Université PSL

Research Projects

L’IPGG offre des financements postdoctoraux pour des projets où la microfluidique joue un rôle central au sein des équipes de recherche membres de l'IPGG.

Nous mettons un accent particulier sur les projets "à haut risque scientifique", ceux qui sont difficiles à financer par les sources habituelles (ANR, etc.).

Nous donnons la possibilité de nous proposer plusieurs thèses pour un seul projet au sein de différents laboratoires de l’IPGG.

Nous souhaitons soutenir un ou deux projets de plus grande ampleur pour lequel, grâce à une synergie mise en œuvre au sein de l’IPGG, il sera possible de relever des défis d’envergure.



Mechanobiology of cell migration in complex environments

Team:
BIO6
​Project leader:
VARGAS/PIEL/DESCROIX/SEPULVEDA
Year:
2017

Cell migration is a fundamental function for life from simple unicellular to complex multicellular organisms. In vertebrates, cell motility is essential for embryo development, tissue repairing and immunity. From an immunological point of view, defects on cell migration can lead to autoimmune diseases, hyper inflammation and cancer metastasis, highlighting the relevance of this process and its therapeutic potential. The aim of this project is to decipher the specific mechanisms used by cells to migrate in tissues. To address this question, we propose a collaborative project with the MMBM group to study directed cell motility in in vitro molded tissue compartments. Using this system, we will identify specific cytoskeleton rearrangements used by cells to migrate in complex environments. This proposal focuses on leukocytes, specialized in the fast colonization of secondary tissues during infections. From an applied point of view, collaborative work with the Institut Imagine (Hôpital Necker) will help us to test our hypothesis in a physiologically relevant context. The knowledge generated with this study will help to understand the cellular requirements that allow and optimize cell displacement in the diverse and complex geometries of organs in health and disease.


Magnetic manipulation of individual chromosomes in living cells using microfabricated micromagnet arrays

Team:
LOCCO
​Project leader:
DAHAN/DESCROIX/PIEL/CROQUETTE
Year:
2017

Understanding the physical properties of the nucleus has become a major challenge in cell biology. Here, we propose to develop a novel approach based on advanced magnetic manipulation of nuclear constituents at the single cell level. We will implement biocompatible micromagnet arrays (MMAs) and finely characterize their properties using optical magnetometry. With MMAs, we will manipulate individual chromosomes in live cells and analyze their rheological and elastic response to mechanical forces. Overall our approach will shed a new light on the mechano-biology of the genome.


"Candida albicans on chip" Development of a quantitative phenomics of C. albicans, and study of the biophysical mechanisms of infection in "organ-on-chip" microfluidic devices

Team:
MMBM
​Project leader:
C. Villard
Year:
2017

Fungi are ubiquitous in our environment. The fascinating ability of these organisms to produce extended filamentous networks is at the origin of their massive colonization of the biosphere and one of the keys to their pathogenicity. We propose in this collaborative project a biophysical study of filamentous growth of the human microbiota fungus Candida albicans. A first objective will be to use microfluidic tools to develop a set of quantitative biophysical observables of the growth of C. albicans. In a second step, we will carry out an "organ-on-chip" approach to study the interactions between hyphae and animal (epithelial, dendritic) cells. Our goal is to develop new experimental and conceptual tools allowing a fine phenotypic characterization of filamentous fungi associated with their genotype, as well as a deeper understanding of the mechanisms associated with their invasive properties.


Plastic damage of amorphous materials : mesoscopic study

Team:
MMN
​Project leader:
Elisabeth Bouchaud
Year:
2017

We will prepare concentrated emulsions of different structures with a microfluidic device, which can further be cross-linked, in order to make model amorphous 2D materials with controlled density and cohesiveness. These amorphous structures will have a « basic atom » of size ~50µm. They will be fractured in a controlled way, and plastic events, i.e. local irreversible rearrangements occurring around the crack tip, will be observed in conventional and confocal microscopy. Their influence on the fracture path and on the fracture dynamics will be studied. The obtained results will be compa-red to theoretical predictions, and to the results of numerical simulations. This study could be the basis of constitutive laws for soft amorphous materials.


Graphene oxide membranes for new routes in water-ethanol separation

​Project leader:
Alessandro Siria
Year:
2017

The depletion of fossil fuel resources and its increase in global demand lead to the development of alternative sustainable energies replacing fossil fuel. The biofuels, such as the ethanol and butanol, have recently attracted great attention, both in fundamental researches and industrial applications. Biofuels are attractive due their diverse resources, such as sugarcane, wheat, corn, lignocellulosic biomass, and crop waste residues. Standard technologies to produce and purify biofuels (fermentation and pervaporation), however, are not very efficient energetically. While membrane reverse osmosis approaches would be much less costly, the attempts to fabricate membranes that are semi-permeable to ethanol but not to water were merely unsuccessful. In this project, we propose here to develop a new class of membranes made of a multistack of graphene and graphene-oxide layers for the separation of water-ethanol mixtures. Based on a theoretical and numerical prediction obtained in our team, showing that GO membrane are self-semi-permebale, we expect this graphitic membrane to allow for the separation of water from alcohol across this membrane. Preliminary experimental result confirm this unique property, which remain to be thoroughly investigated. This is the aiom of the present project. It will allow to develop a completely new and highly attractive method for water-ethanol separation.


Mechanical competition between normal and tumorigenic tissues

Team:
PBME
​Project leader:
Isabelle Bonnet
Year:
2017

At the early stages of carcinogenesis, one or few transformed cells are surrounded with normal cells. It is now admitted that the interactions of tumor cells with their wild-type neighbors are key regulators in tumor progression. However, the understanding of the interactions between normal and transformed cells at the tissue level is poorly explored since a natural question is “what happens if mutation occurs in more than one cell?”
We use light-inducible oncogene to investigate the interactions between a cluster of transformed cells at the initial stage of tumorigenesis and their normal neighbors. Our model system is the monolayer culture of MDCK cells expressing, upon blue-light-induction, src oncogene. Using blue-light pattern, we are thus able to define the cell transformation pattern inside the monolayer. Such light-activation of src in a circular domain inside the monolayer results in the formation of three-dimensional multicellular aggregates. We aim at mapping mechanical forces during this collective extrusion process. This project will thus explore how mechanical forces regulate collective invasion.


Microfluidic mimics of alveolus for mechanistic understanding of nanoparticles translocation through respiratory system

​Project leader:
Yong Chen
Year:
2017

Actually, the daily exposure of ultrafine particles to human body goes from 20 to 500 g/m3 and the respiratory system is certainly the most critical route of such an exposure. While the fine particle passages through the alveolar epithelium barrier is the key issue for non-desired inhalation, the pharmacological delivery of drug through lung system is one of important subjects in nanomedicine. In both cases, there is still a lack of mechanistic understanding about the interactions of nanoparticles with human pulmonary alveolar barrier. To overcome this shortage, we propose an in-vitro model made of human alveolar epithelium and endothelium formed on a monolayer of elastic fibers which mimic structurally and functionally the human alveolus. In particular, we propose to use human induced pluripotent stem cells (hiPSC) and microfluidic device to build alveoli-on-chip systems, together with a high precision flow control setup, to study nanoparticles crossing alveolar barrier.


Gas-Liquid plasma microreactors for CO2 valorization

Team:
2PM
​Project leader:
TATOULIAN/LESCOT
Year:
2017

The objective of the work is to synthesize organic compounds using CO2 as a raw material in gas-liquid plasma milli-reactors, a totally new technology developped these last years in IPGG. There is now a great interest to produce CO from CO2 and directly uses in-situ CO molecules as a reactant for synthesis reactions of industrial interest. In that context, the project aims to study the plasma dissociation of CO2 into CO followed by the direct reaction of CO with organic molecules injected as liquids in the diphasic plasma micro-reactors. Two chemical routes will be explored: (i) a well known catalyzed liquid phase reaction currently used for the synthesis of biologically relevant compounds (a classical aminocarbonylation reaction catalyzed by Palladium) and (ii) gas phase reactions between CO and the plasma-generated radicals formed from selected organic substrates.


New miniaturized tools with selective sorbents based on molecularly or ion imprinted polymers for the analysis of compounds at trace level in real samples

Team:
LSABM
​Project leader:
V. Pichon
Year:
2017

Miniaturized devices have enormous benefits since they save time and reduce the consumption of reagents and solvents, but they also lead to a dramatic decrease in the separation power and in the injected amounts, which is a serious limitation when the target analytes are at trace-levels in complex samples. This project aims to integrate a sample pretreatment step to extract and concentrate the target analytes, based on a selective mechanism with molecularly and ion imprinted polymers synthesized in situ, to prevent from the simultaneous extraction and concentration of interfering compounds. After optimizing the synthesis conditions, the protocols to selectively extract and preconcentrate the target analytes present in complex real samples will be optimized and validated. Next, the target analytes will be released and will be separated and specifically detected with a printed electrode or by LED induced fluorescence after complexation with a custom-developed probe. Both high selectivity of the polymers and specificity of the detection modes should compensate for the lack of performance of the microsystem separation step. Dopamine and other neurotransmitters in biological samples and lanthanide ions in environmental samples will be the model analytes and samples of this project.


Statistical exploration of fitness gradients

Team:
LBC
​Project leader:
Clément NIZAK
Year:
2016

Fitness landscapes determine evolutionary dynamics, in analogy to energy potential landscapes that rule dynamics of physical systems. Given their extremely high dimension (typically 10200), mapping exhaustively protein fitness landscapes and harnessing their local and global structure is impossible. Thus, how much local fitness gradients can be used to infer long term Evolution is still an open question. Here we will probe the local fitness landscape gradient near 103 protein-encoding genes by characterizing phenotypic properties of their sequence space neighborhoods. For this, we will measure the individual phenotype of thousands of point mutants in their neighborhood following our droplet microfluidics-based large-scale genotype-phenotype mapping strategy. Next we will relate the outcome of many long-term evolution trajectories starting from each original gene with the local fitness gradients in their neighborhood. We will next set up an extension of our technology to directly select genes according to the phenotypic distribution and local fitness gradient in their neighborhood (instead of their current fitness), opening up to the direct selection for evolvability of protein-encoding genes.


36 projects.