Molecular programs and active matter appear as two key ingredients for the emergence of shape in living systems. The former process chemical information, while the latter generates long-range mechanical forces. The coupling of these two elements is thus essential for the synthesis of life-like materials. This knowledge is employed for the development of life-like synthetic materials. However, the chemo-mechanical coupling in vitro remains challenging. A promising route for engineering such a coupling relies on stimuli-responsive synthetic hydrogels that change their macroscopic shape through a reorganization at the molecular level. This can be achieved by external chemical cues (as in shape-shifting DNA hydrogels) or internal force-generating systems (as in active gels). In this Marie Skłodowska Curie Action (MSCA), the Fellow aimed at the preparation of a first-ever synthetic biocompatible material that can mimic natural morphogenesis. Inspired by nature, such material was planned to be prepared by coupling of two essential processes: chemical reaction to produce morphogenetic substance; and mechanical forces for the shaping of the matter. The programmable production of the morphogen can be achieved by an out-of-equilibrium DNA-based chemical network which predictably generates single-stranded DNA morphogens. Combined with diffusion, the concentrations of the morphogen can be patterned with unique spatiotemporal precision, including travelling waves and stable fronts, which were pioneered by the host group. The autonomy of morphological structuring can be accomplished by linking the mechanical activity of active gels, composed of DNA-kinesins and microtubules, to the presence of the DNA morphogen. The latter acts as a cross-linker creating the clusters of kinesins and thus guiding the self-organization of the soft material by the collective action of nanoscale kinesin motor proteins which exert force on microtubules.
The formal objectives of the project are to (a) develop the mechanism of triggered activation of the motility of the active gel; (b) optimise out-of-equilibrium DNA-based reaction for the required experiment and (c) couple the production of the DNA morphogen with the microtubule/kinesin based active matter. Another goal of the project was to investigate the dependence of the concentration gradient of the kinesin motor protein on the motility of the microtubules.
