Enhancing sensitivity and specificity in rare cell capture microdevices with dielectrophoresis

Area of Science:

• Biomedical Engineering
• Cell Biology
• Microfluidics

Background:

• Rare cell isolation, like circulating tumor cells (CTCs), is crucial for disease understanding and treatment.
• High-purity isolation techniques are needed to reduce costs and improve genetic analysis of single cells.
• Previous research combined dielectrophoresis (DEP) with immunocapture for differential cell isolation.

Purpose of the Study:

• To develop numerical simulations for optimizing microfluidic obstacle array geometries.
• To maximize the capture of target rare cells (e.g., cancer cells) using DEP-immunocapture.
• To minimize the capture of contaminating cells (e.g., leukocytes) in microfluidic devices.

Main Methods:

• Numerical simulations of microfluidic obstacle array geometries.
• Investigating electrode placement and fluid flow dynamics.
• Analyzing dielectrophoretic (DEP) forces and cell responses (positive DEP - pDEP, negative DEP - nDEP).

Main Results:

• Optimized electrode configurations maximize electric field strength at obstacle edges.
• pDEP cells are attracted to low-shear, high-residence time regions, increasing capture probability.
• nDEP cells are repelled from high-capture regions, minimizing contamination.

Conclusions:

• Simulations predict significant reduction in contaminating peripheral blood mononuclear cell capture (0.16 to 0.01).
• Simulations predict increased capture of pancreatic cancer cell lines (0.03-0.10 to 0.14-0.55).
• This work provides a foundation for experimental studies of hybrid DEP-immunocapture microdevices for rare cell isolation.