Preparation method of 3D printed metal and high molecular polyethylene integrated hip joint prosthesis

Abstract

The present invention relates to the field of medical equipment, specifically to a method for preparing a 3D printed metal and polymer polyethylene integrated hip joint prosthesis. Microcapsules are prepared with carbon nanotubes and dicyclopentadiene as core materials and urea-formaldehyde resin as wall materials, and are blended with mechanically activated polymer polyethylene materials, vitamin E and Grubbs second-generation catalysts to prepare polymer polyethylene materials with high mechanical strength and self-repairability, which can effectively resist wear and improve service life. The 3D printed metal surface trabecular structure is implanted into the human body through biological fixation, which expands the age range of the applicable population, and plays an anti-rotation and fixation function by designing columns, ridges or screw holes. The present invention optimizes the friction pair of the "gold to gold" surface replacement hip joint, avoiding adverse events such as ion poisoning caused by metal wear debris. Compared with traditional machining (subtractive manufacturing) processes, it saves raw materials and reduces production costs.

Description

Technical Field

[0001] The present invention relates to the technical field of medical equipment, and in particular to a method for preparing a 3D printed metal and high-molecular polyethylene integrated hip joint prosthesis. Background Art

[0002] In recent years, with the deepening of the aging problem at home and abroad, the proportion of the elderly population has increased rapidly, and bone and joint diseases have increased day by day. More and more patients need to undergo artificial joint replacement surgery. The existing artificial joint prosthesis materials on the market are mainly metal materials (cobalt-chromium alloy, titanium alloy, tantalum, etc.), polymer materials (polymer polyethylene, polyether ether ketone, etc.), and ceramic materials (aluminum oxide, zirconium oxide, etc.). Several materials form the following friction pairs, namely: metal-to-metal, metal-to-ceramic, metal-to-polymer, ceramic-to-ceramic, and ceramic-to-polymer.

[0003] Surface replacement hip joints can retain more of the patient's own bone mass. For patients with smaller hip bone defects, surface replacement becomes the best choice. Since the amount of osteotomy in surface replacement hip joints is very small and the thickness of the bone prosthesis is also very thin, among the traditional implant materials, only metal materials can meet the two characteristics of relatively less wear and strong hardness. Therefore, the friction pairs of surface replacement hip joints on the market are mainly metal-to-metal (CoCrMo to CoCrMo). However, in the clinical application of existing artificial joint materials, implant failures caused by poor friction and wear performance continue to occur. For example, the amount of metal-to-metal wear is relatively large, and the metal ions produced by the wear debris have ion toxicity, which is not conducive to human health; ultra-high molecular weight polyethylene materials have material properties such as resistance to low temperatures, chemical corrosion resistance, wear resistance, self-lubrication and high biocompatibility, but at the same time have material disadvantages such as low hardness, poor creep resistance and bending resistance, so it has not appeared in the material application of surface replacement hip joint prosthesis; ceramic materials have very beneficial wear resistance, but the risk of material brittle fracture, so it has not been applied to the design of surface replacement hip joint prosthesis. Therefore, there is a great need for a 3D printed metal and polymer polyethylene integrated surface replacement hip prosthesis. Summary of the invention

[0004] The purpose of the present invention is to provide a method for preparing a 3D printed metal and high-molecular polyethylene integrated hip joint prosthesis to solve the problems raised in the above-mentioned background technology.

[0005] In order to solve the above technical problems, the present invention provides the following technical solution: a method for preparing a 3D printed metal and polymer polyethylene integrated hip joint prosthesis, comprising the following steps:

[0006] Step 1: Place the hydroxyl-functionalized carbon nanotubes in an ethanol solution and ultrasonically disperse them for 30 minutes; add ammonia water at 70-80°C; then add vinyl trimethoxysilane in 6-7 times, each time interval is 15-20 minutes, to obtain a mixed solution A, react for 5 hours, centrifuge, wash with deionized water, and dry to obtain modified carbon nanotubes;

[0007] Step 2: Dispersing the modified carbon nanotubes in dicyclopentadiene; adding resorcinol and sodium dodecylbenzene sulfonate, and ultrasonically dispersing for 30 minutes to obtain a mixed solution B;

[0008] Step 3: dissolving urea in a formaldehyde aqueous solution, heating in a water bath at 60-75°C with continuous stirring, adding triethanolamine solution to adjust the pH value to 8-9, reacting for 1-1.5 hours to obtain a prepolymer; mixing the prepolymer and mixed solution B, stirring for 20-30 minutes, adjusting the pH to 3-4 with dilute sulfuric acid, heating to 55-65°C, reacting for 2-3 hours, filtering, washing, and drying to obtain microcapsules;

[0009] Step 4: Print the metal powder into a metal acetabular shell through 3D printing technology; mechanically activate the polyethylene powder and mix it evenly with Grubbs second-generation catalyst, vitamin E, and microcapsules, and compound it with the metal acetabular shell through injection molding and hot pressing processes, and then form a polyethylene joint surface through turning to obtain the 3D printed metal and high-molecular polyethylene integrated hip joint prosthesis.

[0010] Furthermore, in step 1, the contents of the components in the mixed solution A are, by weight, 1 to 2 parts of hydroxyl-functionalized carbon nanotubes, 20 to 25 parts of ethanol solution, 2 to 3 parts of ammonia water, and 3.6 to 4.2 parts of vinyltrimethoxysilane.

[0011] Furthermore, in step 2, the contents of the components in the mixed solution B are, by weight, 0.5 to 1 parts of modified carbon nanotubes, 100 parts of dicyclopentadiene, 1 to 2 parts of resorcinol, and 0.5 to 1 part of sodium dodecylbenzene sulfonate.

[0012] Furthermore, in step 3, the content of each component in the prepolymer is, by weight, 5 to 10 parts of urea and 10 to 20 parts of formaldehyde aqueous solution.

[0013] Furthermore, in step 3, the ratio of the prepolymer to the mixed solution B is 1:(1-1.2) by weight.

[0014] Furthermore, in step 4, the contents of the components are, by weight, 80 to 100 parts of mechanically activated polyethylene powder, 0.5 to 0.8 parts of Grubbs second generation catalyst, 0.8 to 2.3 parts of vitamin E, and 1 to 3 parts of microcapsules.

[0015] Furthermore, in step 4, the polyethylene powder is preferably a high molecular weight polyethylene powder.

[0016] Furthermore, in step 4, the outer diameter of the metal acetabular shell ranges from 25mm to 85mm; the thickness of the outer porous structure is 0.8mm to 8mm, and the porosity is 20% to 75%; the thickness of the solid structure is 0.3mm to 1.5mm; the thickness of the inner porous structure is 0.15mm to 3mm, and the porosity is 10% to 80%; the thickness of the polyethylene component is 1.5mm to 7mm, and the roughness Ra is 0 to 2μm.

[0017] Compared with the prior art, the beneficial effects achieved by the present invention are as follows: the present invention innovatively designs a 3D printed metal and polymer polyethylene integrated hip joint prosthesis, replaces the traditional surface replacement hip joint metal friction surface with polyethylene material, and the femoral head prosthesis used in combination can be metal or ceramic, which greatly improves the wear resistance of the surface hip, optimizes the friction pair of the surface replacement hip joint "gold to gold", and avoids adverse events such as ion poisoning caused by metal wear debris. Compared with the traditional machining (subtractive manufacturing) process, it saves raw materials and reduces production costs. Microcapsules are prepared with vinyl-modified carbon nanotubes and dicyclopentadiene as core materials and urea-formaldehyde resin as wall materials, and are blended with mechanically activated polymer polyethylene materials, vitamin E and Grubbs second-generation catalysts to prepare polymer polyethylene materials. Among them, carbon nanotubes can effectively improve the mechanical properties of polyethylene materials; when the polyethylene material is worn, the microcapsule wall material breaks, and dicyclopentadiene can not only self-polymerize after contacting the catalyst, but also combine with vinyl-modified carbon nanotubes, thereby repairing the damaged part, which is beneficial to the preservation and processing of polyethylene materials. In addition, 3D printed metal surface trabecular structures can be implanted into the human body through biological fixation, which expands the age range of applicable people; convex ridges (such as Figure 4 As shown), columns (as Figure 5 as shown) or screw holes (as shown Figure 6 As shown), it plays an effective anti-rotation and fixation function after being implanted into the human body. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0019] Figure 1 is a schematic diagram of a 3D printed metal acetabular shell in Example 1 of the present invention;

[0020] Figure 2 It is a schematic diagram of the structure of the blank sample of the UHMWPE after injection molding and the 3D printed metal acetabular cup shell in Example 1 of the present invention;

[0021] Figure 3 This is a schematic diagram of the structure of a 3D printed metal and high-molecular polyethylene integrated hip joint prosthesis in Example 1 of the present invention;

[0022] Figure 4 This is a schematic diagram of the ridge structure designed on the outer surface of the present invention;

[0023] Figure 5 This is a schematic diagram of the column structure designed on the outer surface of the present invention;

[0024] Figure 6 It is a schematic diagram of the threaded hole-column structure designed on the outer surface of the present invention.

[0025] Among them, 1 is the outer porous structure, 2 is the solid structure, 3 is the inner porous structure, and 4 is the polyethylene joint surface. DETAILED DESCRIPTION

[0026] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] The raw materials used in the present invention and their sources are as follows: hydroxyl-functionalized carbon nanotubes are from Xi'an Qiyue Biology, with a catalog number of Q-0000237; ethanol is from Aladdin, with a CAS number of 64-17-5; ammonia is from Taixing Yichu Chemical, with a CAS number of 1336-21-6; vinyl trimethoxysilane is from Jessica Chemical, with a CAS number of 2768-02-7; resorcinol is from McLean, with a CAS number of 108-46-3; sodium dodecylbenzene sulfonate is from Sinopharm, with a CAS number of 25155-30-0; urea is from Blue Asahi Fine Chemicals, CAS No. 57-13-6; formaldehyde comes from Aladdin, CAS No. 50-00-0; sulfuric acid comes from McLean, CAS No. 7664-93-9; polyethylene comes from Ticona, CAS No. 9002-88-4, item number GUR4150, molecular weight 9 million; Grubbs second-generation catalyst comes from Chemicore, CAS No. 246047-72-3; vitamin E comes from McLean, CAS No. 2074-53-5; titanium alloy powder comes from Arcam, model TC4.

[0028] Embodiment 1:

[0029] Step 1: 1 g of hydroxyl-functionalized carbon nanotubes was placed in 20 g of ethanol solution and ultrasonically dispersed for 30 min; 2 g of ammonia water was added at 70°C; then 3.6 g of vinyltrimethoxysilane was added in 6 times, each time with an interval of 15 min to obtain a mixed solution A, reacted for 5 h, centrifuged, washed with deionized water, and dried to obtain modified carbon nanotubes;

[0030] Step 2: Disperse 0.5 g of modified carbon nanotubes in 100 g of dicyclopentadiene; add 1 g of resorcinol and 0.5 g of sodium dodecylbenzene sulfonate, and disperse by ultrasonic for 30 min to obtain a mixed solution B;

[0031] Step 3: dissolve 5g of urea in 10g of formaldehyde aqueous solution, heat in a water bath at 60°C with continuous stirring, add triethanolamine solution to adjust the pH value to 8, and react for 1h to obtain a prepolymer; mix the prepolymer and mixed solution B in a mass ratio of 1:1, stir for 20min, adjust the pH to 3 with dilute sulfuric acid, heat to 55°C, react for 2h, filter, wash, and dry to obtain microcapsules;

[0032] Step 4: Use 3D printing technology to print titanium alloy powder into a metal acetabular shell (such as Figure 1 As shown), the outer diameter of the metal acetabular shell is 25mm; the thickness of the outer porous structure 1 is 0.8mm, and the porosity is 20%; the thickness of the solid structure 2 is 0.3mm; the thickness of the inner porous structure 3 is 0.15mm, and the porosity is 10%; the polyethylene is mechanically activated, 80kg of mechanically activated polyethylene powder, 0.5kg of Grubbs second-generation catalyst, 0.8kg of vitamin E, and 1kg of microcapsules are mixed evenly, and then compounded with the metal acetabular shell by injection molding and hot pressing processes (as shown Figure 2 As shown), and then the polyethylene joint surface 4 is formed by turning to obtain the 3D printed metal and polymer polyethylene integrated hip joint prosthesis (as shown Figure 3 The specific method of the hot pressing process is to heat to 180°C, maintain at 15MPa for 30min, anneal at 140°C and 20MPa for 15min, and cool; the thickness of the polyethylene joint surface is 1.5mm, and the roughness Ra=1μm.

[0033] Embodiment 2:

[0034] Step 1: 1.1 g of hydroxyl-functionalized carbon nanotubes were placed in 20.5 g of ethanol solution and ultrasonically dispersed for 30 min; 2.3 g of ammonia water was added at 72 °C; then 3.8 g of vinyltrimethoxysilane was added in 7 times, each time with an interval of 16 min to obtain a mixed solution A, reacted for 5 h, centrifuged, washed with deionized water, and dried to obtain modified carbon nanotubes;

[0035] Step 2: Disperse 0.7 g of modified carbon nanotubes in 100 g of dicyclopentadiene; add 1.25 g of resorcinol and 0.8 g of sodium dodecylbenzene sulfonate, and disperse by ultrasonic for 30 min to obtain a mixed solution B;

[0036] Step 3: dissolve 8g of urea in 12g of formaldehyde aqueous solution, heat in a water bath at 65°C with continuous stirring, add triethanolamine solution to adjust the pH value to 9, react for 1.5h to obtain a prepolymer; mix the prepolymer and mixed solution B at a mass ratio of 1:1.05, stir for 25min, adjust the pH to 4 with dilute sulfuric acid, heat to 60°C, react for 2.5h, filter, wash, and dry to obtain microcapsules;

[0037] Step 4: Use 3D printing technology to print titanium alloy powder into a metal acetabular shell, the outer diameter of the metal acetabular shell is 35mm; the thickness of the outer porous structure 1 is 2mm, and the porosity is 25%; the thickness of the solid structure 2 is 0.5mm; the thickness of the inner porous structure 3 is 0.55mm, and the porosity is 30%; the polyethylene is mechanically activated, 85kg of mechanically activated polyethylene powder, 0.7kg of Grubbs second-generation catalyst, 1.2kg of vitamin E, and 1.1kg of microcapsules are mixed evenly, and compounded with the metal acetabular shell through injection molding and hot pressing processes, and then turned to form a polyethylene joint surface 4, to obtain the 3D printed metal and polymer polyethylene integrated hip joint prosthesis. Among them, the specific method of the hot pressing process is the same as that of Example 1, the thickness of the polyethylene joint surface is 2.5mm, and the roughness Ra=1.2μm.

[0038] Embodiment 3:

[0039] Step 1: 1.25 g of hydroxyl-functionalized carbon nanotubes were placed in 22 g of ethanol solution and ultrasonically dispersed for 30 min; 2.3 g of ammonia water was added at 75 ° C; then 3.8 g of vinyltrimethoxysilane was added in 6 times, each time interval was 18 min, to obtain a mixed solution A, reacted for 5 h, centrifuged, washed with deionized water, and dried to obtain modified carbon nanotubes;

[0040] Step 2: Disperse 0.65 g of modified carbon nanotubes in 100 g of dicyclopentadiene; add 1.3 g of resorcinol and 0.7 g of sodium dodecylbenzene sulfonate, and disperse by ultrasonic for 30 min to obtain a mixed solution B;

[0041] Step 3: Dissolve 7g of urea in 12.5g of formaldehyde aqueous solution, heat in a water bath at 70°C with continuous stirring, add triethanolamine solution to adjust the pH value to 8, react for 1.3h to obtain a prepolymer; mix the prepolymer and mixed solution B at a mass ratio of 1:1.15, stir for 23min, adjust the pH to 4 with dilute sulfuric acid, heat to 60°C, react for 2.5h, filter, wash, and dry to obtain microcapsules;

[0042] Step 4: Use 3D printing technology to print the titanium alloy powder into a metal acetabular shell, the outer diameter of the metal acetabular shell is 38mm; the thickness of the outer porous structure 1 is 2.6mm, and the porosity is 45%; the thickness of the solid structure 2 is 0.5mm; the thickness of the inner porous structure 3 is 0.72mm, and the porosity is 35%; the polyethylene is mechanically activated, 90kg of mechanically activated polyethylene powder, 0.63kg of Grubbs second-generation catalyst, 1.27kg of vitamin E, and 2.1kg of microcapsules are mixed evenly, and compounded with the metal acetabular shell by injection molding and hot pressing process, and then turned to form a polyethylene joint surface 4, and the 3D printed metal and polymer polyethylene integrated hip joint prosthesis is obtained. Among them, the specific method of the hot pressing process is the same as that of Example 1, the thickness of the polyethylene joint surface is 2.5mm, and the roughness Ra=1.4μm.

[0043] Embodiment 4:

[0044] Step 1: 1.36 g of hydroxyl-functionalized carbon nanotubes were placed in 22.5 g of ethanol solution and ultrasonically dispersed for 30 min; 2.38 g of ammonia water was added at 74 ° C; then 3.85 g of vinyltrimethoxysilane was added in 7 times, each time interval was 18 min, to obtain a mixed solution A, reacted for 5 h, centrifuged, washed with deionized water, and dried to obtain modified carbon nanotubes;

[0045] Step 2: Disperse 0.8 g of modified carbon nanotubes in 100 g of dicyclopentadiene; add 1.6 g of resorcinol and 0.8 g of sodium dodecylbenzene sulfonate, and disperse by ultrasonic for 30 min to obtain a mixed solution B;

[0046] Step 3: dissolve 6 g of urea in 13 g of formaldehyde aqueous solution, heat in a water bath at 68°C with continuous stirring, add triethanolamine solution to adjust the pH value to 8.5, react for 1.2 hours to obtain a prepolymer; mix the prepolymer and mixed solution B at a mass ratio of 1:1.12, stir for 25 minutes, adjust the pH to 4 with dilute sulfuric acid, heat to 58°C, react for 2 hours, filter, wash, and dry to obtain microcapsules;

[0047] Step 4: Use 3D printing technology to print the metal acetabular shell from titanium alloy powder, the outer diameter of the metal acetabular shell is 40mm; the thickness of the outer porous structure 1 is 1.3mm, and the porosity is 55%; the thickness of the solid structure 2 is 0.7mm; the thickness of the inner porous structure 3 is 1mm, and the porosity is 40%; the polyethylene is mechanically activated, 92kg of mechanically activated polyethylene powder, 0.62kg of Grubbs second-generation catalyst, 0.93kg of vitamin E, and 1.8kg of microcapsules are mixed evenly, and compounded with the metal acetabular shell by injection molding and hot pressing process, and then turned to form a polyethylene joint surface 4, and the 3D printed metal and polymer polyethylene integrated hip joint prosthesis is obtained. Among them, the specific method of the hot pressing process is the same as that of Example 1, the thickness of the polyethylene joint surface is 3.4mm, and the roughness Ra=1.5μm.

[0048] Embodiment 5:

[0049] Step 1: 1.5 g of hydroxyl-functionalized carbon nanotubes were placed in 23 g of ethanol solution and ultrasonically dispersed for 30 min; 2.6 g of ammonia water was added at 75 ° C; then 3.9 g of vinyltrimethoxysilane was added in 6 times, each time interval was 18 min, to obtain a mixed solution A, reacted for 5 h, centrifuged, washed with deionized water, and dried to obtain modified carbon nanotubes;

[0050] Step 2: Disperse 0.8 g of modified carbon nanotubes in 100 g of dicyclopentadiene; add 1.65 g of resorcinol and 0.9 g of sodium dodecylbenzene sulfonate, and disperse by ultrasonic for 30 min to obtain a mixed solution B;

[0051] Step 3: Dissolve 8.3 g of urea in 16.4 g of formaldehyde aqueous solution, heat in a water bath at 70°C with continuous stirring, add triethanolamine solution to adjust the pH value to 9, react for 1.2 hours to obtain a prepolymer; mix the prepolymer and mixed solution B at a mass ratio of 1:1.17, stir for 27 minutes, adjust the pH to 3 with dilute sulfuric acid, heat to 60°C, react for 2.5 hours, filter, wash, and dry to obtain microcapsules;

[0052] Step 4: Use 3D printing technology to print the titanium alloy powder into a metal acetabular shell, the outer diameter of the metal acetabular shell is 70mm; the thickness of the outer porous structure 1 is 2mm, and the porosity is 55%; the thickness of the solid structure 2 is 0.8mm; the thickness of the inner porous structure 3 is 0.7mm, and the porosity is 65%; the polyethylene is mechanically activated, 93kg of mechanically activated polyethylene powder, 0.68kg of Grubbs second-generation catalyst, 1.6kg of vitamin E, and 2.4kg of microcapsules are mixed evenly, and compounded with the metal acetabular shell by injection molding and hot pressing processes, and then turned to form a polyethylene joint surface 4, to obtain the 3D printed metal and polymer polyethylene integrated hip joint prosthesis. Among them, the specific method of the hot pressing process is the same as that of Example 1, the thickness of the polyethylene joint surface is 4.8mm, and the roughness Ra=1.8μm.

[0053] Embodiment 6:

[0054] Step 1: 2 g of hydroxyl-functionalized carbon nanotubes were placed in 25 g of ethanol solution and ultrasonically dispersed for 30 min; 3 g of ammonia water was added at 80 ° C; then 4.2 g of vinyltrimethoxysilane was added in 7 times, each time with an interval of 20 min to obtain a mixed solution A, reacted for 5 h, centrifuged, washed with deionized water, and dried to obtain modified carbon nanotubes;

[0055] Step 2: Disperse 1 g of modified carbon nanotubes in 100 g of dicyclopentadiene; add 2 g of resorcinol and 1 g of sodium dodecylbenzene sulfonate, and disperse by ultrasonic for 30 min to obtain a mixed solution B;

[0056] Step 3: dissolve 10g of urea in 20g of formaldehyde aqueous solution, heat in a water bath at 75°C with continuous stirring, add triethanolamine solution to adjust the pH value to 9, react for 1.5h to obtain a prepolymer; mix the prepolymer and mixed solution B at a mass ratio of 1:1.2, stir for 30min, adjust the pH to 4 with dilute sulfuric acid, heat to 65°C, react for 3h, filter, wash, and dry to obtain microcapsules;

[0057] Step 4: Use 3D printing technology to print the metal acetabular shell from titanium alloy powder, the outer diameter of the metal acetabular shell is 85mm; the thickness of the outer porous structure 1 is 8mm, and the porosity is 75%; the thickness of the solid structure 2 is 1.5mm; the thickness of the inner porous structure 3 is 3mm, and the porosity is 80%; the polyethylene is mechanically activated, 100kg of mechanically activated polyethylene powder, 0.8kg of Grubbs second-generation catalyst, 2.3kg of vitamin E, and 3kg of microcapsules are mixed evenly, and compounded with the metal acetabular shell by injection molding and hot pressing process, and then turned to form a polyethylene joint surface 4, and the 3D printed metal and polymer polyethylene integrated hip joint prosthesis is obtained. Among them, the specific method of the hot pressing process is the same as that of Example 1, the thickness of the polyethylene joint surface is 7mm, and the roughness Ra=2μm.

[0058] Comparative Example 1:

[0059] The titanium alloy powder is printed into a metal acetabular shell by 3D printing technology, and the outer diameter of the metal acetabular shell is 25mm; the thickness of the outer porous structure 1 is 0.8mm, and the porosity is 20%; the thickness of the solid structure 2 is 0.3mm; the thickness of the inner porous structure 3 is 0.15mm, and the porosity is 10%; the polyethylene is mechanically activated, 80kg of mechanically activated polyethylene powder, 0.5kg of Grubbs second-generation catalyst, and 0.8kg of vitamin E are mixed evenly, and compounded with the metal acetabular shell by injection molding and hot pressing processes, and then turned to form a polyethylene joint surface 4, and the 3D printed metal and polymer polyethylene integrated hip joint prosthesis is obtained. Among them, the specific method of the hot pressing process is to heat to 180℃, keep at 15MPa for 30min, and then anneal at 140℃ and 20MPa for 15min, and cool; the thickness of the polyethylene joint surface is 1.5mm, and the roughness Ra=1μm.

[0060] Comparative Example 2:

[0061] Step 1: dissolve 8g of urea in 12g of formaldehyde aqueous solution, heat in a water bath at 65°C with continuous stirring, add triethanolamine solution to adjust the pH value to 9, react for 1.5h to obtain a prepolymer; mix the prepolymer and carbon nanotubes in a mass ratio of 1:1.05, stir for 25min, adjust the pH to 4 with dilute sulfuric acid, heat to 60°C, react for 2.5h, filter, wash, and dry to obtain microcapsules;

[0062] Step 2: Use 3D printing technology to print titanium alloy powder into a metal acetabular shell, the outer diameter of the metal acetabular shell is 35mm; the outer porous structure 1 is 2mm thick and has a porosity of 25%; the solid structure 2 is 0.5mm thick; the inner porous structure 3 is 0.55mm thick and has a porosity of 30%; the polyethylene is mechanically activated, 85kg of mechanically activated polyethylene powder, 0.7kg of Grubbs second-generation catalyst, 1.2kg of vitamin E, and 1.1kg of microcapsules are mixed evenly, and compounded with the metal acetabular shell through injection molding and hot pressing processes, and then turned to form a polyethylene joint surface 4, to obtain the 3D printed metal and polymer polyethylene integrated hip joint prosthesis. Among them, the specific method of the hot pressing process is the same as that of Example 1, the thickness of the polyethylene joint surface is 2.5mm, and the roughness Ra=1.2μm.

[0063] Comparative Example 3:

[0064] The titanium alloy powder is printed into a metal acetabular shell by 3D printing technology, and the outer diameter of the metal acetabular shell is 38mm; the thickness of the outer porous structure 1 is 2.6mm, and the porosity is 45%; the thickness of the solid structure 2 is 0.5mm; the thickness of the inner porous structure 3 is 0.72mm, and the porosity is 35%; the polyethylene is mechanically activated, 90kg of mechanically activated polyethylene powder, 0.63kg of Grubbs second-generation catalyst, 1.27kg of vitamin E, and 2.1kg of carbon nanotubes are mixed evenly, and compounded with the metal acetabular shell by injection molding and hot pressing processes, and then the polyethylene joint surface 4 is formed by turning to obtain the 3D printed metal and polymer polyethylene integrated hip joint prosthesis. Among them, the specific method of the hot pressing process is the same as that of Example 1, the thickness of the polyethylene joint surface is 2.5mm, and the roughness Ra=1.4μm.

[0065] Experiment: The following tests were performed on Examples 1 to 6 and Comparative Examples 1 to 3 respectively:

[0066] Tensile strength test: Jinan Aideno LD-5 universal tensile testing machine was used, with a tensile rate of 200 mm / min;

[0067] Bending strength test: According to ISO 178-2010, the test was carried out using Shimadzu AGS-X desktop precision universal testing machine at a test speed of 500mm / min;

[0068] Self-healing performance: Five scratches with a length of 5 mm and a width of 0.1 mm were made on the surface of the polyethylene material. The material was placed in an environment of 60°C for 30 minutes, and the scratch repair was observed.

[0069] Example Tensile strength / MPa Bending strength / MPa Self-healing capability Example 1 33.4 53.1 No obvious scratches Example 2 35.6 50.6 No obvious scratches Example 3 31.2 51.1 No obvious scratches Example 4 36.7 52.9 No obvious scratches Example 5 38.4 49.8 No obvious scratches Example 6 30.5 50.7 No obvious scratches Comparative Example 1 27.3 38.6 Scratches not repaired Comparative Example 2 32.6 40.7 There are a few scratches Comparative Example 3 28.1 34.2 Scratches not repaired

[0070] Conclusion: The data of Examples 1 to 6 show that the polyethylene prepared by the present invention can effectively replace the traditional metal friction surface of the surface replacement hip joint, and not only has good mechanical strength, but also the surface scratches can be self-repaired after heating treatment. Taking Comparative Example 1 as a reference, the data of Example 1 show that the microcapsules containing carbon nanotubes have good compatibility with polyethylene, and blending can improve the mechanical properties of polyethylene; the data of Example 2 show that the dicyclopentadiene in the microcapsules can not only self-react to generate polydicyclopentadiene under the action of the catalyst, but also react with vinylized graphene to repair the worn parts, so the repair efficiency is higher, while the self-repair effect of the microcapsules in Comparative Example 2 is relatively low, so the self-repair effect of some scratches is not good; taking Comparative Example 3 as a reference, the data of Example 3 show that after directly blending carbon nanotubes with polyethylene, inorganic matter will agglomerate, resulting in a decrease in material performance. The present invention optimizes the friction pair of the "gold to gold" surface replacement hip joint, avoiding adverse events such as ion poisoning caused by metal wear debris.

[0071] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0072] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for preparing a 3D printed metal and polymer polyethylene integrated hip joint prosthesis, comprising the following steps: Printing metal powder into a metal acetabular shell by 3D printing technology; mechanically activating polyethylene powder, and evenly mixing it with Grubbs second-generation catalyst, vitamin E, and microcapsules, compounding it with the metal acetabular shell by injection molding and hot pressing, and then forming a polyethylene joint surface (4) by turning, thereby obtaining the 3D printed metal and high-molecular polyethylene integrated hip joint prosthesis; The metal powder is any one of cobalt-chromium alloy powder, titanium alloy powder and tantalum powder; The metal acetabular shell comprises, from the inside to the outside, an outer porous structure (1), a solid structure (2), and an inner porous structure (3); The outer diameter of the metal acetabular shell ranges from 25mm to 85mm; the thickness of the outer porous structure ranges from 0.8mm to 8mm, and the porosity ranges from 20% to 75%; the thickness of the solid structure ranges from 0.3mm to 1.5mm; the thickness of the inner porous structure ranges from 0.15mm to 3mm, and the porosity ranges from 10% to 80%; The preparation method of the microcapsules specifically comprises the following steps: Step 1: put 1-2 parts of hydroxyl-functionalized carbon nanotubes into 20-25 parts of ethanol solution and ultrasonically disperse for 30 minutes, add 2-3 parts of ammonia water at 70-80°C; then add 3.6-4.2 parts of vinyltrimethoxysilane in 6-7 times, each time interval is 15-20 minutes, to obtain a mixed solution A, react for 5 hours, centrifuge, wash and dry to obtain modified carbon nanotubes; Step 2: Disperse 0.5-1 parts of modified carbon nanotubes in 100 parts of dicyclopentadiene; add 1-2 parts of resorcinol and 0.5-1 parts of sodium dodecylbenzene sulfonate, and disperse by ultrasonic for 30 minutes to obtain a mixed solution B; Step 3: Dissolve 5-10 parts of urea in 10-20 parts of formaldehyde aqueous solution, heat in a water bath with stirring, add triethanolamine solution to adjust the pH value to 8-9, and react to obtain a prepolymer; mix the prepolymer and mixed solution B in a weight ratio of 1: (1-1.2), adjust the pH to 3-4 with dilute sulfuric acid, heat to 55-65°C, react for 2-3 hours, filter, wash, and dry to obtain microcapsules.

2. The method for preparing a 3D printed metal and polymer polyethylene integrated hip joint prosthesis according to claim 1, characterized in that: The polyethylene joint surface has a thickness of 1.5 mm to 7 mm and a roughness Ra of 1 to 2 μm.

3. The method for preparing the 3D printed metal and polymer polyethylene integrated hip joint prosthesis according to claim 1, characterized in that: The specific method of the hot pressing process is: heating to 180° C., maintaining at 15 MPa for 30 min, then annealing at 140° C. and 20 MPa for 15 min, and cooling.

4. A 3D printed metal and polymer polyethylene integrated hip prosthesis prepared according to the preparation method according to any one of claims 1 to 3.

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