Characterization of viscoelastic properties of normal and cancerous human breast cells using a confining microchannel

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 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 the Hertz and Tatara model to convert deformed cell shapes to cell diameters and transient stress–strain ratios. By further considering cell viscoelasticity as a standard linear solid 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. We further implement cell-type classification based on the multiple parametric biomechanical cell properties with reasonable sensitivities (>65%). Applications of the confining microchannel can be further extended for high-throughput, continuous-flow deep phenotyping of rare cells by surface functionalization for both biomechanical and biochemical biomarkers for more comprehensive and promising cell characterization.