Rapid Capture of Rare Cancer Cells Using a High-Performance Microfluidic Chip

Rare circulating tumor cells (CTCs) are cancer cells that detached from either a primary tumor or metastatic sites. CTCs circulate into bloodstream and become the origin of metastasis, the spread of cancer to distant organs, which is the primary cause of cancer-induced death. This paper describes our development of a microfluidic chip with unique micropillar geometry for rapid capture of CTCs from whole blood. The microscope-slide-sized microchip contains tens of thousands of isotropically-etched elliptical micropillars, which enhanced the interactions between cells and chip surfaces. The microchip was coated with DNA aptamer, an antibody-like molecule which can specifically bind with their target cells. With optimized channel geometry and flow rate, the microchip yielded a capture efficiency of >95% and a purity of >81% when capturing leukemia cells from a cell mixture. Then, the device was applied to capture colorectal tumor cells from whole blood; as few as 10 tumor cells can be efficiently isolated from 1 mL blood in 28 min. We envision that this high-performance microchip is promising for the detection, enrichment and isolation of rare CTCs, and will open up new opportunities for cancer diagnosis and monitoring cancer treatment.