A Novel Technology for Simultaneous Tensile Loading and High-Resolution Imaging of Cells

A variety of methods have been used to study the tensile properties of cells or the influence of tensile loading on cellular function. Such methods are frequently limited either by cellular detachment or by an inability to image cells at high temporal or spatial resolution. Previously, we preserved cellular adhesion during loading and imaging by using a flexible silicone membrane inverted over a glass coverslip. This enabled high magnification real-time imaging of subcellular structures but chemical and physical access to the cells was limited due to geometric constraints. In this study, we present a method to integrate thin films made from poly(dimethylsiloxane) (PDMS) into a novel device. The optically clear PDMS thin films allow simultaneous tensile loading and high magnification microscopy without the need to invert the cells, maintaining physical access during experiments. To characterize the utility of this technology, we evaluated fabrication conditions for optimizing the geometry, durability, and uniformity of these films. Additionally, we demonstrate the suitability of this device for use in high-magnification, live-cell fluorescence microscopy by examining the response of the cytoskeletal protein actin, expressed in cultured primary sensory neurons, to a tensile load. This technology offers considerable potential for extending our understanding of mechanical influences on cellular function at a variety of spatial and temporal scales.