3 ans starting from 01/10/2022

PhD position in Organic/Polymer Chemistry: Adaptative organic nanoparticles based on polymer-fluorophore conjugates for phototheranostic applications

This thesis position will be dedicated to 1) the multistep organic synthesis of fluorescent dyes with aggregation induced emission properties and bearing a functionality to attach them to polymeric carrier, 2) the preparation of polymers with tailored properties (amphiphilicity, stimuli-responsiveness) and side-chain or end-chain functionality to attach the AIEgen-dye, 3) the evaluation of self-assembly properties and characterization of the formed nanoparticles at nanoscale, 4) the evaluation of photophysical properties of dyes, dye-polymer conjugates and dyes nanoparticles, 4) the exploration of properties toward in vivo applications (photothermal production efficiency, photoacoustic response). In the framework of this project, competences in organic synthesis, polymer synthesis, photophysics and physical-chemistry and associated characterization techniques will be developed. The project is focusing on a multidisciplinary research area of great interest in academia and truly represents an opportunity for highly motivated graduate students. The selected candidate will also have the opportunity to interact proactively with a network of collaborators and will have the opportunity to use modern synthesis and characterization tools.

Context and research objectives:
Over the last decade, photothermal therapy (PTT) have attracted increasing attention as a potential alternative to other classical therapeutic approaches.1 It involves molecules or nanoparticles absorbing photons upon light-irradiation and generating heat through non-radiative relaxation pathways. To help the clinical translation of PTT, which is currently limited to a few early phase pilot trials, highly challenging research aspects concern the development of intelligent theranostic (i.e. combination of therapy and diagnostic) systems that provide efficient photothermal therapeutic effect in combination with comprehensive image-guiding strategy by fluorescence/photoacoustic imaging (PAI).
In this context, our group is interested in the use of Aggregation-Induced-Emission organic fluorescent dyes (AIE-dyes). These dyes present fluorescence capabilities when they are in an aggregated state, as well as heat production capability when the aggregation is reduced (because the molecular motion is permitted, favoring non-radiative relaxation pathway).2 Therefore, they can be very effective for fluorescence imaging, or for photothermal therapy and photoacoustic imaging, depending on the aggregation state. However, alternating between these two states by transformation around the dye environment (i.e. switch between aggregate and non-aggregate state), to benefit from both properties in an intelligent manner, is an underexplored promising strategy,3 which will be targeted during this thesis.

The main objective of this PhD project is to synthetize AIE-dyes and to attach them to side-chain/end-chain of stimuli-responsive amphiphilic polymers in order to obtain structures able to 1) self-assemble in aqueous solution and 2) switch between the two aggregation states as a function of the stimuli to achieve both photothermal and fluorescence properties in controlled manner. The final aim is to elaborate a polymeric one-component system capable to autonomously adapt from the diagnostic to the therapeutic needs via the state change strategy.

PhD work description:
This thesis position will be dedicated to 1) the multistep organic synthesis of fluorescent dyes with aggregation induced emission properties and bearing a functionality to attach them to polymeric carrier, 2) the preparation of polymers with tailored properties (amphiphilicity, stimuli-responsiveness) and side-chain or end-chain functionality to attach the AIEgen-dye, 3) the evaluation of self-assembly properties and characterization of the formed nanoparticles at nanoscale, 4) the evaluation of photophysical properties of dyes, dye-polymer conjugates and dyes nanoparticles, 4) the exploration of properties toward in vivo applications (photothermal production efficiency, photoacoustic response).
In the framework of this project, competences in organic synthesis, polymer synthesis, photophysics and physical-chemistry and associated characterization techniques will be developed. The project is focusing on a multidisciplinary research area of great interest in academia and truly represents an opportunity for highly motivated graduate students. The selected candidate will also have the opportunity to interact proactively with a network of collaborators and will have the opportunity to use modern synthesis and characterization tools.

Candidate profile and application form:
You should hold a Master/engineer degree in chemistry with specialization in organic chemistry. Prior experience in polymer chemistry, fluorophore chemistry or organic nanoparticle synthesis would be appreciated. Creativity, autonomy, reliability and organization skills are highly required, together with strong interest in multidisciplinary approach. Candidates are expected to be highly motivated and possess great team spirit to take advantage of the work in a leading research environment and potentially make breakthrough innovation. Applications should be sent to Yann Bernhard (yann.bernhard@univ-lorraine.fr). It should include a detailed CV, a cover letter highlighting how you meet the criteria, and your M1/M2 (or equivalent) grades reports.

Keywords:
Organic synthesis, fluorescent probes, polymer synthesis, photophysics, physical-chemistry, organic photothermal agent, stimuli-responsive polymers, photothermal therapy, fluorescence imaging, photoacoustic imaging

Dr. Yann Bernhard - Contacter
L2CM - Laboratoire Lorraine de Chimie Moléculaire à Nancy
Université de Lorraine

Autres offres d'emploi

Retour à la liste
3 Years - starting date flexible until march 2022

PhD position: Noble metals-free heterogeneous catalysts for lignin deoxygenation into aromatics

The PhD project will aim at synthesizing heterogeneous catalysts based on abundant metals, whose key parameters will be optimized: (i) textural properties of the supports, and in particular the stabilization of a hierarchical porosity, (ii) oxophilicity / acidity of the surface, (iii) and fine characteristics of the metals (dispersion, localization and composition). Thus, silica supports with hierarchical porosities will be synthesized, modified by the introduction of different oxide phases (ZrOx, TiOx, AlOx, ZnO), and then the metal phases (Ni, Fe, Co and Cu) will be dispersed in a controlled manner on the surface of the pores to obtain single atome to clustered supported catalysts. These catalysts will be studied for the HDO of model oxygenated molecules (m-cresol, anisole and guaiacol) under moderate hydrogen pressures (2-4 MPa) before being tested on real lignin in a reaction micropilot (IC2MP partner). The properties of the catalysts (activity, aromatic yield, and stability) will be rationalized by DFT studies conducted on the adsorption of model oxygenated molecules, taking into account the effect of H2O, CO and CO2 inhibitors (LPCT partner). All these results will allow the description of the reaction pathway and the obtaining of key kinetic data in real conditions of reaction conducted over lignin (at LRGP partner).

1 year - from 1st september 2022

Post-doctoral position in ultrafast spectroscopy of molecular photoswitches and photoactive metal complexes

One of the main projects of our laboratory (L2CM, Nancy, France) aims at the design of photoactive organic molecules and metal complexes or applications in photomedicine or photovoltaics. In this context, applications are opened for a postdoctoral fellowship position funded by the European FEDER project entitledFireLight: Photoactive molecules and nanoparticles” to investigate the ultrafast excited state dynamics of these photoactive systems. More specifically, the research program will focus on (1) the investigation of ultrafast photochemical processes behind Z/E photoisomerization of bioinspired molecular photoswitches and (2) the determination of the excited state properties of photoactive metal complexes.