MULTIPLE-LAYER IMMUNE BARRIER FOR DONOR CELLS

• US 20110300191A1
• Filed: 06/06/2011
• Published: 12/08/2011
• Est. Priority Date: 06/07/2010
• Status: Active Grant

• Current Assignee: Beta-O2 Technologies Ltd.
• Original Assignee: Beta-O2 Technologies Ltd.
• Inventors: BARKAI, URIEL, ROTEM, AVI, BREMER, YEHEZKEL, NEUFELD, TOVA
• Granted Patent: US 9,446,168 B2
• Time in Patent Office: Days
• US Class Current: 424/400
• CPC Class Codes: A01N 1/0231 Chemically defined matrices, e.g. alginate gels, for immobilising, holding or storing cells, tissue or organs for preservation purposes; Chemically altering or fixing cells, tissue or organs, e.g. by cross-linking, for preservation purposes
• CPC Class Codes: A61K 35/39 Pancreas; Islets of Langerhans Langerhans cells of epidermis A61K35/36
• CPC Class Codes: A61K 9/0024 Solid, semi-solid or solidifying implants, which are implanted or injected in body tissue compositions for intravenous administration, normal injectable solutions or dispersions for, e.g. subcutaneous administration A61K9/0019; brain implants A61K9/0085; (coated) prostheses, catheters or stents A61L
• CPC Class Codes: A61K 9/1652 Polysaccharides, e.g. alginate, cellulose derivatives; Cyclodextrin homeopathic globules A61K9/1623
• CPC Class Codes: A61K 9/5073 having two or more different coatings optionally including drug-containing subcoatings
• CPC Class Codes: A61L 2400/18 Modification of implant surfaces in order to improve biocompatibility, cell growth, fixation of biomolecules, e.g. plasma treatment
• CPC Class Codes: A61L 2420/02 Methods for coating medical devices
• CPC Class Codes: A61L 2420/08 Coatings comprising two or more layers
• CPC Class Codes: A61L 2430/40 Preparation and treatment of biological tissue for implantation, e.g. decellularisation, cross-linking
• CPC Class Codes: A61L 27/00 Materials for grafts or prostheses or for coating grafts or prostheses dental prostheses A61C13/00; shape or structure of prostheses A61F2/00; use of preparations for artificial teeth A61K6/80; artificial kidneys A61M1/14
• CPC Class Codes: A61L 27/20 Polysaccharides
• CPC Class Codes: A61L 27/34 Macromolecular materials
• CPC Class Codes: A61L 27/36 containing ingredients of undetermined constitution or reaction products thereof , e.g. transplant tissue, natural bone, extracellular matrix isolated natural compounds, e.g. collagen A61L27/24
• CPC Class Codes: A61L 27/505 Stabilizers
• CPC Class Codes: A61L 27/56 Porous materials, e.g. foams or sponges
• CPC Class Codes: A61P 1/18 for pancreatic disorders, e.g. pancreatic enzymes
• CPC Class Codes: C12N 5/0012 Cell encapsulation
• CPC Class Codes: C12N 5/0676 Pancreatic cells
• CPC Class Codes: Y10S 623/915 Method or apparatus for preparing biological material

Abstract

A system is provided, including a plurality of donor cells and a first alginate structure that encapsulates the plurality of donor cells. The first alginate structure has a guluronic acid concentration of between 64% and 74%. The system additionally includes a second alginate structure that surrounds the first alginate structure, the second alginate structure having a mannuronic acid concentration of between 52% and 60%. A selectively-permeable membrane is coupled at least in part to the second alginate structure. Other embodiments are also described.

Claims

1. Apparatus, comprising:

a plurality of donor cells;

a first alginate structure that encapsulates the plurality of donor cells, the first alginate structure having a guluronic acid concentration of between 64% and 74%;

a second alginate structure that surrounds the first alginate structure, the second alginate structure having a mannuronic acid concentration of between 52% and 60%; and

a selectively-permeable membrane coupled at least in part to the second alginate structure.

2. The apparatus according to claim 1, wherein the selectively-permeable membrane surrounds the second alginate structure.

3. The apparatus according to claim 1, wherein the selectively-permeable membrane is embedded at least in part within the second alginate structure.

4. The apparatus according to claim 1, wherein the guluronic acid concentration of the first alginate structure is between 67% and 71%.

5. The apparatus according to claim 1, wherein the mannuronic acid concentration of the second alginate structure is between 54% and 58%.

6. The apparatus according to claim 1, wherein the plurality of donor cells comprise cells of pancreatic islets.

7. The apparatus according to claim 1, wherein the first alginate structure has a thickness of 300-700 um.

8. The apparatus according to claim 7, wherein the first alginate structure has a thickness of 400-700 um.

9. The apparatus according to claim 1, wherein the first alginate structure has a thickness of 500 um.

10. The apparatus according to claim 1, wherein the first alginate structure has a thickness of 600 um.

11. The apparatus according to claim 1, wherein the first alginate structure has a dry matter content of at least 1.8%.

12. The apparatus according to claim 11, wherein the first alginate structure has a dry matter content of at least 2.2%.

13. The apparatus according to claim 11, wherein the first alginate structure has a dry matter content of between 1.8 and 4.2%.

14. The apparatus according to claim 13, wherein the dry matter content of the first alginate structure is between 2.2 and 4.0%.

15. The apparatus according to claim 1, wherein the first alginate structure has a dry matter content of between 1.8 and 3.0%.

16. The apparatus according to claim 15, wherein the dry matter content of the first alginate structure is between 2.2 and 2.6%.

17. The apparatus according to claim 1, wherein the second alginate structure has a dry matter content of between 3.0 and 7.0%.

18. The apparatus according to claim 17, wherein the dry matter content of the second alginate structure is between 5.5 and 6.5%.

19. The apparatus according to claim 1, wherein the second alginate structure has a dry matter content of between 3.0 and 5.0%.

20. The apparatus according to claim 19, wherein the dry matter content of the second alginate structure is between 3.5 and 4.5%.

21. The apparatus according to claim 1, wherein the plurality of donor cells comprise cells that are disposed in a plurality of pancreatic islets, and wherein the first alginate structure encapsulates that plurality of pancreatic islets at a density of between 1000 and 6500 islet equivalents (IEQ) per square cm.

22. The apparatus according to claim 1, wherein the plurality of donor cells comprise cells that are disposed in a plurality of pancreatic islets, and wherein the first alginate structure encapsulates that plurality of pancreatic islets at a density of between 1500 and 6000 islets per square cm.

23. The apparatus according to claim 22, wherein the first alginate structure encapsulates that plurality of pancreatic islets at a density of between 3500 and 4500 islets per square cm.

24. The apparatus according to claim 1, wherein:

the second alginate structure has an inner surface that is in contact with an outer surface of the first alginate structure,

the apparatus has an external surface that is not in contact with the first alginate structure, and

a distance between the inner surface of the second alginate structure and the external surface of the apparatus is between 25 um and 50 um.

25. The apparatus according to claim 24, wherein the membrane is embedded within the second alginate structure, and the second alginate structure has an outer surface thereof which defines the external surface of the apparatus.

26. The apparatus according to claim 1, wherein a distance from an external surface of the apparatus to a center of the first alginate structure is 300-500 um.

27. The apparatus according to claim 26, wherein the distance from the external surface of the apparatus to the center of the first alginate structure is 350 um.

28. The apparatus according to claim 26, wherein the distance from the external surface of the apparatus to the center of the first alginate structure is 300 um.

29. The apparatus according to claim 26, wherein the membrane is embedded within the second alginate structure, and the second alginate structure has an outer surface thereof which defines the external surface of the apparatus.

30. The apparatus according to claim 1, wherein the selectively-permeable membrane has a pore size of up to 0.2 um.

31. A method for encapsulating a plurality of donor cells, comprising:

encapsulating the plurality of donor cells in a first alginate structure having a guluronic acid concentration of between 64% and 74%;

surrounding the first alginate structure by a second alginate structure having a mannuronic acid concentration of between 52% and 60%; and

surrounding the second alginate structure by a selectively-permeable membrane.

32. The method according to claim 31, wherein the guluronic acid concentration of the first alginate structure is between 67% and 71%, and wherein surrounding the plurality of donor cells in the first alginate structure comprises surrounding the plurality of cells in the first alginate structure having the guluronic acid concentration of between 67% and 71%.

33. The method according to claim 31, wherein the mannuronic acid concentration of the second alginate structure is between 54% and 58%, and wherein surrounding the first alginate structure by the second alginate structure comprises surrounding the first alginate structure by the second alginate structure having the mannuronic acid concentration of between 54% and 58%.

34. The method according to claim 31, wherein the plurality of donor cells include cells that are disposed in a plurality of pancreatic islets, and wherein encapsulating the plurality of donor cells in the first alginate structure comprises encapsulating the plurality of pancreatic islets in the first alginate structure at a density of between 1000 and 6500 islet equivalents (IEQ) per square cm.

35. The method according to 31, wherein the plurality of donor cells include cells that are disposed in a plurality of pancreatic islets, and wherein encapsulating the plurality of donor cells in the first alginate structure comprises encapsulating the plurality of pancreatic islets in the first alginate structure at a density of between 1500 and 6000 islets per square cm.

36. The method according to claim 35, wherein encapsulating the plurality of pancreatic islets in the first alginate structure comprises encapsulating the plurality of pancreatic islets in the first alginate structure at a density of between 3500 and 4500 islets per square cm.

37. Apparatus, comprising:

a plurality of donor cells;

a first alginate structure that encapsulates the plurality of donor cells, the first alginate structure having a distance from an outer surface thereof to a center of the first alginate structure, the distance being configured so as to attenuate diffusion toward the plurality of donor cells of molecules;

a second alginate structure that surrounds the first alginate structure, the second alginate structure having a structural composition selected so as to restrict passage therethrough of molecules having a molecular weight above and including 150 kDa; and

a selectively-permeable membrane coupled at least in part to the second alginate structure, the membrane being configured to restrict passage therethrough of cells.

38. The apparatus according to claim 37, wherein the first alginate structure is configured so as to attenuate diffusion toward the plurality of donor cells of negatively-charged molecules.

39. The apparatus according to claim 37, wherein the first alginate structure has a dry matter content of at least 1.8%.

40. The apparatus according to claim 39, wherein the first alginate structure has a dry matter content of at least 2.2%.

41. The apparatus according to claim 39, wherein the first alginate structure has a dry matter content of between 1.8 and 4.2%.

42. The apparatus according to claim 41, wherein the dry matter content of the first alginate structure is between 2.2 and 4.0%.

43. The apparatus according to claim 37, wherein the first alginate structure has a dry matter content of between 1.8 and 3.0%.

44. The apparatus according to claim 43, wherein the dry matter content of the first alginate structure is between 2.2 and 2.6%.

45. The apparatus according to claim 43, wherein the second alginate structure has a dry matter content of between 3.0 and 7.0%.

46. The apparatus according to claim 45, wherein the dry matter content of the second alginate structure is between 5.5 and 6.5%.

47. The apparatus according to claim 37, wherein the second alginate structure has a dry matter content of between 3.0 and 5.0%.

48. The apparatus according to claim 47, wherein the dry matter content of the second alginate structure is between 3.5 and 4.5%.

49. The apparatus according to claim 37, wherein the first alginate structure has a thickness of 300-700 um.

50. The apparatus according to claim 49, wherein the first alginate structure has a thickness of 400-700 um.

51. The apparatus according to claim 37, wherein the first alginate structure has a thickness of 500 um.

52. The apparatus according to claim 37, wherein:

the second alginate structure has an inner surface that is in contact with an outer surface of the first alginate structure,

the apparatus has an external surface that is not in contact with the first alginate structure, and

a distance between the inner surface of the second alginate structure and the external surface of the apparatus is between 25 um and 50 um.

53. The apparatus according to claim 52, wherein the membrane is embedded within the second alginate structure, and the second alginate structure has an outer surface thereof which defines the external surface of the apparatus.

54. The apparatus according to claim 37, wherein a distance from an external surface of the apparatus to a center of the first alginate structure is 300-500 um.

55. The apparatus according to claim 54, wherein the distance from the external surface of the apparatus to the center of the first alginate structure is 350 um.

56. The apparatus according to claim 54, wherein the distance from the external surface of the apparatus to the center of the first alginate structure is 300 um.

57. The apparatus according to claim 54, wherein the membrane is embedded within the second alginate structure, and the second alginate structure has an outer surface thereof which defines the external surface of the apparatus.