Intracellular particle tracking microrheology

Intracellular particle tracking microrheology offers a method of directly quantifying the mechanical properties of live cells from the displacements of particles embedded in the cytoplasmic region. Given the heterogeneities of architecture within a cell and between cells, the microenvironment-dependent mean square displacements (MSDs) can be used individually to estimate the local rheological properties or can be ensemble-averaged to determine the overall cellular mechanical properties depending on the biological phenomenon being examined. As such, intracellular particle tracking microrheology has been used to map the rheological properties of individual cells in more physiologically relevant conditions and monitor mechanical responses of cells to extracellular chemical and physical stimuli over long time periods (hours or days). In addition, changes in the intracellular mechanical properties, which contribute to cell shape, structure, and function, are dynamically altered by minute mechanical forces from both the extracellular environment and intracellular actomyosin contraction, and can be monitored by intracellular particle tracking microrheology. This chapter provides general information regarding particle tracking microrheology and highlights recent advancements in this field.