Fluid Flow Dependency in Immunoselective Cell Capture via Liquid Biopsy.

Area of Science:

• Biomedical Engineering
• Cell Biology
• Cancer Diagnostics

Background:

• Liquid biopsy aims to detect rare disease-specific cells using immunoaffinity capture.
• Healthy cells expressing similar biomarkers can reduce diagnostic accuracy.
• EpCAM is a key biomarker targeted in many liquid biopsy applications.

Purpose of the Study:

• To investigate the impact of settling time and rinsing flow rate on EpCAM-based immunoaffinity capture efficiency.
• To differentiate between cancer cells and healthy cells expressing EpCAM.
• To optimize liquid biopsy protocols for improved diagnostic specificity.

Main Methods:

• Computational simulation of cell-surface adhesion forces and shear rates.
• Experimental validation using three cell types with varying EpCAM expression.
• Systematic variation of static incubation times and rinsing flow rates.

Main Results:

• Healthy adherent cells showed minimal adhesion to blocked surfaces.
• Healthy EpCAM-positive cells exhibited some binding, impacting specificity.
• A high rinsing flow rate (25 mL/min) after 40 min static incubation maximized the differential capture efficiency.

Conclusions:

• Optimizing rinsing flow rates is crucial for enhancing the specificity of EpCAM-based liquid biopsies.
• Higher flow rates can effectively reduce the capture of non-target healthy cells.
• This optimization strategy offers a viable method for more precise cancer cell detection in liquid biopsies.