Dynamic Halbach array magnet integrated microfluidic system for the continuous-flow separation of rare tumor cells

Area of Science:

• Biomedical Engineering
• Microfluidics
• Cancer Diagnostics

Background:

• Circulating tumor cells (CTCs) are crucial biomarkers for liquid biopsy and personalized medicine.
• Existing CTC isolation methods face challenges due to CTC rarity and heterogeneity.
• Need for efficient and sensitive methods for isolating intact CTCs from whole blood.

Purpose of the Study:

• To develop and validate a novel microfluidic system for the negative isolation of CTCs.
• To enable continuous-flow separation of CTCs without sample volume limitations.
• To provide intact CTCs for downstream cellular and molecular analyses.

Main Methods:

• Development of a dHAMI (dynamic Halbach array magnet microfluidic system).
• Utilized magnetic beads to label and capture non-target white blood cells (WBCs).
• Employed a continuously moving Halbach array magnet to generate a dynamic magnetic field for WBC exclusion and CTC elution.
• Optimized flow rate and immunomagnetic bead concentration for efficient separation.

Main Results:

• The dHAMI microfluidic system achieved an average CTC capture rate of 91.6% for spiked cells (50-1000 cells/mL).
• Successful isolation of CTCs was completed within 40 minutes.
• CTCs were detected in 100% (10/10) of patient blood samples.
• Demonstrated effective isolation of intact and heterogeneous CTCs.

Conclusions:

• The dHAMI microfluidic system provides an effective platform for isolating intact CTCs.
• The system shows high capture efficiency and robustness for rare cell separation.
• Potential applications include personalized medicine, cancer diagnostics, and separation of other rare cells.