Projets de recherche

Research Projects



SIMBAD: combining next generation SequencIng and droplet-based Microfluidics for the high throughput statistical analysis of Bio-molecule ADaptability

Authors: Andrew Griffiths

Year of completion of the grant: 2013

Darwinian processes, involving iterative rounds of mutation and selection, can be used for the rapid directed evolution of proteins in the laboratory. Directed evolution is a powerful tool to study evolution at a molecular level, to unveil fundamental aspects of protein function, and to optimize enzymes for industrial applications. However the poor current understanding of the relationship between protein sequence and function precludes the rational design of evolution trajectories, and therefore directed protein evolution proceeds often blindly towards a defined goal, resulting in frequent trapping in deadend trajectories or on local optima. Furthermore, cost and time limitations mean that typically only 103 to 105 variants can be screened per round using conventional microtitre-plate based screening systems. We propose to overcome both of these limitations by coupling the evolution of proteins using droplet based microfluidics to next generation sequencing via the barcoding of genes encoding proteins according to their phenotype. This microfluidic approach will allow cost effective, quantitative screening of large repertoires of mutants (≥106) using minimal quantities of reagents (~150 μL) and generate high resolution mapping of protein sequence versus function. This mapping will then allow navigation along well-defined trajectories and to perform much more controlled directed evolution, opening up new enzyme optimization strategies.

Détail SIMBAD: combining next generation SequencIng and droplet-based Microfluidics for the high throughput statistical analysis of Bio-molecule ADaptability

Détail SIMBAD: combining next generation SequencIng and droplet-based Microfluidics for the high throughput statistical analysis of Bio-molecule ADaptability

Développement d’un microréacteur plasma pour la catalyse de polymérisation

Authors: Michael Tatoulian

Year of completion of the grant: 2013

L’objectif du projet est de concevoir un microréacteur plasma dédié à la synthèse chimique. La réaction chimique choisie concerne la synthèse de polymères biodégradables qui représente un enjeu important. Le dispositif est novateur puisqu’il propose de déclencher une décharge électrique dans une goutte de liquide qui contient le catalyseur en solution et la molécule à polymériser. Le dispositif permettra d’apporter des éléments essentiels sur les cinétiques de polymérisation catalytiques, et ouvrira également des perspectives importantes qui pourront être utilisées au futur pour des applications environnementales en phase gaz (valorisation du CO2, traitement COV) ou liquides (traitement de polluant en phase aqueuse).
Le projet sera mené par une équipe pluridisciplinaire composée d’experts en Génie des Procédés plasmas (M. Tatoulian/S. Ognier/S. Cavadias/C. Guyon), en microfluidique (P. Tabeling, F. Monti) et en Chimie moléculaire (C. Thomas, E. Brulé). Par ailleurs, une collaboration déjà en place, entre le LGPPTS et le groupe Micro Nano Bio et Microsystèmes de l’Institut d’Electronique Fondamental, garantira un accès privilégié à la Centrale de Technologie Universitaire qui dispose de nombreux équipements impliqués dans la réalisation et la caractérisation de micro et nanosystèmes.

Détail Développement d’un microréacteur plasma pour la catalyse de polymérisation

Détail Développement d’un microréacteur plasma pour la catalyse de polymérisation

Bacterial populations in controlled micro-environments

Authors: Axel Buguin

Year of completion of the grant: 2013

The collective behavior of chemotactic bacteria (E. coli) in confined geometries can lead to striking phenomena such as accumulations or the propagation of concentration waves. The aim of this project is to perform competition experiments with different strains grown separately up to very high densities in different micro-chambers. We will study the competition between these different strains for a limited resource in nutrients. To that end, we have designed a setup where the chambers, in which the bacteria are, are isolated from the outside world by a porous membrane. The pores are too small to allow the passage of bacteria but large enough so that the nutrients and the waste can freely be exchanged with the facing reservoir. By replacing this reservoir by a microfluidic circuit it is possible to address spatially and dynamically medium containing nutrients or repellents and to follow the behavior of the different populations confronted to a limited resource of nutrients.

Détail Bacterial populations in controlled micro-environments

Détail Bacterial populations in controlled micro-environments

Label-free opto-electrochemical imaging in microfluidic devices: from point-of-care diagnosis to the tracking of single nano-objects

Authors: Frédéric Kanoufi

Year of completion of the grant: 2013

The objective is to develop “chemical microscopy” in microfluidic systems. It is based on the label-free in situ and real time optical monitoring of chemical transformation of a surface and consists of coupling optical imagery detection to electro- or bio-chemical activation of a surface. The principle and methodology have wide application ranges.
Such label-free detection in microfluidic heterogeneous assays will be developed allowing for :
i) the detection of biomolecular recognition owing to the design of new, fast and cheap label-free point-of-care diagnosis platforms and
ii) the detection of single chemical events illustrated in the optical tracking of the individual catalytic reactivity of single nanoparticles.

Détail Label-free opto-electrochemical imaging in microfluidic devices: from point-of-care diagnosis to the tracking of single nano-objects

Détail Label-free opto-electrochemical imaging in microfluidic devices: from point-of-care diagnosis to the tracking of single nano-objects

Toward ths fabrication of liquid crystalline super-atoms

Authors: Teresa Lopez-Leon et Olivier Dauchot

Year of completion of the grant: 2013

We plan to develop a new method for producing and assembling large quantities of uniform colloidal particles with a variety of controlled non-isotropic interactions. The method consists in functionalizing, with DNA-ligands, the topological defects that appear in liquid crystal shells in order to fabricate colloids with a valence, capable of mimicking atomic interactions. The fascinating way in which topological defects organize themselves on the sphere offers a powerful tool to induce inter-particle
interactions with novel symmetries. Our intention is to study the self-assembly of these unique objects to produce colloidal architectures with new symmetries, which could eventually be exploited for photonic applications.

Détail Toward ths fabrication of liquid crystalline super-atoms

Détail Toward ths fabrication of liquid crystalline super-atoms

Digitalized electrokinetic separation for biomarker analysis

Authors: Stéphanie Descroix, Laurent Malaquin, Jean-Louis Viovy

Year of completion of the grant: 2012

The development of original methods dedicated to biomarkers quantitation to improve current medical diagnosis is still challenging. The aim of this project is to develop an integrated platform able to perform multimodal biomarker analysis at ultrasensitive levels. In particular, the system will integrate a high resolution electrophoresis combined with a compartmentalization by biphasic microfluidics. This compartmentalization will allow their further quantitation through a droplet based immunoassay. This project will be validated on the early detection of biomarkers for neurodegenerative diseases, notably Alzheimer.

Détail Digitalized electrokinetic separation for biomarker analysis

Détail Digitalized electrokinetic separation for biomarker analysis

Development of a lab-on-chip device for the analysis, treatment and recycling of pharmaceuticals at trace levels water samples

Authors: Anne Varenne, Fanny d’Orlyé, Fethi Bedioui et Sophie Griveau

Year of completion of the grant: 2012

Developed to promote human health and well being, certain pharmaceuticals are now attracting attention as crucial emerging water contaminants. To deal with this concern, we aim to develop an analytical microsystem that allows selective extraction of targeted pharmaceuticals and their metabolites for the identification and quantification of these contaminants in water samples. The selectivity and sensitivity of this lab-on-chip rest on the implementation of an aptamer-based molecular capture. This will be achieved in a confined zone of the separation channel through an electrochemically induced micro-scale functionalization of its surface. Fluorescent or electrochemical detection systems will be considered as they can be easily integrated in a miniaturized system while offering high selectivity and sensitivity. Eventually, this analytical microsystem will be designed so as to be hyphenated to a miniaturized processing platform either for on-line water purification (ozone oxidation process) or for on-line recovery and recycling of the waste pharmaceuticals.

Détail Development of a lab-on-chip device for the analysis, treatment and recycling of pharmaceuticals at trace levels water samples

Détail Development of a lab-on-chip device for the analysis, treatment and recycling of pharmaceuticals at trace levels water samples

Immune system on a chip part I : maturation of denditric cells

Authors: Matthieu Piel, Ana-Maria Lennon-Duménil, Edgar Gomes, Charles BAROUD

Year of completion of the grant: 2012

The adaptive immune response, which allows organisms to develop immunity against a priori unknown pathogens, relies on a multimodal system aimed at detecting, delivering and analyzing information from peripheral tissues to trigger a response specific for the pathogen. Detection is performed by dendritic cells, which patrol peripheral tissues and engulf large amounts of material. This material is then processed and presented at their cell surface. Upon exogeneous or endogeneous triggers called ‘danger signals’, dendritic cells migrate towards lymph vessels and reach draining lymph nodes where they activate T lymphocytes, an essential step for the onset of the specific immune responses. Because it is very difficult to follow single dendritic cells and T lymphocytes through their journey inside the body, the adaptive immune response is often studied at steady state, on large populations of cells extracted at various points from different organs.

Détail Immune system on a chip part I : maturation of denditric cells

Détail Immune system on a chip part I : maturation of denditric cells

Ultrafast acoustic micromixer and applications

Authors: Patrick Tabeling

Year of completion of the grant: 2012

A multidisciplinary team of experts in acoustics (M. Tanter, O.Couture), microfluidics (P. Tabeling, F. Monti), and organic chemistry (J. Cossy, S. Arseniyadis), pool their efforts to invent a method for in-vitro (in microfluidic systems) and in-vivo high-speed micro-mixing of reagents. The method consists in dispersing the reactants in submicron droplets, then encapsulated in perfluorocarbon bigger droplets. Then, applying a focused ultrasonic wave vaporizes the perfluorocarbon, and expels, in a few microseconds, the reagents to the external phase where they can mix, under isothermal conditions. We think we can mix reagents on less than 100 microseconds time scales, and win one or two orders of magnitude compared to the fastest methods of micromixture reported in the literature. This is a great breakthrough, establishing a new generation of micro-mixers. There are many applications: in-vivo delivery of drugs and prodrugs, measurement of chemical kinetics, dynamic conformational analysis, etc. In this project, we focus on applications in the field of in-vivo delivery of drugs and prodrugs.

Détail Ultrafast acoustic micromixer and applications

Détail Ultrafast acoustic micromixer and applications

Thermo-actuated migration in a microystem, application to foam drainage control

Authors: Marie-Caroline Jullien et Florent Malloggi

Year of completion of the grant: 2012

We have recently shown that when a bubble or a drop is submitted to a temperature gradient, it migrates to the coldest region by a mechanical effect, i.e. the deformation of the PDMS causes the element to move to the area where the cavity is the thickest. We have identified some mechanisms involved in this system. We first want to make a general mapping of the response of the bubble/drop depending on different control parameters. We believe that this study may be used for future reference.

Détail Thermo-actuated migration in a microystem, application to foam drainage control

Détail Thermo-actuated migration in a microystem, application to foam drainage control

10 projects.
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