MEMBRANE FOR USE WITH IMPLANTABLE DEVICES

• US 20100087724A1
• Filed: 12/08/2009
• Published: 04/08/2010
• Est. Priority Date: 07/27/2001
• Status: Active Grant

• Current Assignee: DexCom Incorporated
• Original Assignee: DexCom Incorporated
• Inventors: Brauker, James H., Tapsak, Mark A., Shults, Mark
• Granted Patent: US 8,840,552 B2
• Time in Patent Office: Days
• US Class Current: 600/365
• 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. An implantable sensor, the sensor comprising:

an analyte measuring device configured to measure an analyte concentration in a host;

a sensing membrane located over the analyte measuring device; and

a biointerface membrane located over the sensing membrane, wherein the biointerface membrane comprises a fibrous barrier-cell disruptive domain and a non-fibrous domain, wherein the fibrous barrier-cell disruptive domain is configured to support tissue ingrowth and to allow cells and cell processes to pass therethrough, wherein the non-fibrous domain is adjacent to the fibrous barrier-cell disruptive domain, and wherein the non-fibrous domain is permeable to analytes and is impermeable to cells or cell processes.

2. The sensor of claim 1, wherein the sensing membrane contains an enzyme.

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

4. The sensor of claim 1, wherein the fibrous barrier-cell disruptive domain comprises non-woven fibers that are greater than about 5 microns in a shortest dimension.

5. The sensor of claim 1, wherein the fibrous barrier-cell disruptive domain comprises non-woven fibers that are greater than or equal to about 10 microns in a shortest dimension.

6. The sensor of claim 1, wherein the fibrous barrier-cell disruptive domain comprises non-woven fibers comprising at least one polymer selected from the group consisting of polypropylene, polyvinylchloride, polyvinylidene fluoride, polybutylene terephthalate, polymethylmethacrylate, polyether ether ketone, polyurethanes, cellulosic polymers, polysulfones, block copolymers thereof, and combinations thereof.

7. The sensor of claim 1, wherein the fibrous barrier-cell disruptive domain comprises non-woven fibers comprising at least one polymer selected from the group consisting of polyolefin, polyester, polycarbonate, polytetrafluoroethylene, block copolymers thereof, and combinations thereof.

8. The sensor of claim 1, wherein a thickness of the fibrous barrier-cell disruptive domain is not less than about 20 microns and not more than about 2000 microns.

9. The sensor of claim 1, wherein the non-fibrous domain is substantially non-adhesive for cells.

10. The sensor of claim 1, wherein the fibrous barrier-cell disruptive domain comprises a hydrophobic portion and a hydrophilic portion.

12. The implantable device of claim 1, wherein the membrane has a thickness of from about 10 microns to about 100 microns.

13. The implantable device of claim 1, wherein the membrane is configured to provide an interface with a biological fluid.

14. The implantable device of claim 1, wherein the membrane is configured to prevent barrier cell formation.

15. The implantable device of claim 1, wherein the membrane further comprises an enzyme.

16. The implantable device of claim 1, wherein the long period of time is about a month.

17. The implantable device of claim 1, wherein the long period of time is about a year.

11. An implantable device for continuous measurement of an analyte concentration, comprising:

a sensing region configured to continuously measure a signal associated with an analyte concentration in a host; and

a membrane located over the sensing region, wherein the membrane comprises a first copolymer comprising a silicone segment and a polyvinylpyrrolidone segment and a second copolymer comprising a polycarbonate-based polyurethane;

wherein the device is configured to achieve a level of accuracy corresponding to having, over a long period of time, 90% of measured analyte values within an “

A”

region and a “

B”

region of a standard Clarke error grid when sensor measurements are compared to a standard reference measurement; and

wherein the membrane is resistant to cellular attachment.

18. An implantable device for continuous measurement of an analyte concentration, comprising:

a sensing region configured to continuously measure a signal associated with an analyte concentration in a host; and

a membrane located over the sensing region, wherein the membrane comprises a first copolymer comprising a silicone segment and a polyvinylpyrrolidone segment and a second copolymer comprising a polycarbonate-based polyurethane;

wherein the device is configured to achieve a level of accuracy corresponding to having, after 12 weeks in vivo, 90% of measured analyte values within an “

A”

region and a “

B”

region of a standard Clarke error grid when sensor measurements are compared to a standard reference measurement; and

wherein the membrane is resistant to cellular attachment.