CN112704582B - Preparation method of customizable regenerated porous nano-material 3D printed femoral head - Google Patents

Abstract

A preparation method of a customizable regenerative porous nano material 3D printing femoral head. The method comprises the steps of obtaining femoral head image data by CT scanning, establishing a three-dimensional model suitable for a transplanted joint according to the CT image data, respectively using a metal nano composite material and a beta tricalcium phosphate-polypyrrole-biotin composite material as femoral head base materials, printing layer by layer in a body-centered cubic porous structure, adding icaritin-biotin-polylactic acid microspheres for carrying out ball loading treatment, and covering a biological ceramic coating on the surface.

Description

A preparation method for 3D-printed femoral head with customizable regenerated porous nanomaterials

technical field

The present invention designs a medical implant prosthesis, in particular to a customized and regenerable multi-component porous multi-layer nanocomposite 3D printing hip joint femoral head.

Background technique

The hip joint is one of the important joints to maintain the daily activities of the human body, and it is also easy to damage and cause diseases. At present, hip replacement surgery is an effective means to treat hip joint diseases. In recent years, with the development of 3D printing technology, scholars There has been great interest in the optimal design of artificial hip joint prostheses. Many experts and scholars have made outstanding contributions to the development of artificial hip joints and have achieved remarkable achievements. Artificial hip joint prostheses require good Biocompatibility, flexibility, load-carrying capacity, stability and less friction and wear. With the continuous progress of material science and biomechanics, great breakthroughs have been made in the research of artificial hip joint prostheses in terms of materials, structural shapes, fixation methods, and optimal design.

The clinical problems of hip replacement can be divided into three aspects, including the patient's own physical condition, the doctor's operation technique during the operation and the artificial hip prosthesis, which affect the long-term stability and service life of the artificial hip prosthesis. The two main factors are bone resorption and aseptic loosening. Studies have found that there will be pain after surgery. The main reason is that stress concentration and stress shielding occur after the prosthesis is implanted into the human body.

Compared with the traditional method, the hip femoral head printed by the invention adopts the body-centered cubic structure to print, which optimizes the mechanical properties, anti-fatigue performance and stability. Among the orthopedic scaffold materials, polyamide 6 has excellent toughness, friction resistance and biocompatibility. Their addition improves drug-carrying capacity and sustained-release performance, and can stimulate bone marrow mesenchymal stem cells to participate in bone repair around the prosthesis. To achieve the regeneration of the femoral head of the hip joint, avoiding the risk of secondary surgery. Also relevant to the present invention are the following documents:

1. Liu Lutan. Experimental study on the effect of different porosity of 3D printed porous titanium implants on bone ingrowth [J]. Journal of Bengbu Medical College. 2019.09:1153-1157.

This paper mainly describes the effect of different porosity of porous titanium implants on the effect of bone ingrowth by observing the bone ingrowth of 3D printed porous titanium implants with different porosity in rabbit experiments.

2. Li Shubo. Numerical simulation and experimental study on mechanical properties of 3D printed hip prosthesis porous structure [D]. Jilin University. 2020,06.

It is mainly described that 4 different unit structures are set up, geometric models and finite element models are established, and the compression experiments are simulated to carry out finite element simulation analysis to explore the differences in mechanical properties of different porous structures.

3. Liu Zin, Du Bin. Porous β-tricalcium phosphate-polypyrrole-biotin-icariin microsphere composite scaffold promotes the recruitment of bone marrow mesenchymal stem cells[J]. China Tissue Engineering Research.2020.(34 ): 5532-5537.

It is mainly described that the porous β-tricalcium phosphate-polypyrrole-biotin composite scaffold has further improved drug-loading capacity and sustained-release performance compared with traditional sustained-release scaffolds, and has good mechanical strength, and may have better recruitment of bone marrow mesenchyme. Stem cells are involved in the role of bone repair around the scaffold.

4. Liu Junhuan. Preparation of boron-containing CaP bioceramic coating by laser cladding on titanium alloy surface [D]. University of South China. 2019.05

This paper mainly describes the preparation of CaP bioceramic coatings with different boron content by laser cladding method, and studies the effect of CaB ₆ content on the corrosion resistance and biological activity of the cladding layer.

5. Hu Yafei. Preparation and properties of silver/hydroxyapatite/polyamide 6 composites [D]. Taiyuan University of Technology. 2018.06

The Ag/HA/PA6 composites with different contents were prepared by solution blending method with different complexing agents, and their structure, crystallization properties, mechanical properties and friction properties were analyzed and studied.

6. Oshkour A A, Osman N A A, Davoodi M M, et al. Finite element analysis on longitudinal and radial functionally graded femoral prosthesis[J]. International Journal for Numerical Methods in Biomedical Engineering, 2013, 29(12): 1412-1427.

The influence of different geometric parameters on the gradient femoral stem is mainly described, and the finite element analysis of the gradient femoral stem is carried out. The results show that increasing the gradient index will increase the strain energy in the prosthesis and reduce the stress shielding phenomenon.

7. Jetté B, Brailovski V, Dumas M, et al. Femoral stem incorporating adiamond cubic lattice structure: Design, manufacturing and testing[J]. Journal of the Mechanical Behavior of Biomedical Materials, 2018, 77: 58-72.

This paper mainly describes the research on the porous hip joint prosthesis by the method of combining finite element and experiment. The results show that the porous hip joint prosthesis can promote the ingrowth of bone tissue and reduce the stress shielding.

8. Lim mahakhun S, O1oyede A, Chantarapanich N, et al.Altemative desgnsof load-sharing cobalt chromium graded femoral stems[J],Materials TodayCommunications,2017,12:1-10.

This paper mainly describes a hip joint prosthesis with a gradient pore structure in the middle, and the finite element calculation and three-point bending experiments are carried out on its mechanical properties and stress transfer properties.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a preparation method for 3D printing femoral head with customizable regenerated porous nanomaterials, which solves the problems of low utilization rate of artificial bone components, insufficient strength, toughness and wear resistance of femoral heads, and the multi-layered The materials used in the structure can stimulate the repair and growth of bone cells, so that the products can meet the affinity of human bones while reducing the stress concentration and stress shielding of implants. The products printed by 3D method are more in line with the bone characteristics of the human body. The existence of its porous structure not only ensures the mechanical properties, but also realizes the secondary growth of bones.

The present invention is implemented through the following technical solutions:

The image data of the hip joints on both sides of the human body were scanned with CT, and a three-dimensional model of the femoral head of the damaged hip joint was established by mirroring according to the CT image. 1. The β-tricalcium phosphate-polypyrrole-biotin composite material was used as the 3D printing material 2. The femoral head matrix was layered with materials 1 and 2 in a body-centered cubic porous structure, and then the epimedium was loaded on the matrix. Biotin-biotin-polylactic acid microspheres, and finally, the surface of the printed body is coated with a bioceramic coating and polished. The specific scheme is as follows:

1. Bone modeling

The CT scanning equipment is used to scan the hip joint and the damaged part of the hip femoral head to obtain image data. According to the damaged hip femoral head, the size and shape of the femoral head that can be transplanted are redesigned using 3D software.

2. Preparation of Metal Nanomix Powder Materials

Take Ti powder (purity of 99.9%), Mg particles (purity of 99.8%), Si particles (purity of 99.8%), Ca particles and Mo powder in a molar ratio of (30-50): (15-25): ( 30-40): (10-20): (0.1-0.3) After mixing evenly, put it into a high-energy ball mill for processing, so that it can obtain 80-100nm grain size ultra-fine metal nano-mixture powder material.

3. Preparation of β-tricalcium phosphate-polypyrrole-biotin composites

The ratio of deionized water, sodium polyacrylate, β-tricalcium phosphate, methylol propylene, and cellulose by mass fraction is (1-1.2): (0.8-1): (2-5): (1-1.5): (1.2-1.6) Mix them into a closed container, add equal volumes of 0.1mol/L pyrrole and 0.2mol/L polyferric chloride, mix and stir for 35min, separate the polymer, wash with deionized water, and finally dry the finished product And put it into a ball mill for processing to obtain a β-tricalcium phosphate-polypyrrole-biotin composite material with a grain size of 80-100 nm.

The surface of β-tricalcium phosphate-polypyrrole-biotin composite bone is rough and regular in shape, with crest-like bulges, many pores, good connectivity between pores, large microscopic surface area, and a small amount of metal-like crystal luster can be seen on the bone surface under scanning electron microscope. The mixture of pyrrole and tricalcium phosphate can endow the scaffold with electrical conductivity as a whole, and its surface is suitable for the adhesion and growth of various cells. Through a chemical reaction synthesis method, polypyrrole is used as avidin to form a β-tricalcium phosphate-polypyrrole-biotin structure, and the multi-target binding ability of biotin is used to improve the binding ability of the scaffold to osteoinductive factors.

4. Preparation of icariin–biotin–polylactic acid microspheres

Put equal amounts of biotin, icariin, 1-hydroxybenzotriazole and 4-dimethylaminopyridine in the polyamino acid solution, stir at room temperature, cool to 0 °C, and then increase the temperature to 24 °C after dehydration. Fully react at -26°C, wash with deionized water, suspend the complex in absolute ethanol, filter by heating, wash twice with hot absolute ethanol, and dry to obtain the icariin-biotin complex.

The polylactic acid-glycolic acid copolymer, polyamino acid, distilled water, and icariin-biotin complex by mass fraction are (24.6-25.3): (24.8-25.4): (1.8-2.6): (4.8-5.3) Mixing, ultrasonic for 15 min, horn vibration frequency 40-100 kHz, amplitude 30-100 μm, slowly drop 10 g/L polyvinyl alcohol solution into the above mixed solution for emulsification operation, ultrasonic for 15 min to obtain icariin-biotin / Polylactic acid-glycolic acid copolymer double emulsion, finally centrifuged at a high speed of 12000r/min for 20min, filtered, washed twice with phosphate buffered saline, centrifuged the obtained suspension to remove the precipitate, put it in a freeze dryer to dry, and obtained icariin - Biotin-polylactic acid microspheres, the diameter of the microspheres is in the range of 2-20 μm.

5. Preparation of silver-hydroxyapatite-polyamide 6 composites

The HA/PA6 composite material was prepared by the method of complexing and dissolving the complexing agent. First, the CaCl ₂ and C ₂ H ₅ OH were mixed and stirred at a molar ratio of 1:5 in a closed drying container for 10 minutes, and the temperature was set at 68-72 ℃, the content of hydroxyapatite (HA) is set at 40% and mixed with polyamide 6 (PA6), then placed in the above container and stirred for 20min to obtain HA/PA6 composite material, and then plasma reduction method is used to give the above HA/PA6 composite material. The PA6 composite material is loaded with silver, the silver content is set at 0.6% and mixed with the HA/PA6 composite material, and then 5-20% glass fiber is added for mixing and stirring, and finally the finished product is dried and placed in a ball mill to obtain a grain size of 80-100nm Ag/HA/PA6 composite.

6. Using 3D printing technology to print the femoral head

The metal nano-mixture powder material and the silver-hydroxyapatite-polyamide 6 composite material powder were fully mixed according to the mass fraction ratio of 3:1, and the obtained powder was named as material 1, and the β-tricalcium phosphate-polyamide 6 composite material was The pyrrole-biotin powder is named as material 2, and the icariin-biotin-polylactic acid microsphere powder is named as material 3, so far the preparation work is completed.

The simulated 3D model was imported into a 3D printer, and a spheroid with a diameter of 2-2.2 cm was printed on the auxiliary support using the selective laser melting technology (Selectivelaser melting, SLM), which was used as the "core" of the femoral head. The diameter is set to 120-150nm, the printing speed is set to 80-100mm/min, the printed structure is set to a body-centered cubic porous structure, the pore size is set to 600-650μm, the porosity is set to 45%-55%, and the pillar diameter is set to Design at 1000-1200μm, and then use material 2 to print 6-8mm thick on the basis of the femoral "inner core" with the rotation and movement of the auxiliary support. As the second layer, the nozzle diameter is set to 120-150nm, and the printing speed is set to 80-100mm/min, using the body-centered cubic porous structure for printing, the pore size is set at 600-650μm, the porosity is set at 45%-55%, and the pillar diameter is designed at 1000-1200μm, and then use SLM technology to use material 1 in On the basis of material 2, a thickness of 1-1.2cm is printed. As the third layer, the nozzle diameter is set to 120-150nm, the printing speed is set to 80-100mm/min, and the body-centered cubic porous structure is used for printing. The pore size is set at 600-650μm, the porosity is set at 45%-55%, the diameter of the pillar is designed at 1000-1200μm, the ultrasonic vibration horn is added during the printing process, the vibration frequency is 80-100kHz, the amplitude is 20-150μm, and the tool head is away from the axis of the laser head 40-50mm, the semi-finished femoral head is now completed. Take the semi-finished femoral head off the auxiliary bracket and put it into a centrifuge tube, add the suspension of material 3 and 10% gelatin, centrifuge at low speed for 10 min, freeze for 24 h, and carry out femoral head loading. After ball treatment, the hydroxyapatite (HA), β-tricalcium phosphate and CaB ₆ powders were weighed with an electronic balance at a ratio of 47:48:5, and the three powders were mixed with a ball mill and fully ground. is 30nm, the purity is 99.9%, the particle size of CaB ₆ powder is 45nm, the particle size of β-tricalcium phosphate powder is 30nm, the purity is 99.8%, and 0.1% isopropanol is used as a binder for mixing and stirring for 5min, and the above mixed powder is prepared into The paste with a certain viscosity is applied to the surface of the femoral head, and the powder thickness of the preset layer is 4-6 mm. After standing at room temperature for 24 hours, it is placed in a vacuum drying oven to dry for 2 hours. The temperature of the vacuum drying oven is set to 45 ℃. The laser cladding method combines the femoral head with the paste. The laser power is set to P=1.2KW, the scanning speed V=15mm/s, the spot diameter is 3.0mm, the overlap rate is 40%, and the argon gas flow rate is 10L/min. The bioceramic coating is prepared, and finally the molded product is polished to reduce the surface roughness of the material.

Description of drawings:

Figure 1 is a schematic diagram of the material layering of the 3D printed hip femoral head. In Figure 1, 1 is a metal nanocomposite core; 2 is a β-tricalcium phosphate-polypyrrole-biotin composite; 3 is a metal nanocomposite; 4 is a Bioceramic coating.

Detailed ways:

Step 1: Use CT scanning equipment to scan the hip joint and the damaged part of the hip femoral head to obtain image data. According to the damaged hip femoral head, use 3D software to redesign the size and shape of the hip femoral head that can be transplanted.

Step 2: Take Ti powder (purity 99.9%), Mg particles (purity 99.8%), Si particles (purity 99.8%), Ca particles, Mo powder in molar ratio (30-50): (15- 25): (30-40): (10-20): (0.1-0.3) After mixing evenly, put it into a high-energy ball mill for processing to obtain 80-100nm grain size ultra-fine composite powder.

The third step: deionized water, sodium polyacrylate, β-tricalcium phosphate, methylol propylene, and cellulose are in a mass fraction ratio of (1-1.2): (0.8-1): (2-5): (1 -1.5): (1.2-1.6) Mix and put into a closed container, add equal volume of 0.1mol/L pyrrole and 0.2mol/L polyferric chloride, mix and stir for 35min, separate the polymer, wash with deionized water, and finally The finished product is dried and processed in a ball mill to obtain a β-tricalcium phosphate-polypyrrole-biotin composite material with a grain size of 80-100 nm.

The fourth step: put equal amounts of biotin, icariin, 1-hydroxybenzotriazole and 4-dimethylaminopyridine in the polyamino acid solution, stir at room temperature, cool to 0°C, and dehydrate the solution. The temperature was raised to 24-26 °C for a full reaction, washed with deionized water, the complex was suspended in absolute ethanol, filtered by heating, washed twice with hot absolute ethanol, and dried to obtain icariin-biological element complex.

The polylactic acid-glycolic acid copolymer, polyamino acid, distilled water, and icariin-biotin complex by mass fraction are (24.6-25.3): (24.8-25.4): (1.8-2.6): (4.8-5.3) Mixing, ultrasonic for 15 min, horn vibration frequency 40-100 kHz, amplitude 30-100 μm, slowly drop 10 g/L polyvinyl alcohol solution into the above mixed solution for emulsification operation, ultrasonic for 15 min to obtain icariin-biotin / Polylactic acid-glycolic acid copolymer double emulsion, finally centrifuged at a high speed of 12000r/min for 20min, filtered, washed twice with phosphate buffered saline, centrifuged the obtained suspension to remove the precipitate, put it in a freeze dryer to dry, and obtained icariin - Biotin-polylactic acid microspheres, the diameter of the microspheres is in the range of 2-20 μm.

The sixth step: prepare the HA/PA6 composite material by the method of complexing and dissolving the complexing agent, firstly, in a closed drying container, the molar ratio of CaCl ₂ and C ₂ H ₅ OH is 1:5 for mixing and stirring for 10 minutes, and the temperature is set At 68-72 ℃, the content of hydroxyapatite (HA) is set at 40%, mixed with polyamide 6 (PA6), and then placed in the above container and stirred for 20 minutes to obtain HA/PA6 composite material, and then the plasma reduction method is used. The above HA/PA6 composite material is loaded with silver, the silver content is set at 0.6% and mixed with the HA/PA6 composite material, and then 5-20% of glass fiber is added for mixing and stirring, and finally the finished product is dried and put into a ball mill for processing. Ag/HA/PA6 composites with a grain size of 80-100 nm.

The seventh step: the metal nano-mixture powder material and the silver-hydroxyapatite-polyamide 6 composite material are fully mixed according to the mass fraction ratio of 3:1, the obtained powder is named as material 1, and the β-phosphoric acid triphosphate Calcium-polypyrrole-biotin is named as material 2, and icariin-biotin-polylactic acid microspheres are named as material 3, so far the preparation work is completed.

The simulated 3D model was imported into a 3D printer, and a spheroid with a diameter of 2-2.2 cm was printed on the auxiliary support using the selective laser melting technology (Selectivelaser melting, SLM), which was used as the "core" of the femoral head. The diameter is set to 120-150nm, the printing speed is set to 80-100mm/min, the printed structure is set to a body-centered cubic porous structure, the pore size is set to 600-650μm, the porosity is set to 45%-55%, and the pillar diameter is set to Design at 1000-1200μm, and then use material 2 to print 6-8mm thick on the basis of the femoral "inner core" with the rotation and movement of the auxiliary support. As the second layer, the nozzle diameter is set to 120-150nm, and the printing speed is set to 80-100mm/min, using the body-centered cubic porous structure for printing, the pore size is set at 600-650μm, the porosity is set at 45%-55%, and the pillar diameter is designed at 1000-1200μm, and then use SLM technology to use material 1 in On the basis of material 2, a thickness of 1-1.2cm is printed. As the third layer, the nozzle diameter is set to 120-150nm, the printing speed is set to 80-100mm/min, and the body-centered cubic porous structure is used for printing. The pore size is set at 600-650μm, the porosity is set at 45%-55%, the diameter of the pillar is designed at 1000-1200μm, the ultrasonic vibration horn is added during the printing process, the vibration frequency is 80-100kHz, the amplitude is 20-150μm, and the tool head is away from the axis of the laser head 40-50mm, the semi-finished femoral head is now completed. Take the semi-finished femoral head off the auxiliary bracket and put it into a centrifuge tube, add the suspension of material 3 and 10% gelatin, centrifuge at low speed for 10 min, freeze for 24 h, and carry out femoral head loading. Ball handling.

Step 8: Relieve the femoral head after the ball loading treatment, and then weigh the hydroxyapatite (HA), β-tricalcium phosphate and CaB ₆ powders with an electronic balance at a ratio of 47:48:5, respectively, and weigh them. Mix the three powders and grind them thoroughly with a ball mill to obtain HA powder with a particle size of 30 nm and a purity of 99.9%, CaB ₆ powder with a particle size of 45 nm, beta tricalcium phosphate powder with a particle size of 30 nm and a purity of 99.8%, using 0.1% isopropyl Alcohol is used as a binder to mix and stir for 5 minutes, and the above mixed powder is prepared into a paste with a certain viscosity and coated on the surface of the femoral head. The thickness of the powder in the preset layer is 4-6 mm. After standing at room temperature for 24 hours, put it into vacuum drying Dry in the box for 2h, set the temperature of the vacuum drying box to 45℃, combine the femoral head with the paste by laser cladding, set the laser power P=1.2KW, the scanning speed V=15mm/s, the spot diameter is 3.0mm, The overlap ratio is 40%, and the flow rate of argon gas is 10L/min to prepare the bioceramic coating. Finally, the molded product is polished to reduce the surface roughness of the material.

Claims (1)

1. A preparation method for 3D printing a femoral head with customizable regenerated porous nanomaterials, is characterized in that: obtain femoral head image data with CT scan, establish a three-dimensional model suitable for the transplanted joint according to the CT image data, and use metal nanocomposite materials and β The tricalcium phosphate-polypyrrole-biotin composite material was used as the matrix material of the femoral head, and then icariin-biotin-polylactic acid microspheres were added to carry out the ball loading treatment, and the femoral head was printed layer by layer with a body-centered cubic porous structure. And the surface is covered with bioceramic material, and the specific process steps for the preparation of the femoral head are: (a) Bone modeling: CT scanning equipment is used to scan the hip joint and the damaged part of the hip joint to obtain image data. According to the damaged hip joint femoral head, the size and shape of the hip femoral head that can be transplanted are redesigned using 3D software. ; (b) Preparation of metal nanocomposites: take Ti powder with a purity of 99.9%, Mg particles with a purity of 99.8%, Si particles with a purity of 99.8%, Ca particles, and Mo powder in a molar ratio of (30-50) : (15-25): (30-40): (10-20): (0.1-0.3) After mixing evenly, put it into a ball mill for processing to obtain 80-100nm grain size ultra-fine composite powder; (c) Preparation of β-tricalcium phosphate-polypyrrole-biotin composite material: The ratio of deionized water, sodium polyacrylate, β-tricalcium phosphate, methylol propylene, and cellulose by mass fraction is (1-1.2): (0.8-1): (2-5): (1-1.5): (1.2-1.6) Mix and put into a closed container, add equal volume of 0.1mol/L pyrrole and 0.2mol/L polyferric chloride and mix Stir for 35min, separate the polymer, wash with deionized water, and finally dry the finished product and put it into a ball mill for processing to obtain a β-tricalcium phosphate-polypyrrole-biotin composite material with a grain size of 80-100nm; (d) Put equal amounts of biotin, icariin, 1-hydroxybenzotriazole and 4-dimethylaminopyridine in the polyamino acid solution, stir at room temperature, cool to 0°C, perform dehydration treatment and increase the temperature The temperature was raised to 24-26°C for a full reaction, washed with deionized water, the complex was suspended in absolute ethanol, heated and filtered, washed twice with hot absolute ethanol, and dried to obtain icariin-biological complex; The polylactic acid-glycolic acid copolymer, polyamino acid, distilled water, and icariin-biotin complex by mass fraction are (24.6-25.3): (24.8-25.4): (1.8-2.6): (4.8-5.3) Mixing, ultrasonic for 15 min, horn vibration frequency 40-100 kHz, amplitude 30-100 μm, slowly drop 10 g/L polyvinyl alcohol solution into the above mixed solution for emulsification operation, ultrasonic for 15 min to obtain icariin-biotin / Polylactic acid-glycolic acid copolymer double emulsion, finally centrifuged at a high speed of 12000r/min for 20min, filtered, washed twice with phosphate buffered saline, centrifuged the obtained suspension to remove the precipitate, put it in a freeze dryer to dry, and obtained icariin - Biotin-polylactic acid microspheres, the diameter of the microspheres is in the range of 2-20 μm; (e) Preparation of silver-hydroxyapatite-polyamide 6 composites: HA/PA6 composites were prepared by the coordination and dissolution of complexing agents. Firstly, _CaCl2 and _{C2H5OH were} massaged in a closed dry container The ratio of 1:5 was mixed and stirred for 10 minutes, the temperature was set at 68-72 ° C, the content of hydroxyapatite (HA) was set at 40%, mixed with polyamide 6 (PA6), and then placed in the above container and stirred for 20 minutes , obtain the HA/PA6 composite material, then select the plasma reduction method to carry silver to the above-mentioned HA/PA6 composite material, set the silver content at 0.6% and mix with the HA/PA6 composite material, and then add 5-20% glass fiber to carry out Mix and stir, and finally dry the finished product and put it into a ball mill for processing to obtain an Ag/HA/PA6 composite material with a grain size of 80-100 nm; (f) The metal nano-mixture powder material and the silver-hydroxyapatite-polyamide 6 composite powder are fully mixed with a mass fraction ratio of 3:1, respectively, and the obtained powder is named as material 1, and the β-phosphoric acid triphosphate The calcium-polypyrrole-biotin powder is named as material 2, and the icariin-biotin-polylactic acid microsphere powder is named as material 3, so far the preparation work is completed; the simulated 3D model is imported into a 3D printer, and a selective laser is used Melting technology (Selective laser melting, SLM) uses material 1 to print spheroids with a diameter of 2-2.2cm on the auxiliary stent, as the "core" of the femoral head, the diameter of the nozzle is set to 120-150nm, and the printing speed is set to 80-100mm /min, the printed structure is set to a body-centered cubic porous structure, the pore size is set at 600-650μm, the porosity is set at 45%-55%, and the pillar diameter is designed at 1000-1200μm, and then use material 2 in the femoral "core" ” on the basis of the rotation and movement of the auxiliary support to continue printing 6-8mm thick, as the second layer, the nozzle diameter is set to 120-150nm, the printing speed is set to 80-100mm/min, and the body-centered cubic porous structure is used. For printing, the pore size is set at 600-650μm, the porosity is set at 45%-55%, and the pillar diameter is designed at 1000-1200μm, and then the SLM technology is used to print 1-1.2cm thick on the basis of material 1 and material 2, as The third layer, the nozzle diameter is set to 120-150nm, the printing speed is set to 80-100mm/min, the body-centered cubic porous structure is used for printing, the pore size is set to 600-650μm, and the porosity is set to 45%-55%. The diameter of the pillar is designed to be 1000-1200μm. During the printing process, an ultrasonic vibration horn is added, the vibration frequency is 80-100kHz, the amplitude is 20-150μm, and the tool head is 40-50mm away from the axis of the laser head. At this point, the semi-finished product of the femoral head is completed, and the semi-finished stock The bones were removed from the auxiliary support and placed in a centrifuge tube, the suspension of material 3 and 10% gelatin were added, centrifuged at low speed for 10 min, frozen for 24 h, and the femoral head was treated with balls; (g) Relieve the femoral head after the ball loading treatment, and then weigh hydroxyapatite (HA), β-tricalcium phosphate and CaB ₆ powder with an electronic balance at a ratio of 47:48:5, respectively, and put the The three powders were mixed thoroughly with a ball mill. The powder particle size of HA was 30 nm and the purity was 99.9%, the particle size of CaB ₆ powder was 45 nm, and the particle size of beta tricalcium phosphate powder was 30 nm and the purity was 99.8%. The binder is mixed and stirred for 5 minutes, and the above mixed powder is prepared into a paste with a certain viscosity and coated on the surface of the femoral head. The thickness of the pre-set layer of powder is 4-6 mm. After standing at room temperature for 24 hours, put it in a vacuum drying box After drying for 2 hours, the temperature of the vacuum drying oven was set to 45 °C, and the femoral head was combined with the paste by laser cladding. The argon flow rate is 40%, and the argon gas flow rate is 10L/min. The bioceramic coating is prepared. Finally, the molded product is polished to reduce the surface roughness of the material.

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