Cell response to exogenous cues is the result of a complex integration of multiple biochemical/biophysical signals, which might occur simultaneously and might be characterized by specific spatial and temporal patterns. Among these signals, surface topography plays an important role in affecting cell functions and fate. However, the current understanding of the interplay between cells and topography relies on static environment. Here the intrinsic light-responsive properties of azopolymers and the versatility of laser-based confocal microscope technique is exploited, aiming to induce spatio-temporal dynamic topographic changes in situ during cell culture. Diverse patterns can be designed on cell-populated azopolymer films with high control on time, space, and on-off signal modification. The technique proposed in this study enables the development of synthetic platforms that finely control cell orientation and migration both in time and space. The results may pave the way to unravel complex processes involved in cell-topography interactions, thus allowing to define the spatio-temporal features that most effectively influence cell functions

Biophysical and biochemical signals of material surfaces potently regulate cell functions and fate. In particular, micro- and nano-scale patterns of adhesion signals can finely elicit and affect a plethora of signaling pathways ultimately affecting gene expression, in a process known as mechanotransduction. Our fundamental understanding of cell-material signals interaction and reaction is based on static culturing platforms, i.e., substrates exhibiting signals whose configuration is time-invariant. However, cells in-vivo are exposed to arrays of biophysical and biochemical signals that change in time and space and the way cells integrate these might eventually dictate their behavior. Advancements in fabrication technologies and materials engineering, have recently enabled the development of culturing platforms able to display patterns of biochemical and biophysical signals whose features change in time and space in response to external stimuli and according to selected programmes. These dynamic devices proved to be particularly helpful in shedding light on how cells adapt to a dynamic microenvironment or integrate spatio-temporal variations of signals. In this work, we present the most relevant findings in the context of dynamic platforms for controlling cell functions and fate in vitro. We place emphasis on the technological aspects concerning the fabrication of platforms displaying micro- and nano-scale dynamic signals and on the physical-chemical stimuli necessary to actuate the spatio-temporal changes of the signal patterns. In particular, we illustrate strategies to encode material surfaces with dynamic ligands and patterns thereof, topographic relieves and mechanical properties. Additionally, we present the most effective, yet cytocompatible methods to actuate the spatio-temporal changes of the signals. We focus on cell reaction and response to dynamic changes of signal presentation. Finally, potential applications of this new generation of culturing systems for in vitro and in vivo applications, including regenerative medicine and cell conditioning are presented.