Measuring elastic properties of highly metastatic cells using nano-capillary wrinkling

Measuring elastic properties of cells has gained importance in the study of malignant transformations. The stiffness of a cell, which is technically referred to as the modulus of elasticity or Young's Modulus, E, is the measure of the amount of cell deformation caused by an applied known force. In vitro studies have shown that cancer cells have much lower elastic stiffness than normal cells. These stiffness measurements and their differences can be used to study the behavioral mechanics of how cancer cells grow, profligate, and die in a patient. Another important use of this difference in elasticity is in cancer detection. In this study, we explore the viability of measuring the elastic modulus of cancer cells by using a method that only requires the use of a low magnification microscope and a digital camera. In particular we are interested in applying the previously reported relationship between the wrinkling of thin films and the elastic properties of freely floating polystyrene (PS) films. Our work extends the scope of previous thin film studies by evaluating wrinkle formation in floating polystyrene films coated with biological cells. Our results show that the wrinkle formation is modified, both in morphology and in size, by the presence of a cellular monolayer on top of the PS film.