Specialized hollow fiber membranes for in-vivo plasmapheresis and ultrafiltration

• US 7,195,711 B2
• Filed: 10/06/2004
• Issued: 03/27/2007
• Est. Priority Date: 04/13/2000
• Status: Expired due to Fees

• Current Assignee: Transvivo, Inc.
• Original Assignee: Transvivo, Inc.
• Inventors: Peters, Harold, Grage, Henry, Gorsuch, Reynolds G., Kearns, Jacob C., Handley, Harold Jr.
• Primary Examiner(s): KIM, SUN U
• Application Number:
  US10/959,918
• Publication Number:
  US 20050121384A1
• Time in Patent Office: 902 Days
• Field of Search: 210/483, 210/490, 210/500.23, 210/500.24, 210/500.41, 604/4.01, 604/5.01, 604/6.04, 604/6.09, 604/27
• US Class Current: 210/500.23
• CPC Class Codes: A61M 1/1678 intracorporal peritoneal dialysis A61M1/28
• CPC Class Codes: A61M 1/34 Filtering material out of the blood by passing it through a membrane, i.e. hemofiltration or diafiltration
• CPC Class Codes: A61M 1/3403 Regulation parameters
• CPC Class Codes: B01D 2325/0231 Dense layers being placed on the outer side of the cross-section
• CPC Class Codes: B01D 63/02 Hollow fibre modules
• CPC Class Codes: B01D 69/02 characterised by their properties
• CPC Class Codes: B01D 69/04 Tubular membranes
• CPC Class Codes: B01D 69/08 Hollow fibre membranes manufacture of hollow fibres D01D5/24, D01F1/08
• CPC Class Codes: B01D 71/68 Polysulfones; Polyethersulfones

Abstract

An in-vivo plasmapheresis and/or in-vivo ultrafiltration membrane comprises elongated hollow fibers each fiber having an interior lumen extending along the fiber length, the fiber wall having a plurality of zones between the inner and outer wall surfaces, each of the zones having a mass density different than the mass density of an adjacent zone. The fiber wall is characterized by having a lower mass density zone at the inner wall surface and a higher mass density zone at the outer wall surface. The fiber is further characterized by having an average elongation breaking force strength of at least about 0.2 lbs. and an average elongation of at least about 45%.

Claims

1. An in-vivo plasmapheresis and/or in-vivo ultrafiltration membrane comprising:

a plurality of elongated hollow fibers, each fiber comprising an outer wall, a higher mass density outer wall zone and an outer wall surface for being exposed to whole blood, wherein said higher mass density outer wall zone has a pore size capable of separating plasma and plasma components from whole blood by passing plasma and plasma components therethrough, and one or more lower mass density inner wall zones, an inner wall and an interior lumen extending along the length thereof and defined by an inner wall surface, and characterized by having an average elongation breaking force strength of at least about 0.2 lbs. and an average elongation of at least about 45%, and wherein the fiber wall structure is a continuous change in mass density from said outer wall surface to said inner wall surface and comprises a continuum of voids bounded by solid frames and substantially without macrovoids.

2. A membrane of claim 1 wherein said fiber wall has two mass density zones.

3. A membrane of claim 1 wherein said fiber wall has three mass density zones.

4. A membrane of claim 1 wherein fiber wall has four or more mass density zones.

5. A membrane of claim 1, 2, 3 or 4 wherein each of said mass density zones is characterized by a different average nominal pore size.

6. A membrane of claim 5 wherein said lower mass density inner wall zone is characterized by a nominal average pore diameter of between about 1 μ

m and about 60 μ

m.

7. A membrane of claim 5 wherein said higher mass density zone is characterized by a nominal average pore diameter of between about 0.10 μ

m and about 1 μ

m.

8. A membrane of claim 6 wherein said higher mass density zone is characterized by a nominal average pore diameter of between about 0.10 μ

m and about 1 μ

m.

9. A membrane of claim 5 wherein said higher mass density zone is characterized by a nominal average pore diameter of between about 0.003 μ

m and about 0.006 μ

m.

10. A membrane of claim 1, 2, 3 or 4 comprising polysulfone.

11. A membrane of claim 1, 2, 3 or 4 comprising polyethersulfone.

12. A membrane of claim 11 wherein said polyethersulfone is blended with polyethylene oxide and/or polyethylene glycol.

13. A membrane of claim 10 wherein said polysulfone is modified with polyethylene oxide-polyethylene glycol copolymer.

21. A membrane of claim 1 or 14 wherein said higher mass density is characterized by a nominal average pore diameter of between about 0.15 μ

m and about 1 μ

m.

22. A membrane of claim 21 wherein said lower mass density is characterized by a nominal average pore diameter of between about 5 μ

m and about 40 μ

m.

23. A membrane of claim 22 having a fluid flux (H₂O) of between about 1 ml/min/cm² and about 12 ml/min/cm² @100 mm Hg.

24. A membrane of claim 1 or 14 wherein said higher mass density is characterized by a nominal average pore diameter of between about 0.003 μ

m and about 0.006 μ

m.

25. A membrane of claim 24 wherein said lower mass density is characterized by a nominal average pore diameter of between about 5 μ

m and about 40 μ

m.

26. A membrane of claim 25 having a trans-membrane flux (H₂O) of between about 0.15 ml/min/cm² and about 2 ml/min/cm² @500 mm Hg.

14. An in-vivo plasmapheresis or in-vivo ultrafiltration membrane comprising a plurality of elongated hollow fibers, each fiber having an outer wall, an inner wall and an interior lumen extending along the length thereof and defined by an inner wall surface, the fiber wall characterized by a higher mass density adjacent to the outer wall and an outer wall surface for being exposed to whole blood and having a pore size capable of separating plasma and plasma components from whole blood by passing plasma and plasma components therethrough and a lower density adjacent to said inner wall, and wherein the fiber wall structure is a continuous change in mass density from said outer wall surface to said inner wall surface and comprises a continuum of voids bounded by solid frames and substantially without macrovoids, said fiber wall having an asymmetrical pore size and asymmetrical mass density between said inner wall surface and the outer wall surface, said fiber further characterized by having an average elongation breaking force strength of at least about 0.3 lbs. and an average elongation of at least about 45%.

15. A membrane of claim 14 wherein the higher mass density fiber wall is characterized by pores having a smaller average nominal pore size as compared to the average nominal pore size in the lower mass density fiber wall.

16. A membrane of claim 15 wherein said lower mass density is characterized by a nominal average pore diameter of between about 1 μ

m and about 60 μ

m.

17. A membrane of claim 15 or 16 wherein said higher mass density is characterized by a nominal average pore diameter of between about 0.10 μ

m and about 1 μ

m.

18. A membrane of claim 15 wherein said higher mass density is characterized by a nominal average pore diameter of between about 0.003 μ

m and about 0.006 μ

m.

19. A membrane of claim 18 wherein said lower mass density is characterized by a nominal average pore diameter of between about 1 μ

m and about 60 μ

m.

20. A membrane of claim 16 having a plasma trans-membrane flux of between about 0.5 ml/min/cm² and about 9 ml/min/cm² @ 100 mm Hg.

27. A membrane of claim 14 comprising a polyethersulfone.

28. A membrane of claim 27 wherein said polyethersulfone is blended with polyethylene oxide and/or polyethylene glycol.

29. A membrane of claim 14 comprising a polysulfone.

30. A membrane of claim 14 comprising polysulfone modified with polyethyleneoxide-polyethylene glycol copolymer.