SILICONE BASED MEMBRANES FOR USE IN IMPLANTABLE GLUCOSE SENSORS

• US 20120035445A1
• Filed: 10/20/2011
• Published: 02/09/2012
• Est. Priority Date: 05/22/2002
• Status: Active Grant

• Current Assignee: DexCom Incorporated
• Original Assignee: DexCom Incorporated
• Inventors: Boock, Robert, Rixman, Monica
• Granted Patent: US 8,543,184 B2
• Time in Patent Office: Days
• US Class Current: 600/345
• 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 5/6848 Needles
• CPC Class Codes: C08G 77/12 containing silicon bound to hydrogen C08G77/045 takes precedence
• CPC Class Codes: C08G 77/20 containing silicon bound to unsaturated aliphatic groups C08G77/045 takes precedence
• CPC Class Codes: C08G 77/46 containing polyether sequences
• CPC Class Codes: C08L 2666/14 Macromolecular compounds according to C08L59/00 - C08L87/00; Derivatives thereof
• CPC Class Codes: C08L 83/04 Polysiloxanes

Abstract

Membrane systems incorporating silicone polymers are described for use in implantable analyte sensors. Some layers of the membrane system may comprise a blend of a silicone polymer with a hydrophilic polymer, for example, a triblock poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) polymer. Such polymeric blends provide for both high oxygen solubility and aqueous analyte solubility.

Claims

1. An implantable continuous analyte sensor, comprising:

a working electrode; and

a membrane disposed over at least a portion of the working electrode, the membrane comprising a blend, the blend comprising a silicone polymer and a hydrophilic polymer.

2. The implantable continuous analyte sensor of claim 1, wherein the silicone polymer is cross-linked with the hydrophilic polymer.

3. The implantable continuous analyte sensor of claim 1, wherein the hydrophilic polymer has a molecular weight of at least about 1,000 g/mol.

4. The implantable continuous analyte sensor of claim 1, wherein the hydrophilic polymer has a molecular weight of at least about 10,000 g/mol.

5. The implantable continuous analyte sensor of claim 1, wherein the hydrophilic polymer has a molecular weight of at least about 15,000 g/mol.

6. The implantable continuous analyte sensor of claim 1, wherein up to 25% of the silicone polymer is covalently linked to the hydrophilic polymer.

7. The implantable continuous analyte sensor of claim 1, wherein up to 15% of the silicone polymer is covalently linked to the hydrophilic polymer.

8. The implantable continuous analyte sensor of claim 1, wherein up to 5% of the silicone polymer is covalently linked to the hydrophilic polymer.

9. The implantable continuous analyte sensor of claim 1, wherein the hydrophilic polymer comprises a material selected from the group consisting of polyvinylpyrrolidone, polyhydroxyethyl methacrylate, polyvinylalcohol, polyacrylic acid, polyethers, and copolymers thereof.

10. The implantable continuous analyte sensor of claim 1, wherein the membrane is configured to inhibit transport of an interfering species therethrough.

11. The implantable continuous analyte sensor of claim 1, wherein the membrane is configured to reduce a flux of an analyte therethrough.

12. The implantable continuous analyte sensor of claim 1, wherein the membrane comprises an enzyme configured to react with an analyte.

13. The implantable continuous analyte sensor of claim 1, wherein the sensor is configured to be transcutaneously implanted.

14. The implantable continuous analyte sensor of claim 1, wherein the membrane further comprises a polyanionic polymer.

15. An implantable continuous analyte sensor, comprising:

a working electrode; and

a membrane disposed over the working electrode, the membrane comprising;

a first domain comprising a blend of a silicone polymer and a hydrophilic polymer;

a second domain comprising an enzyme configured to react with an analyte; and

a third domain comprising ionic components configured to reduce permeability of the third domain to an interfering species.

16. The implantable continuous analyte sensor of claim 15, wherein the first domain is positioned more distal to the working electrode than the second domain, and wherein the second domain is positioned more distal to the working electrode than the third domain.

17. The implantable continuous analyte sensor of claim 15, wherein the hydrophilic polymer comprises a material selected from the group consisting of polyvinylpyrrolidone, polyhydroxyethyl methacrylate, polyvinylalcohol, polyacrylic acid, polyethers, and copolymers thereof.

18. An implantable continuous analyte sensor, comprising:

a working electrode; and

a membrane system disposed over at least a portion of the working electrode, the membrane system comprising a first domain and a second domain, the first domain and the second domain each comprising a blend comprising a silicone polymer and a hydrophilic polymer, the first domain having a blend ratio of silicone polymer to hydrophilic polymer that is different than a blend ratio of silicone polymer to hydrophilic polymer of the second domain.

19. The implantable continuous analyte sensor of claim 18, wherein the first domain is less permeable to an interfering species than to an analyte.

20. The implantable continuous analyte sensor of claim 18, wherein the first domain is configured to provide a greater reduction of transport of an interfering species therethrough than the second domain.

21. An implantable continuous analyte sensor, comprising:

a working electrode; and

a membrane disposed over the working electrode, the membrane comprising;

a first domain configured to selectively reduce a permeability of a first interfering species therethrough;

a second domain comprising an enzyme configured to react with an analyte; and

a third domain configured to selectively reduce a permeability of a second interfering species therethrough.

22. The implantable continuous analyte sensor of claim 21, wherein the first domain comprises a blend comprising a silicone polymer and a hydrophilic polymer.

23. The implantable continuous analyte sensor of claim 22, wherein the third domain comprises ionic components configured to reduce a permeability of the third domain to the second interfering species.

24. The implantable continuous analyte sensor of claim 22, wherein the first interfering species is acetaminophen, and wherein the second interfering species is ascorbic acid.

25. The implantable continuous analyte sensor of claim 21, wherein the first domain is positioned more distal to the working electrode than the second domain, and wherein the second domain is positioned more distal to the working electrode than the third domain.