All-in-One Centrifugal Microfluidic Device for Size-Selective Circulating Tumor Cell Isolation with High Purity

Abstract

Circulating tumor cells (CTCs) have gained increasing attention owing to their roles in cancer recurrence and progression. Due to the rarity of CTCs in the bloodstream, an enrichment process is essential for effective target cell characterization. However, in a typical pressure-driven microfluidic system, the enrichment process generally requires complicated equipment and long processing times. Furthermore, the commonly used immunoaffinity-based positive selection method is limited, as its recovery rate relies on EpCAM expression of target CTCs, which shows heterogeneity among cell types. Here, we propose a centrifugal-force-based size-selective CTC isolation platform that can isolate and enumerate CTCs from whole blood within 30 s with high purity. The device was validated using the MCF-7 breast cancer cell line spiked in phosphate-buffered saline and whole blood, and an average capture efficiency of 61% was achieved, which is typical for size-based filtration. The capture efficiency for whole blood samples varied from 44% to 84% under various flow conditions and dilution factors. Under the optimized operating conditions, a few hundred white blood cells per 1 mL of whole blood were captured, representing a 20-fold decrease compared to those obtained using a commercialized size-based CTC isolation device. In clinical validation, normalized CTC counts varied from 10 to 60 per 7.5 mL of blood from gastric and lung cancer patients, yielding a detection rate of 50% and 38%, respectively. Overall, our CTC isolation device enables rapid and label-free isolation of CTCs with high purity, which should greatly improve downstream molecular analyses of captured CTCs.

Highly-sensitive capture of circulating tumor cells using micro-ellipse filters

“…Slanted spiral microfluidics could ultra-fast, label-free isolate CTCs 26 utilizing Vortex technology combining use of micro-scale vortices and inertial focusing 8 . A centrifugal-force-based size-selective CTC microfluidic device 27 , a CTC Cluster-Chip 28 , a cascaded spiral microfluidic device 29 , a microfluidic rachet 30 and a multi-obstacle architecture (MOA) filter 31 are recently described. Dedicated efforts have been made to overcome size-overlapped between CTCs (15 µm–25 µm) and White blood cells (WBCs) (9 µm–16 µm) 32 .…”

Circulating tumor cells detected by lab-on-a-disc: Role in early diagnosis of gastric cancer

“…To identify CTCs directly in blood, we recently developed a centrifugal microfluidic system based on a new fluid-assisted separation technique (FAST), in which size-based separation occurs within a centrifugal microfluidic device at a liquid-liquid interface, instead of the conventional liquid-gas interface [10, 11]. In a previous study, we showed that FAST enabled the highly sensitive, selective, rapid, and label-free isolation of CTCs from whole blood without prior sample treatment [10].…”

Analysis of circulating tumor cells from lung cancer patients with multiple biomarkers using high-performance size-based microfluidic chip

“…Initially, tumor cells disseminated from solid tumors undergo epithelial-to-mesenchymal transition (EMT) for achieving their migratory and invasive properties [2]. Circulating tumor cells(CTCs) are tumor cells turning into blood circulation system, which are critical for metastasis [3].…”