Microparticle Separation Chip Pillar Spacing for CTC Capture
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Solution Overview
Problem
Current methods for detecting circulating tumor cells (CTCs) in blood face challenges such as low capture efficiency, clogging issues, and the inability to detect EpCAM-negative or slightly positive tumor cells, requiring complex and invasive procedures that are not suitable for bedside diagnostics.
Innovation Solution
A microparticle separation chip with pillars on a substrate, where the spacing between pillars allows passage of smaller cells but traps larger CTCs, enabling continuous processing without clogging and allowing for efficient separation of CTCs from whole blood without the use of anti-EpCAM antibodies.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If magnetic microparticles with anti-EpCAM antibodies are used for CTC concentration, then tumor cells can be concentrated, but EpCAM-negative or slightly positive tumor cells cannot be detected
Solution Approach 1:
The invention segments the CTC detection approach by separating the concentration function (achieved through size-based filtration) from the detection function (achieved through immunostaining). This allows the concentration step to capture all CTCs regardless of EpCAM expression, while the detection step can selectively identify specific subsets of CTCs.
Solution Approach 2:
The invention introduces a size-based filtration mechanism as an intermediary step between blood sampling and immunodetection. This intermediary concentration method does not depend on EpCAM expression, thereby enabling subsequent detection of EpCAM-negative cells that would be missed by direct immunomagnetic methods.
2Ease of manufacture
If polycarbonate membrane filters with 8 μm pore size are used for ISET, then the method is simple and inexpensive, but capture efficiency is only 50 to 60% due to low pore density and overlapping pores
Solution Approach 1:
The invention employs a porous structure with specifically engineered pore dimensions and distribution. The porous layer is configured with pore sizes and densities that optimize both CTC capture efficiency and throughput, overcoming the limitations of conventional polycarbonate filters while maintaining structural simplicity.
Solution Approach 2:
The invention changes the critical parameters of the filtration structure, specifically the pore size, pore density, and layer thickness, to optimize CTC capture. By adjusting these parameters, the system achieves high capture efficiency while maintaining simplicity and cost-effectiveness.
3Measurement precision
If multiple handling operations (cell dyeing, washing, separation, dispensing) are performed for CTC detection, then comprehensive analysis can be achieved, but CTC loss increases
Solution Approach 1:
The invention merges multiple handling operations into an integrated microfluidic system where concentration, washing, and detection occur in a continuous flow process. This integration eliminates manual transfer steps between separate devices, thereby reducing CTC loss while maintaining comprehensive analysis capability.
Solution Approach 2:
The invention creates a multi-functional device that performs concentration, separation, washing, and detection within a single integrated system. This universal device eliminates the need for multiple separate handling operations, thereby reducing CTC loss while achieving comprehensive analysis.
4Measurement precision
If large-scale equipment is used for CTC concentration and detection, then accurate detection can be achieved, but bedside examinations in a short period become difficult
Solution Approach 1:
The invention transitions from large-scale macroscopic equipment to a microscale device, utilizing microfluidic principles to achieve the same analytical functions in a compact format. This dimensional change enables accurate CTC detection to be performed at the bedside within a short period.
Solution Approach 2:
The invention replaces complex mechanical handling systems with a streamlined microfluidic system that uses controlled fluid flow to achieve concentration, separation, and detection. This substitution simplifies the operational requirements and enables rapid bedside examination while maintaining detection accuracy.
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 chip enables high-precision, rapid separation of low-content CTCs from whole blood, facilitating bedside cancer diagnosis and reducing the cost of CTC examination by allowing continuous processing and avoiding device clogging.
Implementation Method 1
a microparticle separation chip with pillars on a substrate, where the spacing between pillars allows passage of smaller cells but traps larger CTCs
Data Source
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Figure 5(1)~6(3)
AI summary
Provided is a microparticle separation chip capable of continuously separating microparticles from a solution in a short period of time in which microparticles having different particle diameters are mixed, without the need to use antibodies or the like. Also provided are a microparticle separation system and method for microparticle separation using the chip. The microparticle separation chip comprises a substrate and at least three or more pillars, a single capture site for capturing to-be-captured microparticles being formed using the at least three or more pillars having one end provided on the substrate and the other end open above, the spacing Z between any mutually adjacent pillars that form the single capture site being Y < Z ≤ X, where X is the size of the to-be-captured microparticles, and Y is the size of the microparticles to be removed, and the at least three or more pillars that form a single capture site being arranged in a positional relationship in which to-be-captured microparticles captured in the capture site do not flow out from between any adjacent pillars.