Diffusion mediated rigidity-gradient hydrogel substrate for cellular mechanosensing

Mechanical cues in the cellular micro-environment play pivotal role in several important biological processes. The rigidity of the substrate has been shown to dictate the cellular morphology through the reorganization of the actin cytoskeleton. Substrates with spatially varying rigidity are most often used to investigate the coupling of the substrate rigidity and intracellular mechanosensing machinery. Here, we present a simple yet effective method for producing hydrogel substrates with a tunable rigidity gradient. Using atomic force microscopy and epifluorescence microscopy, we have characterized the substrate in terms of rigidity. Furthermore, we have investigated the cellular response on these substrates with spatially varying rigidity.