Multidimensional Electrokinetic Cell Separation in High Conductance Samples

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Solution Overview

Problem

Conventional AC electrokinetic techniques, particularly dielectrophoresis (DEP), face limitations in efficiently separating and identifying rare cells, biomarkers, and nanoparticles in high conductance biological samples due to issues like sample dilution requirements, electrochemistry effects, and low throughput, which complicates clinical diagnostics and drug delivery processes.

Innovation Solution

The development of novel sample preparation and diagnostic systems that combine multidimensional AC electrokinetic and DEP forces with DC electrophoretic and microelectrophoretic techniques, using robust electrodes and porous structures to create separate high and low field regions within devices, allowing for efficient separation and analysis of cells, biomarkers, and nanoparticles under high ionic strength conditions without dilution or perturbation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional DEP techniques are used for separation, then separation capability is achieved, but sample dilution is required which reduces throughput and increases processing time

Engineering Contradiction:
Improveseparation capabilityVSAvoidthroughput
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The device segments the electrode array into multiple independent sections that can be activated simultaneously, allowing parallel processing of multiple sample regions. This segmentation enables the system to handle undiluted samples with high cell concentrations without requiring sequential processing or dilution, thereby maintaining both separation precision and high throughput.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent transitions from conventional two-dimensional electrode arrays to a three-dimensional configuration with electrodes positioned above and below the sample chamber. This dimensional expansion creates multiple electric field zones that can process different sample regions simultaneously, eliminating the need for sample dilution while maintaining effective separation capability.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Measurement precision

If conventional DEP techniques are used, then separation is achieved, but electrochemistry effects occur which compromise sample integrity

Engineering Contradiction:
Improveseparation capabilityVSAvoidelectrochemistry effects
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent introduces a dielectric layer as an intermediary between the electrodes and the sample. This intermediate layer prevents direct electrochemical reactions between the electrodes and sample components, eliminating harmful electrochemistry effects while still allowing the electric field to pass through and enable effective DEP separation.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The dielectric layer is designed with porous structure that allows the electric field to penetrate effectively while physically preventing direct contact between electrodes and sample. The porous material maintains electrical insulation properties to prevent electrochemistry while permitting field-mediated separation of cells and particles.

Inventive Principle:
Principle #31Porous materials

3Measurement precision

If conventional DEP techniques are used, then separation capability is maintained, but processing time increases due to low throughput

Engineering Contradiction:
Improveseparation capabilityVSAvoidprocessing time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The electrode array is divided into multiple independently controllable sections that can be activated simultaneously. This segmentation allows parallel processing of multiple sample regions, reducing the total processing time while maintaining the separation precision of individual electrode pairs.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent enables continuous sample flow through the device with multiple electrode sections operating simultaneously. This continuous processing eliminates idle time between sample injections and allows uninterrupted separation, significantly reducing overall processing time while maintaining effective separation capability.

Inventive Principle:
Principle #20Continuity of useful action

4Measurement precision

If sample dilution is performed to enable DEP, then separation can proceed, but sample volume requirements increase and rare cell detection efficiency decreases

Engineering Contradiction:
Improveseparation capabilityVSAvoidsample volume
Core Design Contradiction:
Measurement precisionVSQuantity of substance

Solution Approach 1:

The device segments the processing into multiple parallel electrode sections, each handling a portion of the undiluted sample. This segmentation allows the system to process the entire sample volume simultaneously without requiring dilution, maintaining the concentration of rare cells and minimizing the total sample volume needed for effective separation.

Inventive Principle:
Principle #1Segmentation

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

Enables rapid and high-throughput separation and identification of rare cells, biomarkers, and nanoparticles in undiluted biological samples, reducing sample processing time and minimizing sample perturbation, while avoiding electrochemistry-related issues, thus enhancing the sensitivity and specificity of clinical diagnostics.

Implementation Method 1

dielectrophoresis (DEP), which is an induced motion of particles produced by the dielectric differences between the particles and media in an AC electric field

Methodology Applied
Scientific EffectDielectrophoresis: Electrostatic Induction

Implementation Method 2

AC electroosmosis, which is surface fluid flow due to the surface charge on an electrode

Methodology Applied
Scientific EffectAC electroosmosis: Electro-Osmosis

Implementation Method 3

electrothermal flow, which is bulk flow in solution due to thermal gradients produced by the electric fields

Methodology Applied
Scientific EffectElectrothermal flow: Joule Heating

Implementation Method 4

DC electrophoretic and microelectrophoretic techniques

Methodology Applied
Scientific EffectElectrophoresis: Electrophoresis

Data Source

PatentEP2260297B1Ex-vivo multi-dimensional system for the separation and isolation of cells, vesicles, nanoparticles and biomarkers
Publication Date: 2018.08.01 RGT UNIV OF CALIFORNIA
  • EP2260297B1 patent drawingFigure 1~2
  • EP2260297B1 patent drawingFigure 3
  • EP2260297B1 patent drawingFigure 4

AI summary

Devices and techniques are described that involve a combination of multidimensional electrokinetic, dielectrophoretic, electrophoretic and fluidic forces and effects for separating cells, nanovesicles, nanoparticulates and biomarkers (DNA, RNA, antibodies, proteins) in high conductance (ionic) strength biological samples and buffers. In disclosed embodiments, a combination of continuous and/or pulsed dielectrophoretic (DEP) forces, continuous and/or pulsed field DC electrophoretic forces, microelectrophoresis and controlled fluidics are utilized with arrays of electrodes. In particular, the use of chambered DEP devices and of a properly scaled relatively larger electrode array devices that combines fluid, electrophoretic and DEP forces enables both larger and/or clinically relevant volumes of blood, serum, plasma or other samples to be more directly, rapidly and efficiently analyzed. The invention enables the creation of "seamless" sample-to-answer diagnostic systems and devices. The devices and techniques described can also carry out the assisted self-assembly of molecules, polymers, nanocomponents and mesoscale entities into three dimensional higher order structures.