Understanding flow dynamics, viability and metastatic potency of cervical cancer (HeLa) cells through constricted microchannel

To understand the burgeoning challenges of metastasis, a microchannel of 35 mu m diameter, constricted to 7 mu m for a distance of 200 mu m in a total length of 3 mm, was designed and fabricated using a mask aligner made of polydimethylsiloxane (PDMS) to mimic in vivo capillaries. A thin glass cover-slide was mounted on top to monitor the motion of single or aggregated malignant HeLa cells (size 17-30 mu m) microscopically through the constricted microchannel at a constant flow rate of 30 mu l/h. Quantitative deconvolution of high-speed videographs of a single cell of 30 mu m revealed cellular deformation while passing through constriction, having elongation index, average transit velocity and entry time of 2.67, 18 mm/s and 5.1 ms, respectively. Morphological analysis of live and apoptotic cells by dual staining with Acridine Orange/Ethidium Bromide demonstrated retention of a significant viable cell population after exit through the constriction and a viability index of 50% was quantified by dye exclusion assay. The cumulative data for microfluidic parameters, morphology and relevant metastatic MMP2 gene expression efficiency measured by real-time polymerase chain reaction revealed retention of virulence potency that could possibly cause metastasis, would be beneficial in developing futuristic MEMS device for cancer theranostics.