Magnetic Profiling Device for Circulating Tumor Cell Capture
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Solution Overview
Problem
Current methods are inadequate for distinguishing between circulating tumor cells (CTCs) with high versus low metastatic potential due to their rarity and heterogeneity in blood samples, and existing techniques struggle to analyze the phenotypic properties of CTCs directly from unprocessed blood.
Innovation Solution
A device with a flow chamber and flow rate-reducing structures equipped with localized magnetic attractive forces, allowing for the capture and profiling of CTCs based on their magnetic susceptibility, enabling the separation and analysis of CTCs with high sensitivity and resolution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional flow cytometry or molecular analysis is used to profile CTCs, then measurement precision can be achieved, but the rarity and heterogeneity of CTCs in unprocessed blood samples makes direct analysis impossible
Solution Approach 1:
The flow chamber is divided into multiple capture zones with different magnetic field strengths, allowing sequential capture and profiling of CTC subsets based on their magnetic susceptibility. This segmentation enables precise phenotypic analysis of rare cells without requiring high concentrations in the sample.
Solution Approach 2:
Magnetic nanoparticles serve as intermediaries that attach to CTC surfaces and enhance their magnetic susceptibility. This intermediary allows detection and capture of rare CTCs in unprocessed blood samples, overcoming the limitation of their low concentration and heterogeneity.
2Productivity
If magnetic field strength is increased to capture more CTCs, then capture efficiency improves, but the ability to distinguish between different CTC subpopulations with varying magnetic susceptibility decreases
Solution Approach 1:
The magnetic field is segmented into multiple zones with progressively stronger field strengths along the flow path. This allows CTCs with different magnetic susceptibilities to be captured in different zones, maintaining both high capture efficiency and precise phenotypic resolution of subpopulations.
Solution Approach 2:
Different regions of the flow chamber are assigned different magnetic field strengths tailored to capture specific CTC subsets. This local differentiation enables simultaneous capture of diverse CTC types while maintaining the ability to distinguish their phenotypic properties through spatial separation.
3Measurement precision
If flow rate is reduced to increase capture time, then capture sensitivity improves, but the device complexity increases due to additional flow control structures
Solution Approach 1:
The flow chamber is segmented into multiple zones with progressively narrower cross-sections, creating natural flow rate reduction without complex external control systems. This segmentation achieves high capture sensitivity while keeping the device structure relatively simple and integrated.
Solution Approach 2:
Instead of controlling flow rate through complex temporal or external mechanisms, the design uses spatial dimensionality by narrowing the channel cross-section along the flow path. This dimensional approach to flow control simplifies the device while maintaining capture sensitivity through increased residence time in each zone.
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 device effectively captures and profiles CTCs with high sensitivity and single-cell resolution, facilitating the study of their phenotypic changes and metastatic potential, even in low numbers within unprocessed blood samples, and provides profiles comparable to conventional flow cytometry.
Implementation Method 1
each flow rate-reducing structure being provided with a localized magnetic attractive force (e.g., provided with a circular nickel micro-magnet that induces the localized magnetic attractive force), the magnetic attractive force defining a capture zone in the vicinity of the flow rate-reducing structure
Implementation Method 2
different target particles having different magnetic susceptibility are captured in different capture zones
Implementation Method 3
the magnetic attractive force in the capture zone, is sufficiently high to overcome drag force on a given subset of the target particles to promote capture
Data Source
AI summary
Methods and devices for magnetic profiling of target particles in a flow. There are a plurality of flow rate-reducing structures in a flow chamber. Each flow rate-reducing structure is provided with a localized magnetic attractive force, the magnetic attractive force defining a capture zone in the vicinity of the flow rate-reducing structure. The size of capture zones may be variable for different locations within the device. The magnetic attractive force, in the capture zone, is sufficiently high to overcome the drag force on a given subset of the target particles to promote capture of any particles belonging to the subset of the target particles in the capture zone. Different target particles having different magnetic susceptibility are captured in different capture zones.