A constriction channel based microfluidic system enabling continuous characterization of cellular instantaneous Young's modulus

This paper presents a microfluidic system enabling continuous characterization of instantaneous Young's modulus (E-instautaneuus) of single cells in suspension. In this study, cells were aspirated continuously through a constriction channel while cellular entry processes were monitored using a high-speed camera. Numerical simulations were conducted to model cellular entry process into the constriction channel where a visco-hyperelastic solid was used to model biological cells and the cellular friction with the constriction channel wall (f(c)) was properly addressed. Both experimental observations and numerical simulations confirmed the two-stage cellular entry process into the constriction channel: an instantaneous jump into the channel quantified by instantaneous aspiration length (L-instantaneous) followed by a creeping increase in aspiration length terminated by transitional aspiration length (L-transitional) Numerical simulations reveal that Linstantaneous and L-transitional are reversely proportional to E affected by fc regardless of other cellular viscoelastic parameters. By combining measured Linstantaneous and L-transitional with these obtained from numerical simulations, Einstantaneous and f instantaneous, which are c were quantified as 3.48 +/- 0.86 kPa and 0.39 +/- 0.11 for A549 cells (n(cell) = 199) and 2.99 +/- 0.38 kPa and 0.37 +/- 0.02 for 95C cells (ncell = 164). As a platform technology, this method can be used to characterize E-instautaneuus of various cell types in a continuous manner for cellular biophysical property characterization. (C) 2014 Elsevier B.V. All rights reserved.