[Expired] Projet de thèse au laboratoire de Chimie et Biologie des Métaux
Ecoconception et écotoxicité de nouveaux agents biocides à base de nanoparticules d’argent à enrobages bioinspirés
Au laboratoire de Chimie et Biologie des Métaux, http://www-dsv.cea.fr/irtsv/lcbm/biomet/
Silver nanoparticles (NP-Ag) are used for their biocidal properties in everyday products. However, we were able to show that they have some toxicity depending on their coating (citrate, PVP) on hepatic cells. We are studying toxicity mechanisms by various techniques in vitro and in cellulo. We propose here a multidisciplinary thesis project for the development of new eco biocidal agents based on silver nanoparticles with bio-inspired coating less toxic to humans. Indeed, our recent work allows us to observe a dissolution effect by some copper chelating proteins as well as by biomimetic chelators. During this thesis we will deepen these studies with several proteins but also phytochelatins. All the results obtained in the laboratory will then allow us to develop one or several bio-inspired coatings. Complex NP-Ag / bio-inspired coatings will then be characterized by different physicochemical methods that will allow us to study their size, charge, homogeneity, stability, and this in different environments. Then we will compare the biocidal effect of these new NP-Ag with commercial NP-Ag (PVP, citrate). We will also study their cytotoxic effects on liver cells. The objective is to improve the ratio between biocidal effect and the liver toxicity for our novel NP-Ag. At the cellular level, we want to characterize the entry pathway of these novels NP-Ag in hepatocytes, their fate in cellulo as well as cellular responses they trigger. In the last part we will also study their fate in different mesocosms. This will be conducted in collaboration with Rovaltain Research (research program in environmental toxicology and ecotoxicology). This will allow us to analyze the stability of NP-Ag in the environment and observe the changes they undergo over time. We will thus better understand the life cycle of our novel NP-Ag and compare it with traditional NP-Ag who tends to be transformed into Ag2S precipitate in soils. In the thesis, we will design and characterize novel biocidal agents based on NP-Ag with a bio-inspired coating. These biocompatible NP would be safer for humans and the environment. The proposed training will be varied (molecular biology, cell biology, biochemistry and physical chemistry). The student will work in a team expert in the study of metal homeostasis and interference with metal nanoparticles. The entire necessary infrastructure for the running of the thesis is present in the unit UMR5249 (iRTSV, CEA-Grenoble).
Le candidat devra être motivé avec de bonnes connaissances en biochimie et biologie cellulaire. Un profil Chimie/biologie pourrait aussi convenir ainsi qu’un intérêt pour la chimie bio-inorganique.
Dr. Isabelle Michaud-Soret () and Dr. Auélien Deniaud ()
Laboratoire de chimie et biologie des Métaux (LCBM)
17 Avenue des Martyrs
F-38054 Grenoble cedex 9
Tel : (33) 4 38 78 99 40
Expires on Friday April 10th, 2015