Extrusion and photocuring coupled biological 3D printing device and method

Abstract

The invention relates to an extrusion and photocuring coupled biological 3D printing device and method.The extrusion and photocuring coupled biological 3D printing device comprises an extrusion printing execution module and a projection photocuring module, and a deposition platform moves in the horizontal direction and is used for bearing pre-configured photocuring type biological ink and receiving extrusion type biological ink generated by an extrusion module after the photocuring type biological ink is cured; the movement module drives the extrusion module and the projection light curing module to move in the vertical direction and drives the deposition platform to move in the horizontal direction, and needed workpieces are printed layer by layer. Extrusion type 3D printing and photocuring type 3D printing are combined together, different materials can be used in one workpiece to prepare the workpiece, heterogeneity of natural biological tissue can be simulated, and the requirements of the fields of tissue engineering, regenerative medicine, medicine development and the like are met.

Description

Technical Field

[0001] The present invention relates to the technical field of 3D printing, and in particular to a biological 3D printing device and method coupled with extrusion and photocuring. Background Art

[0002] The statements in this section merely provide background information related to the present invention and do not necessarily constitute prior art.

[0003] Bio 3D printing technology is a technology based on the idea of ​​additive manufacturing. It uses computer 3D models to accurately control the spatial position of living cells, biomaterials, and biochemical factors, and prints complex biomimetic biological tissue structures layer by layer. In the fields of tissue engineering, regenerative medicine, and drug screening, bio 3D printing technology has become a key tool to promote development.

[0004] Traditional extrusion biological 3D printing technology forms a three-dimensional structure by extruding biological ink layer by layer. Although it plays an important role in the construction of customized biological tissues, its printing efficiency is relatively low.

[0005] At the same time, projection photocuring technology, such as digital light processing (DLP), can quickly cure hydrogel materials with photosensitive groups such as GelMA. Although it has significant advantages in speed and accuracy, this technology is limited in its applicability to materials without photosensitive groups, that is, not all bio-inks are suitable for the photocuring process.

[0006] Since natural tissues are heterogeneous, an ideal biological 3D printing technology should be able to support the simultaneous printing of multiple biological materials, so as to obtain tissues or materials that meet the heterogeneity requirements, so as to more accurately simulate the complex structural characteristics of natural tissues. Traditional extrusion biological 3D printing technology and projection light curing technology can only print a single material and cannot meet the requirements of heterogeneity. Summary of the invention

[0007] In order to solve the technical problems existing in the above-mentioned background technology, the present invention provides a biological 3D printing device and method coupled with extrusion and photocuring, which improves the printing speed, enhances the diversity of printing materials, and more effectively simulates the heterogeneity of natural tissues to meet the growing technical needs in the fields of tissue engineering, regenerative medicine and drug development.

[0008] In order to achieve the above object, the present invention adopts the following technical solution:

[0009] The first aspect of the present invention provides a biological 3D printing device coupled with extrusion and photocuring, comprising:

[0010] The extrusion module moves in the vertical direction and is used to squeeze the barrel by mechanical force, so that the extruded bio-ink is accumulated layer by layer in the deposition platform through the nozzle to achieve extrusion printing;

[0011] The projection light curing module moves in the vertical direction and is used to solidify the pre-configured light-curable bio-ink through the nozzle according to the light source of the set wavelength and accumulate it layer by layer in the deposition platform to achieve light curing printing;

[0012] The deposition platform moves in a horizontal direction and is used to carry the pre-configured photocurable bio-ink, and the nozzles of the extrusion module and the projection photocuring module are both located below the liquid surface of the photocurable bio-ink;

[0013] The motion module prints the required workpiece layer by layer by driving the extrusion module and the projection light curing module to move in the vertical direction and driving the deposition platform to move in the horizontal direction.

[0014] Furthermore, the extrusion module is connected to the loading platform and has a barrel for loading extruded bio-ink. The opening of the barrel is connected to the print head. The barrel receives mechanical force from the ejection plate, so that the extruded bio-ink is extruded through the print head into the deposition platform.

[0015] Furthermore, the projection light curing module is connected to the loading platform and has a light source. The light source emits ultraviolet light of a set wavelength through the projection head to reach the nozzle below the liquid level of the light-curable biological ink to cure the pre-configured light-curable biological ink.

[0016] Furthermore, polytetrafluoroethylene coating is used on the surface of the photocurable print head and the connecting rod to prevent the bio-ink and the print head from sticking to each other after being inserted into the liquid surface, which would affect the printing effect. Among them, polytetrafluoroethylene has an extremely low friction coefficient and surface energy, making it an ideal choice for preventing adhesion.

[0017] Furthermore, there are multiple groups of print heads, each group of print heads corresponds to a different curing light wavelength of a photocurable biological ink, and each group of print heads has a nozzle for ejecting extruded biological ink.

[0018] Furthermore, the deposition platform includes a material trough and a temperature control module. The material trough is used to hold pre-configured photocurable bio-ink, and the temperature control module keeps the material trough within a set temperature range.

[0019] Furthermore, the motion module drives the loading platform together with the extrusion module and the projection light curing module through motors in the x, y and z directions to realize the movement in the vertical z direction, and drives the deposition platform to realize the movement in the horizontal x and y directions.

[0020] Furthermore, the photocurable bio-ink material includes at least a mixture of water, gelatin methacrylate (GelMA), a photoinitiator, and keratinocytes and fibroblasts.

[0021] Furthermore, the extruded bio-ink material at least includes a mixture of water, gelatin, elastin, hyaluronic acid, collagen and fibroblasts.

[0022] Furthermore, after printing is completed, the printed biological tissue precursor is removed, the residual biological ink on the surface is cleaned, and the final biological 3D printed workpiece is obtained by cross-linking treatment.

[0023] A second aspect of the present invention provides a biological 3D printing method coupled with extrusion and photocuring, comprising the following steps:

[0024] The extruded bio-ink is prepared and stored in a barrel, and the ink is kept in a set viscous flow state by adjusting the temperature;

[0025] Prepare the light-curable bio-ink and place it in the material tank of the deposition platform, and adjust the liquid level and temperature to be within the set range;

[0026] Determine whether the first layer of material to be printed uses extrusion printing or light-curing printing, and perform the corresponding printing by lowering the print head in the vertical direction; if the print head is not replaced after the printing is completed, the current print head continues to print the next layer of material on the first layer of material that has been printed; if the print head is replaced, the print head is replaced while rising in the vertical direction, and then lowered in the vertical direction to complete the printing of the next layer;

[0027] The printing operation is repeated until the desired workpiece is completed, and the final biological 3D printed workpiece is obtained through post-processing.

[0028] Compared with the prior art, one or more of the above technical solutions have the following beneficial effects:

[0029] 1. Combining extrusion 3D printing and photocuring 3D printing can use different materials to prepare workpieces in one workpiece, and can simulate the heterogeneity of natural biological tissues to meet the needs of fields such as tissue engineering, regenerative medicine and drug development.

[0030] 2. The materials for extrusion-type 3D printing are pre-stored in containers, while the materials for photocuring-type 3D printing are placed in the material trough of the deposition platform. The two parts of the materials are stored separately and do not cross when they are not solidified. The temperature and flow state of each material can be independently controlled, further simulating the heterogeneity of natural biological tissues.

[0031] 3. The photocurable 3D printing material is stored in the material tank of the deposition platform before curing, so that the curing nozzle and the extrusion printing nozzle are both located below the liquid surface of the photocurable 3D printing material, so that the photocurable 3D printing material and the extrusion 3D printing material after curing layer by layer can achieve good coupling below the liquid surface, and the uncured photocurable 3D printing material can be added once, without the need for frequent material addition. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0033] Figure 1 is a schematic structural diagram of an extrusion module and a light curing module in a 3D printing device provided by one or more embodiments of the present invention;

[0034] Figure 2 is a schematic diagram of the structure of a deposition platform provided by one or more embodiments of the present invention;

[0035] Figure 3 is a schematic diagram of the structure of a motion module provided by one or more embodiments of the present invention;

[0036] Figure 4 is a schematic diagram of the structure of a 3D printing device provided by one or more embodiments of the present invention;

[0037] Figure 5 It is a schematic diagram of a 3D printing process provided by one or more embodiments of the present invention.

[0038] In the figure, 1-loading platform; 2-connecting plate; 3-extrusion system driving motor; 4-ejection plate; 5-fixing plate; 6-photocuring projection head; 7-extrusion system connecting block; 8-photocuring module connecting block; 9-z-axis driving motor; 10-printer frame; 11-y-axis motion motor; 12-x-axis motion motor; 13-deposition platform connecting plate; 14-connecting member; 15-loading platform; 16-deposition platform; 17-motion module. DETAILED DESCRIPTION

[0039] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0040] It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0041] As introduced in the background technology, traditional extrusion-based 3D bio-printing technology and photocuring-coupled 3D bio-printing technology are difficult to print products that conform to the heterogeneity of natural materials.

[0042] Therefore, the following embodiments provide a biological 3D printing device and method coupled with extrusion and photocuring, aiming to improve the printing speed, enhance the diversity of printing materials, and more effectively simulate the heterogeneity of natural tissues to meet the growing technical needs in the fields of tissue engineering, regenerative medicine, and drug development.

[0043] Embodiment 1:

[0044] A biological 3D printing device coupled with extrusion and photocuring, comprising:

[0045] The extrusion module moves in the vertical direction and is used to squeeze the barrel by mechanical force, so that the extruded bio-ink is accumulated layer by layer in the deposition platform through the nozzle to achieve extrusion printing;

[0046] The projection light curing module moves in the vertical direction and is used to solidify the pre-configured light-curable bio-ink through the nozzle according to the light source of the set wavelength and accumulate it layer by layer in the deposition platform to achieve light curing printing;

[0047] The deposition platform moves in a horizontal direction and is used to carry the pre-configured photocurable bio-ink, and the nozzles of the extrusion module and the projection photocuring module are both located below the liquid surface of the photocurable bio-ink;

[0048] The motion module prints the required workpiece layer by layer by driving the extrusion module and the projection light curing module to move in the vertical direction and driving the deposition platform to move in the horizontal direction.

[0049] The extrusion module has a barrel for loading extrusion-type bio-ink material. The opening of the barrel is connected to the nozzle of the print head to ensure that the bio-ink can be extruded at a constant speed and pressure. In addition, the extrusion module is also equipped with a temperature control system to keep the bio-ink within a suitable temperature range. In the extrusion module, the extrusion system is fixed to the loading platform 1 through a connecting block 7, such as Figure 1 As shown, a connecting plate 2 is provided on the connecting block 7, an extrusion system driving motor 3 is provided on the connecting plate 2, an output shaft of the extrusion system driving motor 3 is connected to a screw assembly, a fixed plate 5 is provided at the end of the screw assembly, and a push-out plate 4 is movably connected to the screw assembly. The motor 3 drives the screw assembly to rotate so that the push-out plate 4 moves in a straight line. When a certain biological ink material is needed, the material is loaded into a barrel, and the barrel is loaded on the extrusion system. The barrel is extruded by the linear motion of the push-out plate 4 so that the extruded biological ink material is extruded.

[0050] The photocuring module is mainly composed of a high-precision ultraviolet light source, which can emit ultraviolet light of a specific wavelength to activate the photoinitiator contained in the photocurable bio-ink. By precisely controlling the irradiation range and time of the ultraviolet light, a layer of rapid and precise curing can be achieved. In the projection photocuring module, multiple DLP projectors are coupled to the same loading platform 1 of the extrusion module. The DLP projector is composed of a light source, optical elements, a digital micromirror device, a control system and a cooling system. Among them, the light source can be of different wavelengths in order to cure heterogeneous tissues with different mechanical property requirements. In this embodiment, Figure 1 As shown, the light curing projection head 6 of the light curing module is connected to the loading platform 1 through a connecting block 8, and the light sources with different wavelengths generated are emitted through the nozzles of the print head.

[0051] The deposition platform 16 is composed of a material tank and a temperature control module. Figure 2 As shown, the material tank is located above the temperature control module, and the material tank is prepared into a cylindrical groove shape to hold the light-cured cell-carrying biological ink material. The temperature control module is mainly composed of Peltier.

[0052] The motion module 17 drives the loading platform 1 together with the extrusion module and the projection light curing module through motors in the x, y and z directions, and drives the deposition platform to move at the same time, and through joint cooperation, controls the precise movement of the print head.

[0053] The motor for xy plane motion drives the deposition platform, the motor for z axis motion drives the extrusion module and the photocuring module, and moves the print head up and down. The motion module consists of a stepper motor, a transmission system, a guide rail and a slider, a motion controller and a limit switch, a frame structure and a sensor.

[0054] Among them, the nozzles of the extrusion module and the projection light curing module are arranged on the print head, and the nozzles are located below the liquid surface of the photocurable bio-ink in the deposition platform 16. The print head is driven to move up and down in the liquid surface of the photocurable bio-ink through the motion module 17, and the horizontal movement of the deposition platform is coordinated to complete the curing of each layer of the photocurable bio-ink. The extruded bio-ink can be directly extruded below the liquid surface of the photocurable bio-ink using the nozzle by replacing the print head, and coupled with the cured photocurable bio-ink to realize 3D printing of heterogeneous workpieces, which is suitable for the manufacture of some heterogeneous parts in bioengineering.

[0055] Regarding the replacement of the print head, the print head integrates multiple nozzles, including at least nozzles for extruded bio-ink and nozzles for photocurable bio-ink of different wavelengths. Only one nozzle can be used for printing the same layer. After each layer is printed, the nozzle required for the next layer is replaced according to the needs of the workpiece structure. Structurally, the print head has a nozzle holder that is driven by a motor to rotate. Multiple nozzles are installed on the nozzle holder. The motor drives the nozzle holder to rotate to the set position so that the corresponding nozzle reaches the printing working position. The gap between the nozzle and the workpiece is adjusted in coordination with the overall lifting movement of the print head to complete the print head replacement action.

[0056] In this embodiment, Figure 3 and Figure 4 As shown, the motion module includes a z-axis drive motor 9, a y-axis motion motor 11 and an x-axis motion motor 12. The z-axis drive motor 9 is connected to a loading platform 15 through a movable component via a connecting member 14. The loading platform 15 includes a loading platform 1 and an extrusion module and a projection light curing module connected to the loading platform 1. The vertical motion of the loading platform 15 is achieved by the z-axis drive motor 9.

[0057] The x-axis motion motor 12 is connected to the deposition platform connecting plate 13 through a movable component, and the deposition platform connecting plate 13 is connected to the deposition platform 16; the x-axis motion motor 12 realizes the x-direction motion of the horizontal plane of the deposition platform 16;

[0058] The y-axis motion motor 11 is connected to the x-axis motion motor 12 , the deposition table connecting plate 13 and the deposition platform 16 through a movable component, and the y-axis motion motor 11 realizes the y-direction motion of the deposition platform 16 in the horizontal plane.

[0059] The movable component here is not limited to a specific structure, for example, it can be a ball screw structure, using a motor in the corresponding direction to drive the screw to rotate, pushing the ball slider on the screw to make corresponding z-, x- and y-direction movements.

[0060] The motion module enables the deposition platform 16 to complete planar motion during extrusion printing and photocuring, as well as vertical motion when the extrusion module releases the bio-ink material.

[0061] By coupling the advantages of extrusion bioprinting technology and projection light curing technology, multiple materials can be used in a single printing process, which can not only quickly build complex structures, but also simulate the heterogeneity of natural tissues. By adjusting the wavelength of the curing light source, the material concentration (including light-curing materials and extrusion materials), and the printing parameters, the heterogeneity of biological tissues can be precisely controlled, thereby achieving biologically constructed tissues that are closer to the characteristics of real tissues. This technology combines the flexibility of extrusion printing with the efficiency of light curing technology, greatly enhancing the application potential of biological 3D printing.

[0062] In this embodiment, the connecting plate 2 and the extrusion system connecting block are connected by screws, and the photocuring projection head 6 and the photocuring connecting module 8 are connected by welding. There is a driving motor in the loading platform, which can be rotated to switch the nozzles in the print head, so as to switch between extrusion printing and photocuring printing. The connecting plate and the extrusion system connecting block are connected by screws, while the photocuring projection head and the photocuring module connecting block are fixed by welding, which is to ensure stability and durability during the printing process. This design allows the printer to flexibly switch between different printing technologies to meet different printing needs.

[0063] In this embodiment, the z-axis drive motor drives the loading platform to move up and down, and the xy-axis drive motor drives the deposition platform to move in a plane. The entire motion module works together to enable the printer to accurately control the position of the print head, thereby building objects layer by layer in three-dimensional space. The z-axis drive motor controls the vertical movement of the print head, while the xy-axis drive motor controls the movement of the deposition platform in the horizontal plane, which can achieve accurate layer-by-layer printing. The deposition platform connection plate ensures the stability and precise movement of the build platform.

[0064] By precisely controlling printing parameters and temperature, this device can be used to print a variety of biomaterials, including cells, growth factors, and biocompatible materials, to form complex three-dimensional structures.

[0065] In this embodiment, the photocurable bio-ink material is a mixture of methacrylated gelatin (GelMA), hydroxyapatite (HA), keratinocytes, fibroblasts and bone marrow mesenchymal stem cells. After printing, 405nm ultraviolet light is used for cross-linking and curing.

[0066] In this embodiment, the extruded biological ink material is a mixture of gelatin, elastin, hyaluronic acid, collagen, fibroblasts and vascular endothelial cells.

[0067] In this embodiment, the post-treatment is an aqueous cross-linking agent solution or an ultraviolet curing light source.

[0068] In this embodiment, the inner diameter of the nozzle of the print head is 0.16-0.33 mm, and the length is 5-20 mm.

[0069] In this embodiment, the wavelengths of the light sources are 405 nm and 365 nm respectively.

[0070] In this embodiment, the light source wavelength of 405 nm corresponds to the photoinitiator TOP-L, and the light source wavelength of 365 nm corresponds to the photoinitiator TOP.

[0071] The working process of the device in this embodiment is as follows: pre-configure the photocurable bio-ink and transfer it to the material tank of the deposition platform for standby. Configure the extruded bio-ink and transfer it to the material barrel for standby, and adjust the temperature control component to make it in a suitable viscous flow state. Import the designed 3D model and determine which print head to use for loading the material. Printing follows the schematic diagram. Figure 5 After printing, use UV light or a cross-linking agent to cross-link.

[0072] The printing parameters are selected as follows: the printing pressure of the extrusion module is 10-20N; the printing speed of the extrusion module is 50-300mm / min; the exposure time used for printing in the light curing module is 1-3 seconds / layer; the layer thickness used for printing in the light curing module is 50um-100um; the lifting speed used for printing in the light curing module is 1-5mm / s; the wavelength of the light curing light source is 405nm and 365nm.

[0073] By coupling extrusion bioprinting technology and projection light curing technology, multiple materials can be used in a single printing process, which not only significantly improves printing efficiency and accuracy, but also better simulates the heterogeneity of natural tissues. Extrusion printing technology can handle high-viscosity bio-inks, while projection light curing technology can achieve high-precision curing in a short time. The combination of the two can support a wider range of biomaterials and enhance the functionality and biological effectiveness of printed structures. By precisely controlling the wavelength of the curing light source, material concentration, and printing parameters, cell viability can be maximized, the printing process can be optimized, and structural stability can be improved. In addition, this coupling technology can significantly reduce costs, improve material utilization, and expand application areas to better meet the diverse needs of fields such as tissue engineering, regenerative medicine, and drug development.

[0074] Embodiment 2:

[0075] A method for biological 3D printing coupled with extrusion and photocuring, comprising the following steps:

[0076] The extruded bio-ink is prepared and stored in a barrel, and the ink is kept in a set viscous flow state by adjusting the temperature;

[0077] Prepare the light-curable bio-ink and place it in the material tank of the deposition platform, and adjust the liquid level and temperature to be within the set range;

[0078] Determine whether the first layer of material to be printed uses extrusion printing or light-curing printing, and perform the corresponding printing by lowering the print head in the vertical direction; if the print head is not replaced after the printing is completed, the current print head continues to print the next layer of material on the first layer of material that has been printed; if the print head is replaced, the print head is replaced while rising in the vertical direction, and then lowered in the vertical direction to complete the printing of the next layer;

[0079] The printing operation is repeated until the desired workpiece is completed, and the final biological 3D printed workpiece is obtained through post-processing.

[0080] Post-processing, specifically, after printing is completed, the printed biological tissue precursor is removed from the cell-laden biological ink, and the residual biological ink on the surface is cleaned with PBS (phosphate buffered saline), and then cross-linked under ultraviolet light or in a cross-linking agent.

[0081] Preferably, the crosslinking agent is an aqueous crosslinking agent solution.

[0082] More preferably, in the aqueous crosslinking agent solution, the concentration of EDC (1-ethyl-(3-dimethylaminopropyl)carbodiimide) is 20-50 mg / ml, and the concentration of NHS (N-hydroxysuccinimide) is 2-5 mg / ml.

[0083] The solvent of the crosslinking agent solution is 60-80% alcohol; the preparation method of the aqueous crosslinking agent solution is to dissolve EDC and NHS in 60-80% (% is volume percentage) alcohol aqueous solution, and mix at 20-30°C and 1000rpm for 20-40min.

[0084] In this embodiment, the printing push force of the extrusion module is 10-20N.

[0085] In this embodiment, the printing speed of the extrusion module is 50-300 mm / min.

[0086] In this embodiment, the exposure time used by the light curing module for printing is 1-15 seconds per layer.

[0087] In this embodiment, the layer thickness used for printing by the light curing module is 50um-100um.

[0088] In this embodiment, the lifting speed of the light curing module used for printing is 1-5 mm / s.

[0089] Embodiment three:

[0090] The method for performing biological 3D printing using the device of embodiment 1 comprises the following steps:

[0091] Assemble the extrusion module. Install the barrel on the loading platform, and then install the nozzle at the barrel outlet, making sure the nozzle can be tightly connected to the barrel. Install the temperature control component near the barrel to ensure that the temperature can be accurately controlled. Above the loading platform, install the piston assembly and adjust the positioning to ensure smooth extrusion of the bio-ink.

[0092] Assemble the light curing module. Install the light source in the designated position, ensure that the light source is aligned with the projection head, and adjust the position of the projection head to ensure that the projected image is clear.

[0093] Assemble the mechanical components. Install the xy plane motion assembly on the deposition platform to ensure smooth movement of each axis. Install the loading stage that holds multiple print heads on the z axis to ensure free movement of the z axis.

[0094] After the mechanical components are installed, check and test the movement of each axis to ensure there are no abnormalities.

[0095] Prepare extruded bio-ink material and photocurable bio-ink material. Mix RO water, gelatin, hyaluronic acid, and elastin in a calculated ratio, stir at 65°C and 950rpm for 30 minutes to obtain a premix (the concentrations of gelatin, hyaluronic acid, and elastin are 7.5wt%, 0.5wt%, and 2wt%, respectively). Add vascular endothelial cells to the mixed premix at a cell density of 106 cel ls / ml to obtain an extruded bio-ink material. Subsequently, load the extruded bio-ink material into the barrel.

[0096] RO water and GelMA powder, photoinitiators TPO and TPO-L were mixed in the calculated ratio, stirred at 60°C and 850rpm for 30 minutes to obtain a premix (GelMA concentration was 10wt%, photoinitiator concentration was 1wt%). Fibroblasts and keratinocytes were added to the premix, with cell densities of 5×106cells / ml and 106cells / ml, respectively. Subsequently, the photocurable bio-ink material was loaded into the trough of the deposition platform.

[0097] Use a print head equipped with a 365nm light source to cure a layer first, with a curing thickness of 50um and an exposure time of 1 second. After curing is completed, the loading platform rises at a speed of 3mm / s to 10cm from the deposition platform and is converted into an extrusion print head. After the conversion is completed, the print head descends to the already cured layer on the deposition platform and prints a single layer of 0.16mm thick blood vessel layer, with a printing push force of 15N and a printing speed of 100mm / min. After printing is completed, the print head rises and is converted to a print head with a 365nm light source again. The same parameters are used to cure a layer, and then the same operation is repeated 5 times to complete the first part of the printing.

[0098] Next, the print head was switched to a 405 nm light source and two layers were cured, with a thickness of 50 μm per layer and an exposure time of 3 seconds.

[0099] After printing, the residual bio-ink on the surface was washed with PBS, and post-processed with a 405nm official for 5 minutes. The final printed skin tissue precursor was obtained, and then the precursor was placed in 37°C, 5% CO2 for tissue culture. After 14 days, the printed human-like skin was taken out.

[0100] Embodiment 4:

[0101] The method for performing biological 3D printing using the device of Example 1 has the following specific steps:

[0102] Assemble the extrusion module. Install the barrel on the loading platform, and then install the nozzle at the barrel outlet, making sure the nozzle can be tightly connected to the barrel. Install the temperature control component near the barrel to ensure that the temperature can be accurately controlled. Above the loading platform, install the piston assembly and adjust the positioning to ensure smooth extrusion of the bio-ink.

[0103] Assemble the light curing module. Install the light source in the designated position, ensure that the light source is aligned with the projection head, and adjust the position of the projection head to ensure that the projected image is clear.

[0104] Assemble the mechanical components. Install the xy plane motion assembly on the deposition platform to ensure smooth movement of each axis. Install the loading stage that holds multiple print heads on the z axis to ensure free movement of the z axis.

[0105] After the mechanical components are installed, check and test the movement of each axis to ensure there are no abnormalities.

[0106] Prepare extruded bio-ink material and photocurable bio-ink material. Mix RO water, gelatin, hyaluronic acid, and elastin in a calculated ratio, stir at 50°C and 950rpm for 30 minutes to obtain a premix (the concentrations of gelatin, hyaluronic acid, and elastin are 5wt%, 1.5wt%, and 1wt%, respectively). Add vascular endothelial cells to the mixed premix at a cell density of 105cells / ml to obtain an extruded bio-ink material. Subsequently, load the extruded bio-ink material into the barrel.

[0107] RO water, GelMA powder, photoinitiator TPO-L and hydroxyapatite powder were mixed in a calculated ratio and stirred at 50°C and 850rpm for 20 minutes to obtain a premix (GelMA concentration was 15wt%, photoinitiator concentration was 1wt%, and hydroxyapatite concentration was 20wt%). Fibroblasts and bone marrow mesenchymal stem cells were added to the premix, with cell densities of 5×106cells / ml and 107cells / ml, respectively. Subsequently, the photocurable bio-ink material was loaded into the trough of the deposition platform.

[0108] Use a print head equipped with a 405nm light source, cure thickness 100um, exposure time 2 seconds, cure completed, the loading platform rises at a speed of 2mm / s to 10cm from the deposition platform, and converts to an extrusion print head. After the conversion is completed, the print head descends to the already cured structure on the deposition platform, prints a single layer of 0.16mm thick blood vessel layer, prints with a push force of 10N, and prints at a speed of 200mm / min. After printing is completed, the print head rises and converts to a print head with a 405nm light source again, and the parameters are cured until the printing is completed.

[0109] After printing, the residual bio-ink on the surface was washed with PBS, and a 405nm light source was used for post-treatment and irradiation for 5 minutes. The final printed bone tissue precursor was obtained, and then the precursor was placed in 37°C, 5% CO2 for tissue culture. After 14 days, the printed bone tissue was taken out.

[0110] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A biological 3D printing device coupled with extrusion and photocuring, It is characterized in that include: The extrusion module moves in the vertical direction and is used to squeeze the barrel by mechanical force, so that the extruded bio-ink is accumulated layer by layer in the deposition platform through the nozzle to achieve extrusion printing; The projection light curing module moves in the vertical direction and is used to solidify the pre-configured light-curable bio-ink through the nozzle according to the light source of the set wavelength and accumulate it layer by layer in the deposition platform to achieve light curing printing; The deposition platform moves in a horizontal direction and is used to carry the pre-configured photocurable bio-ink, and the nozzles of the extrusion module and the projection photocuring module are both located below the liquid surface of the photocurable bio-ink; The motion module prints the required workpiece layer by layer by driving the extrusion module and the projection light curing module to move in the vertical direction and driving the deposition platform to move in the horizontal direction.

2. A biological 3D printing device coupled with extrusion and photocuring as claimed in claim 1, It is characterized in that The extrusion module is connected to the loading platform and has a barrel for loading extruded bio-ink. The opening of the barrel is connected to the print head. The barrel receives mechanical force from the ejection plate, so that the extruded bio-ink is extruded through the print head into the deposition platform.

3. A biological 3D printing device coupled with extrusion and photocuring as claimed in claim 1, It is characterized in that The projection light curing module is connected to the loading platform and has a light source. The light source emits ultraviolet light of a set wavelength through a projection head to cure the light curing biological ink pre-configured in the deposition platform.

4. A biological 3D printing device coupled with extrusion and photocuring as claimed in claim 2, It is characterized in that The print heads are provided in a plurality of groups, each group of print heads corresponds to a different curing light wavelength of a photocurable biological ink, and each group of print heads has a nozzle for ejecting extruded biological ink.

5. A biological 3D printing device coupled with extrusion and photocuring as claimed in claim 1, It is characterized in that The deposition platform includes a material trough and a temperature control module. The material trough is used to hold pre-configured light-curable biological ink, and the temperature control module keeps the material trough within a set temperature range.

6. A biological 3D printing device coupled with extrusion and photocuring as claimed in claim 1, It is characterized in that The motion module drives the loading platform together with the extrusion module and the projection light curing module in the x, y and z directions to realize the movement in the z direction of the vertical plane, and drives the deposition platform to realize the movement in the x and y directions of the horizontal plane.

7. A biological 3D printing device coupled with extrusion and photocuring as claimed in claim 1, It is characterized in that The photocurable biological ink material at least includes water, methacrylated gelatin, a photoinitiator, and a mixture of keratinocytes and fibroblast bone formation.

8. A biological 3D printing device coupled with extrusion and photocuring as claimed in claim 1, It is characterized in that The extruded biological ink material at least includes a mixture of water, gelatin, elastin, hyaluronic acid, collagen and fibroblasts.

9. A biological 3D printing device coupled with extrusion and photocuring as claimed in claim 1, It is characterized in that After printing is completed, the printed biological tissue precursor is removed, the residual biological ink on the surface is cleaned, and the final biological 3D printed workpiece is obtained by cross-linking treatment.

10. A method for implementing biological 3D printing based on the device according to any one of claims 1 to 9, It is characterized in that The following steps are involved: The extruded bio-ink is prepared and stored in a barrel, and the ink is kept in a set viscous flow state by adjusting the temperature; Prepare the light-curable bio-ink and place it in the material tank of the deposition platform, and adjust the liquid level and temperature to be within the set range; Determine the first layer of material to be printed using extrusion printing or light-curing printing, and perform the corresponding printing by lowering the print head in a vertical direction; If the print head is not replaced after printing is completed, the current print head will continue to print the next layer of material on the first layer of material that has been printed; if the print head is replaced, the print head will rise in the vertical direction while the print head is replaced, and then descend in the vertical direction to complete the next layer of printing; The printing operation is repeated until the desired workpiece is completed, and the final biological 3D printed workpiece is obtained through post-processing.

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