Efficient elusion of viable adhesive cells from a microfluidic system by air foam

Abstract

We developed a new method for releasing viable cells from affinity-based microfluidic devices. The lumen of a microchannel with a U-shape and user-designed microstructures was coated with supported lipid bilayers functionalized by epithelial cell adhesion molecule antibodies to capture circulating epithelial cells of influx solution. After the capturing process, air foam was introduced into channels for releasing target cells and then carrying them to a small area of membrane. The results show that when the air foam is driven at linear velocity of 4.2 mm/s for more than 20 min or at linear velocity of 8.4 mm/s for more than 10 min, the cell releasing efficiency approaches 100%. This flow-induced shear stress is much less than the physiological level (15 dyn/cm 2 ), which is necessary to maintain the intactness of released cells. Combining the design of microstructures of the microfluidic system, the cell recovery on the membrane exceeds 90%. Importantly, we demonstrate that the cells released by air foam are viable and could be cultured in vitro. This novel method for releasing cells could power the microfluidic platform for isolating and identifying circulating tumor cells. V C 2014 AIP Publishing LLC.

Clinical Significance of Circulating Tumor Microemboli as a Prognostic Marker in Patients with Pancreatic Ductal Adenocarcinoma

“…Isolation and identification of CTCs were performed under a biomimetic supported lipid bilayer (SLB) surfacecoated microfluidic chip (CMx platform) conjugated with anti-epithelial cell adhesion molecule (EpCAM) as the CTC-capturing antibody (16,17 ). In brief, 2 mL of fresh blood sample collected from the patient into an EDTA Vacutainer Tube was transferred and traversed through the anti-EpCAM-coated SLB microfluidic chip under a 1.5 mL/h flow rate without additional processing.…”

Analytical validation of the CellMax platform for early detection of cancer by enumeration of rare circulating tumor cells

“…The standard operating procedures for microfluidic chip fabrication, micropattern etching, chip surface modification (lipid and EpCAM coating), and airfoam generation and application originate from published research studies at Academia Sinica. 18,40 Whole blood (2 mL mixed with 0.5 mL preservative) is loaded by syringe into the inlet port and pulled through a microfluidic channel by a syringe pump connected to the outlet port at a flow rate of 1.5 mL/h. The unbound cells are washed out of the chip with three washes of PBS buffer (0.2 mL at 3 mL/h).…”

Capturing Cancer: Emerging Microfluidic Technologies for the Capture and Characterization of Circulating Tumor Cells

“…However, some of these release techniques themselves may harm CTCs. For example, when introducing bubbles to generate tension forces, it is possible that the exerted force may go beyond the limit that CTCs can endure . Therefore, to obtain nondisrupted CTCs, release technologies should have a minimum influence on them.…”