Mechanische transities in levende weefsels: Computationele modellen van fasetransities en morfogenese

Living tissues undergo continuous mechanical transitions to grow, remodel, and acquire shape during development and disease. These transitions reflect changes in tissue rigidity, ranging from fluid-like to solid-like states, and are governed by the collective behavior of cells and their interactions. From a physical perspective, these changes in tissue properties can be understood by the jamming phase transition. In this thesis, I investigate how cellular properties such as adhesion, friction, division, and osmotic regulation give rise to emergent tissue-scale mechanics. Using computational models inspired by active foams and soft matter physics, I establish a quantitative framework to describe rigidity transitions in living tissues. By combining theory with experimental data from embryonic development and tumor growth, this work reveals how local cell-scale processes control large-scale morphogenetic behavior. I show that adhesion can both promote and inhibit tissue fluidity depending on context, that cell-cycle variability tunes the timing of tissue fluidization, and that mechanical confinement suppresses growth by altering cellular hydro-mechanics. Together, these findings link cell-scale mechanics to tissue-level organization and provide a predictive framework for understanding morphogenesis, homeostasis, and disease.