In the past years, with the tremendous progresses made in the area of nanotechnologies and materials science, a huge diversity of engineered nanomaterials has been continuously elaborated. The uncertainty about the novel properties of these materials, which strongly depend on the particle size, shape and composition, and how that may relate to nanoscale operations at the biological level, has generated considerable concerns and could impact the implementation and acceptance of this new technology by the society.
The aim of this project is to characterize the toxicity associated to nanomaterials using ZnO quantum dots (QDs) as model. QDs are photoactive nanoparticles with a wide range of application ranging from photovoltaics to fluorescent bio-imaging. It has recently been demonstrated that QDs exhibited higher cytotoxicities than those of their components taken independently. This toxicity has at least two origins, a metal leakage from the core, and the production of reactive oxygen species (ROS), with a relative contribution of each that remains relatively difficult to evaluate. If the metal leakage is related to the composition and the stability of the nanoparticle, the ROS production is linked to its reactivity and its surface chemistry. With this project, we would like to set the basis of the relationship existing between the chemical structure, the stability and the toxicity of ZnO QDs.
The scientific program proposed is divided in three parts: (i) the design and engineering of 12 ZnO QDs and the evaluation of the relationships between the nanoparticles properties and their toxicological effects. Different surface ligands will be used in order to develop different kinds of interactions between the materials and the bacterial cells used as biological model. (ii), second, the evaluation of stability, both in the absence and in the presence of biomaterial, using original and innovative approaches including mass spectrometry and biosensing of Zn2+, and (iii) the evaluation of the QDs’ toxicity on bacteria using home made toxicity tests based on growth kinetics, the evaluation of cell membrane integrity and enzymatic activities after exposition to QDs, the evaluation of ROS-associated damages, and finally the use of a complete array bacterial stress response biosensors. In addition, the adaptability towards the newly engineered materials will be determined in order to evaluate the way bacteria could cope to newly engineered “anthropogenic pollutants”. Our work should allow to set the basis of an algorithm dedicated to the reliable prediction and assessment of the possible spectra of effects, from benefits to possible risks, and health hazards associated with exposure to nanomaterials as they become more widespread, pervasive agents in manufacturing and medicine.
IS2M, LRC 7228 CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE - DELEGATION REGIONALE ALSACE
ANR grant: 440 000 euros
Project ID: ANR-11-CESA-0004
Monsieur Raphaël SCHNEIDER (CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE - DELEGATION REGIONALE CENTRE-EST)
The project coordinator is the author of this abstract and is therefore responsible for the content of the summary. The ANR disclaims all responsibility in connection with its content.