Implanted Sensor Drug-Eluting Matrix for Immune Protection

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Solution Overview

Problem

Implanted sensors in living animals face degradation due to the immune system's response, particularly from reactive oxygen species like hydrogen peroxide, which degrades analyte indicator molecules, reducing the sensor's effectiveness over time.

Innovation Solution

A sensor design incorporating a drug-eluting polymer matrix with therapeutic agents dispersed within, which covers the sensor housing and optionally the analyte indicator, to reduce deterioration by inhibiting neutrophil migration and oxidative degradation, and a membrane that prevents white blood cells from reaching the indicator while allowing analyte passage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a sensor is implanted in a living animal, then the sensor can measure analytes in vivo, but the immune system attacks the sensor and degrades the analyte indicator molecules

Engineering Contradiction:
Improvesensor effectivenessVSAvoidimmune system attack
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

A membrane is introduced as an intermediary layer between the immune system and the analyte indicator molecules. This membrane selectively blocks white blood cells and reactive oxygen species while permitting analyte molecules to pass through, thereby protecting the indicator from immune attack without interfering with analyte measurement

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The sensor is pre-coated with a drug-eluting polymer matrix containing therapeutic agents before implantation. This preliminary protective layer prevents neutrophil migration and oxidative degradation from the outset, countering the immune system's harmful effects before they can damage the analyte indicator

Inventive Principle:
Principle #9Preliminary anti-action

2Reliability

If a membrane is added to protect the analyte indicator from white blood cells, then indicator degradation is reduced, but the device complexity increases

Engineering Contradiction:
Improveindicator stabilityVSAvoidsensor structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The protective membrane and the drug-eluting polymer matrix are merged into a single integrated coating layer on the sensor housing. This combination provides both physical protection from white blood cells and chemical protection from oxidative degradation without requiring separate components, thereby reducing overall device complexity while maintaining dual protective functions

Inventive Principle:
Principle #5Merging (Combining)

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 solution significantly reduces analyte indicator degradation, enhancing the sensor's longevity and functionality by maintaining measurement accuracy over extended periods, as demonstrated by experimental results showing greater than 90% modulation compared to in vitro conditions after 30 days in an animal model.

Implementation Method 1

one or more therapeutic agents that reduce deterioration of the analyte indicator. The sensor includes at least one drug eluting polymer matrix, and the one or more therapeutic agents are dispersed within the drug eluting polymer matrix

Methodology Applied
Scientific EffectDrug elution:

Implementation Method 2

hydrogen peroxide may degrade the indicator molecules by oxidizing the boronate group, thus disabling the ability of the indicator molecule to bind glucose

Methodology Applied
Scientific EffectOxidative degradation: Oxidation

Implementation Method 3

a membrane covering at least a portion of the analyte indicator, and the one or more therapeutic agents are incorporated within the membrane

Methodology Applied
Scientific EffectSelective permeation: Semipermeable Membrane

Data Source

PatentEP3427661B1Drug elution for in vivo protection of bio-sensing analytes
Publication Date: 2020.05.13 SENSEONICS INC
  • EP3427661B1 patent drawingFigure 1
  • EP3427661B1 patent drawingFigure 2
  • EP3427661B1 patent drawingFigure 3

AI summary

A sensor (e.g., an optical sensor) that may be implanted within a living animal (e.g., a human) and may be used to measure an analyte (e.g., glucose or oxygen) in a medium (e.g., interstitial fluid, blood, or intraperitoneal fluid) within the animal. The sensor may include a sensor housing, an analyte indicator covering at least a portion of the sensor housing, and one or more therapeutic agents. The one or more therapeutic agents may be incorporated within the analyte indicator, a membrane covering at least a portion of the analyte indicator, and/or one or more drug eluting polymer matrices that cover at least a portion of the sensor housing and are applied to the sensor housing via dip coating or spray coating.