Numerical simulation of cell squeezing through a micropore by the immersed boundary method

Area of Science:

• Biomedical Engineering
• Cell Biology
• Microfluidics

Background:

• Cell deformability is a critical biomarker for identifying circulating tumor cells (CTCs) in blood samples.
• Microfluidic devices with microscale pores are utilized for CTC separation, requiring precise control over pore size and applied pressure.

Purpose of the Study:

• To conduct a parametric study on cell squeezing through micropores of varying sizes and pressures.
• To investigate the influence of membrane compressibility modulus and nucleus stiffness on cell deformability and translocation time.
• To evaluate the applicability of the Laplace-Young equation in microfluidic designs for CTC detection.

Main Methods:

• Computational simulation of cell squeezing through microscale pores.
• Parametric analysis varying micropore diameter, applied pressure, membrane compressibility modulus, and nucleus stiffness.
• Comparison of simulation results (cell shape, translocation time) with experimental observations.

Main Results:

• Cell translocation time through micropores increases with cell membrane compressibility modulus and nucleus stiffness.
• Translocation time increases exponentially with decreasing micropore diameter or applied pressure.
• Simulation results for cell squeezing shape and translocation time show good agreement with experimental data.

Conclusions:

• Cell deformability, influenced by membrane and nucleus properties, significantly affects CTC detection in microfluidic devices.
• Micropore size and applied pressure are critical parameters that require careful optimization for effective CTC separation.
• The Laplace-Young equation may require adjustments in microfluidic design due to non-uniform stress distribution and membrane bending resistance.