Article

A newly developed in vitro model of the human epithelial airway barrier to study the toxic potential of nanoparticles

Institute of Anatomy, Division of Histology, University of Bern, Bern, Switzerland.
ALTEX 02/2008; 25(3):191-6.
Source: PubMed

ABSTRACT The potential health effects of inhaled engineered nanoparticles are almost unknown. To avoid and replace toxicity studies with animals, a triple cell co-culture system composed of epithelial cells, macrophages and dendritic cells was established, which simulates the most important barrier functions of the epithelial airway. Using this model, the toxic potential of titanium dioxide was assessed by measuring the production of reactive oxygen species and the release of tumour necrosis factor alpha. The intracellular localisation of titanium dioxide nanoparticles was analyzed by energy filtering transmission electron microscopy. Titanium dioxide nanoparticles were detected as single particles without membranes and in membrane-bound agglomerates. Cells incubated with titanium dioxide particles showed an elevated production of reactive oxygen species but no increase of the release of tumour necrosis factor alpha. Our in vitro model of the epithelial airway barrier offers a valuable tool to study the interaction of particles with lung cells at a nanostructural level and to investigate the toxic potential of nanoparticles.

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    • "Therefore, the purpose of this study was to develop a 3D intestinal co-culture model composed of cell lines, which mimics healthy and diseased conditions and is suitable to assess NP-cell interactions. Co-culture models have been widely accepted (Rothen- Rutishauser et al., 2005, 2008) and used in several studies, e.g. to evaluate NP toxicity when exposed to the lungs by inhalation (Muller et al., 2010; Rothen-Rutishauser et al., 2008). Regarding the intestinal epithelium, i.e. after oral ingestion, most of the models focus on co-cultures to study absorption, particle celltranslocation or particle-mucus interaction (Schimpel et al., 2014). "
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    ABSTRACT: Abstract Oral exposure to nanomaterials is a current concern, asking for innovative biological test systems to assess their safety, especially also in conditions of inflammatory disorders. Aim of this study was to develop a 3D intestinal model, consisting of Caco-2 cells and two human immune cell lines, suitable to assess nanomaterial toxicity, in either healthy or diseased conditions. Human macrophages (THP-1) and human dendritic cells (MUTZ-3) were embedded in a collagen scaffold and seeded on the apical side of transwell inserts. Caco-2 cells were seeded on top of this layer, forming a 3D model of the intestinal mucosa. Toxicity of engineered nanoparticles (NM101 TiO2, NM300 Ag, Au) was evaluated in non-inflamed and inflamed co-cultures, and also compared to non-inflamed Caco-2 monocultures. Inflammation was elicited by IL-1β, and interactions with engineered NPs were addressed by different endpoints. The 3D co-culture showed well preserved ultrastructure and significant barrier properties. Ag NPs were found to be more toxic than TiO2 or Au NPs. But once inflamed with IL-1β, the co-cultures released higher amounts of IL-8 compared to Caco-2 monocultures. However, the cytotoxicity of Ag NPs was higher in Caco-2 monocultures than in 3D co-cultures. The naturally higher IL-8 production in the co-cultures was enhanced even further by the Ag NPs. This study shows that it is possible to mimic inflamed conditions in a 3D co-culture model of the intestinal mucosa. The fact that it is based on three easily available human cell lines makes this model valuable to study the safety of nanomaterials in the context of inflammation.
    Nanotoxicology 03/2015; DOI:10.3109/17435390.2015.1008065 · 7.34 Impact Factor
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    • "After the triple cell coculture was established, cell densities of macrophages and dendritic cells within the culture were quantified using the specific surface markers CD14 and CD86 for the labeling of macrophages and dendritic cells, respectively, and the quantitative occurrence of macrophages and dendritic cells resembled very closely the in-vivo situation (Blank et al., 2007). After its thorough evaluation, this model was exposed to particles (either airborne or suspended in medium) of different materials (polystyrene, titanium dioxide and gold) and of different sizes ( r1 mm) (Blank et al., 2007; Rothen- Rutishauser, 2007; Rothen-Rutishauser et al., 2008b; Brandenberger et al., 2010). Translocation and cellular localization of particles were studied as well as the effects of particles on cellular interplay and signaling. "
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