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27 mars

Kevin Alessandri et Khanh Dao Duc

13h à 14h30

Les séminaires de Kevin Alessandri (Institut Curie) et Khanh Dao Duc (IBENS) auront lieu dans l’amphi Urbain ESPCI, 10 Rue Vauquelin, Escalier N

The cellular capsules technology : Applications to investigate model tumor progression and to engineer tissues in vitro (Kevin Alessandri, Institut Curie)

Although recognized as an important step towards better understanding of tumor progression and tissue morphogenesis the use of three-dimensional in vitro cellular assays is still limited, especially due to the difficulty in establishing simple and robust protocols for their formation. We developed a microfluidic method to produce empty spherical shells and tubes with radius of 100µm in elastic, permeable and transparent hydrogel, namely sodium alginate, around living cells. This allowed us to investigate the effect of confinement on model tumor progression in spherical and cylindrical geometry. Finally, slight adaptation of the protocol allowed us to use the alginate inner wall as a template and coat it with a thin layer of extra-cellular matrix proteins. The disruptive innovation was to integrate the cells’ microenvironment within a culture vessel that protect them from mechanical stress. This opens a new avenue for integrating 3D cell culture systems in the existing biomedical industry processes.

Stochastic models in biology : Modeling and analysis of stochastic chemical reactions in cellular micro-domains, Up & Down states in cortical networks and telomere dynamics (Khanh Dao Duc, ENS-IBENS)

Uncertainty and randomness play a central role in many processes in biology. To understand such stochasticity, the goal of my PhD was to develop mathematical methods to answer some biological fundamental questions raising in various contexts, from molecular to cellular level. I will mainly present three of them. First, how to study threshold activation for stochastic chemical reactions, with applications to parameter estimation for cellular division control and mRNA transcription. Secondly, how to determine neuronal noise induced transition between Up & Down states cortical neurons, by studying a class of randomly perturbed dynamical system. And finally, how to model and predict the distribution of telomere lengths in a cell, as a determinant of cellular ageing.