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In this contribution, we present the spectroscopic study of two NIR emitting hydrophobic heteroleptic (R,R)-YbL1(tta) and (R,R)-NdL1(tta) complexes (with tta = 2-thenoyltrifluoroacetonate and L1 = N,N′-bis(2-(8-hydroxyquinolinate)methylidene)-1,2-(R,R or S,S)-cyclohexanediamine), both in methanol solution and embedded in water dispersible and biocompatible poly lactic-co-glycolic acid (PLGA) nanoparticles. Thanks to their absorption properties in a wide range of wavelengths extending from the UV up to the blue and green visible regions, the emission of these complexes can be effectively sensitized using visible radiation, which is much less harmful to tissues and skin than the UV one. The encapsulation of the two Ln(III)-based complexes in PLGA allows us to preserve their nature, making them stable in water and to test their cytotoxicity on two different cell lines, with the aim of using them in the future as potential bioimaging optical probes.

Heavy metals and Brominated diphenyl ether flame-retardants (BDEs) often coexist in the environment and are capable of inducing injury, cytotoxicity or genotoxicity in human epithelial cells of the lung. We studied the effects of single Cadmium chloride (CdCl2) or CdCl2/BDE (47 or 209) mixtures in airway epithelial cells, using A549 cell line cultured at submerged conditions and air–liquid interface (ALI) (an in vitro model described as physiologically relevant in vivo-like). We evaluated cell viability, oxidative stress, apoptosis, DNA damage/repair (Comet assay, γH2AX phosphorylation ser139), mitochondrial redox balance (NOX-4, Nrf2 and TFAM) and cell barrier integrity (TEER, ZO-1, Claudin-1, E-cadherin-1) in A549 cells exposed to CdCl2 (1 nM to 10 µM), or to CdCl2 (100 nM)/BDEs (47 or 209) (100 nM). CdCl2 (10 μM) reduced cell viability and increased apoptosis. CdCl2 (100 nM) significantly affected DNA-damage/repair (Olive Tail length production), γH2AX phosphorylation and oxidative stress (ROS/JC-1 production) in submerged cell cultures. CdCl2 (100 nM) decreased viability, TEER, ZO-1, Claudin-1 and E-cadherin-1 mRNA expression, and Nrf2 and TFAM while increased NOX-4, in ALI culture of cells. In both cell culture approaches, the cells stimulated with Cadmium/BDEs mixtures did not show a significant increase in the effects observed in the cells treated with CdCl2 alone. CdCl2 inhalation might exert cytotoxicity and genotoxicity, playing a pivotal role in the uncontrolled oxidative stress, damaging DNA and gene expression in airway epithelial cells. No additional or synergistic adverse effects of CdCl2/BDEs mixture were observed in comparison to CdCl2 alone in lung epithelium.

In the original article [...]

Abstract: Exposure to outdoor air pollution has been shown to increase asthma symptoms. We assessed the potential role of particulate matter with aerodynamic diameter 2.5) on respiratory condition in schoolchildren in the south Mediterranean area. A total of 2400 children aged 11–14 years were recruited, and data on their symptoms were collected through an ISAAC (International Study of Asthma and Allergies in Childhood)-based questionnaire. Outdoor PM2.5 was collected for 48 consecutive hours in the schoolyards of their schools and selected residential outdoor areas. The levels of PM2.5 were measured, along with its elemental composition. The incidence of an acute respiratory illness within the first 2 years of life was higher amongst Sicilian children when compared to Maltese children (29.7% vs. 13.5% respectively, p < 0.0001). Malta had a significantly higher prevalence of doctor‐diagnosed asthma, when compared to Sicily (18.0% Malta vs. 7.5% Sicily, p p < 0.0001) and use of asthma medication in the last 12 months (12.1% vs. 4.9%, p < 0.0001) were more frequent amongst Maltese children. Total median PM2.5 was 12.9 μg/m3 in Sicily and 17.9 μg/m3 in Malta. PM2.5 levels were highest in the Maltese urban town of Hamrun (23.6 μg/m3), while lowest in the rural Sicilian town of Niscemi (10.9 μg/m3, p < 0.0001). Hamrun also exhibited the highest levels of nickel, vanadium, lead, zinc, antimony, and manganese, whilst the Sicilian city of Gela had the highest levels of cadmium, and the highest level of PM2.5 when compared to rural Sicily. Elevated levels of PM2.5 were positively associated with the prevalence of doctor diagnosed asthma (odds ratio (OR) 1.05), current asthma (OR 1.06), and use of asthma medication (OR 1.06). All elements in PM2.5 showed increased OR for doctor diagnosed asthma, while higher concentrations of Cd and Mn were associated with higher prevalence of rhinitis.