A System and Method for Particle Filtration

A SYSTEM AND METHOD FOR PARTICLE FILTRATION

RELATED APPLICATIONS

This application is a divisional of Australian Application No. 2010336424, filed on 22 December 2010, and is related to International Patent Application No.

PCT/US20 10/06 1866, filed on 22 December 2010 and claiming priority from US Provisional Application No. 61/294,61 1, filed on 13 January 2010 and US Provisional Application No.

61/289,730 filed on 23 December 2009; each of which is incorporated herein by reference.

BACKGROUND

Methods for separating cells from biological samples are important to many clinical procedures and to scientific research methods. In cord blood banking, umbilical cord blood may be volume reduced using a cell separation process before entering cryopreservation to reduce the long term storage cost. In cellular therapy, certain cell types may be enriched before transfusing into a patient to increase engraftment. Current filtration technologies for cell separation often fail to preserve cell viability and typically have low yields. For example, cell separation techniques that rely on size exclusion subject fragile cells to shear stress causing cell damage or lysis. The accumulation of cellular debris accelerates device fouling and clogging. Often cells isolated using such methods are activated, altered, damaged, or killed. Microfluidic devices are limited by the volume of sample that they can process. Simply increasing flow rate through such devices is unsuccessful because as flow rate increases, the shear stress of cell moving through the device also increases. Thus, shear stress limits the volumetric throughput. It is thus desirable to provide a method and device for particle filtration that does not use size exclusion as the filtration mechanism. In particular, it is desirable to provide a method and device for cell filtration that does not easily clog, that has high volumetric throughput, that is physically compact, and that does not damage or activate the cells.

SUMMARY

As described below, the present disclosure features a device for particle filtration and methods of using the device for the enrichment of viable cells. In particular, the present disclosure features the use of such devices for isolation of blood cell types, volume reduction of umbilical cord bloods, and preparation of stromal vascular fractions.

Advantageously, the device may provide for the high throughput filtration of large volumes of sample while preserving cell viability and providing high yields. Some embodiments of the present disclosure may comprise devices suitable for automation and high throughput processing, and some embodiments of the present disclosure may comprise systems that enable processing clinical samples in closed systems. Further, the method for using the device may provide for high performance, high recovery, and in some cases high purity. In addition, the method for using the device as applied to clinical sample processing, e.g. cord blood volume reduction, bone marrow stem cell enrichment, peripheral blood stem [Text continues on page 2.J la cell processing, and stromal vascular fraction preparation, may provide for maintaining a high degree of post-separation cell viability, ease of use, safety, and cost efficiency.

In one embodiment, the disclosure provides a particle filtration device that provides for the high-throughput separation of viable cells. Because the particle filtration device provides for particle separation with minimal shear force at least about 50%, 75%, 85%, 95%, 98%, 99%, 99.5% or more of the separated cells are viable and suitable for research and medical use. In various embodiments, the filtration system features one or more containers suitable lor holding a sample and/or carrier fluid for delivery to one or more filter unit devices, and one or more additional containers suitable for holding retentate or filtrate flowing out of the device. In one embodiment, the containers are flexible bags suitable for holding liquids. In another embodiment, the containers are connected to the filter unit by flexible tubing suitable for carrying lluids. If desired, the tubing is connected to the container and/or filter unit housing by an adapter.

Aspects and embodiments of the disclosure are directed to a system for particle filtration containing a cartridge containing a housing and a plurality (for example, about 5, 10, 15, 20, 25, 30, 35,40, 50, 75, 100, 200, 250, 500, 750, 1,000, 2,000, or 5,000) of filtration units, where the housing contains a feed sample inlet, a retentate outlet, and a filtrate outlet; and each filtration unit contains a retentate chamber having proximal and distal ends, a filtrate chamber, and a row of pillars positioned between the retentate chamber and the filtrate chamber, the pillars defining a plurality of pores permitting fluid communication between the retentate chamber and the filtrate chamber, where the width of the retentate chamber decreases from the proximal end to the distal end, the width of the filtrate chamber increases from the proximal end to the distal end, and the filtration unit is configured such that the effective pore size of the pores is smaller than, for example, about 30%, 50%, 60%, 70%, 80%, 90%, 95%, or 98% of the physical pore size of the pores; the feed sample inlet is in fluid connection with the proximal end of the retentate chamber present in each filtration unit; the filtrate outlet is in fluid connection with the filtrate chamber present in each filtration unit; and the retentate outlet is in fluid connection with the distal end of the retentate chamber present in each of the plurality of filtration units.

In another aspect, the disclosure provides a system for particle filtration containing a cartridge comprising a housing and a plurality of filtration units, where the housing contains a feed sample inlet, a retentate outlet, and a filtrate outlet; and each filtration unit contains a retentate chamber having proximal and distal ends, a filtrate chamber containing at least one distal end, and a filter containing a plurality of pores positioned between the retentate chamber and the filtrate chamber, the pores permitting fluid communication between the retentate chamber and the filtrate chamber, where the filtrate chamber, the filter and the leieniate chamber are configured such that the effective pore size of the pores is smaller than the physical pore size of the pores; the feed sample inlet is in fluid connection with the proximal end of the retentate chamber present in each filtration unit; the filtrate outlet is in fluid connection with the filtrate chamber present in each filtration unit; and the retentate outlet is in fluid connection with the distal end of the retentate chamber present in each of the plurality of filtration units.

In another aspect, the disclosure provides a system for particle filtration containing a cartridge containing a housing and a plurality of filtration units, where the housing contains a feed sample inlet, a retentate outlet, and a filtrate outlet; and each filtration unit contains a first flow chamber, a second flow chamber, and a filter containing about 3, 5, 6, 7, 8, 9, 10, 15, 20, 25, 30, 40, 50, 100, 200, 250, 300, 500, 1,000, 2,000, 5,000 or more pores having a physical pore size between about 100 nm and about 3 mm (for example, about 100 nm, 200 nm, 300 nm, 400 nm, 500 nm, 750 nm, 1 μm, 2 μm, 3 μm, 5 μrn, 7.5 μrn, 10 μm, 20 μru, μrn, 50 μm, 75 μm, 100 μm, 200 μm, 300 μm, 500 μm, 1 mm, 2 mm, or 3 ram) where the filter is disposed between the first flow chamber and the second flow chamber; and the first flow chamber and second flow chamber are configured such that the retentate particles are retained by die filter without physical restriction; the feed sample inlet is in fluid connection with the proximal end of the first flow chamber present in each filtration unit; the filtrate outlet is in fluid connection with the distal end of the second chamber present in each filtration unit; and the retentate outlet is in fluid connection with the distal end of the first flow chamber present in each of the plurality of filtration units.

In another aspect, the disclosure provides a system for particle filtration containing a cartridge containing a housing and a plurality of filtration units, where the housing contains a feed sample inlet, a retentate outlet, and a filtrate outlet; and each filtration unit contains a first flow chamber having proximal and distal ends, a second flow chamber, and a filter disposed between the first flow chamber and the second flow chamber containing pores having a physical pore size between about 10 nm and 10 mm, where the fist flow chamber and second flow chamber are configured such that the retention size of the filter is smaller than the physical pore size; the feed sample inlet is in fluid connection with the proximal end of the first flow chamber present in each filtration unit; the filtrate outlet is in fluid connection with the distal end of the second flow chamber present in each filtration unit; and the retentate outlet is in fluid connection with the distal end of the first flow chamber present in each of the plurality of filtration units.

In another aspect, the disclosure provides a system for particle filtration containing a cartridge containing a housing and a plurality of filtration units, where the housing contains a feed sample inlet, a retentate outlet, a filtrate outlet, and optionally a carrier fluid inlet. Each filtration unit may include a first input port, a first output port, a second output port, and optionally a second input port in fluid connection with the carrier fluid inlet. Each filtration unit may have a design efficiency index of greater than about 0.3 nun'2. The feed sample inlet may be in fluid connection with the first input port present in each filtration unit. The filtrate outlet may be in fluid communication with the first output port present in each filtration unit. The retentate outlet may be in fluid connection with the second output port present in each of the plurality of filtration units.

In another aspect, the disclosure provides a tube filter system containing a centrifuge tube, a tube insert, and a cap, where the tube insert contains at least one filtration unit according to any of the previous aspects, a feed sample reservoir and optionally a carrier fluid reservoir, each of which is in fluid connection with the first flow chamber or the proximal end of the retentate chamber, and an output reservoir in fluid communication with the distal end of the retentate chamber or the second flow chamber, where the output reservoir is adapted to receive the retentate or filtrate from the filtration unit.

In another aspect, the disclosure provides a plate filter system containing one or more of a sample well and optionally a earner fluid well in fluid connection with a filtration unit according to any previous aspect or any other aspect of the disclosure delineated herein; and a filtrate well and a retentate well in fluid connection with the filtration unit, where the filtrate well and a retentate well are configured to receive filtrate and retentate from the filtration unit.

In another aspect, the disclosure provides a plate filter system containing one or more of a sample well and optionally a carrier fluid well in fluid connection with a filtration unit according to any previous aspect or any other aspect of the disclosure delineated herein; and a filtrate well and a retentate well, where the filtrate well and a retentate well are configured to receive filtrate and retentate front the filtration unit. In one embodiment, the filtrate well or the retentate well is not on the same plate as the sample well.

In various embodiments of any of the above aspects or any other aspect of the disclosure delineated herein the feed sample inlet has a proximal end connected to an adaptor via a tubing line, the retentate outlet is connected to a retentate collection bag via a tubing line, and the filtrate outlet is connected to a filtrate collection bag via a tubing line. In other embodiments of the above aspects, the feed sample inlet is connected to a sample collection bag having proximal and distal ends, where the proximal end contains a membrane adapted to receive a needle and the distal end contains a port where an adaptor can be attached. In other embodiments of the above aspects, the feed sample inlet has a proximal end connected to a sample collection bag via a tubing line, the retentate outlet is connected to a retentate collection bag via a tubing line, and the filtrate outlet is connected to a filtrate collection bag via a tubing line. In still other embodiments of the above aspects, the sample collection bag contains a needle for drawing sample into the sample collection bag.

Compositions and articles defined by the disclosure were isolated or otherwise manufactured in connection with the examples provided below. Other features and advantages of the disclosure will be apparent from the detailed description, and from the