WO2024218545A1

WO2024218545A1 - Multi-material optical 3d bioprinter with integrated bioreactor

Info

Publication number: WO2024218545A1
Application number: PCT/IB2023/054077
Authority: WO
Inventors: Linas JONUŠAUSKAS
Original assignee: Uab Vital3D Technologies
Priority date: 2023-04-21
Filing date: 2023-04-21
Publication date: 2024-10-24

Abstract

The proposed invention is a multi-material optical 3D bioprinter with integrated bioreactor that allows selective printing of multiple materials and maintaining the proper atmosphere during the printing process to prevent damage or death of cells encapsulated into the printed structure. The material selection module is designed with a series of vats (1) that house the materials and uses a carousel (6) principle for efficiency and accuracy. The bioreactor module is an enclosed frame that maintains the proper atmosphere and other conditions needed for cells during the printing process. The workflow involves placing all the necessary materials vats (1) into the material exchange module, adjusting the atmosphere inside the bioreactor, and carrying out the printing process by changing materials on-demand. The proposed invention greatly expands the material selection that can be used for printing and allows for the printing of fully functional organs out of different materials and cells selectively placed for maximum bio-functionality.

Description

MULTI-MATERIAL OPTICAL 3D BIOPRINTER WITH INTEGRATED BIOREACTOR

FIELD OF THE INVENTION

The invention relates to the field of bioprinting, in particular to a multi-material optical 3D bioprinter with integrated bioreactor.

DESCRIPTION OF THE RELATED ART

Bioprinting has emerged as a revolutionary technology with great potential to revolutionize the field of regenerative medicine by enabling the creation of functional, living tissues and organs. However, one of the key challenges facing this field is the use of nozzles for material extrusion and injection during printing. This approach not only limits the viscosity of materials that can be used, but it also poses a risk of cell damage during the printing process. Therefore, there is a need for nozzle-free printing methods to advance the field.

Optical 3D printing is a promising technology that can overcome these limitations by using a focused light beam instead of a nozzle for selectivity during printing. This approach offers a greater flexibility in material selection, allowing the use of a wider range of materials with varying viscosities, including biological materials such as living cells and tissues.

Among the various optical 3D printing techniques, stereolithography has emerged as one of the most advanced and widely used. This technique enables the printing of complex 3D structures by using a light-sensitive material that solidifies when exposed to a specific wavelength of light. Stereolithography can be performed using a UV or visible light source, either incoherent or laser, or via multi-photon absorption, which uses a femtosecond laser.

Although stereolithography offers many advantages, such as the ability to use a wide range of materials and high throughput rates, it still has limitations that hinder its applicability to bioprinting. For instance, it can only print one material at a time, making it difficult to create fully functional organs consisting of multiple materials and cell types. Additionally, the printing process can take several hours, making it necessary to maintain optimal environmental conditions throughout the process to ensure the survival and health of the printed cells.

To overcome these limitations, researchers are exploring new approaches that can enable the printing of complex structures with multiple materials and cell types. These approaches include the use of multiple light sources, the development of new light-sensitive materials, and the integration of environmental controls into the printing process.

In summary, while optical 3D printing, particularly stereolithography, offers a promising solution for bioprinting, there is still much work to be done to overcome the restraints of the technology. Therefore, a solution which solves bioprinting limitations is necessary.

The patent document KR102198873B1 (published on 5 January 2021) provides a bio- three-dimensional printer designed to print with multiple biomaterials. The invention is equipped with multiple syringe output module which contains several syringes, each filled with a different biomaterial in fluid form, that can be selectively output according to the output conditions set for each syringe. The printer's rotary shaft drives the syringe holder, which holds the syringes, to rotate to the output position, and the lifting unit controls the elevation of the multiple syringe output module. The invention aims to provide a sealed output environment, and the multiple syringe output module can output different biomaterials at the same time, making it possible to print complex structures. This nozzle based bioprinting technology has inherent limitations regarding the viscosity of materials that can be used, as well as the potential for damaging the cells being printed.

In W02022034042A1 (published on 17 February 2022), a device variant relates to the method of xolography 3D printing that allows for high-speed, high-resolution printing of photopolymerizable polymers, including those containing living cells. The device uses at least one laser generator to emit light beams modulated into at least two light sheets that cross inside a container containing the photopolymerizable polymer. Preferably, the device uses two laser generators, and the light sheets cross at an angle of 90 degrees. The device allows for the efficient production of fully functional tissue surrogates at a high printing speed without compromising cell viability. While it has the potential to produce high-resolution structures, its complex optical setup and use of dual-color photo switchable photo initiators may make it more difficult to use for bioprinting than SLA. Additionally, the use of intersecting light beams in xolography could result in phototoxicity or photobleaching of the biological materials being printed, which could be harmful to living cells and tissues.

An alternative technology of 3D bioprinting is described in patent document Nr. KR102063128B1 (published on 7 January 2020) whereby the method and system for bioprinting a three-dimensional object corresponding to an organ or organoid is provided. The bioprinter is designed to include a sound output unit, a spheroid supply unit, an acoustic control unit, and a photocuring unit. The photocuring unit couples the spheroids by irradiating a laser to the spheroids arranged according to the sound controlled by the sound control unit. Alas, the bioprinter equipped with an acoustic flotation device has limited material compatibility and can only use hydrogels containing a photocuring agent as the fluid for delivering spheroids.

In EP3890945A1 (published on 13 October 2021), invention relates to a method of 3D printing objects using electrophotographic technology. The printing materials are treated with a coating of triboelectrically active material, which can act as a binder and be removed during a heat treatment or sintering step. The materials used can be robust or fugitive, and the latter can be removed in various ways including the application of heat, radiation, or solvents. The invention also includes a multi-material capable EP module that can be included in a 3D printer system with one or more other printer modules, and a single-pass multi-toner EP system that interfaces with a single receiver substrate to transfer toner patterns onto a build plate or a stack of previously transferred printed layers. Although universal, this method of printing is limited in the types of materials that can be used for printing, as it specifically uses engineering ceramic, metal, and polymer materials.

Accordingly, it is desired to provide an improved 3D bioprinter.

This description provides a concept of multi-material optical 3D bioprinter with integrated bioprinter which involves the use of dynamic material selection system in combination with a bioreactor, to bio-print fully functional organs out of different materials/cells selectively placed for maximum bio-functionality. This approach has the potential to greatly improve bioprinting efficiency and expand material selection.

SUMMARY OF THE INVENTION

The proposed invention is a multi-material optical bioprinter with an integrated bioreactor, which expands the capabilities of stereolithography. This 3D bioprinter has three distinct parts: the optical chain, dynamic material selection system, and the bioreactor. The optical chain consists of a light source, shutter, relay optics, power attenuator, and additional optical elements if necessary. The dynamic material selection system is equipped with mechatronic elements that allow the movement of material vats inside the printer during the printing process, enabling the printer to change materials on-demand. The bioreactor is designed to maintain a known and selectively chosen gas atmosphere, temperature, and antibacteria contamination means such as ambient UV light, laminar gas circulation, and more. It houses the Z-axis and is used to move the sample up and down during material selection.

The flexibility of optical 3D printing allows for the separation of the optical chain from the material exchange unit and bioreactor. The bioreactor module is hermetically sealed, allowing for the atmosphere and other conditions needed for cells to be maintained only in the material exchange module and bioreactor, simplifying the requirements for the frame used to house the optical chain as well as its maintenance. The optical chain can be placed freely either underneath or on the side of the material selection and bioreactor modules, with the only requirement being for the light to reach the vats with material for the printing process to occur.

The workflow using the multi-material optical 3D bioprinter is as follows: firstly, all the materials vats are placed into the material change module, then the bioreactor is closed and the atmosphere inside it is changed to one needed for the cells. The printing process is carried out by changing materials on-demand to print the required parts of the organ. When required material is in the position Z axis lovers printing platform into the material and printing process commences. After the procedure is complete, the printed organ is taken out of the bioreactor and processed as dictated by the medical procedures which will follow. With the integration of a bioreactor and material selection system, this multi-material optical bioprinter can revolutionize the field of bioprinting, providing an efficient and effective way of printing functional human organs for transplantation purposes.

BRIEF DESRCIPTION OF DRAWINGS

FIG. 1 : Side view of printing in one of the material vats.

FIG. 2: Material selection view based on vat carousel from the top.

FIG. 3: Material selection based on linear motion of vats from the top.

FIG. 4: Optical chain.

DETAILED DESCRIPTION OF THE INVENTION

The proposed multi-material optical 3D bioprinter with an integrated bioreactor is a highly innovative invention that has the potential to revolutionize the field of bioprinting. Its dynamic material selection system allows for on-demand material changes during printing, which is particularly useful in printing complex biological structures such as organs. The bioreactor module maintains the ideal atmosphere for the cells, including temperature, gas concentrations, and anti-bacterial measures, which are crucial for the development of biological structures. The multi-material optical bioprinter's ability to create complex biological structures could have various applications, such as in the creation of organs for transplants, drug development, and disease modeling. It provides a cost-effective and efficient way to produce structures that could save lives and improve the quality of life for patients worldwide.

Bioprinter uses general optical chain for preliminary light control Fig. 4. This part of the printer is used to deliver precise and controlled amounts of light to vats. To make the proposed invention successfully work the optical chain can be based on one photon or multiphoton polymerization. The difference between them is the light source, in one photon case it is incoherent light source or laser, in multi-photon case - femtosecond laser. After the first component (light source (8)) comes shutter which provides precise control over the exposure of the light. Later the beam is attenuated power vise by power attenuator (10). This is necessary because the light beam can be too powerful for certain applications. Next comes polarization controller (11) which aligns the electric field of the light in a specific direction. Exact polarization requirement is dictated by that beam shaping device (14), but it can be elliptical, circular, or linear with specific orientation. Beam expander (12) follows, which is used to adjust the size of the beam so that it matches the size of the beam shaping element (14) or the matrix size of the device. Ensuring the beam has the correct size is crucial for the beam shaping device (14) to operate correctly. After that comes mirror (13) which redirects light to the beam shaping device (14) that ensures the light is being applied evenly across the entire build area, and to adjust the shape and intensity of the light as needed for optimal printing results. Optical chain ends wits lens (15) and aperture (16) which play important roles in controlling the size, shape, and intensity of the light that is being applied to the vat with material (1). All these components can be separated from the light source or all or some of these elements can be integrated into the system. Such optical chain which controls beam power, polarization and beam size is mandatory and similar for all the beam shaping systems.

The placement of the optical chain module can be flexible, as it can be located either underneath or on the side of the material selection and bioreactor modules. Its primary function is to direct light to the bioreactor module, where the final optical elements for beam directing are situated. Although the optical chain module can be located either inside or outside of the bioreactor, it is preferably placed outside due to the flexibility of optical 3D printing. This configuration allows for the separation of the optical chain from the material exchange unit and bioreactor, maintaining the necessary atmosphere and conditions for cells in the material exchange module and bioreactor only. Consequently, the frame required to house the optical chain is simplified, as is its maintenance.

The dynamic material selection module is a critical component of the printing process, as it contains the necessary materials needed for successfully printing full organs. The module is designed to house material vats (1) and move them inside the printer during printing process. These materials are selected using a carousel principle FIG. 2. Each vat with material (1) is placed on a rotating frame connected to pivot axis (6) with struts (7) and the desired material is rotated to be located on top of the focusing optic (3) and underneath the printing platform (2).

Once the required material is in position, the Z-axis of the printing platform is lowered into the material, and the printing process begins FIG. 1. Inside dynamic material selection module light beam (5) from the optical chain is passed using optical window through bioreactor. Then light beam (5) reflects from mirror (4) on to the focusing optic (3) where the vat with material (1) is placed, and the printing takes place. This process is repeated until the entire structure is printed. After printing, the platform (2) is lifted out of the vat with material (1), and another one is rotated either for printing or development.

While linear vat movement FIG. 3 can be used for dynamic material selection, carousel rotation FIG. 2 is preferred due to its efficiency and accuracy. The carousel principle ensures that each vat is accessible and that the desired material can be located quickly and easily. This results in a more streamlined and efficient printing process, which ultimately leads to a higher quality product.

The proposed invention integrated dynamic material selection system is housed by bioreactor module. The bioreactor is an enclosed frame that is hermetic, allowing for the maintenance of a selectively chosen gas atmosphere and pressure within the printer, and it also ensures the proper temperature achieved with heater and anti-bacterial contamination means, such as ambient UV light and laminar gas circulation. In the bioreactor is located Z-axis and is used to move the print platform up and down. This module addresses the limitations of stereolithography in 3D bioprinting by allowing for the selective printing of multiple materials and maintaining the proper atmosphere during the printing process to prevent damage or death of cells encapsulated into the printed structure. The bioreactor simplifies the requirements for the frame used to house the optical chain, as the atmosphere and other conditions needed for cells are only maintained in the material exchange module and bioreactor. The proposed bioreactor module greatly expands the material selection that can be used for printing and allows for the printing of fully functional organs out of different materials and cells selectively placed for maximum bio-functionality.

The workflow of the invention using a multi-material optical 3D bioprinter is a multi- step process that involves the placement of all the necessary material vats (1) into the dynamic material selection module. The bioreactor is then closed, and the atmosphere inside is adjusted to the specific requirements needed for the cells. When required material is in the position Z axis lovers printing platform into the material and printing process commences The procedure is then carried out by changing materials on-demand to print the required parts of the organ. This allows for the creation of complex, multi-layered structures that are necessary for the successful development of functional organs. Once the printing process is complete, the printed organ is carefully removed from the reactor and processed according to the specific medical procedures that are required for the particular application.

Claims

1. A system for multi-material optical 3D bioprinter with integrated bioreactor, characterized in that, it comprises: a optical chain module to deliver precise and controlled amounts of light to vats; a dynamic material selection module to house material vats and move them inside the printer during printing process; a bioreactor to maintain chosen gas atmosphere, pressure, and temperature ideal for cells within the printer.

2. The system of claim 1, wherein the optical chain can be based either on one-photon absorption using UV or visible light source (incoherent or laser), or multi-photon absorption, realized using femtosecond laser.

3. The system of claim 1, wherein the bioreactor houses material selection module and Z axis with print platform.

4. The system of claim 1, wherein the material vats inside the dynamic material selection system can move during printing process.

5. The system of claim 1, wherein the optical chain module can be either inside or outside of the bioreactor.

6. The system of claim 1, wherein the optical chain module can be placed either underneath or on the side of bioreactor.

7. The system of claim 1, wherein the material vats can be placed on rotating or linear frame.

8. The system of claim 1, wherein the bioreactor additionally has heater element and UV lamp.

9. The system of claim 1, wherein optical chain module directs out light to bioreactor module where final optical elements for beam directing are placed.

10. A method of using multi-material optical 3D bioprinter with integrated bioreactor, characterized in that, it comprises: placing all the material vats into dynamic material selection module; closing bioreactor and changing atmosphere inside it to the one needed for the cells; using Z axis to lover printing platform into the material; changing materials on-demand to print required parts of the organ.