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In their native environment cells are constantly exposed to biochemical and biophysical signals that guide and regulate complex biological phenomena. Many of these signals impact on the adhesion properties of cells, which define cell morphology, cytoskeleton arrangements and the mechanical identity of cells. Adhesion signals are far from being static, but change in time and space according to specific programmes. Non-correct display of signals may result in catastrophic events. Yet, our understanding on the effects of the dynamics of signal presentation on cell functions and fates is very limited. Here we present our recent developments in the engineering of light-responsive platforms to enable the dynamic presentation of patterns of adhesion signals whose features can be controlled in space and time. More specifically, by controlling the irradiation of azobenzene based substrates, surface topography can be altered in the time frame of few tens of seconds, allowing the formation of submicron features, i.e. a scale that interferes with focal adhesion formation. We show the potency of these substrates in stimulating individual cells with topographic patterns acting on different lengths and timescales. In particular we show how dynamic patterns rapidly alter cytoskeleton arrangements and cell mechanical properties. The development of platforms enabling dynamic signal display would provide valuable insights into cell-biophysical signal interactions and, more specifically, into mechanotransduction-related phenomena. This could pave the way towards the development of novel systems to mimic more closely physiologic or pathologic extracellular environments for in vitro cell stimulation.
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