TECHNIQUES TO IMPROVE POLYURETHANE MEMBRANES FOR IMPLANTABLE GLUCOSE SENSORS

• US 20140378798A1
• Filed: 09/10/2014
• Published: 12/25/2014
• Est. Priority Date: 05/22/2002
• Status: Active Grant

• Current Assignee: DexCom Incorporated
• Original Assignee: DexCom Incorporated
• Inventors: Tapsak, Mark A., Rhodes, Rathbun K., Shults, Mark C., McClure, Jason D.
• Granted Patent: US 9,179,869 B2
• Time in Patent Office: Days
• US Class Current: 600/347
• CPC Class Codes: A61B 2562/028 Microscale sensors, e.g. electromechanical sensors [MEMS]
• CPC Class Codes: A61B 2562/125 characterised by the manufacture of electrodes
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/1473 invasive, e.g. introduced into the body by a catheter A61B5/1482 takes precedence
• 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
• CPC Class Codes: A61L 31/12 Composite materials, i.e. containing one material dispersed in a matrix of the same or different material
• CPC Class Codes: B01D 69/141 Heterogeneous membranes, e.g. containing dispersed material; Mixed matrix membranes
• CPC Class Codes: B01D 69/1411 containing dispersed material in a continuous matrix
• CPC Class Codes: B01D 71/54 Polyureas; Polyurethanes
• CPC Class Codes: B01D 71/80 Block polymers
• CPC Class Codes: B05D 3/007 After-treatment
• CPC Class Codes: B05D 5/00 Processes for applying liquids or other fluent materials to surfaces to obtain special surface effects, finishes or structures
• CPC Class Codes: C12Q 1/002 Electrode membranes
• CPC Class Codes: C12Q 1/006 for glucose
• CPC Class Codes: Y10T 428/31551 Of polyamidoester [polyurethane, polyisocyanate, polycarbamate, etc.]

Abstract

The invention provides an implantable membrane for regulating the transport of analytes therethrough that includes a matrix including a first polymer; and a second polymer dispersed throughout the matrix, wherein the second polymer forms a network of microdomains which when hydrated are not observable using photomicroscopy at 400× magnification or less. In one aspect, the homogeneous membrane of the present invention has hydrophilic domains dispersed substantially throughout a hydrophobic matrix to provide an optimum balance between oxygen and glucose transport to an electrochemical glucose sensor.

Claims

1. An implantable device for measuring an analyte in a hydrophilic body fluid, comprising:

(a) a polymeric membrane comprising (i) a matrix comprising a first polymer; and

(ii) a second polymer dispersed throughout said matrix, wherein said second polymer forms a network of microdomains which are not photomicroscopically observable when hydrated at 400×

magnification or less; and

(b) a proximal layer of enzyme reactive with said analyte.

2. A method of monitoring glucose levels, comprising:

(a) providing (i) a host, and (ii) an implantable device according to claim 1; and

(b) implanting said device in said host.

3. A method for preparing an implantable membrane comprising the steps of:

(a) forming a composition comprising a dispersion of a second polymer within a matrix of a first polymer, said dispersion forming a network of microdomains which are not photomicroscopically observable when hydrated at 400×

magnification or less;

(b) maintaining said composition at a temperature sufficient to maintain said first polymer and said second polymer substantially soluble;

(c) applying said composition at said temperature to a substrate to form a film thereon; and

(d) permitting said resultant film to dry to form said membrane.