Auteur / Autrice : | Muhammad Yasir Javed |
Direction : | Christian Ricolleau |
Type : | Thèse de doctorat |
Discipline(s) : | Matière condensée et Interfaces |
Date : | Soutenance en 2015 |
Etablissement(s) : | Sorbonne Paris Cité |
Partenaire(s) de recherche : | autre partenaire : Université Paris Diderot - Paris 7 (1970-2019) |
Mots clés
Résumé
A key concern raised by the development of nanotechnology is the long term fate of nanomaterials in their environment, and particularly the control over inorganic nanoparticles (NPs) full life cycle in the organism and related risks for human health. Most toxicology studies take the point of view of living organisms to examine the effects of exposure to NPs on biological functions. Here, we propose an original "Materials Science" approach to the nanotoxicology paradigm: we choose to take the point of view of nanomaterials in order to monitor the transformation and degradation of their atomic structure and physical properties in living environment and then unravel the mechanisms determining their fate. We have exploited the multifunctionality of aberration-corrected transmission electron microscopy to follow the biodistribution and the structural evolution of inorganic NPs (iron oxide, gold, cobalt ferrite) injected into biological media (solution mimicking the intracellular environment and mice). These nanoscale investigations were complemented by the magnetic follow-up of the injected NPsin order to quantify the NPs at the macro-scale and follow the evolution of their magnetic properties. This multi-scale approach allowed us to characterize for the first time, the the degradation and recycling mechanisms of iron-oxide nanoparticles and to provide relevant insightsonthe relations between the initial structure (size, shape, composition. . . ) and the life cycle of inorganic NPsin the organism.