The present disclosure relates in general to a cell culture device that provides an area which contains cells and an area which is free of cells. In one application, the cell culture device can be used to perform assays to determine activity of a chemical entity, or cell motility assays.
Cell migration and related processes are critical components of many physiologically important processes such as wound healing, angiogenesis, embryogenesis, cancer metastasis, and immune response. A variety of methods have been developed for studying the migratory behavior of cells. These methods fall into two categories: those involving devices that can generate chemical gradients, such as Transwell® (Corning, Incorporated, Corning, N.Y.) and Boyden chambers, and those involving devices that can create cell-free areas in cell monolayers.
The Transwell® and Boyden chambers, which involve the migration of cells through a microporous filter in response to a chemotactic gradient, are among the most commonly-used devices for studying cell migration and invasion. However, these devices are limited to the studies of cells that migrate individually or migrate in response to a chemical gradient, typically do not permit real-time viewing of the cells, and require the migrated cells be stained or lysed for analysis.
The creation of cell-free areas in cell monolayers is an important component of scratch/wound migration assays. The scratch/wound assays enable measurements of cell migration in the absence of a chemo-attractant. They often involve creating cell-free areas using tools such as a pipette tip, a syringe needle, a razor blade, electric current, and laser light. While enabling the monitoring of cellular responses in real-time, creating the cell-free area using these devices often results in damage to the cells, e.g., at the edge of the wound, and to the cell culture surface. In addition, the resulting cell-free areas are often inconsistent in one or more of size, shape and location.
More recently, several cell-exclusion patterning methods have been developed as improved alternatives to the scratch/wound methods. These tools include silicone stoppers, and biocompatible gel (BCG) to block the attachment of cells in predetermined areas during cell seeding. As with the scratch/wound methods, these patterning methods also involve the creation of cell-free areas in confluent cell monolayers. However, they do so using tools that minimize cell damage and create cell-free areas of uniform size and shape.
Both the silicone stoppers and BCG have been developed to provide a more reproducible alternative to the scratch/wound closure assay, and a less cumbersome method than Transwell®/Boyden chamber devices for cell migration studies. For assays where the cell culture surface is coated with an extracellular matrix (ECM), however, the direct contact of the silicone stoppers and BCG with the ECM, as required by these approaches, may result in alteration of the ECM structure. In addition, it may leave behind undesirable residues.
The following references describe the state of-the-art, the contents of which are hereby incorporated by reference in their entirety. WIPO International Publication No. WO2009/026359, US Patent Application Publication No. 2009/0054162, Rehydration of Polymeric, Aqueous, Biphasic System Facilitates High Throughput Cell Exclusion Patterning for Cell Migration Studies, Tavana et al., Adv. Funct. Mater. 2011, 21, 2920-2926, and A high-throughput cell migration assay using scratch wound healing, a comparison of image-based readout methods, Yarrow et al., BMC Biotechnology 2004, 4:21.
In view of the foregoing, it would be advantageous to provide improved approaches to cell-exclusion patterning.
The present disclosure relates to devices and methods for cell-exclusion patterning, and particularly devices and methods to exclude cells in selected areas during cell seeding so as to create cell-free arrays that can be used for cell migration and related studies and assays.
The disclosure provides a kit for cell-exclusion patterning that includes a multi-well culture plate comprising a plurality of wells. The multi-well plate includes a frame comprising at least a first side panel and a second side panel, wherein the first side panel optionally comprises a plurality of guide holes. The second side panel may also comprise a plurality of guide holes.
In embodiments, the kit further comprises a comb or a pin plate each comprising a plurality of blocking pins. The comb comprises a comb having a bar, at least one guide pin extending from the comb bar, and a plurality of blocking pins extending from the comb bar, each pin having a bottom surface. A comb comprises at most a single row of blocking pins. The at least one guide pin is structured and arranged to engage with a first side panel of the multi-well plate and the plurality of blocking pins are structured and arranged to extend into a plurality of respective wells. In an example embodiment, the comb comprises two guide pins, a first guide pin structured and arranged to engage with a first side panel of the multi-well plate, and a second guide pin structured and arranged to engage with a second side panel of the multi-well plate.
The plate comprises a plurality of blocking pins extending therefrom. A pin plate comprises plural rows of blocking pins. The pin plate is structured and arranged to engage with a first side panel of the multi-well plate such that the plural rows of blocking pins extend into a plurality of respective wells of the multi-well plate.
Thus, in one embodiment, disclosed is a kit for making a multi-well cell plate for cell-exclusion patterning. The kit includes (i) a comb comprising a comb bar, at least one guide pin extending from the comb bar, a plurality of blocking pins extending from the comb bar, each having a bottom surface; and (ii) a multi-well plate, wherein the multi-well plate comprises a plurality of wells, each well having side walls and a well bottom, a first side panel and a second side panel, wherein the first side panel comprises a plurality of guide holes.
The at least one guide pin is structured and arranged to engage with one of the plurality of guide holes of the first side panel of the multi-well plate such that when the at least one guide pin is engaged with one of the plurality of guide holes, the plurality of blocking pins are inserted into the plurality of wells.
In a further embodiment, the kit includes (i) a pin plate having plural rows of blocking pins extending from the pin plate, each blocking pin having a bottom surface; and (ii) a multi-well plate, wherein the multi-well plate comprises a plurality of wells, each well having side walls and a well bottom, a first side panel and a second side panel.
The pin plate is structured and arranged to engage with the multi-well plate in order to insert the blocking pins into respective ones of the plurality of wells of the multi-well plate. The pin plate may further comprise a plurality of access ports for seeding and feeding of cells into the wells.
The multi-well plate may comprise, for example, a 96-well plate or a 384-well plate. The blocking pins may be cylindrical (e.g., columnar) having any desired cross-section. The blocking pins may have a flat bottom surface. In embodiments, while engaged with the multi-well plate, the bottom surface of each blocking pins does not contact the respective well bottom, and thus provides a non-contact device for cell-exclusion patterning. In embodiments, the flat bottom surface of the blocking pins is parallel to the well bottom.
A method of using the kit for cell-exclusion patterning comprises (a) engaging the comb with the multi-well plate so that the at least one guide pin is engaged with one of the plurality of guide holes of the first side panel of the multi-well plate and the plurality of blocking pins are inserted into the plurality of wells, or engaging the pin plate with the multi-well plate so as to insert a plurality of blocking pins into a plurality of wells; (b) adding cell culture media to the wells of the multi-well plate; (c) adding cells to the wells of the multi-well plate; (d) allowing cells to settle and adhere to the bottom of the wells of the multi-well plate and (e) removing the comb or pin plate from the multi-well plate.
The comb enables patterning of a discrete number of wells within the multi-well plate, while the pin plate enables a higher throughput patterning of, for example, all or substantially all of the wells in the multi-well in a single step. A 96-pin plate or a 384-pin plate, for example, enables all of the pins to be handled as a single unit, and can be used to create cell-free areas without contacting the pins with the cell culture surface and/or without the need for subsequent cell washing.
Additional aspects of the disclosure will be set forth, in part, in the detailed description, figures and any claims which follow, and in part will be derived from the detailed description, or can be learned by practice of the various embodiments. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the embodiments as disclosed.
A more complete understanding of the disclosure may be had by reference to the following detailed description when taken in conjunction with the accompanying drawings wherein:
This disclosure provides high-throughput cell-exclusion patterning devices and related methods to partition cells into cell-containing and cell-free areas during cell seeding so that subsequent migration and growth of cells from cell areas to cell-free areas can be observed, recorded and analyzed. In particular, this disclosure provides a device and method for patterning and depositing living cells in predetermined areas by a mechanism that does not involve direct contact of the device with the cell culture surface. The device and method therefore enable cell patterning without damage or change to either the cells or the cell culture surface. The device is simple and easy to use and comprises a set of equally spaced pins that 1) can be lowered into wells of microtiter plates so that the bottom surface of each pin is near but not touching the bottom of the wells, and 2) can function as a non-contact mask for blocking the deposition of cells in selected areas during cell seeding.
The blocking pins 202 serve to block the deposition of cells during cell seeding, and hence create cell-free areas whose shape and size depend on the shape and size of the pins. In embodiments, the blocking pins can be of any cross-sectional shape, for example, round, oval, triangular, square, rectangular, and the like.
The guide pins 201 center the blocking pins in each corresponding well, fix the height of the blocking pins, prevent them from touching the bottom of the wells, and prevent the insert and hence the blocking pins from becoming dislodged during cell seeding and other handling steps.
Referring to
A kit embodiment including an alignment frame is illustrated in
The pin plate is a rigid structure that can be lowered into or removed from the well plate. By holding the skirt of the well plate and the sidewalls of the pin plate during these processes, the two plates can be joined or separated from each other. The pin plate 500 has sidewalls with dimensions that serve several important functions: 1) they allow the pin plate to sit form-fittingly on the skirt of the well plate and prevent the blocking pins from becoming dislodged during cell seeding and other handling, 2) they allow the blocking pins and adjacent access ports to align with the corresponding wells, and 3) they allow the tip of each blocking pin to be positioned proximate, but not in contact with the well bottom. The pin plate's sidewalls thus act as the guiding tabs for the blocking pins and access ports. A method of using the multi-well plate 100 and pin plate 500 is essentially as described above with reference to
Compared to existing technologies for cell-exclusion patterning, which rely on the direct contact of seeding stoppers and biocompatible gel (BCG) deposits with a well-bottom, the blocking pin insertion devices described here offer a non-contact method that can exclude cells in selected areas during cell seeding. The comb and pin plate thus have all of the advantages of the seeding stoppers and BCG deposits. For example, like seeding stoppers and BCG deposits, the comb and plate yield cell-free areas with consistent shape, size and location, avoid cell damage, are simple and easy to use, compatible with adherent cells, and are suitable for subsequent high-throughput screening (HTS) and high-content analysis (HCA).
In contrast to seeding stoppers and BCG deposits, the comb and plate (because they are non-contact) do not interfere with the cell culture surface, and are suitable for patterning non-adherent cells. Further, both the comb and plate allow subsequent cell migration studies to be carried out with or without the blocking pins still present in the wells. For instance, if the wells are coated with a material to enhance cell culture, the insertion of a blocking pin that comes into contact with the cell bottom might disrupt the coating. In addition, the addition of a BCG may result in an undesired BCG residue.
Using the comb or pin plate and multi-well devices embodied herein, it is possible to form a cell exclusion cell culture, while preserving a cell culture surface on the bottom of a well. As shown in
In embodiments, the multi-well plate, lid and the comb or pin plate (including blocking pins) can be formed from any suitable material including plastic, glass, glass-ceramic, metal, metal alloy, or combinations thereof. Suitable plastic materials include polystyrene, polycarbonate, acrylic, polystyrene, or polyester, or any other polymer suitable for molding and commonly utilized in the manufacture of laboratory ware.
The blocking pins may be solid or hollow. The comb and pin plate may be disposable or autoclavable. A disposable comb or pin plate may be formed from material that is less durable than a reusable, autoclavable material. For example, a reusable, autoclavable comb or pin plate may be formed from metal, while a disposable comb or pin plate may be formed from plastic material. In embodiments, one or more of the multi-well plate, lid, comb or pin plate are optically transparent.
The comb (or pin plate) and blocking pins may comprise a unitary part, such as an injection molded part, where the comb (or pin plate) and the blocking pins are formed from the same material as a single unit. Alternatively, blocking pins may be formed separately and attached to a comb or pin plate. In such a case, where the blocking pins are formed separately and attached to a comb or pin plate, the blocking pins may formed from the same material as the comb or pin plate or from different materials. For example, a comb or pin plate may be formed from an injection molded plastic and the blocking pins may be formed from a ceramic, glass-ceramic, polymer, metal or metal alloy such as tungsten carbide or stainless steel.
The comb, with guide pins that can fit snuggly into guide holes in the frame of a multi-well plate serves several functions including: (1) centering the blocking pins in each corresponding well; (2) fixing the height of the blocking pins and preventing them from touching the bottom of the wells; and (3) preventing the blocking pins from becoming dislodged during cell seeding and other handling steps.
Embodiments described herein will be further clarified by the following examples.
Materials. Cytochalasin D was obtained from Tocris Bioscience and dissolved in dimethylsulfoxide to give 50 mM stock solutions.
Human lung carcinoma cell line A549 and human cervical carcinoma cell line HeLa were obtained from American Type Culture Collection (ATCC). Both cell lines were cultured in Dulbecco's Modified Eagle Medium (DMEM) supplemented with 10% fetal bovine serum and 1% penicillin-streptomycin (complete medium).
Cell-exclusion patterning was carried out by a sequence of steps, as illustrated in
Cell patterns were imaged by bright-field or fluorescent microscopy or by using Corning Epic® label-free high-resolution optical resonance detection system (available from Corning Incorporated, Corning, N.Y.). The Epic® detection platform includes an optical detection unit and a 384-well microplate with resonant waveguide grating biosensors embedded in the bottom of each well. The optical detection unit measures changes in the local index of refraction due to the presence of cells and changes in cell response at the sensor surface.
Cytochalasin D (CytoD) was added to wells to assess the effect of this drug on cell proliferation and migration.
A549 cells were seeded at 8000 cells/well. Resonant wavelength distribution heat maps reflecting the growth and migration of A549 on an Epic® biosensor were captured using Corning EPIC® label-free high-resolution optical resonance detection systems with optical resolutions of 12 microns (
Disclosed is a high-throughput device and method to partition cells into cell-containing and cell-free areas during cell seeding so that subsequent cell migration can be observed, recorded, and analyzed. In particular, the disclosure provides a simple and easy-to-use pin comb or pin plate for patterning cells in multi-well plates without damage or change to either the cells or the cell culture surface. The pin plate, for example, is a lid-like device that conforms to multi-well plates and that comprises a like number of pins for blocking the deposition of cells into the well centers. A pin plate may further comprise plural access ports for seeding and feeding of cells into the wells. The device is suitable for real-time and endpoint measurements, and is compatible with plate readers and image-based detection systems. The device may be used with co-cultures.
As used herein, the singular forms “a,” “an” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to a “blocking pin” includes examples having two or more such “blocking pins” unless the context clearly indicates otherwise.
Ranges can be expressed herein as from “about” one particular value, and/or to “about” another particular value. When such a range is expressed, examples include from the one particular value and/or to the other particular value. Similarly, when values are expressed as approximations, by use of the antecedent “about,” it will be understood that the particular value forms another aspect. It will be further understood that the endpoints of each of the ranges are significant both in relation to the other endpoint, and independently of the other endpoint.
Unless otherwise expressly stated, it is in no way intended that any method set forth herein be construed as requiring that its steps be performed in a specific order. Accordingly, where a method claim does not actually recite an order to be followed by its steps or it is not otherwise specifically stated in the claims or descriptions that the steps are to be limited to a specific order, it is no way intended that any particular order be inferred. Any recited single or multiple feature or aspect in any one claim can be combined or permuted with any other recited feature or aspect in any other claim or claims.
It is also noted that recitations herein refer to a component being “configured” or “adapted to” function in a particular way. In this respect, such a component is “configured” or “adapted to” embody a particular property, or function in a particular manner, where such recitations are structural recitations as opposed to recitations of intended use. More specifically, the references herein to the manner in which a component is “configured” or “adapted to” denotes an existing physical condition of the component and, as such, is to be taken as a definite recitation of the structural characteristics of the component.
While various features, elements or steps of particular embodiments may be disclosed using the transitional phrase “comprising,” it is to be understood that alternative embodiments, including those that may be described using the transitional phrases “consisting” or “consisting essentially of,” are implied. Thus, for example, implied alternative embodiments to a well comprising culture media and cells include embodiments where a well consists of culture media and cells and embodiments where a well consists essentially of culture media and cells.
It will be apparent to those skilled in the art that various modifications and variations can be made to the present invention without departing from the spirit and scope of the invention. Since modifications, combinations, sub-combinations and variations of the disclosed embodiments incorporating the spirit and substance of the invention may occur to persons skilled in the art, the invention should be construed to include everything within the scope of the appended claims and their equivalents.
This application is a continuation-in-part of U.S. application Ser. No. 13/450,852, filed Apr. 19, 2012, the contents of which is relied upon and incorporated herein by reference in its entirety, and the benefit of priority under 35 U.S.C. §120 is hereby claimed.
Number | Date | Country | |
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Parent | 13450852 | Apr 2012 | US |
Child | 14273940 | US |