Quasi-soft catcher for intact rare cell capture
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Solution Overview
Problem
Current methods for capturing rare cells such as circulating tumor cells (CTC) and fetal nucleated red blood cells (fNRBC) are inefficient due to cell damage and low capture rates, with centrifugation losing target cells, immunomagnetic bead technology damaging cells, and microchannel technology causing cell clumping and low capture rates.
Innovation Solution
A quasi-soft catcher with protruding structures that have a weaker inner portion connected to a stronger outer portion, arranged on a board surface with an interspace region, designed to capture and separate target biological particles without damaging them, using a mechanical method to cut the inner portions and release the cells.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If immunomagnetic bead technology is used to capture rare cells, then capture capability is improved, but cell integrity deteriorates due to collisions and mechanical damage
Solution Approach 1:
The invention uses a flexible PDMS membrane with micro-protrusions that can deform elastically to capture cells. The protrusions act as soft, compliant structures that conform to cell shapes without causing mechanical damage, resolving the contradiction between capture capability and cell integrity.
Solution Approach 2:
The invention changes the mechanical parameters of the capture structure by using elastomeric PDMS material with specific Young's modulus values (0.1-10 MPa), making the structure soft and compliant. This parameter change allows the protrusions to gently interact with cells, improving both capture efficiency and cell preservation.
2Extent of automation
If microchannel technology is used for cell separation, then automated processing is improved, but cell capture rate deteriorates due to shear forces causing cell clumping
Solution Approach 1:
The invention segments the continuous microchannel flow into discrete capture zones defined by arrays of micro-protrusions. Each protrusion acts as an independent capture unit, allowing cells to be captured individually without the shear forces that cause clumping in continuous flow channels.
Solution Approach 2:
The invention introduces dynamic control of fluid flow through the chamber, allowing the flow rate and direction to be adjusted. This dynamic control enables gentle cell delivery to the protrusions without excessive shear forces, improving capture rate while maintaining cell integrity.
3Productivity
If centrifugation method is used to purify rare cells, then separation efficiency is improved, but target cell loss increases due to multiple liquid transfers
Solution Approach 1:
The invention merges the separation and capture functions into a single integrated chamber where rare cells are directly captured on the PDMS membrane from the blood sample. This eliminates the need for multiple liquid transfer steps between different centrifugation tubes and processing vessels, reducing target cell loss while maintaining separation efficiency.
Data Source
AI summary
A quasi-soft catcher, a quasi-soft capture device, and a method for using the same are provided. The quasi-soft catcher includes a base and a plurality of protruding structures for capturing at least one target biological particle from a specimen. The protruding structures are regularly arranged on a board surface of the base. Each of the protruding structures includes an outer portion configured to touch the at least one target biological particle and an inner portion that is connected between the board surface and the outer portion, and a structural strength of the inner portion is less than that of the outer portion. The board surface has an interspace region arranged outside of the protruding portions, and the interspace region occupies 20-80% of the board surface.