Virtual fluidic channels: from functional single cell rheology to tissue mechanics
The mechanical properties of cells have long been established as a sensitive and label-free
biomarker. While mechanical cell assays have been traditionally limited to low throughput or
small sample size, the introduction of real-time deformability cytometry (RT-DC) increased
analysis rates to up to 1,000 cells per second. RT-DC has demonstrated its relevance in basic
and fundamental life science research, e.g. by observing the activation of immune cells and
describing the membrane dynamics of Malaria pathogenesis. However, linking immune cell
activation to underlying tissue alterations has not been possible so far.
Here, the concept of virtual fluidic channels is introduced to bridge the gap between single
cell rheology and tissue mechanics. Virtual channels can be created in almost any
microfluidic geometry and can be tailored dynamically towards hydrodynamic stress
distributions sufficient to probe the rheology of arbitrary cell sizes. Using spheroids as a
tissue model, results from virtual channel measurements indicate that the Young’s modulus
of single cells exceeds the one of spheroids and that their elasticity increases with size.