Soutenance de thèse : Hugo Le Roy

Elasticity of self assembling bio-materials

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Hugo Le Roy

Hybrid PhD defense: onsite + zoom (https://cnrs.zoom.us/j/95416861091?pwd=NlhHOW9BWXM2aDN4UmJSSktpYTZmQT09 Meeting ID: 954 1686 1091 – For pwd, please contact martin.lenz@universite-paris-saclay.fr)

Self organization is crucial for the wealth of living systems, both at the molecular and cellular level. To correctly achieve their role a tight control over the shape and structure of protein for instance, is required. Any mistake can lead to various disease like Alzheimer, where proteins aggregate into fibrous structures. On a larger scale, cells need to probe the mechanical response of their environment -the extra cellular matrix- and to adapt their own rigidity to collectively orientate. In this thesis, we are looking a two different models. In the first part, we study protein aggregation beyond the microscopical details. By considering elastic assembling particles, we are able to derive generic law and understand the very persistent formation of fibers. In the second part, we model the dynamical response of a fashionable class of hydrogels for their bio-compatibility. Material engineers are now able to synthesize materials with more and more subtle behavior, although understanding certain emergent properties -such as non-exponential relaxation- can be a major challenge. We design a simple model for the dynamical response of hydrogels connected by large multivalent crosslinkers. We are able to account for experimental results,and rationalize their origin.

Jury :

Thibaut Divoux, Laboratoire de Physique ENS Lyon, examinateur

Greg Grason, Univ. of Massachusetts Amherst, rapporteur

Martin Lenz, LPTMS, directeur de thèse

Emmanuel Trizac, LPTMS, examinateur

Emanuela Zaccarelli, Univ. La Sapienza, rapportrice

Zorana Zeravcic, Laboratoire Gulliver ESPCI, examinatrice

Date/Time : 04/10/2021 - 13:30 - 17:30

Location : Petit amphi, bâtiment Pascal n° 530