A multi-structure reinforced personalized calcium phosphate ceramic structure, preparation method and application

Abstract

The present invention discloses a multi-structure reinforced personalized calcium phosphate ceramic structure, a preparation method and an application thereof, comprising a porous structure and a mechanical reinforcement structure for supporting and dispersing force; the porous structure comprises randomly distributed spherical holes and through holes generated by the intersection of the spherical holes; the mechanical reinforcement structure comprises string beams arranged in an array on the upper and lower surfaces of the ceramic structure, and web beams arranged on the sides of the ceramic structure for connecting the string beams; an oblique web beam is also arranged between the string beam and the web beam; the present invention enhances biological properties and mechanical strength through the porous structure and the mechanical reinforcement structure, reduces the risk of ceramic fracture, and the porous structure and the variable mechanical reinforcement structure give the restoration different properties, which can meet the requirements of the restoration for different defects of the skull and other components.

Description

Technical Field

[0001] The present invention relates to the technical field of medical material preparation, and in particular to a multi-structure reinforced personalized calcium phosphate ceramic structure, a preparation method and application thereof. Background Art

[0002] Calcium phosphate ceramic scaffolds are similar to natural bone components, have good biocompatibility and excellent osteoconductivity, and their specific phase composition and three-dimensional porous structure give calcium phosphate ceramic scaffolds good osteoinduction properties, so they are widely used in clinical bone defect repair. However, traditional porous calcium phosphate ceramic scaffolds generally have poor mechanical properties and are prone to fracture, which limits their clinical use to fill lacunar bone defects and cannot meet the mechanical requirements of segmental load-bearing bone repair. Therefore, the mechanical properties of calcium phosphate ceramics have always been an important factor limiting their widespread clinical application.

[0003] Porous structure is an important factor affecting the mechanical and biological properties of calcium phosphate ceramics, which mainly includes porosity, pore size, macropore geometry, interconnected pores and micropores. The macropore structure plays an important role in the biological properties of calcium phosphate ceramics. In order to achieve the growth of cells and tissues, as well as the transmission of nutrients, porous calcium phosphate ceramics still need to have interconnected macropores. However, the porous structure of ceramics obtained by traditional preparation methods is difficult to accurately control, which limits the improvement of their mechanical properties. In recent years, 3D printing technology has been widely used in the personalized preparation of biomaterials. It can not only realize the personalized construction of the appearance geometry of ceramics, but also realize the precise regulation of the internal pore structure of ceramics. It is an ideal method for preparing porous calcium phosphate ceramics.

[0004] In order to enhance the mechanical properties of porous ceramics, some researchers have begun to introduce reinforcement structures inside ceramics. These reinforcement structures are either metal stents or large-volume dense ceramics. The reinforcement structure has stronger compression and impact resistance than the porous ceramics themselves. After the introduction of the reinforcement structure, the overall mechanical properties of the stent will be improved to a certain extent. However, there are still some problems with the existing reinforcement structures. Porous ceramics with metal reinforcement structures cannot be completely degraded after implantation, and there is a long-term implantation risk. Large-volume dense ceramics are prone to stress shielding due to their uneven structure and spatial distribution and their equivalent elasticity is quite different from that of porous ceramics, which affects the mechanical properties of ceramics. The ideal reinforcement structure should have good biological activity and will not bring additional implantation risks; it should be evenly distributed inside the stent to protect the porous area from being damaged; it should have a reasonable structure, a certain porosity, and an equivalent elastic modulus close to that of porous ceramics, which will not cause stress shielding. This problem has not been fully solved in existing research.

[0005] Therefore, in order to expand the application of porous calcium phosphate ceramics in segmental load-bearing bone repair, how to use 3D printing technology to construct a suitable mechanical reinforcement structure inside the porous calcium phosphate ceramics to improve its mechanical strength without affecting its biological properties is a technical problem that needs to be solved urgently. Summary of the invention

[0006] In view of the problems existing in the prior art, the present invention provides a multi-structure reinforced personalized calcium phosphate ceramic structure, a preparation method and an application thereof, which organically combines the osteoinductive properties and mechanical properties of porous ceramics and satisfies the mechanical and biological requirements of bone repair in load-bearing parts for porous calcium phosphate ceramics.

[0007] The technical solution adopted by the present invention is:

[0008] A multi-structure reinforced personalized calcium phosphate ceramic structure, including a porous structure and a mechanical reinforcement structure for supporting and dispersing force; the porous structure includes randomly distributed spherical holes and through holes generated by the intersection of the spherical holes; the mechanical reinforcement structure includes string beams arranged in an array on the upper and lower surfaces of the ceramic structure, and a web beam arranged on the side of the ceramic structure for connecting the string beams; an oblique web beam is also arranged between the string beam and the web beam.

[0009] Furthermore, the chord beam includes a transverse beam arranged transversely and a vertical beam arranged vertically and intersecting the transverse beam.

[0010] Furthermore, the web beam connects the intersections of the corresponding positions of the transverse beams and the vertical beams on the upper and lower surfaces of the ceramic structure; the oblique web beam connects the intersection of the upper surface and the adjacent intersection closest to its corresponding intersection of the lower surface.

[0011] Furthermore, the spherical pores in the porous structure have a diameter of 300 μm to 800 μm, and a porosity of 40% to 70%.

[0012] A method for preparing a multi-structure reinforced personalized calcium phosphate ceramic structure, comprising the following steps:

[0013] Step 1: Construct a 3D model of the reconstructed bone defect and construct the contour of the restoration based on the 3D model;

[0014] For defects not on the midsagittal plane, the intact side is used as the reference by the mirror method to obtain the contour of the restoration that fits the defect; for defects on the midsagittal plane, the intact bone that is similar to the defect bone is matched, and the contour of the restoration that fits the defect is obtained after calculation;

[0015] Step 2: Construct a porous structure model; first construct a spherical hole, and generate N spherical holes that intersect with the spherical hole in random directions of the spherical hole; use the new spherical hole as the original spherical hole to generate a new spherical hole, and repeat until no new spherical holes that meet the constraint conditions can be generated in the target area;

[0016] Step 3: Combining the porous structure model and the restoration contour model obtained in step 1 to form a restoration model with a porous structure;

[0017] Step 4: Setting a mechanical reinforcement structure according to the surface curvature of the restoration model; combining the mechanical reinforcement structure with the restoration model with a porous structure to form a final model;

[0018] Step 5: Print the model generated in step 4 using 3D printing;

[0019] Step 6: The model printed in step 5 is sintered to obtain the desired multi-structure reinforced personalized calcium phosphate ceramic structure.

[0020] Furthermore, in the construction of the restoration contour in step 1, after obtaining the defect side structure by the mirroring method, a Boolean difference operation is performed between the intact side and the defect side to obtain a restoration contour that fits the defect; after matching the intact bone, a Boolean difference operation is performed between the intact bone and the defective bone to obtain a restoration contour that fits the defect.

[0021] Furthermore, the constraints in step 2 are: the porosity of the porous structure, and the preset pore sizes of the spherical pores and through holes.

[0022] Furthermore, the method for constructing the mechanical reinforcement structure in step 4 is as follows:

[0023] Vertical plates are set perpendicular to each other, and the upper and lower surfaces of the restoration model are stretched. The stretched upper and lower surfaces are subjected to Boolean intersection operation with the vertical plates to obtain the upper and lower surface string beams;

[0024] The string beam includes a transverse beam arranged transversely and a vertical beam arranged vertically and intersecting the transverse beam;

[0025] The web beam can be obtained by connecting the intersection points of the corresponding positions of the string beams on the upper and lower surfaces with a rectangular parallelepiped rod perpendicular to the string beam;

[0026] The oblique web beam is obtained by connecting the intersection point of the upper surface chord beam with the adjacent intersection point closest to the corresponding lower surface intersection point by an oblique rectangular parallelepiped rod.

[0027] Further, the sintering process is as follows:

[0028] First, dry the printed model;

[0029] Degreasing and sintering after drying:

[0030] Keep warm at 300℃~600℃ for 1~4h;

[0031] After debinding sintering, ceramic sintering is carried out:

[0032] Keep warm at 900℃~1200℃ for 1~4h.

[0033] An application of a multi-structure reinforced personalized calcium phosphate ceramic structure, and an application of the multi-structure reinforced personalized calcium phosphate ceramic structure in a bone repair device; the calcium phosphate ceramic is composed of a single phase, a two-phase or a combination of hydroxyapatite or tricalcium phosphate.

[0034] The beneficial effects of the present invention are:

[0035] (1) The present invention has a mechanical reinforcement structure, which can be set to a structure with different beam widths and different spacing combinations, giving the restoration different degrees of mechanical reinforcement performance;

[0036] (2) The present invention enhances biological properties and mechanical strength through porous structures and mechanical reinforcement structures, reduces the risk of ceramic fracture, and the porous structures and variable mechanical reinforcement structures give the prosthesis different properties, which can meet the requirements of the prosthesis for different defects of the skull and other parts;

[0037] (3) The porous structure of the present invention can ensure the permeability and retention rate of body fluids in the repaired body, thereby promoting the bone regeneration process. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 Schematic diagram of the structure of the skull repair body in an embodiment of the present invention.

[0039] Figure 2 It is a porous structure in the restoration of the present invention.

[0040] Figure 3 It is a mechanical reinforcement structure in the restoration of the present invention.

[0041] Figure 4 It is a schematic diagram of the structure of the restoration of the present invention.

[0042] Figure 5 It is a schematic diagram of the cross-sectional structure of the restoration of the present invention.

[0043] Figure 6 This is a graph of the alkaline phosphatase ALP activity expressed by cells after the multi-structure enhanced personalized calcium phosphate ceramics obtained in Example 2 of the present invention were co-cultured with bone marrow mesenchymal stem cells for 7 days.

[0044] In the figure: 1-porous structure, 2-mechanically reinforced structure. DETAILED DESCRIPTION

[0045] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0046] like Figure 1 to Figure 5As shown, a multi-structure reinforced personalized calcium phosphate ceramic structure includes a porous structure 1 and a mechanical reinforcement structure 2 for supporting and dispersing force; the porous structure 1 includes randomly distributed spherical holes and through holes generated by the intersection of the spherical holes; the mechanical reinforcement structure 2 includes string beams arranged in an array on the upper and lower surfaces of the ceramic structure, and a web beam arranged on the side of the ceramic structure for connecting the string beams; an oblique web beam is also arranged between the string beam and the web beam. The string beam includes a transverse beam arranged horizontally and a vertical beam arranged vertically intersecting the transverse beam. The web beam connects the intersections of the corresponding positions of the transverse beams and the vertical beams on the upper and lower surfaces of the ceramic structure; the oblique web beam connects the intersection of the upper surface and the adjacent intersection closest to the corresponding intersection of the lower surface. The spherical pores in the porous structure 1 have a pore size of 300μm to 800μm, and a porosity of 40% to 70%. Preferably, the spherical pores have a pore size uniformly distributed in the range of 600 to 800μm, and a porosity of 60%.

[0047] A method for preparing a multi-structure reinforced personalized calcium phosphate ceramic structure, comprising the following steps:

[0048] Step 1: Construct a 3D model of the reconstructed bone defect and construct the contour of the restoration based on the 3D model;

[0049] Mimics, VG Studio MAX, InVesalius and other software are used to reconstruct the 3D model of the bone defect based on the CT data of the target area, and the model is smoothed to facilitate subsequent processing. Mimics, VGStudio MAX, InVesalius and other software can also be used to construct the contour of the restoration.

[0050] For defects that are not on the midsagittal plane, the intact side is used as a reference by the mirroring method, and a Boolean difference operation is performed between the intact side and the defective side to obtain the contour of the restoration that fits the defect. For defects on the midsagittal plane, a complete bone similar to the defect bone is matched in the database, and a Boolean difference operation is performed between the complete bone and the defective bone to obtain the contour of the restoration that fits the defect after calculation.

[0051] Step 2: Construct a porous structure model;

[0052] Computer programming is used to generate an optimized foam-like ceramic structure in a selected spatial area. For example, Magics, Rhino, and Solidworks software can be used for construction.

[0053] First, a spherical hole is constructed at a random position in space, and N spherical holes intersecting with the spherical hole are generated in random directions of the spherical hole; the number and diameter of the generated new spherical holes are calculated based on the preset porosity. The degree of intersection between the generated new spherical holes and the original ones is determined by the set through hole diameter and spherical hole diameter. The new spherical hole is used as the original spherical hole to generate a new spherical hole, and the cycle is repeated until no new spherical holes that meet the constraints can be generated in the target area.

[0054] Step 3: Export the porous structure model to an STL file, and perform Boolean operation with the restoration contour model obtained in step 1 in the software to obtain a porous structure restoration model with excellent osteoinductive properties.

[0055] Step 4: Set the mechanical reinforcement structure according to the surface curvature of the restoration model; place vertical plates perpendicular to each other according to the required mechanical reinforcement structure parameters in modeling software such as Magics, Rhino, and Solidworks. The interval between the vertical plates is the side length of the mechanical reinforcement structure unit. The upper and lower surfaces of the restoration model are separated and stretched to give them a certain thickness. Perform Boolean intersection operations on the stretched upper and lower surfaces and the vertical plates to obtain the upper and lower surface chord beams;

[0056] The string beam includes a transverse beam arranged transversely and a vertical beam arranged vertically and intersecting the transverse beam;

[0057] The web beam can be obtained by connecting the intersection points of the corresponding positions of the string beams on the upper and lower surfaces with a rectangular parallelepiped rod perpendicular to the string beam;

[0058] The oblique web beam is obtained by connecting the intersection of the upper surface string beam with the adjacent intersection closest to the corresponding lower surface intersection with an oblique rectangular parallelepiped rod. The restoration model of the mechanical reinforcement structure and the porous structure is combined to form the final model;

[0059] Step 5: Output the model generated in step 4 as a print file, and import the print file into a 3D printer for printing. Printing can be done by any one or more of 3D printing technologies such as three-dimensional inkjet printing (3DP), selective laser sintering (SLS), stereo lithography (SLA), and digital light processing (DLP).

[0060] Step 6: The model printed in step 5 is sintered to obtain the desired multi-structure reinforced personalized calcium phosphate ceramic structure.

[0061] After printing, the model was placed in a beaker of anhydrous ethanol for ultrasonic cleaning. After cleaning, it was placed in an oven and dried at 60°C for at least 4 hours.

[0062] The sintering process is as follows:

[0063] First, dry the printed model;

[0064] Degreasing and sintering after drying:

[0065] Keep warm at 300℃~600℃ for 1~4h;

[0066] After debinding sintering, ceramic sintering is carried out:

[0067] Keep warm at 900℃~1200℃ for 1~4h.

[0068] Application of multi-structure enhanced personalized calcium phosphate ceramic structure in bone repair devices; calcium phosphate ceramic is composed of single phase, double phase or combination of hydroxyapatite or tricalcium phosphate.

[0069] The size and contour of the model are changed according to the size and contour of the patient's bone defect. The porous structure is designed with abundant pores to facilitate the transport of nutrients and metabolic waste. Compared with traditional foamed ceramics, the distribution of the pores in this structure is more uniform and reasonable, avoiding defects caused by the aggregation of pores; at the same time, the pores of this structure are connected with the existing pores during generation, avoiding the appearance of closed pores, improving the utilization rate of pores, and having a higher effective porosity. The mechanical performance enhancement structure adopts a structural design with triangular units, including a chord beam and a web beam. The chord beam and the web beam support each other to disperse the force.

[0070] The modeling software used in the following embodiments is Magics and Mimics. Other modeling software such as Rhino, VG Studio MAX, InVesalius, etc. can also be used.

[0071] Example 1

[0072] A multi-structure reinforced personalized calcium phosphate ceramic structure was constructed by following the steps below:

[0073] Step 1: Construct a 3D model of the reconstructed bone defect and construct the contour of the restoration based on the 3D model;

[0074] Step 2: Construct a porous structure model;

[0075] Step 3: Combining the porous structure model and the restoration contour model obtained in step 1 to form a restoration model with a porous structure;

[0076] Step 4: Setting a mechanical reinforcement structure according to the surface curvature of the restoration model; combining the mechanical reinforcement structure with the restoration model with a porous structure to form a final model;

[0077] Step 5: Import the print file into the light-curing printer and set the light source wavelength to 405nm and the light source power to 6.2mJ / cm 2 , the exposure time is 2s, and then the prepared ceramic slurry is used to start printing. After printing is completed, the model embryo is removed from the forming table.

[0078] Step 6: The obtained printed body is placed in a beaker filled with anhydrous ethanol, and then placed in an ultrasonic cleaner for 15 minutes. After ultrasonication 3 times, the body is taken out and placed in a 60°C oven for drying for 8 hours. The dried body is placed in a muffle furnace. In an air atmosphere, the furnace is heated from room temperature to 300°C at a heating rate of 2.5°C / min and kept warm for 2 hours; then heated to 550°C at a heating rate of 1°C / min and kept warm for 2 hours; then heated to 1000°C at a heating rate of 5°C / min and kept warm for 2 hours, and finally cooled with the furnace to obtain a calcium phosphate ceramic restoration.

[0079] The specific parameters are as follows: The calcium phosphate restoration used for the repair of beagle skull defects uses biphasic calcium phosphate (HA:β-TCP=3:7) calcium phosphate powder, and uses DLP printing technology to achieve ceramic forming. Its overall width is 30mm, the overall width is 30mm, the overall thickness is 3mm, and the porous structure is an optimized imitation foamed ceramic structure. The spherical hole diameter is 600μm, the through hole diameter is 200μm, the mechanical reinforcement structure width is 600μm, and the mechanical reinforcement structure interval is 3mm. The porous structure is used to enhance biological performance and promote tissue ingrowth. The mechanical reinforcement structure plays the role of load and dispersion force to ensure that the restoration is not damaged. The fixing holes are used to fix the restoration to the skull to prevent the restoration from shifting.

[0080] Example 2

[0081] A multi-structure reinforced personalized calcium phosphate ceramic structure was constructed by following the steps below:

[0082] Step 1: Construct a 3D model of the reconstructed bone defect and construct the contour of the restoration based on the 3D model;

[0083] Step 2: Construct a porous structure model;

[0084] Step 3: Combining the porous structure model and the restoration contour model obtained in step 1 to form a restoration model with a porous structure;

[0085] Step 4: Setting a mechanical reinforcement structure according to the surface curvature of the restoration model; combining the mechanical reinforcement structure with the restoration model with a porous structure to form a final model;

[0086] Step 5: Import the print file into the light-curing printer and set the light source wavelength to 405nm and the light source power to 6.2mJ / cm 2 , the exposure time is 2s, and then the prepared ceramic slurry is used to start printing. After printing is completed, the model embryo is removed from the forming table.

[0087] Step 6: The obtained printed body is placed in a beaker filled with anhydrous ethanol, and then placed in an ultrasonic cleaner for 15 minutes. After ultrasonication 3 times, the body is taken out and placed in a 60°C oven for drying for 8 hours. The dried body is placed in a muffle furnace. In an air atmosphere, the furnace is heated from room temperature to 300°C at a heating rate of 2.5°C / min and kept warm for 2 hours; then heated to 550°C at a heating rate of 1°C / min and kept warm for 2 hours; then heated to 1000°C at a heating rate of 5°C / min and kept warm for 2 hours, and finally cooled with the furnace to obtain a calcium phosphate ceramic restoration.

[0088] The specific parameters are as follows: The calcium phosphate restoration used for beagle dog back muscle implantation uses biphasic calcium phosphate (HA:β-TCP=3:7) calcium phosphate powder, and DLP printing technology is used to achieve ceramic forming. The model is a cylinder: the diameter is 12mm, the overall thickness is 3mm, the porous structure is an optimized imitation foamed ceramic structure, the spherical pore size is 600-800μm evenly distributed, the porosity is 60%, the through hole diameter is 250μm, the mechanical reinforcement structure width is 600μm, the mechanical reinforcement structure interval is 1.8mm, and the mechanical reinforcement structure is a single layer in the vertical direction. The porous structure is used to improve biological performance and promote tissue ingrowth, and the mechanical reinforcement structure plays the role of load and dispersion force to ensure that the restoration is not damaged.

[0089] Example 3

[0090] The process of this embodiment is the same as that of embodiment 1, except that the width of the mechanical reinforcement structure is 400 μm.

[0091] Example 4

[0092] The process of this embodiment is the same as that of embodiment 2, except that the thickness of the sample is 5.4 mm and it has two layers of mechanical reinforcement structure in the vertical direction.

[0093] Example 5

[0094] The process of this embodiment is the same as that of embodiment 1, except that the width of the mechanical reinforcement structure is 200 μm.

[0095] Example 6

[0096] The process of this embodiment is the same as that of embodiment 1, except that the interval of the mechanical reinforcement structure is 2 mm.

[0097] Example 7

[0098] The process of this embodiment is the same as that of embodiment 1, except that the width of the mechanical reinforcement structure is 1.5 mm.

[0099] Example 8

[0100] The process of this embodiment is the same as that of embodiment 1, except that the diameter of the spherical hole is 300 μm, and the diameter of the through hole is 150 μm.

[0101] Example 9

[0102] The process of this embodiment is the same as that of embodiment 1, except that the diameter of the spherical hole is 800 μm, and the diameter of the through hole is 350 μm.

[0103] Example 10

[0104] The process of this embodiment is the same as that of embodiment 1, except that the printing method is SLA.

[0105] Comparative Example 1

[0106] The process of this embodiment is the same as that of embodiment 2, except that there is no mechanical reinforcement structure.

[0107] Comparative Example 2

[0108] The process of this embodiment is the same as that of embodiment 1, except that the porous structure is a diamond structure.

[0109] The compressive strength test of the multi-structure reinforced personalized calcium phosphate ceramic structure obtained in the above embodiment was carried out in accordance with the provisions of GB / T 8489-2006. The results are shown in Table 1.

[0110] Table 1. Compressive strength of multi-structure reinforced personalized calcium phosphate ceramics

[0111]

[0112]

[0113] After co-culturing the bone-inducing calcium phosphate ceramics prepared in Example 2 with bone marrow mesenchymal stem cells for 7 days, the activity of alkaline phosphatase ALP expressed by the cells was tested. The results were as follows: Figure 6 As shown. It can be seen that the multi-structure enhanced personalized calcium phosphate ceramics prepared in Example 2 and the calcium phosphate ceramics without a reinforced structure in Comparative Example 1 both showed higher ALP activity, and were significantly higher than the blank group. Bone marrow mesenchymal stem cells (BMSCs) were provided by the Cell Bank of the Chinese Academy of Sciences Typical Culture Collection Committee (Shanghai, China).

[0114] Here’s how:

[0115] Bone marrow mesenchymal stem cells (BMSCs) were revived, passaged, and proliferated. BMSCs with good growth were inoculated on the multi-structure enhanced personalized calcium phosphate ceramics prepared in Example 2 (dry heat sterilization). After the materials and cells were co-cultured for 7 days, the cells were lysed and the ALP activity of the cells was measured using an alkaline phosphatase (ALP) kit.

[0116] from Figure 6 It can be seen that BMSCs in the multi-structure enhanced personalized calcium phosphate ceramics prepared in Example 2 and the calcium phosphate ceramics without reinforced structure in Comparative Example 1 both show higher ALP activity, and are significantly higher than the blank group. The test results show that the construction of the enhanced multi-structure provided by the present invention will not reduce the osteogenic activity of calcium phosphate ceramics.

[0117] The present invention imitates the porous structure of trabeculae in foamed ceramic / natural bone structure, designs a porous structure with high porosity and controllable pore structure to achieve good osteoinductive performance, and inserts a suitable mechanical reinforcement structure into the porous structure as the main load-bearing structure of the restoration, thereby achieving an organic combination of the osteoinductive performance and mechanical properties of the porous ceramic, while meeting the mechanical and biological requirements of porous calcium phosphate ceramics for bone repair in load-bearing areas.

Claims

1. A multi-structure reinforced personalized calcium phosphate ceramic structure, characterized in that: The invention comprises a porous structure (1) and a mechanical reinforcement structure (2) for supporting and dispersing force; the porous structure (1) comprises randomly distributed spherical holes and through holes generated by the intersection of the spherical holes; the mechanical reinforcement structure (2) comprises string beams arranged in an array on the upper and lower surfaces of the ceramic structure, and web beams arranged on the sides of the ceramic structure for connecting the string beams; an oblique web beam is also arranged between the string beam and the web beam; the string beam comprises a transverse beam arranged transversely and a vertical beam arranged vertically intersecting the transverse beam; the web beam connects the intersections of the transverse beams and the vertical beams on the upper and lower surfaces of the ceramic structure at corresponding positions; the oblique web beam connects the intersection of the upper surface with the adjacent intersection closest to the corresponding intersection of the lower surface.

2. A multi-structure reinforced personalized calcium phosphate ceramic structure according to claim 1, characterized in that: The spherical pores in the porous structure (1) have a diameter of 300 μm to 800 μm and a porosity of 40% to 70%.

3. A method for preparing a multi-structure reinforced personalized calcium phosphate ceramic structure as described in any one of claims 1 to 2, characterized in that: The following steps are involved: Step 1: Construct a 3D model of the reconstructed bone defect and construct the contour of the restoration based on the 3D model; For defects not on the midsagittal plane, the intact side is used as the reference by the mirror method to obtain the contour of the restoration that fits the defect; for defects on the midsagittal plane, the intact bone that is similar to the defect bone is matched, and the contour of the restoration that fits the defect is obtained after calculation; Step 2: Construct a porous structure model; first construct a spherical hole, and generate N spherical holes that intersect with the spherical hole in random directions of the spherical hole; use the new spherical hole as the original spherical hole to generate a new spherical hole, and repeat until no new spherical holes that meet the constraint conditions can be generated in the target area; Step 3: Combining the porous structure model and the restoration contour model obtained in step 1 to form a restoration model with a porous structure; Step 4: Set a mechanical reinforcement structure according to the surface curvature of the restoration model; combine the mechanical reinforcement structure with the restoration model with a porous structure to form the final model; the method for constructing the mechanical reinforcement structure is as follows: Vertical plates are set perpendicular to each other, and the upper and lower surfaces of the restoration model are stretched. The stretched upper and lower surfaces are subjected to Boolean intersection operation with the vertical plates to obtain the upper and lower surface string beams; The string beam includes a transverse beam arranged transversely and a vertical beam arranged vertically and intersecting the transverse beam; The web beam can be obtained by connecting the intersection points of the corresponding positions of the string beams on the upper and lower surfaces with a rectangular parallelepiped rod perpendicular to the string beam; The inclined web beam is obtained by connecting the intersection point of the upper surface chord beam with the adjacent intersection point closest to the corresponding lower surface intersection point by an inclined rectangular parallelepiped rod; Step 5: Print the model generated in step 4 using 3D printing; Step 6: The model printed in step 5 is sintered to obtain the desired multi-structure reinforced personalized calcium phosphate ceramic structure.

4. The method for preparing a multi-structure reinforced personalized calcium phosphate ceramic structure according to claim 3, characterized in that: In step 1, in the construction of the restoration contour, after obtaining the defect side structure by the mirroring method, a Boolean difference operation is performed between the intact side and the defect side to obtain a restoration contour that fits the defect; after matching the intact bone, a Boolean difference operation is performed between the intact bone and the defective bone to obtain a restoration contour that fits the defect.

5. The method for preparing a multi-structure reinforced personalized calcium phosphate ceramic structure according to claim 3, characterized in that: The constraints in step 2 are: the porosity of the porous structure, the preset pore sizes of the spherical pores and the through holes.

6. The method for preparing a multi-structure reinforced personalized calcium phosphate ceramic structure according to claim 3, characterized in that: The sintering process is as follows: First, dry the printed model; Degreasing and sintering after drying: Keep warm at 300℃~600℃ for 1~4h; After debinding sintering, ceramic sintering is carried out: Keep warm at 900℃~1200℃ for 1~4h.

7. Application of a multi-structure reinforced personalized calcium phosphate ceramic structure obtained by a preparation method according to any one of claims 3 to 6, characterized in that: Application of multi-structure enhanced personalized calcium phosphate ceramic structure in bone repair devices; calcium phosphate ceramic is composed of single phase, double phase or combination of hydroxyapatite or tricalcium phosphate.

Images