Enzymatic HbA1c Detection via Protease Digestion

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Current Point-of-Care devices for measuring HbA1c suffer from false high results due to hemoglobin variances (HbS and HbC), leading to inaccurate long-term blood glucose level monitoring in diabetes patients.

Innovation Solution

An electrochemical system using enzymatic methods, specifically employing proteases like Toyobo's Neutral Proteinase and Fructosyl Amino acid oxidase, to break down hemoglobin and measure HbA1c concentrations, bypassing the peroxide generation step and utilizing interdigitated gold electrodes for signal amplification, thereby eliminating variance-related errors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If immunochemistry (antigen-antibody) based system is used for HbA1c measurement, then the measurement can be performed at Point-of-Care, but false high results occur due to hemoglobin variances (HbS and HbC)

Engineering Contradiction:

ImprovePoint-of-Care testing capabilityVSAvoidHbA1c measurement accuracy

Core Design Contradiction:

Ease of operationVSMeasurement precision

Solution Approach 1:

The patent replaces the immunochemistry-based detection system with an enzymatic detection system. Specifically, it uses fructosyl amino acid oxidase enzyme to catalyze the oxidation of fructosyl-valylhistidine, generating electrons that are detected electrochemically. This substitution of detection mechanism eliminates the interference from hemoglobin variances while maintaining Point-of-Care applicability.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the detection parameter from antibody binding (immunochemistry) to enzymatic reaction rate (electrochemical current). By measuring the current generated from the enzymatic oxidation reaction, the system achieves accurate HbA1c quantification independent of hemoglobin variants, while keeping the test format suitable for Point-of-Care use.

Inventive Principle:

Principle #35Parameter changes

2Measurement precision

If enzymatic method with proteases is used to break down hemoglobin, then HbA1c measurement accuracy is improved, but the system complexity increases

Engineering Contradiction:

ImproveHbA1c measurement accuracyVSAvoidsystem complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent incorporates a protease enzyme (Toyobo's Neutral Proteinase) that pre-breaks down hemoglobin proteins into peptides before the HbA1c-specific enzymatic detection. This preliminary digestion step simplifies the overall system by eliminating the need for complex protein separation procedures, while still achieving high measurement accuracy through the subsequent enzymatic oxidation reaction.

Inventive Principle:

Principle #10Preliminary action

3Adaptability or versatility

If multiple electrochemical test strips are used for multi-analyte testing, then versatility is improved, but device complexity increases

Engineering Contradiction:

Improvemulti-analyte testing capabilityVSAvoidnumber of test strips

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent designs an electrochemical test strip system where a single strip can perform multiple functions by incorporating different enzymes and reagents. The strip includes a glucose oxidase zone for glucose measurement, a fructosyl amino acid oxidase zone for HbA1c measurement, and other analyte-specific zones. This multi-functional design allows one universal test strip to replace multiple single-purpose strips, reducing overall device complexity while maintaining versatility.

Inventive Principle:

Principle #6Universality (Multi-functionality)

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

This approach provides more accurate HbA1c measurements, reducing false positives and enabling easier NGSP certification, with improved accuracy and versatility for multi-analyte testing, particularly in populations with hemoglobin variances.

Implementation Method 1

a stripe with a coating of Fructosyl Amino acid oxidase (FPO-301) enzyme that acts on Fructosyl-L-Valylhistidine as substrate

Methodology Applied

Scientific EffectEnzyme catalysis: Enzyme

Implementation Method 2

Fructosyl Amino oxidase directly transfers the electron to the mediator thus by-passing the peroxide generation step

Methodology Applied

Scientific EffectElectron transfer: Oxidation

Implementation Method 3

released hemoglobin reacts with the potassium ferricyanide solution to form methemoglobin

Methodology Applied

Scientific EffectOxidation: Oxidation

Implementation Method 4

utilizing interdigitated gold electrodes for signal amplification

Methodology Applied

Scientific EffectElectrochemical detection: Conduction (electrical)

Data Source

PatentUS11703513B2Systems and methods for enzymatic A1C detection and quantification

Publication Date: 2023.07.18 POLYMER TECHNOLOGY SYSTEMS INC

AI summary

A system for determining a concentration of hemoglobin A1C includes a first electrochemical test strip, the first electrochemical test strip providing for an HbA1C concentration; and a second electrochemical test strip, the second electrochemical test strip providing for the total amount of hemoglobin.