Supramolecular materials can be considered as living chemical systems since they rely on non-covalent, dynamic bonds and can thus be responsive to external stimuli. Yet the drawback of the weakness of the interactions between the constituting molecules is that the materials often show weak mechanical strength. This difficulty has been circumvented by incorporating supramolecular hydrogels into "permanent" (host) gels (agarose for example). The non-permanent character of supramolecular assemblies has judiciously been exploited by nature allowing cells to respond to their environment: actin fibers play an essential role in cell motility for instance. Nature controls the supramolecular assembly both in space and time through enzymatically initiated self-assembly, the enzymes transforming locally proteins from a "non-interacting" into an 'interacting" state. Spatial control of these self-assemblies is carried out by specific localization of enzymes (i) at biological interfaces or (ii) through local concentration gradient distributions in cells or tissues. Temporal control is ensured by production of enzymes at a suitable moment. Such processes can be mimicked by using enzyme-assisted self-assembly (EASA). In EASA, enzymes are used to transform non self-assembling molecules into self-assembling ones and initiating the formation of supramolecular networks. Our goal is to develop a new generation of dynamic and spatially structured hydrogels based on EASA of low molecular weight hydrogelator (LMWH), such as peptides, taking place in host gels and leading to supramolecular networks interpenetrated with the host hydrogels. In addition our goal is to localize the self-assembly processes by distributing the enzymes in a predefined manner in the host gel or around functionalized mesoscopic particles embedded in the host gel. This should allow introducing supramolecular network gradients extending over length scales ranging from centimeters down to a few 100 nanometers within the host gel. The presence of a network in the host gel should also change its mechanical properties over such length scales. Mechanical properties are important parameters guiding cell adhesion processes and stem cell fate. Both aspects will be investigated featuring interesting applications in tissue engineering. Based on our strong expertise and also our very recent developments in the trigger and control of supramolecular networks under the action of alkaline phosphatase we will use this enzyme to localized the self-assembly of LMWH within a host hydrogel. We will use hydroxypropylmethyl cellulose (HPMC) functionalized with silanol groups as host gels because they proved to be very weakly interacting with cells. This will allow initiating cell interactions specifically through the supramolecular network. New types of HPMC gels incorporating hyaluronic acid will also be developed in order to render the host gels degradable in time for cell development within the material. We will in particular investigate the effect of network gradients on cell migration processes and how the supramolecular network can be used to guide stem cell differentiation with embedded cells. The great interest of our gels is that their properties can be tuned both in space (localized EASA) and in time by programmed addition of peptides onto the host gel. This opens new opportunities for cell guidance that will be explored. The EASA project relies on the complementarity of three research groups: one expert in surface chemistry and supramolecular assembly (ICS UPR22-CNRS), a second one who developed highly suitable hydrogels (HPMC) for cell viability over very long times (INSERM U1229) and a last one who has a strong experienced in biomaterials and tissue engineering (INSERM U1121).