Cell Shape Control and Related Focal Adheshion Dynamics on Aligned Fiber Networks

Cellular elasticity, a measure of a cell’s resistance to changing its shape in response to external stimuli, has been shown in the recent past to be a potential indicator of cell health [1]. A variety of methods including AFM techniques [1, 2], magnetic/optical tweezers [3, 4], and micropillar arrays [6–8] have been used to quantify cellular elasticity to identify cell disease state, including stages of progression in cancerous cells. Since cellular behavior is heavily dependent on the physical nature of the surrounding extracellular matrix (ECM), understanding mechanical cell-substrate interactions may lead to connections between the elasticity of a cell and the cell’s health state [1]. In this study, the STEP (Spinneret-based Tunable Engineered Parameters) technique is used to create suspended nanofibrous polystyrene substrates with tight control on fiber diameter and spacing in single and multiple layers. As cells interact with these various substrates, they take on repeatable configurations and allow the probing of biophysical traits. Specifically, cytoskeletal arrangements provide information on the behavior of the cell nucleus, f-actin stress fibers, and focal adhesions via paxillin staining, which allow for calculation of cellular elasticity.