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- Assessing the impact of TiO2 nanomaterials on intestinal cells: New evidence for epithelial translocation and potential pro-inflammatory effectsPublication . Rolo, Dora; Pereira, Joana F.S.; Gonçalves, Lídia; Bettencourt, Ana; Jordan, Peter; Silva, Maria João; Matos, Paulo; Louro, HenriquetaUnderstanding the potential impact of nanomaterials (NMs) on human health requires further investigation into the organ-specific nano-bio interplay at the cellular and molecular levels. We showed increased chromosomal damage in intestinal cells exposed to some of in vitro digested Titanium dioxide (TiO2) NMs. The present study aimed to explore possible mechanisms linked to the uptake, epithelial barrier integrity, cellular trafficking, as well as activation of pro-inflammatory pathways, after exposure to three TiO2-NMs (NM-102, NM-103, and NM-105). Using confocal microscopy, we show that all NMs, digested or not, were able to enter different types of intestinal cells. At the physiologically relevant concentration of 14 μg/mL, the digested TiO2-NMs did not compromise the transepithelial resistance, nor the levels of epithelial markers E-cadherin and Zonula occludens protein 1 (ZO-1), of polarized enterocyte monolayers. Nonetheless, all NMs were internalized by intestinal cells and, while NM-102 was retained in lysosomes, NM-103 and NM-105 were able to transverse the epithelial barrier through transcytosis. Moreover, 24 h exposure of 14 and 1.4 μg/mL digested NM-105, promoted interleukin IL-1β expression in activated M1 macrophages, indicating a potential pro-inflammatory action in the gut. Taken together, our findings shed light on the cell-specific nano-bio interplay of TiO2-NMs in the context of the intestinal tract and highlight transcytosis as a potential gateway for their systemic distribution. The potential proinflammatory action of digested NM-105 emphasizes the importance of pursuing research into the potential impact of NMs on human health and contribute to the weight of evidence to limit their use in food.
- Incidental nanoparticle characterisation in industrial settings to support risk assessment modellingPublication . Moreno-Martín, Veronica; López, Maria; Bou, David; Fraga, Sónia; Teixeira, João Paulo; López-Lilao, Ana; Sanfélix, Vicenta; Monfort, Eliseo; Viana, MarResearch on nanoparticle (NP) release and potential exposure can be assessed through experimental field campaigns, laboratory simulations, and prediction models. However, risk assessment models are typically designed for manufactured NP (MNP) and have not been adapted for incidental NP (INP) properties. A notable research gap is identifying NP sources and their chemical, physical, and toxicological properties, especially in real-world settings. This work aims to provide insights into the release and physico-chemical properties of INP while contributing to improving models for INP release. INP release was evaluated through a case study in a ceramic tile firing facility, where aerosol (10 nm - 10 μm) properties were determined. The Control Banding (CB) Nanotool model was applied to test outputs based on provided input parameters. Results: demonstrate the constant generation and release of INP during tile firing, with NP concentrations up to 68711/cm³ and mean diameters of 37 nm, with 95% smaller than 100 nm. Particle morphology was mostly spherical, suggesting nucleation from precursor gases as the main formation mechanism. INP chemical composition was driven by primary ceramic components, while trace elements like Ni and Ti exhibited sizedependent patterns. In vitro cell viability tests indicated low to medium cytotoxicity of PM2 aerosols, decreasing human alveolar epithelial cell viability in a concentration-dependent manner. Applying the risk model with varying input parameters revealed that the risk level (RL) based on severity scores decreased when aerosol size distribution data were used, illustrating the model’s sensitivity to input variables. We conclude on the need for comprehensive experimental datasets to support risk assessment models and achieve effective risk management strategies in real-world scenarios.