Leveraging proteomics to compare submerged versus air-liquid interface carbon nanotube exposure to a 3D lung cell model.

With the emerging concern over the potential toxicity associated with carbon nanotube inhalation exposure, several in vitro methods have been developed to evaluate cellular responses. Since the major concern for adverse effects by carbon nanotubes is inhalation, various lung cell culture models have been established for toxicity testing, thus creating a wide variation of methodology. Limited studies have conducted side-by-side comparisons of common methods used for carbon nanotube hazard testing. The aim of this work was to use proteomics to evaluate global cellular response, including pro-inflammatory and pro-fibrotic mediators, of a 3D lung model composed of macrophages, epithelial cells, and fibroblasts which mimics the human alveolar epithelial tissue barrier. The cells were exposed to Mitsui 7 (M-7) multi-walled carbon nanotubes (MWCNT) under submerged and air-liquid interface (ALI) conditions and discovery proteomics identified 3500 proteins. The M-7 ALI exposure compared to control was found to increase expression in proteins related to oxidative stress that were not found to be enriched in submerged exposure. Comparison of MWCNT exposure methods, M-7 ALI exposure versus M-7 submerged exposure, yielded protein enrichment in pathways known to be associated with carbon nanotube exposure stress response, such as acute phase response signaling and NRF2-mediated oxidative stress response. This study demonstrates a comparison of commonly deployed carbon nanotube exposure methods. These data should be considered by the nanotoxicology community when interpreting or cross comparing in vitro exposure results.

Metal-based particles in human amniotic fluids of fetuses with normal karyotype and congenital malformation--a pilot study.

This study explores the inorganic composition of amniotic fluid in healthy human fetuses and fetuses with congenital malformation with a special attention to presence of metal-based solid particles. Amniotic fluid originates from maternal blood and provides fetus mechanical protection and nutrients. In spite of this crucial role, the environmental impact on the composition of amniotic fluid remains poorly studied. The samples of human amniotic fluids were obtained by amniocentesis, including both healthy pregnancies and those with congenital malformations. The samples were analysed using several techniques, including Raman microspectroscopy, scanning electron microscopy with energy-dispersed spectrometry (SEM-EDS), Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) analysis. Several metal-based particles containing barium, titanium, iron, and other elements were detected by SEM-EDS and Raman microspectroscopy. XRD analysis detected only sodium chloride as the main component of all amniotic fluid samples. Infrared spectroscopy detected protein-like organic components. Majority of particles were in form of agglomerates up to tens of micrometres in size, consisting of mainly submicron particles. By statistical analysis (multiple correspondence analysis), it was observed that groups of healthy and diagnosed fetuses form two separate groups and therefore, qualitative differences in chemical composition may have distinct biological impact. Overall, our results suggest that metal-based nanosized pollutants penetrate into the amniotic fluid and may affect human fetuses.