0053] A4. The second ceramic body is sintered under a nitrogen atmosphere to obtain the first ceramic preform; the pressure of nitrogen in the nitrogen atmosphere is 1.5 MPa, the sintering temperature is 2000℃, and the time is 4 hours.

[0054] A5. The first ceramic preform is subjected to surface oxidation treatment to obtain the second ceramic preform; wherein the surface oxidation treatment temperature is 900℃ and the time is 6h.

[0055] A6. The second ceramic preform is vacuum impregnated in a sol, then gelled, and finally dried to obtain the third ceramic preform; wherein the sol is hydroxyapatite sol; the vacuum impregnation time is 10 min, the gelation temperature is 60℃ and the time is 4 h; and the drying temperature is 80℃ and the time is 18 h.

[0056] A7. The third ceramic preform is subjected to heat treatment to obtain a modified ceramic preform; wherein the heat treatment temperature is 750℃ and the time is 2h.

[0057] A8. The modified ceramic preform is placed in a molten metal for pressure infiltration and cooled to room temperature to obtain a bone implant material; wherein the molten metal is made of ZK60 magnesium alloy; the pressure for pressure infiltration is 1 MPa and the time is 10 min.

[0058] Comparative Example 1 (without surface oxidation treatment) Silicon nitride ceramic powder, dispersant, sintering aid, and solvent are mixed and then subjected to a first ball milling process to obtain a first slurry. An antifoaming agent is added to the first slurry, and the mixture is stirred under vacuum to obtain a second slurry. A binder is added to the second slurry, and the mixture is subjected to a second ball milling process to obtain a ceramic slurry. The silicon nitride ceramic powder has a particle size of 0.25 μm; the dispersant is tetramethylammonium hydroxide; and the sintering aid is composed of nano-yttrium oxide powder and nano-alumina powder in a molar ratio of 3:5. Composition: The defoamer is n-butanol; the binder is agarose; the solvent is water; the mass ratio of the silicon nitride ceramic powder, the dispersant, the sintering aid, the defoamer, the binder, and the solvent is 30:1:1:0.5:1:66.5; the first ball milling treatment is performed at a speed of 140 rpm for 12 hours; the stirring treatment is performed at a speed of 30 rpm for 5 minutes; the second ball milling treatment is performed at a speed of 90 rpm for 0.5 hours.

[0059] The ceramic slurry is cryogenically cast in a casting mold to obtain a first ceramic blank; the cryogenic casting temperature is -50°C and the time is 4 hours.

[0060] The first ceramic blank was freeze-dried under vacuum conditions to obtain the second ceramic blank; the freeze-drying temperature was -20°C and the time was 24 hours.

[0061] The second ceramic body is sintered under a nitrogen atmosphere to obtain the first ceramic preform; the nitrogen pressure in the nitrogen atmosphere is 1 MPa, the sintering temperature is 1850℃, and the time is 1 h.

[0062] The first ceramic preform is vacuum impregnated in a sol, then gelled, and finally dried to obtain the second ceramic preform; wherein the sol is nano-silica; the vacuum impregnation time is 30 min, the gelation temperature is 60℃ and the time is 4 h; and the drying temperature is 80℃ and the time is 18 h.

[0063] The second ceramic preform is subjected to heat treatment to obtain a modified ceramic preform; wherein the heat treatment temperature is 700℃ and the time is 1h.

[0064] The modified ceramic preform was placed in a molten metal for pressure infiltration and cooled to room temperature to obtain a bone implant material; wherein the molten metal was made of magnesium; the pressure for pressure infiltration was 0.5 MPa and the time was 20 min.

[0065] Comparative Example 2 (without sol-gel modification and subsequent heat treatment) Silicon nitride ceramic powder, dispersant, sintering aid, and solvent are mixed and then subjected to a first ball milling process to obtain a first slurry. An antifoaming agent is added to the first slurry, and the mixture is stirred under vacuum to obtain a second slurry. A binder is added to the second slurry, and the mixture is subjected to a second ball milling process to obtain a ceramic slurry. The silicon nitride ceramic powder has a particle size of 0.25 μm; the dispersant is tetramethylammonium hydroxide; and the sintering aid is composed of nano-yttrium oxide powder and nano-alumina powder in a molar ratio of 3:5. Composition: The defoamer is n-butanol; the binder is agarose; the solvent is water; the mass ratio of the silicon nitride ceramic powder, the dispersant, the sintering aid, the defoamer, the binder, and the solvent is 30:1:1:0.5:1:66.5; the first ball milling treatment is performed at a speed of 140 rpm for 12 hours; the stirring treatment is performed at a speed of 30 rpm for 5 minutes; the second ball milling treatment is performed at a speed of 90 rpm for 0.5 hours.

[0066] The ceramic slurry is cryogenically cast in a casting mold to obtain a first ceramic blank; the cryogenic casting temperature is -50°C and the time is 4 hours.

[0067] The first ceramic blank was freeze-dried under vacuum conditions to obtain the second ceramic blank; the freeze-drying temperature was -20°C and the time was 24 hours.

[0068] The second ceramic body is sintered under a nitrogen atmosphere to obtain the first ceramic preform; the nitrogen pressure in the nitrogen atmosphere is 1 MPa, the sintering temperature is 1850℃, and the time is 1 h.

[0069] The first ceramic preform is subjected to surface oxidation treatment to obtain the second ceramic preform; wherein the surface oxidation treatment temperature is 800℃ and the time is 3h.

[0070] The second ceramic preform is placed in a molten metal for pressure infiltration and cooled to room temperature to obtain a bone implant material; wherein the molten metal is made of magnesium; the pressure for pressure infiltration is 0.5 MPa and the time is 20 min.

[0071] Comparative Example 3 In this comparative example, the bone implant material was a pure magnesium rod.

[0072] Comparative Example 4 In this comparative example, the bone implant material was a pure silicon nitride ceramic rod.

[0073] Effect Example The hardness, elastic modulus and flexural strength of the bone implant materials prepared in Examples 1 to 3 were tested, and the results are shown in Table 1. It can be seen from Table 1 that the flexural strength of the bone implant materials prepared in Examples 1 to 3 is high, and their hardness and elastic modulus are close to those of human bone (hardness 30HB, elastic modulus 3GPa to 18GPa).

[0074] Table 1

[0075] The bone implant materials of Examples 1 to 3 and Comparative Examples 1 to 3 were placed in simulated body fluid at 37°C to test their static corrosion rate. The results are shown in Table 2. Compared with Comparative Examples 1 and 3, the static corrosion rate of the bone implant materials of Examples 1 to 3 was slower, indicating that the bone implant materials of Examples 1 to 3 have better corrosion resistance in simulated body fluid.

[0076] Table 2

[0077] The bone implant material from Example 1 was made into bone implant pieces and implanted into mice with cortical bone defects. The flexural strength retention rate, elastic modulus, degradation, and bone growth of the bone implant pieces during the bone repair stage were statistically analyzed. The results are shown in Table 3. As can be seen from Table 3, after 100 days of implantation into mice with cortical bone defects, the bone implant pieces made from the bone implant material from Example 1 formed mature bone tissue. At this time, the flexural strength retention rate of the bone implant pieces was 52%, and the flexural strength was higher than the standard for cortical bone (>50MPa). The elastic modulus was 18GPa, and the elastic modulus matched the elastic modulus of cortical bone well, meeting the requirements for long-term implantation stability.

[0078] The bone implant materials from Examples 1 to 3 and Comparative Example 4 were made into bone implant patches and implanted into mice with tibial defects. The bone volume fraction, trabecular thickness (Tb.Th), and number of trabecular bones (Tb.N) were counted after 8 weeks. The results are shown in Table 4. As can be seen from Table 4, compared with Comparative Example 4, Examples 1 to 3 had higher bone volume fraction, greater trabecular thickness, and more trabecular bones, indicating that the bone implant materials prepared in Examples 1 to 3 can achieve bone tissue regeneration more quickly.

[0079] Table 3

[0080] Table 4

[0081] MC3T3-E1 osteogenic precursor cells were seeded onto the surface of the bone implant materials in Examples 1 to 3 and Comparative Examples 2 and 4, respectively, and cultured in osteogenic induction medium. The cell viability of the MC3T3-E1 osteogenic precursor cells after 2 days of culture was detected by CCK-8 assay. The results are shown in Table 5. As can be seen from Table 5, compared with Comparative Examples 2 and 4, the cell viability of the corresponding MC3T3-E1 osteogenic precursor cells in Examples 1 to 3 is higher, indicating that the bone implant materials prepared in Examples 1 to 3 have better biocompatibility.

[0082] Table 5

[0083] It should be noted that the blank control group in Table 5 represents the test results after MC3T3-E1 osteogenic progenitor cells were cultured directly in osteogenic induction medium for 2 days. The data in Tables 1 to 5 are the average values ​​of 20 replicate experiments.

[0084] While the present invention has been disclosed above, its scope of protection is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, and all such changes and modifications will fall within the scope of protection of the present invention.

Claims

1. A method for preparing a bone implant material, characterized in that, include: Step S1: Prepare ceramic slurry using silicon nitride ceramic powder, dispersant, sintering aid, defoamer, binder and solvent as raw materials; Step S2: The ceramic slurry is freeze-cast to obtain the first ceramic blank; Step S3: Under vacuum conditions, the first ceramic preform is freeze-dried to obtain the second ceramic preform; Step S4: Under a protective gas atmosphere, the second ceramic preform is sintered to obtain the first ceramic preform. Step S5: Perform surface oxidation treatment on the first ceramic preform to obtain the second ceramic preform; wherein, the surface oxidation treatment temperature is 600℃ to 1100℃; Step S6: Modify the second ceramic preform with sol-gel to obtain the third ceramic preform; Step S7: The third ceramic preform is subjected to heat treatment to obtain a modified ceramic preform; wherein the heat treatment temperature is 500℃ to 1000℃. Step S8: Place the modified ceramic preform in a molten metal for pressure infiltration, and cool to room temperature to obtain the bone implant material.

2. The method for preparing bone implant material according to claim 1, characterized in that, In step S1, the mass ratio of the silicon nitride ceramic powder, the dispersant, the sintering aid, the defoamer, the binder and the solvent is (10 to 70): (0.5 to 5): (0.5 to 5): (0.5 to 5): (0.5 to 5): (40 to 70).

3. The method for preparing the bone implant material according to claim 1, characterized in that, In step S1, the dispersant includes at least one of tetramethylammonium hydroxide, ammonium polyacrylate, sodium polyacrylate, sodium hexametaphosphate, and BYK163; the sintering aid includes at least one of rare earth oxides, alumina, and silica; the defoamer includes at least one of n-butanol, sec-butanol, and isobutanol; the binder includes at least one of polyvinyl alcohol, carboxymethyl cellulose, sodium alginate, polymethyl methacrylate, polyvinyl butyral, and agarose; and the solvent includes at least one of water and tert-butanol.

4. The method for preparing the bone implant material according to claim 1, characterized in that, The temperature for cryogenic casting is between -10°C and -197°C; the temperature for freeze drying is between -20°C and -50°C.

5. The method for preparing bone implant material according to claim 1, characterized in that, In step S4, the protective gas atmosphere is selected from one of nitrogen atmosphere, argon atmosphere, helium atmosphere, neon atmosphere, krypton atmosphere, xenon atmosphere and radon atmosphere; the sintering treatment temperature is 1500℃ to 2000℃ and the time is 1h to 4h.

6. The method for preparing the bone implant material according to claim 1, characterized in that, In step S6, the sol-gel modification of the second ceramic preform includes: vacuum impregnating the second ceramic preform in a sol, followed by gelation treatment, and finally drying treatment; wherein the sol includes at least one of nano-silica, mesoporous bioglass sol, zinc oxide sol, strontium oxide sol, hydroxyapatite sol, and phosphate sol.

7. The method for preparing bone implant material according to claim 1, characterized in that, In step S8, the material of the molten metal is selected from at least one of magnesium, magnesium alloy, iron, iron alloy, zinc, and zinc alloy.

8. The method for preparing the bone implant material according to claim 1, characterized in that, In step S8, the pressure of the pressure impregnation is 0.5 MPa to 10 MPa, and the time is 5 min to 60 min.

9. A bone implant material, characterized in that, It is prepared using the method for preparing bone implant materials as described in any one of claims 1 to 8.

10. The use of the bone implant material as described in claim 9 in the preparation of bone implant patches, bone implant rods and complex bone implant components.

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