Microfluidic biosensing of viscoelastic properties of normal and cancerous human breast cells

Biomechanical properties have been revealed as potential biomarkers for distinguishing cancer cells from normal cells. In this work, we report a novel technique using a confining microchannel embedded with microelectrodes for biomechanical phenotyping for floating human cells, including one normal breast cell line (MCF-10A) and two breast cancer cell lines (MCF-7 and MDA-MB-231). The floating cells move under a defined pressure profile along the microchannel, in which the cells deform dynamically under compression by the channel sidewalls. We adopt Hertz and Tatara models to convert the deformed cell shapes to cell diameters and transient stress-strain ratios. By further considering the cell viscoelasticity as a Standard Linear Solid (SLS) model, we compute for whole-cell viscosity, and instantaneous and relaxed moduli. Our results show that the selected cell types have significant different viscoelastic properties. Applications of the electrode-embedded confining microchannel can achieve high-throughput, continuous-flow deep phenotyping of rare cells by functionalizing channel side walls with antibodies for both biomechanical and biochemical biomarkers for more comprehensive and promising cell characterization.