  The rheological properties of cells and tissues are central to embryonic
development and homoeostasis in adult tissues and organs and are closely
related to their physiological activities. In this work, we present our study
of rheological experiments on cell monolayer under serum starvation compared to
that of healthy cell monolayer with full serum. The normal functioning of cells
depends on the micronutrient supply provided by the serum in the growth media.
Serum starvation is one of the most widely used procedures in cell biology.
Serum deficiency may lead to genomic instability, variation in protein
expression, chronic diseases, and some specific types of cancers. However, the
effect of deprivation of serum concentration on the material properties of
cells is still unknown. Therefore, we performed the macro-rheology experiments
to investigate the effect of serum starvation on a fully confluent Madin Darby
Canine Kidney (MDCK) cell monolayer. The material properties such as storage
modulus (G') and loss modulus (G''), of the monolayer, were measured using
oscillatory shear experiments under serum-free (0% FBS) and full serum (10%
FBS) conditions. Additionally, the step strain experiments were performed to
gain more insights into the viscoelastic properties of the cell monolayer. Our
results indicate that without serum, the loss and storage moduli decrease and
do not recover fully even after small deformation. This is because of the lack
of nutrients, which may result in many permanent physiological changes.
Whereas, the healthy cell monolayer under full serum condition, remains strong
& flexible, and can fully recover even from a large deformation at higher
strain.
