IMAGING PRINCIPLE-BASED INTEGRATED COLOR LIGHT 3D BIOPRINTING SYSTEM

Abstract

An integrally-formed three-dimensional (3D) bio-printing system capable of alternate feeding of multiple materials, comprising: an optical imaging unit and a light path conversion unit, wherein the optical imaging unit comprises an image processing unit and a projection unit, the image processing unit segmenting a 3D modeling graphic of a printed subject to form image information, the projection unit converting the image information into one or more optical images, and the light path conversion unit projects the imaged light paths into bio-ink that can be cured by light, so that the projected image can cure the bio-ink by means of the focus of light.

Claims

1. An imaging principle-based integrated color light 3D bioprinting system, comprising an optical imaging unit configured to allow a printed subject to form one or more optical images; an optical path conversion unit configured to allow an imaging optical path of the one or more optical images to be projected into a bio-ink capable of being cured by light, so that the light allows the projected image optical path to cure the bio-ink by focus of the light.

2. The bioprinting system according to claim 1, wherein the optical imaging unit comprises an image processing unit and a projection unit, wherein the image processing unit converts the printed subject into a digital signal, and the one or more optical images are generated by the projection unit.

3. The bioprinting system according to claim 2, wherein the printing subject is generated in a form of three-dimensional modeling, and the image processing unit cuts graphics of the three-dimensional modeling in different dimensions.

4. The bioprinting system according to claim 3, wherein cutting in different dimensions includes cutting and decomposition along a central peripheral axis of the one or more optical images.

5. The bioprinting system according to claim 4, wherein the cutting further comprises cutting with different curvatures along a circumference of the one or more optical images.

6. The bioprinting system according to claim 5, wherein the projection unit projects the one or more optical images formed by cut surface.

7. The bioprinting system according to claim 1, wherein the bio-ink is in a liquid form and is carried in a curing container.

8. The bioprinting system according to claim 7, wherein the curing container and the optical path conversion unit have a relative motion position.

9. The bioprinting system according to claim 8, wherein the curing container is statically fixed, and the optical path conversion unit moves relative to the curing container.

10. The bioprinting system according to claim 9, wherein a movement of the optical path conversion unit includes a peripheral movement of the optical path conversion unit around the curing container.

11. The bioprinting system according to claim 10, wherein the peripheral movement is a 360-degree movement.

12. The bioprinting system according to claim 8, wherein a glass prism and/or a cylindrical lens are provided outside the curing container.

13. The bioprinting system according to claim 12, wherein the glass prism and/or the cylindrical lens and the optical path conversion unit move synchronously.

14.-44. (canceled)

45. The bioprinting system according to claim 8, wherein the optical path conversion unit is configured to make a circular movement around the curing container.

46. The bioprinting system according to claim 8, wherein the optical path conversion unit converts vertical light into parallel light and makes the light perpendicularly enters the curing container.

47. The bioprinting system according to claim 12, wherein the lens converts the light from the projection unit into parallel light, and a reflecting mirror is configured to project the parallel light vertically into the curing container.

48. The bioprinting system according to claim 8, wherein the optical path conversion unit is arranged to rotate relative to the curing container.

49. The bioprinting system according to claim 17, wherein the system further comprises a rotation angle measuring device to measure an angle at which the optical path conversion unit rotates around the curing container.

50. The bioprinting system according to claim 18, wherein the system further comprises a computer system configured to allow the angle measured by the rotation angle measuring device to adjust an angle of the projected one or more images.

51. The bioprinting system according to claim 1, wherein the bio-ink comprises a light-responsive cross-linking group modified macromolecule, ortho-nitrobenzyl phototrigger modified macromolecule, and a light initiator.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0136] FIG. 1 is a schematic structural view of the feeding system, feed pond and upgrading platform of the present invention;

[0137] FIG. 2 is a schematic diagram of the process of printing 8-color micrometer cubes;

[0138] FIG. 3 is a projection picture of the array of unit cubes 1 and 5 in a batch of 8-color micrometer cubes;

[0139] FIG. 4 is a projection picture of the array of unit cubes 2 and 6 in a batch of 8-color micrometer cubes;

[0140] FIG. 5 is a projection picture of batch printing 3 and 7 arrays of unit cubes in 8-color micrometer cubes;

[0141] FIG. 6 is a projection picture of batch printing of arrays of unit cubes 4 and 8 in 8-color micrometer cubes;

[0142] FIG. 7 is an optical microscope photograph of 8-color micrometer cubes printed in batches through the printing process of FIG. 2;

[0143] FIG. 8 is a schematic diagram of a three-dimensional modeling three-dimensional structure of a printing body according to an embodiment of the present invention;

[0144] FIG. 9 is a three-dimensional model diagram of the superstructure of the structure shown in FIG. 8;

[0145] FIG. 10 is a three-dimensional model diagram of the lower structure of the structure shown in FIG. 8;

[0146] FIG. 11 is a schematic diagram of a division method of image processing of the upper layer structure of FIG. 8;

[0147] FIG. 12 is a photomicrograph of a physical image of the structure shown in FIG. 8 printed by the printing method of the present invention;

[0148] FIG. 13 is a perspective structural view of a printing apparatus in a specific embodiment of the present invention;

[0149] FIG. 14 is an exploded structural diagram of a printing apparatus in a specific embodiment of the present invention;

[0150] FIG. 15 is a schematic diagram of a stereo structure of an optical path conversion unit that can move relatively in a specific embodiment of the present invention;

[0151] FIG. 16 is a cross-sectional view of a relatively moving optical path conversion unit and a cross-sectional structure diagram of a curing container in a specific embodiment of the present invention;

[0152] FIG. 17 is a schematic diagram of the principle of optical path change in a specific embodiment of the present invention;

[0153] FIG. 18 is a schematic diagram of the principle of adjusting the angle of a projected image;

[0154] FIG. 19 is a schematic structural view of keeping the direction of light of the projected image unchanged;

[0155] FIG. 20 is a top view of the structure of FIG. 19; and

[0156] FIG. 21 is a schematic diagram of a method for performing image processing on an angle change measured by a rotation angle.

DETAILED DESCRIPTION OF THE INVENTION

[0157] The present invention provides specific implementation examples to illustrate the printing method of the present invention. It can be understood that these examples are only for further explanation of how to implement the present invention, and do not limit the present invention in any way. The scope of the present invention is subject to the claims.

EXAMPLE 1

Fast Batch Printing for 8-Color Colored Micrometer Cubes

[0158] Bio-ink preparation: 1) 75 mg ortho-nitrobenzyl modified hyaluronic acid (HA-NB), 250 mg methacrylic anhydride modified gelatin (GelMA) and 10 mg phenyl (2,4,6-trimethyl benzoyl) lithium phosphate (LAP) was dissolved in 10 ml of deionized water to prepare a light-controlled 3D printing ink containing 0.75% HA-NB, 2.5% GelMA and 0.1% LAP.

[0159] The structure of the printing device is shown in FIG. 1. The left side is a top view, and the right side is a perspective view. It has three discharge ports A, B, and C to exclude different inks. The lifting platform is located above the printing pool, and the light is projected from below to the printing. In the pool, when printing objects of different materials, it is convenient to exclude different inks, and the type of ink can be easily replaced without causing pollution between the inks. Make printed materials more precise. The type of ink is different, and the structure of the printed object is also complicated.

[0160] For example, as shown in FIG. 2, first build a model of four-unit cube arrays, and project images of four-unit cubes as shown in FIGS. 3-6, and then perform program control according to the established model, and then print. The printing steps are as follows:

[0161] 1. First, set the layer thickness, for example, the unit cube side length is 50 um, then the layer thickness is set to 50 um (number 1 in FIG. 2).

[0162] 2. Provide a layer of ink A with a thickness of 1 unit and select a cube model for projection exposure printing.

[0163] 3. Absorb uncured ink A.

[0164] 4. Keep the layer thickness and height unchanged, for a layer of material B, select the position 2 cube model for projection exposure printing (number 2 in FIG. 2).

[0165] 5. Absorb uncured ink B.

[0166] 6. Repeat steps 2˜5 until the first layer structure is all printed, and the numbers 3 and 4 in FIG. 2 are printed.

[0167] 7. The sample platform rises one level.

[0168] 8. For the two-layer thickness of material E, select the location 1 unit cube model for projection exposure printing (number 5 in FIG. 2).

[0169] 9. Absorb uncured ink E.

[0170] 10. Repeat steps 8˜9 until the second layer structure is completely printed (numbered 5, 6, 7, 8 in FIG. 2), complete the 8-color color micron cube printing and finally obtain the 8-color color batch printing as shown in FIG. 7, the exposure light intensity is 50, and the exposure time of each layer is 1000 ms. This can facilitate the structure of color printing. Among them, the symbols 1, 5, 6, 2 indicate the structure formed by different inks.

[0171] The image projection here can adopt the image processing unit of this invention to perform image processing in the early stage, and then output through the projection device, project into the printing pool, and directly perform light curing on the projected image. For example, the different numbers in FIG. 2 may all be one projection image, and the projection image is just a plurality of identical images superimposed and printed. For example, the number 1 has 50 um, the thickness of each image printed is Sum, then 10 identical images are continuously projected for light curing, and then the number 1 can be printed. By analogy, when the number 2 is another bio-ink, 10 identical projection images 2 are printed with different bio-inks, and the printing of the number 2 is obtained. In this way, if the inks of number 1 and number 2 are different, the materials are different. According to this understanding, this method is more complicated, but the printed structure is more complicated, closer to the structure of the organism itself, and possibly provides for the replacement of human organs.

EXAMPLE 2

3D Printed Cartilage Scaffold for Repairing Osteochondral Defects

[0172] For example, as shown in FIGS. 8, 9, and 10, the target structure to be printed is first modeled, and then program control is performed according to the established model to perform “colorful” volume imaging printing of different materials of different parts of the scaffold.

[0173] For example, the created models are shown in FIGS. 8, 9 and 10. FIG. 8 is a cartilage scaffold model, which consists of two parts, the upper scaffold of FIG. 9 and the lower scaffold of FIG. 10, respectively. The upper scaffold has 30 circular holes in plan view, and 30 circular holes on the side, and each circular hole intersects with each other.

[0174] Taking the above layer structure as an example, the cutting method of the model in this scheme is shown in FIG. 11. The image is cut along the center point 105, and digital information is input in the image processing system. The cutting position can be longitudinal cutting 106, cutting at different angles along the entire cylinder 100. For example, cutting at an angle of 1 degree per arc, in fact, it is cut into countless rectangular parallelepiped faces, but only some faces have no gaps, and some surfaces have gaps. The positions without gaps indicate that no holes are formed, and the gapped positions have holes. The notch can be inside the cuboid or on the edge of the long side. For example, cutting every 1° can actually form 360 faces. When cutting at an angle of 0.5°, 720 faces are formed. Cutting image can be automatically completed in the software, so that the digital information of different faces is formed, and very accurate image construction can be achieved. The digital information is delivered by the projector. Each projection is a cut surface. The light on the surface is reflected by the light and irradiated into the container with bio-ink. An image of the cut surface is formed in the container of bio-ink. Curing is required for curing with focused light, while unfocused light can pass through the bio-ink without curing. In this way, a rectangular parallelepiped surface is formed in the bio-ink, because the 360-degree dimension is performed, so after each cured surface is formed, the optical path system needs to be rotated to change the focus position, and the 360° is completed as the rotation continues. The focusing and curing of multiple different surfaces are completed, and finally completes the printing of the entire model.

[0175] If different tissues or structures, or the structure of each face is different, the first bio-ink can be excluded after forming one face and new different bio-ink can form another face. This face can be of different heights, different thicknesses, or a face with a different structure. In this way, color printing can be easily achieved.

[0176] This design is to use the scaffold for cartilage repair. The top view of the lower scaffold has 30 holes. The purpose of this design is to allow the bone marrow mesenchymal stem cells to migrate to the upper layer and help repair the cartilage. For the design of the upper scaffold, the middle hole is for the bone marrow mesenchymal stem cells to migrate to the cartilage layer, and the side holes are for the chondrocytes to migrate to the injured area, to better repair the cartilage defects.

[0177] The ratios of the bio-inks used in the upper and lower layers of the scaffold structure are as follows:

[0178] Upper layer ink: The upper layer is methacrylic anhydride grafted silk fibroin (SilMA) with a concentration of 15%. The concentration of photosensitizer is 10% v/v, and the concentration of phenol red is 0.8%;

[0179] Lower layer ink: the lower layer is 8M methacrylic anhydride grafted gelatin (GelMA) with a concentration of 15%. The concentration of photosensitizer is 10% v/v and the phenol red concentration is 0.8%. Configuration process:

[0180] The printing process is described using two biomaterials according to the model shown in FIG. 8 as follows: the lower layer scaffold is integrally formed first, and the upper layer scaffold is then integrally formed as an example. The printing process using two biological materials according to the cartilage scaffold model is as follows:

[0181] Image Processing:

[0182] Modeling with C4D software to create a target printing structure, for example, it can be a columnar structure with two layers on top and bottom, as shown in FIG. 8 on both sides of the structure, or three-dimensional construction of different structures, or any of the internal structure can be achieved.

[0183] 2. Separate the upper and lower layers of the model, and export them to the upper structure (upper.stl) and lower structure (bottom.stl) format files, as shown in FIG. 9 and FIG. 10.

[0184] 3. Use software Matlab to read the upper and bottom .stl files.

[0185] 4. Use the Image Processing Toolbox in the software Matlab to segment the images of the upper and bottom 3D models.

[0186] 5. Use the Image BlendingPackage in software Matlab to fuse the two models of upper and bottom, and make the holes correspond.

[0187] 6. Find the central symmetry axis of the upper and bottom models, make a plane containing the symmetry axis, and output the mapping of the 3D model on the plane;

[0188] 7. Rotate the plane in a clockwise direction and cut every certain angle. As shown in FIG. 11, after the cutting process is cycled, the result file after the processing is completed.

[0189] Step 1: Slice the upper and lower layers of the 3D cartilage scaffold model separately, and the graphics of each slice are used as the lighting graphics of the layer; the two bio-inks are respectively loaded into the feeding unit according to the needs of the printed object, and the lower slice is initially projected the bottom of the obtained image is flush with the bottom surface of the resin tank.

[0190] Step 2: The feeding unit 1 with GelMA injects bio-ink GelMA into the resin tank from below the quartz resin tank. The height of the bio-ink is slightly larger than the height of the underlying structure. In fact, the height of the ink is consistent with the height of the formed structure and the volume is consistent or the shape is similar). The stepping motor 1004 drives the reflecting mirrors 10129, 10128, 10127 and the square box 1101 to rotate synchronously, and the projector 1005 and the ink container 110, 2and resin tank are fixed. The reflecting mirror and the rotation centers of square box coincide with resin tank's geometric center 5002. According to the preset angle interval of the image processing system, each time the stepping motor rotates through an angle, it drives the mirror and the square box to rotate by an angle in the same direction. At the same time, the projector quickly switches to the next projected image to complete a projection direction Exposure. After 360° exposure, a specific exposure amount distribution will be formed in the resin tank, and the position with exceeding bio-ink GelMA light curing exposure threshold will be cured and formed, and the remaining positions will still be liquid, and the printing of the underlying structure will be completed. The lens 1003 here is also fixed.

[0191] Step 3: The discharge unit draws away all uncured bio-ink GelMA from the bottom of the resin tank. Then, the supply unit 2 equipped with SilMA injects the bio-ink SilMA into the curing container 11021 from below the quartz resin tank, such as a resin tank. The height of the bio-ink is slightly larger than that corresponding to the resin tank on the top surface of the superstructure. At this time, there is a small amount of overlap between the projection of the upper structure and the upper portion of the lower structure to ensure a stable connection between the upper and lower structures. The stepping motor drives the reflecting mirror and square box to rotate synchronously, and the projector and curing container do not move. The rotation centers of the reflecting mirror and the square box coincide with the geometric center 5002 of the resin tank. According to the preset angle interval of the image processing system, each time the stepping motor rotates through an angle, it drives the reflecting mirror and the square box to rotate by an angle in the same direction. At the same time, the projector quickly switches to the next projected image to complete a projection direction Exposure. After 360° exposure, a specific exposure amount distribution will be formed in the resin tank, and the position exceeding the bio-ink SilMA light curing exposure threshold will be cured and formed, and the remaining positions will still be liquid for printing of the superstructure.

[0192] Step 4: The discharge unit draws all uncured bio-ink SilMA from the bottom of the resin tank. The entire scaffold is printed.

[0193] FIG. 11 is a microstructure diagram of each layer. Among them, it can be seen from the top views of different cavity sizes that the side holes and the top holes are arranged in the same way. At the same time, the fluorescence structure of 400 um was observed under a fluorescence microscope.

[0194] In the absence of any elements and limitations specifically disclosed herein, the invention shown and described herein can be implemented. The terms and expressions are used as illustrative terms and not as limitations, and it is not intended that the use of these terms and expressions exclude any equivalents of the features and parts shown and described or parts thereof, and it should be recognized that each such modifications are possible within the scope of the present invention. Therefore, it should be understood that although the present invention is specifically disclosed through various embodiments and optional features, modifications and variations of the concepts described herein can be adopted by those of ordinary skill workers in the field, and these modifications and variations are considered to fall into the scope of the invention as defined in the appended claims is within the scope of the invention.