Single nuclei on chip - morphological and genetic responses to actin-based deformations

In the developing organism, cells are submitted to forces that participate in fate determination. These forces may be directly transmitted to the nucleus through the actin cytoskeleton to control gene expression. Yet, the control mechanisms and their effect on differentiation are unclear. To elucidate specifically the role of the actin cytoskeleton, we combine a minimal reconstituted system and a microfluidic platform, where thousands of isolated nuclei are immobilized along with actin and actin-binding proteins. This will allow for quantitative analyses of the role of actin on physical deformation of nuclei by high-throughput imaging and on the associated changes in gene expression, notably those important for genome integrity and differentiation, by mRNA analyses such as mRNA FISH and mRNA sequencing. This interdisciplinary project combining biology, technological development, and biophysics perfectly fits the framework of “Single Cell technologies” of this call. The expected results will have a high impact in the field of cell mechanics, as well as broad implications in other fields, such as developmental biology and cancer research.

Genetically encoded soft microfluidic interfaces

Liquid/liquid or liquid/air soft interfaces are at the heart of a very large number of dispersed materials (drops, emulsions, foams) both for daily use and for industrial applications (hygiene, cosmetics, food or pharmaceutical products, for example). Interface‐rich, dispersed materials are particularly well suited for implementation in microfluidics, from their engineering to their characterization and applications. The properties of these interfaces are traditionally modulated by formulation approaches, for example by adding surfactants, colloids or polymers. This allows a fine adjustment of the properties of a given system but requires a new formulation for each system considered and makes it difficult to obtain dynamic or evolutive properties. Another approach consists in applying stimuli, such as temperature, electric field or light, which allows dynamic control but can disturb the system (important heating, for example) or require specific properties (e.g., stimulable materials, transparency for photostimulation, etc). Finally, contrary to solid/liquid interfaces, classical soft interfaces (water/oil, water/air) usually have low surface reactivity, so that their chemical functionalization remains difficult.
For this PhD project, we wish to explore a radically different way of engineering functional soft/dispersed materials and making them intrinsically tunable and dynamic. The principle consists in incorporating a DNA coding for a protein with the property of self‐assembling at the interfaces and synthesizing this protein by cellfree expression in situ. We will study in particular the cell‐free expression of BslA, a well‐documented protein involved in biofilm formation and known for its strong and various interfacial properties, as well explore the possibility to express some fungal hydrophobins that are amphiphilic proteins produced by filamentous fungi.

PHOTOBIM : Photoactive biointerfaces and microfluidics for the controlled actuation of cells

The ability of cells to perceive and respond to their microenvironment is essential for all aspects of an organism (development, life, regeneration). This project aims at developing a new biomimetic platform, where key biomolecules will be presented in a controlled manner in space and time, in order to mimic the interactions of the cells with their environment. Many signaling pathways are regulated by the joint action of soluble factors (such as growth factors) and extracellular matrix-bound ligands. The platform will thus combine microfluidics systems to control gradients of soluble molecules, with an innovative substrate allowing to reversibly present or hide a ligand upon light illumination. Our strategy is to combine the use of a PLL-g-PNIPAM copolymer approach that allows modulation of ligand accessibility upon temperature switch, with the generation of photothermal gradients in the vicinity of gold nanoparticles by thermoplasmonic excitation. As a proof of concept, we will focus on mimicking the interactions of the cells and their environment during the epithelial-mesenchymal transition. This transition is highly involved in morphogenesis and processes such as wound healing, tumour invasion, and metastasis.

Catalyst-free novel plasma-liquid micro-structured reactor for the direct oxidation of methane to liquid oxygenated fuels

The direct partial oxidation of methane to liquid oxygenates is a topic of great interest for energy sustainability and is one of the grand challenges in the area of catalysis and energy. In the existing commercial process, syngas is catalytically converted to methanol at high temperatures and high pressures. The objective of this project is to synthesize liquid oxygenated fuels (mainly formaldehyde, methanol and formic acid) by direct partial oxidation of methane in a plasma-liquid micro-structured reactor under mild conditions. The main difficulties of this process are related to the stability of the methane molecule and the reactivity of the oxygenates which may be oxidized subsequently into CO and CO2, with the consequent drastic decrease in selectivity with the methane conversion rate. In this project, we propose to overcome those limitations by developing a multiphase-flow micro-structured reactor dedicated for the in-situ extraction and protection of final products, maximizing the selectivity of the process. If successful, we aim to reach a high selectivity of 70% (Methanol, formaldehyde) combined with a total conversion of methane.

Microfluidique pour la fonctionalisation sélective de liaisons C-H

Ce projet, qui s’inscrit dans la thématique « Flow chemistry », vise à développer une méthode d’insertion de précurseurs carbéniques dans des liaisons C-H de molécules complexes au sein de microréacteurs aux parois fonctionnalisées par des catalyseurs à base de fer. Cette méthodologie combine les avantages de la catalyse hétérogène (récupération aisée du catalyseur supporté), et des systèmes microfluidiques (contrôle de la température et des temps de mélange). Ceci permet d’envisager la mise au point d’un système hautement sélectif à base d’un métal non noble, pour une transformation souvent non applicable à des molécules complexes, et dont l’état de l’art est dominé par la catalyse au rhodium.
Pour mener ce projet à bien, trois familles de catalyseurs issus de la littérature et permettant ce type de transformation en conditions batch (réacteur homogène) sur des substrats modèles simples ont été choisis. Dans un premier temps (Axe 1), ces catalyseurs seront greffés sur microbilles de verre. L’efficacité (chimio- et régiosélectivité) des systèmes hétérogènes ainsi obtenus sera d’abord étudiée sur des substrats modèles, puis sur des molécules plus élaborées. Les catalyseurs ayant obtenu la meilleure activité seront adaptés en réacteurs microfluidiques et greffés sur les parois de microréacteurs en verre (Axe 2). Une fois les conditions de réaction optimisées en régime microfluidique, la fonctionnalisation de cibles complexes sera envisagée permettant une évaluation de l’apport de la microfluidique pour cette méthodologie.

A Reactor for the emergence of EVOlution from LIfe’s building blocks (REVOLI)

The Miller-Urey experiment has revolutionized the field of the origin of life (OoL) by showing that chemical mixtures in prebiotic conditions could lead to the synthesis of life’s building blocks. We want to tackle the next step: explain how building blocks can polymerize and self-organize into compartmentalized reaction networks capable of evolution, thus making the bridge between physico-chemistry and biology.
We will set-up an experiment where mixtures of biomolecular building blocks (of RNA, peptides, lipids) are submitted to dry-wet cycles in an open reactor. This implementation of Darwin’s “warm little pond” with day-night cycles provides two key ingredients: enhanced reactivity during the dry phase, and compartmentalization of chemical networks in vesicles during the wet phase. We will study the emergence of evolution, the signature of which are an increasing complexity of biopolymers across cycles and changes in the physical properties of vesicles which correlate with their ability to persist under selection. If successful, this experiment would be the first demonstration of spontaneous emergence of evolution in a physico-chemical system. Furthermore, it would open a completely novel avenue in synthetic biology, by-passing the need to build complex artificial cells while allowing the same range of applications: it will become possible to leverage the power of Darwinian evolution

RUN Project : Drug discovery through cell migration

In biomedicine, one of the main worldwide challenges is the development of therapeutic strategies for the medical care of primary immune deficiencies (PIDs). PIDs originate from mutations in genes required for the immune function, making patients prone to infections, auto-immunity and cancer. More than 400 PIDs have been identified, affecting about 30,000 individuals in Europe, for which there is no curative treatment. Due to the high economic and societal impact, the European Union has recognized “translational research on rare diseases” as a public health priority, emphasizing the urgency for novel therapeutics.

A conductive soft granular material for water desalinization

Water being an electronically insulatingmaterial, electronic conduction between two electrodes immerged in water is solely possible by directly wiring the two electrodes. Such a wiring can be obtained by dispersing
electrically conductive particles that are connected and which form a so-called percolated network The ability to conduct electrons in an aqueous media under flow opens new strategies in the area of energy management or water desalinisation. Here, we propose to study a new concept of flowing electrodes having a high conductive
area while easily flowing. The basic principle is to encapsulate large amount of conductive particles in a polymer network shaped as beads, thus forming a soft granular material. The main objectives of the project are to upscale the production of subPmillimetre conductive hydrogel beads and to build an experimental set-up incorporating a flow capacitive deionization device.

MimeCodr : Microfluidic Metamaterials with Coiled Droplets

Using microfluidics we are able to synthetize individual resonating units. Combining many of these units, we may form a material that exhibits original optical properties. Our idea combines concepts from three fields of engineering and physics: microfluidics, elasto-capillarity and optical metamaterials. The goal of MimeCodr is to harness these physical effects in a microfluidic context for the generation of novel optical materials.

New Hybrid plasma-catalytic methanation of CO2

Au sein de l’IPGG l’équipe « Procédés, Plasmas, Microsystèmes » développe des microréacteurs plasma dans l’objectif de trouver de nouvelles voies de synthèse de molécules chimiques plus respectueuses de l’environnement. Les applications vont de la fonctionnalisation de molécules pharmaceutiques à la transformation du dioxyde de carbone en méthane.