Breast Cancer Detection using Shear Assay Based Creep Compliance and Functional Principal Component Analysis

This presents the mechanical responses of live cells that are subjected to shear flow in micro-fluidic channels under <i>in-situ</i> observation with optical, fluorescence, and confocal microscopy. The resulting time-dependent deformation of points within the cells is analyzed using Digital Image Correlation (DIC) techniques. These are used to extract deformation and strain maps of the nuclei, cytoplasm, and actin cytoskeletal structures at different stages of cell viscoelastic deformation. The measured temporal variations in strain are analyzed using Functional Principal Component Analysis (FPCA) approaches (from data science) that use time series data to extract critical features from the <i>in-situ</i> temporal creep responses of cells subjected to shear stress. Differences in the creep responses of the nuclei and cytoplasm are elucidated along with the local creep properties of the actin cytoskeletal structures of non-tumorigenic breast cells (MCF-10A), less metastatic triple-negative breast cancer (TNBC) cells (MDA-MB-468), and highly metastatic breast cancer cells (MDA-MB-231). The implications of the results are also discussed for the detection of non-tumorigenic and tumorigenic breast cells at different stages of cancer progression.<br/><br/><b>Keywords:</b> breast cancer detection, micro-fluidics, shear assay creep compliance, functional principal component analysis, time series data, cell nuclei, cytoplasm and cytoskeletal structures.