Biointerface layer for analyte sensors

Abstract

Disclosed are devices for determining an analyte concentration (e.g., glucose). The devices comprise 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 biointerface layer which interfaces with a biological fluid containing the analyte to be measured. The biointerface layer comprises a biointerface polymer, wherein the biointerface polymer comprises polyurethane and / or polyurea segments and one or more zwitterionic repeating units. The biointerface layer increases sensor longevity and decrease sensor inaccuracy by inhibiting accumulation of cells, proteins, and other biological species on the outermost layers of the sensor.

Description

INCORPORATION BY REFERENCE TO RELATED APPLICATIONS[0001]Any and all priority claims identified in the Application Data Sheet, or any correction thereto, are hereby incorporated by reference under 37 CFR 1.57. This application claims the benefit of U.S. Provisional Application No. 62 / 273,155, filed Dec. 30, 2015; U.S. Provisional Application No. 62 / 273,142, filed Dec. 30, 2015; and U.S. Provisional Application No. 62 / 273,219, filed Dec. 30, 2015. Each of the aforementioned applications is incorporated by reference herein in its entirety, and each is hereby expressly made a part of this specification.FIELD[0002]The subject matter disclosed herein relates to devices for measuring a biological analyte in a host and to components of such devices.BACKGROUND[0003]Electrochemical sensors are useful for determining the presence or concentration of a biological analyte, such as blood glucose. Such sensors are effective, for example, at monitoring glucose in diabetic patients and lactate durin...

AI Technical Summary

Benefits of technology

The invention introduces a layer that prevents the accumulation of cells, proteins, and other living organisms on the outermost layers of a sensor. This layer helps to increase the lifespan of the sensor and reduce inaccuracy in vivo. By reducing inflammation and other biological responses, the accumulation of biological species on the sensor is minimized, resulting in more accurate readings.

Problems solved by technology

A challenge associated with long-term use of continuous sensors and other medical devices is biomaterial-associated inflammation, which is the inflammation caused by implantation of foreign materials into the body.

The formation of a barrier cell layer around the implanted device can result in impaired tissue integration.

In the case of a continuous sensor, biomaterial-associated inflammation can impair analyte transport from tissues to the sensor surface, whether by creating a diffusion barrier or active consumption of analytes.

The FBGC response to implantable materials results in fibrous capsule formation that impedes sensor function through the modulation of glucose diffusion through dense fibrotic “scar-tissue” layers.

These interferents can cause sensor inaccuracy due to the constant change in transport properties at the sensor / tissue interface.

Aside from diffusion limitations, there exists an active cellular component of the biomaterial-associated inflammatory cascade, involving inflammatory and wound healing cells; these cells that can be activated by implanted materials can actively consume glucose and produce H2O2, which can also lead to sensor inaccuracy.

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