Mechanical Response of Living Cells to Contacting Shear Forces

Cells adjacent to implanted devices often experience stress in the form of shearing forces from relative motion with those devices. Cell response to contacting shear, specifically in the reorganization of the cytoskeletal actin fibrils, is not yet fully understood. Many techniques such as atomic force microscopy and micro-pipette aspiration are currently used to deform or stress cells in a controlled way. Assessments are typically measured changes in mechanical, fluid, or biochemical properties. Novel micro-friction measurements between a living cell monolayer and a hydrogel material with fluorescence microscopy analysis provide insight into the mechanotransduction of stresses, actin fibril densification in the contacted zone, and the time scales involved in the cellular stiffening response. This type of measurement is sensitive enough to cause an in situ response without killing the cells, and could be used to understand more about the nature of cellular response to applied stresses and wound healing.