Clinical isolation of breast cancer Circulating Tumor Cells with an inertial microfluidic chip with a trapezoidal cross-section

In recent years, various detection and isolation methods for breast cancer have emerged. However, the lack of simple, unbiased separation techniques limits clinical applications of Circulating Tumor Cells (CTCs). This study introduces an inertial microfluidic chip with a trapezoidal cross-section for rapid, simple separation of MCF-7 CTCs from patient blood using an optimized SLA 3D printing technique. Simulations and experiments showed that increasing the slant angle enhances Dean vortices, with 1.2 mL/min as the optimal flow rate. Spiking MCF-7 cells into Phosphate-Buffered Saline (PBS) yielded a recovery rate of 88 ± 3.5 % and a purity of 99.99 %. When spiked into 7.5 mL lysed blood, the recovery was 86 ± 2.9 % and purity 94 ± 2.3 %, with over 90 % of cells remaining viable. Clinically, the chip detected MCF-7 cells in 8 out of 10 breast cancer patients (80 %), with cell counts ranging from 2 to 21 cells/mL and purities between 89 ± 1.6 % and 92 ± 5.8 %. These results confirm the chip’s high sensitivity and viability preservation. This straightforward inertial microfluidic method offers a promising alternative to traditional affinity-based CTC separation, supporting fundamental research and aiding patient treatment strategies.