ANALYTE SENSOR

• US 20070197890A1
• Filed: 02/14/2007
• Published: 08/23/2007
• Est. Priority Date: 07/25/2003
• Status: Active Grant

• Current Assignee: DexCom Incorporated
• Original Assignee: DexCom Incorporated
• Inventors: Boock, Robert, Brister, Mark, Tapsak, Mark, Brauker, James, Petisce, James, Rixman, Monica, Simpson, Peter, Carr-Brendel, Victor
• Granted Patent: US 7,828,728 B2
• Time in Patent Office: Days
• US Class Current: 600/365
• CPC Class Codes: A61B 5/0031 Implanted circuitry
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• 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: A61B 5/418 lymph vessels, ducts or nodes

Abstract

The present invention relates generally to membranes utilized with implantable devices, such as devices for the detection of analyte concentrations in a biological sample. More particularly, the invention relates to novel silicone-hydrophilic polymer blend membranes, and to devices and implantable devices including these membranes.

Claims

1. An implantable analyte sensor, comprising:

a electroactive surface configured for insertion into a host'"'"'s body; and

a membrane system comprising a cell impermeable domain disposed between the electroactive surface and the host'"'"'s body when implanted;

wherein the cell impermeable domain comprises a silicone material configured to allow transport of an analyte therethrough.

2. The sensor of claim 1, wherein the membrane system comprises an enzyme domain positioned between the electroactive surface and the cell impermeable domain, wherein the enzyme domain comprises an enzyme.

3. The sensor of claim 2, wherein the enzyme domain comprises a silicone material.

4. The sensor of claim 2, wherein the enzyme domain comprises glucose oxidase.

5. The sensor of claim 1, wherein the membrane system further comprises a diffusion resistance domain.

6. The sensor of claim 5, wherein the diffusion resistance domain is positioned between the electroactive surface and the cell impermeable domain.

7. The sensor of claim 5, wherein the cell impermeable domain and the diffusion resistance domain comprise a unitary layer configured to control flux of the analyte therethrough.

8. The sensor of claim 5, wherein an analyte permeability of the cell impermeable domain is greater than an analyte permeability of the diffusion resistance domain.

9. The sensor of claim 5, wherein the diffusion resistance domain comprises a silicone material configured to control flux of the analyte therethrough.

10. The sensor of claim 5, wherein the cell impermeable domain exhibits an oxygen to analyte permeability ratio of at least about 50:

1.

11. The sensor of claim 5, wherein the cell impermeable domain exhibits an oxygen to analyte permeability ratio of at least about 200:

1.

12. The sensor of claim 1, wherein the silicone material comprises a blend of a silicone elastomer and a hydrophilic copolymer.

13. The sensor of claim 12, wherein the hydrophilic copolymer comprises hydroxy substituents.

14. The sensor of claim 12, wherein the hydrophilic copolymer comprises a poly(ethylene oxide)-poly(propylene oxide) copolymer.

15. The sensor of claim 12, wherein the hydrophilic copolymer comprises a poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) triblock polymer.

16. The sensor of claim 12, wherein the hydrophilic copolymer comprises a PLURONIC®

polymer.

17. The sensor of claim 12, wherein at least a portion of the hydrophilic copolymer is at least partially cross-linked.

18. The sensor of claim 12, wherein from about 1% w/w to about 50% w/w of the cell impermeable domain is the hydrophilic copolymer.

19. The sensor of claim 12, wherein from about 5% w/w to about 30% w/w of the cell impermeable domain is the hydrophilic copolymer.

20. The sensor of claim 12, wherein the silicone material has a micellar jacket structure.

21. The sensor of claim 1, wherein the analyte is glucose.

22. The sensor of claim 1, wherein the sensor is configured to be transcutaneously implanted.

23. The sensor of claim 1, wherein the sensor is configured to be intravascularly implanted.

24. The sensor of claim 1, wherein the sensor is configured to be wholly implanted.

25. The sensor of claim 1, wherein the sensor is configured to be extracorporeally implanted.

26. The sensor of claim 1, wherein the sensor comprises an architecture with at least one dimension less than about 1 mm.

27. The sensor of claim 1, wherein the electrode comprises a bulk metal or an electrically conductive wire.

28. The sensor of claim 1, wherein the membrane system further comprises an electrode domain positioned between the electroactive surface and the cell impermeable domain.

29. The sensor of claim 1, wherein the sensor has a variable stiffness.

30. The sensor of claim 1, wherein the silicone material comprises a silicone composition and a hydrophile.

31. The sensor of claim 30, wherein at least a portion of the hydrophile is covalently incorporated into the silicone material.

32. The sensor of claim 1, wherein the cell impermeable domain is configured to block passage therethrough of at least one interferent.

33. The sensor of claim 32, wherein the interferent comprises at least one substance selected from the group consisting of hydrogen peroxide, reactive oxygen species, and reactive nitrogen species.

34. The sensor of claim 32, wherein the interferent comprises at least one substance selected from the group consisting of acetaminophen, ascorbic acid, dopamine, ibuprofen, salicylic acid, tolbutamide, tetracycline, creatinine, uric acid, ephedrine, L-dopa, methyl dopa, and tolazamide.

35. The sensor of claim 32, wherein the cell impermeable domain is configured to substantially block passage therethrough of at least one non-constant noise causing interferent.