Light-Responsive Liquid Crystal Surface Topographies for Dynamic Stimulation of Cells.

All biological surfaces possess distinct dynamic surface topographies. Due to their versatility, these topographies play a crucial role in modulating cell behavior and, when intentionally designed, can precisely guide cellular responses. So far, biomechanical responses have predominantly been studied on static surfaces, overlooking the dynamic environment in the body, where cells constantly interact with shifting biomechanical cues. In this work, we designed and fabricated a light-responsive liquid crystal polymer film to study the effect of micrometer-scale, dynamic surface topographies on cells under physiologically relevant conditions. The light-responsive liquid crystal polymers enable on-demand surface topographical changes, reaching pillar heights of 800 nm and grooved topographies with 700 nm height differences at 37 °C in water. The light-induced surface topographies increased mechanosensitive cell signaling by up to 2-fold higher yes-associated protein (YAP) translocation to the nucleus, as well as up to 3-fold more heterogeneity in distribution of focal adhesions, in a topography-related manner. The pillared topography was seen to cause a lower cellular response, while the grooved topography caused an increased mechanical activation, as well as cell alignment due to a more continuous and aligned physical cue that enhances cell organization. Excitingly, we observed that subsequent surface topography changes induced a 3-fold higher YAP nuclear translocation in fibroblast cells, as well as a 5-fold higher vinculin heterogeneity distribution, indicating that multiple cycles of topography exposure ampliated the cell response. Our work emphasizes the potential of light-responsive liquid crystal polymer films generating dynamic biomechanical cues that allow us to modulate and steer cells in vitro.