Dynamic trapping and high-throughput patterning of cells using pneumatic microstructures in an integrated microfluidic device

Abstract

Microfluidic trapping methods create significant opportunities to establish highly controlled cell positioning and arrangement for the microscale study of numerous cellular physiological and pathological activities. However, a simple, straightforward, dynamic, and high-throughput method for cell trapping is not yet well established. In the present paper, we report a direct active trapping method using an integrated microfluidic device with pneumatic microstructures (PμSs) for both operationally and quantitatively dynamic localization of cells, as well as for high-throughput cell patterning. We designed and fabricated U-shape PμS arrays to replace the conventional fixed microstructures for reversible trapping. Multidimensional dynamics and spatial consistency of the PμSs were optically characterized and quantitatively demonstrated. Furthermore, we performed a systematic trapping investigation of the PμSs actuated at a pressure range of 0 psi to 20 psi using three types of popularly applied mammalian cells, namely, human lung adenocarcinoma A549 cells, human hepatocellular liver carcinoma HepG2 cells, and human breast adenocarcinoma MCF-7 cells. The cells were quantitatively trapped and controlled by the U-shape PμSs in a programmatic and parallel manner, and could be opportunely released. The trapped cells with high viability were hydrodynamically protected by the real-time actuation of specifically designed umbrella-like PμSs. We demonstrate that PμSs can be applied as an active microfluidic component for large-scale cell patterning and manipulation, which could be useful in many cell-based tissue organization, immunosensor, and high-throughput imaging and screening.

Microvalve and liquid membrane double-controlled integrated microfluidics for observing the interaction of breast cancer cells

“…Cell viability assessment was performed using an AO/PI staining protocol (Liu et al 2012). After removing the culture medium and rinsing with PBS, the AO/PI (5 lg/mL in PBS) staining solution was allowed to flow (5 lL/min) into the chambers.…”

“…With the foregoing analysis, as well as our previous studies on biological microfluidics Liu et al 2012) and on-chip cell assays (Huang et al 2011;Liu et al 2010b), we describe an integrated microfluidic device coordinated by liquid membranes for the precisely controlled investigation of self-seeding dynamics (e.g., migration and invasion) between MDA231-LM2 and MDA-MB231 breast cancer cells. Compared to existing technologies mentioned above, the microfluidic device can be used to conduct cell-based biological exploration in a multi-manipulating manner.…”

On-chip assay of the effect of topographical microenvironment on cell growth and cell-cell interactions during wound healing

“…Finally, samples were dried by using the critical point method and then sputter-coated by a thin layer of gold. 39 …”

“…39 After removing the growth medium and washing with PBS, the AO/PI staining solution (10 lg/ ml each in PBS) was introduced into the cell culture region, and the staining process was performed for 10 min at room temperature. Then, PBS was introduced for 10 min as a final rinse.…”

“…The PDMS micropillar substrate was fabricated using soft lithography. [37][38][39] First, the patterns were designed using AutoCAD software. Generally, the micropillar substrate had three regions (3 mm wide, 9 mm long, and separated by 800 lm space) and each region consisted of an array of cylindrical pillars.…”