Dexamethasone Rejection Membranes for Accurate Glucose Sensing

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Solution Overview

Problem

Dexamethasone acetate interferes with the accuracy of amperometric glucose sensors, leading to decreased signal strength and instability, particularly in continuous glucose monitoring systems.

Innovation Solution

A dexamethasone rejection membrane (DRM) composed of poly(2-hydroxyethyl methacrylate) compositions is integrated into the sensor design to prevent dexamethasone penetration while maintaining glucose diffusivity, thereby enhancing sensor accuracy and stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Duration of action of stationary object

If dexamethasone acetate is used to extend sensor in vivo life-time, then sensor duration is improved, but sensor signal accuracy deteriorates due to interference with amperometric readings

Engineering Contradiction:
Improvesensor in vivo life-timeVSAvoidsensor signal accuracy
Core Design Contradiction:
Duration of action of stationary objectVSMeasurement precision

Solution Approach 1:

The sensor membrane is segmented into multiple functional layers: an outer dexamethasone rejection membrane (DRM) layer that blocks dexamethasone acetate penetration, and an inner glucose limiting membrane (GLM) layer that controls glucose diffusion. This segmentation allows the sensor to simultaneously achieve extended in vivo life-time through dexamethasone rejection while maintaining signal accuracy through controlled glucose diffusion, resolving the technical contradiction between durability and measurement precision

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The dexamethasone rejection membrane acts as an intermediary barrier between the dexamethasone acetate coating and the sensing elements. This intermediate DRM layer prevents dexamethasone from reaching and interfering with the amperometric sensor components, thereby protecting signal accuracy while allowing the dexamethasone coating to remain in place for its immunomodulatory function, thus resolving the contradiction between extended duration and measurement precision

Inventive Principle:
Principle #24Intermediary (Mediator)

2Object-affected harmful factors

If membrane thickness is increased to block dexamethasone, then dexamethasone rejection is improved, but glucose diffusivity deteriorates

Engineering Contradiction:
Improvedexamethasone rejectionVSAvoidglucose diffusivity
Core Design Contradiction:
Object-affected harmful factorsVSProductivity

Solution Approach 1:

The membrane exhibits local quality differentiation through its multi-layer structure: the outer DRM layer has high density and low permeability specifically tailored to reject dexamethasone molecules, while the inner GLM layer has optimized porosity and composition to facilitate glucose diffusion. This spatial differentiation of material properties allows the membrane to simultaneously achieve high dexamethasone rejection and maintained glucose diffusivity, resolving the technical contradiction between blocking harmful factors and maintaining productivity

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The membrane is constructed as a composite structure combining two distinct polymer materials with complementary properties: the DRM layer uses a polymer composition optimized for dexamethasone rejection, while the GLM layer uses a polymer composition optimized for glucose diffusion. This composite material approach enables the membrane to perform both functions simultaneously - blocking dexamethasone while allowing glucose transport - thereby resolving the contradiction between dexamethasone rejection and glucose diffusivity

Inventive Principle:
Principle #40Composite materials

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The DRM effectively reduces the impact of dexamethasone on sensor signals, improving accuracy and stability, and also minimizes interference from other substances like acetaminophen, ensuring reliable glucose monitoring.

Implementation Method 1

a dexamethasone rejection membrane (DRM), made from materials selected to prevent dexamethasone from penetrating into sensing elements of amperometric sensors

Methodology Applied
Scientific EffectPermeation: Permeation

Implementation Method 2

tailor the thickness and permeability of the DRM layer such that it does not interfere (or limit) the glucose diffusivity of the sensor while simultaneously preventing dexamethasone from impacting the glucose sensor signal

Methodology Applied
Scientific EffectDiffusion barrier: Diffusion Barrier

Implementation Method 3

an analyte sensing layer, wherein the analyte sensing layer includes an oxidoreductase

Methodology Applied
Scientific EffectEnzymatic reaction: Enzyme

Implementation Method 4

Amperometric analyte sensors (e.g., glucose sensors used in the management of diabetes) and methods and materials for making and using such sensors

Methodology Applied
Scientific EffectAmperometric detection:

Data Source

PatentEP4631428A1Sensor membranes for dexamethosone rejection
Publication Date: 2025.10.15 MEDTRONIC MINIMED INC
  • EP4631428A1 patent drawingFigure 1
  • EP4631428A1 patent drawingFigure 2A
  • EP4631428A1 patent drawingFigure 2B

AI summary

Embodiments of the invention provide amperometric analyte sensors having optimized elements such as dexamethasone rejection membranes as well as methods for making and using such sensors. The amperometric analyte sensor apparatus comprises: a base layer; a conductive layer disposed on the base layer and comprising a working electrode; a dexamethasone rejection membrane disposed over an electroactive surface of the working electrode, wherein the interference rejection membrane comprises a poly Hema composition and an analyte sensing layer. While embodiments of the innovation can be used in a variety of contexts, typical embodiments of the invention include glucose sensors used in the management of diabetes.