ZWITTERION SURFACE MODIFICATIONS FOR CONTINUOUS SENSORS

• US 20140094671A1
• Filed: 02/27/2013
• Published: 04/03/2014
• Est. Priority Date: 09/28/2012
• Status: Active Grant

• Current Assignee: DexCom Incorporated
• Original Assignee: DexCom Incorporated
• Inventors: Boock, Robert J., Dring, Chris W.
• Granted Patent: US 9,788,765 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 5/14546 for measuring analytes not otherwise provided for, e.g. ions, cytochromes
• CPC Class Codes: A61B 5/1486 using enzyme electrodes, e.g. with immobilised oxidase
• CPC Class Codes: A61B 5/14865 invasive, e.g. introduced into the body by a catheter or needle or using implanted sensors

Abstract

Devices are provided for measurement of an analyte concentration, e.g., glucose in a host. The device can include a sensor configured to generate a signal associated with a concentration of an analyte; and a sensing membrane located over the sensor. The sensing membrane comprises a diffusion resistance domain configured to control a flux of the analyte therethrough. The diffusion resistance domain comprises one or more zwitterionic compounds and a base polymer comprising both hydrophilic and hydrophobic regions.

Claims

1. A device for measurement of an analyte concentration, the device comprising:

a sensor configured to generate a signal associated with a concentration of an analyte; and

a sensing membrane located over the sensor, the sensing membrane comprising a diffusion resistance domain configured to control a flux of the analyte therethrough, wherein the diffusion resistance domain comprises a base polymer and one or more zwitterionic compounds, and wherein the base polymer comprises both hydrophilic and hydrophobic regions.

2. The device of claim 1, wherein an amount of the one or more zwitterionic compounds in the diffusion resistance domain is less than about 10% wt. of the resistance domain.

3. The device of claim 1, wherein an amount of the one or more zwitterionic compounds in the diffusion resistance domain is less than about 5% wt. of the resistance domain.

4. The device of claim 1, wherein the one or more zwitterionic compounds comprise a betaine compound or derivative thereof.

5. The device of claim 1, wherein the one or more zwitterionic compounds comprise at least one compound selected from the group consisting of a carboxyl betaine compound, a sulfo betaine compound, a phosphor betaine compound, and derivatives thereof.

6. The device of claim 1, wherein the one or more zwitterionic compounds comprise at least one compound selected from the group consisting of cocamidopropyl betaine, oleamidopropyl betaine, octyl sulfobetaine, caprylyl sulfobetaine, lauryl sulfobetaine, myristyl sulfobetaine, palmityl sulfobetaine, stearyl sulfobetaine, betaine (trimethylglycine), octyl betaine, phosphatidylcholine, glycine betaine, poly(carboxybetaine), poly(sulfobetaine), and derivatives thereof.

7. The device of claim 1, wherein the one or more zwitterionic compounds comprise at least one compound selected from the group consisting of poly(carboxybetaine), poly(sulfobetaine), and derivatives thereof.

8. The device of claim 1, wherein the sensing membrane further comprises an enzyme domain comprising an enzyme selected from the group consisting of glucose oxidase, glucose dehydrogenase, galactose oxidase, cholesterol oxidase, amino acid oxidase, alcohol oxidase, lactate oxidase, and uricase.

9. The device of claim 8, wherein the enzyme is glucose oxidase.

10. The device of claim 1, wherein the base polymer comprises at least one polymer selected from the group consisting of epoxies, polyolefins, polysiloxanes, polyethers, acrylics, polyesters, carbonates, and polyurethanes.

11. The device of claim 10, where the polyurethane is a polyurethane copolymer.

12. The device of claim 1, wherein the base polymer is a polyurethane.

13. The device of claim 1, wherein the sensor comprises an electrode.

14. The device of claim 1, wherein the device is configured for continuous measurement of an analyte concentration.

15. The device of claim 1, wherein the analyte is glucose.

16. The device of claim 1, wherein the diffusion resistance domain is a unitary bioprotective/diffusion resistance domain.

17. A device for measurement of an analyte concentration, the device comprising:

a sensor configured to generate a signal associated with a concentration of an analyte; and

a sensing membrane located over the sensor, wherein a surface of the sensing membrane most distal to the sensor is coated with a coating comprising one or more zwitterionic compounds.

18. The device of claim 17, wherein the surface of the sensing membrane most distal to the sensor comprises surface-active end groups configured for cross-linking with the one or more zwitterionic compounds, and wherein the one or more zwitterionic compounds are cross-linked to the surface-active end groups.

19. The device of claim 17, wherein the coating on the surface of the sensor membrane is not a hydrogel.

20. The device of claim 17, wherein the one or more zwitterionic compounds comprise a betaine compound or derivative thereof.

21. The device of claim 17, wherein the one or more zwitterionic compounds comprise at least one compound selected from the group consisting of a carboxyl betaine compound, a sulfo betaine compound, a phosphor betaine compound, and derivatives thereof.

22. The device of claim 17, wherein the one or more zwitterionic compounds comprise one or more compounds selected from the group consisting of cocamidopropyl betaine, oleamidopropyl betaine, octyl sulfobetaine, caprylyl sulfobetaine, lauryl sulfobetaine, myristyl sulfobetaine, palmityl sulfobetaine, stearyl sulfobetaine, betaine (trimethylglycine), octyl betaine, phosphatidylcholine, glycine betaine, poly(carboxybetaine), poly(sulfobetaine), and derivatives thereof.

23. The device of claim 17, wherein the one or more zwitterionic compounds comprise one or more compounds selected from the group consisting of poly(carboxybetaine), poly(sulfobetaine), and derivatives thereof.

24. The device of claim 20, wherein the betaine compound or derivative thereof is a hydrolyzable cationic ester of a betaine.

25. The device of claim 24, wherein the hydrolyzable cationic ester of a betaine is a cationic poly(carboxybetaine) ester.

26. The device of claim 17, wherein the sensing membrane further comprises an enzyme domain comprising an enzyme selected from the group consisting of glucose oxidase, glucose dehydrogenase, galactose oxidase, cholesterol oxidase, amino acid oxidase, alcohol oxidase, lactate oxidase, and uricase.

27. The device of claim 26, wherein the enzyme is glucose oxidase.

28. The device of claim 17, wherein the sensor membrane comprises a bioprotective domain located most distal to the sensor, and wherein the bioprotective domain comprises at least one polymer selected from the group consisting of epoxies, polyolefins, polysiloxanes, polyethers, acrylics, polyesters, carbonates, and polyurethanes.

29. The device of claim 28, wherein the polyurethane is a polyurethane copolymer.

30. The device of claim 28, wherein the base polymer is a polyurethane.

31. The device of claim 17, wherein the sensor membrane comprises a unitary bioprotective/diffusion resistance domain comprising at least one polymer selected from the group consisting of epoxies, polyolefins, polysiloxanes, polyethers, acrylics, polyesters, carbonates, and polyurethanes.

32. The device of claim 17, wherein the sensor comprises an electrode.

33. The device of claim 17, wherein the device is configured for continuous measurement of an analyte concentration.

34. The device of claim 17, wherein the analyte is glucose.