Sheathless High-Throughput Circulating Tumor Cell Separation Using Viscoelastic non-Newtonian Fluid

Area of Science:

• Biomedical Engineering
• Microfluidics
• Cell Separation Technology

Background:

• Circulating tumor cells (CTCs) are crucial biomarkers in cancer diagnostics and prognostics.
• Existing microfluidic methods for CTC separation often rely on immunoaffinity or size differences.
• There is a need for high-throughput, label-free CTC separation techniques.

Purpose of the Study:

• To develop and validate a sheathless, high-throughput microfluidic device for CTC separation.
• To utilize viscoelastic fluid properties for efficient separation of CTCs from white blood cells (WBCs).
• To determine optimal fluid viscoelasticity and flow rates for effective CTC isolation.

Main Methods:

• Characterization of particle flow dynamics (6, 13, 27 μm) in viscoelastic fluids (hyaluronic acid solutions) at various concentrations and flow rates.
• Implementation of a sheathless microfluidic system utilizing viscoelastic fluid properties.
• Validation of the separation device using MCF-7 cells as CTC models and peripheral blood mononuclear cells (PBMCs) as WBC models.

Main Results:

• Optimal separation was achieved using a 0.2% hyaluronic acid solution at a flow rate of 500 μL/min.
• The microfluidic device demonstrated a high separation efficiency of 94.8% for MCF-7 cells from WBCs.
• A small percentage of MCF-7 cells (~5.2%) were detected at the center outlet due to size overlap with WBCs.

Conclusions:

• Viscoelastic fluid-based microfluidics offer a promising approach for sheathless, high-throughput CTC separation.
• This method provides a label-free and efficient way to isolate CTCs, valuable for cancer research and clinical applications.
• Further optimization may improve separation efficiency, particularly for CTCs with size overlap with WBCs.