The use of a complex tetra-culture alveolar model to study the toxicological effects of gold nanoparticles with different physicochemical properties

Purpose: In the last decades, the advancements of nanotechnologies lead to a massive increase of engineered nanoparticles in consumer products, which translates in an increased human and environmental exposure to nanomaterials. For humans, inhalation is considered as the main exposure route to nanomaterials, which is the reason why lung toxicity studies should be considered as a priority. Inhalation studies are often performed in vivo in rodents. Therefore, in vitro models may represent a valid and efficient alternative to predict the acute toxicity effects of inhaled NPs on human health. The model used in this study represents the human alveolar barrier; it is constituted by four different human pulmonary cell lines (EA.hy 296 on the basolateral side; A549, HMC-1 and macrophage-like cells in the apical side). The cells in the apical side were cultivated at the air-liquid-interface (ALI) and they have been exposed to AuNPs with the VitroCell® Cloud System. Results: We describe the effects after 24 hours of exposure to three different gold nanoparticles (AuNPs) in order to evaluate the suitability of our model to assess the toxicological effects of particles. The set of PEGylated AuNPs used included spheres (GNPs), rods (GNRs) and stars (GNSs). The exposure did not cause any significant decrease of viability; all the AuNPs caused cytotoxicity and increase of IL-8 levels at the highest dose. The AuNP were up-taken by the cells in the apical side and they also translocated in the basolateral side. Regarding the global transcript, among differentially expressed genes (DEG) were found genes related to the enhancement of immune cells. Conclusion: AuNPs in the used range of concentrations did not cause severe effects on the co-culture, but different effects were observed for the different types of AuNPs supporting the role of the physico-chemical NP parameters in NP-cell interactions. In addition, our model resulted perfectly suitable to investigate the biological effects of particles especially in terms of inflammatory response and translocation. Overall design: Epithelial and endothelial mRNA profiles of 24h exposed complex lung alveoli in vitro models to 3 different type of Au NPs in comparison to a negative control all in three biological replicates.