MULTI-DIMENSIONAL BIOPRINTING SYSTEM AND METHOD

The present disclosure relates to a container for receiving and supporting extruded biological material during a bioprinting process. The container comprises a reservoir configured to receive a suspension medium, a plurality of walls at least partially defining the reservoir, and a self-scaling port disposed in one or more of the plurality of walls.

TECHNICAL FIELD

The present disclosure relates to multi-dimensional printing, and more particularly, to a multi-dimensional bioprinting system and method.

BACKGROUND

Three-dimensional bioprinting is a process of creating cellular objects by depositing extrudable biological material, also referred to as bio-ink, in a three-dimensional space. Unlike some additive manufacturing techniques, three-dimensional bioprinting involves depositing cellular material in a printer bath (e.g., a petri dish) filled with a suspension material, such as a hydrogel, that allows for more precision and for arranging different cellular materials adjacent to one another to promote cellular growth. Current methods of bioprinting are time consuming, which is detrimental to the short-life of cells, and are also inefficient as the bio-ink must be switched to deposit a different cellular material. Typically, a bioprinter nozzle approaches from one axis (top-down) relative to the printing bath, and deposits material in a cross-sectional layer. To form a structure with two different cellular materials, the bio-ink must be changed (or a first extrusion tip must be removed and a second extrusion tip must be inserted for injecting a second bio-ink) before printing the next layer. While the bioprinter nozzle is not limited to printing from the bottom up, the current methods of bioprinting are limited to approaching the printer bath from one side (from the top) or a single axis.

SUMMARY

A multi-dimensional bioprinting system and method disclosed herein allows for extrusion-based bioprinting from any side of a container containing a suspension medium. According to the method and configuration of the multi-dimensional bioprinting system, bioprinting three-dimensional cellular objects may reduce printing time and allow for multiple extrusions of bio-ink from multiple directions simultaneously. Additionally, the method and system of the present disclosure is more efficient for creating complex structures composed of multiple cellular materials.

In accordance with a first aspect, a container for receiving and supporting extruded biological material during a bioprinting process may include a reservoir configured to receive a suspension medium. A plurality of walls may at least partially define the reservoir, and a self-scaling port may be disposed in one or more of the plurality of walls.

In accordance with a second aspect, a container for receiving a printed biological material may include a reservoir configured to receive a suspension medium. A wall may at least partially define the reservoir, and a self-sealing portion may be integrated in the wall.

In accordance with a third aspect, a method of multi-dimensional bioprinting may include accessing a reservoir of a container through a pierceable portion of the container. The pierceable portion may be integrated into a wall of the container and the wall may at least partially define the reservoir. The method may include extruding a bio-ink into a suspension medium disposed in the reservoir.

In further accordance with any one or more of the foregoing first, second, and third aspects, a container for receiving a printed biological material and/or a method of multi-dimensional bioprinting may further include any one or more of the following aspects.

In one example, the reservoir may be enclosed by the plurality of walls.

In another example, an opening may be in communication with the reservoir.

In some examples, one or more of the plurality of walls may include a rigid material surrounding the self-scaling port or portion.

In other examples, the one or more of the plurality of walls may include a first self-scaling port and a second self-scaling port or portion spaced from the first self-sealing port.

In one example, the self-sealing port or portion may include a high-density foam.

In another example, the self-sealing port or portion may include a high-density rubber

In some examples, a frame may connect the one or more of the plurality of walls.

In another example, the frame may be configured for suspending the container.

In other examples, the plurality of walls may define a prism.

In one example, the container may include a second wall and a second self-scaling portion embedded in the second wall.

In one example, the second wall may at least partially define the reservoir.

In another example, a plurality of walls may define a cube.

In some examples, the container may include an opening in fluid communication with the reservoir.

In some other examples, the container may include a third wall and a third self-sealing portion embedded in the third wall.

In one example, the third wall may at least partially define the reservoir.

In one example, the method may include accessing the reservoir of the container through a second pierceable portion of the container.

In one example, the second pierceable portion may be integrated with a second wall of the container.

In another example, accessing the reservoir may include inserting a first extrusion needle through the pierceable portion of the wall and inserting a second extrusion needle through the second pierceable portion of the second wall.

In some examples, extruding a bio-ink may include extruding a first bio-ink using the first extrusion needle and extruding a second bio-ink using the second extrusion needle.

In some examples, the first bio-ink and the second bio-ink may have different cellular compositions.

Definitions

As used herein, the term “about” means+/−10% of any recited value. As used herein, this term modifies any recited value, range of values, or endpoints of one or more ranges.

As used herein, the terms “top,” “bottom,” “upper,” “lower,” “above,” and “below” are used to provide a relative relationship between structures. The use of these terms does not indicate or require that a particular structure must be located at a particular location in the apparatus.

Other features and advantages of the present disclosure will be apparent from the following detailed description, figures, and claims.

DETAILED DESCRIPTION

A multi-dimensional bioprinting system and method disclosed herein allows for extrusion-based bioprinting into a container and from any side of a container. In a first example, a multi-dimensional bioprinting system10inFIGS.1and2includes a bioprinter14, a container18, and a suspension structure22, which suspends the container18above ground. In the illustrated example, the bioprinter14is disposed beneath the container18and the bioprinter accesses an interior volume26of the container18from below.

The container18is a printer bath and is configured to receive and support extruded or deposited biological material during a bioprinting process. The container18includes an interior volume or reservoir26configured to receive a suspension medium, a plurality of walls30at least partially defining the reservoir26, and a self-sealing port34disposed in one or more of the plurality of walls30. InFIGS.1and2, an extrusion needle38of the bioprinter14is disposed through a self-sealing port34embedded in a bottom wall42of the multi-sided container18. However, the bioprinter14may be arranged to print from any side of the container18through any of the plurality of walls30.

InFIG.3, the container18is cubic and has first, second, third, and fourth sidewalls44,46,48,50, which are perpendicular relative to the bottom wall42and an opening54opposite the bottom wall42. Each sidewall44,46,48,50has a self-scaling port34centrally located and surrounded by a clear rigid material58, together forming a leak-proof pierceable sidewall. The bottom wall42has five spaced out self-scaling ports34integrated with the clear rigid material58to form a leak-proof pierceable bottom wall42. A cubic frame64reinforces the cubic container18and provides support arms68,70at two of the eight corners74of the container18. As shown inFIG.3, the container18contains a suspension medium76.

The rigid material58of the plurality of walls30of the container18may be selected from a range of different materials or combination of materials with varying visibility and material properties. In the illustrated example, the rigid material58is a plastic that may be shaped or molded according to the desired shape or number of self-scaling ports34. The rigid material58is also clear to enhance visibility of the reservoir26of the container18. However, in other examples, the rigid material58surrounding the self-scaling ports34may be opaque or tinted according to the sensitivities and requirements of the bio-ink. The rigid material58can be a metal, glass, ceramic, composite, or a combination of materials.

At each self-scaling port34, an extrusion needle78may be inserted through the container wall30to deposit a bio-ink in the suspension medium. As shown inFIG.3, an extrusion needle78from the bioprinter14is disposed through the self-sealing port34of one of the sidewalls44,46,48,50. The pliable material of the self-scaling port34may allow pivoting to reach a wide range of areas within the reservoir26. Each of the plurality of walls30may have one or more self-scaling port34, and the self-scaling port34may be any shape and size. In some examples, the self-sealing port34may occupy the majority surface area of the wall30. The self-sealing port34may be high-density ethylene-vinyl acetate (EVA) foam, high-density rubber, or silicone with self-healing, self-scaling, and shape memory properties. The self-scaling port34may be pierced multiple times without failure and is configured to sealably close after being pierced.

Turning back toFIGS.1-3, the frame64and suspension structure22are customized for a cubic container18to be suspended above ground. The suspension structure22includes a base board82upon which the bioprinter14sits, a back frame86perpendicular relative to the base board82, and two brackets88,90connecting the back frame86to the connecting arms68,70of the frame64of the container18. The frame64and suspension structure22may be arranged to suspend and support containers of different shapes and to work with bioprinters of various sizes. In the illustrated example, the bioprinter14is movable to access the container18from each side while the container18is held stationary. However, in other examples, the container18may be configured to rotate relative to the bioprinter14. In these examples, the container18may be fixed to a rotatable mount coupled to the base82or the back frame86.

The container18may be any number of three-dimensional shapes. While the container18ofFIGS.1-3is cubic, other example containers may be, for example, spherical, pyramidal, cylindrical, conical, frustoconical, triangular, cuboidal, hexagonal, or another prismatic shape. For example, inFIG.4, a spherical container118includes a single spherical wall130and an opening154at a top portion of the container118. A plurality of self-scaling ports134or portions are integrated with the wall130of the container118and are circumferentially spaced about a central axis A of the container18. The self-scaling ports134are oblong and are spaced about 90 degrees relative to each other. However, in other examples, the self-sealing ports may be circular, rectangular, or other polygonal shape spaced about less than or more than 90 degrees relative to the other ports.

Other example containers have two or more walls and may be partially or completely enclosed (i.e., no opening to atmosphere).FIGS.5-7illustrate other example containers218,318,418that are different shapes. For example, inFIG.5, a cylindrical container218includes a cylindrical wall230, a bottom wall242, and an opening254opposite the bottom wall242. The cylindrical wall230is perpendicular relative to the bottom wall242, and includes a plurality of circular, circumferentially disposed self-sealing ports234. The bottom wall242includes a plurality of spaced apart self-scaling ports234. InFIG.6, the container318is frustoconical with an angled wall330that tapers toward an opening354. The container318has a plurality of self-scaling portions334that span a large portion of the surface area. The self-scaling portion334of the bottom wall342, for example, has a larger surface area than the rigid material358adjacent to the self-sealing portion334. In some bioprinting applications, an anaerobic container may be desirable for printing biological material. In this case, the container may be completely enclosed on all sides, such as, for example, the container418ofFIG.7. In this example, the container418is prismatic with the majority of the surface area of the walls430being a self-scaling portion434.

A suspension medium or material76ofFIG.3is a synthetic or natural medium compatible with biological materials and supports bioprinted material in a three-dimensional space. The suspension material76may contain elements that support and promote the growth of the biomaterials. In some examples, the suspension material76may be a gel, such as a hydrogel, used for three-dimensional bioprinting applications. The suspension material76is self-healing such that the suspension material76allows for insertion of an injection needle78, and then occupies the space of the needle when it is removed from the suspension material76.

The term “bio-ink” as used herein may refer to any biological material suitable for bioprinting. For example, the material may be any biological material such as cells or biological polymers that can be printed using a printing device to create a biological structure.

FIG.8is a diagram of an example method800or process of multi-dimensionally bioprinting using a sealed, yet penetrable, container18containing a suspension medium76. The method800may be performed using any of the containers18illustrated inFIGS.1-3or the containers illustrated inFIGS.4-7. For case of reference, the method800is described with reference to the container18ofFIGS.1-3. Initially, the bioprinting process800may involve or use a computer, three-dimensional modeling software (e.g., Computer Aided Design, or CAD, software), bioprinter14, and bio-ink. Once a CAD model is produced, the bioprinter14may read data from the CAD file and extrude or print various deposits bio-ink to fabricate a three-dimensional biological object according to the CAD file.

The method800includes a step804of accessing a reservoir26of a container18through a pierceable portion34of the container18, such as through the self-scaling port34that is integrated into a wall30of the container18, as shown inFIGS.1-2. Accessing the reservoir includes inserting an extrusion needle78of a bioprinter14through the self-scaling port34so that the distal tip is disposed in the reservoir26of the container18. Once the extrusion needle78is in a desired printing location, the method800includes a step808of extruding a bio-ink into the suspension medium76disposed in the reservoir26of the container18. The method800may further include accessing the reservoir26of the container through a second pierceable portion of the container, such as through the self-sealing port34of the container18shown inFIG.3.

In some examples, accessing the reservoir26includes inserting a first extrusion needle78through the pierceable portion34of the wall30, and inserting a second extrusion needle78through the second pierceable portion34of the second wall. The step of extruding a bio-ink may include dispensing or extruding a first bio-ink through the first extrusion needle78, and dispensing or extruding a second bio-ink using the second extrusion needle78. The first and second extrusion needles78may be inserted simultaneously or consecutively, and the first bio-ink and the second bio-ink may have different cellular compositions. However, in other examples, the same extrusion needle78may be used to access the reservoir from different locations of the container18and for depositing different bio-inks. By accessing the reservoir26through different sides or walls30of the container18, the biological object may be printed progressively according to a cellular structure, for example, rather than layer by layer from the bottom up.

Cell growth is directional and time dependent, and some biological structures require printing multiple types of cells in various arrangements and specific orders to encourage cellular bonding and growth. In one example method of the present disclosure, a bioprinter is programmed to print a cardiovascular system progressively by cellular structure. A first bio-ink composed of endothelial cells may be deposited first through an extrusion needle to form the inner lining of the vascular system. The entire endothelial structure may be printed, leaving voids for other cellular structures, before switching or using a second bio-ink. A second bio-ink composed of vascular cells may then be extruded into voids and/or around the endothelial structure. Because the bioprinter14can access the container18multi-dimensionally, the vascular cells of the second bio-ink may be placed adjacent to the endothelial cells in locations that could not be accessed from one side (i.e., the opening) of the container18without piercing the already printed endothelial structure. A third bio-ink composed of muscular tissue cells may then be printed into voids and/or around the vascular structure and/or endothelial structure.

The multi-dimensional bioprinting method500and containers18,118,218,318,418disclosed herein allow for efficient and logical multi-dimensional bioprinting, and may provide considerable benefits over current methods of three-dimensional bioprinting. The disclosed bioprinting containers18,118,218,318,418are simply constructed, and allows unconstrained multi-dimensional access for the bioprinter. Conventional methods of bioprinting require printing a biological structure from the bottom of the printer bath working up, printing in layers or cross-sections of the structure. When the biological structure includes more than one bio-ink per layer, each layer must be constructed at a time because forming or leaving voids and filling those voids in later around the first printed structure with a second bio-ink could not be done without piercing or rupturing the already printed tissue. Thus, printing layer-by-layer is arduous and time consuming, and often requires multiple printer nozzles or frequent changes of the bio-ink. By comparison, the bioprinting method of the present disclosure enables printing of an entire first structure of a first bio-ink before printing a second structure of a different bio-ink.

While this specification contains many specific implementation details, these should not be construed as limitations on the scope of any invention or of what may be claimed, but rather as descriptions of features that may be specific to particular examples of particular inventions. Certain features that are described in this specification in the context of separate examples can also be implemented in combination in a single example. Conversely, various features that are described in the context of a single example can also be implemented in multiple examples separately, or in any suitable subcombination. Moreover, although features may be described herein as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination can in some cases be excised from the combination, and the claimed combination may be directed to a subcombination or variation of a subcombination.