NANOCLAY SORBENTS FOR DIALYSIS

• US 20100004588A1
• Filed: 07/01/2008
• Published: 01/07/2010
• Est. Priority Date: 07/01/2008
• Status: Active Grant

• Current Assignee: Baxter Healthcare SA (Baxter International Inc.), Baxter International Inc.
• Original Assignee: Baxter Healthcare SA (Baxter International Inc.), Baxter International Inc.
• Inventors: Xie, Wei, Ling, Michael T. K., Lo, Ying-Cheng, Yang, Hsinjin E., Yeh, Rosa H.
• Granted Patent: US 9,821,105 B2
• Time in Patent Office: Days
• US Class Current: 604/28
• CPC Class Codes: A61M 1/14 Dialysis systems; Artificial kidneys; Blood oxygenators semi-permeable membranes characterised by the material, manufacturing processes therefor B01D71/00 ; Reciprocating systems for treatment of body fluids, e.g. single needle systems for hemofiltration or pheresis
• CPC Class Codes: A61M 1/154 with sensing means or components thereof
• CPC Class Codes: A61M 1/155 with treatment-fluid pumping means or components thereof
• CPC Class Codes: A61M 1/1565 Details of valves
• CPC Class Codes: A61M 1/159 specially adapted for peritoneal dialysis
• CPC Class Codes: A61M 1/16 with membranes
• CPC Class Codes: A61M 1/1619 Sampled collection of used dialysate, i.e. obviating the need for recovery of whole dialysate quantity for post-dialysis analysis
• CPC Class Codes: A61M 1/1696 with dialysate regeneration
• CPC Class Codes: A61M 1/28 Peritoneal dialysis ; Other peritoneal treatment, e.g. oxygenation
• CPC Class Codes: A61M 1/284 Continuous flow peritoneal dialysis [CFPD]
• CPC Class Codes: A61M 1/30 Single needle dialysis ; Reciprocating systems, alternately withdrawing blood from and returning it to the patient, e.g. single-lumen-needle dialysis or single needle systems for hemofiltration or pheresis
• 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 1/3406 Physical characteristics of the filtrate, e.g. urea
• CPC Class Codes: A61M 1/3413 Diafiltration
• CPC Class Codes: A61M 1/3472 with treatment of the filtrate
• CPC Class Codes: A61M 1/3486 Biological, chemical treatment, e.g. chemical precipitation; treatment by absorbents
• CPC Class Codes: A61M 2202/0021 removed from and reintroduced into the body, e.g. after treatment
• CPC Class Codes: A61M 2202/0028 fluid entering a filter
• CPC Class Codes: A61M 2202/0078 changed by chemical action
• CPC Class Codes: A61M 2202/0498 Urea
• CPC Class Codes: A61M 2205/0211 : Ceramics
• CPC Class Codes: A61M 2205/12 : with interchangeable cassettes forming partially or totally the fluid circuit
• CPC Class Codes: A61M 2205/125 : with incorporated filters
• CPC Class Codes: A61M 2205/126 : with incorporated membrane filters
• CPC Class Codes: A61M 2205/15 : Detection of leaks
• CPC Class Codes: A61M 2205/3331 : Pressure; Flow
• CPC Class Codes: A61M 2205/3368 : Temperature
• CPC Class Codes: A61M 2205/50 : with microprocessors or computers
• CPC Class Codes: A61M 2205/75 : with filters
• CPC Class Codes: A61M 2209/088 : on the body
• CPC Class Codes: A61M 2210/1017 : Peritoneal cavity
• CPC Class Codes: B29C 48/09 : Articles with cross-sections having partially or fully enclosed cavities, e.g. pipes or channels
• CPC Class Codes: B29C 48/152 : the inner surfaces thereof

Abstract

Dialysis is enhanced by using nanoclay sorbents to better absorb body wastes in a flow-through system. Nanoclay sorbents, using montmorillonite, bentonite, and other clays, absorb significantly more ammonium, phosphate, and creatinine, and the like, than conventional sorbents. The clays may be used in wearable systems, such as a wearable peritoneal dialysis system, in which the dialysis fluid is circulated through a filter with nanoclay sorbents. Waste products are absorbed by the nanoclays and the dialysis fluid is recycled to the patient'"'"'s peritoneum. Using the ion-exchange capability of the nanoclays, waste ions in the dialysis fluid are replaced with desirable ions, such as calcium, magnesium, and bicarbonate. The nanoclay sorbents are also useful for refreshing dialysis fluid used in hemodialysis and thus reducing the quantity of dialysis fluid needed for hemodialysis.

Claims

1. A wearable system for removing body wastes from a fluid, comprising:

a closed fluid loop for circulating peritoneal dialysis fluid to and from a peritoneum of a patient;

at least one pump attached to the loop for circulating the peritoneal dialysis fluid into and out of the peritoneal cavity and through the fluid loop;

a replaceable cartridge housing having an inlet and an outlet, and at least one nanoclay within the housing for removing at least one body waste from the peritoneal dialysis fluid, wherein the nanoclay comprises a processed clay having at least one dimension from about 1 nm to about 200 nm; and

a drain container connected to the closed fluid system loop for removing excess fluid.

2. The wearable system according to claim 1, further comprising an access device for providing inflow and outflow to and from the peritoneum.

3. The wearable system according to claim 1, wherein the processed clay is selected from the group consisting of expanded clays, exfoliated clays, intercalated clays, and substituted clays.

4. The wearable system according to claim 1, wherein the processed nanoclay is selected from the group consisting of processed montmorillonite clay, processed bentonite clay, processed kaolin, processed talc, and processed vermiculite.

5. The wearable system according to claim 1, further comprising a sensor for measuring urea or a urea by-product in the dialysis fluid.

6. The wearable system according to claim 1, further comprising a filter attached to the fluid loop for removing particulates and debris from the peritoneal dialysis solution.

7. A wearable system for removing body wastes from a fluid, comprising:

a catheter having an inflow lumen and an outflow lumen in communication with a peritoneal cavity of the patient;

a fluid circuit for circulating peritoneal dialysis fluid to and from the peritoneal cavity;

a quantity of dialysate within the fluid circuit;

at least one pump attached to the fluid circuit for circulating the peritoneal dialysis fluid into and out of the peritoneal cavity and through the fluid circuit;

a replaceable cartridge housing having an inlet and an outlet, and at least one processed nanoclay within the housing for removing at least one body waste from the peritoneal dialysis fluid, wherein the nanoclay comprises a processed clay having at least one dimension from about 1 nm to about 200 nm;

a filter coupled to the fluid circuit for removing particulates and debris from the peritoneal dialysis fluid; and

a discharge path coupled to the fluid circuit allowing the peritoneal dialysis fluid to be drained after a treatment period.

8. The wearable system according to claim 7, wherein the processed nanoclay is selected from the group consisting of processed montmorillonite clay, processed bentonite clay, processed kaolin, processed talc, and processed vermiculite.

9. The wearable system according to claim 7, wherein the replaceable cartridge further comprises at least one of carbon, charcoal, and a zirconium compound.

10. The wearable system according to claim 7, wherein the processed nanoclay is a cationic ion exchange compound.

11. The wearable system according to claim 7, further comprising a controller and a connector block for controlling flows of fluid within the fluid circuit.

12. The wearable system according to claim 7, wherein the nanoclay has been chemically enhanced with an acid to increase its acidity or urea uptake.

13. A method for removing body wastes from a fluid, the method comprising:

circulating peritoneal dialysis fluid in a fluid circuit that includes a peritoneal cavity of a patient and a wearable dialysis system;

absorbing wastes from the peritoneum during a dwell time within the peritoneum;

pumping dialysis fluid from the peritoneum with a wearable pump forming part of the wearable dialysis system;

removing wastes from the peritoneal dialysis fluid with a sorbent cartridge that includes at least one processed nanoclay having at least one dimension from about 1 nm to about 200 nm; and

recirculating the peritoneal dialysis to the peritoneal cavity of the patient after the step of removing.

14. The method of claim 13, further comprising exchanging at least one cation of the processed nanoclay for ammonium from the dialysis fluid after the step of pumping.

15. The method of claim 13, further comprising exchanging at least one anion of the processed nanoclay for phosphate ion from the dialysis fluid after the step of pumping.

16. The method of claim 13, further comprising filtering particulates and debris from the peritoneal dialysis fluid.

17. The method of claim 13, wherein the step of removing wastes with a sorbent cartridge includes removing wastes using at least one of urease, zirconium oxide, zirconium phosphate, and zirconium carbonate.

18. The method of claim 13, further comprising checking a concentration of urea or a urea by-product in the dialysis fluid.

19. The method of claim 13, further comprising detecting a concentration of urea or a urea by-product with a calorimetric method.

20. A method for removing body waste of a patient, the method comprising:

providing a volume of peritoneal dialysis solution;

pumping the peritoneal dialysis solution into a peritoneal cavity of the patient;

pumping the peritoneal dialysis fluid from the peritoneal cavity using a wearable pump of a wearable peritoneal dialysis system to a wearable cartridge;

removing wastes from the peritoneal dialysis fluid with the wearable cartridge using at least one processed nanoclay having at least one dimension from about 1 nm to about 200 nm;

exchanging at least one of ammonium ions and phosphate ions of the peritoneal dialysis fluid for ions of the processed nanoclay;

recirculating the peritoneal dialysis to the peritoneal cavity of the patient after the step of removing; and

filtering particulates and debris from the peritoneal dialysis fluid with a wearable filter during one of the steps of pumping or recirculating.

21. The method of claim 20, wherein the step of exchanging comprises regeneration of the peritoneal dialysis fluid by removing waste ammonium and phosphate ions and adding ions of at least one of calcium, magnesium, chloride and lactate.

22. The method of claim 20, filtering bacteria and microorganisms from the peritoneal dialysis solution using a wearable antimicrobial filter.

23. The method of claim 20, further comprising converting urea in the dialysis fluid to ammonium ion using urease in the wearable cartridge.

24. The method of claim 20, wherein the processed nanoclay has an enhanced ammonium adsorption capacity caused by an increase in acidity of the nanoclay or addition of an enhancing agent.

25. The method of claim 20, wherein the wearable cartridge includes hollow fibers with nanoclay particles embedded in the walls of the fibers or with nanoclay particles within a lumen of the fibers.

26. The method of claim 20, wherein the wearable cartridge includes hollow fibers manufactured with nanoclay particles within a lumen of the fibers.

27. The method of claim 20, wherein the processed nanoclay has been treated with a compound including glyoxal or a glyoxal group to enhance an uptake of molecules with an amine functional group.

28. The method of claim 20, wherein the processed nanoclay has been treated with a compound, selected from the group consisting of phenylglyoxal, 4′

-(trifluoromethyl)phenylglyoxal, 2′

-chlorophenylglyoxal, 2′

-4′

-dimethlylphenylglyoxal and 2′

-fluorophenylglyoxal, to enhance an uptake of molecules with an amine functional group.

29. A wearable replaceable cartridge, comprising:

a housing having an inlet and an outlet, the housing suitable for wearing by person; and

at least one processed nanoclay within the housing for removing at least one body waste from a fluid, wherein the nanoclay comprises a processed clay having at least one dimension from about 1 nm to about 200 nm.

30. The wearable replaceable cartridge of claim 29, wherein the fluid comprises a peritoneal dialysis fluid.

31. The wearable replaceable cartridge of claim 29, wherein the processed nanoclay comprises at least one of a smectite, a kaolin, an illite, a chlorite, an attapulgite, and a combination of one or more of these.

32. The wearable replaceable cartridge of claim 29, wherein the processed nanoclay comprises swellable nanoclays selected from the group consisting of smectite nanoclays, sepiolite nanoclays, zeolite nanoclays, palygorskite nanoclays, and mixtures thereof.

33. The wearable replaceable cartridge of claim 29, wherein the processed nanoclay comprises a layered clay selected from the group consisting of a montmorillonite, a bentonite, a pyrophyllite, a hectorite, a saponite, a sauconite, a nontronite, talc, a beidellite, a volchonskoite, a stevensite, and vermiculite.

34. The wearable replaceable cartridge of claim 29, further comprising at least one of carbon, charcoal and activated charcoal.

35. The wearable replaceable cartridge of claim 29, further comprising a sensor for detecting ammonia or an ammonia by-product in dialysis fluid used in removing the body waste.

36. A method of making hollow fibers, the method comprising:

preparing a spinning solution of a polymer for a hollow fiber;

preparing an infusing slurry of nanoparticles, a solvent used in the spinning solution and water;

extruding the spinning solution through nozzles of a spinneret to form a hollow fiber;

extruding the infusing slurry through a center of the spinneret into a lumen of the hollow fiber;

sending the hollow fiber into a coagulation bath;

gathering the hollow fiber, wherein the nanoparticles are within the lumen of the hollow fiber; and

partially drying said hollow fiber.

37. The method of claim 36, further comprising:

cutting the hollow fiber into a plurality of lengths;

forming a filter by potting ends of the plurality of lengths; and

placing the filter into a housing.

38. The method of claim 36, wherein the spinning solution comprises a hydrophobic polymer, a hydrophilic polymer, a solvent for the hydrophobic polymer and the hydrophilic polymer, and a coagulant for the hydrophobic polymer.

39. The method of claim 36, wherein the polymer comprises a polysulfone and the spinning solution further comprises polyvinylpyrrolidone (PVP) or a modified PVP, a solvent for both the polysulfone and the PVP or modified PVP, and a small amount of coagulant additive.

40. The method of claim 36, wherein the spinning solution includes dimethylacetamide solvent and the infusing slurry includes dimethylacetamide and water.

41. A method for refreshing and renewing dialysis fluid, the method comprising:

providing a filter with processed nanoclay particles having at least one dimension from about 1 nm to about 200 nm;

flowing a used dialysis fluid through the filter;

absorbing waste product ions from the dialysis fluid by the processed nanoclay; and

replacing the waste product ions with ions from the processed nanoclay particles to refresh and renew the dialysis fluid, wherein the refreshed and renewed dialysis fluid is capable of reuse as a dialysis fluid.

42. The method of claim 41, wherein the dialysis fluid is hemodialysis fluid.

43. The method of claim 41, wherein the filter used for refreshing and renewing the dialysis fluid comprises hollow fibers, and wherein the processed nanoclay particles are contained within a wall or a lumen of the fibers.

44. The method of claim 41, wherein the ions from the processed nanoclay particles are selected from the group consisting of sodium, calcium, potassium, magnesium, chloride, acetate, bicarbonate and lactate.

45. The method of claim 41, further comprising testing the used dialysis fluid for a concentration of a waste product.