Bridging Scales and Methods in Cellular Mechanics: Integrating Microfluidic and AFM Measurements in Mouse Oocytes

The mechanical properties of cells have been correlated with their pathological states in various cell types, including, but not limited to, oocytes. In oocytes, the female gametes, mechanical properties such as cortical elasticity and surface tension have been linked to their fertilization potential. For instance, in mouse oocytes, cortical tension must be maintained within a narrow range to ensure correct asymmetric division, an essential requirement for oocyte quality. Microfluidics and Atomic Force Microscopy (AFM) are two techniques commonly used to measure the mechanical properties of cells. While microfluidic constriction offers advantages for measuring cellular mechanical properties, such as being minimally invasive, it requires an accompanying theoretical model for quantitative assessment. These models typically predict global or bulk values of the mechanical properties by analyzing the cell's passage trajectory through the constriction.AFM, on the other hand, provides local measurements, as the deformation induced at the indentation point is typically negligible compared to the overall cell size. Here, we propose a theoretical model that relates the cell passage trajectory in microfluidic constriction and the force–deformation curves obtained from AFM to the static (elasticity and surface tension) and dynamic (viscosity) mechanical properties of cells. We then compare the corresponding parameters derived from both methods through experiments on mouse oocytes.