Microfluidic CTC Capture via Rotational Flow and Selectin Binding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for detecting circulating tumor cells (CTCs) in blood are invasive, time-consuming, and lack sensitivity and specificity, making them unsuitable for routine clinical practice due to the rarity of CTCs in the bloodstream compared to normal blood cells.
Innovation Solution
A microfluidic device with a cell capture surface immobilized with selectins or their fragments and capturing agents like antibodies or peptides, which induces rotational flow to enhance the binding and capture of CTCs, utilizing shear stress and specific binding agents to isolate CTCs from blood samples.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If conventional methods (Ficoll-based assays, immunomagnetic enrichment) are used to detect DTCs, then enrichment is relatively easy, but the process is invasive, time-consuming, and painful for patients
Solution Approach 1:
The patent replaces mechanical enrichment methods (Ficoll centrifugation, immunomagnetic separation) with a microfluidic system that uses controlled fluid flow and shear stress to induce cell rolling and capture. The microfluidic device uses hydrodynamic forces and surface-bound selectins to selectively capture CTCs, eliminating the need for invasive bone marrow aspiration and complex manual enrichment procedures.
Solution Approach 2:
The patent introduces selectins (E-selectin, P-selectin, L-selectin) as intermediary molecules bound to the microfluidic channel surface. These selectins act as mediators that interact with CTC surface proteins to induce cell rolling and facilitate capture, providing a specific and gentle mechanism that avoids the invasiveness of conventional enrichment methods.
2Ease of operation
If CTCs are detected in peripheral blood, then minimal invasiveness and easy samplings are achieved, but the rarity of CTCs (1 in 10^6-10^9 normal blood cells) presents tremendous challenge for efficient detection
Solution Approach 1:
The patent changes the detection parameters by applying controlled shear stress (0.05-10 dyn/cm²) to the blood sample in the microfluidic device. This shear stress parameter induces CTCs to roll and adhere to the selectin-coated surface, while normal blood cells continue flowing. The controlled hydrodynamic conditions enable sensitive detection of rare CTCs without requiring invasive procedures.
Solution Approach 2:
The patent applies local quality by coating only the microfluidic channel surface with selectins and capturing agents, creating a localized capture zone. This localized functionalization allows specific interaction with CTCs as they pass through the channel, while the rest of the system remains simple and non-invasive for blood sampling.
3Productivity
If rotational flow is induced in the microfluidic device, then CTC binding and capture efficiency is enhanced, but device complexity increases
Solution Approach 1:
The patent uses curved or rounded geometric features in the microfluidic channel design to induce rotational flow. The curved channel walls and rounded corners create vortex flows that enhance CTC interaction with the selectin-coated surface, improving capture efficiency without requiring complex mechanical flow induction devices.
Solution Approach 2:
The patent employs hydraulic principles by using pressure-driven flow through carefully designed channel geometries to generate rotational flow patterns. The microfluidic device uses hydrodynamic forces and pressure gradients to induce cell rolling and enhance capture, avoiding the need for complex mechanical mixing or flow induction mechanisms.
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 achieves high-throughput separation of CTCs with enhanced sensitivity and specificity, improving the efficiency of CTC capture and isolation, facilitating more effective diagnosis and prognosis of cancer.
Implementation Method 1
the device inducing a rotational flow with the sample
Implementation Method 2
applying a shear stress between 0.05 dyn/cm2 and 10 dyn/cm2 on the sample introduced into the device
Implementation Method 3
The metastasis mechanism is known to be initiated by cell rolling the naturally occurring process utilized to recruit leukocytes to sites of inflammation
Implementation Method 4
a CTC to bind to a cell rolling-inducing agent and a capturing agent
Implementation Method 5
the capturing agent specifically binds a moiety on a CTC cell surface
Implementation Method 6
the cells firmly attach to the endothelial cells
Data Source
AI summary
A method of capturing a Circulating Tumor Cell (CTC) from a sample includes introducing a sample into a microfluidic device having a cell capture surface and a flow modification surface under conditions that allow a CTC to bind to a cell rolling-inducing agent and a capturing agent disposed on the cell capture surface. The flow modification surface induces a rotational flow within the sample as it flows through the microfluidic device.