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WO-2026093512-A1 - MULTI-LAYERED MEMBRANE

WO2026093512A1WO 2026093512 A1WO2026093512 A1WO 2026093512A1WO-2026093512-A1

Abstract

The present invention relates to a multi-layered membrane comprising at least one layer of a porous pre-filter material, a track-etched membrane and a layer comprising a porous flow distribution material, a process for preparation of such a multi-layered membrane as well as the use of such membranes for the separation of cells or other larger items from fluid, especially from body fluids and more specifically for the separation of blood into blood cells and serum or plasma.

Inventors

  • CATALDO, WILLIAM
  • RICKEN, Gerda
  • SARNA-MCCARTHY, Marissa
  • SHEEDY, Shane
  • TOSONI, LUCA

Assignees

  • OXYPHEN GMBH

Dates

Publication Date
20260507
Application Date
20251031
Priority Date
20241031

Claims (20)

  1. 1 . A multi-layered membrane comprising: (a) a top layer comprising at least one layer of porous pre-filter material having pores having a pore size equal to or larger than the pore size of the track-etched membrane (b); (b) a middle layer comprising a track-etched membrane; and (c) a bottom layer comprising a porous flow distribution material, wherein the multi-layered membrane includes a hydrophilic coating on at least the track-etched membrane.
  2. 2. The multi-layered membrane according to claim 1 , which consists of layers (a), (b) and (c).
  3. 3. The multi-layered membrane according to claim 1 or 2, wherein layer (a) comprises two layers of porous pre-filter material having pores having a pore size equal to or larger than the pore size of the track- etched membrane (b) which can rest directly on top of each other, or which can be separated by an air gap.
  4. 4. The multi-layered membrane according to claim 1 to 3, wherein a hydrophilic coating is additionally provided on at least one side of the top layer (a) and/or bottom layer (c).
  5. 5. The multi-layered membrane according to any of claims 1 to 4, wherein the porous pre-filter material (a) and/or porous flow distribution layer material (c) is a hydrophilic, natural, synthetic, woven or non-woven polymeric fiber material or other porous media.
  6. 6. The multi-layered membrane according to any of claims 1 to 5, wherein the porous pre-filter material (a) and/or porous flow distribution material (c) is a non-woven material comprising bi-component polymeric fibers. 222647PEP/HCath 27
  7. 7. The multi-layered membrane according to any of claims 1 to 6, wherein the bi-component polymeric fibers are selected from the group comprising coPET/PET (co-extruded Polyethylene Terephthalate I Polyethylene Terephthalate), PET/PP (Polyethylene Terephthalate I Polypropylene), PE/PP (Polyethylene I Polypropylene), PET/PBT (Polyethylene Terephthalate I Polybutylene Terephthalate), and PET/Nylon (Polyethylene Terephthalate I Nylon).
  8. 8. The multi-layered membrane according to any of claims 1 to 7, wherein the pre-filter material (a) and the flow distribution material (c) are the same or different, wherein the materials optionally differ in pore size, pore density, material thickness, or hydrophilic coating.
  9. 9. The multi-layered membrane according to any of claims 1 to 8, wherein the pre-filter material (a) and the flow distribution material (c) are a PET non-woven porous material.
  10. 10. The multi-layered membrane according to any of claims 1 to 9, wherein the material of the track-etched membrane is selected from polyethylene terephthalate (PET), polycarbonate (PC), polyimide (PI), polyvinylidene fluoride (PVDF), polyether ether ketone (PEEK), ethylene tetrafluoro ethylene (ETFE) and other polymers having similar properties, preferably PET or PC.
  11. 11 . The multi-layered membrane according to any of claims 1 to 10, wherein the pore size of the track-etched membrane is 0.1 to 5 pm, preferably 0.3 to 2.5 pm, more preferably 0.3 to 1 .75 pm, and wherein the pore density is 10,000 to 1 ,000,000,000 pores per cm 2 .
  12. 12. The multi-layered membrane according to any of claims 1 to 11 , wherein the thickness of the track-etched membrane is 1 to 100 pm, preferably 2 to 50 pm and more preferably 5 to 25 pm. 222647PEP/HCath 28
  13. 13. The multi-layered membrane according to any of claims 1 to 12, wherein the overall thickness of the multi-layered membrane is between 200 pm to 1000 pm, wherein the top layer (a) is preferably from 100 pm to 800 pm, more preferably from 200 pm to 600 pm the middle layer (b) is preferably from 1 pm to 100 pm, more preferably from 25 pm to 75 pm and the bottom layer (c) is preferably from 100 pm to 800 pm, more preferably from 200 pm to 600 pm.
  14. 14. The multi-layered membrane according to any of claims 1 to 13, wherein the pore size of porous pre-filter material is between 5 and 1000 pm, preferably between 10 and 500 pm and more preferably between 20 and 100 pm.
  15. 15. The multi-layered membrane according to any of claims 1 to 14, wherein all layers are joined, preferably by lamination.
  16. 16. The multi-layered membrane according to any of claims 1 to 15, wherein the hydrophilic coating comprises polyvinyl pyrrolidone (PVP), a sulfonated coating, or a coating containing alcoholic and carboxylic groups.
  17. 17. The multi-layered membrane according to any of claims 1 to 16, wherein the top layer (a) diffuses the whole blood sample and retains red and white blood cells, the middle layer (b) separates the sample by size, and the bottom layer (c) holds and/or distributes the obtained plasma, optionally transferring the plasma to a detection device, e.g., a microfluidic device or lateral flow detection device.
  18. 18. Process for the preparation of a multi-layered membrane according to any of claims 1 to17, wherein the process comprises: a) providing a middle layer (b) comprising a track-etched membrane including a hydrophilic coating, a top layer (a) comprising at least one layer of porous 222647PEP/HCath 29 pre-filter material with pores having a pore size equal to or larger than the pore size of the track-etched membrane, and a bottom layer (c) comprising a porous flow distribution material; b) laminating the top layer (a) comprising at least one layer of a porous pre-filter material, the middle layer (b) comprising the track-etched membrane, and the bottom layer (c) comprising a porous flow distribution material together; c) optionally treating the obtained multi-layered membrane with a hydrophilic coating solution; and optionally drying the multi-layered membrane; or, alternatively, d) providing a track-etched membrane including a hydrophilic coating, a porous pre-filter material with pores having a pore size equal to or larger than the pore size of the track-etched membrane, and a porous flow distribution material; e) optionally treating the porous pre-filter material and/or the porous flow distribution material with a hydrophilic coating solution and drying the treated materials; f) stacking together at least one layer of porous pre-filter material from d) or e), a track-etched membrane from e), and a porous flow distribution material from d) or e); and g) laminating the stacked layers from f) together.
  19. 19. The process according to claim 18, wherein laminating of steps b) or g) comprises applying pressure of 1 to 5 bar, preferably 2 to 3 bar, and a temperature of 120 to 180°C, preferably 130 to 160°C, more preferably 135 to 155°C.
  20. 20. The process according to 18 or 19, wherein in steps c) or e), respectively, an aqueous solution of polyvinyl pyrrolidone or a sulfonated coating, a coating containing alcoholic and carboxylic groups is applied, preferably a polyvinyl pyrrolidone solution at a concentration of 0.1 to 50 g/L. 222647PEP/HCath 30

Description

222647PEP/HCath 1 Multi-layered Membrane The present invention relates to a multi-layered membrane comprising at least one layer of a porous pre-filter material, a track-etched membrane and a layer comprising a porous flow distribution material, a process for preparation of such a multi-layered membrane as well as the use of such membranes for the separation of cells or other larger items from fluid, especially from body fluids and more specifically for the separation of blood into blood cells and serum or plasma. Background and Prior Art Track-etched membranes (TEM) have been considered suitable for cell separation due to their uniform pore size and smooth surface for a long time. The even surface of these membranes minimizes cell damage, as cells are gently retained on the surface rather than being trapped in rough structures or narrow pores. The uniform pore size of TEM can be precisely selected according to the size of the particles to be separated, ensuring the retention of such particles and cells on the membrane surface enabling effective separation. Unlike other filter materials such as expanded PTFE or sintered materials with sponge-like or tapered pores that potentially allow particles (e.g. cells) to enter and clog, the structure of TEM prevents particles from lodging in the pores, which reduces clogging and facilitates cleaning, thus enabling long-lasting use. To facilitate the efficient passage of liquids through the membrane, the surface must be wettable. Materials such as polyethylene terephthalate (PET) are naturally somewhat hydrophilic, while polycarbonate (PC) can be made hydrophilic by applying a coating. In any case, applying a hydrophilic coating onto the membrane supports the wetting and, thus, the fast separation of blood cells from whole blood. 222647PEP/HCath 2 Another challenge separating blood components is blood clotting or drying of body fluids. If the separation process takes too long, clots or residues may block membrane pores, thereby stopping the flow of plasma, serum, or other fluids through the membrane. WO 2024/056252 proposes membrane filters that promise reduced clotting. However, these or technically similar filters would greatly benefit from an improved flow of liquid during filtration. The objective of the present invention is therefore to provide materials that facilitate a rapid and even fluid flow through the filter membrane, preferably without relying on external forces such as pressure or vacuum. Summary of the Invention The object has been solved by the present invention as defined in the appended claims. According to a first aspect, the present invention provides a multi-layered membrane comprising: (a) a top layer comprising at least one layer of porous pre-filter material having pores having a pore size equal to or larger than the pore size of the track-etched membrane (b); (b) a middle layer comprising a track-etched membrane; and (c) a bottom layer comprising a porous flow distribution material, wherein the multi-layered membrane includes preferably a hydrophilic coating on at least the track-etched membrane. The top layer (a) diffuses the whole blood sample and retains red and white blood cells, the middle layer (b) separates the sample by size, and the bottom layer (c) holds and/or distributes the obtained plasma, optionally transferring the plasma to a detection device, e.g., a microfluidic device or lateral flow detection device. 222647PEP/HCath 3 According to a second aspect a process for the preparation of a multi-layered membrane is provided, wherein the process comprises: a) providing a middle layer (b) comprising a track-etched membrane including a hydrophilic coating, a top layer (a) comprising at least one layer of porous pre-filter material with pores having a pore size equal to or larger than the pore size of the track-etched membrane, and a bottom layer (c) comprising a porous flow distribution material; b) laminating the top layer (a) comprising at least one layer of a porous pre-filter material, the middle layer (b) comprising the track-etched membrane, and the bottom layer (c) comprising a porous flow distribution material together; c) optionally treating the obtained multi-layered membrane with a hydrophilic coating solution; and optionally drying the multi-layered membrane; or, alternatively, d) providing a track-etched membrane including a hydrophilic coating, a porous pre-filter material with pores having a pore size equal to or larger than the pore size of the track-etched membrane, and a porous flow distribution material; e) optionally treating the porous pre-filter material and/or the porous flow distribution material with a hydrophilic coating solution and drying the treated materials; f) stacking together at least one layer of porous pre-filter material from d) or e), a track-etched membrane from e), and a porous flow distribution material from d) or e); and g) laminating the stacked layers from f) together. In a third aspe