Cell transport device

Abstract

The present invention relates to a device (1; 10; 15) for the storage and / or transport of cells, in particular cell aggregates, comprising at least one chamber (2) having a base (5; 11) and a top (6; 12), the top (6; 12) being located opposite the base (5; 11), the base (5; 11) being formed by a substrate comprising at least one recess (7) for collecting a fluid, wherein the distance (8) between the base (5; 11) and the top (6; 12) of at least one chamber (2) is less than the width (9) of at least one recess (7), and the width (9) of at least one recess (7) is the smallest line segment between two opposite points passing through the center of the base region of at least one recess (7).

Description

[Technical Field]

[0001] The present invention relates to a device for the storage and / or transport of cells. [Background technology]

[0002] The handling, cultivation, and analysis of live cell cultures are commonly used methods in biomedical research and development and the pharmaceutical industry. Primary cell cultures and continuous cell lines are widely used for virus cultivation, biopharmaceutical production, efficacy studies, and toxicity testing. For example, U.S. Patent Application Publication No. 2020 / 095526(A1) discloses the cultivation and analysis of cells in the form of spheroids using a microfluidic array. The same device is also described in International Publication No. 2022 / 086926 and Eilenberger et al., 2021, Advanced Science, 8, 11, pp. 2198-3844. Thus, cell cultures are used worldwide by scientists who require a wide variety of cells depending on their research topic. To meet the increasing demand for live cell cultures, cells are shipped from cell banks to research and production facilities around the world. However, transporting live cells is challenging because cell viability must be maintained during shipping. Another important aspect of cell transportation is the high cost. For example, the second largest cell bank in Germany (Cell Line Service; CLS) spends 40,000-50,000 euros annually for cell delivery, a cost that depends primarily on the type of shipment and the customs regulations of the receiving country (e.g., EU or non-EU).

[0003] Currently, two delivery options are commonly used, which involve shipping live cells or shipping frozen cells on dry ice.

[0004] When shipping live cells, the cells are transported under thawed conditions in cell culture flasks. Different flask sizes can be selected depending on the cell type and shipping time. A standard flask size for shipping is, for example, a 25 cm flask with a medium volume of approximately 20-70 mL.2 or 75cm 2 The flask has a surface area (relative to the growth surface) of 1000 μm. During transportation, cells remain viable and have the ability to divide. The conditions for live cells during transportation are significantly different from optimal cell culture conditions, such as an appropriate temperature of 37°C, optimal CO2 supply, and an appropriate amount of medium, which limits cell growth behavior during transportation.

[0005] Cultured cells can also be shipped using dry ice (a solid form of carbon dioxide), which keeps the cells frozen at -80°C. However, shipping dry ice is expensive, bulky, and dangerous, and many shipping companies refuse to handle it. Furthermore, if the dry ice evaporates before the shipment reaches its destination, cells can be crushed, and cell recovery is compromised because the cryoprotectant required for cryogenic storage is toxic to cells at ambient temperatures. Therefore, dry ice must be handled carefully, and prescribed safety precautions must be implemented. It has been found that the viability of cells shipped on dry ice often drops by up to 30% upon arrival at the recipient. Different success rates regarding growth behavior between adherent and suspension cultures in the recipient laboratory can also be observed.

[0006] It is therefore an object of the present invention to provide means and methods for enhancing and facilitating the transport of cells and cell aggregates. Summary of the Invention

[0007] Thus, the present invention relates to a device for storing and / or transporting cells, particularly cell aggregates, comprising at least one chamber having a base and a top, the top being located opposite the base, the base being formed by a substrate comprising at least one recess for collecting a fluid, the distance between the base and the top of the at least one chamber being less than the width of the at least one recess, the width of the at least one recess being the smallest line segment between two opposing points passing through the center of the base region of the at least one recess. Surprisingly, it has been found that the present invention exhibits excellent capabilities for transporting and / or storing cells, particularly cells as cell aggregates. Cells and cell aggregates can safely reside in at least one recess of the device of the present invention. Thus, using the device according to the present invention, it is possible to transport and / or store cells and cell aggregates in a reliable, compact, and cost-effective manner. Transporting and / or storing cells in the form of aggregates is even more advantageous, since aggregated cells require limited space for storage and / or transport due to their compact form and exhibit enhanced resistance to harmful effects. Furthermore, cell aggregates typically have a size larger than, for example, the dimensions of the chambers of a microfluidic device, so that the cell aggregates cannot migrate from the recesses. The cell aggregates remain in one or more recesses of the device of the present invention even under severe vibration and shock during storage and / or transportation. This is particularly advantageous since live cells are typically sensitive to such vibration and shock.

[0008] The size (e.g., diameter) of the cell aggregates can be limited by the width of at least one recess. For example, the size of the cell aggregates is limited by the width of the recess, and the height of the chamber is less than the width of the recess. Thus, the cell aggregates are larger than the height of the chamber and cannot move into the chamber due to geometric constraints.

[0009] Furthermore, due to the limited volume of the devices of the present invention, less fluid is required to store and / or transport the cell aggregates. For example, the cell aggregates can be delivered at a significantly lower cost compared to current delivery methods due to the limited fluid volume required and reduced packaging weight.

[0010] Another aspect of the present invention is a method for the storage and / or transport of cells, in particular cell aggregates, comprising the steps of: a) applying a fluid containing cells to at least one chamber of a device as defined herein, thereby providing said fluid in at least one recess; b) incubating the cells until at least one aggregate is formed in the at least one well.

[0011] It has been found that the method of the present invention allows for efficient storage and / or transport of cell aggregates. Cell aggregates can be formed by simply adding a fluid containing individual cells into at least one chamber, particularly into at least one recess of the device of the present invention. After formation, the cell aggregates are prevented from being washed out of the at least one recess due to the low height of the chamber compared to the width of the recess. This feature has the advantageous effect that a) after applying the cell-containing fluid into the at least one chamber, the individual cells settle in the at least one recess, and b) the cell aggregates present in the at least one recess are safely formed.

[0012] A further aspect of the present invention relates to the use of a device as defined herein for the storage and / or transport of cells, in particular cell aggregates.

[0013] Yet another aspect of the present invention is a method for screening the effect of a compound on cellular aggregates, comprising the steps of: a) providing a solution containing cells; b) applying the solution of step a) to at least one chamber of a device as defined herein, thereby providing said fluid in at least one recess; c) incubating the cells until at least one cell aggregate is formed in at least one well; d) treating at least one cell aggregate with at least one compound; d) measuring the effect of said at least one compound on said at least one cell aggregate.

[0014] In particular, the method is useful in the fields of biomedical research, drug screening, and personalized medicine. For example, the physiological state of a patient can be profiled according to the present invention to identify preclinical stages of disease and to make appropriate differential diagnoses. [Brief explanation of the drawings]

[0015] [Figure 1a] 1 shows a schematic top view of an embodiment of a device according to the invention; [Figure 1b] 1b shows a cross-sectional side view of an embodiment of a device according to FIG. 1a having a hemispherical recess and a frustoconical hollow body. [Figure 1c] 1b shows a cross-sectional side view of an embodiment of a device according to FIG. 1a, including a fluid chamber and a hemispherical recess with a frusto-conical hollow body. [Figure 2a] 1 shows a schematic plan view of an embodiment of a device according to the invention; [Figure 2b] 2b shows a cross-sectional side view of an embodiment of a microfluidic device according to FIG. 2a having a hemispherical recess and a frusto-conical hollow body. [Figure 2c] 2b shows a cross-sectional side view of an embodiment of a device according to FIG. 2a, including a fluid chamber and a hemispherical recess with a frustoconical hollow body. [Figure 3a] 1 shows a schematic plan view of another embodiment of a device according to the invention; [Figure 3b] 3b shows a cross-sectional side view of an embodiment of a device according to FIG. 3a, including a fluid chamber, a hemispherical recess, and a frusto-conical hollow body. [Figure 4a] 2b shows a schematic plan view of an embodiment of the base of the device according to FIG. 2a. [Figure 4b] 3b shows a schematic plan view of an embodiment of the base of the device according to FIG. 3a. [Figure 5a] 2b shows a schematic top view and a schematic side view of the upper layer of an embodiment of a microfluidic device according to FIG. 2a. [Figure 5b] 2b shows a schematic top view and a schematic side view of the upper layer of an embodiment of a microfluidic device according to FIG. 2a. [Figure 6] 1 shows a schematic workflow of a method according to the invention for the storage and / or transport of cells, in particular cell aggregates. [Figure 7] 1 shows a schematic workflow of a method according to the present invention for screening compounds on cell aggregates. [Figure 8a] Schematic diagrams of different chamber heights (50 μm, 100 μm, 150 μm) at constant recess width are shown. [Figure 8b] 1 shows flow profiles of a microfluidic flow in a chamber of a device according to the invention at different chamber heights. [Figure 9a] Schematic diagrams of different hollow body widths (500 μm, 600 μm, 700 μm, 800 μm, 9000 μm) at a constant width of the recess (500 μm) are shown. [Figure 9b] 10 shows the flow profile of a microfluidic flow in the chamber of a device according to the invention for different hollow body widths. [Figure 10] Figure 1 shows cell viability of cell aggregates after overnight storage at 37°C and room temperature (RT) in a device according to the invention. [Figure 11] 1 shows fluorescence micrographs of cells harvested from a device according to the invention when seeded onto a cell culture plate. Cells were applied to the device at six different densities. [Figure 12] Cell viability of cells after 3 days of storage at −196° C. in various concentrations of cryopreservation medium is shown. DETAILED DESCRIPTION OF THE INVENTION

[0016] As used herein, "cell" refers to a membrane-enclosed particle that may contain proteins, nucleic acids, lipids, metabolites, and / or organelles. Cells can proliferate and / or divide into or release other cells. According to another preferred embodiment of the present invention, the cells are selected from the group consisting of eukaryotic cells, prokaryotic cells, extracellular vesicles, and combinations thereof. In particular, the eukaryotic cells may be mammalian cells, preferably epithelial cells, nerve cells, muscle cells, connective tissue cells, stem cells, and preferably tumor cells. The prokaryotic cells may be bacterial or archaeal cells. In particular, the extracellular vesicles may be exosomes, microvesicles, or apoptotic bodies. The cells according to the present invention may have a size of 80 nm to 100 μm, preferably 90 nm to 80 μm, and more preferably 100 nm to 60 μm.

[0017] The term "cell aggregate" refers to a three-dimensional micromass of individual cells suspended in a fluid. Cell aggregates according to the present invention are formed by cell aggregation. Individual cells can stick, bond, adhere, or connect to each other to form aggregates. Individual cells can also fuse together to form cell aggregates. Aggregates may have a size of 60 μm to 3 mm, preferably 80 μm to 2 mm, and preferably 100 μm to 1 mm. Cell aggregation can be a reversible or irreversible process.

[0018] The "size" of a cell can be determined by methods known in the art (eg, electron microscopy).

[0019] During the aggregation process, cell aggregates may grow in size and settle. The reverse process, in which cell aggregates are redispersed as individual cells, rarely occurs spontaneously but can occur under mechanical and / or chemical disaggregation. Cell aggregates, particularly those composed of eukaryotic cells, are three-dimensional cell micromasses with spheroid or spheroid-like morphology. Such spheroids can also be considered "organoids." "Cell spheroids" can be formed by eukaryotic cells, particularly mammalian cells (e.g., human cells), with particularly preferred cells being those present in mammalian organs and tissues. These spheroids may contain one or more types of cells. The use of different types of cells allows for the production of more complex "organoids" or tissue-like structures. Cell aggregates can also be three-dimensional micromasses of extracellular vesicles, or a combination of eukaryotic or prokaryotic cells and extracellular vesicles with spheroid-like morphology.

[0020] As used herein, "base" refers to the inner bottom surface of at least one chamber, located substantially below the fluid introduced into the chamber and parallel to the direction of fluid flow. As used herein, "top" refers to the inner top surface of at least one chamber, located opposite the inner bottom surface. As used herein, "base region" refers to the two-dimensional intersecting region of a three-dimensional geometric body. Preferably, the base region of at least one recess has a circular or elliptical shape.

[0021] The cells and / or cell aggregates according to the present invention can be stored and / or transported in a fluid. The fluid can be introduced into at least one chamber of the device of the present invention through at least one opening. As used herein, "fluid" refers to a liquid fluid.

[0022] According to another preferred embodiment of the present invention, the base of at least one chamber further comprises a hollow body, the hollow body being fluidly connected to at least one recess and the interior of at least one chamber, the width of the base region of the hollow body being at least partially the width of at least one recess. In particular, the hollow body is located between at least one recess and the interior of at least one chamber, with at least one recess located below the hollow body and the interior of at least one chamber located above the hollow body. The hollow body of the present invention has the advantage that applied individual cells are properly captured in each recess of the device of the present invention. Surprisingly, it has been found that the hollow body of the present invention promotes cell aggregation, since cells can automatically fall into the recess by gravity and do not remain in the chamber. Therefore, cell aggregation in at least one recess can be effectively increased by the presence of the hollow body of the present invention. Another advantage relates to increased fluid supply to cell aggregates in at least one recess. It has been found that by introducing a hollow body positioned between at least one recess and the interior of at least one chamber, more fluid can be collected in at least one recess, allowing for a continuous supply of fluid to the cell aggregates. The at least one chamber, at least one hollow body, and at least one recess are fluidically connected, allowing fluid to flow through the chamber and fill the hollow body and recess where the cell aggregates reside. As described above, the device of the present invention may be exposed to severe vibrations and shocks and is often tilted during storage and / or transportation. In particular, tilting the device of the present invention causes fluid flow within at least one chamber. The presence of the hollow body ensures enhanced fluid flow within the recess, resulting in better fluid supply of the cell aggregates with nutrients and improved cell capture, as shown in the examples. Therefore, the cell aggregates can be uniformly supplied with fluid during storage and / or transportation while simultaneously safely residing within the recess of the device of the present invention. The fluid supply of the cell aggregates within at least one recess can also be altered by the shape and / or width of the hollow body.

[0023] As used herein, the "base region of the hollow body" refers to the two-dimensional intersecting region of the three-dimensional hollow body that contacts the base region of at least one recess and is located opposite the base of at least one chamber. Preferably, the base region of the hollow body has a circular or elliptical shape. The width of the base region of the hollow body is at least partially equal to the width of at least one recess.

[0024] As used herein, "top region of hollow body" refers to the two-dimensional intersecting region of the three-dimensional hollow body that contacts the base of at least one chamber and is located opposite the base region of at least one recess.

[0025] According to another preferred embodiment of the present invention, the width of the top region of the hollow body is 500 μm to 3 mm, preferably 1 mm to 2 mm, and the width of the hollow body is the smallest line segment between two opposite points passing through the center of the top region of at least one recess. The width of the hollow body can be adapted to improve fluid flow and cell capture into at least one recess.

[0026] According to another preferred embodiment of the invention, the hollow body has the shape of a truncated cone, the base and top regions of the truncated cone having the shape of a circle or an ellipse.

[0027] To avoid loss or washout of cell aggregates from at least one recess of the present invention during storage and / or transportation, the distance between the base and top of the at least one chamber is less than the width of the at least one recess. Due to this geometric limitation, cell aggregates are prevented from escaping from at least one recess of the present invention and remain within the recess. The height of the at least one chamber can be adapted to the width of the at least one recess. According to another preferred embodiment of the present invention, the ratio of the distance between the base and top of the at least one chamber to the width of the at least one recess is 0.5:1 to 0.01:1, preferably 0.2:1 to 0.02:1, and preferably 0.1:1 to 0.04:1.

[0028] According to another preferred embodiment of the present invention, the substrate comprises, consists of or is coated with a biocompatible material.

[0029] According to another preferred embodiment of the present invention, the biocompatible material is silicone or a plastic material or glass. Glass is optically transparent, electrically insulating, and chemically inert. Silicon is optically transparent, oxygen permeable, inexpensive, and resistant to organic solvents. Plastic-based devices are also very important for industrial applications. The wide variety of plastic materials offers great flexibility in selecting an appropriate material with specific properties. Compared to inorganic materials, polymers are readily available and inexpensive, making them commonly used materials for devices suitable for cell storage and / or transport. Preferably, the biocompatible material is a plastic material. Processes for manufacturing and / or molding plastic substrates are known in technologies such as injection molding or 3D printing.

[0030] According to another preferred embodiment of the present invention, the biocompatible material is selected from the group consisting of polystyrene, cycloolefin copolymer, polymethyl methacrylate, cycloolefin polymer, polydimethylsiloxane, polycarbonate (PC), polypropylene (PP), polyvinyl chloride (PVC), perfluoropolyether (PFPE), polyurethane, poly(ethylene terephthalate) (PET), polyester, and thiol-ene. Preferably, the biomaterial is suitable for use at temperatures ranging from -196 to 121°C and is resistant to repeated temperature changes. The biocompatible material of the device of the present invention is also capable of withstanding sterilization procedures known in the art, such as gamma irradiation, steam sterilization, or ethylene oxide sterilization.

[0031] According to another preferred embodiment of the invention, at least one recess and / or the substrate is at least partially coated with an anti-adhesion layer. The anti-fouling layer prevents adhesion of cells and proteins on the surface of at least one recess. In another preferred embodiment of the device according to the invention, at least one chamber is also at least partially coated with an anti-fouling layer.

[0032] According to another preferred embodiment of the present invention, the anti-adhesion layer is selected from the group consisting of polyethylene glycol (PEG) based polymers, preferably PLL-g-PEG or PEGS, with different lengths varying from about 22 to 450 repeating units and / or corresponding to molecular weights in the range of 1000 to 20000 Da, polybetaines, such as poly(sulfobetaine) (PSB) or poly(carboxybetaine) (PCB), polyampholytes, fluorinated polymers, polysaccharides, such as agar or agarose, polyhydroxypolymers, such as poly(2-hydroxyethyl methacrylate (poly-HEMA) or poly-hydroxypropyl methacrylate (poly-HPMA), poly(ethylene oxide), hydroxypropyl methylcellulose (HPMC), poly(vinyl alcohol) (PVA), poly(2-hydroxyethyl methacrylate ... The antifouling nanointerfaces are selected from the group consisting of materials such as poly(hydroxyethyl methacrylate) (pHEMA), poly(acrylic acid) (PAA), dextran, hydroxyethyl cellulose (HEC), natural biopolymers (hydrophobins, S-layer protein SbpA), antifouling nanointerfaces such as polyelectrolyte multilayers (PEMs), self-assembled monolayers (SAMs), non-ionic surfactants such as polyoxyethylene dodecanol, Tween-20, n-dodecyl-D-maltoside (DDM) and Pluronic (triblock copolymer PEO-b-poly(propylene oxide)-b-PEO), and silanes such as 3-glycidoxypropyltrimethoxysilane (GPTMS), 3-chloropropyltrichlorosilane (CPTMS), and (3-aminopropyl)triethoxysilane (APTES).

[0033] According to another preferred embodiment of the invention, at least one recess has the shape of an elliptical paraboloid or a hemisphere.

[0034] According to another preferred embodiment of the present invention, at least one recess having the shape of an elliptical paraboloid is provided, wherein at least a portion of the shell surface of the paraboloid is rotated in space according to the equation y=A*x B where A is 1 to 10, preferably 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10, and B is 2, 4, or 6. When at least one recess having the shape of an elliptical paraboloid or a hemisphere is used according to the above configuration, a single round cell aggregate can be formed in the at least one recess.

[0035] According to another preferred embodiment of the present invention, the at least one recess has a width of 100 μm to 3 mm, preferably 200 μm to 2 mm, more preferably 500 μm to 1.5 mm.

[0036] 1a-1c show schematic plan views of an embodiment of a device 1 according to the present invention. A chamber 2 of the device 1 comprises a base 5 formed by a substrate comprising 18 recesses 7. A top 6 is located opposite the base 5, and a distance 8 between the base 5 and the top 6 is less than a width 9 of at least one of the recesses 7. A hollow body 14 is located between the chamber 2 and the at least one recess 7, and a width of the hollow body 14 is equal to the width 9 of the at least one recess 7. The device 1 may also comprise a spacer disposed between the top 6 and the base 5 of the chamber 2, the spacer having a height corresponding to the distance 8 between the base 5 and the top 6 of the chamber 2.

[0037] According to another preferred embodiment of the present invention, the base body comprises the base of at least one chamber, the top body comprises the top of at least one chamber, and the base body and the top body are reversibly sealed to each other. As used herein, "reversibly sealed" means that the base body and the top body of the present invention can be attached and detached to each other at least once. After the base body and the top body are attached, the device can be leak-proof. The attachment of the base body and the top body can be achieved by mechanical, physical, and / or chemical methods. For example, the base body and the top body can be mechanically attached by a locking mechanism.

[0038] Preferably, the base body and the top body are attached to each other by adhesive or a locking mechanism. For example, the base body and the top body of the present invention can be detached from each other by simply opening the locking mechanism or by lifting the top body from the base body, thereby non-destructively releasing both bodies from the adhesive. After detaching the top body from the base body, the open side of at least one recess of the present invention is accessible, and a fluid containing cells can be applied to at least one chamber through at least one opening in the device.

[0039] According to another preferred embodiment of the present invention, the device is a microfluidic device, and the chamber comprises at least one opening for introducing a fluid into the chamber and at least one opening for removing a fluid from the chamber. Surprisingly, it has been found that the microfluidic device of the present invention exhibits excellent capabilities for transporting and / or storing cells, particularly as cell aggregates. Using the microfluidic device of the present invention, cells and cell aggregates can be transported and / or stored in a reliable, compact, and cost-effective manner. As described above, the size of the cell aggregates can be limited by the width of at least one recess, which limits the opportunity for backflow into the chamber. Furthermore, due to the limited volume of the microfluidic device of the present invention, even less fluid is required for storing and / or transporting the cell aggregates. For example, cell aggregates can be delivered at significantly lower costs compared to current delivery methods due to the limited fluid volume required and reduced packaging weight.

[0040] Thus, the microfluidic device of the present invention comprises at least one chamber having at least one opening for introducing fluid into the chamber and at least one opening for removing fluid from the chamber, wherein the at least one chamber has a base and a top, the top being located opposite the base, the base being formed by a substrate including at least one recess for collecting fluid, wherein the distance between the base and the top of the at least one chamber is less than the width of the at least one recess, and the width of the at least one recess is the smallest line segment between two opposing points passing through the center of the base region of the at least one recess.

[0041] Fluids can also be applied to the microfluidic device by introducing them into at least one chamber via at least one fluid reservoir. According to another preferred embodiment of the present invention, at least one opening is connected to at least one fluid reservoir. The at least one reservoir has the advantage of being able to be filled with sufficient fluid required for the storage and / or transport of cell aggregates. The fluid reservoirs of the microfluidic device of the present invention may have any shape and may, for example, have a defined volume for capturing sufficient fluid to provide a specific level of fluid to at least one chamber. The volume of the at least one reservoir can be adapted depending on the expected storage and / or transport time of the cell aggregates and the intended area of ​​use. One major advantage of the present invention is that the volume of fluid required for the transport and / or storage of cell aggregates is significantly reduced compared to, for example, the volume of a culture flask.

[0042] According to another preferred embodiment of the present invention, at least one reservoir has a diameter of 1 mm 3 ~5000mm 3 , preferably 2 mm 3 ~4000mm 3 , preferably 5 mm 3 ~2000mm 3 , preferably 10 mm 3 ~1000mm 3 , preferably 20 mm 3 ~500mm 3 It has a volume of

[0043] 2a-2c show schematic plan views of an embodiment of a microfluidic device 10 according to the present invention. The microfluidic device 10 comprises a chamber 2 having a fluid inlet 3 for introducing a fluid into the chamber 2 and a fluid outlet 4 for removing the fluid from the chamber 2. The chamber 2 further comprises a base 5 formed by a substrate having fifteen recesses 7. An apex 6 is located opposite the base 5, and a distance 8 between the base 5 and the apex 6 is less than a width 9 of at least one of the recesses 7. A hollow body 14 is located between the chamber 2 and the at least one recess 7, and the width of the hollow body 14 is equal to the width 9 of the at least one recess 7.

[0044] 3a and 3b show schematic plan views of another embodiment of a microfluidic device 15 according to the present invention. Microfluidic device 15 is distinguished from microfluidic device 10 according to FIGS. 2a-2c in the fact that chamber 2 of microfluidic device 10 is essentially embedded in a substrate that forms the base 5 of chamber 2. In contrast, microfluidic device 15 according to the present invention has a flat base 11 that includes 15 recesses 7, and chamber 2 is embedded in an upper layer of device 15. FIGS. 3a and 3b show a microfluidic device 15 according to the present invention having base 11 attached to an upper layer that forms the top 12 of chamber 2. A hollow body 14 is located between chamber 2 and at least one recess 7, and the width of hollow body 14 is equal to the width 9 of at least one recess 7. Microfluidic device 15 is further distinguished from microfluidic device 10 according to FIGS. 2a-2c in the fact that recesses 7 of microfluidic device 10 are arranged in a 1536-well plate footprint. Therefore, the microfluidic device 15 of the present invention is suitable for standardized laboratory processes such as plate reader measurements, automated liquid handling procedures, automated imaging, and the like.

[0045] Elements of the microfluidic device 15 that are similar to elements of the microfluidic device 10 according to figures 2a-2c are designated with the same reference numerals. The base 5; 11 may also be provided with a different number of recesses 7.

[0046] Figure 4a shows a schematic plan view of an embodiment comprising six microfluidic devices 10 according to Figures 2a to 2c, the individual chambers 2 of the microfluidic devices 10 being embedded in one base body.

[0047] Figure 4b shows a schematic plan view of an embodiment comprising six microfluidic devices 15 according to Figures 3a and 3b, in which 15 recesses 7 arranged in the footprint of a 1536-well plate are contained in one base body.

[0048] Figures 5a and 5b show a schematic plan view of the upper layer of the microfluidic device 10 according to Figures 2a-2c, which comprises six pairs of fluid reservoirs 13. The fluid reservoirs 13 are connected to one opening 3 for introducing fluid into the chambers 2 and one opening 4 for removing fluid from the chambers 2. The upper layer can also comprise various chamber structures that fit into the flat base 11, as shown, for example, in the embodiment of the microfluidic device 15 according to Figures 3a and 3b.

[0049] The substrate of the microfluidic device can comprise, consist of, or be coated with a biocompatible material, such as silicone, a plastic material, or glass. Silicone and glass are typically processed using standard photolithography techniques, providing rapid and easy fabrication of microfluidic devices. The microfluidic devices of the present invention can be produced by microfabrication methods known in the art, such as casting, 3D printing, lithography, hot embossing, or microinjection molding.

[0050] As described above, the base body includes a base of at least one chamber, and the top body includes a top of at least one chamber. According to another embodiment of the present invention, the top of the chamber is detachable from the base. At least one chamber of the device of the present invention can be closed by attaching the top and base together, and the distance between the base and top of the closed chamber is smaller than the width of at least one recess. Therefore, after attaching the base and top, the size of the cell aggregate can be limited by the width of at least one recess.

[0051] According to another preferred embodiment of the present invention, the device includes a spacer disposed between the top and base of the chamber, the spacer having a height corresponding to the distance between the base and the top of the chamber when the top of the chamber is attached to the base. As mentioned above, the distance between the base and top of the chamber is important, and the spacer of the present invention makes it possible to maintain this distance. The presence of the spacer is also user-friendly, since it automatically ensures the proper chamber height according to the present invention and avoids manual adjustment of this essential distance between the base and top.

[0052] According to another preferred embodiment of the present invention, the base is circular and the spacers are disposed around the periphery of the circular base.

[0053] According to another further preferred embodiment of the present invention, the spacers are arranged equidistantly along the periphery of the base.

[0054] The base and top can be attached to one another by a locking mechanism such as a threaded connection. According to another preferred embodiment, the top is connectable to the base via a threaded connection.

[0055] According to another preferred embodiment, the device comprises a base body comprising a base of a chamber and a top body comprising a top of the chamber, the base body comprising a cylindrical storage volume, the base being disposed at the bottom of the storage volume, the top body comprising an extension adapted to extend into the storage volume when the threaded connection is closed, the top being disposed at one end of the extension, and the threaded connection being disposed in the region of the opposite end of the extension. The distance between the base and top of at least one chamber may be less than the width of at least one closed recess. Cells in the device may form aggregates present in at least one recess of the device for transport and / or storage.

[0056] Another aspect of the present invention relates to a method for storing and / or transporting cell aggregates, wherein a fluid containing cells is applied to at least one chamber of the device defined above, and the cells are incubated until at least one aggregate is formed in at least one recess. According to the present invention, the cell aggregates can be stored and / or transported for a period of 1 to 10 days, preferably 2 to 8 days.

[0057] In particular, the present invention provides a method for the storage and / or transport of cells, preferably eukaryotic cells, preferably mammalian cells, preferably stem cells and / or tumor cells.

[0058] Surprisingly, it has been found that extracellular vesicles can also be stored and / or transported using the methods of the present invention. Extracellular vesicles can have diameters ranging from 20 to 5,000 nm and can be secreted by a wide variety of cell types. Generally, extracellular vesicles, such as exosomes, microvesicles, and apoptotic bodies, are membrane-bound and can be loaded with, for example, therapeutic substances. Exosomes are a type of extracellular vesicle that can be secreted by most eukaryotic cells. Microvesicles are another type of extracellular vesicle that bud outward from the cell surface membrane. Meanwhile, apoptotic bodies are extracellular vesicles formed from debris from dead cells. Exosomes, microvesicles, and apoptotic bodies can be released in vivo or in vitro, for example, in cell culture. Extracellular vesicles secreted by various cells are known to function as intercellular communication mediators in vivo and play an important role in the physiological phenomena of several diseases, including cancer.

[0059] Preferably, cells are stored and / or transported in the form of aggregates. It has been found that the method of the present invention allows cells to be transported and / or stored in the form of aggregates in a compact and cost-effective manner. Therefore, the required packaging size is reduced, making the delivery process simple and efficient at low cost. The method of the present invention requires far fewer reagents than other live cell delivery techniques. Preferably, cells are stored and transported under different conditions. For example, cell aggregates can be stored at temperatures ranging from -196 to 40°C. Cell aggregates can also be stored at lower temperatures, such as -80°C, and transported at room temperature or 37°C. Figure 6 shows a schematic workflow of a method of an embodiment of the present invention, including application of a cell suspension to a device of the present invention, incubation of the device to form cell aggregates, freezing the cell aggregates in the device of the present invention in liquid nitrogen (N2) for storage, thawing the aggregates after storage in a cell culture incubator, transportation of the device, disaggregation of the cell aggregates into individual cells, and seeding the resulting cell suspension into cell culture flasks. It has been found that the cells exhibit good viability after storage and / or transportation.

[0060] As used herein, the term "cell viability" refers to the number of viable eukaryotic and / or prokaryotic cells in a cell population.

[0061] Surprisingly, the method of the present invention demonstrates a reliable and cost-effective method for transporting and / or storing cell aggregates, preferably through the storage and / or transport of eukaryotic and / or prokaryotic cells, while ensuring good cell viability and a natural cellular environment through three-dimensional cell culture. Preferably, the cell-containing fluid also contains nutrients for supplying the cells, such as cell culture medium. If the cells are stored and / or transported under freezing conditions, the cell-containing fluid may contain a cryopreservation medium. Freezing and thawing of biological samples, such as cells, are important steps in the cryopreservation process, which can affect the recovery of viable cells after storage and / or transport. Cryopreservation media enable the cryopreservation of cells of various origins while maintaining high cell and tissue viability and recovery rates after thawing. Cryopreservation media are known in the art and may contain serum, dimethyl sulfoxide (DMSO), glycerol, or a combination thereof. Alternatively, the cryopreservation medium may be essentially serum-free and may contain DMSO, glycerol, or a combination thereof. Preferably, the cryopreservation medium is animal component-free, serum-free, and protein-free. It has been found that by mixing a cryopreservation medium with a CO2-independent medium, good cell viability can be achieved throughout the storage and / or transportation of frozen cells. CO2-independent media are also known in the art and can be used to support cell growth without a CO2 cell culture incubator. The cell-containing fluid can contain 5-95% by volume, preferably 10-90% by volume, preferably 10-60% by volume, preferably 10-40% by volume, preferably 10-40% by volume, preferably 15-30% by volume of at least one cryopreservation medium. Preferably, the fluid contains at least one cryopreservation medium and at least one CO2-independent medium in a ratio of 1:1 to 1:10, preferably 1:2 to 1:5 (cryopreservation medium:CO2-independent medium).

[0062] In order to use extracellular vesicles for analysis and diagnosis, they must first be concentrated and collected from biological samples such as blood, urine, saliva, etc. The methods of the present invention allow for easy and safe storage and / or transportation of concentrated extracellular vesicles.

[0063] Another advantage of the present invention relates to the possibility of storing and / or transporting cells of various types, sources, and / or patients. The method of the present invention has the advantage of allowing different samples to be stored and / or transported in a single device without the need for large packaging sizes. Different samples of cells, particularly in the form of cell aggregates, can be stored and / or transported in different chambers of a device, particularly a microfluidic device, allowing for direct sorting of each cell type, patient, etc., into each chamber. The method of the present invention requires far fewer reagents than other live cell delivery techniques. According to the method of the present invention, at least one device, preferably at least two devices, preferably at least three devices, preferably at least four devices, preferably at least five devices, preferably at least 10 devices, preferably at least 20 devices, preferably at least 30 devices, preferably at least 40 devices, preferably at least 50 devices, preferably at least 60 devices, preferably at least 70 devices, preferably at least 80 devices, preferably at least 90 devices, and preferably at least 100 devices can be simultaneously stored and / or transported.

[0064] According to another preferred embodiment of the present invention, the device is centrifuged after step a) at a speed of 50-500 rcf, preferably 150-300 rcf, to promote cell aggregation. It has been found that the cell aggregation time and aggregate shape can be efficiently optimized and enhanced by centrifugation of the device.

[0065] According to another preferred embodiment of the present invention, the applied fluid is 5 , preferably 2.5*10 5 , preferably 5.0*105 , 7.5*10 5 , 1.0*10 6 , preferably 2.0*10 6 , preferably 3.0*10 6 The cell density of a fluid can be determined by methods known in the art, such as using a hemocytometer.

[0066] To mimic the natural environment of the cell aggregates, preferably the cell aggregates within the device of the present invention, it is particularly preferred to apply a hydrogel to at least one chamber of the device, e.g., the hydrogel can form a matrix for the spheroids produced.

[0067] According to another preferred embodiment of the present invention, after step a) or b), a hydrogel is introduced into at least one chamber, the hydrogel consisting of at least one compound selected from the group consisting of polyethylene glycol, polyacrylamide, dextran, collagen, fibrin, fibronectin, laminin, hyaluronic acid, fibroin, alginate, cellulose, or combinations thereof.

[0068] Preferably, the cell aggregates can be harvested from the device according to the present invention after storage and / or transportation. After harvesting, the cell aggregates can be further used, for example, in biomedical research, pharmaceutical production, personalized medicine approaches, etc. To harvest the cell aggregates from the device, the hydrogel may have to be digested to access the individual cell aggregates. According to another preferred embodiment of the present invention, the hydrogel is digested with an enzyme selected from the group consisting of collagenase, hyaluronidase, cellulase, ethylenediaminetetraacetic acid (EDTA), sodium citrate, dispase, α-chymotrypsin, N-acetyl-cysteine, glutathione, dithiothreitol, and combinations thereof.

[0069] According to another preferred embodiment of the present invention, at least one aggregate and / or cell is collected from the device.

[0070] According to another preferred embodiment of the present invention, at least one cell aggregate and / or cell is collected by separating the top and bottom bodies as described above by collecting at least one cell aggregate and / or cell from at least one well. In particular, the top and bottom bodies of the device of the present invention are detached from each other, and the cell aggregate is collected, for example, by pipetting it from the device. Alternatively, after separating the top and bottom bodies, the hydrogel can be enzymatically digested. In this case, the top and bottom bodies can be carefully removed, and an enzyme can be added to the hydrogel containing the cell aggregate. After digestion of the hydrogel, the cell aggregate can be collected from the device.

[0071] Cell aggregates can also be disaggregated into individual cells.In particular, spheroids or organoids can be disaggregated into individual cells, or aggregates consisting of extracellular vesicles can be disaggregated into individual extracellular vesicles.This has the advantage that, for example, in the case of eukaryotic cells, individual cells can be further subcultured as monolayer cultures in cell culture flasks.According to another preferred embodiment of the present invention, cells are collected by disaggregating at least one aggregate into cells, and the cells are collected through at least one opening, and / or by separating the top body and the bottom body as defined above, and collecting the cells from at least one chamber.

[0072] According to another preferred embodiment of the present invention, disaggregation is achieved by applying a fluid comprising trypsin, collagenase, accutase, dispase, elastase, ethylenediaminetetraacetic acid (EDTA), sodium citrate, or a combination thereof to at least one aggregate.

[0073] A further aspect of the present invention relates to the use of the device defined above for the storage and / or transport of cells and / or cell aggregates. In particular, the device of the present invention can be used for the delivery of live cells in a compact, reliable, and cost-effective manner. Furthermore, the device can be used in personalized medicine approaches. For example, eukaryotic cells, preferably tumor cells or extracellular vesicles, from a patient's blood or urine can be collected using the device of the present invention and delivered to the required destination for screening, evaluation, and selection of an appropriate treatment. One major advantage of the present invention relates to the reduced amount of patient sample required compared to standard delivery options.

[0074] Another aspect of the present invention relates to a method for screening compounds on cell aggregates. In particular, the method of the present invention can be used to screen chemical libraries of synthetic molecules, natural products or extracts, traditional small molecule drugs usually derived from chemical synthesis, and biopharmaceuticals, including recombinant proteins, vaccines, therapeutically used blood products (e.g., intravenous immunoglobulin), gene therapy, monoclonal antibodies, and cell therapy (e.g., stem cell therapy). By applying various concentrations of compounds to the cell aggregates, it is possible to determine whether the substance has a beneficial or negative effect on the cells within the cell spheroids. Such methods can be used, for example, to identify doses of compounds that may have beneficial, toxic, inhibitory, and / or stimulatory effects on the cell aggregates.

[0075] FIG. 7 shows a schematic workflow of a method of an embodiment of the present invention, including applying a cell suspension to a device of the present invention, particularly a microfluidic device, incubating the device to form cell aggregates, treating the cell aggregates with at least one compound, e.g., by applying the compound via a pipetting robot, and measuring the effect of the compound on the aggregates via high-content and / or high-throughput screening. Cell aggregates can be processed in the device of the present invention, or the aggregates can be harvested from the device prior to compound treatment. In the latter case, the aggregates can be processed and analyzed on a separate cell culture platform, as known in the art. Preferably, at least one compound is applied to at least one cell aggregate present in a microfluidic device of the present invention, and the effect of the compound is measured on the aggregate. Alternatively, the cell aggregates can be processed and analyzed on the microfluidic device. Preferably, using the method of the present invention, cell aggregates can be generated and analyzed in a reliable and reproducible manner on a single microfluidic device. Furthermore, the microfluidic device may be compatible with standardized laboratory equipment. For example, fluids, cells, compounds, etc. can be applied to the microfluidic device by microchannel pipettes and pipetting robots, and the effect of compounds on cell aggregates can be determined by state-of-the-art plate readers. Thus, the physiological state of a patient can be profiled in a multiparametric and multimodal manner by the present invention.

[0076] Preferably, the cells are obtained from a mammalian source, preferably a human. The methods of the present invention can be used to determine physiological parameters and / or disease states "from bench to bedside", meaning that results obtained using the methods of the present invention can be used directly to develop treatment regimens for patients.

[0077] According to another preferred embodiment of the present invention, the cells are tumor cells, preferably selected from the group consisting of benign adenoma tumor cells, angiofibroma tumor cells, hemangioma tumor cells, leiomyoma tumor cells (fibroids), benign chorioangioma tumor cells, benign colon tumor cells, cystadenoma tumor cells, dermoid tumor cells, dendroid tumor cells, ductal carcinoma in situ (DCIS) tumor cells, fibroadenoma tumor cells, fibroma tumor cells, benign ganglioneuroma tumor cells, lipoma tumor cells, meningioma tumor cells, myxoma tumor cells, neurofibroma tumor cells, nevus tumor cells, osteochondroma tumor cells, pheochromocytoma tumor cells, polyposis tumor cells, Schwannoma tumor cells, prostatic intraepithelial neoplasia tumor cells, benign prostatic hyperplasia (hypertrophy) tumor cells, benign teratoma tumor cells, benign thymoma tumor cells, and Brenner tumor cells.

[0078] According to another preferred embodiment of the present invention, tumor cells are obtained by dissociating a solid tumor. As used herein, "solid tumor" refers to an abnormal mass of tissue that typically does not contain cysts or liquid areas. Solid tumors can be benign (not cancerous) or malignant (cancer). Different types of solid tumors are named after the type of cells that form them. Examples of solid tumors are sarcomas, carcinomas, and lymphomas. [Example]

[0079] Materials and Methods Microfluidic device fabrication: The microfluidic device according to the present invention was fabricated by double casting of polydimethylsiloxane (PDMS). A master mold containing the recess and chamber structures was fabricated in polymethylmethacrylate (PMMA) by CNC micromilling (Denz-Biomedical, Austria).

[0080] PDMS (Sylgard 184 silicone elastomer, Farnell, Austria) was mixed with a curing agent in a 10:1 weight ratio. The polymer was degassed in a vacuum chamber for 1 hour, poured onto a PMMA structure, and baked at 80 °C for 2 hours. The structure was then peeled from the PMMA matrix and hard-baked at 90 °C for 48 hours. This resulted in the final PDMS mold for fabricating the bottom layer. To ensure proper release of the PDMS structure from the mold, the surface of the PDMS mold was plasma-activated and silanized with trichloro(1H,1H,2H,2H-perfluorooctyl)silane (Sigma-Aldrich, Austria) under vacuum for 10 minutes, followed by baking at 80 °C for 1 hour. The mold for the top layer, containing the reservoirs, was 3D-printed by iMaterialise (Denmark). The PDMS master mix was poured into the 3D-printed mold and baked at 70 °C for 2 hours. Prior to bonding, each chamber was coated with 0.5 wt% antifouling Lipidure-CM5206 solution (AMSbio, UK) at 80 °C for 1 h. A 1.5 mm diameter hole was drilled in the reservoir layer using a biopsy puncher to connect the reservoir and chamber. The two PDMS layers (bottom and top layers with reservoirs) were bonded together by O2-plasma activation (Diener, Germany) at 0.9 mbar and 200 W for 30 s and baked at 80 °C overnight.

[0081] Cell culture: HeLa and Hek cells were grown in T75 flasks (Greiner, Austria) containing 10 mL of DMEM cell culture medium (Sigma-Aldrich, Austria) supplemented with 10% FBS (Sigma-Aldrich, Austria), 2 mM L-glutamine (Sigma-Aldrich, Austria), and 1% penicillin / streptomycin and cultured at 37 °C with 5% CO2. Cells were grown to 80-90% confluency for seeding into microfluidic devices. Prior to seeding, cells were detached from the growth flask by washing once with PBS (Sigma-Aldrich, Austria) and treated with 2 mL of trypsin-EDTA solution (Sigma-Aldrich, Austria) for 5 min. Detached cells were collected, counted, and adjusted to the appropriate concentration in complete growth medium.

[0082] Cell Loading: Before cell seeding, the chambers were filled with 70% ethanol and placed in an ultrasonic bath to remove air bubbles. The devices were sterilized by cleaning the chambers from ethanol by washing three times with 200 μL of 70% ethanol and three times with 200 μL of 1x PBS (Sigma-Aldrich, Austria) supplemented with 1% penicillin / streptomycin (Sigma-Aldrich, Austria). To avoid liquid evaporation, the devices were maintained and incubated in quadriPERM chambers (Sarstedt, Austria) filled with 2 mL of 1x PBS supplemented with 1% antibiotic / antimycotic solution (Sigma-Aldrich, Austria). Before cell seeding, PBS was removed from all reservoirs and preconditioned with 200 μL of cell culture medium. After removing the medium, 100 μL of cell suspension was added to each chamber. The next day, the chambers were flushed with 200 μL of growth medium to remove excess cells.

[0083] Assessment of cell viability: Cell viability was determined by live / dead staining. Therefore, 10 μg / mL Hoechst 33342 (Sigma-Aldrich, Austria), 2 μM calcein-AM (Invitrogen, Austria), and 4 μM EtBr (Invitrogen, Austria) were mixed in complete growth medium and applied to cell aggregates in the microfluidic device. The microfluidic device was placed in an Olympus IX83 fluorescence microscope at 37 °C and 5% CO2, and images were taken after a 30-hour incubation period. The fluorescence intensity of the different channels of the cell aggregates (blue / Hoechst 33342 / total cells; green / calcein-AM / live cells; red / EtBr / dead cells) was measured using ImageJ.

[0084] CFD Simulation: All designs for CFD simulation were performed using AutoCAD software (Autodesk). The SAT files from the generated designs were loaded into Autodesk CFD software (Autodesk). Water properties (Autodesk presets) were assigned to the models, while the simulated flow rate was set to 10 μL / min and atmospheric pressure was set for the outlet portion of the microfluidic device. All models were simulated with these settings.

[0085] result Computational fluid dynamics (CFD) simulations were performed to estimate the flow profiles of microfluidic flow in a device according to the present invention under different operating conditions. Velocity magnitudes were determined computationally to evaluate the effect of three different channel heights at a fixed simulated flow rate of 10 μL / min. The results in Figures 8a and 8b show a more homogeneous distribution of fluid flow at a low chamber height of 50 μm compared to a high height of 150 μm. These findings surprisingly demonstrate that a low chamber height results in fluid streamlines that uniformly surround the entire array of recesses in the microfluidic device without turbulence, compared to a high chamber height, thus indicating more efficient medium turnover inside the recesses at low chamber heights.

[0086] Furthermore, it has been observed that loss and / or damage to spheroids can be avoided in microfluidic devices with chamber heights that are smaller than the width of the recesses compared to devices with chamber heights that are larger than the width of the recesses.

[0087] To evaluate the effect of the hollow body width on the microfluidic flow profile within the device, we performed (CFD) simulations at a constant simulated flow rate of 10 μL / min. The results in Figures 9a and 9b show that fluid flow within the recesses can be enhanced by increasing the width of the hollow body. This effect results in better fluid supply of cells, e.g., with nutrients, and improved cell capture within the recesses during application of the cell suspension.

[0088] To evaluate the optimal storage and / or storage conditions for cells in the microfluidic device according to the present invention, HeLa cells were applied to two different devices. One device was stored under cell culture conditions (37°C, 5% CO2 atmosphere), and the second device was stored at room temperature. After overnight storage of both devices, the viability of cells in the form of spheroids was evaluated. The results in Figure 10 show that cultured HeLa cell aggregates did not lose significant viability after 24 hours of culture in the microfluidic device, compared to culture conditions at 37°C, 5% CO2, and room temperature.

[0089] Furthermore, cell aggregates cultured at room temperature for 48 hours could be harvested from the microfluidic device by digesting the aggregates and removing the cell-containing liquid. Furthermore, as shown in Figure 11, the harvested cell suspensions seeded on cell culture plates showed the same cell concentration trends as those seeded on the microfluidic device. These results demonstrate that viable HeLa cells could be obtained over a wide range of seeding densities in culture flasks after storage in the form of cell aggregates in the microfluidic device of the present invention.

[0090] Furthermore, the influence of the storage medium was examined in more detail. Cell aggregates of HeLA and Hek cell lines were incubated for 3 days in different concentrations of cryopreservation medium (NutriFreez® (Sartorius)) in CO₂-independent medium (Gibco™ CO₂-independent medium, Fisher Scientific). After incubation, the cell aggregates were harvested by digestion, and the cell viability of the cells was determined in 96-cell culture plates. Figure 12 shows that after 3 days of incubation, the cells showed good results in terms of cell viability at a cryopreservation medium concentration of less than 30% by volume for the HeLa and Hek cell lines. Furthermore, the cells, especially HeLa cells, showed good viability at a cryopreservation medium concentration of 15% by volume.

[0091] Conclusion: The design of the microfluidic device was optimized for a streamlined (e.g., no voids or dead volumes) flow profile through adaptation of the channel height and recess shape. Results from CFD simulations determined that reducing the channel height significantly affected the flow profile within the microfluidic device. This optimized flow profile resulted in better nutrient supply for the trapped cell aggregates while simultaneously improving cell capture within the recesses. The microfluidic device can form cell aggregates from a solution containing individual cells and retain a similar number of cells in each recess. In summary, the device according to the present invention is an easy and cost-effective tool for the storage and / or transport of cell aggregates for a wide range of applications.

Claims

1. A device (1; 10; 15) for storing and / or transporting cells, in particular cell aggregates, comprising at least one chamber (2) having a base (5; 11) and a top (6; 12), the top (6; 12) being located opposite the base (5; 11), the base (5; 11) being formed by a substrate comprising at least one recess (7) for collecting a fluid, wherein the distance (8) between the base (5; 11) and the top (6; 12) of the at least one chamber (2) is less than the width (9) of the at least one recess (7), the width (9) of the at least one recess (7) being the smallest line segment between two opposite points passing through the center of the base region of the at least one recess (7).

2. 2. The device (1; 10; 15) of claim 1, wherein the base (5; 11) of the at least one chamber (2) further comprises a hollow body (14), the hollow body (14) being fluidly connected to the at least one recess (7) and the interior of the at least one chamber (2), and the width of the base region of the hollow body (14) is at least partially the width (9) of the at least one recess (7).

3. The device (1; 10; 15) according to claim 2, wherein the width of the top region of the hollow body (14) is between 500 μm and 3 mm, preferably between 1 mm and 2 mm, and said width of the hollow body (14) is the smallest line segment between two opposite points passing through the center of the top region of the at least one recess (7).

4. 4. A device (1; 10; 15) according to claim 2 or 3, wherein the hollow body (14) has the shape of a truncated cone, the base and top regions of the truncated cone having the shape of a circle or an ellipse.

5. A device (1; 10; 15) according to any one of claims 1 to 4, wherein the ratio of the distance (8) between the base (5; 11) and the top (6; 12) of the at least one chamber (2) to the width (9) of the at least one recess (7) is between 0.5:1 and 0.01:1, preferably between 0.2:1 and 0.02:1, preferably between 0.1:1 and 0.04:

1.

6. The device (1; 10; 15) according to any one of claims 1 to 5, wherein said at least one recess (7) has the shape of an ellipsoidal paraboloid or a hemisphere.

7. A device (1; 10; 15) according to any one of the preceding claims, wherein said at least one recess (7) has a width (9) of between 100 μm and 3 mm, preferably between 200 μm and 2 mm, more preferably between 500 μm and 1.5 mm.

8. A device (1; 10; 15) according to any one of claims 1 to 7, wherein a base body comprises the base (5; 11) and a top body comprises the top (6; 12) of the at least one chamber (2), the base body and the top body being reversibly sealed to each other.

9. The device (10; 15) according to any one of claims 1 to 8, wherein the device is a microfluidic device and the chamber (2) comprises at least one opening (3) for introducing a fluid into the chamber (2) and at least one opening (4) for removing a fluid from the chamber (2).

10. 10. The device (10; 15) according to claim 9, wherein said at least one opening (3, 4) is connected to at least one fluid reservoir (13).

11. A device (10; 15) according to any one of claims 1 to 8, wherein the top (6; 12) of the chamber (2) is detachable from the base (5; 11).

12. 12. The device (1) of claim 11, comprising a spacer arranged between the top (6) of the chamber (2) and the base (5), the spacer having a height corresponding to the distance (8) between the base (5) and the top (6) of the chamber (2) when the top (6) of the chamber (2) is attached to the base (5).

13. 13. The device (1) according to claim 12, wherein the base (5) is circular and the spacers are arranged around the periphery of the circular base (5).

14. 14. The device (1) according to claim 13, wherein the spacers are equidistantly spaced along the periphery of the base (5).

15. The device (1) according to any one of claims 11 to 14, wherein the top part (6) is connectable to the base part (5) via a threaded connection.

16. 16. The device (1) according to claim 15, comprising a base body comprising the base (5) and a top body comprising the top (6; 12) of the chamber (2), the base body comprising a cylindrical storage volume, the base (5) being arranged at the bottom of the storage volume, the top body comprising an extension adapted to extend into the storage volume when the screw connection is closed, the top (6) being arranged at one end of the extension and the screw connection being arranged in the region of the opposite end of the extension.

17. 1. A method for the storage and / or transport of cells, in particular cell aggregates, comprising: a) applying a fluid containing cells into said at least one chamber (2) of the device (1; 10; 15) according to any one of claims 1 to 16, thereby providing said fluid in said at least one recess (7); b) incubating said cells until at least one aggregate is formed in said at least one recess (7).

18. 18. The method of claim 17, wherein a hydrogel is introduced into at least the chamber (2) after step a) or b), the hydrogel consisting of at least one compound selected from the group consisting of polyethylene glycol, polyacrylamide, dextran, collagen, fibrin, fibronectin, laminin, hyaluronic acid, fibroin, alginate, cellulose, or a combination thereof.

19. 19. The method of claim 18, wherein the hydrogel is digested by an enzyme selected from the group consisting of collagenase, hyaluronidase, cellulase, ethylenediaminetetraacetic acid (EDTA), sodium citrate, dispase, α-chymotrypsin, N-acetyl-cysteine, glutathione, dithiothreitol, and combinations thereof.

20. 20. The method according to any one of claims 17 to 19, wherein the at least one cell aggregate and / or the cells are collected from the device (1; 10; 15) after step b).

21. Use of a device (1; 10; 15) according to any one of claims 1 to 16 for the storage and / or transport of cells, in particular cell aggregates.

22. 1. A method for screening the effect of a compound on cell aggregates, comprising: a) providing a solution comprising cells; b) applying the solution of step a) to the at least one chamber (2) of the device (1; 10; 15) according to any one of claims 1 to 16, thereby providing the fluid in the at least one recess (7); c) incubating the cells until the at least one cell aggregate is formed in the at least one recess (7); d) treating said at least one cell aggregate with said at least one compound; d) measuring the effect of said at least one compound on said at least one cellular aggregate.

Images