WO2020212134A1

WO2020212134A1 - A structure useful for 3d bioprinting

Info

Publication number: WO2020212134A1
Application number: PCT/EP2020/059114
Authority: WO
Inventors: Duong Nguyen; Adel Itedal NAMRO REDWAN; Hector Martinez; Erik Gatenholm
Original assignee: Cellink Ab
Priority date: 2019-04-16
Filing date: 2020-03-31
Publication date: 2020-10-22

Abstract

The present invention provides for structure (1) comprising a compartment (2) for three-dimensional (3D) bioprinting, a positioning arrangement (3), and a connecting construct (4), which extends between the compartment (2) and the positioning arrangement (3), and also connects the compartment (2) to the positioning arrangement (3), wherein the structure (1) has an axial direction (AD) and a radial direction (RD), wherein the compartment (2) comprises an outside (2a) and an inside (2b), a first surface (5) at said outside (2a), facing mainly away from the positioning arrangement (3), and a second surface (6) in said inside (2b), facing mainly towards the positioning arrangement (3), characterised in that the positioning arrangement (3) has the ability to fix the structure (1) in the axial direction (AD) in relation to, and in close vicinity to, an object (10), e.g. in an opening (11) of the object (10), and that the connecting construct (4) has the ability to fix the structure (1) in the radial direction (RD) in relation to, and in close vicinity to, said object (10), e.g. in the opening (11) of said object (10), that the compartment (2) is connected via the connecting construct (4) such that the first surface (5) and the positioning arrangement (3) are on opposite sides of both the compartment (2), and the connecting construct (4), and that compartment part/s (8), having extension/s from said second surface (6) and mainly towards said positioning arrangement (3), contribute to form the compartment (2); strip; well plate; well plate lid; uses and methods.

Description

A STRUCTURE USEFUL FOR 3D BIOPRINTING

TECHNICAL FIELD

The present invention relates to the field of 3D bioprinting.

BACKGROUND ART

In vitro research aims to minimize the use of live animals; hence, engineering of three- dimensional (3D) tissue models is a fast-growing field with the same goal. Well plates are used in labs worldwide for all cell cultures of animal and human sources to develop models as assay platforms that can substitute the use of animals. The availability and affordability of well plates or well inserts for 3D cell culture is limited and costly. Most are focused on spheroid or organoid cultures and the few that are for larger 3D tissue cultures are few and even more expensive. However, there have been no well plates specifically designed for 3D bioprinting and the culture of 3D bioprinted tissues afterwards. Thus, there is a need to address characteristics and parameters to ease the generation of 3D tissues/constructs with bioprinters.

SUMMARY OF THE INVENTION

The present invention conveys the needs of SD bioprinting in SD bioprinting technology, using bioinks and bioprinters, by providing a structure comprising a compartment for SD bioprinting. Even though 3D bioprinting was introduced for more than a decade, traditional 2D culture well plates are still commonly used for bioprinting, as well as, for culturing the 3D tissue constructs. Hence, today 3D bioprinters are designed to bioprint directly within well plates. Further, embodiments of the structure, according to the present invention, do, besides conveying the needs of 3D bioprinting, also convey the needs of 3D cell culture systems in 3D bioprinting technology by further providing also an efficient culturing of large tissue models.

Further, the present invention relates to a structure comprising a compartment for 3D bioprinting, a positioning arrangement, and a connecting construct, strip comprising the structures, well plates, well plate lids, uses in 3D bioprinting and/or construction of tissue models, methods of 3D bioprinting of a tissue, and method of 3D cell, or 3D tissue, culturing.

A first aspect of the present invention is an optimized structure, comprising a compartment for three-dimensional (3D) bioprinting, wherein the structure enables secure 3D bioprinting within the compartment, while ensuring sufficient abilities for observing, calibrating, and crosslinking during 3D bioprinting. When starting a bioprint, the user will most likely calibrate the bioprinting system to bioprint on a desired surface and at a center point of the desired surface. The structure, in accordance with the present invention, allows for secure 3D bioprinting within the compartment while maintaining sufficient view, and thus enables for any adjustment of bioprinting parameters, as needed on demand, during the secure 3D bioprinting within the compartment. The capacities of allowing for sufficient view during bioprinting, and enabling for any desired adjustment of bioprinting parameters, all during the secure 3D bioprinting within the compartment, are especially important when bioprinting is performed with more than one printhead in which precise calibration, of all three nozzles to the same center of x-, y- and z-axis, is essential. Furthermore, the invention will aid in the automated calibration for each set of well insert, i.e. of a structure, as described herein, and also between sets of well inserts, i.e. of structures, as described herein, for repeat bioprinting.

The secure 3D bioprinting within the compartment is secure, which means that the structure according to the present invention, by comprising, and function of, said positioning arrangement and said connecting construct, respectively, has the ability to be securely fixed in the axial direction in relation to, and in close vicinity to, an object, e.g. in an opening of the object, and the to be securely fixed in the radial direction in relation to, and in close vicinity to, said object, e.g. in the opening of said object. Further, also the compartment part/s and said extension, of the compartment part/s, from said second surface and mainly towards said positioning arrangement, help/s securely fixing the structure, in said axial direction and said radial direction, as well as, contributing to form the compartment.

Further, by using the structure, in accordance with the present invention, 3D constructs do not need to be transferred from another printing surface to the structure, e.g. a well insert. By printing within the structure, in accordance with the present invention, e.g. a well insert, you also have access to support from the inside of the compartment of the structure, e.g. of walls of the inside of the compartment, prior to crosslinking.

Furthermore, in examples of embodiments of the structure, in accordance with the present invention, structure or structures, in accordance with the present invention, e.g. well insert or well inserts, do not reach the bottom of corresponding wells, which brings printed constructs closer to the top of the well and allows for better vision of printing processes.

A second aspect of the present invention is the optimized structure comprising the compartment wherein the compartment also is useful for an effective culture system for 3D tissue models. In addition, the optimized structure, in further embodiments of the present invention, further also allows for air-liquid interface conditions useful for culturing of in vitro models dependent on such conditions.

A third aspect of the present invention is the optimized structure furthermore also providing for an improved handling of samples when changing medium for the culture of the 3D tissue models. The structure, according to the present invention, will furthermore, in still further embodiments of the present invention, also be immobile when any medium change is occurring, hence, that, and the compartment, both lead to decreased disturbance to any samples of the 3D tissue models. In even further embodiments of the present invention, the structure, as described herein, can also be transferred to another well plate as a strip comprising two, or more, of a structure, according to the present invention, hence, this further reduces any sample handling.

Here, the structure, according to the present invention, addresses characteristics and parameters to ease the generation 3D tissues/constructs with most bioprinters. In addition, the structure, according to the present invention, can be translated into other methods of engineering and culturing of 3D engineered tissues/constructs.

Thus, in a first aspect of the present invention, the object above is attained by providing a structure useful in 3D bioprinting, wherein the structure comprising a compartment for 3D bioprinting, a positioning arrangement, and a connecting construct, which extends between the compartment and the positioning arrangement, and also connects the compartment to the positioning arrangement, wherein the structure has an axial direction and a radial direction wherein the compartment comprises an outside and an inside, a first surface at said outside, facing away from the positioning arrangement, and a second surface in said inside, facing towards the positioning arrangement, wherein the positioning arrangement has the ability to fix the structure in the axial direction in relation to, and in close vicinity to, an object, e.g. in an opening of the object, and wherein the connecting construct has the ability to fix the structure in the radial direction in relation to, and in close vicinity to, said object, e.g. in the opening of said object, wherein the compartment is connected via the connecting construct such that the level of the first surface projects away from the positioning arrangement and wherein compartment part/s, having extension/s from said second surface and mainly towards said positioning arrangement, contribute to form the compartment.

Moreover, the present invention further conveys the needs of 3D bioprinting in 3D bioprinting technology, using bioinks and bioprinters, by also providing a structure comprising a platform comprising said first surface at said outside, for 3D bioprinting. Even though 3D bioprinting was introduced for more than a decade, traditional 2D culture well plates are still commonly used for bioprinting, as well as, for culturing the 3D tissue constructs. Hence, today 3D bioprinters are designed to bioprint within well plates. Further, embodiments of the structure according to the present invention do, besides conveying the needs of 3D bioprinting, also convey the needs of 3D cell culture systems in 3D bioprinting technology by further providing also an efficient culturing of large tissue models.

Further, the present invention also relates to a structure comprising a platform comprising said first surface at said outside for 3D bioprinting, an attaching arrangement, and a connecting construct, strip comprising the structures, well plate lids, well plates, uses in 3D bioprinting and/or construction of tissue models, methods of 3D bioprinting of a tissue, and method of 3D cell, or 3D tissue, culturing. A fourth aspect of the present invention is an optimized structure, comprising said platform comprising said first surface at said outside for three-dimensional (3D) bioprinting, wherein the structure enables improved observing, calibrating, and crosslinking during 3D bioprinting. When starting a bioprint, the user will most likely calibrate the bioprinting system to bioprint on a desired surface and at a center point of the desired surface. The structure, in accordance with the present invention, allows for full view during bioprinting, and thus enables for any adjustment of bioprinting parameters, as needed on demand. This capacities of allowing for full view during bioprinting, and enabling for any desired adjustment of bioprinting parameters, are especially important when bioprinting is performed with more than one printhead in which precise calibration, of all three nozzles to the same center of x-, y- and z-axis, is essential. Furthermore, the invention will aid in the automated calibration for each set of well insert, i.e. of a structure, as described herein, and also between sets of well inserts, i.e. of structures, as described herein, for repeat bioprinting.

A fifth aspect of the present invention is the optimized structure further also being invertible and wherein, in an inverted position, the inverted structure defines a compartment useful for an effective culture system for 3D tissue models. In addition, the optimized structure further also allows for air-liquid interface conditions useful for culturing of in vitro models dependent on such conditions.

A sixth aspect of the present invention is the optimized structure furthermore also providing for an improved handling of samples when changing medium for the culture of the 3D tissue models. The structure, according to the present invention, will furthermore also be immobile when any medium change is occurring, hence, leading to decreased disturbance to any samples of the 3D tissue models. The structure, according to the present invention, can also be transferred to another well plate as a strip comprising two, or more, of a structure, according to the present invention, hence, this further reduces any sample handling.

Here, the structure, according to the present invention, addresses characteristics and parameters to ease the generation 3D tissues/constructs with most bioprinters. In addition, the structure, according to the present invention, can be translated into other methods of engineering and culturing of 3D engineered tissues/constructs. Thus, in a fourth aspect of the present invention, the object above is attained by providing a structure useful in 3D bioprinting, wherein the structure comprising a platform for three- dimensional (3D) bioprinting, an attaching arrangement, and a connecting construct, wherein the connecting construct extends between the platform and the attaching arrangement and also connects the platform to the attaching arrangement, wherein the platform has a first surface, facing away from the attaching arrangement, and a second surface, facing towards the attaching arrangement, wherein the attaching arrangement is adapted with attachment means for exterior and releasable attachment of the structure, and wherein the platform is connected via the connecting construct such that the level of the first surface projects away from the attaching arrangement.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 shows a strip (9), according to the present invention, which comprises four structures

(1), also according to the present invention, wherein the structures (1) are connected into a unit. Further, the strip comprises structures (1), and wherein each structure (1) comprises a compartment (2) for three-dimensional (SD) bioprinting. The strip (9), and the structures (1), comprise a positioning arrangement (3) and a connecting construct (4) (here each structure (1) comprises a connecting construct (4). Further, each compartment (2) also comprises, an inside (2b), an outside (2a), a first surface (5) at said outside (2a), and a second surface (6) in said inside (2b). Furthermore, the positioning arrangement/s (3) and the connecting construct/s (4) fix the structure/s (1) in relation to, and in close vicinity to an object, e.g. a well plate (10) e.g. in the opening/s (11). Further, the compartment (2) is connected via the connecting construct (4), and the connecting construct (4), and compartment part/s (8), having extension/s from said second surface (6) and mainly towards said positioning arrangement (3), contribute to form the compartment (2). Furthermore, 3D bioprinting of a tissue (15), or of a tissue construct (15), using the structure (1), and/or the strip (9), is illustrated. Said 3D bioprinting has comprised calibration of the printhead nozzle (28) to the center or desired X-, Y-, Z-axis of a compartment

(2), here of a second surface (6), of a structure (1) or of the strip (9), and extrusion based bioprinting of the cell ladened bioink/s, into the compartment (2) of the structure (1) or, into the compartment (2) of the strip (9), thereby obtaining the tissue (15), or the tissue construct (15). Figure 2 shows a structure (1), according to the present invention, wherein the structure (1) comprises a compartment (2) for three-dimensional (3D) bioprinting. Further, the structure (1) comprises a positioning arrangement (3) and a connecting construct (4). The compartment (2) also comprises, an inside (2b), an outside (2a), a first surface (5) at said outside (2a), and a second surface (6) in said inside (2b). Furthermore, the positioning arrangement/s (3) and the connecting construct/s (4) may fix the structure/s (1) in relation to, and in close vicinity to an object, e.g. an well plate e.g. in the opening/s. Furthermore, 3D bioprinting of a tissue, or of a tissue construct, using the structure (1), may be performed comprising calibration of the printhead nozzle (28) to the center or desired X-, Y-, Z-axis of the compartment (2), here of the second surface (6), of the structure (1).

A strip, i.e. a well insert strip, according to the present invention comprises two, or more, of a structure (1) according to the present invention. The well insert strips, i.e. strips according to the present invention, may be compatible for 24-, 48-, 96-, and 384- well plates, respectively.

Figure 3 shows that the well inserts (1), i.e. the structure/s (1) according to the present invention, are connected to each other to be able to fit columns on a well plate, as well as, here, be attached to a well plate lid (30). Figure 3 further shows a further example that the inserts (1), i.e. the structure/s (1) according to the present invention, and the well insert strips, i.e. strips according to the present invention, are able to be attached to a well plate lid (30) to be used for bioprinting, and are also able to be attached to most well plate lids to be used for bioprinting.

Figure 4 Shows 3D bioprinting on the well inserts (1), i.e. the structure/s (1) according to the present invention. Calibration of the printhead nozzle (28) to the center or desired X-, Y-, Z-axis of the insert (1), i.e. the structure (1) according to the present invention, can be done without hindrance.

Figure 5 Shows the easy observation of the bioprinting process, and the easy observation of the bioprinting process is an advantage of the well insert (1), i.e. the structure/s (1) according to the present invention.

Figure 6 Shows that, once the bioprinting on the well inserts (1), i.e. the structure/s (1) according to the present invention, are completed, the well inserts (1) are securely locked onto the lid (SO) and can be inverted into the wells (11). Figure 6 Shows that the 3D bioprinted constructs (15) remain attached on the well insert (1). Further, the constructs (15) may be inverted, if necessary, into crosslinking solution. Otherwise, the constructs (15) can be submerged into medium.

Figure 7 Shows a well plate (10), i.e. an object (10), having wells (11), i.e. openings (11), that holds the structure/s (1) according to the present invention (and that the well plate (10) holds the strip/s according to the present invention). Each of the structures (1) has a height (h) and a diameter (d), and each well (11) has a well depth (wd) and a diameter (here is no separate reference sign for the diameter of the well disclosed but the diameter of the well coincides here with the diameter (d) of the structure (1)). Moreover, each structure (1), and the strip (9), have axial directions (AD) and radial directions (RD).

Figure 8 Shows that the strips (9), according to the present invention, can be used as individual strips (9) for culturing 3D engineered tissues/constructs (15). Figure 9 Shows that the 3D tissue models (15) are cultured inside the "well" (2) of the well insert (1), i.e. inside the compartment (2) of the structure (1) according to the present invention. If culturing tissue models require air- liquid interface, the "well" (2) of the well insert (1), i.e. the compartment (2) of the structure (1) according to the present invention, may be filled with the desired volume of culture medium.

DEFINITIONS

"Bioprinting" refers to the utilization of 3D printing and 3D printing-like techniques to combine cells, growth factors, and biomaterials to fabricate biomedical parts that maximally imitate natural tissue characteristics. Generally, 3D bioprinting utilizes the layer-by-layer method to deposit materials known as bioinks to create tissue-like structures that are later used in medical and tissue engineering fields. DETAILED DESCRIPTION

The present invention relates to a structure, as described herein, comprising a compartment for three-dimensional (SD) bioprinting, a positioning arrangement, and a connecting construct, which extends between the compartment and the positioning arrangement, and also connects the compartment to the positioning arrangement, wherein the structure has an axial direction and a radial direction, wherein the compartment comprises an outside and an inside, a first surface at said outside, facing away from, e.g. facing mainly away from, the positioning arrangement, and a second surface in said inside, facing towards, e.g. facing mainly towards, the positioning arrangement, wherein the positioning arrangement has the ability to fix the structure in the axial direction in relation to, and in close vicinity to, an object, e.g. in an opening of the object, and wherein the connecting construct has the ability to fix the structure in the radial direction in relation to, and in close vicinity to, said object, e.g. in the opening of said object, wherein the compartment is connected via the connecting construct such that the first surface and the positioning arrangement are on opposite sides of both the compartment, and the connecting construct, and that compartment part/s, having extension/s from said second surface and mainly towards said positioning arrangement, contribute to form the compartment.

Further, the compartment comprises an outside and an inside, wherein said outside means the outside of an enclosed space enclosed by said compartment and wherein said inside means the inside of, and in, said enclosed space enclosed by said compartment.

Furthermore, the compartment is connected via the connecting construct such that the first surface and the positioning arrangement are on opposite sides, in the axial direction, of each other, in relation to both the compartment, and the connecting construct.

Further, that the compartment part/s "have extension/s from said second surface", means that the compartment part/s have said extension/s from the near vicinity of said second surface.

The structure may comprise any suitable material/s known in the art, e.g. any suitable polymer material/s.

The structure, and the compartment, is suitable for 3D bioprinting and may be of any suitable material. For example, the compartment, or any suitable partition of the compartment, may be of any suitable porous material, and may comprise any suitable mesh, or net, configuration.

Further, the compartment may, in embodiments of the present invention, be provided with a porous second surface, and/or the second surface of the compartment may be provided with a mesh, or net, configuration.

Further, the compartment, or any suitable partition of the compartment, may comprise means for allowing permeability, e.g. comprising suitable membrane/s, membrane-like means, any suitable porous material, slits, pores, and/or openings.

The positioning arrangement and said connecting construct have the ability to securely fixing the structure, in accordance with the present invention, in the axial direction in relation to, and in close vicinity to, an object, e.g. in an opening of the object, and in the radial direction in relation to, and in close vicinity to, said object, e.g. in the opening of said object.

Said object, may be part/s of the exterior environment or an exterior object. Further, said object may be a well plate, e.g. any of, for example, 24-, 48-, 96-, and 384- well plate.

The connecting construct, which may comprise one, or several parts, may have any suitable form/s, e.g. elongated form/s, connects the compartment such that the level of the first surface projects away from the positioning arrangement. Further, the connecting construct, ideally in some embodiments, connects the compartment such that the positioning arrangement is elevated from the compartment. Furthermore, the connecting construct, ideally in some embodiments, connects the compartment such that from the positioning arrangement projects the compartment. In still further embodiments of the structure according to the present invention, as described herein, the compartment of the structure comprises means for allowing permeability, for example, the means for allowing permeability is provided on said second surface.

In further embodiments of the structure according to the present invention, as described herein, a structure is disclosed wherein the compartment, or any subsection of the compartment, comprises a porous material.

In even further embodiments of the structure according to the present invention, as described herein, a structure is disclosed wherein the compartment comprises means for enabling an air- liquid interface.

The present invention also relate to a structure, as descried herein, wherein the positioning arrangement is adapted with attachment means for releasable attachment of the structure to an article, wherein the attachment means, for releasable attachment of the structure, e.g., may also be, or are, provided with locking means enabling securely locking of the structure to the article.

In some embodiments the article may be the same as the object.

In further embodiments of the structure according to the present invention, as described herein, a structure is disclosed, comprising attachment means for exterior attachment, for example, to a well plate, or, e.g. to a well plate lid, and, for example, also involving use of, e.g. a ring, or any suitable locking part, to an article, e.g. to a well plate or a well plate lid, for example, to a well plate, or, e.g. to a well plate lid.

In further embodiments of the structure according to the present invention, as described herein, the structure is invertible and wherein, in an inverted position, the inverted structure defines an inverted compartment. In even further embodiments of the structure according to the present invention, as described herein, a structure is disclosed, wherein the structure has a height being 20 mm, or less, and/or a diameter being 22 mm, or less.

In further embodiments of the structure according to the present invention, as described herein, a structure is disclosed, wherein the structure is provided with calibration markings, and/or designs at the compartment, e.g. at the second surface of the compartment, to aid in automated calibration of 3D bioprinters and/or automated dispensing of instruments.

Further embodiments according to the present invention relates to a structure, as described herein, for use within science, medicine, tissue engineering, pharmaceutical therapies, regenerative medicine, stem cell research, and in vitro models.

Further, the present invention does also relate to a strip, wherein the strip comprises two, or more, of a structure, as described herein, wherein all structures are connected into a unit.

The strip, according to the present invention, combining the positioning arrangements and connecting constructs of the, in said strip, comprised structures, has further improved the ability to securely fixing the comprised structures in both the axial and the radial directions in relation to, and in close vicinity to, any object. Further, the strip, according to the present invention, has also improved handling in, and preparations in relation to, 3D bioprinting. Moreover, the strip, according to the present invention, has also simplified production of structures for 3D bioprinting, and handling of the structures in the production of structures for 3D bioprinting.

In further embodiments of the strip according to the present invention, as described herein, the strip comprises two, or more, e.g. 2-32, of a structure, in accordance with the present invention, as described herein.

In still further embodiments of the strip according to the present invention, as described herein, the strip comprises, for example, 2, 3, 4, 6, 8, 10, 12, 16, 24 or 32, e.g. 2, 4, 6, 8, 12, 16 or 24, for example, 2, 3, 4, 6, 8 or 12, e.g. 2, 4, or 6, for example, 2 or 4, e.g. 4, of a structure, in accordance with the present invention, as described herein. Further embodiments according to the present invention relates to a strip, as described herein, for use within science, medicine, tissue engineering, pharmaceutical therapies, regenerative medicine, stem cell research, and in vitro models.

Further, the present invention does also relate to a strip, wherein the strip comprises two, or more, of a structure, as described herein, wherein positioning arrangements, of adjacent structures, are comprised in connection of adjacent structures to each other.

Further, the present invention does also relate to a well plate, wherein the well plate holds one, or more, of a structure, as described herein, and/or one, or more, of a strip, as described herein.

Further embodiments according to the present invention relates to a well plate, as described herein, wherein the well plate holds, for example, 24, 48, 96, or 384 structures.

Still further embodiments according to the present invention relates to a well plate, as described herein, wherein the well plate holds, e.g. 1, 2, 4, 6, 8, 12, 16 or 24, for example, 1, 2, 3, 4, 6, 8 or 12, e.g. 1, 2, 4, or 6, for example, 1, 2, 3 or 4, for example, 1 , e.g. 2, or, e.g. 4, a structure/ structures.

Even further embodiments according to the present invention relates to a well plate, as described herein, wherein the well plate holds, e.g. 1, 2, 4, or 6, for example, 1, 2, 3 or 4, for example, 1 , e.g. 2, or e.g. 4, of a strip/strips, as described herein.

Furthermore, the present invention does also relate to a well plate lid, wherein the well plate lid comprises one, or more, e.g. 1, 2, 4, 6, 8, 12, 16 or 24, for example, 1, 2, 3, 4, 6, 8 or 12, e.g. 1, 2, 4, or 6, for example, 1, 2, 3 or 4, for example, 1 , e.g. 2, or e.g. 4, of a structure, as described herein, and/or one, or more, e.g. 1, 2, 4, or 6, for example, 1, 2, 3 or 4, for example, 1 , e.g. 2, or e.g. 4, of a strip/strips, as described herein, wherein said structure/s and/or said strip/s, is/are releasably attached to said well plate lid. Further, the present invention do also relate to use of a structure, as described herein, or use of a strip, as described herein, in 3D bioprinting and/or construction of tissue models.

Furthermore, the present invention does also relate to a method of culturing 3D cell, or 3D tissue, culture using the structure, as described herein, or the strip, as described herein, comprising the steps of: i) securely fixing the structure, or the strip, in relation to, and in close vicinity to, an object, said securely fixing is achieved by means of the positioning arrangement/s and the connecting construct/s, wherein

the positioning arrangement/s has/have the ability to fix the structure, or the strip, in the axial direction in relation to, and in close vicinity to, an object, e.g. in opening/s of the object, and that the connecting construct/s has/have the ability to fix the structure, or the strip, in the radial direction in relation to, and in close vicinity to, said object, e.g. in the opening/s of said object;

ii) performing an extrusion based bioprinting of a cell ladened bioink/s, into compartment/s of the structure, or of the strip, thereby obtaining a tissue, or a tissue construct, crosslinking of the bioprinted tissue, or the bioprinted tissue construct, to polymerize and/or gelate the tissue, or the tissue construct or, alternatively,

placing 3D cell culture, or 3D tissue culture inside the structure/s either (a) filled with culture medium, or, alternatively, (b) filling with culture medium after placing the culture; and

iii) culturing the bioprinted tissue, the bioprinted tissue construct, the 3D cell culture, or 3D tissue culture.

Moreover, the structure, according to the present invention, and the strip, according to the present invention, may be suitably be used as a tool for researchers investigating 3D in vitro models to facilitate their research because of, e.g. a multi-capacity to improve culture conditions and feasibility. The insert/s, i.e. the structure/s, according to the present invention, and the strip/s, according to the present invention, can be used in well plates for static or dynamic culture.

The well insert/s, i.e. the structure/s, according to the present invention, can have the following parameters:

Height: < 20mm

Diameter: < 22mm

Membrane pore geometry: polygons with 3 or more sides Membrane pore diameter: 0.1 mm or larger

Membrane pore density: 2-50 pores to fit the area of the working surface

The number of wells inserts/s, i.e. the structures, according to the present invention, connected in a strip, according to the present invention, can be, e.g. 3-

32

The dimensions of the well insert, i.e. the structure/s, according to the present invention, may vary depending on the well plate of interest. In general, the height and diameter of the well insert, i.e. the structure/s, according to the present invention, is at least 40% of the well that holds the insert, i.e. the structure, according to the present invention.

In embodiments of the present invention, the height of the well insert, i.e. of the structure/s, according to the present invention, is at least 40% of the well depth of the well, i.e. of the opening, e.g. of a well plate, i.e. the object, that holds the insert, i.e. the structure, according to the present invention.

In further embodiments of the present invention, the height of the well insert, i.e. of the structure/s, according to the present invention, is 40 to 90 %, e.g. 45 to 80 %, e.g. 45 to 70 %, for example 50 to 80 %, for example 50 to 70 %, e.g. 45 to 65 %, or, for example 50 to 65 %, of the well depth of the well, i.e. of the opening, e.g. of a well plate, i.e. the object, that holds the insert, i.e. the structure, according to the present invention.

In still further embodiments of the present invention, the height of the well insert, i.e. of the structure/s, according to the present invention is 90 %, or less, e.g. 80 %, or less, e.g. 70 %, or less, or, for example 65 %, or less, of the well depth of the well, i.e. of the opening, e.g. of a well plate, i.e. the object, that holds the insert, i.e. the structure, according to the present invention.

In further embodiments of the structure according to the present invention, as described herein, a structure is disclosed, wherein the height of the structure, i.e. of the well insert, according to the present invention, is 90 %, or less, e.g. 80 %, or less, e.g. 70 %, or less, or, for example 65 %, or less, of the well depth of the well, i.e. of the opening, e.g. of a well plate, i.e. the object, that holds the structure, i.e. the insert, (i.e. an object to which object the structure may be fixed), according to the present invention.

In even further embodiments of the structure according to the present invention, as described herein, a structure is disclosed, wherein the height of the structure, i.e. of the well insert, according to the present invention, is 40 to 90 %, e.g. 45 to 80 %, e.g. 45 to 70 %, for example 50 to 80 %, for example 50 to 70 %, e.g. 45 to 65 %, or, for example 50 to 65 %, of the well depth of the well, i.e. of the opening, e.g. of a well plate, i.e. the object, that holds the structure, i.e. the insert, (i.e. an object to which object the structure may be fixed), according to the present invention.

Furthermore, with a structure, in accordance with the present invention, comprising a selection of the well depth of the well, i.e. the opening, e.g. of a well plate, i.e. the object, as described herein, and comprising the positioning arrangement and the connecting construct, all in accordance with the present invention, as described herein, have shown to both enable access to support from the inside of the compartment of the structure, e.g. of walls of the inside of the compartment (i.e. of the well insert), prior to, e.g. any crosslinking, and provide that the structure or structures, in accordance with the present invention, e.g. well insert or well inserts, do not reach the bottom of corresponding wells (i.e. openings), which will bring any printed constructs closer to the top of the well and allows for better vision of printing processes. In general, the diameter of the well insert, i.e. the structure/s, according to the present invention, is at least 40% of the well diameter of the well, i.e. of the opening, e.g. of a well plate, i.e. the object, that holds the insert, i.e. the structure, according to the present invention.

The insert, i.e. the structure/s, according to the present invention, may have a base that has pores to allow for infusion of liquids. The pores of a mesh or a net can have different parameters:

Depths (due to thickness of the base) (0.1 - 2.0 mm) Diameter (> 0.01 mm)

Geometry (circles, polygons (triangles, squares, and more)) Density (> 1 pore per cm²)

The well inserts, i.e. the structure/s, according to the present invention, may in a strip, according to the present invention, be connected by a bridge between the well inserts. The strips, according to the present invention, can contain at least two wells, i.e. structures according to the present invention, which can be used in rows or columns in a well plate.

The inserts, i.e. structures according to the present invention, may also be attached, i.e. via the positioning arrangement, to the well plate lid, e.g. with an extra component that fastens the desired size and the number of structures according to the present invention, or strips according to the present invention, to the lid. The fastened well insert strip(s) allows the user to place the lid onto a bioprinter printbed facing up (the insert bases, i.e. platform/s of structure/s according to the present invention, are up) in which the bioprinting is done on the base of the insert, i.e. on the platform of structure according to the present invention. The base of the insert, i.e. the platform of structure according to the present invention, can be used by the bioprinter to recognize the center for automated calibration before bioprinting.

Furthermore, the user is with the structure according to the present invention, able to have a full view of the bioprinting process. Said recognizing of the center for automated calibration before bioprinting, and said enabling to have a full view of the bioprinting process, are allowed by the structure, according to the present invention, wherein, as described herein, the structure comprising a platform for 3D bioprinting, a positioning arrangement, and a connecting construct, which extends between the platform and the positioning arrangement, and also connects the platform to the positioning arrangement, wherein the platform has a first surface, facing away from the positioning arrangement, and a second surface, facing towards the positioning arrangement, the positioning arrangement is exteriorly and releasable attachable, or the positioning arrangement is adapted with attachment means for exteriorly and releasable attachment of the structure, wherein that the platform is connected via the connecting construct such that the level of the first surface projects away from the positioning arrangement.

Even further, the user is with the structure according to the present invention, besides being able to have a full view of the bioprinting process, also provided with setting for effective culturing of 3D tissue samples. Further, the strips according to the present invention, will also be compatible with a range of well plates of different well numbers and geometry.

Moreover, the base, i.e. the platform, of the well insert, i.e. of the structure according to the present invention, may be porous for use as a cell culture insert into common well plates.

Further, the attachment of the well insert, i.e. of the structure according to the present invention, to a well plate lid will allow for easy handling during bioprinting, crosslinking, and culturing.

The present invention also relates to a structure, as described herein, comprising a platform for three-dimensional (3D) bioprinting, an attaching arrangement, and a connecting construct, which extends between the platform and the attaching arrangement, and also connects the platform to the attaching arrangement, wherein the platform has a first surface, facing away from the attaching arrangement, and a second surface, facing towards the attaching arrangement, the attaching arrangement is exteriorly and releasable attachable, or the attaching arrangement is adapted with attachment means for exteriorly and releasable attachment of the structure, wherein the platform is connected via the connecting construct such that the level of the first surface projects away from the attaching arrangement.

The platform is suitable for 3D bioprinting and may be of any suitable material.

For example, the platform, or any suitable partition of the platform, may be of any suitable porous material, and may comprise any suitable mesh, or net, configuration.

Further, the platform may, in embodiments of the present invention, be provided with a porous first surface, and/or the first surface of the platform may be provided with a mesh, or net, configuration.

Further, the platform, or any suitable partition of the platform, may comprise means for allowing permeability, e.g. comprising suitable membrane/s, membrane-like means, any suitable porous material, slits, pores, and/or openings.

The attaching arrangement is stably attachable to the exterior, the exterior environment or an exterior object. For example, with attachment means for exterior attachment, for example involving use of, e.g. a ring, or any suitable locking p, to an object, e.g. to a well plate lid.

The connecting construct, which may comprise one, or several parts, may have any suitable form/s, e.g. elongated form/s, connects the platform such that the level of the first surface projects away from the attaching arrangement. Further, the connecting construct, ideally in some embodiments, connects the platform such that the platform is elevated from the attaching arrangement. Furthermore, the connecting construct, ideally in some embodiments, connects the platform such that the platform projects from the attaching arrangement.

In further embodiments of the structure according to the present invention, as described herein, the structure is invertible and wherein, in an inverted position, the inverted structure defines a compartment wherein the inside of the compartment comprises said second surface of the inverted platform.

In still further embodiments of the structure according to the present invention, as described herein, the platform of the structure comprises means for allowing permeability, for example, the means for allowing permeability is provided on said second surface.

In further embodiments of the structure according to the present invention, as described herein, a structure is disclosed wherein the platform, or any partition of the platform, comprises a porous material.

In even further embodiments of the structure according to the present invention, as described herein, a structure is disclosed wherein the platform comprises means for enabling an air-liquid interface.

In further embodiments of the structure according to the present invention, as described herein, a structure is disclosed wherein the attachment means, for exteriorly and releasable attachment of the structure, are provided with locking means enabling securely locking of the structure in an exteriorly attached position.

In even further embodiments of the structure according to the present invention, as described herein, a structure is disclosed, wherein the structure has a height being 20 mm, or less, and/or a diameter being 22 mm, or less.

In further embodiments of the structure according to the present invention, as described herein, a structure is disclosed, wherein the structure is provided with calibration markings, and/or designs, at the first surface of the platform to aid in automated calibration of 3D bioprinters and/or automated dispensing of instruments.

Further embodiments according to the present invention relates to a structure, as described herein, for use within science, medicine, tissue engineering, pharmaceutical therapies, regenerative medicine, stem cell research, and in vitro models. Further, the present invention do also relate to a strip, wherein the strip comprises two, or more, of a structure, as described herein, wherein all structures are connected into a unit.

Further embodiments according to the present invention relates to a strip, as described herein, for use within science, medicine, tissue engineering, pharmaceutical therapies, regenerative medicine, stem cell research, and in vitro models.

Further, the present invention do also relate to a strip, wherein the strip comprises two, or more, of a structure, as described herein, wherein all structures are connected into a unit.

Further, the present invention do also relate to a well plate lid, wherein the well plate lid comprises one, or more, of a structure, as described herein, and/or one, or more, of a strip, as described herein, being releasably attached to the well plate lid.

Further embodiments according to the present invention relates to a well plate, wherein the well plate holds one, or more, of a structure, as described herein, and/or one, or more, of a strip, as described herein.

Further, the present invention do also relate to use of a structure, as described herein, or use of a strip, as described herein, in 3D bioprinting and/or construction of tissue models. The present invention do also relate to a method of 3D bioprinting of a tissue, or of a tissue construct, using the structure, as described herein, or the strip, as described herein, comprising the steps of: i) mounting, and releasably attach, the structure or the strip to the exterior, e.g. on to a well plate lid;

ii) mixing cells with the bioink/s in order to obtain cell ladened bioink/s;

iii) transferring the, or each of the, obtained cell ladened bioink/s to bioprinting cartridge/s, respectively;

iv) mounting the bioprinting cartridge/s on printhead/s of a 3D bioprinter device; v) inputting bioprinting parameters and calibrate to the first surface of the platform of the structure;

vi) performing extrusion based bioprinting of the cell ladened bioink/s, onto the structure or, onto the structure of the strip, thereby obtaining a tissue, or a tissue construct; and

vii) crosslinking of the bioprinted tissue, or the bioprinted tissue construct, to polymerize and/or gelate the tissue, or the tissue construct, for culturing.

Further, the present invention do also relate to a method of 3D cell, or 3D tissue, culturing using the structure, as described herein, or the strip, as described herein, comprising the steps of: i) securely mounting, e.g. inserting in to well/s of a well plate, i.e. in to the compartment of the structure, or of the strip;

ii) placing 3D cell, or tissue, culture inside the inverted structure/s either (a) filled with culture medium, or, alternatively, (b) filling with culture medium after placing the culture; and

iii) culturing the 3D cell, or 3D tissue, or each of the, obtained cell ladened bioink/s to bioprinting cartridge/s, respectively. Moreover, the structure, according to the present invention, and the strip, according to the present invention, may be suitably be used as a tool for researchers investigating 3D in vitro models to facilitate their research because of, e.g. a multi-capacity to improve culture conditions and feasibility. The insert/s, i.e. the structure/s, according to the present invention, and the strip/s, according to the present invention, can be used in well plates for static or dynamic culture.

Height: < 20mm Diameter: < 22mm

Membrane pore density: 2-50 pores to fit the area of the working surface

The number of wells inserts/s, i.e. the structures, according to the present invention, connected in a strip, according to the present invention, can be, e.g. 3- 32

The dimensions of the well insert, i.e. the structure/s, according to the present invention, may vary depending on the well plate of interest. In general, the height and diameter of the well insert, i.e. the structure/s, according to the present invention, is at least 40% of the well that holds the insert, i.e. the structure, according to the present invention. The insert, i.e. the structure/s, according to the present invention, may have a base that has pores to allow for infusion of liquids. The pores of a mesh or a net can have different parameters:

Depths (due to thickness of the base) (0.1 - 2.0 mm)

Diameter (> 0.01 mm)

Geometry (circles, polygons (triangles, squares, and more))

Density (> 1 pore per cm²) The well inserts, i.e. the structure/s, according to the present invention, may in a strip, according to the present invention, be connected by a bridge between the well inserts. The strips, according to the present invention, can contain at least two wells, i.e. structures according to the present invention, which can be used in rows or columns in a well plate.

The inserts, i.e. structures according to the present invention, may be attached, i.e. via the attaching arrangement, to the well plate lid, e.g. with an extra component that fastens the desired size and the number of structures according to the present invention, or strips according to the present invention, to the lid. The fastened well insert strip(s) allows the user to place the lid onto a bioprinter printbed facing up (the insert bases, i.e. platform/s of structure/s according to the present invention, are up) in which the bioprinting is done on the base of the insert, i.e. on the platform of structure according to the present invention. The base of the insert, i.e. the platform of structure according to the present invention, can be used by the bioprinter to recognize the center for automated calibration before bioprinting. Furthermore, the user is with the structure according to the present invention, able to have a full view of the bioprinting process.

Said recognizing of the center for automated calibration before bioprinting, and said enabling to have a full view of the bioprinting process, are allowed by the structure, according to the present invention, wherein, as described herein, the structure comprising a platform for 3D bioprinting, an attaching arrangement, and a connecting construct, which extends between the platform and the attaching arrangement, and also connects the platform to the attaching arrangement, wherein the platform has a first surface, facing away from the attaching arrangement, and a second surface, facing towards the attaching arrangement, the attaching arrangement is exteriorly and releasable attachable, or the attaching arrangement is adapted with attachment means for exteriorly and releasable attachment of the structure, wherein that the platform is connected via the connecting construct such that the level of the first surface projects away from the attaching arrangement. Even further, the user is with the structure according to the present invention, besides being able to have a full view of the bioprinting process, also provided with setting for effective culturing of 3D tissue samples.

Further, the strips according to the present invention, will also be compatible with a range of well plates of different well numbers and geometry.

Figure 1 discloses a view of a strip (9), according to the present invention, which comprises four structures (1), also according to the present invention, wherein the structures (1) are connected into a unit. Further, figure 1 shows that the strip comprises structures (1), and wherein each structure comprises a compartment (2) for three-dimensional (3D) bioprinting. Further, it is illustrated in figure 1 how 3D bioprinting is performed within the compartment (2)/ compartments (2), i.e. into an inside (2b)/insides (2b) of compartment (2)/compartments (2) of the structure (l)/structures (l)/the strip (9), all according to the present invention. Furthermore, figure 1 shows that the strip, and the structures (1), comprise a positioning arrangement (3) (here each structure (1) comprises a positioning arrangement (3) comprising four positioning arrangement partitions (3) ), and a connecting construct (4) (here each structure (1) comprises a connecting construct (4) comprising four connecting construct partitions (4) ). Connecting construct partitions (4) extend between each compartment (2) and its positioning arrangement partitions (3), respectively, and said connecting construct (4) also connect each compartment (2) to its positioning arrangement (3), respectively. Moreover, each structure (1), and the strip (9), have axial directions (AD) and radial directions (RD). Further, each compartment (2) also comprises, besides said inside (2b), an outside (2a), a first surface (5) at said outside (2a), wherein the first surface (5) faces, in the axial direction (AD), away from the positioning arrangement (3), and a second surface (6) in said inside (2b), wherein the second surface (6) faces, in the axial direction (AD), towards the positioning arrangement (3). Furthermore, figure 1 illustrates how the positioning arrangement/s (3) fix the structure/s (1) in the axial directions (AD) in relation to, and in close vicinity to, an object, e.g. a well plate (10), e.g. in opening/s (11) of the object, e.g. a well plate (10), and that the connecting construct/s (4) fix the structure/s (1) in the radial direction (RD) in relation to, and in close vicinity to, said object, e.g. the well plate (10) e.g. in the opening/s (11) of said object, e.g. of the well plate (10). Further, it is also illustrated in figure 1 that the compartment (2) is connected via the connecting construct (4) such that the first surface (5) and the positioning arrangement (3) are on opposite sides of each other, in relation to both the compartment (2), and the connecting construct (4), in the axial direction (AD), and that compartment part/s (8), having extension/s from said second surface (6) and mainly towards said positioning arrangement (3), contribute to form the compartment (2).

Furthermore, figure 1 illustrates 3D bioprinting of a tissue (15), or of a tissue construct (15), using the structure (1), and/or the strip (9), both according to the present invention. Figure 1 comprises also a 3D bioprinter device (20) with a printhead (25) and a printhead nozzle (28), and said 3D bioprinting has comprised calibration of the printhead nozzle (28) to the center or desired X-, Y-, Z-axis of a compartment (2), here of a second surface (6), of a structure (1) or of the strip (9), and extrusion based bioprinting of the cell ladened bioink/s, into the compartment (2) of the structure (1) or, into the compartment (2) of the strip (9), thereby obtaining the tissue (15), or the tissue construct (15).

Further, from figure 1 it is understood that the strip (9), according to the present invention, and the structure (1), according to the present invention, can also be used for culturing 3D engineered tissues (15)/constructs (15). The 3D tissue models (15) may be cultured inside the compartment (2) of the structure (1) according to the present invention. If culturing tissue models (15) require air-liquid interface, the compartment (2) of the structure (1) according to the present invention, may be filled with the desired volume of culture medium.

Figure 2 discloses a view of a structure (1), according to the present invention, wherein the structure (1) comprises a compartment (2) for three-dimensional (3D) bioprinting. Further, the structure (1) comprises a positioning arrangement (3) and a connecting construct (4). The compartment (2) also comprises, an inside (2b), an outside (2a), a first surface (5) at said outside (2a), and a second surface (6) in said inside (2b). The structure (1) comprises a positioning arrangement (3) comprising four positioning arrangement partitions (3), and a connecting construct (4) comprising four connecting construct partitions (4). Each connecting construct partitions (4) extends between the compartment (2) and its positioning arrangement partition (3), respectively, and said connecting construct (4) also connect the compartment (2) to the positioning arrangement (3). Moreover, the structure (1) has an axial direction (AD) and a radial direction (RD). Said first surface (5) faces, in the axial direction (AD), away from the positioning arrangement (3), and said second surface (6) faces, in the axial direction (AD), towards the positioning arrangement (3). Further, it is also illustrated in figure 2 that the compartment (2) is connected via the connecting construct (4) such that the first surface (5) and the positioning arrangement (3) are on opposite sides of each other, in relation to both the compartment (2), and the connecting construct (4), in the axial direction (AD), and that compartment part/s (8), having extension/s from said second surface (6) and mainly towards said positioning arrangement (3), contribute to form the compartment (2). Further, the height (h) and the diameter (d) of the structure (1) are also shown in figure 2.

Said positioning arrangement/s (3) and the connecting construct/s (4) may fix the structure/s (1) in relation to, and in close vicinity to an object, e.g. a well plate e.g. in the opening/s. Furthermore, figure 2 comprises also a 3D bioprinter device (20) with a printhead (25) and a printhead nozzle (28), and it is understood how 3D bioprinting of a tissue, or of a tissue construct, using the structure (1), may be performed comprising calibration of the printhead nozzle (28) to the center or desired X-, Y-, Z-axis of the compartment (2), here of the second surface (6), of the structure (1).

Figure 3 discloses a view, of a further example, that the well inserts (1), i.e. the structure/s (1) according to the present invention, are connected to each other to be able to be attached to a well plate lid (30), and in accordance with the present invention the well inserts (1), i.e. the structure/s (1), according to the present invention, may also fit columns on a well plate, not shown here.

Further, figure 3 discloses a view of a further example that the inserts (1), i.e. the structure/s (1) according to the present invention, are able to be attached to a well plate lid (30) to be used for bioprinting, and are also able to be attached to most well plate lids (30) to be used for bioprinting.

Figure 4 discloses a view of 3D bioprinting on the well inserts (1), i.e. the structure/s (1) according to the present invention. Calibration of the printhead nozzle (28) to the center or desired X-, Y-, Z-axis of the insert (1), i.e. the structure (1) according to the present invention, can be done without hindrance.

Figure 5 discloses a view showing the easy observation of the bioprinting process, and the easy observation of the bioprinting process is an advantage of the well insert (1), i.e. the structure/s (1) according to the present invention.

Figure 6 discloses that, once the bioprinting on the well inserts (1), i.e. the structure/s (1) according to the present invention, are completed, the well inserts (1) are securely locked onto the lid (30) and can be inverted into the wells (11). Figure 6 discloses that the 3D bioprinted constructs (15) remain attached on the well insert (1). Further, in this further example of the present invention, the constructs (15) may be inverted, if necessary, into crosslinking solution. Otherwise, the constructs (15) can be submerged into medium.

Figure 7 Shows a well plate (10), i.e. an object (10), having wells (11), i.e. openings (11), that holds the structure/s (1) according to the present invention (and that the well plate (10) holds the strip/s according to the present invention). Each of the structures (1) has a height (h) and a diameter (d), and each well (11) has a well depth (wd) and a diameter (here no separate reference sign for the diameter of the well but it coincides here with the diameter (d) of the structure (1)). Moreover, each structure (1), and the strip (9), have axial directions (AD) and radial directions (RD).

Figure 8 discloses that the strips (9), according to the present invention, can be used as individual strips (9) for culturing 3D engineered tissues (15) or for culturing 3D engineered tissues constructs (15). Figure 9 discloses that the 3D tissue models (15) are cultured inside the "well" (2) of the well insert (1), i.e. inside the compartment (2) of the structure (1) according to the present invention. If culturing tissue models require air-liquid interface, the "well" (2) of the well insert (1), i.e. the compartment (2) of the structure (1) according to the present invention may be filled with the desired volume of culture medium.

Claims

1. A structure (1) comprising a compartment (2) for three-dimensional (3D) bioprinting, a positioning arrangement (3), and a connecting construct (4), which extends between the compartment (2) and the positioning arrangement (3), and also connects the compartment (2) to the positioning arrangement (3), wherein the structure (1) has an axial direction (AD) and a radial direction (RD), wherein the compartment (2) comprises an outside (2a) and an inside (2b), a first surface (5) at said outside (2a), facing mainly away from the positioning arrangement (3), and a second surface (6) in said inside (2b), facing mainly towards the positioning arrangement (3), characterised in that the positioning arrangement (3) has the ability to fix the structure (1) in the axial direction (AD) in relation to, and in close vicinity to, an object (10), e.g. in an opening (11) of the object (10), and that the connecting construct (4) has the ability to fix the structure (1) in the radial direction (RD) in relation to, and in close vicinity to, said object (10), e.g. in the opening (11) of said object (10), that the compartment (2) is connected via the connecting construct (4) such that the first surface (5) and the positioning arrangement (3) are on opposite sides of both the compartment (2), and the connecting construct (4), and that compartment part/s (8), having extension/s from said second surface (6) and mainly towards said positioning arrangement (3), contribute to form the compartment (2).

2. A structure (1) according to claim 1, wherein the compartment (2) comprises means for allowing permeability.

3. A structure (1) according to claim 1 or 2, wherein the compartment (2), or any subsection of the compartment (2), comprises a porous material.

4. A structure (1) according to any of claims 1-3, wherein the compartment (2) comprises means for enabling an air-liquid interface.

5. A structure (1) according to any of claims 1-4, wherein the positioning arrangement is adapted with attachment means for releasable attachment of the structure (1) to an article, wherein the attachment means (7), for releasable attachment of the structure (1), e.g., may also be, or are, provided with locking means enabling securely locking of the structure (1) to the article.

6. A structure (1) according to any of claims 1-5, wherein the structure (1) has a height (h) being 20 mm, or less, and/or a diameter (d) being 22 mm, or less.

7. A structure (1) according to any of claims 1-6, wherein the structure (1) has a height (h) wherein the height (h) of the structure (1) is 90 %, or less, e.g. 80 %, or less, e.g. 70 %, or less, or, for example 65 %, or less, of the well depth (wd) of the opening (11) of an object (10) to which object (10) the structure (1) may be fixed.

8. A structure (1) according to any of the previous claims, wherein the structure (1) has a height (h) wherein the height (h) of the structure (1) is 40 to 90 %, e.g. 45 to 80 %, e.g. 45 to 70 %, for example 50 to 80 %, for example 50 to 70 %, e.g. 45 to 65 %, or, for example 50 to 65 %, of the well depth (wd) of the opening (11) of an object (10) to which object (10) the structure (1) may be fixed.

9. A structure (1) according to any of claims 1-8, wherein the structure (1) is provided with calibration markings, and/or designs, at the compartment (2), e.g. to said second surface (6), to aid in automated calibration of 3D bioprinters and/or automated dispensing of instruments.

10. A structure (1) according to any of the previous claims, for use within science, medicine, tissue engineering, pharmaceutical therapies, regenerative medicine, stem cell research, and in vitro models.

11 A strip (9) comprising two, or more, of a structure (1) according to claim 1-10, wherein the structures (1) are connected into a unit.

12. A strip (9) according to claim 9, wherein positioning arrangements (3), of adjacent structures (1), are comprised in connection of adjacent structures (1) to each other.

13. A strip (9) according to claim 12, for use within science, medicine, tissue engineering, pharmaceutical therapies, regenerative medicine, stem cell research, and in vitro models.

14. A well plate (10) wherein the well plate (10) holds one, or more, of a structure/s (1) according to any of the claims 1-10, and/or one, or more, of a strip/s (9) according to any of the claims 11-

13.

15. A well plate lid (30), wherein the well plate lid (30) comprises one, or more, of a structure/s (1) according to any of the claims 1-10, and/or one, or more, of a strip/s (9) according to any of the claims 11-13, wherein said structure/s (1), and/or said strip/s (9), is/are releasably attached to said well plate lid (30).

16. Use of a structure (1) according to any of the claims 1-10, or use of a strip (9) according to any of the claims 11-13, in 3D bioprinting and/or construction of tissue models.

17. Method of 3D bioprinting of a tissue (15), or of a tissue construct (15), using the structure (1) according any of the claims 1-10, or the strip (9) according to any of the claims 11-13, comprising the steps of: i) securely fixing the structure (1), or the strip (9), in relation to, and in close vicinity to, an object (10), said securely fixing is achieved by means of the positioning arrangement/s (3) and the connecting construct/s (4), wherein

the positioning arrangement/s (3) has/have the ability to fix the structure (1), or the strip (9), in the axial direction (AD) in relation to, and in close vicinity to, an object (10), e.g. in opening/s (11) of the object (10), and that the connecting construct/s (4) has/have the ability to fix the structure (1) , or the strip (9), in the radial direction (RD) in relation to, and in close vicinity to, said object (10), e.g. in the opening/s (11) of said object (10);

ii) mixing cells with the bioink/s in order to obtain cell ladened bioink/s;

iii) transferring the, or each of the, obtained cell ladened bioink/s to bioprinting cartridge/s, respectively; iv) mounting the bioprinting cartridge/s on printhead/s (25) of a 3D bioprinter device

(20);

v) inputting bioprinting parameters and calibrate to a compartment (2), e.g. to said second surface (6), of the structure (1) or of the strip (9);

vi) performing extrusion based bioprinting of the cell ladened bioink/s, into the compartment (2) of the structure (1) or, into the compartment (2) of the strip (9), thereby obtaining a tissue (15), or a tissue construct (15); and

vii) crosslinking of the 3D bioprinted tissue (15), or the 3D bioprinted tissue construct (15), to polymerize and/or gelate the 3D tissue (15), orthe 3D tissue construct (15), for culturing.

18. Method of culturing 3D cell, or 3D tissue, culture using the structure (1) according any of the claims 1-10, or the strip (9) according to any of the claims 11-13, comprising the steps of: i) securely fixing the structure (1), or the strip (9), in relation to, and in close vicinity to, an object (10), said securely fixing is achieved by means of the positioning arrangement/s (3) and the connecting construct/s (4), wherein

ii) performing an extrusion based bioprinting of a cell ladened bioink/s, into compartment/s (2) of the structure (1), or of the strip (9), thereby obtaining a tissue (15), or a tissue construct (15), crosslinking of the bioprinted tissue (15), or the bioprinted tissue construct (15), to polymerize and/or gelate the tissue (15), or the tissue construct (15) or, alternatively,

placing 3D cell culture, or 3D tissue culture inside the structure/s (1) either (a) filled with culture medium, or, alternatively, (b) filling with culture medium after placing the culture; and

iii) culturing the bioprinted tissue (15), the bioprinted tissue construct (15), the 3D cell culture, or 3D tissue culture.