Characterizing cell shape with a single number
Characterizing cell shape with a single number lead image
It is essential to determine the parameters of a cell’s shape to analyze their mechanical properties as label-free biomarkers for cell function. So far it has been possible to parametrize adherent cells but doing the same for suspension cells such as blood cells, which are important for our immune defense, has been elusive.
Fregin et al. describe a method to characterize cell shape with a single number. Their results demonstrate that the characterization of cell shape and cell descriptor depends on environmental conditions such as in which direction and by how much cells are being stretched.
The researchers were able to systematically compare nine different shape descriptors for two different hydrodynamic geometries of cells passing a microfluidic constriction. Usually, cells need to be in a steady state in response to a mechanical stress to calculate elasticity and viscosity, like a spring that needs some time to adjust to an external load, but this method allowed measurements to be taken while the cells were in flux.
“We were surprised we could predict material properties such as elasticity and viscosity of cells from “incomplete” measurements,” said Bob Fregin.
This classification of cellular shape descriptors is essential for an application of cell mechanical properties as a label-free biomarker in fundamental and translational research.
In this experiment the researchers focused on single cells in suspension. Future studies will be aimed at quantifying the shape of 3D tissue models. This research will also enable different research groups to compare analyses of work on the mechanical properties of suspension cells.
“Shape description is relevant beyond mechanical properties and single cells,” said co-author Oliver Otto. “It can also determine cells’ volume or characterize multicellular aggregates.”
Source: “Interpretation of cell mechanical experiments in microfluidic systems depend on the choice of cellular shape descriptors,” by Bob Fregin, Doreen Biedenweg, and Oliver Otto, Biomicrofluidics (2022). The article can be accessed at https://doi.org/10.1063/5.0084673 .
