Membrane for use with implantable devices

• US 20030023317A1
• Filed: 07/27/2001
• Published: 01/30/2003
• Est. Priority Date: 07/27/2001
• Status: Active Grant

• Current Assignee: DexCom Incorporated
• Original Assignee: DexCom Incorporated
• Inventors: Shults, Mark C., Brauker, James H., Tapsak, Mark A.
• Granted Patent: US 6,702,857 B2
• Time in Patent Office: Days
• US Class Current: 623/23.76
• CPC Class Codes: A61B 2562/02 Details of sensors specially adapted for in-vivo measurements
• CPC Class Codes: A61B 5/076 Permanent implantations telemetry using implanted circuitry A61B5/0031; implanted stimulators for therapy A61N1/3605, A61N1/362, A61N1/372
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/14546 for measuring analytes not otherwise provided for, e.g. ions, cytochromes
• CPC Class Codes: A61B 5/14735 comprising an immobilised reagent
• CPC Class Codes: A61B 5/14865 invasive, e.g. introduced into the body by a catheter or needle or using implanted sensors
• CPC Class Codes: A61L 31/10 Macromolecular materials
• CPC Class Codes: A61L 31/14 Materials characterised by their function or physical properties , e.g. injectable or lubricating compositions, shape-memory materials, surface modified materials
• CPC Class Codes: Y10T 428/249921 Web or sheet containing structurally defined element or component

Abstract

The present invention provides a biointerface membrane for use with an implantable device that interferes with the formation of a barrier cell layer including; a first domain distal to the implantable device wherein the first domain supports tissue attachment and interferes with barrier cell layer formation and a second domain proximal to the implantable device wherein the second domain is resistant to cellular attachment and is impermeable to cells. In addition, the present invention provides sensors including the biointerface membrane, implantable devices including these sensors or biointerface membranes, and methods of monitoring glucose levels in a host utilizing the analyte detection implantable device of the invention. Other implantable devices which include the biointerface membrane of the present invention, such as devices for cell transplantation, drug delivery devices, and electrical signal delivery or measuring devices are also provided.

Claims

1. A biointerface membrane for use with an implantable device comprising;

a) a first domain distal to said implantable device wherein said first domain supports tissue ingrowth and interferes with barrier-cell layer formation and

b) a second domain proximal to said implantable device wherein said second domain is resistant to cellular attachment and is impermeable to cells and cell processes.

2. A biointerface membrane according to claim 1 wherein said first domain is comprised of an open-cell configuration having cavities and a solid portion.

3. A biointerface membrane according to claim 2 wherein said open-cell configuration comprises a depth of greater than one cavity in three dimensions substantially throughout the entirety of the domain.

4. A biointerface membrane according to claim 2 wherein a substantial number of said cavities are not less than 20 microns in the shortest dimension and not more than 1000 microns in the longest dimension.

5. A biointerface membrane according to claim 2 wherein a substantial number of said cavities are not less than 25 microns in the shortest dimension and not more than 500 microns in the longest dimension.

6. A biointerface membrane according to claim 2 wherein said cavities and cavity interconnections are formed in layers having different cavity dimensions.

7. A biointerface membrane according to claim 2 wherein said solid portion has not less than 5 microns in a substantial number of the shortest dimensions and not more than 2000 microns in a substantial number of the longest dimensions.

8. A biointerface membrane according to claim 2 wherein said solid portion has not less than 10 microns in a substantial number of the shortest dimensions and not more than 1000 microns in a substantial number of the longest dimensions.

9. A biointerface membrane according to claim 2 wherein said solid portion has not less than 10 microns in a substantial number of the shortest dimensions and not more than 400 microns in a substantial number of the longest dimensions.

10. A biointerface membrane according to claim 2 wherein said solid portion comprises silicone.

11. A bio interface membrane according to claim 2 wherein said solid portion comprises polyurethanes.

12. A biointerface membrane according to claim 2 wherein said solid portion comprises block copolymers.

13. A biointerface membrane according to claim 2 wherein said solid portion is made of a material selected from the group consisting of polytetrafluoroethylene, polyethylene-co-tetrafluoroethylene, polyolefins, polyesters, and polycarbonates.

14. A biointerface membrane according to claim 2 wherein said solid portion comprises non-woven fibers.

15. A biointerface membrane according to claim 14 wherein said solid portion is comprised of non-woven fibers greater than 5 microns in the shortest dimension.

16. A biointerface membrane according to claim 14 wherein said solid portion is comprised of non-woven fibers of about 10 microns in the shortest dimension.

17. A biointerface membrane according to claim 14 wherein said solid portion is comprised of non-woven fibers greater than or equal to 10 microns in the shortest dimension.

18. A biointerface membrane according to claim 14 wherein said solid portion is comprised of non-woven fibers greater than 10 microns in the shortest dimension.

19. A biointerface membrane according to claim 14 wherein said solid portion is comprised of polytetrafluoro ethylene.

20. A biointerface membrane according to claim 14 wherein said solid portion is comprised of polyolefins.

21. A biointerface membrane according to claim 14 wherein said solid portion is comprised of polyesters.

22. A biointerface membrane according to claim 14 wherein said solid portion is comprised of polycarbonates.

23. A biointerface membrane according to claim 1 wherein said second domain is composed of a biostable material.

24. A biointerface membrane according to claim 23 wherein said biostable material is comprised of a polyurethane and a hydrophilic polymer.

25. A biointerface membrane according to claim 23 wherein said biostable material is polyurethane comprising polyvinylpyrrolidone.

26. A biointerface membrane according to claim 23 wherein said second domain is polyurethane comprising not less than 5 weight percent polyvinylpyrrolidone and not more than 45 weight percent polyvinylpyrrolidone.

27. A biointerface membrane according to claim 23 wherein said second domain is polyurethane comprising not less than 20 weight percent polyvinylpyrrolidone and not more than 35 weight percent polyvinylpyrrolidone.

28. A biointerface membrane according to claim 23 wherein said second domain is polyurethane comprising about 27 weight percent polyvinylpyrrolidone.

31. A sensor head for use in an implantable device comprising a biointerface membrane according to claim 1.

32. An analyte measuring device comprising a biointerface membrane according to claim 1.

33. A cell transplantation device comprising a biointerface membrane according to claim 1.

34. A drug delivery device comprising a biointerface membrane according to claim 1.

35. An implantable drug delivery device according to claim 34 wherein said drug delivery device is selected from the group consisting of a pump, a microcapsule and a macrocapsule.

36. An electrical signal measuring device comprising a biointerface membrane according to claim 1.

37. An electrical pulse delivering device comprising a biointerface membrane according to claim 1.

38. An implantable device for measuring an analyte in a biological fluid, comprising:

a) a housing comprising electronic circuitry; and

b) at least one sensor head according to claim 31 operably connected to said electronic circuit means of said housing.

39. An implantable device according to claim 38, wherein said sensor head further comprises a member for determining the amount of glucose in a biological sample.

40. A method of monitoring analyte levels, comprising:

a) providing i) a host, and ii) an implantable device according to claim 38;

and

b) implanting said device in said host.

41. A method according to claim 40, wherein said implanting is subcutaneous.

42. A method of measuring analyte in a biological fluid, comprising:

a) providing i) a host, and ii) an implantable device according to claim 38 capable of accurate continuous analyte sensing; and

b) implanting said device in said host.

43. A method according to claim 42, wherein said implanting is subcutaneous.

29. A biointerface membrane comprising the properties of:

a) promoting tissue ingrowth into;

b) interfering with barrier cell formation on or within;

c) resisting barrier cell attachment to; and

d) blocking cell penetration into said membrane.

30. A biointerface membrane comprising at least two domains in combination that are adapted to:

a) permit tissue ingrowth into said membrane;

b) interfere with barrier cell formation on or within said membrane;

c) resist barrier cell attachment to said membrane; and

d) block cell penetration into said membrane.