ABSTRACT
OBJECTIVE: We have developed a novel simple wedge-shaped microfluidic device for highly efficient isolation of circulating tumor cells (CTCs) from cancer patient blood samples. METHODS: We used wet chemical etching and thermal bonding technologies to fabricate the wedge-shaped microdevice and performed optimization assays to obtain optimal capture parameters. Cancer cells spiked samples were used to evaluate the capture performance. Clinical assays were performed to isolate and identify CTCs from whole blood samples of patients with liver, breast, lung, and gastric cancer. RESULTS: Outlet height of 5.5 µm and flow rate of 200 µL/min were chosen as the optimal CTC-capture conditions. This method exhibited excellent isolation performance (more than 85% capture efficiency) for four cancer cell lines (HepG2, SKBR3, A549, and BGC823). In clinical assay, the platform identified CTCs 5 in 6 liver (83.3%), 8 in 10 breast (80%), 5 in 8 lung (62.5%), 5 in 9 gastric (55.6%) cancer patients, and only 1 in 25 healthy blood samples (4%). CONCLUSION: Our wedge-shaped microfluidic device had several advantages, including relatively simple fabrication, high capture efficiency, simple sample processing steps, and easy observation. SIGNIFICANCE: This method had successfully demonstrated the clinical feasibility of CTC isolation and shown a great potential of clinical usefulness in monitoring tumor prognosis and guiding individualized treatment in the future.
Subject(s)
Cell Separation/instrumentation , Lab-On-A-Chip Devices , Microfluidic Analytical Techniques/instrumentation , Neoplastic Cells, Circulating , Cell Line, Tumor , Cell Separation/methods , Equipment Design , Humans , Microfluidic Analytical Techniques/methods , Neoplasms/diagnosis , Neoplasms/pathologyABSTRACT
Circulating tumor cells (CTCs) have been regarded as the major cause of metastasis, holding significant insights for tumor diagnosis and treatment. Although many efforts have been made to develop methods for CTC isolation and release in microfluidic system, it remains significant challenges to realize highly efficient isolation and gentle release of CTCs for further cellular and bio-molecular analyses. In this study, we demonstrate a novel method for CTC isolation and release using a simple wedge-shaped microfluidic chip embedding degradable znic oxide nanorods (ZnNRs) substrate. By integrating size-dependent filtration with degradable nanostructured substrate, the capture efficiencies over 87.5% were achieved for SKBR3, PC3, HepG2 and A549 cancer cells spiked in healthy blood sample with the flow rate of 100 µL min-1. By dissolving ZnNRs substrate with an extremely low concentration of phosphoric acid (12.5 mM), up to 85.6% of the captured SKBR3 cells were released after reverse injection with flow rate of 100 µL min-1 for 15 min, which exhibited around 73.6% cell viability within 1 h after release to around 93.9% after re-cultured for 3 days. It is conceivable that our microfluidic device has great potentials in carrying on cell-based biomedical studies and guiding individualized treatment in the future.