Abstract C69: Elastic properties of highly metastatic cells using nano-capillary wrinkling

Abstract

Abstract We have adapted an existing emerging method to characterize elastic properties of thin (30–150 nm) polystyrene (PS) films based on the observation of the wrinkling patterns of the film (J. Huang et al, Science 2007, 317, 650–653). Our goal is to evaluate the stiffness of cell layers cultured on top of such polystyrene films when they enter metastasis as compared to healthy epithelial cells. Recent reports using atomic force microscopy (AFM) suggest differences in cell stiffness at the local single cell level (J.K. Gimzewski et al, Nature Nanotechnology 2007, 2, 780–783). We plan to measure similar properties when cells are arranged in a sheet and compare them to AFM measurements. A relevant system is the melanoma cell lines such as A 375 and SK-Mel28, for instance. We characterized the wrinkling patterns obtained using a stereomicroscope to provide a first straightforward assessment of the elastic properties by counting the number of wrinkles and measuring their average lengths. By comparing the wrinkling pattern when either healthy or melanoma cells are grown on top of the thin PS films to that obtained when bare thin PS film floats on water and developing a theoretical model based on 2 films of different but close Young moduli associated in parallel, one can extract quantities of interest to characterize the elastic properties of normal vs. cancer cells. In addition, we propose to use digital holographic microscopy (DHM) to improve the observation of the wrinkling patterns and allow access to other relevant viscoelastic information such as relaxation of the films. Because we propose an innovative technique coupled with an emerging form of microscopy yet unexplored for cancer research, i.e. DHM, to study the mechanical elastic forces within an interconnected assembly of metastatic cells with the goal of complementing current methods of clinical diagnostic, we hope to answer the current need for new ways of studying the mechanisms of cancer. Citation Information: Cancer Res 2009;69(23 Suppl):C69.