Institut Charles Sadron Event

My thesis work concerns both the enzyme-assisted self-assembly of peptides and the structuring of materials by reaction-diffusion processes. We have shown that by using alkaline phosphatase within a host gel and allowing a phosphorylated precursor peptide to diffuse into it, it is transformed into a hydrogelator peptide that self-assembles. As the enzymes in the gel also diffuse out of the gel, there is a concentration profile of self-assembly at the gel/solution interface followed by a depletion zone in the gel followed by a second maximum of self-assembly. This profile is the result of processes similar to those used to obtain Liesegang structures. As the enzyme concentration in the gel decreases, a transition is observed between a continuous profile and isolated self-assembling micro-globules. We have developed a model to account for all these observations. To our knowledge, this work describes for the first time the in situ and autonomous formation of organic microstructured motifs within materials, based on enzymes. It thus represents a new approach for the design of hierarchical and functional biomaterials.