Uniaxial cell stretching device for live-cell imaging of mechanosensitive cellular functions

Abstract

External mechanical stretch plays an important role in regulating cellular behaviors through intracellular mechanosensitive and mechanotransductive machineries such as the F-actin cytoskeleton (CSK) structures and focal adhesions (FAs) anchoring the F-actin CSK to the extracellular environment. Studying the mechanoresponsive behaviors of the F-actin CSK and FAs in response to cell stretch has great importance for further understanding mechanotransduction and mechanobiology. In this work, we developed a novel cell stretching device combining dynamic directional cell stretch with in situ subcellular live-cell imaging. Using a cam and follower mechanism and applying a standard mathematical model for cam design, we generated different dynamic stretch outputs. By examining stretch-mediated FA dynamics under step-function static stretch and the realignment of cell morphology and the F-actin CSK under cyclic stretch, we demonstrated successful applications of our cell stretching device for mechanobiology studies where external stretch plays an important role in regulating subcellular molecular dynamics and cellular phenotypes.

On‐chip assessment of human primary cardiac fibroblasts proliferative responses to uniaxial cyclic mechanical strain

“…With particular respect to the pneumatic commercial platform FlexCell (FlexCell International Corp., Hillsborough, NC) it has been demonstrated that it suffers from limitations in terms of strain field non‐uniformities, calibration issues, operational complexities, and low‐throughput (Colombo et al, ; Vande Geest et al, ). In motor‐driven uniaxial stretching platforms, where the stretched culture membrane sides are free to deform, the resulting strain field typically has a longitudinal component along the direction of motion of the motor but also a transverse, non‐negligible, component (Shao et al, ). In summary, available culture platforms often apply different strain fields to 2D cell cultures in terms of directionality (biaxial, uniaxial, equi‐biaxial) and the level of control on the strain field uniformity is often insufficient to conduct systematic and comparable biological studies.…”

High Throughput Mechanobiological Screens Enable Mechanical Priming of Pluripotency in Mouse Fibroblasts

“…As the membrane is expanded, the cells are exposed to mechanical strain through their coupling to the flexible membrane. The expansion of the membrane can be induced through the displacement of a piston, (Baker et al, 2008;Schaffer et al, 1994) pneumatic suction (Zhong et al, 1998) or direct traction on the membrane (Shao et al, 2013). Systems using a rotational motor with a cam to drive piston motion are limited in that they can apply only one waveform without modifying the cam shape (albeit at varying frequencies) (Schaffer et al, 1994).…”

Cyclic Strain Enhances Cellular Uptake of Nanoparticles

“…Other studies also reported that repeated stretches resulted in the trafficking and remodeling of caveolin-3-rich membrane domains and accelerated turnover of membrane glycosphingolipids [29]. The mechanical strain effects on the cytoskeleton also play an important role in mechanotransduction [30,31]. The changes in the arrangement of the cytoskeleton and the stretch-induced unfolding of caveolae might reflect the mechanisms of the cellular adaptation to mechanical strains which may affect endocytosis events [32].…”