A magnetic field assisted extrusion type bio 3D printing device and method

Abstract

The application relates to a magnetic field auxiliary extrusion type biological 3D printing device and a working method, which comprises an extrusion system arranged vertically along an axis, the extrusion system is provided with a biological ink cartridge, the bottom end of the biological ink cartridge is connected with a nozzle, the biological ink cartridge is further connected with a gas pressure mechanism, a workpiece table is arranged below the extrusion system, characterized in that the biological ink cartridge is used for containing biological ink containing magnetic materials, a support table is arranged in a workpiece forming area of the workbench, an electromagnetic coil is arranged in the support table, the electromagnetic coil is connected with a control system through a magnetic field controller to exert vertical magnetic field force on the biological ink in the extrusion system, and the printing device of the application avoids the blockage of the nozzle and guarantees the smooth printing.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of biological additive manufacturing, in particular to a magnetic field assisted extrusion type biological 3D printing device and method. BACKGROUND

[0002] The statements herein are provided only to further provide context of the present application and are not necessarily prior art.

[0003] In the field of biological additive manufacturing, 3D printing technology has brought revolutionary changes to tissue engineering and personalized medicine. It can accurately construct complex biological structures from biological materials and cells according to a pre-set three-dimensional model, providing a highly potential solution for tissue repair, organ transplantation, etc. Extrusion type biological 3D printing is the most widely used method, which forms the target structure by extruding biological ink from the nozzle and stacking layer by layer.

[0004] In the manufacturing of biological structures, the demand for extremely small diameter structures is increasingly prominent. For example, microvascular networks are essential for maintaining the metabolism and function of tissues, and the fine structure of nerve fibers is indispensable for nerve signal transmission. However, there are many difficulties in manufacturing using extremely small diameters.

[0005] The extremely small diameter nozzle is prone to clogging during printing. On the one hand, the internal space of the extremely small diameter nozzle is extremely limited. Biological ink is a complex multiphase system containing cells, biopolymers and other functional components. When passing through the extremely small diameter nozzle, due to the narrow space, the cells in the biological ink are prone to aggregation, forming larger aggregates. At the same time, the viscosity characteristics of the biopolymer are amplified in this confined space, and the flowability is poor, more prone to gel-like substances. These factors combined, greatly increase the flow resistance of the biological ink in the nozzle, ultimately leading to nozzle clogging.

[0006] On the other hand, from the perspective of fluid mechanics, the flow of biological ink in the extremely small diameter nozzle is in a low Reynolds number state, with poor flow stability. In this case, the flow of ink is extremely sensitive to small disturbances, and local flow unevenness and pressure fluctuations can easily occur. This unstable flow state can cause the particulate components in the biological ink to precipitate and aggregate, thereby causing nozzle clogging, which seriously hinders the smooth progress of biological 3D printing at extremely small diameters. SUMMARY

[0007] In view of the deficiencies in the prior art, the present application aims to provide a magnetic field assisted extrusion type biological 3D printing device and method, which overcomes the clogging problem of the extremely small diameter nozzle during biological 3D printing.

[0008] In order to achieve the above-mentioned purpose, the present application is realized by the following technical scheme:

[0009] In a first aspect, embodiments of the present application provide a magnetic field assisted extrusion type biological 3D printing device, comprising an extrusion system vertically arranged along an axis, the extrusion system having a biological ink cartridge, a bottom end of the biological ink cartridge being connected to a nozzle, the biological ink cartridge further being connected to a gas pressure mechanism, a workpiece table being arranged below the extrusion system, the biological ink cartridge containing biological ink containing magnetic material, a support table being arranged in a workpiece forming area of the workpiece table, the support table having an electromagnetic coil arranged therein, the electromagnetic coil being connected to a control system through a magnetic field controller to apply a vertical magnetic field force to the biological ink in the extrusion system.

[0010] Optionally, the support table has a plurality of electromagnetic coils arranged in a closed loop.

[0011] Optionally, an inner side of the support table has a plurality of magnetic field strength sensors arranged in a ring shape, the magnetic field strength sensors being connected to the control system.

[0012] Optionally, an outer periphery of the biological ink cartridge has a first heating element connected to the control system, the first heating element being configured to heat the biological ink in the biological ink cartridge.

[0013] Further, the heating element is an electric resistance heating block.

[0014] Optionally, the support table has a second heating element arranged therein, and the support table has a temperature sensor arranged therein, the second heating element and the temperature sensor being connected to the control system to control the temperature of the support table.

[0015] Further, the second heating element is an electric resistance heating block arranged in the support table.

[0016] In a second aspect, embodiments of the present application provide a working method of the magnetic field assisted extrusion type 3D printing device of the first aspect.

[0017] The extrusion system moves according to a preset path in the control system, the extrusion system works, the biological ink containing magnetic material in the biological ink cartridge is extruded by the gas pressure, and is sprayed onto the support table by the nozzle to form a workpiece, during the forming process, the electromagnetic coil in the support table generates a magnetic field after being powered on, the magnetic field applies a vertical magnetic field force to the biological ink containing magnetic material to change the rheological properties of the biological ink.

[0018] Optionally, the electromagnetic coil applies a magnetic field strength ranging from 0.2T to 0.6T.

[0019] Optionally, the gas pressure for extruding the biological ink ranges from 15MPa to 50MPa.

[0020] Optionally, the first heating element is arranged on the outer periphery of the bio-ink cartridge, and the first heating element controls the temperature of the bio-ink in the bio-ink cartridge to be 15-35℃.

[0021] Optionally, the magnetic material in the bio-ink is a magnetic particle material or a magnetic fiber material.

[0022] The beneficial effects of the present application are as follows:

[0023] 1. The magnetic field assisted extrusion type bio-3D printing device of the present application is provided with an electromagnetic coil in the support table, and the bio-ink in the bio-ink cartridge contains a magnetic material, the electromagnetic coil can generate a magnetic field to exert a vertical magnetic field force on the bio-ink, change the rheological properties of the bio-ink, avoid nozzle clogging, uneven ink extrusion and other problems, make the shape of the ink at the nozzle outlet more regular, effectively control the flow and extrusion of the bio-ink in the extremely small diameter nozzle, and provide the possibility for manufacturing fine biological structures, break through the bottleneck of extremely small size that cannot be achieved due to nozzle clogging and other problems in the past, and the electromagnetic coil is arranged in the support table, compared with being arranged in the nozzle, the defect that the heat generated by the energization of the electromagnetic coil affects the gelation state of the bio-ink in the bio-ink cartridge is avoided, and the electromagnetic coil arranged in the workbench can realize the distribution of the electromagnetic coil in a larger range, if the magnetic material is a magnetic fiber, directional arrangement of the magnetic fiber in the workpiece can also be realized at the same time of exerting the magnetic field force, promote the directional growth of cells, and improve the performance of the workpiece.

[0024] 2. The magnetic field assisted extrusion type bio-3D printing device of the present application is provided with a first heating element in the bio-ink cartridge and a second heating element in the support table, the first heating element can accurately heat the bio-ink in the bio-ink cartridge according to the composition and rheological properties of different bio-inks. By adjusting the heating temperature, the viscosity, flowability and other key rheological parameters of the bio-ink can be accurately changed, so that the bio-ink can be in the best extrudable state before entering the nozzle, and the second heating element can be dynamically adjusted according to the solidification requirements of different biological materials, to provide suitable environmental conditions for the stable formation of the biological structure in the printing process.

[0025] 3. The magnetic field assisted extrusion type bio-3D printing device of the present application is provided with a magnetic field strength sensor, under the coordination of the control system, the magnetic field strength, nozzle moving speed and ink extrusion speed can be dynamically adjusted according to the model requirements, the magnetic field guides the deposition direction of the ink, and the support table can adjust the temperature through the second heating element to ensure the stability and biocompatibility, and high-precision printing is realized. BRIEF DESCRIPTION OF DRAWINGS

[0026] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0027] Figure 1 This is a schematic diagram of the overall structure of Embodiment 1 of the present invention;

[0028] Figure 2 This is a schematic diagram of the electromagnetic coil distribution in Embodiment 1 of the present invention;

[0029] Figure 3 This is a flowchart of the method in Embodiment 2 of the present invention;

[0030] Among them, 1. workpiece stage, 2. extrusion system, 3. air pipe, 4. support platform, and 5. electromagnetic coil. Detailed Implementation

[0031] Example 1

[0032] This embodiment provides a magnetic field-assisted extrusion bio-3D printing device, such as... Figures 1-2 As shown, the system includes an extrusion system connected to a three-axis linkage mechanism. A workpiece stage is located below the extrusion system. The extrusion system includes a bio-ink cylinder with its axis arranged vertically. The bio-ink cylinder is used to hold bio-ink. The bio-ink cylinder is connected to a two-axis linkage mechanism. A nozzle is located at the bottom of the bio-ink cylinder. The bio-ink cylinder is also connected to a pneumatic mechanism, which is used to introduce gas into the bio-ink cylinder to extrude the bio-ink through the nozzle. The pneumatic mechanism includes an air pipe 3, which is connected to the top of the bio-ink cylinder. The air pipe is also connected to an air pump to pump air into the bio-ink cylinder. The two-axis linkage mechanism is used to drive the extrusion system to move vertically and along a first horizontal direction. The workpiece stage 1 is connected to a horizontal moving mechanism, which can drive the workpiece stage 1 to move along a second horizontal direction, which is perpendicular to the first horizontal direction. The two-axis linkage mechanism and the horizontal moving mechanism enable the nozzle to move along a set path to achieve workpiece forming.

[0033] The above structure can be achieved using existing bio-3D printing devices; further structural details will not be described here.

[0034] In this embodiment, improvements are made to the current bio-3D printing device.

[0035] The bio-ink cartridge contains bio-ink containing magnetic materials, which can be magnetic particles or magnetic fibers.

[0036] A support platform 4 is set in the workpiece forming area of ​​the workpiece stage, and bio-ink is deposited on the upper surface of the support platform 4 to achieve workpiece forming.

[0037] The support platform 4 adopts a cavity structure, inside which there are multiple turns of electromagnetic coil 5. The electromagnetic coil 5 is connected to the control system through a magnetic field controller. When the electromagnetic coil 5 is energized, it can generate a magnetic field, which can generate a vertical magnetic force on the bio-ink containing magnetic materials.

[0038] In this embodiment, the support platform 4 adopts a cuboid structure with a cuboid cavity inside. For a coil 5, the electromagnetic coil 5 is distributed along a rectangular trajectory, with the outermost electromagnetic coil 5 distributed along the edge of the cavity inside the support platform. The generated magnetic field can cover the entire printing area and the area around the nozzle, creating conditions for the precise forming of bio-ink during the printing process.

[0039] The magnetic field controller is connected to the control system. Based on the magnetic properties of the printed model and the bio-ink, it precisely controls the magnitude and direction of the current in the electromagnetic coil 5, thereby achieving dynamic adjustment of the magnetic field strength and direction.

[0040] The support platform 4 is also equipped with multiple magnetic field strength sensors. These sensors are distributed circumferentially within the cavity of the support platform 4. In this embodiment, magnetic field strength sensors are installed on all four surfaces of the cavity inside the support platform 4. The magnetic field strength sensors are connected to the control system. The magnetic field strength is measured in real time through the magnetic field strength sensors, and the data is fed back to the magnetic field control system to ensure the accuracy and stability of the magnetic field and meet the magnetic manipulation requirements of the bio-ink during the printing process.

[0041] For the extrusion system, improvements are made to the current structure. First, the surface of the internal flow channel of the printhead is magnetorheologically polished and galvanized, which gives the internal flow channel of the printhead excellent lubricity, effectively reducing the frictional resistance of bio-ink in the basic process and ensuring smooth extrusion of bio-ink.

[0042] A first heating element and a temperature sensor are installed on the outer surface of the bio-ink cartridge. The heating element precisely heats the bio-ink within the cartridge based on its composition and rheological properties. By adjusting the heating temperature, key rheological parameters such as viscosity and flowability of the bio-ink can be accurately altered, ensuring the bio-ink is in an optimal extrudable state before entering the printhead. This heating method effectively avoids problems such as excessively high viscosity and poor flowability caused by excessively low bio-ink temperatures, thereby reducing the likelihood of printhead clogging.

[0043] In this embodiment, the first heating element is a resistance heating block wrapped around the outer surface of the bio-ink cartridge.

[0044] The outer surface of the support platform 4 is coated with a titanium alloy, which has good biocompatibility and low adhesion. The support platform is also equipped with a second heating element and a temperature sensor. Both the second heating element and the temperature sensor are connected to the control system to adjust the temperature of the support platform 4. The temperature of the support platform 4 can be dynamically adjusted according to the curing requirements of different biological materials, providing suitable environmental conditions for the stable molding of biological structures during the printing process.

[0045] In this embodiment, the second heating element is a resistance heating block fixed inside the support platform.

[0046] The control system is the core of the entire printing device. It receives feedback from multiple sensors, including a liquid level monitoring device, a pressure sensor, and a magnetic field sensor, and comprehensively regulates the operating parameters of the extrusion system, the three-axis linkage mechanism, the pneumatic mechanism, the electromagnetic coil 5, and the support platform 4. The liquid level monitoring device is installed inside the bio-ink cartridge, and the pressure sensor is installed inside the air tube. Based on the preset printing model and the characteristic parameters of the bio-ink, the control system precisely controls the nozzle's movement trajectory, the bio-ink extrusion speed, the strength and direction of the magnetic field, and the temperature of the support platform, ensuring the high efficiency, stability, and high precision of the entire printing process, thus achieving magnetic field-assisted bio-3D printing.

[0047] In this embodiment of the 3D printing device, the electromagnetic coil 5 generates a magnetic field, applying a vertical magnetic force to the bio-ink. This alters the rheological properties of the bio-ink, preventing problems such as nozzle clogging and uneven ink extrusion. The resulting ink has a more regular shape at the nozzle exit, effectively controlling the flow and extrusion of the bio-ink within a very small diameter nozzle. This makes it possible to manufacture intricate biological structures, overcoming the previous bottleneck of achieving extremely small sizes due to nozzle clogging and other issues. The ability to print with extremely small diameters greatly expands the application areas of bio-3D printing technology. In drug development, it can create micro-tissue models that more closely resemble the human physiological environment for drug screening. In personalized medicine, it can print customized implants with intricate structures according to the specific needs of patients, improving the compatibility and integration of implants with the patient's own tissues, and providing patients with better medical solutions.

[0048] Specifically:

[0049] This external magnetic field can directly act on the magnetic components in the bio-ink. From a microscopic perspective, it can break the tendency of cells or biopolymers to aggregate due to their own physicochemical properties. For example, the magnetic force can separate aggregated cell or polymer particles, thereby reducing the viscosity of the bio-ink and improving its flowability.

[0050] From a macroscopic perspective, the external force provided by the magnetic field can create a dynamic environment inside the printhead that facilitates the flow of bio-ink. It's similar to adding an extra thrust to a clogged pipe, allowing the bio-ink to pass more smoothly through the extremely small diameter printhead. This external force effectively reduces the residence time of the bio-ink within the printhead, lowering the likelihood of clogging and ultimately enabling printing at extremely small diameters.

[0051] In addition, the electromagnetic coil 5 is located on the support platform 4. Compared with the electromagnetic coil 5 being located on the printhead, this avoids the defect that the heat generated by the electromagnetic coil 5 when energized affects the gelation state of the bio-ink in the bio-ink cartridge. The electromagnetic coil 5 is located on the support platform 4, which allows the electromagnetic coil to be distributed over a larger range. If the magnetic material is made of magnetic fiber, the magnetic force can be applied at the same time to achieve the directional alignment of the magnetic fiber in the printed part, promote the directional growth of cells, and improve the performance of the printed part.

[0052] Example 2

[0053] This embodiment provides a working method for the magnetic field-assisted extrusion bio-3D printing device described in Embodiment 1:

[0054] like Figure 3 As shown, the process begins with preparing bio-inks, which contain cells, biopolymers, and specific magnetic nanoparticles. The prepared biomaterials are loaded into their respective cartridges. Simultaneously, the first heating element and temperature sensor at the bio-ink cartridge are activated to heat the bio-ink within the cartridge. Once the temperature stabilizes within the optimal printing temperature range for each bio-ink, achieving the appropriate viscosity, the printing operation is ready to begin. The 3D biological model data is imported into the control system. The control system performs layered processing on the model according to the set printing accuracy requirements, converting the 3D model into a series of 2D printing paths and parameter information. This information serves as the guide for nozzle movement and material extrusion during the printing process. The two-axis linkage mechanism and the horizontal movement mechanism work together to drive the extrusion system along the preset path within the control system. The extrusion system operates by using air pressure via an air pump to extrude the bio-ink containing magnetic materials from the bio-ink cartridge, which is then sprayed from the nozzle onto the support platform 4 to form the printed part.

[0055] As the printhead extrudes bio-ink, the magnetic field generated by the electromagnetic coil 5 begins to act around it. Because the bio-ink contains magnetic materials, the magnetic field exerts a magnetic force on it, altering the rheological properties of the bio-ink and preventing problems such as printhead clogging and uneven ink extrusion, resulting in a more regular ink shape at the printhead exit. Under the coordination of the control system, the printhead moves along a preset path. Based on model requirements, the magnetic field strength, printhead movement speed, and ink extrusion speed are dynamically adjusted. The magnetic field guides the ink deposition direction, while the support stage temperature regulation ensures stability and biocompatibility, achieving high-precision printing.

[0056] During the printing process, the control system precisely coordinates parameters such as magnetic field strength, direction, printing speed, printing height, and air pressure, based on the structural characteristics and material requirements of different parts of the 3D model.

[0057] The printing process continues, with the nozzle moving along a predetermined path and extruding biological material under the control of the control system until the entire three-dimensional biological tissue is printed according to the model requirements, resulting in a finished biological tissue product that meets expectations.

[0058] In this embodiment, the diameter of the nozzle is 0.05mm, 0.1mm, or 0.15mm.

[0059] The magnetic field strength generated by the electromagnetic coil 5 ranges from 0.2 to 0.6 T, and the direction of the magnetic field can be dynamically adjusted in three-dimensional space according to the printing path.

[0060] The first heating element adjusts the heating temperature of the bio-ink within the range of 15-35℃.

[0061] The air pressure generated by the air pump can be adjusted within the range of 15-50 MPa.

[0062] The two-axis linkage mechanism and the horizontal moving mechanism drive the printing speed of the printed parts to 1-10mm / s, and the printing height, that is, the distance between the nozzle and the top surface of the deposited material, can be adjusted within the range of 0.1-5mm.

[0063] The bio-ink is a mixture of collagen and agarose containing kidney tissue cells and magnetic materials. It is formed by adding the mixture of collagen, agarose, and magnetic materials to a cell suspension. The collagen concentration is 9 wt%, and the agarose concentration is 7 wt%. The added magnetic material is manganese-zinc ferrite nanoparticles with a concentration of 2.5 wt%. The solvent used is deionized water with a mass fraction of 80.5 wt%. The kidney tissue cells used are renal tubular epithelial cells with a cell density of 1.2 × 10⁻⁶ cells / year. 6 The renal tubular epithelial cell suspension, expressed in cells / ml, is primarily composed of cells and culture medium, with a ratio of 10 wt% cells and 90 wt% culture medium. The renal tubular epithelial cell suspension constitutes 1 wt% of the total bioink mass.

[0064] Alternatively, the bio-ink is a mixture of hyaluronic acid and polyvinyl alcohol containing alveolar wall tissue cells and magnetic materials. It is formed by adding the mixture of hyaluronic acid, polyvinyl alcohol, and magnetic materials to a cell suspension. The concentration of hyaluronic acid is 10 wt%, the concentration of polyvinyl alcohol is 12 wt%, and the magnetic material is nickel-zinc ferrite nanoparticles with a concentration of 1.6 wt%. The solvent used is deionized water with a mass fraction of 75.4 wt%. The alveolar wall tissue cells are alveolar epithelial cells, and the alveolar epithelial cell density is 1.5 × 10⁻⁶ cells / day. 6 The cell suspension, measured in cells / ml, is primarily composed of cells and culture medium, with a ratio of 10 wt% cells to 90 wt% culture medium. The alveolar epithelial cell suspension constitutes 1 wt% of the total bioink mass.

[0065] Alternatively, the bio-ink is a mixture of fibrin and polyethylene glycol containing vascular tissue cells and magnetic materials. It is formed by adding the mixture of fibrin, polyethylene glycol, and magnetic materials to a cell suspension. The fibrin concentration is 6 wt%, the polyethylene glycol concentration is 4 wt%, and the magnetic material is cobalt ferrite nanoparticles with a concentration of 1.8 wt%. The solvent used is deionized water with a mass fraction of 87.2 wt%. The vascular tissue cells are endothelial cells with an endothelial cell density of 2 × 10⁻⁶ cells / day. 6 The endothelial cell suspension, expressed in cells / ml, is primarily composed of cells and culture medium, with a ratio of 10 wt% cells and 90 wt% culture medium. The cell suspension constitutes 1 wt% of the total bioink mass.

[0066] In the first specific implementation of this embodiment, the method includes the following steps:

[0067] Step 1: Assemble the overall manufacturing equipment.

[0068] Assemble the extrusion system, electromagnetic coil, and support platform, ensuring that all components are securely connected and accurately positioned, and check the communication and collaborative capabilities between the parts.

[0069] Step 2: Bio-ink Preparation

[0070] Based on the required total amount of materials, weigh out collagen at a concentration of 9 wt%, dissolve it in 40.5 wt% deionized water, and stir until homogeneous. Weigh out agarose at a concentration of 7 wt%, dissolve it in 40 wt% deionized water by heating, and then cool to a suitable temperature. Weigh out manganese-zinc ferrite nanoparticles at a concentration of 2.5 wt% and disperse them by ultrasonication. Under sterile conditions, mix the collagen solution and agarose solution evenly. Then slowly add the magnetic nanoparticle suspension and stir until homogeneous. Finally, add 1 wt% renal tubular epithelial cell suspension and gently stir to ensure uniform cell distribution, completing the material preparation.

[0071] Step 3: Magnetic field-assisted bioprinting

[0072] The 3D biological model data is imported into the control system. This model data can be a biological tissue structure model acquired and processed through medical imaging technologies (such as CT and MRI), or a specific model generated according to design requirements. The heating module heats the biological ink in the barrel according to the composition and preset parameters of the biological ink, adjusting the viscosity of the biological ink to a suitable state for extrusion. Once the temperature stabilizes at 25℃, the printing operation is started. The printing pressure is 20MPa, the printing speed is 3mm / s, the printing height is 2mm, the nozzle diameter is 0.1mm, and the magnetic field strength is 0.3T. The kidney structure precursor is printed layer by layer.

[0073] Step 4: Post-processing.

[0074] After printing the entire model, it is washed with PBS. The processed prints are stored under suitable environmental conditions to maintain their structure and cell viability, awaiting subsequent applications (such as biomedical research, tissue transplantation, etc.).

[0075] In the second specific implementation of this embodiment, the following steps are included:

[0076] Step 1: Assemble the overall manufacturing equipment.

[0077] Assemble the extrusion system, electromagnetic coil, and support platform, ensuring that all components are securely connected and accurately positioned, and check the communication and collaborative capabilities between the parts.

[0078] Step 2: Material preparation.

[0079] Based on the required total amount of materials, weigh hyaluronic acid at a concentration of 10 wt%, dissolve it in 37 wt% deionized water, and stir continuously until homogeneous. Weigh polyvinyl alcohol at a concentration of 12 wt%, add 38.4 wt% deionized water, heat to dissolve, and cool to a suitable temperature after complete dissolution. Weigh nickel-zinc ferrite nanoparticles at a concentration of 1.6 wt%, and disperse them uniformly using ultrasonic dispersion technology. Under sterile conditions, first thoroughly mix the hyaluronic acid solution and the polyvinyl alcohol solution. Then slowly add the magnetic nanoparticle suspension while continuously stirring. Finally, add 1 wt% of alveolar epithelial cell suspension (cell density 1.5 × 10⁻⁶ cells / mL). 6 (cells / ml), gently stir to distribute the cells evenly in the solution, thus completing the preparation of the alveolar wall tissue bioprinting material.

[0080] Step 3, magnetic field-assisted bioprinting.

[0081] The 3D biological model data is imported into the control system. This model data can be a lung tissue structure model obtained and processed through medical imaging technologies (such as CT and MRI), or a specific model generated according to design requirements. The heating module heats the biological ink in the barrel according to the composition and preset parameters of the biological ink, thereby adjusting the viscosity of the biological ink to a suitable state for extrusion. When the temperature stabilizes at 22℃, the printing operation is started. The printing air pressure is set to 18MPa, the printing speed to 2.5mm / s, the printing height to 1.8mm, the nozzle diameter to 0.1mm, and the magnetic field strength to 0.25T. The alveolar wall structure precursor is printed layer by layer according to the above parameters.

[0082] Step 4, post-processing.

[0083] After the entire model printing process is complete, the printed parts are cleaned with PBS (phosphate-buffered saline). The treated printed parts are then stored under suitable environmental conditions to maintain their structural integrity and cell viability for subsequent applications, such as biomedical research and tissue transplantation.

[0084] In the second specific implementation of this embodiment, the following steps are included:

[0085] Step 1: Assemble the overall manufacturing equipment.

[0086] Assemble the extrusion system, electromagnetic coil, and support platform, ensuring that all components are securely connected and accurately positioned, and check the communication and collaborative capabilities between the parts.

[0087] Step 2: Material preparation.

[0088] Based on the required total amount of materials, weigh fibrin at a concentration of 6 wt%, dissolve it in 45 wt% deionized water, and stir thoroughly until homogeneous. Weigh polyethylene glycol at a concentration of 4 wt%, dissolve it in 42.2 wt% deionized water, and cool to a suitable temperature. Weigh cobalt ferrite nanoparticles at a concentration of 1.8 wt%, and disperse them using ultrasound. Under sterile conditions, mix the fibrin solution and polyethylene glycol solution thoroughly, then slowly add the magnetic nanoparticle suspension, stirring until homogeneous. Finally, add 1 wt% endothelial cell suspension (cell density 2 × 10⁻⁶ cells / mL). 6 (cells / ml), gently stir to distribute the cells evenly, and complete the preparation of the vascular tissue bioprinting material.

[0089] Step 3, magnetic field-assisted bioprinting.

[0090] The 3D vascular biomodel data is imported into the control system. This model data can be a vascular tissue structure model acquired and processed through medical imaging technology (such as CT and MRI), or a specific model generated according to design requirements. The heating module heats the bio-ink in the barrel according to the composition and preset parameters, adjusting the viscosity of the bio-ink to a suitable state for extrusion. Once the temperature stabilizes at 28℃, the printing operation is started. The printing air pressure is set to 22MPa, the printing speed to 4mm / s, the printing height to 2.2mm, the nozzle diameter to 0.2mm, and the magnetic field strength to 0.35T. The vascular structure precursor is printed layer by layer according to the set parameters.

[0091] Step 4, post-processing.

[0092] After printing the entire vascular model, the printout is cleaned with a suitable cleaning solution (such as a buffer solution that simulates the physiological environment). The treated printout is then stored under suitable environmental conditions to maintain its structural stability and cell viability, awaiting subsequent applications such as biomedical research and vascular tissue repair.

[0093] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A method for operating a magnetic field-assisted extrusion bio-3D printing device, characterized in that, The extrusion system moves along a preset path within the control system. When the extrusion system is working, it uses air pressure to extrude the bio-ink containing magnetic materials from the bio-ink barrel and spray it onto the support platform through the nozzle to shape the workpiece. During the shaping process, the electromagnetic coil in the support platform is energized to generate a magnetic field, which applies a vertical magnetic force to the bio-ink containing magnetic materials, thereby changing the rheological properties of the bio-ink. The magnetic field-assisted extrusion bio-3D printing device includes an extrusion system with a vertically oriented axis. The extrusion system has a bio-ink cartridge, the bottom of which is connected to a nozzle. The bio-ink cartridge is also connected to a pneumatic mechanism. A workpiece stage is provided below the extrusion system. The bio-ink cartridge is used to hold bio-ink containing magnetic materials. The workpiece forming area of ​​the workpiece stage is provided with a support platform. An electromagnetic coil is provided inside the support platform. The electromagnetic coil is connected to the control system through a magnetic field controller to apply a vertical magnetic field force to the bio-ink in the extrusion system. The nozzle diameter is 0.1mm~0.2mm.

2. The working method as described in claim 1, characterized in that, The support platform is equipped with multiple electromagnetic coils distributed in a closed loop inside.

3. The working method as described in claim 1, characterized in that, The inner side of the support platform is equipped with multiple magnetic field strength sensors distributed in a circumferential direction, and the magnetic field strength sensors are connected to the control system.

4. The working method as described in claim 1, characterized in that, The outer periphery of the bio-ink cartridge is provided with a first heating element connected to the control system for heating the bio-ink inside the bio-ink cartridge; Furthermore, the first heating element is a resistance heating block.

5. The working method as described in claim 1, characterized in that, The support platform is equipped with a second heating element and a temperature sensor inside the support platform. The second heating element and the temperature sensor are connected to the control system to regulate the temperature of the support platform. Furthermore, the second heating element is a resistance heating block disposed within the support platform.

6. The operating method of the magnetic field-assisted extrusion 3D printing device as described in claim 1, characterized in that, The magnetic field strength applied by the electromagnetic coil ranges from 0.2T to 0.6T.

7. The working method of the magnetic field-assisted extrusion 3D printing device as described in claim 1, characterized in that, The pressure range for extruding bio-ink is 15-50 MPa.

8. The operating method of the magnetic field-assisted extrusion 3D printing device as described in claim 1, characterized in that, The bio-ink cartridge is provided with a first heating element on its outer periphery, which controls the temperature of the bio-ink inside the bio-ink cartridge to be 15-35℃.

9. The operating method of the magnetic field-assisted extrusion 3D printing device as described in claim 1, characterized in that, The magnetic material in the bio-ink is either a magnetic particle material or a magnetic fiber material.

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