Preparation method of bird nest-like porous lattice structure and application thereof

Abstract

The application discloses a preparation method of a bird nest-imitating porous lattice structure. The porous lattice structure comprises a plurality of parallel cross-section lamellas, and the cross-section lamellas comprise a plurality of micro rods. The preparation method comprises the following steps: constructing the cross-section lamella of the porous lattice structure according to the geometric relation of the micro rods in the cross-section lamella; confirming the position of the starting micro rod of the adjacent cross-section lamella according to the starting micro rod of the constructed cross-section lamella; constructing the cross-section lamella according to the confirmed position of the starting micro rod and the geometric relation of the micro rods in the cross-section lamella; repeating the above steps to obtain the porous lattice structure through layer-by-layer stacking; and confirming the position according to the included angle and intersection point of the starting micro rods of the adjacent cross-section lamellas. The application further discloses application of the preparation method in preparation of medical implant materials. The porous lattice structure is constructed through layer-by-layer stacking according to the geometric relation of the micro rods in the plurality of cross-section lamellas and the geometric relation of the starting micro rods of the adjacent cross-section lamellas, so that the mechanical properties of the porous lattice structure are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of porous materials, in particular to a preparation method of a bird nest-like porous lattice structure and application thereof. BACKGROUND

[0002] Lattice structure, as a special structure form with periodic arrangement of units, has shown outstanding performance potential in mechanics, physics and chemistry. The regular geometric configuration of lattice structure enables the material to effectively disperse stress through the deformation and coordination of unit structures when subjected to force, thereby achieving higher specific strength and specific stiffness at relatively lower density. At the same time, the periodicity and designability of lattice structure provide a broad space for functional applications. By adjusting the shape, size and arrangement of lattice units, the physical properties such as thermal conductivity, electromagnetic shielding and acoustic characteristics of the material can be precisely controlled. With the rapid development of computer-aided design and advanced manufacturing technology, especially additive manufacturing technology, the complex design of lattice structure can be accurately realized, laying a solid foundation for its wide application in various fields.

[0003] In the field of medical technology, bone implants prepared by 3D printing not only can accurately correspond to the anatomical form of damaged bone in appearance, but also can construct fine and controllable microporous structures with a diameter of hundreds of microns. These microporous structures not only provide space for bone tissue to grow into the interior of the prosthesis, but also effectively avoid the stress shielding effect caused by high stiffness materials. Related studies have shown that the introduction of porous structure in 3D printed bone implants can significantly affect the mechanical properties of bone implants and the bone remodeling behavior after implantation.

[0004] According to the long-term stability criterion proposed by SUN et al., the reconstruction of the surrounding bone tissue affects the ingrowth of bone tissue into the porous structure and the stable bone support provided by the surrounding bone to the implant. According to Wolff's law, bone tissue has the ability to sense load changes and dynamically adjust bone resorption and bone formation, on the basis of which the functional adaptation theory is developed, which believes that there is a physiological balance between mechanical stimulation and bone tissue. Within a certain range of stimulation, the growth and resorption processes of bone are balanced, and greater than this range will cause bone mass to increase, and less than this range will cause bone loss. According to the relationship between the two, it is proposed that the designed porous bone implant can effectively transmit stress to the surrounding bone when bearing the physiological load of the human body, so that the mechanical stimulation of the surrounding bone is as much as possible within the range that can promote bone growth and remodeling, thereby ensuring that the prosthesis can obtain stable bone support. On the other hand, it has a micro-porous structure design suitable for bone tissue ingrowth, including parameters such as pore type, pore size, porosity and micro-rod diameter.(SUN, C, MENG, Z. J., WANG, L., et al. Development and challenges of additive manufacturing of personalized implants[J]. Chinese Journal of Medical Instruments, 2024, 48(03): 237-244). SUMMARY

[0005] In view of the above background art, the present application provides a preparation method of a bird nest-like porous lattice structure and its application in preparing medical implant materials.

[0006] To achieve the above object, the present application provides the following technical solutions.

[0007] In one aspect, the present application provides a preparation method of a bird nest-like porous lattice structure, which comprises a plurality of parallel cross-sectional layers, and each cross-sectional layer comprises a plurality of micro rods; the preparation method comprises the following steps:

[0008] (1) constructing a cross-sectional layer of the porous lattice structure according to the geometric relationship of the micro rods in the cross-sectional layer;

[0009] (2) confirming the position of the starting micro rod of the adjacent cross-sectional layer according to the starting micro rod of the constructed cross-sectional layer;

[0010] (3) constructing the cross-sectional layer according to the confirmed position of the starting micro rod and the geometric relationship of the micro rods in the cross-sectional layer;

[0011] repeating steps (2) and (3) to obtain the porous lattice structure by layer-by-layer stacking;

[0012] In step (2), the position of the starting micro rod of the adjacent cross-sectional layer is confirmed according to the included angle and intersection point of the starting micro rod of the cross-sectional layer and the starting micro rod of the adjacent cross-sectional layer.

[0013] In the technical solution of the present application, the bird nest-like porous lattice structure refers to a porous lattice structure imitating the structure of a bird nest, and the micro rods in each cross-sectional layer are staggered and arranged, similar to the woven shape of a bird nest structure. The micro rods of each layer of cross-sectional layers in the woven shape structure have different forming directions, so that the porous lattice structure has load capacity in each direction, and the micro rods can transmit torsional force to the outside according to the direction of the micro rods along the stacking direction of the cross-sectional layers, thereby improving the torsional resistance.

[0014] In the technical solution of the present application, the micro rods are straight-line micro rods, broken-line micro rods, curved-line micro rods, or any combination thereof.

[0015] In some specific embodiments, the geometric relationship of the micro rods in the cross-sectional layer is parallel.

[0016] Alternatively, the parallelism is equidistant parallelism or non-equidistant parallelism; in the technical solution of the present application, the interval variation relationship of the non-equidistant parallelism is not particularly limited.

[0017] Preferably, the parallelism is equidistant parallelism.

[0018] In some specific embodiments, the microrods within the cross-sectional sheet are geometrically intersecting;

[0019] Optionally, the intersection includes intersection at any point on the microrod and intersection on the extension line of the microrod;

[0020] Optionally, the intersecting microrods within the cross-sectional sheet intersect at the same point or different points;

[0021] Optionally, the included angles of the intersecting microrods within the cross-sectional sheet may be equal or unequal; in the technical solution of the present invention, the variation relationship of the included angles of the intersecting microrods within the cross-sectional sheet is not particularly limited;

[0022] Preferably, the angle between the intersecting microrods within the cross-sectional sheet changes functionally with the order of the angles.

[0023] In some specific embodiments, the diameters of the microrods within the cross-sectional sheet are equal or unequal; in the technical solution of the present invention, the relationship of the diameter variation of the microrods within the cross-sectional sheet is not particularly limited;

[0024] Preferably, the microrods within the cross-sectional sheet have equal diameters.

[0025] In the technical solution of the present invention, the included angle between the starting microrods of adjacent cross-sectional sheets is 0° to 180°;

[0026] Optionally, the included angles between the starting microrods of adjacent cross-sectional sheets may be the same or different;

[0027] Optionally, the angle between the starting microrods of the cross-sectional sheet is not particularly limited in its variation along the direction of the cross-sectional sheet stacking; it can exhibit a regular variation or a random variation without order.

[0028] Preferably, the included angle between the starting microrods of the cross-sectional sheet varies regularly along the direction of the stacking of the cross-sectional sheets;

[0029] Preferably, the angle between the starting microrods of the cross-sectional sheet varies functionally along the direction of the stacking of the cross-sectional sheets;

[0030] Preferably, the angle between the starting microrods of the cross-sectional sheet varies as a linear function along the direction of the stacking of the cross-sectional sheets;

[0031] In some specific implementations, the expression for the linear function relationship is β = kn + a; where n is the number of layers in the cross-section; β is the angle between the starting microrods of the nth layer and the (n+1)th layer; a is a degree measure, ranging from 0 to 180°; and k is a proportionality coefficient.

[0032] In the technical solution of the present invention, the thicknesses of the cross-sectional sheets are equal or unequal;

[0033] Optionally, the variation of the thickness of the cross-sectional sheet along the direction of the stacking of the cross-sectional sheets is not particularly limited; it can exhibit a regular variation or a random variation without order.

[0034] Optionally, the thickness of the cross-sectional sheet varies along the direction of the stacking of the cross-sectional sheets in a functional relationship, preferably a linear function relationship;

[0035] Preferably, the thickness of the cross-sectional sheets is equal.

[0036] In the technical solution of the present invention, the intersection of the starting microrods of adjacent cross-sectional sheets is located on the microrod or on the extension line of the microrod.

[0037] In the technical solution of the present invention, the hole shape formed by adjacent cross-sectional layers is a polygon or a polygon-like shape composed of curved line segments, such as: triangle, parallelogram, square, trapezoid, rhombus, irregular quadrilateral, irregular pentagon or irregular hexagon, etc.

[0038] In the technical solution of the present invention, the direction of the progressively stacked cross-sectional sheets coincides with or forms an acute angle with the normal axis of the initial cross-sectional sheet;

[0039] In the technical solution of the present invention, the porous lattice structure of the biomimetic bird's nest is obtained by additive manufacturing methods; the additive manufacturing methods include fused deposition modeling (FDM), laser stereolithography (SLS), stereolithography (SLA), and digital light processing (DLP).

[0040] On the other hand, the present invention provides the application of the above preparation method in the preparation of medical implant materials.

[0041] Optionally, the medical implant materials include artificial vertebral bodies, artificial joint patches, artificial joints, artificial bones, interbody fusion devices, osteotomy guides, external fixation frames, orthopedic implants, dental implants, devices for total or partial joint replacement or repair, trauma repair devices, fracture repair devices, or veterinary implants, etc.

[0042] Optionally, the medical implant material is selected from one or more of the following: polyaryletherketones (PEKK), calcium carbonate, calcium silicate, tricalcium phosphate, calcium citrate, hydroxyapatite, montmorillonite, lithium saponite, bioglass, titanium, titanium alloys, magnesium, magnesium alloys, tantalum-based metals, cobalt-based alloys, zirconium-niobium alloys, nylon, and ultra-high molecular weight polyethylene.

[0043] The porous lattice structure in this invention is constructed by layering the geometric relationships of microrods within multiple cross-sectional sheets and the geometric relationships of the initial microrods in adjacent cross-sectional sheets. Compared with the prior art, this invention has the following advantages:

[0044] 1. The porous lattice structure in this invention is formed by microrods in an angled, staggered manner to create a woven porous lattice structure resembling a bird's nest. Thus, when the porous lattice structure is subjected to axial torque, it can effectively transmit the torque to the outside through the cross-sectional layered microrods, greatly improving the torsional resistance of the porous lattice structure while providing effective mechanical stimulation for the formation of osteoblasts.

[0045] 2. The porous lattice structure in this invention is simple to form. The spacing, width, and angle of the microrods in the cross-sectional sheet layers, as well as the angle between the starting microrods of adjacent cross-sectional sheet layers, can be controlled by regular or random variations, thereby controlling the pore shape, pore size, porosity, and connectivity between the pores in the porous lattice structure. Therefore, this porous lattice structure has programmability in local sheet regions.

[0046] 3. The porous lattice structure in this invention is mostly supported by solid axial forces, providing excellent axial support performance and significantly reducing or preventing sedimentation in the porous areas of the implant. The axial pores in its cross-section are mostly polygonal or near-polygonal columnar through-holes, providing a large surface area that facilitates cell adhesion and provides channels for cell growth, nutrient exchange, and the excretion of metabolic waste. Attached Figure Description

[0047] The invention, its features, shape, and advantages will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings. All drawings are not intended to be to scale and are intended to illustrate the main points of the invention.

[0048] Figure 1 This is a schematic diagram illustrating the forming process of the porous lattice structure mimicking a bird's nest according to the present invention.

[0049] Figure 2 This is a schematic diagram of the cross-sectional sheet structure of different microrod structures of the present invention.

[0050] Figure 3 This is a schematic diagram of the structure of the artificial cone with a porous lattice structure that mimics a bird's nest in Embodiment 1 of the present invention.

[0051] Figure 4 for Figure 3 A top view and a schematic diagram of the porous lattice structure resembling a bird's nest.

[0052] Figure 5 This is a schematic diagram of the structure of the artificial cone with a porous lattice structure that mimics a bird's nest in Embodiment 2 of the present invention.

[0053] Figure 6 for Figure 5 A top view and a schematic diagram of the formation of a porous lattice structure resembling a bird's nest.

[0054] Figure 7 The image shows a front view and a partial magnified view of the artificial joint patch with a porous lattice structure resembling a bird's nest, prepared according to the present invention.

[0055] Figure 8 for Figure 7 A top view and a magnified view of a portion thereof. Detailed Implementation

[0056] The following embodiments are merely some, not all, of the embodiments of the present invention. Therefore, the detailed descriptions of the embodiments provided below are not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0057] In this invention, unless otherwise specified, all equipment and raw materials are commercially available or commonly used in the industry. The methods described in the following embodiments are conventional methods in the art, unless otherwise specified.

[0058] See Figure 1 This invention provides a method for preparing a porous lattice structure resembling a bird's nest. The porous lattice structure comprises multiple parallel cross-sectional sheets 2, each cross-sectional sheet 2 comprising multiple microrods 1. The preparation method includes the following steps:

[0059] (1) Construct a porous lattice structure based on the geometric relationship of the microrods in the cross-sectional sheet; as shown in the figure, construct the cross-sectional sheet based on the geometric relationship of the microrods in the nth cross-sectional sheet;

[0060] (2) Determine the position of the starting microrod of the adjacent cross-sectional sheet based on the starting microrod of the constructed cross-sectional sheet; as shown in the figure, determine the position of the starting microrod of the (n+1)th layer of the adjacent cross-sectional sheet based on the starting microrod of the nth layer of the cross-sectional sheet.

[0061] (3) Construct the cross-sectional layer according to the confirmed position of the starting microrod and the geometric relationship of the microrods in the cross-sectional layer; as shown in the figure, construct the (n+1)th layer according to the position of the starting microrod of the (n+1)th layer and the geometric relationship of the microrods in the (n+1)th layer cross-sectional layer.

[0062] Repeat steps (2) and (3) to build the (n+2)th layer by layer, and so on, to form a porous lattice structure through the microrods of adjacent cross-sectional sheets and the microrods within the cross-sectional sheets;

[0063] In step (2), the position of the starting microrod of the adjacent cross-sectional sheet is determined based on the angle and intersection of the starting microrod of the starting microrod of the cross-sectional sheet and the starting microrod of the adjacent cross-sectional sheet.

[0064] In one embodiment, the microrod can be a straight microrod, a polygonal microrod, a curved microrod, or any combination thereof; Figure 2 The diagram shows the structure of cross-sectional sheets constructed from linear microrods, polygonal microrods, and curved microrods, respectively.

[0065] In one embodiment, the microrods within the cross-sectional sheet are geometrically parallel; such as Figure 1 As shown in the AC diagram, d1 is the distance between the starting microrod and its adjacent microrods; d2 is the distance between the microrods adjacent to the starting microrod and their adjacent microrods, and so on.

[0066] Optionally, the microrods within the cross-sectional sheet are either equidistant parallel (i.e., d1 = d2 = ... = dn) or non-equidistant parallel (i.e., d1 ≠ d2 ≠ ... ≠ dn). Preferably, the microrods within the cross-sectional sheet are equidistant parallel, as this allows for uniform axial load-bearing capacity and the formation of a uniformly distributed pore network. This well-developed pore network provides connection pathways for bone cells and blood vessels, resulting in better mechanical properties and more ideal biocompatibility. Furthermore, the non-equidistant parallel spacing is not particularly restricted and can exhibit either regular or random variations.

[0067] In one embodiment, the microrods within the cross-sectional sheet are geometrically intersecting; such as Figure 1 The diagram shows d~i; in the diagram, α1 is the angle between the starting microrod and its adjacent microrod within the cross-sectional sheet; α2 is the angle between the adjacent microrod and its adjacent microrod within the cross-sectional sheet, and α3 and so on; β n β is the angle between the starting microrods of the nth cross-sectional sheet and the starting microrods of the (n+1)th cross-sectional sheet; n+1 Let P1 be the angle between the starting microrods of the (n+1)th and (n+2)th cross-sectional sheets, and so on; P1, P2, and P3 are the intersection points of the microrods within the cross-sectional sheets; P n '、P n+1 ' is the intersection of the starting microrods of adjacent cross-sectional sheets;

[0068] Optionally, the microrods within the cross-sectional sheet can intersect at any point on the microrod (e.g., Figure 1 In the diagrams g, h, i) and the lines intersecting the extensions of the microrods (e.g., ... Figure 1 On figures d, e, and f);

[0069] Optionally, the intersecting microrods within the cross-sectional sheet intersect at the same point (e.g., Figure 1 Figure d) or different points (e.g.) Figure 1 Figure e to i);

[0070] Optionally, the included angles of the intersecting microrods within the cross-sectional sheet may be equal or unequal; wherein, there are no particular restrictions on the variation of the included angles of the intersecting microrods within the cross-sectional sheet.

[0071] Preferably, the angle between intersecting microrods within the cross-sectional sheet changes in a functional relationship with the order of the angles, for example, a linear function. Controlling the angle between intersecting microrods within the cross-sectional sheet through this functional relationship facilitates parametric design according to different application scenarios. It allows control over the pore shape, pore size, porosity, and connectivity between pores through specific functional changes. In particular, the linear change of the linear function can give the porous lattice structure more uniform mechanical properties and good porosity.

[0072] In one embodiment, the diameters of the microrods within the cross-sectional sheet are equal or unequal; wherein, the relationship of diameter variation of the microrods within the cross-sectional sheet is not particularly limited, and can exhibit regular variation or random variation without order;

[0073] Preferably, the microrods within the cross-sectional lamellae have equal diameters; equal diameters enable more uniform mechanical properties of the porous lattice structure.

[0074] In one embodiment, the intersection of the starting microrods of adjacent cross-sectional sheets is located on the microrod (e.g., Figure 1 Figures b, c, e, h, i) or the extension of the microrod (e.g. Figure 3-4 Figure f in the middle.

[0075] In one embodiment, the included angle between the starting microrods of adjacent cross-sectional sheets is 0° to 180°;

[0076] Optionally, the included angles between the starting microrods of adjacent cross-sectional sheets may be the same or different;

[0077] Optionally, the angle between the starting microrods of the cross-sectional sheet is not particularly restricted in the direction of the cross-sectional sheet stacking; it can be a regular change or a random change.

[0078] Preferably, the included angle between the initial microrods of the cross-sectional sheet varies regularly along the direction of the stacking of the cross-sectional sheets;

[0079] Preferably, the angle between the initial microrods of the cross-sectional sheet varies functionally along the direction of the cross-sectional sheet stacking;

[0080] Preferably, the angle between the starting microrods of the cross-sectional sheet varies along the direction of the cross-sectional sheet stacking as a linear function; wherein, the expression of the linear function is β=kn+a; n is the number of cross-sectional sheets; β is the angle between the starting microrods of the nth and (n+1)th layers; a is a degree measure, ranging from 0 to 180°; and k is a proportionality coefficient.

[0081] In one embodiment, the thicknesses of the cross-sectional sheets are equal or unequal;

[0082] Optionally, the variation of the thickness of the cross-sectional sheets along the direction of stacking of the cross-sectional sheets is not particularly restricted; it can exhibit a regular variation or a random variation.

[0083] Optionally, the thickness of the cross-sectional sheet varies along the direction of the cross-sectional sheet stacking in a functional relationship, preferably a linear function relationship;

[0084] Preferably, the thickness of the cross-sectional lamellae is equal; the equal thickness of the cross-sectional lamellae can form uniformly distributed pores, so that the porous lattice structure has a good pore network, which can provide a good connection path for bone cells and blood vessels.

[0085] In one embodiment, the aperture formed by adjacent cross-sectional layers is a polygon or a polygon-like shape composed of curved line segments, such as: triangle, parallelogram, square, trapezoid, rhombus, irregular quadrilateral, irregular pentagon or irregular hexagon, etc.

[0086] In one embodiment, the direction in which the cross-sectional sheets are stacked one after another coincides with or forms an acute angle with the normal axis of the initial cross-sectional sheet;

[0087] In one embodiment, the porous lattice structure of the biomimetic bird's nest is obtained by an additive manufacturing method; the additive manufacturing method includes fused deposition modeling (FDM), stereolithography (SLS), stereolithography (SLA), and digital light processing (DLP).

[0088] The above preparation method can be used to prepare porous medical implant materials.

[0089] In one embodiment, medical implant materials include artificial vertebrae, artificial joint patches, artificial joints, artificial bones, interbody fusion devices, osteotomy guides, external fixation devices, orthopedic implants, dental implants, devices for total or partial joint replacement or repair, wound repair devices, fracture repair devices, or veterinary implants, etc.

[0090] In one embodiment, the medical implant material is selected from one or more of the following: polyaryletherketones (PEKK), calcium carbonate, calcium silicate, tricalcium phosphate, calcium citrate, hydroxyapatite, montmorillonite, lithium saponite, bioglass, titanium, titanium alloys, magnesium, magnesium alloys, tantalum-based metals, cobalt-based alloys, zirconium-niobium alloys, nylon, and ultra-high molecular weight polyethylene.

[0091] Example 1

[0092] like Figure 3 As shown, this embodiment obtained an artificial cone with a porous lattice structure resembling a bird's nest prepared by polyetherketoneketone (PEKK) through the above preparation method.

[0093] The artificial vertebral body mainly includes a main structure 10, a bird's nest-like porous lattice structure 20 located above / below the main structure, and a bone graft window 30 penetrating the main structure 10 and the bird's nest-like porous lattice structure 20; wherein, the main structure 10 is a columnar body, and its sides are connected curved surfaces and smooth planes, and the connection is made smooth by rounded corners.

[0094] The fabrication process of the porous lattice structure 20, which mimics the Bird's Nest stadium, is as follows:

[0095] Step 1: The starting microrod 21 and other microrods in the cross-sectional sheet are all straight microrods. The starting microrod 21 and other microrods in the cross-sectional sheet are equidistant and parallel (the spacing d can be set according to the specific application). The cross-sectional sheet 22 is constructed according to this parallel relationship. In this embodiment, the boundary of the cross-sectional sheet 22 is composed of circular curves and other closed curves, and the angle between it and the horizontal plane is 0°.

[0096] Step 2: The angle β between the starting microrod 21 of the cross-sectional sheet 22 and the starting microrod of its adjacent cross-sectional sheet. n The angle is 45°, and the intersection point is P. n Located on or on the extension line of the starting microrod 21; the geometric relationship between the starting microrod of the adjacent cross-sectional sheet and the remaining microrods in the adjacent cross-sectional sheet is the same as that of the cross-sectional sheet 22; the adjacent cross-sectional sheets of the cross-sectional sheet 22 are constructed according to the above geometric relationship;

[0097] Repeating the above steps layer by layer, the final porous lattice structure resembling the bird's nest is obtained. Figure 5-6 (In the image, 23 is a magnified view of a portion of it).

[0098] In this embodiment, the thickness of each cross-sectional layer is equal.

[0099] The porous lattice structure mimicking a bird's nest prepared in this embodiment has a woven structure in the axial direction, mimicking the structure of a bird's nest. When subjected to axial torque, it can transmit the torque to the outside through the starting microrods on each cross-sectional layer, giving it greater stiffness in the tangential direction. This improves the torsional resistance of the vertebral body, enhances the stability of axial rotation, significantly reduces the micromomentum of the vertebral body, and reduces the risk of displacement or even dislocation of the artificial vertebral body.

[0100] In this embodiment, the thickness of the bird's nest-inspired porous lattice structure 20 is not particularly limited and can be set conventionally as needed, generally ≤5mm. This thickness range can balance the mechanical properties and cell growth requirements.

[0101] In this embodiment, the polyether ketone ketone (PEKK) material has good biocompatibility and mechanical properties. Its elastic modulus is between that of cortical bone and cancellous bone, which can effectively avoid the "stress shielding" phenomenon and is conducive to the growth and fusion of bone tissue.

[0102] In this embodiment, the artificial vertebra is fabricated by integral molding using additive manufacturing technologies such as fused deposition modeling (FDM), stereolithography (SLS), stereolithography (SLA), or digital light processing (DLP), preferably fused deposition modeling (FDM) 3D printing integral molding technology.

[0103] Example 2

[0104] like Figure 7-8 As shown, this embodiment obtained an artificial cone with a bird's nest-like porous lattice structure prepared by polyether ketone ketone (PEKK) through the above preparation method.

[0105] The artificial vertebral body mainly includes a main structure 100, a bird's nest-like porous lattice structure 200 located above / below the main structure, and a bone graft window 300 penetrating the main structure 100 and the bird's nest-like porous lattice structure 200; wherein, the main structure 100 is a columnar body, and its sides are connected curved surfaces and smooth planes, and the connection is smoothed by rounded corners.

[0106] The fabrication process of the porous lattice structure 200, which mimics the Bird's Nest stadium, is as follows:

[0107] Step 1: The starting microrod 210 and other microrods within the first cross-sectional sheet are all straight microrods. The starting microrod 210 intersects with the other microrods within the cross-sectional sheet on their extended lines and intersects at the same point P1. The cross-sectional sheet 220 is constructed based on this relationship. In this embodiment, the included angle α of the microrods within the cross-sectional sheet 220 is 6°. The boundary of the first cross-sectional sheet is composed of circles and other closed curves. The included angle between the first cross-sectional sheet and the horizontal plane is 0°.

[0108] Step 2: The angle β1 between the starting microrod 210 of the first cross-sectional sheet and the starting microrod of the second cross-sectional sheet is 45°, and their intersection point P1' is located on the starting microrod of the second cross-sectional sheet; the geometric relationship between the starting microrod and the other microrods in the second cross-sectional sheet is: the angle is 6°, the intersection point is located on the extension line, and they intersect at different points; construct the second cross-sectional sheet according to the above geometric relationship;

[0109] The above steps were repeated layer by layer to prepare the final porous lattice structure 200 that resembles a bird's nest.

[0110] In this embodiment, the thickness of each cross-sectional layer is equal.

[0111] The porous lattice structure mimicking a bird's nest prepared in this embodiment has a woven structure in the axial direction, mimicking the structure of a bird's nest. When subjected to axial torque, it can transmit the torque to the outside through the starting microrods of each cross-sectional layer, giving it greater stiffness in the tangential direction. This improves the torsional resistance of the vertebral body, enhances the stability of axial rotation, significantly reduces the micromomentum of the vertebral body, and reduces the risk of displacement or even dislocation of the artificial vertebral body.

[0112] The above descriptions are merely two specific embodiments of the present invention and are not intended to limit the invention. The present invention can also be applied to other artificial implants, such as... ​ The radial prosthesis shown is an example of a prosthesis with a porous lattice structure. It is understood that the porous lattice structure of the radial prosthesis is formed by the same principle as the artificial vertebra in Example 1, through layer-by-layer stacking to form a porous lattice structure that mimics a bird's nest.

[0113] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing a porous lattice structure resembling a biomimetic bird's nest, characterized in that, The porous lattice structure comprises multiple parallel cross-sectional sheets, each cross-sectional sheet comprising multiple microrods; the fabrication method includes the following steps: (1) Construct the cross-sectional lattice structure of the porous lattice based on the geometric relationship of the microrods within the cross-sectional lamellae; (2) Based on the starting microrods of the constructed cross-sectional sheet, determine the positions of the starting microrods of the adjacent cross-sectional sheets; (3) Construct the cross-sectional sheet based on the confirmed position of the starting microrod and the geometric relationship of the microrods in the cross-sectional sheet; Repeat steps (2) and (3) to obtain the porous lattice structure by layer stacking; In step (2), the position of the starting microrod of the adjacent cross-sectional sheet is determined based on the angle and intersection of the starting microrod of the starting microrod of the cross-sectional sheet and the starting microrod of the adjacent cross-sectional sheet; The biomimetic bird nest porous lattice structure refers to a porous lattice structure that imitates the structure of a bird's nest, with microrods in each cross-sectional layer arranged in an interlaced manner, resembling the woven structure of a bird's nest. The geometric relationship of the microrods within the cross-sectional sheet is intersecting; The angle between the starting microrods of the cross-sectional sheet changes along the direction of the stacking of the cross-sectional sheets in a linear function relationship.

2. The preparation method according to claim 1, characterized in that, The microrod can be a straight microrod, a polygonal microrod, a curved microrod, or any combination thereof.

3. The preparation method according to claim 1, characterized in that, The intersection includes intersection at any point on the microrod and intersection on the extension line of the microrod.

4. The preparation method according to claim 3, characterized in that, The intersecting microrods within the cross-sectional sheet intersect at the same point or different points.

5. The preparation method according to claim 3, characterized in that, The included angles of the intersecting microrods within the cross-sectional sheet are equal or unequal.

6. The preparation method according to claim 3, characterized in that, The angle between intersecting microrods within the cross-sectional sheet varies functionally with the order of the angles.

7. The preparation method according to claim 1, characterized in that, The diameters of the microrods within the cross-sectional lamellae may be equal or unequal.

8. The preparation method according to claim 1, characterized in that, The included angle between the starting microrods of adjacent cross-sectional sheets is 0° to 180°.

9. The preparation method according to claim 8, characterized in that, The included angles between the starting microrods of adjacent cross-sectional sheet layers may be the same or different.

10. The preparation method according to claim 1, characterized in that, The thicknesses of the cross-sectional sheets may be equal or unequal.

11. The preparation method according to claim 1, characterized in that, The thickness of the cross-sectional sheet varies either regularly or randomly along the direction of the stacking of the cross-sectional sheets.

12. The preparation method according to claim 1, characterized in that, The thickness of the cross-sectional sheet varies functionally along the direction of the stacking of the cross-sectional sheets.

13. The preparation method according to claim 1, characterized in that, The thickness of the cross-sectional sheet varies along the direction of the stacking of the cross-sectional sheets as a linear function.

14. The preparation method according to claim 1, characterized in that, The intersection of the starting microrods of adjacent cross-sectional sheets is located on the microrod or on the extension line of the microrod.

15. The preparation method according to claim 1, characterized in that, The aperture formed by adjacent cross-sectional layers is a polygon or a polygon-like structure composed of curved line segments.

16. The preparation method according to claim 1, characterized in that, The direction in which the cross-sectional sheets are stacked one after another coincides with or forms an acute angle with the normal axis of the initial cross-sectional sheet.

17. The application of the preparation method according to any one of claims 1-16 in the preparation of medical implant materials.

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