Protamine-Coated Surfaces for Extracellular Vesicle Capture
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Solution Overview
Problem
Current methods for isolating extracellular vesicles (EVs) from biological fluids face challenges such as complexity, inefficiency, damage to vesicles during purification, and the need for large sample sizes, with existing techniques like ultracentrifugation and size exclusion chromatography being difficult to standardize and prone to contamination.
Innovation Solution
A method involving a solid surface coated with protamine hydrochloride, a polycationic substance, is used to capture and quantify EVs without additional reagents or processing steps, utilizing a microtiter plate, magnetic beads, or other solid surfaces to bind EVs based on their negative charge, allowing for efficient detection and quantification.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If differential ultracentrifugation or density gradient ultracentrifugation is used for EV purification, then EV isolation efficiency is improved, but EV integrity is damaged and membrane debris is observed
Solution Approach 1:
The patent replaces the mechanical ultracentrifugation system with a chemical adsorption system using protamine-coated surfaces. EVs are captured through electrostatic interactions between the positively charged protamine and negatively charged EV surfaces, eliminating mechanical shear stress while maintaining high capture efficiency
Solution Approach 2:
The patent changes the purification mechanism from mechanical force-based (ultracentrifugation) to electrostatic interaction-based (protamine adsorption). This parameter change allows EV isolation without the damaging high-speed rotation, preserving EV integrity while achieving efficient purification
2Reliability
If size exclusion chromatography is used for EV purification, then EV integrity is maintained, but EV recovery efficiency is reduced
Solution Approach 1:
The patent replaces the mechanical chromatography system with a chemical adsorption system. Instead of relying on size-based physical separation through columns, EVs are captured through electrostatic adsorption to protamine-coated surfaces, achieving both high integrity and high recovery efficiency
Solution Approach 2:
The patent uses a composite approach by coating solid surfaces with protamine, creating a material that combines the structural properties of the solid support with the electrostatic binding properties of protamine. This composite material enables efficient EV capture while maintaining integrity
3Quantity of substance
If polymeric precipitation methods are used for EV isolation, then EV concentration from small samples is improved, but EV contamination increases
Solution Approach 1:
The patent applies local quality by using protamine coating specifically on the solid surface where EV capture is needed. This localized application ensures that only EVs are captured through electrostatic interactions, while other contaminants remain in solution, achieving both concentration and purity
4Productivity
If conventional EV purification methods are used, then EV isolation is achieved, but the methods are complex and difficult to standardize
Solution Approach 1:
The patent extracts the essential function of EV purification from complex multi-step procedures and concentrates it into a single adsorption step using protamine-coated surfaces. This simplification maintains isolation capability while eliminating complexity and standardization difficulties
Solution Approach 2:
The patent creates a universal platform using protamine-coated surfaces that can capture EVs from various biological fluids through a single standardized protocol. This multi-functional approach works across different sample types without requiring method optimization, reducing complexity
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 simplifies the detection and quantification of EVs from small samples, maintaining their integrity and avoiding the need for expensive equipment, while providing a more efficient and effective method for diagnostic applications.
Implementation Method 1
A method involving a solid surface coated with protamine hydrochloride, a polycationic substance, is used to capture and quantify EVs without additional reagents or processing steps, utilizing a microtiter plate, magnetic beads, or other solid surfaces to bind EVs based on their negative charge
Data Source
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AI summary
The invention relates to a method and a kit for capturing on a solid surface the extracellular vesicles (EVs) which are present in a biological fluid sample. The solid surface is coated with a polycationic substance, preferably a protamine salt such as protamine hydrochloride. The method and kit of the invention is useful for the detection and/or quantification of the extracellular vesicles (EVs) which are present in a biological fluid sample, particularly in a diagnostic context.