Tests parallélisés sur puce à cellule de cytotoxicité aigüe de nanoparticules à morphologie contrôlée – PARTOX

Nanoparticles constitute a major innovation because their size allows the emergence of new properties for materials. Production of ultrafine particles (UFP) will exponentially increase over the next years. Applications in medical and industrial fields are being developed at incredible speed. Yet it seems that man-made nanoparticles might have deleterious effects on human health. The nature of these effects are complex and could result from various characteristics of the particles like their number, surface, shape, surface state, and content. It is also possible that other parameters are involved. Project objectives •Evaluate the risk in relation to human health of contact with nanoparticles, whether by inhalation, ingestion, or skin contact. We will evaluate their effect on lung, skin and liver cells. •Deepen the most common FPU toxicologies: ultrafine silicates, titanium dioxide and zinc oxide. Their toxic effect will be compared with their geometric, structural, physical and chemical properties. •Develop a technology allowing the characterisation of FPU cytotoxicity by analysing the phenotype of cells cultured on a 'Cell on Chip' glass slide. •Set up high content systems of analysis so as to get information on the toxicity of tested products by relaying on the fluorescent and morphological data of the studied cells. Validation of PARTOX will be realised by using three nanoparticle families: Titanium, Silicon dioxide and Zinc oxide, whether they are manufactured or appear as by-products of parametric studies. In order to correlate particle toxicity and objective physical values, physical and chemical properties of the three nanoparticle types (volume, surface, crystalline nature, chemical composition, size, 3D morphology, zeta potential, absorption property, dissolving kinetic as well as aggregation level) will be determined for each manufacturing process before and after suspension in cell medium. The Cell on chip innovating concept will allow us to study the toxicity of nanoparticles by means of highly parallel cell-based tests using nano-drops. This very technique of substituting in vitro cell-based experiments for animal testing has already allowed screening of pesticides in relation to their toxicity (STREP TOXDROP 2004-2006). Nanoparticle toxicity studies will be undertaken by using nano-drop cell cultures and will be characterised by multiparametric analyses related to cell mortality, oxidative stress, inflammation and genotoxicity of nanoparticles. In order to reproduce on the Cell on chip format the traditional evaluation of toxicity, the effect of nanoparticles will be tested on several human cell lines (lung, skin and liver). The size of the drops will allow us to consider various experimental conditions (nanoparticle concentration and type, cell type) on a single glass slide measuring only a few cm2. The high content analysis of each cell by image analysis will give us accurate information at cell level on their morphology and fluorescence property. In order to obtain an accurate phenotype describing the toxic effect within the whole cell population, these parameters will then be integrated into a database. Combined knowledge of the PARTOX consortium in image analysis, bioinformatics, physics, chemistry, toxicology and cell biology, as well as efficient and complementary testing equipments (e.g. Electronic Transmission Microscopy and nano-tomography) represent major assets when evaluating the risk of nanoparticles on human health. Expected results : •Master reproducible nanoparticle manufacturing processe •Standardise the characterising measurements in order to provide a strict and reproducible methodology to describe the biological effects. •Propose a detailed nomenclature for these particles associated with their manufacturing process and their structural and physico-chemical properties. •Describe for each class of this nomenclature the level and type of toxicity on the main target organs. Our studies could steer, thanks to this accurate screening, more comprehensive in vivo studies. They could also trigger production of safer nanoparticles.