Interbody fusion device and its manufacturing method

Abstract

This invention provides an interbody fusion device, comprising multiple supports and multiple connectors for connecting the supports. The supports are arranged at intervals, and the connectors connect adjacent supports. Each support extends along the load-bearing direction, and its outer surface is concave to form a groove extending along the load-bearing direction. Each support has a pre-installed vascular channel network, including a main channel and multiple branch channels. The two ends of the main channel penetrate the upper and lower surfaces of the support along the load-bearing direction, respectively. One end of each branch channel communicates with the main channel, and the other end extends to the groove. This interbody fusion device can guide bone cells to grow directionally along the load-bearing direction and achieve immediate blood perfusion and comprehensive nutrient delivery upon implantation, solving the problems of insufficient deep nutrition, disordered bone ingrowth, and low fusion efficiency in traditional fusion devices.

Description

Technical Field

[0001] This invention relates to the field of medical device machinery, and more particularly to an intervertebral fusion device and its manufacturing method. Background Technology

[0002] Spinal interbody fusion is a classic and effective surgical procedure for treating degenerative spinal diseases such as lumbar disc herniation, lumbar spinal stenosis, spondylolisthesis, and spinal instability. Its core objective is to replace the supporting function of the diseased intervertebral disc by implanting an intervertebral fusion cage into the affected intervertebral space, inducing bony fusion between the upper and lower vertebral bodies, and ultimately restoring long-term spinal stability. In recent years, 3D-printed porous titanium alloy intervertebral fusion cages have gradually replaced traditional solid titanium alloy fusion cages and PEEK fusion cages, becoming the mainstream product in clinical applications due to their porosity highly matched to human cancellous bone, precisely controllable mechanical properties, and good biocompatibility. The core function of the porous structure of this type of fusion cage is to provide a physical support carrier for the adhesion, migration, proliferation, and differentiation of osteogenic functional cells such as bone marrow mesenchymal stem cells and osteoblasts, creating the necessary spatial conditions for bone tissue ingrowth into the fusion cage.

[0003] However, existing 3D-printed porous titanium alloy interbody fusion cages still suffer from two major technical deficiencies that urgently need to be addressed: First, current fusion cages generally employ a single-pore size, randomly distributed through-hole or semi-through-hole structure, lacking internal channels specifically designed for the directional transport of nutrients. The normal survival, proliferation, and maintenance of osteoblast activity of osteoblasts highly depend on a continuous and stable supply of nutrients such as oxygen, glucose, amino acids, and growth factors, while also requiring the timely removal of metabolic waste products. However, existing disordered porous structures rely solely on passive blood permeation for nutrient transport, with limited permeation distance and extremely low transport efficiency. This leads to decreased activity, delayed proliferation, and even apoptosis in cells within the deep regions of the fusion cage due to nutrient deficiency and accumulation of metabolic waste. This severely delays the osseointegration process between bone tissue and the fusion cage, prolongs the patient's postoperative recovery period, and significantly increases the risk of postoperative complications such as fusion cage loosening, displacement, and pseudoarthrosis.

[0004] Secondly, the existing multi-porous fusion device does not have a directional guiding structure on its surface and internal pores. The growth direction of osteoblasts on the surface and in the pores of the fusion device is completely random. A large number of osteoblasts diffusely grow laterally along the non-weight-bearing direction, while the effective bone ingrowth along the weight-bearing direction of the upper and lower vertebrae of the spine is insufficient. This results in low intervertebral fusion efficiency and insufficient fusion strength, making it difficult to form a stable bony connection in the early postoperative period and failing to meet the clinical needs of patients to get out of bed early.

[0005] In view of this, it is necessary to improve the existing interbody fusion devices to solve the above problems. Summary of the Invention

[0006] The purpose of this invention is to provide an interbody fusion device to solve the problem of low fusion efficiency caused by the random growth direction of osteoblasts in existing interbody fusion devices.

[0007] To achieve the above objectives, the present invention provides an interbody fusion device, which includes multiple support bodies and multiple connectors for connecting the support bodies. The multiple support bodies are arranged at intervals, and the connectors connect adjacent support bodies. The support bodies extend along the load-bearing direction, and the outer surface of the support body is recessed inward to form a groove extending along the load-bearing direction. Each support body has a pre-installed vascular channel network inside. The vascular channel network includes a main channel and multiple branch channels. The two ends of the main channel respectively penetrate the upper and lower surfaces of the support body along the load-bearing direction. One end of each branch channel communicates with the main channel, and the other end extends to the groove.

[0008] As a further improvement of the present invention, the diameter of the main channel is 0.5~1.2mm; the diameter of the branch channel is 100-300μm.

[0009] As a further improvement of the present invention, the outer surface of the support is also distributed with surface micropores for cell adhesion, the pore size of which is 50-150 μm.

[0010] As a further improvement of the present invention, the inner wall of the vascular channel network is provided with a biomodified layer, the biomodified layer comprising at least one of collagen, gelatin or fibronectin.

[0011] As a further improvement of the present invention, the biomodified layer is also loaded with sustained-release vascular endothelial growth factor and / or basic fibroblast growth factor.

[0012] As a further improvement of the present invention, artificial blood vessels are pre-cultured within the vascular channel network, and the artificial blood vessels are formed by endothelial cells spreading on the inner wall of the vascular channel network to form a continuous intima structure.

[0013] The present invention also provides a method for manufacturing an interbody fusion device, for manufacturing an interbody fusion device as described above, characterized by comprising the following steps:

[0014] S1: The support and connector are prepared using 3D printing technology. During the printing process, a through-type vascular channel network is pre-placed in the support. The vascular channel network includes a main channel and multi-level branch channels. S2: The inner wall of the vascular channel network is subjected to plasma treatment to improve hydrophilicity, and then coated with a biomodified layer; S3: Inject a high concentration of endothelial cell suspension into the main channel for seeding, and inject cells into the branch channels using negative pressure perfusion or centrifugation. S4: The inoculated support is placed in a bioreactor for dynamic perfusion culture to simulate blood flow shear force, so that endothelial cells form a continuous intima on the inner wall of the vascular channel network, thus completing the pre-culture of artificial blood vessels.

[0015] As a further improvement of the present invention, a finite element simulation step is included before step S1: based on the mechanical environment of the target intervertebral space, the diameter, distribution density and arrangement rules of the support are simulated and optimized to determine the printing parameters of the support and the connector.

[0016] As a further improvement of the present invention, in step S2, the biomodified layer includes at least one of collagen, gelatin or fibronectin, and the biomodified layer is loaded with sustained-release vascular endothelial growth factor and / or basic fibroblast growth factor.

[0017] As a further improvement of the present invention, in step S4, the flow rate of the dynamic perfusion culture is 0.1~1 mL / min, and the culture period is 7~14 days.

[0018] The beneficial effects of this invention are: the intervertebral fusion device of this invention, through the load-bearing skeleton structure of the support body and the connecting body, the groove along the load-bearing direction, and the main channel connecting the upper and lower endplates and the multi-level branch channels extending to the groove, can guide bone cells to grow in a directional manner along the load-bearing direction and realize immediate blood perfusion and full-area nutrient delivery upon implantation, thus solving the problems of insufficient deep nutrition, disordered bone ingrowth, and low fusion efficiency of traditional fusion devices. Attached Figure Description

[0019] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings: Figure 1 This is a schematic diagram of the interbody fusion device of the present invention; Figure 2 This is a schematic diagram of the structure of the support body of the intervertebral fusion device of the present invention; Figure 3 This is a flowchart of the manufacturing method of the intervertebral fusion device of the present invention.

[0020] Reference numerals: 100, interbody fusion device; 1, support body; 11, groove; 12, vascular access network; 121, main channel; 122, branch channel; 2, connector. Detailed Implementation

[0021] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0023] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances. Furthermore, the technical features involved in the different embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0024] like Figures 1 to 2 As shown, the present invention provides an interbody fusion device 100, which includes a plurality of support bodies 1 and a plurality of connectors 2 for connecting the support bodies 1. The plurality of support bodies 1 are arranged at intervals, and the connectors 2 connect adjacent support bodies 1.

[0025] The load-bearing direction is the height direction of the intervertebral fusion device 100, which can also be understood as the axial direction of the support body 1.

[0026] In this embodiment, the support 1 extends along the load-bearing direction, conforming to the physiological and mechanical transmission laws of the spine, and can provide stable and uniform mechanical support for the intervertebral space; the connector 2 ensures the integrity of the overall structure of the fusion device and its shear and torsional resistance. This structure avoids the problem of poor bioactivity of solid fusion devices and overcomes the defects of insufficient mechanical strength and easy settlement of fully porous fusion devices. At the same time, it reserves sufficient space for bone tissue ingrowth, which helps to reduce the stress shielding effect and improve the long-term stability of the fusion device.

[0027] The support 1 is columnar, which can be cylindrical, prismatic, or a column with a non-standard cross-section. Multiple connectors 2 are provided between two adjacent support 1s, and the connectors 2 are spaced apart along the load-bearing direction to achieve a better connection effect.

[0028] The support 1 extends along the load-bearing direction, and the outer surface of the support 1 is recessed inward to form a groove 11 extending along the load-bearing direction.

[0029] This invention provides a groove 11 extending along the load-bearing direction on the outer surface of the support 1. Utilizing the physical boundary constraint of the groove 11, it can actively guide osteogenic cells such as bone marrow mesenchymal stem cells and osteoblasts to climb, proliferate, and differentiate in a directional manner along the load-bearing direction of the upper and lower vertebrae of the spine. This effectively avoids the problem of transverse diffusion of bone cells along non-load-bearing directions in traditional porous fusion devices, significantly increasing the effective bone ingrowth along the load-bearing direction. This allows new bone tissue to form a bony bridge connecting the upper and lower vertebrae more quickly, establishing a stable bony connection in the early postoperative period, meeting the clinical needs of patients to get out of bed early, and significantly improving the final fusion strength.

[0030] Furthermore, in this embodiment, each support 1 is provided with four grooves 11, which are arranged in a circumferential array. The connecting body 2 is connected to the area of ​​the support 1 where no grooves 11 are provided.

[0031] Each of the support bodies 1 has a pre-installed vascular channel network 12, which includes a main channel 121 and multi-level branch channels 122. The two ends of the main channel 121 pass through the upper and lower surfaces of the support body 1 along the load-bearing direction, respectively. One end of the branch channel 122 is connected to the main channel 121, and the other end extends to the groove 11.

[0032] In this embodiment, a vascular channel network 12 composed of a main channel 121 and multi-level branch channels 122 is pre-formed inside the support body 1. The main channel 121 extends through the upper and lower surfaces of the support body 1 along the load-bearing direction at both ends. After implantation, it can directly contact the capillary blood seepage surfaces exposed after the upper and lower endplates are decored. There is no need to wait for passive blood infiltration. An active blood supply pathway from the endplate to the fusion device can be established immediately after implantation, providing osteoblasts with a continuous and stable supply of oxygen, glucose, amino acids and growth factors. At the same time, one end of the branch channel 122 is connected to the main channel 121 and the other end extends to the groove 11. It can accurately deliver blood and nutrients in the main channel 121 to the osteogenic active area on the surface of the support body 1 and timely remove waste products generated by cell metabolism. This fundamentally avoids the phenomenon of decreased activity, slow proliferation and even apoptosis of deep cells in the fusion device caused by the limited permeation distance of traditional disordered porous structures, and greatly accelerates the bone integration process between bone tissue and the fusion device. At the same time, the directed bone tissue will gradually wrap around and integrate the structures around the vascular channels, further consolidating the stability of the blood supply pathway and forming a virtuous cycle in which blood supply promotes osteogenesis and osteogenesis protects blood supply.

[0033] In some embodiments, the interbody fusion device 100 may also include a support structure without grooves 11 and / or vascular access network 12, which is used in combination with the support body 1 to improve the support strength. The support structure can be connected to the support body 1 through a connector 2.

[0034] The diameter of the main channel 121 is 0.5~1.2mm; the diameter of the branch channel 122 is 100-300μm. The main channel 121, as the main blood vessel, is responsible for rapidly receiving endplate blood leakage and transmitting it over long distances, while the branch channel 122, as a capillary network, is responsible for distributing nutrients to various osteogenic sites. The two work together to achieve efficient nutrient supply throughout the fusion device, fundamentally breaking through the bottleneck of nutrient delivery that traditional porous fusion devices rely on passive permeation, while also taking into account the mechanical support performance of the fusion device, providing dual protection for rapid and high-quality intervertebral fusion.

[0035] When the diameter of the main channel 121 is ≥0.5mm, it can effectively reduce blood flow resistance and ensure that the blood seeping from the endplate capillaries can be quickly and massively perfused into the fusion device, avoiding insufficient perfusion and blood stasis caused by the channel being too narrow. Before implantation of the interbody fusion device 100, the doctor will scrape off the surface cortex of the endplate, exposing a large number of capillaries. The opening of a single main channel 121 can cover the bleeding area of ​​thousands of capillaries on the endplate. Blood seeping from the capillaries naturally perfuses into the infiltrated vascular network, immediately establishing blood supply. Blood will enter the groove 11 through the vascular channel to deliver nutrients to the directionally growing osteoblasts, and the surface texture can induce directional differentiation of osteoblasts.

[0036] Conversely, if the diameter of the main channel 121 is less than 0.5 mm, the blood perfusion efficiency will drop sharply, failing to meet the nutritional needs of the deep cells inside the fusion device; if the diameter is greater than 1.2 mm, it will excessively weaken the axial load-bearing capacity of the support 1, damage the structural integrity of the support 1, and cause the fusion device to be prone to deformation, subsidence, or even breakage, increasing the risk of postoperative complications.

[0037] The diameter of 100-300μm ensures that blood is evenly distributed from the main channel 121 to each branch channel 122, and also allows for the rapid delivery of nutrients to the osteogenic active areas within the groove 11 through diffusion and osmosis, while simultaneously removing metabolic waste products from cells. Compared to the limitations of traditional disordered porous structures where nutrients can only passively permeate a few millimeters, this size of branch channel 122 can cover the entire surface of the support 1 with nutrient delivery, completely solving the problem of nutrient deficiency in the deep cells of the fusion vessel.

[0038] Conversely, if the diameter of branch channel 122 is less than 100 μm, the diffusion resistance of nutrients will increase dramatically, the transport efficiency will decrease significantly, and it will be easily blocked by cell debris or fibrin. If the diameter is greater than 300 μm, the blood flow velocity within branch channel 122 will slow down significantly, making it easier for thrombi to form and thus blocking the nutrient transport pathway. The range of 100-300 μm can maintain a suitable blood flow velocity, effectively reducing the risk of thrombosis and ensuring the long-term patency of the blood supply pathway.

[0039] The outlet of the branch channel 122 extends directly into the interior of the groove 11 along the load-bearing direction. The diameter of 100-300μm allows nutrients to form a uniform concentration gradient within the groove 11, providing continuous and stable nutritional support for osteoblasts that grow in the groove 11.

[0040] The outer surface of the support 1 is also distributed with surface micropores for cell adhesion, the pore size of which is 50-150 μm. This size range is most suitable for the adhesion, spreading and colonization of osteoblasts and bone marrow mesenchymal stem cells, which can significantly improve the cell adhesion efficiency and activity on the surface of the support 1, providing a stable cell adhesion basis for subsequent bone integration; at the same time, this pore size can ensure good cell affinity without weakening the surface structural strength of the support 1, and form a synergy with the vascular channel network 12 and directional grooves 11 to further accelerate bone ingrowth and fusion.

[0041] The inner wall of the vascular channel network 12 is provided with a biomodified layer, which includes at least one of collagen, gelatin, or fibronectin. The biomodified layer of collagen, gelatin, or fibronectin on the inner wall of the vascular channel network 12 can significantly enhance the hydrophilicity and cell adhesion of the channel inner wall, promote rapid adhesion, spread, and growth of endothelial cells, facilitate the formation of a continuous and complete artificial vascular intima, improve blood compatibility, reduce coagulation risk, and ensure long-term patency and efficient nutrient delivery of the vascular channel.

[0042] The biomodified layer is also loaded with sustained-release vascular endothelial growth factor (VEGF) and / or basic fibroblast growth factor (bFGF). VEGF primarily promotes endothelialization of vascular pathways and ensures unobstructed blood supply; bFGF has a dual function of promoting angiogenesis and osteosynthesis. The two can be loaded individually or in combination to simultaneously enhance vascularization and osteointegration, further accelerating intervertebral fusion.

[0043] The biomodified layer is loaded with sustained-release vascular endothelial growth factor and / or basic fibroblast growth factor, which can continuously induce endothelial cell proliferation and angiogenesis, accelerate the formation of artificial blood vessel intima and improve the long-term patency of the channel, while promoting osteoblast differentiation and bone tissue regeneration, thereby achieving simultaneous acceleration of blood supply reconstruction and bone integration, and further improving fusion efficiency.

[0044] Artificial blood vessels are pre-cultured within the vascular channel network 12. These artificial blood vessels are formed by endothelial cells spreading along the inner wall of the vascular channel network 12 to create a continuous intima structure. The artificial blood vessels pre-cultured within the vascular channel network 12, with their continuous intima formed by endothelial cells, can immediately connect with the endplate bleeding surface after implantation, enabling blood perfusion. This directly delivers nutrients and removes metabolic waste to the cells in the deep layers of the fusion device and the groove 11, preventing cell apoptosis due to insufficient nutrition. Simultaneously, the continuous intima enhances blood compatibility within the channel, reduces the risk of thrombosis, and ensures long-term patency of the blood supply pathway, fundamentally accelerating osseointegration and intervertebral fusion.

[0045] like Figure 3 As shown, the present invention also provides a method for manufacturing an interbody fusion cage 100, which includes the following steps: S1: The support body 1 and the connector body 2 are prepared using 3D printing technology. During the printing process, a through-type vascular channel network 12 is pre-set. The vascular channel network 12 includes a main channel 121 and a multi-level branch channel 122. Preferably, the vascular channel network 12 includes a main channel 121 with a diameter of 0.5~1.2mm and a multi-level branch channel 122 with a diameter of 100-300μm, while surface micropores with a diameter of 50-150μm are printed on the outer surface of the support 1.

[0046] Employing 3D printing integrated molding technology, the dimensional accuracy and spatial distribution of vascular channels and surface micropores can be precisely controlled, ensuring the consistency and repeatability of the product structure. The pre-installed gradient-sized channel network lays the structural foundation for subsequent artificial blood vessel cultivation and active nutrient delivery. The synchronously printed surface micropores provide a suitable microenvironment for osteoblast adhesion.

[0047] S2: The inner wall of the vascular channel network 12 is subjected to plasma treatment to improve hydrophilicity, and then a bio-modified layer is coated. The plasma treatment can effectively improve the hydrophobicity of the inner wall of the titanium alloy channel and improve the adhesion and uniformity of the bio-modified layer.

[0048] S3: Inject a high concentration of endothelial cell suspension into the main channel 121 for inoculation, and inoculate cells into the branch channel 122 using negative pressure perfusion or centrifugation; after inoculation, place the fusion vessel body in an incubator for static adherence culture for 2-4 hours to allow the endothelial cells to fully adhere to the inner wall of the channel.

[0049] Differentiated seeding methods were adopted to address the size differences between the main channel 121 and the branch channel 122: the main channel 121 has a larger space, and perfusion seeding can ensure uniform cell distribution; the branch channel 122 has a smaller diameter, and negative pressure perfusion or centrifugation seeding can overcome fluid resistance and allow cells to enter the deeper part of the channel smoothly; static adherent culture for 2-4 hours after seeding allows endothelial cells to fully adhere to the inner wall of the channel, avoiding the cells being washed away during subsequent dynamic perfusion, which significantly improves cell seeding efficiency and survival rate.

[0050] S4: The inoculated support 1 is placed in a bioreactor for dynamic perfusion culture, simulating blood flow shear forces. This allows endothelial cells to form a continuous intima on the inner wall of the vascular channel network 12, completing the pre-culture of the artificial blood vessel. Dynamic perfusion culture simulates the shear force environment of human physiological blood flow, inducing endothelial cells to align and form a continuous, complete functional intima structure, which cannot be achieved through static culture. Branch channels 122 obtain nutrients through diffusion and osmosis.

[0051] Before step S1, a finite element simulation step is included: based on the mechanical environment of the target intervertebral space, the diameter, distribution density, and arrangement rules of the support 1 are simulated and optimized to determine the printing parameters of the support 1 and the connector 2. By optimizing the parameters of the support 1 in advance through finite element simulation, the mechanical requirements of the target intervertebral space can be accurately matched before printing, balancing the bioactivity and mechanical support performance of the fusion device and avoiding the risk of mechanical failure later.

[0052] In step S2, the biomodified layer includes at least one of collagen, gelatin, or fibronectin, and is loaded with sustained-release vascular endothelial growth factor and / or basic fibroblast growth factor. Step S2, by coating the inner wall of the vascular channel network 12 with a biomodified layer containing at least one of collagen, gelatin, or fibronectin, and loading it with sustained-release vascular endothelial growth factor and / or basic fibroblast growth factor, enhances the hydrophilicity and cell adhesion of the channel inner wall, promoting rapid and uniform adhesion and spreading of endothelial cells. Furthermore, through the continuous sustained release of growth factors, it directionally induces endothelial cell proliferation and vascularization, while simultaneously promoting osteoblast differentiation and bone regeneration, significantly accelerating the formation of the artificial vascular intima, ensuring long-term patency of the channel, and achieving simultaneous and efficient advancement of blood supply reconstruction and bone integration.

[0053] In step S4, the flow rate of the dynamic perfusion culture is 0.1~1 mL / min, and the culture period is 7~14 days. The flow rate range of 0.1~1 mL / min provides suitable shear force without damaging endothelial cells; the culture period of 7~14 days ensures that the artificial blood vessel is fully mature and can immediately perform its blood transport function after implantation; the branch channel 122 obtains nutrients through diffusion and osmosis, which is adapted to its small diameter nutrient transport characteristics and ensures uniform growth of endothelial cells throughout the channel.

[0054] The interbody fusion device 100 of this invention, through the load-bearing skeleton structure of the support body 1 and the connecting body 2, the groove 11 along the load-bearing direction, and the main channel 121 connecting the upper and lower endplates and the multi-level branch channels 122 extending to the groove 11, can guide bone cells to grow in a directional manner along the load-bearing direction and achieve immediate blood perfusion and full-area nutrient delivery after implantation, solving the problems of insufficient deep nutrition, disordered bone ingrowth, and low fusion efficiency of traditional fusion devices. At the same time, the manufacturing method of 3D printing precision molding, plasma hydrophilic treatment, biological modification layer coating, differentiated cell seeding, and dynamic perfusion biomimetic culture can stably prepare the interbody fusion device 100 with continuous endothelial artificial blood vessels on the inner wall, significantly improving cell adhesion and vascularization efficiency, achieving immediate blood supply, rapid bone formation, and efficient fusion after implantation, greatly reducing the risk of postoperative loosening and displacement, and improving the stability and success rate of spinal fusion.

[0055] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0056] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. An interbody fusion device, characterized in that: The interbody fusion device includes multiple support bodies and multiple connectors for connecting the support bodies. The multiple support bodies are arranged at intervals, and the connectors connect adjacent support bodies. The support bodies extend along the load-bearing direction, and the outer surface of the support body is concave inward to form a groove extending along the load-bearing direction. Each support body has a pre-installed vascular channel network inside. The vascular channel network includes a main channel and multiple branch channels. The two ends of the main channel pass through the upper and lower surfaces of the support body along the load-bearing direction, respectively. One end of the branch channel is connected to the main channel, and the other end extends to the groove.

2. The interbody fusion device according to claim 1, characterized in that: The diameter of the main channel is 0.5~1.2mm; the diameter of the branch channel is 100-300μm.

3. The interbody fusion device according to claim 1, characterized in that: The outer surface of the support is also distributed with surface micropores for cell adhesion, and the pore size of the surface micropores is 50-150 μm.

4. The interbody fusion device according to claim 1, characterized in that: The inner wall of the vascular channel network is provided with a biomodified layer, which includes at least one of collagen, gelatin or fibronectin.

5. The interbody fusion device according to claim 4, characterized in that: The biomodified layer is also loaded with sustained-release vascular endothelial growth factor and / or basic fibroblast growth factor.

6. The interbody fusion device according to claim 1, characterized in that: Artificial blood vessels are pre-cultured within the vascular channel network, and the artificial blood vessels are formed by endothelial cells spreading on the inner wall of the vascular channel network to form a continuous intima structure.

7. A method for manufacturing an interbody fusion cage, for manufacturing an interbody fusion cage as described in any one of claims 1-6, characterized in that: Includes the following steps: S1: The support and connector are prepared using 3D printing technology. During the printing process, a through-type vascular channel network is pre-placed in the support. The vascular channel network includes a main channel and multi-level branch channels. S2: The inner wall of the vascular channel network is subjected to plasma treatment to improve hydrophilicity, and then coated with a biomodified layer; S3: Inject a high concentration of endothelial cell suspension into the main channel for seeding, and inject cells into the branch channels using negative pressure perfusion or centrifugation. S4: The inoculated support is placed in a bioreactor for dynamic perfusion culture to simulate blood flow shear force, so that endothelial cells form a continuous intima on the inner wall of the vascular channel network, thus completing the pre-culture of artificial blood vessels.

8. The method for manufacturing an interbody fusion device according to claim 7, characterized in that: Before step S1, there is also a finite element simulation step: based on the mechanical environment of the target intervertebral space, the diameter, distribution density and arrangement rules of the support are simulated and optimized to determine the printing parameters of the support and the connector.

9. The method for manufacturing an interbody fusion device according to claim 7, characterized in that: In step S2, the biomodified layer includes at least one of collagen, gelatin or fibronectin, and the biomodified layer is loaded with sustained-release vascular endothelial growth factor and / or basic fibroblast growth factor.

10. The method for manufacturing an interbody fusion device according to claim 7, characterized in that: In step S4, the flow rate of the dynamic perfusion culture is 0.1~1 mL / min, and the culture period is 7~14 days.

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