Patent Description:
The use of microcarriers in the biopharmaceutical industry is well known. Microcarriers can support the growth of anchorage-dependent cells thereon. Because of this, microcarriers are regularly used during cell culturing to optimize growth of various anchorage-dependent cell lines, such as protein-producing or virus-generating adherent cell populations, which are commonly used in the production of biologics (proteins) and vaccines.

Microcarriers have a surface chemistry that allows for attachment and growth of the anchorage dependent cells in cell culture procedures. Microcarriers can be made from a number of different materials and typically have a density that allows them to be maintained in suspension with gentle stirring.

Microcarrier cell culturing is typically carried out in a bioreactor. During culturing, the cells grow on the surface of the microcarriers. Once the cell culturing process is completed, the cultured cells are detached from the microcarriers through a chemical process carried out in the solution. The cultured solution containing the cells is then separated from the microcarriers for use or further processing. The gathered microcarriers can be cleaned, sterilized, and re-used, or can be discarded.

Separation of the microcarriers from the cultured solution that includes the detached cells is typically achieved by passing the solution through a rigid container having a horizontal screen that extends across the rigid container. The screen is a rigid mesh that allows the cultured fluid to pass through but prevents the microcarriers from doing so. However, as the microcarriers build up on the screen, they begin to clog the screen and prevent the fluid from passing therethrough. Once the screen is clogged, the process stops until the screen is unclogged. Furthermore, once the process is completed, the rigid container and related screen must be cleaned and sterilized before it can be reused. These process steps can be expensive and time consuming.

Accordingly, what is needed in the art are methods and/or systems that can alleviate one or more of the above problems.

The following prior art documents are acknowledged: <CIT>, <CIT>, <CIT> and <CIT>. <CIT> discloses a non-porous vessel capable of holding a fluid comprises an outer wall surface and an inner wall surface, the inner wall surface defining an interior chamber for holding the fluid; a filter having a perimeter, a first surface and a second surface, and fixedly attached around its entire perimeter to a portion of the inner wall surface of the nonporous vessel, thereby forming an integrated interior bag within the non-porous vessel; and a fitment attached to the outer wall of the non-porous vessel at a portion of the outer wall that is adjacent to the first surface of the integrated interior bag, the fitment forming a port configured to allow fluid to flow from the interior chamber through the integrated interior bag, through the filter, and out of the port.

In a broad independent aspect, a filter assembly for separating microcarriers from a fluid medium is provided, the filter assembly comprising:.

The collapsible container comprises a flexible bag.

In a subsidiary aspect, the flexible bag is made of one or more polymeric sheets.

In a subsidiary aspect, the container includes a hanging tab at a top portion thereof.

In a subsidiary aspect, the filter is expandable.

In a subsidiary aspect, the filter is flexible.

In a subsidiary aspect, the filter is comprised of a mesh material or a perforated polymeric sheet.

In a subsidiary aspect, the filter is coupled with the inlet port so that any fluid medium passing through the inlet port passes through the filter.

In a subsidiary aspect, the collapsible container has a floor and the filter is suspended above the floor.

In a subsidiary aspect, the filter comprises a porous sheet of flexible material that is secured to the collapsible container.

In a subsidiary aspect, the container is comprised of two discrete panels secured together, a portion of the filter being secured between the two panels.

In a further aspect a filter system with the filter assembly according to claim <NUM> is provided.

In a subsidiary aspect, the filter assembly further comprises an outlet port attached to the collapsible container, the outlet port having a fluid passageway extending therethrough such that the cultured solution can exit the sterile compartment therethrough.

In a subsidiary aspect, the filter is comprised of a material that is resiliently stretchable.

The filter inlet port is fluidly coupled with the filter port by a dip tube line.

In a subsidiary aspect, the plurality of sheets comprise a first sheet and a second sheet bounded together at their peripheries, the second sheet being comprised of the porous material, the first and second sheets bounding the inlet chamber.

In a subsidiary aspect, the plurality of sheets further comprises a third sheet having an opening extending therethrough, the third sheet being bounded to the first and second sheets at the periphery of the third sheet such that the second sheet is sandwiched between the first and third sheets at the periphery of the second sheet.

In a subsidiary aspect, the first sheet has an opening extending therethrough, and the plurality of sheets further comprises a third sheet, the third sheet being comprised of the porous material, the third sheet being bounded to the first sheet to cover the opening therein, the third sheet also bounding the inlet chamber.

In a subsidiary aspect, the perimeter edges of the first sheet are wrapped around the perimeter edges of the second sheet and bounded thereto.

In a subsidiary aspect, the filter system comprises:.

In a subsidiary aspect, the filter system further comprises a hanger removably coupling the container to the support housing so that the container is suspend within the chamber.

In a subsidiary aspect, the filter port is removably attached to the support housing.

In a subsidiary aspect, the filter system further comprises a clamp assembly that removably attaches the filter port to the support housing.

In a subsidiary aspect, the flexible bag is comprised of two polymeric panels that are welded together, the filter being secured within the weld.

In a subsidiary aspect, a filter system comprises:.

In a subsidiary aspect, the filter assembly further comprises an inlet port attached to the collapsible container, the inlet port having a fluid passageway extending therethrough such that the medium can pass therethrough and into the chamber.

In a further subsidiary aspect, a filter system comprises:.

In a further subsidiary aspect, the filter system further comprises a hanger removably coupling the container to the support housing so that the container is suspended within the chamber.

Various embodiments of the present invention will now be discussed with reference to the appended drawings. In the drawings, like numerals designate like elements. Furthermore, multiple instances of an element may each include separate letters appended to the element number. For example two instances of a particular element "<NUM>" may be labeled as "20a" and "20b". In that case, the element label may be used without an appended letter (e.g., "<NUM>") to generally refer to every instance of the element; while the element label will include an appended letter (e.g., "20a") to refer to a specific instance of the element.

As used in the specification and appended claims, directional terms, such as "top," "bottom," "left," "right," "up," "down," "upper," "lower," "proximal," "distal" and the like are used herein solely to indicate relative directions in viewing the drawings and are not intended to limit the scope of the claims in any way.

The present invention relates to various apparatuses and methods for effectively filtering microcarriers or other particulates out of a cell culture solution without clogging or otherwise impeding the flow of the solution away from the microcarriers.

<FIG> depicts a cell culturing system. In cell culturing system <NUM>, cells are grown within a biological container, such as bioreactor <NUM>. Bioreactor <NUM> can be a microgravity bioreactor, internally-stirred bioreactor, fluidized bed bioreactor, rocker bag bioreactor or any other type of bioreactor known in the art. Bioreactor <NUM> can also be a rigid tank reactor that needs to be sterilized between uses or a single use bioreactor that includes a disposable bag. Other types of bioreactors or other biological containers can alternatively be used, such as, e.g., a spinner flask. The cells are grown in a nutrient growth medium that can include a variety of different components. The components are typically dependent on the cell type and processing conditions. Growth mediums and related components are known in the art and are not discussed herein.

Microcarriers are added to the growth medium within the bioreactor so that anchorage-dependent cells can grow thereon. The microcarriers can be spherically shaped beads ranging between about <NUM> microns to about <NUM> microns in diameter. Other sizes can also be used. It is also appreciated that the microcarriers can have alternative shapes but typically have a maximum diameter in a range between about <NUM> microns to about <NUM> microns. The microcarriers have a density that allows them to be maintained in suspension with gentle stirring. For example, the microcarriers can also have a density of about <NUM>/cm<NUM> to about <NUM>/cm<NUM>. Other densities are also possible. The microcarriers can be made from a number of different materials including DEAE-dextran, glass, polystyrene plastic, acrylamide, and collagen. The different types of microcarriers can differ in their porosity, specific gravity, optical properties, presence of animal components, and surface chemistries. Surface chemistries can include extracellular matrix proteins, recombinant proteins, peptides, and positively or negatively charged molecules. The microcarrier materials, along with the different surface chemistries, can influence cellular behavior, including morphology, proliferation and adhesion.

During culturing, the cells grow on the surface of the microcarriers disposed within the mixture. Once the cell culturing process is completed, a chemical reagent, such as an enzyme, is added to the mixture, which includes the medium and the microcarriers suspended within the medium. The chemical reagent causes the cells to detach from the microcarriers so that the cells are freely suspended within the growth medium. The mixture is then removed from the bioreactor <NUM> and passed through a filter system <NUM>. Filter system <NUM> includes a filter assembly <NUM> that can be housed in an optional support housing <NUM>. The filter assembly <NUM> comprises a filter <NUM> disposed within a container <NUM>. Filter <NUM> separates the microcarriers from the cultured solution, which includes the growth medium and the detached cells, by allowing the cultured solution to pass therethrough while preventing the microcarriers from doing so. Container <NUM> can be substantially rigid or flexible and can be disposable, if desired.

<FIG> shows a perspective view of filter system <NUM> including support housing <NUM> and filter assembly <NUM>. Depicted in <FIG> is a cross sectional side view of filter assembly <NUM>. In part, filter assembly <NUM> includes container <NUM>, a filter port <NUM> coupled to container <NUM> and filter <NUM> coupled to filter port <NUM>. Filter assembly <NUM> can also include one or more inlet ports and an outlet ports through which fluid can flow into and out of container <NUM>, respectively, as described in more detail below. In one embodiment, container <NUM> comprises a flexible and collapsible body <NUM>, such as a flexible bag, having an interior surface <NUM> and an opposing exterior surface <NUM>. Interior surface <NUM> bounds a compartment <NUM>. More specifically, body <NUM> comprises a side wall <NUM> that, when body <NUM> is unfolded, has a substantially circular or polygonal transverse cross section that extends between a first end <NUM> and an opposing second end <NUM>. First end <NUM> terminates at a top end wall <NUM> while second end <NUM> terminates at a bottom end wall <NUM>.

Body <NUM> is comprised of a flexible, water impermeable material such as polyethylene or other polymeric sheets having a thickness in a range between about <NUM> to about <NUM> with about <NUM> to about <NUM> being more common. Other thicknesses can also be used. The material can be comprised of a single ply material or can comprise two or more layers which are either sealed together or separated to form a double wall container. Where the layers are sealed together, the material can comprise a laminated or extruded material. The laminated material comprises two or more separately formed layers that are subsequently secured together by an adhesive.

The extruded material comprises a single integral sheet that comprises two or more layers of different material that can be separated by a contact layer. All of the layers are simultaneously co-extruded. One example of an extruded material that can be used in the present invention is the HyQ CX3-<NUM> film available from HyClone Laboratories, Inc. out of Logan, Utah. The HyQ CX3-<NUM> film is a three-layer, <NUM> mil cast film produced in a cGMP facility. The outer layer is a polyester elastomer coextruded with an ultra-low density polyethylene product contact layer. Another example of an extruded material that can be used in the present invention is the HyQ CX5-<NUM> cast film also available from HyClone Laboratories, Inc. The HyQ CX5-<NUM> cast film comprises a polyester elastomer outer layer, an ultra-low density polyethylene contact layer, and an EVOH barrier layer disposed therebetween. In still another example, a multi-web film produced from three independent webs of blown film can be used. The two inner webs are each a <NUM> mil monolayer polyethylene film (which is referred to by HyClone as the HyQ BM1 film) while the outer barrier web is a <NUM> mil thick <NUM>-layer coextrusion film (which is referred to by HyClone as the HyQ BX6 film).

The material is approved for direct contact with living cells and is capable of maintaining a solution sterile. In one embodiment, the material can be sterilizable such as by ionizing radiation or other conventional techniques. Other examples of materials that can be used in different situations are disclosed in <CIT> and United States Patent Publication No. <CIT> which are hereby incorporated by specific reference.

In one embodiment, body <NUM> comprises a two-dimensional pillow style bag wherein two sheets of material are placed in overlapping relation and the two sheets are bounded together at their peripheries to form internal compartment <NUM>. Alternatively, a single sheet of material can be folded over and seamed around the periphery to form internal compartment <NUM>. In another embodiment, body <NUM> can be formed from a continuous tubular extrusion of polymeric material that is cut to length and is seamed closed at the ends. In still other embodiments, such as in the depicted embodiment, body <NUM> comprises a three-dimensional bag that not only has an annular side wall <NUM> but also a two dimensional top end wall <NUM> and a two dimensional bottom end wall <NUM>. Three dimensional containers can comprise a plurality of discrete panels, typically three or more, and more commonly four or six. Each panel can be substantially identical and can comprise a portion of the side wall, top end wall, and bottom end wall of the container. Corresponding perimeter edges of each panel can be seamed. The seams are typically formed using methods known in the art such as heat energies, RF energies, sonics, or other sealing energies.

In alternative embodiments, the panels can be formed in a variety of different patterns. Further disclosure with regard to one method of manufacturing three-dimensional bags is disclosed in United States Patent Publication No. <CIT>.

Although in the above discussed embodiment body <NUM> is in the form of a flexible bag, in alternative embodiments it is appreciated that body <NUM> can also comprise any form of collapsible container or semi-rigid container. Body <NUM> can also be transparent or opaque and can have ultraviolet light inhibitors incorporated therein.

It is appreciated that body <NUM> can be manufactured to have virtually any desired size, shape, and configuration. For example, body <NUM> can be formed having compartment <NUM> that is sized to hold in a range from about <NUM> liters to about <NUM>,<NUM> liters, with about <NUM> liters to about <NUM> liters and about <NUM> liters to about <NUM> liters being more common. Other volume sizes can also be used. Although body <NUM> can be any shape, in one embodiment body <NUM> is specifically configured to be substantially complementary to a first chamber <NUM> (<FIG>) of support housing <NUM>, as discussed below.

Continuing with <FIG>, one or more hanging tabs <NUM> can be mounted on top end wall <NUM> or the upper end of sidewall <NUM> to support the upper end of body <NUM> within support housing <NUM>, if used. For example, in the depicted embodiment a plurality of radially spaced apart hanging tabs <NUM> are positioned on top end wall <NUM> at or near the outer perimeter thereof. Each hanging tab <NUM> includes a first end <NUM> secured to body <NUM> and an opposing second end <NUM> through which an opening <NUM> is formed. As shown in <FIG>, when filter assembly <NUM> is positioned within support housing <NUM>, a hanger <NUM> can be received within a corresponding opening <NUM> of each hanging tab <NUM> to support container <NUM> within support housing <NUM>.

Hanging tabs <NUM> can be attached to body <NUM> or integrally formed therewith. Hanging tabs <NUM> can be made of the same material as body <NUM>, if desired. In embodiments in which body <NUM> is comprised of panels, hanging tabs <NUM> can be attached to body <NUM> by being welded between the panels. In other embodiments, hanging tabs <NUM> can be mounted on the outside of body <NUM> such as by welding or adhesion.

As shown in <FIG>, one or more inlet ports can be mounted on top end wall <NUM> of body <NUM>. In the depicted embodiment, an inlet port <NUM> is shown. Inlet port <NUM> comprises a barbed tubular stem <NUM> having a flange <NUM> radially encircling and outwardly projecting therefrom. Inlet port <NUM> bounds a fluid passageway <NUM> that extends therethrough. During assembly, a hole is made through top end wall <NUM> for the port. The stem <NUM> of port <NUM> is then passed through the hole until flange <NUM> rests against top end wall <NUM>. Conventional welding or other sealing techniques are then used to seal each flange <NUM> to top end wall <NUM>. During use, stem <NUM> can be selectively coupled with a tube or container for delivering material into and/or out of compartment <NUM>.

Mounted on bottom end wall <NUM> of body <NUM> is an outlet port <NUM>. Similar to inlet port <NUM>, outlet port <NUM> comprises a barbed tubular stem <NUM> having a flange <NUM> radially encircling and outwardly projecting therefrom. Outlet port bounds a fluid passageway <NUM> that extends therethrough. As with inlet ports <NUM>, during assembly a hole is formed in bottom end wall <NUM>. Outlet port <NUM> is seated within the hole so that flange <NUM> rests against bottom end wall <NUM>. Again, conventional welding or other sealing technique is then used to seal flange <NUM> to bottom end wall <NUM>. During use, stem <NUM> is selectively coupled with an outlet tube for delivering material out of compartment <NUM>.

It is appreciated that any number of inlet ports <NUM> or outlet ports <NUM> can be formed on body <NUM> and that a variety of different types and sizes of ports can be used depending on the type of material to be dispensed into compartment <NUM> and how the material is to be dispensed therefrom. The ports <NUM> and <NUM> can also be located at different locations on body <NUM> such as side wall <NUM>.

Filter port <NUM> also functions as an inlet port. Specifically filter port <NUM> includes a flange <NUM> mounted to top end wall <NUM>. A tubular first stem <NUM> upwardly projects from one side of flange <NUM> and has an annular barb formed on the end thereof. A tubular second stem <NUM> projects from an opposing side of flange <NUM> so as to extend downward into compartment <NUM>. A support flange <NUM> encircles and radially outwardly projects from the end of second stem <NUM>. Turning to <FIG>, filter port <NUM> has an inside surface <NUM> that bounds a fluid passageway <NUM> extending therethrough, i.e., fluid passageway <NUM> extends through first stem <NUM>, flange <NUM>, second stem <NUM> and support flange <NUM>. Filter port <NUM> can be integrally formed as a single unitary structure or can comprise two or more parts secured together. Support flange <NUM> has a lower face <NUM> and an opposing upper face <NUM> that both radially extend to an outside face <NUM>. An annular groove <NUM> can be recessed on outside face <NUM> for mounting filter <NUM> thereto, as discussed below.

Filter <NUM> comprises a body <NUM> having an interior surface <NUM> that bounds a compartment <NUM> and an opposing exterior surface <NUM>. A mouth <NUM> is formed on body <NUM> so as to communicate with compartment <NUM>. In one embodiment, filter <NUM> is flexible and can be in the form of a porous bag or sock. Filter <NUM> is attached to filter port <NUM> by inserting support flange <NUM> within mouth <NUM>. A connector <NUM> such as a clamp, cable tie crimp ring, strap, or the like is then positioned over filter <NUM> and tightened so as to secure filter <NUM> within groove <NUM>. In alternative embodiments, it is appreciated that other conventional methods can be used to secure filter <NUM> to filter port <NUM>. For example, filter <NUM> can be secured to filter port <NUM> by welding, adhesive or the like. In other embodiments, support flange <NUM> can be eliminated and filter <NUM> can be attached directly to second stem <NUM>. In still other embodiments, support flange <NUM> and second stem <NUM> can both be eliminated and filter <NUM> can be attached to an extended version of flange <NUM>.

Lower surface <NUM> of support flange <NUM> and interior surface <NUM> of filter <NUM> together bound an inlet chamber <NUM> that is fluidly coupled with fluid passageway <NUM>. As discussed below in greater detail, during use a mixture of cultured solution and associated microcarriers can be delivered to inlet chamber <NUM> through filter port <NUM>. Filter <NUM> comprises a material that will allow the cultured solution to pass therethrough while preventing the microcarriers from passing therethrough. As such, the microcarrier are collected within inlet chamber <NUM> of body <NUM>. Filter <NUM> can be comprised of a porous material, such as a mesh, netting, perforated sheets, lattice type of material, or any other material that will allow the cultured solution to pass therethrough while preventing the associated microcarriers from passing therethrough. To enable the cells to pass therethrough but prevent the microcarriers from passing therethrough, filter <NUM> is typically made of a material, having pores in the size of about <NUM> microns to about <NUM> microns, with about <NUM> microns to about <NUM> microns being common. If desired, filter <NUM> can be expandable and/or resiliently stretchable. Examples of materials that can be used for filter <NUM> include polyester (PET), polyamide (PA), polypropylene (PP), and polyetheretherketone (PEEK). Other materials can also be used.

In alternative embodiments, it is appreciated that part or all of filter <NUM> can be rigid or semi-rigid. For example, filter <NUM> can comprise body <NUM> formed from a porous flexible material while a rigid ring is mounted to body <NUM> and encircles mouth <NUM>. The rigid ring could then be used to secure filter <NUM> to filter port <NUM> such as by threaded connection, bayonet connection, snap fit connection, press fit engagement, crimped engagement or the like. In other embodiments, filter <NUM> can be comprised of a rigid material. For example, filter <NUM> can be molded from a plastic, metal, or composite material, that has holes formed therethrough through which the cultured fluid can pass but the microcarriers cannot.

Returning to <FIG>, as a result of filter <NUM> being coupled with filter port <NUM> which is attached to top end wall <NUM>, filter <NUM> is suspended down into compartment <NUM>. When disposed within compartment <NUM>, filter <NUM> essentially divides compartment <NUM> into two chambers - inlet chamber <NUM> of filter <NUM>, and an outlet chamber <NUM>. Outlet chamber <NUM> is the portion of compartment <NUM> external to inlet chamber <NUM> and fluid passageway <NUM>. As such, fluid flows from inlet chamber <NUM> to outlet chamber <NUM> through filter <NUM>.

In one embodiment, filter <NUM> is sized and positioned so as to be suspended above bottom end wall <NUM> of container <NUM> and away from sidewall <NUM>, as shown in <FIG>. In some embodiments it can be desirable to keep filter <NUM> away from bottom end wall <NUM> and side wall <NUM> since contacting filter <NUM> against a structure can cause blocking of that portion of filter <NUM> which can decrease fluid flow through filter <NUM>. In some embodiments, filter <NUM> remains above bottom end wall <NUM> during use so as to not contact bottom end wall <NUM>. In other embodiments, filter <NUM> may contact bottom end wall <NUM> and/or side wall <NUM> such as after a portion of the microcarriers have been collected.

If an expandable material is used for filter <NUM>, the weight of the microcarriers may cause filter <NUM> to expand downward and outward as more microcarriers are received, as discussed below. However, by being suspended from top end wall <NUM>, filter <NUM> can in some embodiments be configured to remain above bottom end wall <NUM> even when expanded, as discussed in more detail below.

Support housing <NUM> can be used to support filter assembly <NUM> or any of the filter assemblies discussed herein. This can be especially helpful if container <NUM> is flexible, as support housing <NUM> can provide rigid support for container <NUM>. Returning to <FIG>, support housing <NUM> generally includes a substantially rigid receptacle <NUM> seated on a dolly <NUM>. As depicted, receptacle <NUM> is configured to receive and support filter assembly <NUM>.

Turning to <FIG> and <FIG>, receptacle <NUM> comprises a substantially cylindrical side wall <NUM> that extends from an upper end <NUM> to an opposing lower end <NUM>. As depicted in <FIG>, receptacle <NUM> includes a floor <NUM> formed inside of receptacle <NUM> at a position between upper end <NUM> and lower end <NUM>. Floor <NUM> has a substantially frustoconical configuration. More specifically, floor <NUM> has a frustoconical portion <NUM> with a top surface <NUM> that extends between an inner edge <NUM> and an opposing outer edge <NUM>. Floor <NUM> also includes a flat base portion <NUM> inwardly extending from frustoconical portion <NUM>. Base portion <NUM> bounds a central opening <NUM> extending through floor <NUM>. Outer edge <NUM> is integrally formed with or is otherwise connected to side wall <NUM>. The slope of floor <NUM> functions in part as a funnel to direct all material toward central opening <NUM>. In alternative embodiments, floor <NUM> can be flat, cupped, irregular, or other desired configurations.

Side wall <NUM> of receptacle <NUM> has an interior surface <NUM> disposed above floor <NUM>. Interior surface <NUM> and floor <NUM> bound first chamber <NUM> formed in upper end <NUM> of receptacle <NUM>. First chamber <NUM> is sized to receive container <NUM> and can thus have a corresponding size. Depicted in <FIG>, upper end <NUM> of receptacle <NUM> terminates at an upper edge <NUM> that bounds an opening <NUM> to first chamber <NUM>.

As shown in <FIG>, an optional annular lid <NUM> can be removably disposed over upper edge <NUM> so as to selectively close opening <NUM>. Clamps <NUM> can be used to selectively secure lid <NUM> to receptacle <NUM>. Lid <NUM> can include one or more holes <NUM> extending therethrough. Holes <NUM> can be configured to align with ports <NUM> and <NUM> of container <NUM> so that inlet tubes can extend therethrough to attach to ports <NUM> and <NUM> and pass fluid into filter assembly <NUM>.

As previously mentioned, one or more hangers <NUM> can be secured to lid <NUM> or sidewall <NUM> of receptacle <NUM> at or near upper edge <NUM> to receive the corresponding hanging tabs <NUM> of filter assembly <NUM>. For example, as shown in <FIG>, hangers <NUM> can be in the form of hooks positioned on interior surface <NUM> to receive hanging tabs <NUM> positioned on container <NUM>, as shown in <FIG>. As shown in <FIG>, each hanger <NUM> is positioned on interior surface <NUM> so as to correspond to the position of one of the hanging tabs <NUM> when filter assembly <NUM> is positioned within first chamber <NUM>. Hangers <NUM> can be attached to receptacle <NUM> by using screws, adhesive, welding or other known attachment methods.

When it is desired to remove filter assembly <NUM> from support housing <NUM>, hanging tabs <NUM> can simply be disconnected from hangers <NUM> to allow filter assembly <NUM> to be removed. It is appreciated that hangers <NUM> can come in a variety of different forms. For example, hangers <NUM> can comprise hook that connect to hanging tabs <NUM> and then catches directly onto edge <NUM> of receptacle <NUM> for supporting filter assembly <NUM>. In this embodiment, hangers are not fixed to receptacle <NUM>. In still other embodiments, hangers <NUM> can comprise hooks or other types of projections or fasteners that are mounted on the exterior surface of sidewall <NUM>. In this embodiment, hanging tabs <NUM> can pass over edge <NUM> and then connect to hangers <NUM>.

Depicted in <FIG> is another alternative embodiment for the hangers. Specifically, a retention ring <NUM> is used for supporting container <NUM> within first chamber <NUM> of receptacle <NUM>. Retention ring <NUM> comprises a substantially C-shaped ring body <NUM> that terminates at opposing ends having flanges 544A and 544B formed thereat. A fastener <NUM> extends through flanges 544A and B and can be used for selectively drawing and securing flanges 544A and B together. In one embodiment, fastener <NUM> can comprise a bolt and nut assembly. In alternative embodiments, fastener <NUM> can comprise a clamp, latch, or any other conventional fastener that achieves the desired objective.

Ring body <NUM> is typically in the form of a narrow band having an inside face <NUM> and an opposing outside face <NUM>. A plurality of spaced apart hangers <NUM> are mounted on inside face <NUM> of ring body <NUM>. In one embodiment, each hanger <NUM> comprises a elongated pin having a first end <NUM> that is secured, such as by welding, at a central location on inside face <NUM>. Each pin also comprises an opposing second end <NUM> that projects up above ring body <NUM>. If desired, second end <NUM> of each pin can be rounded. Although not required, in one embodiment a plurality of spaced apart notches <NUM> are recessed on the bottom edge of ring body <NUM> such that the top of each notch <NUM> is disposed adjacent to first end <NUM> of a corresponding hanger <NUM>.

During use, fastener <NUM> is loosened so as to expand the size of ring body <NUM>. Ring body <NUM> is then positioned on upper end <NUM> of receptacle <NUM> so that ring body <NUM> encircles the exterior surface of side wall <NUM> at upper end <NUM>. In this configuration, first end <NUM> of each hanger <NUM> rests on top of upper edge <NUM> of side wall <NUM> so that retention ring <NUM> is properly positioned. If desired, a flange can be formed at first end <NUM> of each hanger <NUM> for receiving upper edge <NUM>. Notches <NUM> permit a visual inspection to ensure that ring body <NUM> is properly seated. Fastener <NUM> is then used to clamp retention ring <NUM> on side wall <NUM>. As container <NUM> (<FIG>) is inserted within first chamber <NUM>, second end <NUM> of each hanger <NUM> is passed through opening <NUM> of a corresponding hanging tab <NUM> (<FIG>) so that container <NUM> is supported within first chamber <NUM>.

In still other embodiments hangers <NUM> can be in the form of microhook and loop systems (commonly known as VELCRO), threaded connections, clamps, or the like that connect hanging tabs <NUM> to receptacle <NUM>.

As shown in <FIG>, side wall <NUM> also has an interior surface <NUM> formed below floor <NUM>. Interior surface <NUM> and floor <NUM> bound a second chamber <NUM> disposed at lower end <NUM> of receptacle <NUM>. An access port <NUM> extends through side wall <NUM> at lower end <NUM> of receptacle <NUM> so as to provide side access to second chamber <NUM>. In alternative embodiments, the portion of side wall <NUM> extending below floor <NUM> can be replaced with one or more spaced-apart legs or other supports that elevate floor <NUM> off of the ground, dolly <NUM>, or other surface on which receptacle <NUM> rests.

In the embodiment depicted, receptacle <NUM> comprises a barrel molded from a polymeric material. In alternative embodiments, receptacle <NUM> can be comprised of metal, fiberglass, composites, or any other desired material. Furthermore, although receptacle <NUM> is shown as having a substantially cylindrical configuration, receptacle <NUM> can be substantially boxed shaped or have a transverse configuration that is polygonal, elliptical, irregular, or any other desired configuration.

As depicted in <FIG>, dolly <NUM> comprises a frame <NUM> having a plurality of wheels <NUM> mounted thereon. Dolly <NUM> enables easy movement of receptacle <NUM>. In alternative embodiments where it is not necessary or desired to move receptacle <NUM>, wheels <NUM> and/or frame <NUM> can be eliminated. In this regard, receptacle <NUM> can sit on a ground surface or any other desired structure. As shown in <FIG>, lower end <NUM> of receptacle <NUM> is received on dolly <NUM> so as to be stably supported thereby.

Before use, filter assembly <NUM> can be positioned within first chamber <NUM> of receptacle <NUM> so that outlet port <NUM> can be received within central opening <NUM> extending through floor <NUM> of receptacle <NUM>, as depicted in <FIG>.

It is typically desirable that when filter assembly <NUM> is received within first chamber <NUM>, container <NUM> is at least generally uniformly supported by floor <NUM> and side wall <NUM> of receptacle <NUM> when container <NUM> is at least partially filled with a fluid. Having at least general uniform support of container <NUM> by receptacle <NUM> helps to preclude failure of container <NUM> by hydraulic forces applied to container <NUM> when filled with a solution.

Hanging tabs <NUM> disposed on top end wall <NUM> are looped over hangers <NUM> disposed on interior surface <NUM> of receptacle <NUM> to suspend container <NUM> within first chamber <NUM>. As such, container <NUM> may not extend all the way down to floor <NUM> until fluid is introduced into container <NUM>. Before container <NUM> is disposed within first chamber <NUM>, an outlet tube <NUM> can be connected to outlet port <NUM>. Outlet tube <NUM> extends through central opening <NUM> and can extend out from support housing <NUM> through access port <NUM>.

As noted above, filter <NUM> is suspended from top end wall <NUM> of container <NUM> by virtue of its coupling with filter port <NUM>. Because filter <NUM> is indirectly attached to top end wall <NUM>, filter <NUM> is generally suspended above bottom end wall <NUM> of container, as shown in <FIG>.

An inlet tube <NUM> is coupled with first stem <NUM> of filter port <NUM>. Either before or after filter assembly <NUM> has been positioned within first chamber <NUM>, inlet tube <NUM> can be coupled in a sterile fashion with bioreactor <NUM> (<FIG>). During use, a mixture of the cultured solution and the associated microcarriers from bioreactor <NUM> is introduced into inlet chamber <NUM> of filter assembly <NUM> through inlet tube <NUM>. The cultured solution of the mixture, including the detached cells, passes through filter <NUM> and into outlet chamber <NUM>.

More specifically, the mixture passes through fluid passageway <NUM> in filter port <NUM> and is received by inlet chamber <NUM> of filter <NUM>, as depicted in <FIG>. As shown in <FIG>, as the mixture is first received within inlet chamber <NUM>, as denoted by arrow <NUM>, inlet chamber <NUM> is completely or mostly devoid of microcarriers and the cultured solution can freely pass through filter <NUM> through the sides and bottom thereof, as indicated by arrows <NUM>. As shown in <FIG>, as more mixture flows into inlet chamber <NUM>, the microcarriers (shown as a group of beads <NUM>) within the mixture are retained and begin to accumulate at the bottom of inlet chamber <NUM>. The cultured solution continues to pass through filter <NUM>. However, the majority of the fluid passes out through the side portion of filter <NUM> that is above the accumulated microcarriers, as shown by arrows <NUM> and <NUM> in <FIG>. This is because the accumulated microcarriers at least partially block the flow of fluid through the portion of filter <NUM> that they rest against. Thus, the configuration of filter <NUM> permits an efficient collection of microcarriers while still permitting a free flow of cultured solution through filter <NUM>.

Filter <NUM> is typically sized so that all of the microcarriers from bioreactor <NUM> can be collected within inlet chamber <NUM> while still allowing a portion of filter <NUM> to be unobstructed by microcarriers so that the cultured solution can freely pass therethrough. Alternatively, a filter assembly <NUM> can be used until inlet chamber <NUM> is sufficiently filled with microcarriers that the cultured fluid can no longer pass through filter <NUM> as a desired processing rate. Filter assembly <NUM> can then be replaced with a new filter assembly <NUM> and the process continued.

If an expandable material is used for filter <NUM>, the weight of the microcarriers can cause filter <NUM> to expand downward and outward, as depicted in <FIG>. This expansion can cause filter <NUM> to become more elongate, thereby increasing the surface area of filter <NUM> and allowing more cultured solution to flow through the sides of filter <NUM> as to enable more microcarriers to be retained within inlet chamber <NUM>.

After the cultured solution passes through filter <NUM>, the cultured solution can either be retained within outlet chamber <NUM> or can pass directly out of container <NUM> through outlet port <NUM> and outlet tube <NUM>. Once all of the cultured solution has been processed through filter assembly <NUM>, filter assembly <NUM> can be removed from support housing <NUM> and discarded with the microcarriers contained therein. Alternatively, filter assembly <NUM> can be cut open and the microcarriers removed and recycled for further use. By forming filter assembly <NUM> from a disposable container and filter, the inventive system eliminates the need for cleaning or sterilizing the filtering system between different batches of culturing solution.

In some systems, the weight of the microcarriers combined with the force caused by the downward motion of the incoming mixture can cause a strain on container <NUM> where filter port <NUM> attaches to top end wall <NUM>. To alleviate this strain between filter port <NUM> and top end wall <NUM>, filter port <NUM> can also be directly attached to receptacle <NUM> instead of or in conjunction with the hanging tabs and hangers, discussed above. For example, in the embodiment shown in <FIG>, a hanging flange <NUM> is attached to or is integrally formed with stem <NUM> of filter port <NUM>. Hanging flange <NUM> outwardly projects from stem <NUM> above flange <NUM> so that hanging flange <NUM> will be positioned outside of compartment <NUM> when filter port <NUM> has been attached to top end wall <NUM>. Hanging flange <NUM> has a top surface <NUM> and an opposing bottom surface <NUM> and bounds an opening <NUM> extending therethrough. Similar to hanging tabs <NUM>, discussed previously, opening <NUM> of hanging flange <NUM> can be looped over one of hangers <NUM> disposed on receptacle <NUM> to suspend filter port <NUM> and filter <NUM> from the top end of receptacle <NUM>. To position opening <NUM> of hanging flange <NUM> adjacent to a hanger <NUM>, filter port <NUM> can be positioned adjacent to the perimeter edge of top end wall <NUM>, as shown in the depicted embodiment.

All or portions of hanging flange <NUM> can be flexible or substantially rigid. If hanging flange <NUM> is substantially rigid, the portion of hanging flange <NUM> that includes opening <NUM> can be shaped to form an angle with respect to the rest of second flange <NUM>, as shown in the depicted embodiment, to more easily facilitate the attachment of hanging flange <NUM> to hanger <NUM> and to help keep filter <NUM> vertical. It is appreciated that all of the other methods as discussed above for securing hanging tabs <NUM> to receptacle <NUM> can also be used to secure hanging flange <NUM> to receptacle <NUM>.

In one embodiment, the hanging flange <NUM> is replaced by an attachment device that is removable and reusable. For example, as shown in <FIG>, the hanging flange <NUM> can be replaced by a clamp assembly <NUM> that removably attaches to stem <NUM>. Clamp assembly <NUM> includes a pair of mating arms <NUM> and <NUM> that rotate about a hinge <NUM> positioned at one end <NUM> of the pair of arms. Hinge <NUM> includes a tubular hinge pin <NUM> that bounds an opening <NUM>. At the other end <NUM> of arms <NUM>/<NUM> is a securing mechanism, such as a screw assembly <NUM>, to tighten arms <NUM> and <NUM> together around stem <NUM>. During use, opening <NUM> is advanced over hanger <NUM> so that hanger <NUM> supports filter port <NUM> and attached container <NUM>. If desired, hanger <NUM> can have substantially hard (i.e., about <NUM> degree) angles to facilitate keeping inlet port <NUM> and filter <NUM> in a generally vertical orientation. It is appreciated that opening <NUM> need not be located within hinge pin <NUM> but and otherwise be formed on clamp assembly <NUM>.

In another embodiment, a removable attachment device can be used with a modified hanging flange and hanger. For example, as shown in <FIG>, hanger <NUM> can be replaced by a hanger <NUM> that is also secured to interior surface <NUM> of sidewall <NUM> at upper end <NUM> of receptacle <NUM>. Hanger <NUM> includes a flange <NUM> attached to and projecting from sidewall <NUM> and a substantially C-shaped retainer <NUM> disposed at the end thereof. Retainer <NUM> includes a stem <NUM> and a flange <NUM> radially outwardly projecting therefrom. Both stem <NUM> and flange <NUM> have a substantially C-shaped configuration.

Turning to <FIG>, a hanging flange <NUM> is integrally formed with stem <NUM> of inlet port <NUM>. Hanging flange <NUM> is similar to hanging flange <NUM>, discussed above, except that hanging flange <NUM> may omit openings extending therethrough, if desired, and is typically flat. Hanging flange <NUM> radially encircles and outwardly projects from stem <NUM> above flange <NUM>. Hanging flange <NUM> has a top surface <NUM> and an opposing bottom surface <NUM>. For receptacle <NUM> to support filter port <NUM>, filter port <NUM> can be positioned so that stem <NUM> extends through stem <NUM> of support hanger <NUM> and the bottom surface <NUM> of hanging flange <NUM> rests upon flange <NUM> of hanger <NUM>. In this position, hanger <NUM> can provide the desired support for container <NUM>.

To secure filter port <NUM> to hanger <NUM>, a clamp assembly <NUM> can be used. Clamp assembly <NUM> can be similar to clamp assembly <NUM>, discussed above, with a few differences. As shown in <FIG>, clamp assembly <NUM> includes a pair of mating arms <NUM> and <NUM> that rotate about a hinge <NUM> positioned at one end <NUM> of the pair of arms. At the other end <NUM> of the arms is a securing mechanism, such as a screw assembly <NUM>, to tighten arms <NUM> and <NUM> together. An annular channel <NUM> is formed on the inside surface of arms <NUM> and <NUM>.

Returning to <FIG>, to secure filter port <NUM> to support <NUM>, arms <NUM> and <NUM> (collectively denoted as <NUM>) are positioned around flange <NUM> and hanging flange <NUM> so that when clamp assembly <NUM> is closed and tightened, these structures are received within annular channel <NUM> and securely held together. A gasket or the like can also be positioned within annular channel <NUM>, if desired, to form a more secure connection between clamp assembly <NUM> and flange <NUM> and hanging flange <NUM>. Other types of securing methods and devices can alternatively be used to secure filter to receptacle <NUM>.

<FIG> depicts another embodiment of a filter assembly <NUM>. Like elements between filter assembly <NUM> and filter assembly <NUM> are identified by like reference characters. Similar to filter assembly <NUM>, filter assembly <NUM> comprises a filter <NUM> disposed within container <NUM> and attached thereto using a filter port <NUM>. However, instead of being directly attached to filter port <NUM>, filter <NUM> includes an inlet port <NUM> that is attached to filter port <NUM> using a dip tube line <NUM>.

Similar to filter port <NUM>, filter port <NUM> includes barbed first stem <NUM> upwardly projecting from a top side of flange <NUM>. A barbed second stem <NUM> projects from the bottom side of flange <NUM> so as to extend downward into compartment <NUM>. Second stem <NUM> is generally similar to first stem <NUM> except that second stem <NUM> extends in the opposite direction from flange <NUM>. Filter port <NUM> has an inside surface <NUM> that bounds a fluid passageway <NUM> extending therethrough, i.e., fluid passageway <NUM> extends through first stem <NUM>, flange <NUM>, and second stem <NUM>. Filter port <NUM> can be integrally formed as a single unitary structure or can comprise two or more parts secured together.

Turning to <FIG>, filter <NUM> comprises a two-dimensional pillow style bag <NUM> wherein two sheets <NUM> and <NUM> of material are placed in overlapping relation and the two sheets are bounded together at their peripheries to form an internal chamber <NUM>.

Turning to <FIG> in conjunction with <FIG>, sheet <NUM> has an interior surface <NUM> and an opposing exterior surface <NUM> extending to a perimeter edge <NUM>. Sheet <NUM> is comprised of a flexible material such as polyethylene or other polymeric sheets, similar to body <NUM> of container <NUM>. The material can be comprised of a single ply material or can comprise two or more layers which are either sealed together or separated to form a double wall container. Where the layers are sealed together, the material can comprise a laminated or extruded material. The laminated material comprises two or more separately formed layers that are subsequently secured together by an adhesive. Sheet <NUM> can be comprised of the same type of materials as discussed above with regard to body <NUM> of container <NUM>. In one embodiment, sheet <NUM> is comprised of the same material as body <NUM>. Although shown in the depicted embodiment as being substantially circular, it is appreciated that sheet <NUM> can have virtually any desired shape. Similarly, it is appreciated that sheet <NUM> can have virtually any desired size.

A hole <NUM> is formed in sheet <NUM> so as to extend therethrough between interior and exterior surfaces <NUM> and <NUM>. Hole <NUM> is sized so as to be able to receive inlet port <NUM>. Although hole <NUM> is shown in the depicted embodiment as being substantially centered on sheet <NUM>, this is not required. Hole <NUM> can be positioned anywhere on sheet <NUM> and can be any size that will accommodate inlet port <NUM>.

Sheet <NUM> has an interior surface <NUM> and an opposing exterior surface <NUM> extending to a perimeter edge <NUM>. Sheet <NUM> is comprised of a flexible porous material that allows the cultured solution to pass through, yet prevents microcarriers from passing through. For example, sheet <NUM> can be comprised of a mesh material made of a polymeric material, such as those materials discussed above with respect to filter <NUM>. Other polymeric and non-polymeric materials can also be used. Furthermore, pore size ranges of the mesh can be similar to those discussed above with respect to filter <NUM>. Sheet <NUM> can be expandable and/or resiliently stretchable, if desired. Sheet <NUM> is generally sized and shaped to match the size and shape of sheet <NUM>, although this is not required.

Inlet port <NUM> is similar to inlet ports <NUM> positioned on body <NUM> (see <FIG>). As such, as shown in <FIG>, inlet port <NUM> comprises a barbed tubular stem <NUM> having a flange <NUM> radially encircling and outwardly projecting therefrom. Inlet port <NUM> bounds a fluid passageway <NUM> that extends therethrough. During assembly, hole <NUM> is made through sheet <NUM> for the port. Stem <NUM> of inlet port <NUM> is then passed up through hole <NUM> until flange <NUM> rests against interior surface <NUM> of sheet <NUM>. Conventional welding or other sealing techniques are then used to seal flange <NUM> to sheet <NUM>.

After inlet port <NUM> has been secured to sheet <NUM>, interior surfaces <NUM> and <NUM> of sheets <NUM> and <NUM> are positioned against each other, as shown in <FIG>, and corresponding perimeter edges <NUM> and <NUM> are attached or secured together using heat energies, RF energies, sonics, or other sealing energies. Adhesives or other types of securing or attaching devices or methods can also be used. Dashed lines <NUM> of <FIG> depicts the perimeter portions of sheets <NUM> and <NUM> that are secured together during assembly. When secured, inside surfaces <NUM> and <NUM> together bound compartment <NUM>, with material being deliverable thereinto via inlet port <NUM>.

Returning to <FIG>, once filter <NUM> has been assembled, filter <NUM> can be positioned within container <NUM>. That is, during assembly of filter assembly <NUM>, stem <NUM> of filter <NUM> can be fluidly coupled with second stem <NUM> of filter port <NUM> using dip tube line <NUM>. Container <NUM> can then be sealed closed.

Similar to filter assembly <NUM>, filter assembly <NUM> can be positioned before use within first chamber <NUM> of receptacle <NUM>, and the top of container <NUM> can be attached to receptacle <NUM> using hanging tabs or other hanging elements. Also similar to filter assembly <NUM>, outlet tube <NUM> can be connected to outlet port <NUM> and extended through central opening <NUM> and out from support housing <NUM> through access port <NUM>.

During use, inlet tube <NUM> is coupled with bioreactor <NUM> (<FIG>) so that a mixture of cultured solution and associated microcarriers can be introduced into inlet chamber <NUM>. The cultured solution portion of the mixture passes through filter <NUM> and into outlet chamber <NUM>, where the fluid can collect or exit container <NUM> through outlet port <NUM> and outlet tube <NUM>. Filter <NUM> causes the microcarriers to be retained within inlet chamber <NUM> to be discarded or recycled for further use.

More specifically, the mixture passes through filter port <NUM> and dip tube line <NUM> to arrive at filter <NUM>. The mixture passes through inlet port <NUM> and is received by inlet chamber <NUM> through fluid passageway <NUM>, as depicted in <FIG>. As shown in <FIG>, as the mixture is first received within inlet chamber <NUM> as denoted by arrow <NUM>, inlet chamber <NUM> is completely or mostly devoid of microcarriers and the cultured fluid can pass through porous sheet <NUM> through the bottom thereof, as indicated by arrows <NUM>. Filter bag <NUM> can be substantially flat, as there is no weight to push it downward.

As shown in <FIG>, as more mixture flows into inlet chamber <NUM>, the microcarriers <NUM> within the mixture are retained and begin to accumulate at the bottom of inlet chamber <NUM>. The weight of the microcarriers <NUM> can cause filter <NUM> to elongate and extend further downward. The cultured solution continues to pass through porous sheet <NUM>. However, the majority of the fluid passes out through the side portions of porous sheet <NUM> that is above the accumulated microcarriers, as shown by arrows <NUM>.

As shown in <FIG>, as more microcarriers <NUM> continue to accumulate at the bottom portion of filter <NUM>, the weight of the microcarriers may cause filter <NUM> to further elongate and fluid can continue to flow through the upper portion of sheet <NUM> not covered by microcarriers, as denoted by arrows <NUM>. If an expandable material is used for porous sheet <NUM>, the weight of the microcarriers can cause porous sheet <NUM> to expand further downward. This expansion can increase the surface area of porous sheet <NUM> which can allow for more cultured solution to flow through the sides of porous sheet <NUM> and more microcarriers can be retained.

<FIG> depict another embodiment of a filter <NUM> based on filter <NUM> but using an alternative filter sheet configuration. The sheets of filter <NUM> are depicted as being rectangular. However, as discussed above, this is exemplary only and the sheets can be of any size and shape. Similar to filter <NUM>, filter <NUM> also includes flexible sheet <NUM> and porous sheet <NUM>. However, filter <NUM> also includes a picture-frame sheet <NUM> positioned against exterior surface <NUM> of porous sheet <NUM> so as to sandwich the edges of porous sheet <NUM> between sheets <NUM> and <NUM>, as particularly shown in <FIG>. Sheet <NUM> has an interior surface <NUM> and an opposing exterior surface <NUM>. Sheet <NUM> bounds an opening <NUM> extending through sheet <NUM> between interior and exterior surfaces <NUM> and <NUM>. Sheet <NUM> can be comprised of similar materials as sheet <NUM> and can be used to aid in securing porous sheet <NUM> to sheet <NUM>. That is, sheet <NUM> may be useful if the porous material does not form a secure attachment to sheet <NUM>. Sheet <NUM> can provide a better attachment to sheet <NUM> and the edges of sheet <NUM> can be better attached due to its being sandwiched between sheets <NUM> and <NUM>.

In an alternative embodiment, shown in <FIG>, sheet <NUM> can be omitted and sheet <NUM> can be sized to be larger than sheet <NUM>. The portion of perimeter edge <NUM> of sheet <NUM> that extends beyond perimeter edge <NUM> of sheet <NUM> can be folded over perimeter edge <NUM> so as to rest against exterior surface <NUM> of porous sheet <NUM> and form the picture-frame.

<FIG> and <FIG> depict another embodiment of a filter <NUM> based on filter <NUM> but using another alternative filter sheet configuration. Filter <NUM> is similar to filter <NUM>, except that sheet <NUM> is replaced with a sheet <NUM> that bounds an opening <NUM> extending therethrough. To prevent microcarriers from passing through opening <NUM>, another porous sheet <NUM> is also included to go along with porous sheet <NUM>. Sheet <NUM> is sized similar to opening <NUM> and is secured to the interior surface of sheet <NUM>. Porous sheet <NUM> does not cover hole <NUM> so that the cultured solution can pass through hole <NUM> and into internal chamber <NUM>, which is now bounded by porous sheet <NUM> as well as sheets <NUM> and <NUM>, as particularly shown in <FIG>. This embodiment provides more surface area for the solution to pass through than filters <NUM> or <NUM>, as solution can also pass through porous sheet <NUM> covering opening <NUM> on top sheet <NUM>. As shown in the depicted embodiment, hole <NUM> can be positioned near the perimeter edge of sheet <NUM> to allow opening <NUM> to have a larger surface area, if desired.

As with filter <NUM>, picture frame sheet <NUM> can alternatively be omitted and sheet <NUM> can be sized to be larger than sheets <NUM> and <NUM>. The portion of the perimeter edge of sheet <NUM> that extends beyond perimeter edge <NUM> of sheet <NUM> can be folded over perimeter edge <NUM> so as to rest against exterior surface <NUM> of porous sheet <NUM> and form the picture-frame in a manner similar to that discussed above with regard to filter <NUM>.

As with filter port <NUM>, filter port <NUM> can also be directly attached to receptacle <NUM> instead of or in conjunction with the hanging tabs and hangers, as discussed above with reference to <FIG> and <FIG>. It is appreciated that the filter embodiments shown in <FIG> are exemplary only and that other two-dimensional pillow style bags can also be used. It is also appreciated that instead of using a dip tube line <NUM> to attach filter port <NUM> to inlet port <NUM>, a single port can be used to directly attach top sheet <NUM> or <NUM> to body <NUM> of container <NUM>.

<FIG> depicts another embodiment of a filter assembly <NUM>. Like elements between filter assembly <NUM> and filter assembly <NUM> are identified by like reference characters. Filter assembly <NUM> includes a filter <NUM> that attaches directly or indirectly to the body <NUM> of container <NUM> to divide compartment <NUM> into an inlet chamber <NUM> and an outlet chamber <NUM>. Filter <NUM> comprises a sheet of a porous material that will allow the cultured solution to pass therethrough but will prevent the microcarriers from passing therethrough. Filter <NUM> can be comprised of a sheet of the same materials as discussed above with regard to filter <NUM>. Furthermore, filter <NUM> can be expandable and/or resilient, if desired. Filter <NUM> can be attached to or integrally formed with container <NUM>.

In embodiments in which body <NUM> is comprised of two or more panels, filter <NUM> can be attached to body <NUM> by placing filter <NUM> between the panels so that as the panels are welded together, filter <NUM> is concurrently welded therebetween. For example, if container <NUM> is a pillow style bag which is comprised of two overlying panels, filter <NUM> can be placed between the overlying panels. As the perimeter edges of the panels are welded together to form the bag, filter <NUM> is concurrently secured to or welded into the weld matrix so that filter <NUM> bisects the compartment of the pillow bag. This method is particularly useful where filter <NUM> is comprised of a perforated sheet of a polymeric material but can also be used with netting and other materials. In an alternative method, a perimeter edge of filter <NUM> can be secured on a face of a first panel by welding, adhesive, or the like. A second panel can then overlay the first panel and the second panel welded to the first panel either over top of or adjacent to filter <NUM>. In embodiments where container <NUM> is comprised of three or more panels, portions of filter <NUM> can be welded between different panels. Likewise, where container <NUM> comprises an extruded tube and opposing end panels, filter <NUM> can be welded or otherwise secured between the tube and one of the end panels or can be secured to one of the tube or the end panels and then the tube and end panel secured together.

Continuing with <FIG>, filter <NUM> has an inlet surface <NUM> and an opposing outlet surface <NUM> that extend from a first end <NUM> at top end wall <NUM> of container <NUM> to a second end <NUM> at bottom end wall <NUM> or side wall <NUM> of container <NUM>. Inlet chamber <NUM> is bounded by the interior surface <NUM> of a portion of container <NUM> and inlet surface <NUM> of filter <NUM>, and outlet chamber <NUM> is bounded by the interior surface <NUM> of the remaining portion of container <NUM> and outlet surface <NUM> of filter <NUM>. Inlet port <NUM> is positioned on top end wall <NUM> so as to fluidly communicate with inlet chamber <NUM> and outlet port <NUM> is positioned on bottom end wall <NUM> so as to fluidly communicate with outlet chamber <NUM>. As such, fluid passes through filter <NUM> as it moves between inlet and outlet ports <NUM> and <NUM>.

Similar to filter assembly <NUM>, filter assembly <NUM> also incorporates receptacle <NUM> into which container <NUM> is received. As such, similar to filter assembly <NUM>, filter assembly <NUM> can also be configured in different shapes, as discussed above and can include hanging tabs and hangers, as discussed above with respect to filter assembly <NUM>. In this embodiment, however, inlet port <NUM> would function as filter port <NUM> with regard to being modified or otherwise connected to receptacle <NUM> as discussed above with respect to filter port <NUM>.

Filter <NUM> is typically comprised of a sheet of flexible material but could be comprised of a sheet of rigid or semi-rigid material. As such, filter <NUM> can be substantially planar or have one or more curves between first and second ends <NUM> and <NUM>. Furthermore, filter <NUM> can be substantially taut or substantially loose. In the depicted embodiment, first end <NUM> of filter <NUM> is positioned at about the middle of top end wall <NUM> and second end <NUM> is positioned at bottom end wall <NUM> adjacent side wall <NUM>. For example, first end <NUM> of filter <NUM> can be positioned on top end wall <NUM> nearer side wall <NUM>, if desired. Also, first end <NUM> or second end <NUM> or both can be positioned on side wall <NUM> instead of top and bottom end walls <NUM> and <NUM>. Regardless of the positioning of first and second ends <NUM> and <NUM> of filter <NUM>, however, filter <NUM> is positioned such that inlet port <NUM> directly fluidly communicates with inlet chamber <NUM> and outlet port <NUM> directly fluidly communicates with outlet chamber <NUM>.

Similar to filter assembly <NUM>, filter assembly <NUM> can be positioned before use within first chamber <NUM> of receptacle <NUM>, and the top of container <NUM> can be attached to receptacle <NUM> using hanging tabs or other hanging elements. Also similar to filter assembly <NUM>, outlet tube <NUM> can be connected to outlet port <NUM> and extended through central opening <NUM> and out from support housing <NUM> through access port <NUM>, as shown in <FIG>.

During use, inlet tube <NUM> is coupled with bioreactor <NUM> (<FIG>) so that a mixture of cultured solution and associated microcarriers can be introduced into inlet chamber <NUM> therethrough. The cultured solution portion of the mixture passes through filter <NUM> and into outlet chamber <NUM>, where the fluid can collect or exit container <NUM> through outlet port <NUM> and outlet tube <NUM>. Filter <NUM> causes the microcarriers to be retained within inlet chamber <NUM> to be discarded or recycled for further used.

More specifically, the mixture passes through inlet port <NUM> and is received by inlet chamber <NUM> through fluid passageway <NUM>, as depicted in <FIG>. As shown in <FIG>, as the mixture is first received within inlet chamber <NUM>, as denoted by arrow <NUM>, inlet chamber <NUM> is completely or mostly devoid of microcarriers and the cultured fluid can pass through filter <NUM> along its entire length into outlet chamber <NUM>, as indicated by arrows <NUM>. The cultured fluid can then pass out of outlet chamber <NUM> through outlet port <NUM>, as denoted by arrow <NUM>.

As more mixture flows into inlet chamber <NUM>, the microcarriers <NUM> begin to accumulate at the bottom of inlet chamber <NUM> as the cultured fluid continues to pass through filter <NUM>, as shown by arrows <NUM> and <NUM> in <FIG>. As can be seen, because second end <NUM> of filter <NUM> extends to and is supported by top end wall <NUM> of container <NUM>, fluid can continue to flow through the upper portion of filter <NUM> not covered by microcarriers, as denoted by arrows <NUM>, even as more microcarriers may accumulate at the bottom portion of filter <NUM>. If an expandable material is used for filter <NUM>, the weight of the microcarriers can cause filter <NUM> to expand downward and outward, as depicted in <FIG>. This expansion increases the surface area of side surfaces <NUM> and <NUM> (<FIG>) of filter <NUM> which allows for more cultured solution to flow through the sides of filter <NUM> and more microcarriers to be retained.

<FIG> depicts another embodiment of a filter assembly <NUM>. Again, like elements between different embodiments are identified by like reference characters. Filter assembly <NUM> includes container <NUM> and a filter <NUM> coupled with an outlet port <NUM> so as to extend upward into compartment <NUM>. Turning to <FIG>, outlet port <NUM> is similar to outlet port <NUM> but has an additional stem <NUM> extending upward from flange <NUM> (i.e., in the opposite direction from flange <NUM> as stem <NUM>). Stem <NUM> is generally collinear with stem <NUM>, although this is not required.

Filter <NUM> includes a sidewall <NUM> having an inside surface <NUM> and an opposing outside surface <NUM> extending from an open first end <NUM> to a spaced apart closed second end <NUM>. Inside surface <NUM> of sidewall <NUM> bounds a fluid passageway <NUM> extending therethrough. The open first end <NUM> of filter <NUM> couples with stem <NUM> so that fluid passageways <NUM> and <NUM> fluidly couple with each other and combine to form fluid passageway <NUM>. Stem <NUM>, <NUM>, and filter <NUM> can be substantially collinear, although that is not required. Filter <NUM> can attach to stem <NUM> by adhesive, welding, threaded connection, press fit, crimping or other known connecting method. In addition, if desired, a channel <NUM> can be formed on the inside surface <NUM> at first end <NUM> of filter <NUM> to aid in attaching to stem <NUM>, as in the depicted embodiment.

A plurality of openings <NUM> extend through sidewall <NUM> of filter <NUM> that are large enough to allow the cultured solution to flow through, but small enough to prevent the microcarriers from flowing through. The openings <NUM> can encircle and extend all along filter <NUM> or any portion thereof. In one embodiment, filter <NUM> comprises a stem that is substantially rigid so as to prevent filter <NUM> from collapsing as microcarriers build up around it. For example, filter <NUM> can be comprised of plastic, metal, composite, glass or the like. Openings <NUM> can be formed as part of a molding process or can subsequently be drilled or otherwise formed. Other methods for forming openings <NUM> can also be used.

As shown in <FIG>, during assembly, a hole is formed in bottom end wall <NUM>. Outlet port <NUM> is seated within the hole so that filter <NUM> extends upward into compartment <NUM> and flange <NUM> rests against bottom end wall <NUM>. Similar to other outlet ports discussed herein, conventional welding or other sealing technique can then be used to seal flange <NUM> to bottom end wall <NUM>.

Similar to other embodiments discussed herein, filter <NUM> divides compartment <NUM> into two separate chambers - an inlet chamber <NUM> and an outlet chamber <NUM>. Fluid passageway <NUM> corresponds to outlet chamber <NUM>. Thus, outlet chamber <NUM> is fluidly coupled with fluid passageway <NUM> of outlet port <NUM>. Inlet chamber <NUM> is the portion of compartment <NUM> external to outlet chamber <NUM>. Fluid flows from inlet chamber <NUM> to outlet chamber <NUM> through filter <NUM>, as discussed below.

As noted above, when outlet port <NUM> is attached to container <NUM>, filter <NUM> extends upward into compartment <NUM>. Filter <NUM> can extend as far upward into compartment <NUM> as desired. In some embodiments, filter <NUM> has a length that allows it to contact and, if desired, attach to top end wall <NUM> of container <NUM>. Other lengths are also possible. Filter <NUM> can be attached to outlet port <NUM> by adhesive, threaded connection or other attachment method. Alternatively, filter <NUM> can be integrally formed with outlet port <NUM>.

Similar to the filter assemblies discussed above, filter assembly <NUM> can be positioned before use within first chamber <NUM> of receptacle <NUM>, and the top of container <NUM> can be attached to receptacle <NUM> using hanging tabs or other hanging elements. Also similar to the filter assemblies discussed above, outlet tube <NUM> can be connected to outlet port <NUM> and extended through central opening <NUM> and out from support housing <NUM> through access port <NUM>, as shown in <FIG>.

Inlet tube <NUM> is also attached to inlet port <NUM> and extends to bioreactor <NUM> (<FIG>). During use a mixture of cultured solution and associated microcarriers are introduced into inlet chamber <NUM> through inlet port <NUM>. The cultured solution passes through the openings <NUM> (<FIG>) in the sidewall <NUM> of filter <NUM> and into outlet chamber <NUM>. The fluid flows down through fluid passageway <NUM> of outlet port <NUM> where the fluid can exit container <NUM> through outlet tube <NUM>. The microcarriers, which cannot pass through filter <NUM>, collect at the bottom of container <NUM>.

More specifically, the mixture passes through inlet port <NUM> and is received by inlet chamber <NUM> through fluid passageway <NUM>, as depicted in <FIG>. As shown in <FIG>, as the mixture is first received within inlet chamber <NUM>, as denoted by arrow <NUM>, inlet chamber <NUM> is completely or mostly devoid of microcarriers and the cultured fluid can pass through filter <NUM> along its entire length into outlet chamber <NUM>, as indicated by arrows <NUM>. The cultured fluid can then pass out of outlet chamber <NUM> through outlet port <NUM>, as denoted by arrow <NUM>. As more mixture flows into inlet chamber <NUM>, the microcarriers <NUM> begin to accumulate at the bottom of inlet chamber <NUM> as the cultured fluid continues to pass through the filter <NUM>, as shown by arrows <NUM> and <NUM> in <FIG>. As can be seen, however, as long as filter <NUM> extends upward beyond the retained microcarriers <NUM>, fluid can continue to flow through the upper portion of filter <NUM>, as denoted by arrows <NUM> even as more microcarriers may accumulate at the bottom portion of filter <NUM>. That is, because filter <NUM> extends vertically within container <NUM>, at least a portion of filter <NUM> remains openly exposed to receive the cultured solution even when a lower portion of filter <NUM> may be covered by microcarriers.

After use, filter assembly <NUM> can be discarded with the microcarriers. Alternatively, container <NUM> can be opened and the microcarriers recycled.

<FIG> depicts another embodiment of a filter <NUM> that can be used in place of filter <NUM> in filter assembly <NUM>. Similar to filter <NUM>, filter <NUM> also attaches to outlet port <NUM>. However, instead of being substantially vertical, filter <NUM> is substantially horizontal. To accommodate filter <NUM>, outlet port <NUM> includes a stem <NUM> that extends from a proximal end <NUM> at flange <NUM> to a spaced apart distal end <NUM>. The distal end <NUM> of stem <NUM> flairs out radially so as to be wider than at the proximal end <NUM> and has an opening <NUM> at distal end <NUM>.

A filtering element <NUM> is positioned over the opening <NUM> at the distal end <NUM> of stem <NUM>. Filtering element <NUM> has an outer surface <NUM> and an opposing inner surface <NUM> and can be made of any of the filtering materials discussed above. Thus, filtering element <NUM> permits cultured solution which includes the detached cells to pass through filtering element <NUM> but prevents microcarriers from passing therethrough. Stem <NUM> has an interior surface <NUM> that together with the inner surface <NUM> of filtering element <NUM> bounds a compartment <NUM> that is directly coupled with fluid passageway <NUM> of outlet port <NUM>. To accommodate for the weight of the microcarriers that may accumulate on the filtering material, a framework <NUM> can be positioned within compartment <NUM> to bolster filtering element <NUM> and prevent filtering element <NUM> from collapsing. Framework <NUM> can be comprised of intermingled struts and walls or can be a thick material through which fluid can pass. Regardless of its composition, framework <NUM> is configured to allow the cultured fluid to flow therethrough to outlet port <NUM>. To aid in the flow of the fluid, interior surface <NUM> can be angled to guide the fluid to the fluid passageway <NUM>.

Claim 1:
A filter assembly (<NUM>, <NUM>) for separating microcarriers from a fluid medium and cells, the filter assembly comprising:
a container (<NUM>) comprising a flexible bag bounding a sterile compartment (<NUM>) adapted to hold a fluid;
an inlet port (<NUM>, <NUM>) through which fluid comprising microcarriers, fluid medium, and cells flows into the compartment (<NUM>);
an outlet port (<NUM>) through which fluid comprising fluid medium and cells flows out of the compartment; and
a filter (<NUM>, <NUM>) disposed within the compartment (<NUM>) and bounding an inlet chamber (<NUM>, <NUM>), the filter dividing the compartment into the inlet chamber (<NUM>, <NUM>) that is fluidly coupled with the inlet port and an outlet chamber (<NUM>) that is fluidly coupled with the outlet port, characterized in that the filter allowing the fluid medium and the cells to pass therethrough but preventing the microcarriers disposed in the fluid medium from passing therethrough, the filter comprising a filter inlet port (<NUM>) communicating with the inlet chamber (<NUM>, <NUM>) and a dip tube line (<NUM>) extending between the filter inlet port (<NUM>) and the inlet port (<NUM>, <NUM>),
wherein the filter (<NUM>, <NUM>) comprises:
a plurality of sheets (<NUM>, <NUM>), at least one of the sheets being comprised of a porous material, the plurality of sheets being bounded together at their peripheries to form the inlet chamber (<NUM>, <NUM>); and
the filter inlet port (<NUM>) through which fluid flows into the inlet chamber, the filter inlet port extending through at least one of the plurality of sheets, the filter inlet port being fluidly coupled with the inlet port (<NUM>, <NUM>).