Proefschrift

Orientational Order and Confinement in Biological Tissues

This thesis investigates how cell shape and collective behavior influence the dynamics and structure of biological tissues, which are crucial for understanding processes like embryonic development, tissue regeneration, and metastasis.

Auteur: J.M. Armengol Collado
Datum: 05 februari 2025
Links: Thesis in Leiden Repository

Using a novel tool to analyze cell geometry, it was found that epithelial tissues exhibit multiscale orientational order, with hexatic symmetry at small scales and nematic symmetry at larger scales. Additionally, a hydrodynamic model was developed to capture these symmetries, aligning with numerical simulations and enabling deeper analysis of the behavior of cell clusters. The study also examines how confining liquid crystals with six-fold symmetry in channels leads to antiparallel cell flows, enhancing circulation—a vital mechanism for cell migration in small capillaries. Finally, we show that metastatic invasion can be modeled as a turbulent active nematic fluid. Interactions between the system’s walls and topological defects were found to promote more aggressive migration modes, implying potential therapeutic strategies. This work advances our understanding of active matter and provides insights into the physical principles governing tissue dynamics and cancer progression.