WO2025242707A1

WO2025242707A1 - Device for filtering fluid samples and method for detecting concentration of particles in the fluid samples by filtration

Info

Publication number: WO2025242707A1
Application number: PCT/EP2025/063932
Authority: WO
Inventors: Jesús ALONSO EXTREMO; Xabier MENDIBIL BLASCO; Jon ALBERDI TELLERIA; Iñigo ARIZAGA GURRUTXAGA; Juan Manuel FALCÓN PÉREZ; Donatello CASTELLANA; Félix Miguel ROYO LÓPEZ
Original assignee: Fundacion Tekniker; Centro de Investigacion Cooperativa en Biociencias; Centro de Investigacion Biomedica en Red CIBER
Current assignee: Fundacion Tekniker; Centro de Investigacion Cooperativa en Biociencias; Centro de Investigacion Biomedica en Red CIBER
Priority date: 2024-05-21
Filing date: 2025-05-21
Publication date: 2025-11-27
Anticipated expiration: 2026-11-21

Abstract

The present invention relates to a device for filtering fluid samples and a method for detecting concentration of particles, and more particularly to a filtering device capable of filtering fluid samples at different filtering levels and a method for detecting the concentration of particles trapped in the filters of the device for each fluid sample.

Description

DEVICE FOR FILTERING FLUID SAMPLES AND METHOD FOR DETECTING CONCENTRATION OF PARTICLES IN THE FLUID SAMPLES BY FILTRATION

DESCRIPTION

TECHNICAL FIELD OF THE INVENTION

BACKGROUND OF THE INVENTION

Multi-well filtration assemblies are known in the art and are used for the assay of biological liquid specimens. Conventional filtration assemblies typically comprise a filtration plate having multiple filtration wells for receiving a liquid specimen, and a collection tray having a plurality of collection wells for collecting filtrate.

The filtration plate and the collection tray are disposed in a stacked relationship such that individual collection wells are associated each with a single filtration well. A conventional multi-well filtration plate has 96 wells for performing multiple assays simultaneously. Each well typically contains a separation media, for example a filter member, for separating a biological component from the liquid that is introduced into the filtration plate, and allowing a liquid portion of the biological liquid to filter into the collection tray.

These multi-well filtration assemblies only allow for a single filtration and if the biological liquid specimens are to be filtered more than once, they must be deposited in a new multi-well filtration assembly, and so each time the sample has to be filtered.

Therefore, to be able to carry out multiple filtrations for the same biological liquid specimen the use of many multi-well filtration assemblies is required. At the same time, having to extract the sample from a first multi-well filtration assembly and take it to another filtration assembly and so on as many times as necessary exposes the sample to contamination.

The present invention provides a device for filtering several times a plurality of samples at a time and a method for detecting the concentration of particles in fluid samples by filtration.

SUMMARY OF THE INVENTION

The present invention provides a device for filtering according to claim 1 , a system according to claim 13 and a method for detecting the concentration of particles in fluid samples according to claim 17. In dependent claims, preferred embodiments of the invention are defined.

In a first inventive aspect, the present invention provides a device for filtering fluid samples, the device comprising: a plurality of inlet wells for fluid sample deposition; a plurality of outlet wells for filtered fluid sample collection; a plurality of channels, each channel connecting one inlet well with one outlet well; and a plurality of filters interposed in each channel and separated from each other along the channels; wherein: each filter is configured to retain particles of the fluid samples according to a predefined criterion, wherein the predefined criterion is different for each filter, and the plurality of filters is removable from the device.

The present device is a filtering device suitable for filtering fluid samples that may be biological or non-biological, supplied to the device. The device is configured for allowing to filter different fluid samples at the same time and in the same filtering device.

The present device comprises a plurality of inlet wells and outlet wells wherein each inlet well is in fluid communication with a respective outlet well through a channel, so that there is also a plurality of channels in the device. The device is configured so that the inlet wells are arranged over the outlet wells so that the fluid samples flows from the inlet wells to the outlet wells in an operative mode of the filtering device. The direction in which the fluid samples flow from the inlet wells to the outlet wells when the device is in an operative mode will be defined for this document as sample flow direction.

In addition, the device comprises filters which are interposed in each channel and separated from each other along the channel, so that the device is configured with different filtering levels. Specifically, each filter (according to a filtering level) is configured to retain particles of the fluid samples according to a predefined criterion, such as filtering by particle size. This predefined criterion of the filters is different for each filter, that is, the criterion varies along the sample flow direction of the fluid samples in the operative mode of the device.

Furthermore, the filters are removable from the device. This allows the filters at each filtering level to be removed from the device for further analysis. In an embodiment, the filters are connected one to another so that they are removable from the device at the same time. In another embodiment, each filter is removable from the device independently of the others.

Advantageously, the present device allows many fluid samples to be processed simultaneously for filtration with no cross-contamination between them as the device comprises separate and independent inlets, outlets and connecting channels between such inlets and outlets, for each fluid sample. Moreover, the device allows recovering each fluid sample individually after the filtration. In addition, the device provides different filtering levels for filtering a large number of fluid samples quickly. Therefore, the present device has the ability to filter and collect multiple samples at the same time reducing time and cost and minimizing the confusion between samples by human error.

In an embodiment, the fluid sample is a biological or non-biological sample containing particles above 100 nm. In an embodiment, the fluid sample comprises proteins, lipids, nucleic acids, metabolites or any combination thereof.

In an embodiment, the predefined criterion is a predefined particle size, each filter comprises a plurality of pores having a predefined pore size, and the predefined pore size of the filters decreases from the inlet wells to the outlet wells. Each filter comprises a plurality of pores with predefined pore size and the predefined criterion for filtering by each filter is a predefined particle size.

According to this embodiment, the filters are configured for filtering by particle size so that each filter is provided with a plurality of pores the size of which decreases between filters along the sample flow direction of the fluid sample in the operative mode of the device. That is, the pore size of the filters is different in each filtering level. Thus, the filters retain particles of the fluid samples when the fluid samples pass through the filters. For each filtering level a certain amount of particles shall be retained for each fluid sample, i.e. for each channel connecting a respective inlet well with a respective outlet well.

In an embodiment, the filters are functionalized in such a way that when the fluid sample comes into contact with the filter, the filter reacts to trap particles of the fluid sample, not because of their size but because of their composition. In this case, the predefined criterion of the filters is the ability of a particle to react with the functionalized filter.

In an embodiment, the filters are used for protein immunodetection technology; or the filters are used for nucleic acid amplification; or the filter are used for fluorescence detection; or the filters are used for luminescence detection.

In an embodiment, the inlet wells comprise a conical frustum section, wherein, for each inlet well, the smallest diameter base of the conical frustum section connects with a first end of the channel. The conical frustum section of the inlet wells is provided at outlet of the inlet wells. Specifically, the smallest diameter base of the conical frustum section connects with the first end of the channel. Advantageously, this conical frustum section of the inlet wells endows the device with the ability to concentrate the fluid sample in a specific area of the filters.

In an embodiment, the device comprises a plurality of support plates, the support plates being stacked, and wherein each support plate supports one filter and is removable from the device. That is, each filter is supported on a support plate for a filtering level in the device. The support plates can be independent of each other or linked to each other; in either case the support plates are removable from the device. The removal of these support plates allows the filters to be taken out of the device and taken to another location for further processing.

In an embodiment, each support plate comprises a plurality of through holes, wherein each through hole defines a section of a channel, and wherein the through holes of one support plate are aligned with the through holes of the rest of support plates. Thus, when a plurality of support plates are stacked, the through holes of the plurality of support plates are aligned and a channel is defined by each alignment of through holes. Since each support plate comprises a plurality of through holes, a plurality of channels is formed when the support plates are stacked.

In an embodiment, the sealing gasket comprises a plate-shaped configuration with a plurality of holes, and the regions where the filter is interposed in the channel coincide with the holes.

In an embodiment, each support plate comprises around the through holes a recess where the sealing gasket is placed.

In an embodiment, the device comprises: a first support supporting the inlet wells, and a second support supporting the outlet wells; wherein both first and second supports are fixed to each other by fixing means.

In an embodiment, the device comprises for each filter a sealing gasket arranged between the support plate and the filter except at least in the regions where the filter is interposed in the channels. Advantageously, the sealing gasket seals the joint between contiguous support plates and/or between a support plate and a supporting element, such as the first support, so that leakage of the fluid samples out of the channel and the device is prevented or at least minimized.

In an embodiment, the device comprises a sealing gasket arranged between the second support and the support plate closest to the second support. Advantageously, this sealing gasket seals the joint between the support plate and the second support so that a leakage of fluid samples is prevented or at least minimized.

In an embodiment, the plurality of filters comprises at least three filters. That is, the device comprises three or more filters arranged stacked and separated from each other, each filter defining a filtering level in the device.

In an embodiment, each filter comprises a plurality of filtering membranes.

In a second inventive aspect, the invention provides a system comprising a device according to the first inventive aspect and fluid driving means. The fluid driving means are in charge of driving fluid samples through the device from the inlet wells to the outlet wells, so that the fluid samples pass through all the filters and arrive to the outlet wells.

Advantageously, the present system allows the fluid samples to pass through the different filters in the sample flow direction with no cross-contamination and no filter breakage.

In an embodiment, the fluid driving means is pressurized air supply means. Specifically, the pressurized air supply means are based on the use of pressurized air as the driving element of the fluid sample through the device.

In an embodiment, the system comprises a cover configured to be placed covering the device above the inlet wells, wherein the cover comprises a plurality of ports configured to be connected to the pressurized air supply means to supply pressurized air to the inlet wells of the device.

The operation of the pressurized air supply means makes the fluid samples flow through the device from the inlet wells to the outlet wells. Advantageously, the plurality of ports provides a homogeneous pressurized air distribution through the device.

In another embodiment, the fluid driving means is centrifugal force means. This centrifugal force means centrifuges the device to make the fluid samples flow from the inlet wells to the outlet wells of the device. Advantageously, the driving forces of the centrifugal force means homogeneously push the sample fluid through the device. ln a third inventive aspect, the invention provides a method for detecting the concentration of particles in fluid samples by filtration, the method comprising:

(a) providing a system according to the second inventive aspect;

(b) inserting a fluid sample in each inlet well of the device;

(c) driving the fluid samples through the device by fluid driving means so that fluid samples flow through the channels, being filtered by the filters until the fluid samples reach the outlet wells of the device;

(d) removing the filters from the device; and

(e) detecting the concentration of particles that have been trapped in each filter for each fluid sample.

The present method allows detecting the concentration of particles of a plurality of fluid samples by filtration of such fluid samples at the same time and in different filtering levels. That is, each fluid sample is filtered several times by different filters. Then, the filters are removed from the device in order to process the particles trapped in the filters for each fluid sample.

Advantageously, this method allows filtering a large number of fluid samples at the same time and processing outside the filtering device the particles trapped in each filtration carried out in the device.

DESCRIPTION OF THE DRAWINGS

These and other characteristics and advantages of the invention will become clearly understood in view of the detailed description of the invention which becomes apparent from a preferred embodiment of the invention, given just as an example and not being limited thereto, with reference to the drawings.

Figure 1 This figure shows a schematic cross-section view of a device according to an embodiment of the present invention.

Figure 2 This figure shows an enlarged portion of figure 1.

Figure 3 This figure shows an enlarged portion of figure 2.

Figure 4 This figure shows an enlarged portion of figure 2.

Figure 5 This figure shows a schematic perspective view of a system according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Figure 1 shows a cross-section view of a filtering device (1) according to an embodiment wherein the device (1) is adapted for filtering fluid samples. The device (1) comprises a plurality of inlet wells (2) for fluid sample deposition and a plurality of outlet wells (3) for filtered fluid sample collection. There are the same number of inlet wells (2) as outlet wells (3). In addition, the device comprises a channel (4) connecting one inlet well (2) with one outer well (3). In this sense, each inlet well (2) is in fluid communication with the corresponding outlet well (3) through a channel (4). In particular, figure 1 shows twelve inlet wells (2), twelve outlet wells (3) and twelve channels (4).

The device (1) of figure 1 further comprises a first support (1.1) housing the inlet wells

(2) and a second support (1 .2) supporting the outlet wells (3). The first (1.1) and second (1.2) support are both fixed by fixing means (10), such as bolting. In addition, the device (1) shown in this figure 1 comprises a cover (8) covering the device (1) above the inlet wells (2).

Figure 2 shows an enlarged portion of the filtering device (1) of the embodiment shown in figure 1. Specifically, figure 2 shows three inlet wells (2), three outlet wells (3) and three channels (4), close to one end of the device (1). The device (1) further comprises three filters (5A, 5B, 5C) interposed in the channels (4) and separated from each other along the channel (4), i.e. according to the fluid sample flow direction (s). The fact that the filters (5A, 5B, 5C) are interposed in the channels (4) implies that the channel (4) is divided in channel sections. Figure 3, which shows a single inlet well (2) and outlet well

(3) of the embodiment of figure 1 or 2, shows in detail the arrangement of these three filters (5A, 5B, 5C) interposed in the channel (4).

In this embodiment, each filter (5A, 5B, 5C) comprises a plurality of pores and is configured to retain particles of the fluid sample of a predefined size. Additionally, the retained particle size decreases between filters (5A, 5B, 5C) along the sample flow direction (s) from the inlet wells (2) to the outlet wells (3). That is, from the inlet wells (2) to the outlet wells (3) there are three filtering levels, namely a first filter (5A) with a first pore size, a second filter (5B) with a second pore size smaller than the first pore size, and a third filter (5C) with a third pore size smaller than the second pore size. In this embodiment, the predefined criterion according to which particles are retained in the filters (5A, 5B, 5C) is particle size.

As it can be observed further in detail in figure 3, each inlet well (2) comprises an inlet

(2.2) through which the fluid sample is deposited and a conical frustum section (2.1) opposite to the inlet (2.2) of the inlet well (2). The smallest diameter base of this conical frustum section (2.1) connects with a first end (4.1) of the channel (4). Moreover, each outlet well (3) comprises a conical frustum section (3.1) at the base of the outlet well (3) on which the fluid sample is deposited after filtration.

In an embodiment, the filtering device (1) comprises 96 inlet wells (2) and the respective outlet wells (3), so that the filtering device (1) is adapted for filtering a total of 96 fluid samples at the same time.

In an embodiment, from the inlet well (2) to the outlet well (3) there is a first filter (5A) with a pore size of 0,45 pm, a second filter (5B) with a pore size of 0,22 pm and a third filter (5C) with a pore size of 0,1 pm.

Figures 2 and 3 also show that in this embodiment the device (1) comprises a support plate (6A, 6B, 6C) for each filter (5A, 5B, 5C). These support plates (6A, 6B, 6C) are stacked, separated by the filter and supporting the filters (5A, 5B, 5C). These support plates (6A, 6B, 6C) with the filters (5A, 5B, 5C) are removable from the device (1) independently of each other. Each support plate (6A, 6B, 6C) comprises a through hole

(6.2) defining a section of the channels (4). Also, the through holes (6.2) of one support plate (6A, 6B, 6C) are aligned with the through holes (6.2) of the rest of support plates (6A, 6B, 6C).

Figures 2 and 3 further show a sealing gasket (7A, 7B, 7C) arranged between each support plate (6A, 6B, 6C) and the corresponding filter (5A, 5B, 5C), except at least in the sections where the filter (5A, 5B, 5C) is interposed in the channels (4). These sealing gaskets (7A, 7B, 7C) have a plate-shaped configuration with holes (7.1) that coincide with the regions where the filter (5A, 5B, 5C) is interposed in the channels (4). In addition, the support plates (6A, 6B, 6C) comprise a recess (6.1) (see figure 3) around the through holes (6.2), and this recess (6.1) is where the sealing gasket (7A, 7B, 7C) is received. Furthermore, there is another sealing gasket (7D) arranged between the support plate (6A, 6B, 6C) closest to the second support (1.2) and this second support (1.2).

Figure 4 shows an enlarged portion of figure 2. The provision of the three filters (5A, 5B, 5C) is visible in this figure, namely a first filter (5A) configured with a first pore size, a second filter (5B) configured with a second pore size and a third filter (5C) configured with a third pore size. In addition, this figure 4 shows a support plate (6A, 6B, 6C) for each filter (5A, 5B, 5C), wherein each support plate (6A, 6B, 6C) comprises through holes (6.2). Specifically, the through holes (6.2) of each support plate are aligned with the through holes (6.2) of the rest of support plates.

Moreover, figure 4 shows in detail how each through hole (6.2) of the support plates (6A, 6B, 6C) defines a section of a channel (4). Specifically, when the support plates (6A, 6B, 6C) are stacked as shown in this figure, the through holes (6.2) of the support plates (6A, 6B, 6C) are aligned and each channel (4) is defined by each alignment of through holes (6.2). Thus, each channel (4) is formed by three channel sections, a first channel section (4A) defined by a first support plate (6A), a second channel section (4B) defined by a second support plate (6B) and a third channel section (4C) defined by a third support plate (6C).

In an embodiment, each filter (5A, 5B, 5C) comprises a plurality of filtering membranes.

In an embodiment, the filters (5A, 5B, 5C) are intended to immunodetection or PCR analyses.

In an embodiment, the fluid samples used for the present device (1) and method are biological fluids from the human or animal body, such as urine, blood, etc

Figure 5 shows a system according to an embodiment of the invention, this system comprising the device (1) already described above for figures 1-4 and fluid driving means for driving the fluid samples through the device (1). Specifically, the system shown in figure 5 comprises pressurized air supplying means (not shown) as fluid driving means. In addition, figure 5 shows a cover (8) covering the device (1) above the inlet wells (2). This cover (8) comprises a plurality of ports (9) for supplying pressurized air into the inlet wells (2) by the actuation of the pressurized air supply means. Specifically, the system of figure 5 shows six ports (9) to distribute the pressurized air homogeneously to the inlet wells (2) of the device (1).

In another embodiment not shown, the fluid driving means is centrifugal force means.

Furthermore, the present invention provides a method for detecting the concentration of particles in fluid samples by filtration. According to an embodiment, this method comprises the following steps:

(a) providing the system shown in figure 5;

(b) inserting a fluid sample in each inlet well (2) of the device (1);

(c) supplying pressurized air into the device (1) through the plurality of ports (9) by the pressurized air supply means, so that the fluid samples flow from the inlet wells (2) to the outlet wells (3) passing through the channel (4) and being filtered by each filter (5A, 5B, 5C);

(d) removing from the device (1) the support plates (6A, 6B, &C) supporting the corresponding filter (5A, 5B, 5C); and

(e) detecting the concentration of particles that have been trapped in each filter (5A, 5B, 5C) for each fluid sample.

Claims

1.- A device (1) for filtering fluid samples, the device (1) comprising: a plurality of inlet wells (2) for fluid sample deposition; a plurality of outlet wells (3) for filtered fluid sample collection; a plurality of channels (4), each channel (4) connecting one inlet well (2) with one outlet well (3); and a plurality of filters (5A, 5B, 5C) interposed in each channel (4) and separated from each other along the channels (4); wherein: each filter (5A, 5B, 5C) is configured to retain particles of the fluid sample according to a predefined criterion, wherein the predefined criterion is different for each filter (5A, 5B, 5C), and the plurality of filters (5A, 5B, 5C) is removable from the device (1).

2.- The device according to the previous claim, wherein the predefined criterion is a predefined particle size, wherein each filter (5A, 5B, 5C) comprises a plurality of pores having a predefined pore size, and wherein the predefined pore size of the filters decreases from the inlet wells (2) to the outlet wells (3).

3.- The device according to any one of the previous claims, wherein the inlet wells (2) comprise a conical frustum section (2.1), wherein, for each inlet well (2), the smallest diameter base of the conical frustum section (2.1) connects with a first end (4.1) of the channel (4).

4.- The device according to any one of the previous claims, further comprising a plurality of support plates (6A, 6B, 6C), the support plates (6A, 6B, 6C) being stacked, and wherein each support plate (6A, 6B, 6C) supports one filter (5A, 5B, 5C) and is removable from the device (1).

5.- The device according to the previous claim, wherein each support plate (6A, 6B, 6C) comprises a plurality of through holes (6.2), wherein each through hole (6.2) defines a section of a channel (4), and wherein the through holes (6.2) of one support plate (6A, 6B, 6C) are aligned with the through holes (6.2) of the rest of support plates (6A, 6B, 6C).

6.- The device (1) according to any one of claims 4 to 5, further comprising for each filter (5A, 5B, 5C) a sealing gasket (7A, 7B, 7C) arranged between the support plate (6A, 6B, 6C) and the filter (5A, 5B, 5C) except at least in the regions where the filter (5A, 5B, 5C) is interposed in the channels (4).

7.- The device (1) according to the previous claim, wherein the sealing gasket (7A, 7B, 7C) comprises a plate-shaped configuration with a plurality of holes (7.1), and wherein the regions where the filter (5A, 5B, 5C) is interposed in the channel (4) coincide with the holes (7.1).

8.- The device (1) according to claim 5 and any one of claims 6 to 7, wherein each support plate (6A, 6B, 6C) comprises around the through holes (6.2) a recess (6.1) where the sealing gasket (7A, 7B, 7C) is placed.

9.- The device (1) according to any one of the previous claims, further comprising: a first support (1.1) supporting the inlet wells (2), and a second support (1.2) supporting the outlet wells (3); wherein both first (1.1) and second (1 .2) supports are fixed to each other by fixing means (10).

10.- The device (1) according to the previous claim, further comprising a sealing gasket (7D) arranged between the second support (1.2) and the support plate (6A, 6B, 6C) closest to the second support (1 .2).

11.- The device (1) according to any one of the previous claims, wherein the plurality of filters (5A, 5B, 5C) comprises at least three filters.

12.- The device (1) according to any one of the previous claims, wherein each filter (5A, 5B, 5C) comprises a plurality of filtering membranes.

13.- A system comprising a device (1) according to any one of the previous claims and fluid driving means.

14.- The system according to the previous claim, wherein the fluid driving means is pressurized air supply means.

15.- The system according to the previous claim, further comprising a cover (8) configured to be placed covering the device (1) above the inlet wells (2), wherein the cover (8) comprises a plurality of ports (9) configured to be connected to the pressurized air supply means to supply pressurized air to the inlet wells (2) of the device (1).

16.- The system according to claim 13, wherein the fluid driving means is centrifugal force means.

17.- A method for detecting the concentration of particles in fluid samples by filtration, the method comprising:

(a) providing a system according to any one of claims 13 to 16;

(b) inserting a fluid sample in each inlet well (2) of the device (1);

(c) driving the fluid samples through the device (1) by fluid driving means so that fluid samples flow through the channels (4), being filtered by the filters (5A, 5B, 5C) until the fluid samples reach the outlet wells (3) of the device (1);

(d) removing the filters (5A, 5B, 5C) from the device (1); and