Silvia Diabaté 1, Lucie Armand 2, Sivakumar Murugadoss 1 , Marco Dilger 1 , Susanne Fritsch-Decker 1, Christoph Schlager 3, David Béal 2, Marie-Edith Arnal 2, Mathilde Biola-Clier 2, Selina Ambrose 4, Sonja Mülhopt 3, Hanns-Rudolf Paur 3, Iseult Lynch 5 , Eugenia Valsami-Jones 5 , Marie Carriere 2, and Carsten Weiss 1
1 Karlsruhe Institute of Technology, Institute of Biological and Chemical Systems–Biological Information Processing, 76344 Eggenstein-Leopoldshafen, Germany;
2 CEA, CNRS, IRIG, SyMMES, University Grenoble Alpes, 38054 Grenoble, France;
3 Karlsruhe Institute of Technology, Institute for Technical Chemistry, 76344 Eggenstein-Leopoldshafen, Germany;
4 Promethean Particles Ltd., Nottingham NG7 3EF, UK;
5 School of Geography Earth & Environmental Sciences (GEES), University of Birmingham (UoB), Edgbaston, Birmingham B15 2TT, UK;
KIT, together with VITROCELL SYSTEMS, set up a first Automated Exposure Station, which has been used for the assessment of nanoscale particle emissions from combustion sources such as ship diesel and wood burners. The system was further developed and offers a compact solution for toxicity testing of nanoparticle (NP) aerosols including sample conditioning, reproducible deposition, integrated dose determination by a quartz crystal microbalance (QCM), flow control, automated processes and data acquisition. The device was also tested with partner laboratories with the aim of potentially standardizing and achieving regulatory acceptance of the method.
Reliable and predictive in vitro assays for hazard assessments of manufactured nanomaterials (MNMs) are still limited. Specifically, exposure systems which more realistically recapitulate the physiological conditions in the lung are needed to predict pulmonary toxicity. To this end, air-liquid interface (ALI) systems have been developed in recent years which might be better suited than conventional submerged exposure assays. However, there is still a need for rigorous side-by-side comparisons of the results obtained with the two different exposure methods considering numerous parameters, such as different MNMs, cell culture models and read outs. In this study, human A549 lung epithelial cells and differentiated THP-1 macrophages were exposed under submerged conditions to two abundant types of MNMs i.e., ceria and titania nanoparticles (NPs). Membrane integrity, metabolic activity as well as pro-inflammatory responses were recorded. For comparison, A549 monocultures were also exposed at the ALI to the same MNMs. In the case of titania NPs, genotoxicity was also investigated. In general, cells were more sensitive at the ALI compared to under classical submerged conditions. Whereas ceria NPs triggered only moderate effects, titania NPs clearly initiated cytotoxicity, pro-inflammatory gene expression and genotoxicity. Interestingly, low doses of NPs deposited at the ALI were sufficient to drive adverse outcomes, as also documented in rodent experiments. Therefore, further development of ALI systems seems promising to refine, reduce or even replace acute pulmonary toxicity studies in animals.