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Thermal waters near the city of Viterbo (Central Italy) are known to show high As contents (up to 600 µg/l). Travertine is precipitated by these waters, forming extended plateau. In this study, we determine the As content, speciation and bioaccessibility in soil and travertine samples collected near a recreational area highly frequented by local inhabitants and tourists to investigate the risk of As exposure through accidental ingestion of soil particles. (Pseudo)total contents in the studied soils range from 17 to 528 mg/kg, being higher in soil developed on a travertine substrate (197 ± 127 mg/kg) than on volcanic rocks (37 ± 13 mg/kg). In travertines, most As is bound to the carbonatic fraction, whereas in soil the semimetal is mostly associated with the oxide and residual fractions. Accordingly, bioaccessibility (defined here by the simplified bioaccessibility extraction test, SBET; Oomen et al., 2002.) is maximum (up to 139 mg/kg) for soil developed on a travertine substrate, indicating a control of calcite dissolution on As bioaccessibility. On the other hand, risk analysis suggests a moderate carcinogenic risk associated with accidental soil ingestion, while dermal contact is negligible. By contrast, ingestion of thermal water implies a higher carcinogenic and systemic health risk.

Two new hydrated bismuth sulfates have been discovered on a bismuth mineralization associated with quartziferous dikes intruding Pre-Triassic orthogneiss and garnet micaschist from Alfenza (Crodo), Antigorio Valley, Italian Alps (Capitani et al. 2011). The new minerals are found in “hortensia-like” aggregates of white, micrometre-sized crystallites or massive incrustations covering bismuthinite and quartz. At the SEM, they appear constituted of ~20 microns wide, few micron thick, randomly oriented, hexagonal platelets. EDS semi-quantitative analyses lead to the simplified chemical formula [Bi2SO4(OH)4]. IR spectroscopy confirms the presence of hydroxyls and the absence of water molecules. Due to the very small amount of material and the very small size of each crystallite, no X-ray diffraction analysis has been possible so far. On the contrary, transmission electron microscopy and diffraction, performed either by conventional zone orientation and automated diffraction tomography (Kolb et al 2007), reveals two distinct phases, both without any natural or synthetic analogue; one phase is monoclinic, with a = 17.2(4), b = 15.9(3), c = 20.3(4) Å, beta = 95(1), and P21 or P21/m symmetry; the other phase is hexagonal, with a = 9.6(2), c = 15.3(3) Å, and P¯62c symmetry. The two phases can be recognized at the TEM not only by their unit cell geometry and symmetry, but also by their morphology and different beam sensitivity, whereas they are compositionally identical within the experimental error. The monoclinic phase has perfect basal cleavage that make its recognizable as (001) oriented platelets on TEM grids, show a strong diffuse scattering along the c* direction, and is very beam sensitive. The hexagonal phase is more resistant under the electron beam and does not show any preferential cleaving orientation. By morphological similarity, we draw the conclusion that the first phase is representative of the hexagonal platelets, while it was not possible to unambiguously associate the second phase with a specific morphology in SEM images. Structure solution for both the phases has been attempted on the basis of automated diffraction tomography data. The orthorhombic phase, since beam sensitive and affected by stacking disorder, gave only partial results. On the contrary, the hexagonal phase gave a sound and reproducible structure. This new phase is built up by laterally offset, stacked pairs of Bi3O3 (001) ditrigonal rings, capped by SO4 tetrahedra, interleaved and further cemented by additional (001) BiO layers.

Samples of summer and winter (2010-2011) atmospheric particulate (PM10) of Milan urban area were collected and characterized for some classes of components with health impact. Moreover, the PM chemical characterization of the main components (i.e. inorganic compounds, organic compounds, and elemental carbon) was performed by XRF and ICP-MS. Toxicity test on pulmonary immortalized cell lines showed different effects produced by summer and winter samples. Indeed, the summer PM10 fraction has a more pronounced inflammatory effect, due to the presence of endotoxins. Nevertheless, their inhibition did not completely vanish the inflammatory effect, which may be related also to both sialic material of crustal source and transition metals . The amount of such materials is significantly higher in the summer PM10. The morphology and chemistry of this fraction components were characterized by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX). Further analytical transmission electron microscopy (ATEM) investigation will allow to discriminate the mineralogical phases that contribute to the PM10 silicon and transition elements.

Quantum dot solar cells are based on the concept of harvesting different parts of the solar light spectrum with a single, cheap semiconductor by simply changing the size of the nanoparticles. Of the many compositions explored, germanium is one of the most interesting as it has the major advantage of a large Bohr radius, which allows for the fabrication of larger particles. Moreover, germaniums possess very high optical absorption, and a small band gap give it free parameters to optimize the quantum dot solar cell. In a previous work, the germanium quantum dots were used in a Gratzel type solar cell containing an electrolyte, which is not desirable for applications. In this work instead, the n-doped germanium quantum dots were combined with a p-doped a-Si layer, making it the first all solid-state solar cell made from nanoparticles from a gas aggregation nanoparticle source. Remarkably, the effect of quantum confinement in both the germanium quantum dot assembled layer and a-Si was observed by peaks in the spectral response experiments. This work forms an important step toward realizing a germanium quantum dot based solar cell and studying quantum dot based solids.

Broadly used in biocatalysis as acyl acceptors or (co)-solvents, short-chain alcohols often cause irreversible loss of enzyme activity. Understanding the mechanisms of inactivation is a necessary step toward the optimization of biocatalytic reactions and the design of enzyme-based sustainable processes. The functional and structural responses of an immobilized enzyme, Novozym 435 (N-435), exposed to methanol, ethanol, and tert-butanol, are explored in this work. N-435 consists of Candida antarctica lipase B (CALB) adsorbed on polymethacrylate beads and finds application in a variety of processes involving the presence of short-chain alcohols. The nature of the N-435 material required the development of an ad hoc method of structural analysis, based on Fourier transform infrared microspectroscopy, which was complemented by catalytic activity assays and by morphological observation by transmission electron microscopy. The inactivation of N-435 was found to be highly dependent on alcohol concentration and occurs through two different mechanisms. Short-chain alcohols induce conformational changes leading to CALB aggregation, which is only partially prevented by immobilization. Moreover, alcohol modifies the texture of the solid support promoting the enzyme release. Overall, knowledge of the molecular mechanisms underlying N-435 inactivation induced by short-chain alcohols promises to overcome the limitations that usually occur during industrial processes.

Multidrug antimicrobial resistance is a constantly growing health care issue associated with increased mortality and morbidity, and huge financial burden. Bacteria frequently form biofilm communities responsible for numerous persistent infections resistant to conventional antibiotics. Herein, novel nanoparticles (NPs) loaded with the natural bactericide farnesol (FSL NPs) are generated using high-intensity ultrasound. The nanoformulation of farnesol improved its antibacterial properties and demonstrated complete eradication of Staphylococcus aureus within less than 3 h, without inducing resistance development, and was able to 100% inhibit the establishment of a drug-resistant S. aureus biofilm. These antibiotic-free nano-antimicrobials also reduced the mature biofilm at a very low concentration of the active agent. In addition to the outstanding antibacterial properties, the engineered nano-entities demonstrated strong antiviral properties and inhibited the spike proteins of SARS-CoV-2 by up to 83%. The novel FSL NPs did not cause skin tissue irritation and did not induce the secretion of anti-inflammatory cytokines in a 3D skin tissue model. These results support the potential of these bio-based nano-actives to replace the existing antibiotics and they may be used for the development of topical pharmaceutic products for controlling microbial skin infections, without inducing resistance development.

Microplastic pollution represents a global problem with negative impacts on aquatic environment and organisms' health. To date, most of the laboratory toxicological studies on microplastics (MPs) have made use of single commercial micro and nano-polymers, which do not reflect the heterogeneity of environmental MPs. To improve the relevance of the hazard assessment, micrometer-sized plastic particles of miscellaneous non-reusable waste plastics, with size

In the biomedical field, gold nanoparticles (GNPs) have attracted the attention of the scientific community thanks to their high potential in both diagnostic and therapeutic applications. The extensive use of GNPs led researchers to investigate their toxicity, identifying stability, size, shape, and surface charge as key properties determining their impact on biological systems, with possible strategies defined to reduce it according to a Safe-by-Design (SbD) approach. The purpose of the present work was to analyze the toxicity of GNPs of various sizes and with different coating polymers on the developing vertebrate model, zebrafish. In particular, increasing concentrations (from 0.001 to 1 nM) of 6 or 15 nm poly-(isobutylene-alt-maleic anhydride)-graft-dodecyl polymer (PMA)- or polyethylene glycol (PEG)-coated GNPs were tested on zebrafish embryos using the fish embryo test (FET). While GNP@PMA did not exert significant toxicity on zebrafish embryos, GNP@PEG induced a significant inhibition of embryo viability, a delay of hatching (with the smaller size NPs), and a higher incidence of malformations, in terms of tail morphology and eye development. Transmission electron microscope analysis evidenced that the more negatively charged GNP@PMA was sequestered by the positive charges of chorion proteins, with a consequent reduction in the amount of NPs able to reach the developing embryo and exert toxicological activity. The mild toxic response observed on embryos directly exposed to GNP@PMA suggest that these NPs are promising in terms of SbD development of gold-based biomedical nanodevices. On the other hand, the almost neutral GNP@PEG, which did not interact with the chorion surface and was free to cross chorion pores, significantly impacted the developing zebrafish. The present study raises concerns about the safety of PEGylated gold nanoparticles and contributes to the debated issue of the free use of this nanotool in medicine and nano-biotechnologies.

Innate immune responses to Gram-negative bacteria depend on the recognition of lipopolysaccharide (LPS) by a receptor complex that includes CD14 and TLR4. In dendritic cells (DCs), CD14 enhances the activation not only of TLR4 but also that of the NFAT family of transcription factors, which suppresses cell survival and promotes the production of inflammatory mediators. NFAT activation requires Ca2+ mobilization. In DCs, Ca2+ mobilization in response to LPS depends on phospholipase C γ2 (PLCγ2), which produces inositol 1,4,5-trisphosphate (IP3). Here, we showed that the IP3 receptor 3 (IP3R3) and ITPKB, a kinase that converts IP3 to inositol 1,3,4,5-tetrakisphosphate (IP4), were both necessary for Ca2+ mobilization and NFAT activation in mouse and human DCs. A pool of IP3R3 was located on the plasma membrane of DCs, where it colocalized with CD14 and ITPKB. Upon LPS binding to CD14, ITPKB was required for Ca2+ mobilization through plasma membrane-localized IP3R3 and for NFAT nuclear translocation. Pharmacological inhibition of ITPKB in mice reduced both LPS-induced tissue swelling and the severity of inflammatory arthritis to a similar extent as that induced by the inhibition of NFAT using nanoparticles that delivered an NFAT-inhibiting peptide specifically to phagocytic cells. Our results suggest that ITPKB may represent a promising target for anti-inflammatory therapies that aim to inhibit specific DC functions.

Amyloid aggregation of human ataxin-3 (ATX3) is responsible for spinocerebellar ataxia type 3, which belongs to the class of polyglutamine neurodegenerative disorders. It is widely accepted that the formation of toxic oligomeric species is primarily involved in the onset of the disease. For this reason, to understand the mechanisms underlying toxicity, we expressed both a physiological (ATX3-Q24) and a pathological ATX3 variant (ATX3-Q55) in a simplified cellular model, Escherichia coli. It has been observed that ATX3-Q55 expression induces a higher reduction of the cell growth compared to ATX3-Q24, due to the bacteriostatic effect of the toxic oligomeric species. Furthermore, the Fourier transform infrared microspectroscopy investigation, supported by multivariate analysis, made it possible to monitor protein aggregation and the induced cell perturbations in intact cells. In particular, it has been found that the toxic oligomeric species associated with the expression of ATX3-Q55 are responsible for the main spectral changes, ascribable mainly to the cell envelope modifications. A structural alteration of the membrane detected through electron microscopy analysis in the strain expressing the pathological form supports the spectroscopic results.

Incomplete combustion processes in diesel engines produce particulate matter (PM) that significantly contributes to air pollution. Currently, there remains a knowledge gap in relation to the physical and chemical characteristics and also the biological reactivity of the PM emitted from old- and new-generation diesel vehicles. In this study, the emissions from a Euro 3 diesel vehicle were compared to those from a Euro 6 car during the regeneration of a diesel particulate filter (DPF). Different driving cycles were used to collect two types of diesel exhaust particles (DEPs). The particle size distribution was monitored using an engine exhaust particle sizer spectrometer and an electrical low-pressure impactor. Although the Euro 6 vehicle emitted particulates only during DPF regeneration that primarily occurs for a few minutes at high speeds, such emissions are characterized by a higher number of ultrafine particles (

Macrophage inflammation and maturation into foam cells, following the engulfment of oxidized low-density lipoproteins (oxLDL), are major hallmarks in the onset and progression of atherosclerosis. Yet, chronic treatments with anti-inflammatory agents, such as methotrexate (MTX), failed to modulate disease progression, possibly for the limited drug bioavailability and plaque deposition. Here, MTX-lipid conjugates, based on 1,2-distearoyl-sn-glycero-3-phosphoethanolamine (DSPE), were integrated in the structure of spherical polymeric nanoparticles (MTX-SPN) or intercalated in the lipid bi-layer of liposomes (MTX-LIP). Although, both nanoparticles were colloidally stable with an average diameter of ∼ 200 nm, MTX-LIP exhibited a higher encapsulation efficiency (> 70%) and slower release rate (∼50% at 10h) compared to MTX-SPN. In primary bone marrow derived macrophages (BMDM), MTX-LIP modulated the transcellular transport of oxLDL more efficiently than free MTX mostly by inducing a 2-fold overexpression of ABCA1 (regulating oxLDL efflux); while the effect on CD36 and SRA-1 (regulating oxLDL influx) was minimal. Furthermore, in BMDM, MTX-LIP showed a stronger anti-inflammatory activity than free MTX reducing the expression of IL-1β by 3-fold, IL-6 by 2-fold and also moderately of TNF-α. In 28 days high-fat-diet fed apoE-/- mice, MTX-LIP reduced the mean plaque area by 2-fold and the hematic amounts of RANTES by half as compared to free MTX. These results would suggest that the nano-enhanced delivery to vascular plaques of the anti-inflammatory DSPE-MTX conjugate could effectively modulate the disease progression by halting monocytes’ maturation and recruitment already at the onset of atherosclerosis.

Airborne ultrafine particles (UFP) mainly derive from combustion sources (e.g., diesel exhaust particles&mdash, DEP), abrasion sources (non-exhaust particles) or from the unintentional release of engineered nanoparticles (e.g., metal oxide nanoparticles&mdash, NPs), determining human exposure to UFP mixtures. The aim of the present study was to analyse the combined in vitro effects of DEP and metal oxide NPs (ZnO, CuO) on human lung A549 cells. The mixtures and the relative single NPs (DEP, ZnO, CuO) were characterized by transmission electron microscopy (TEM), dynamic light scattering (DLS) and inductively coupled plasma-optic emission spectroscopy (ICP-OES). Cells were exposed for different times (3&ndash, 72 h) to mixtures of standard DEP at a subcytotoxic concentration and ZnO and CuO at increasing concentrations. At the end of the exposure, the cytotoxicity was assessed by 3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide (MTT) and clonogenic tests, the pro-inflammatory potential was evaluated by interleukin-8 (IL-8) release and the cell morphology was investigated by fluorescence and transmission electron microscopy. The obtained results suggest that the presence of DEP may introduce new physico-chemical interactions able to increase the cytotoxicity of ZnO and to reduce that of CuO NPs.

Most of the atmospheric ultrafine particles (UFPs) in urban areas derive from combustion sources, especially diesel exhaust particles (DEP), but also from non-exhaust sources or from the unintentional release of engineered nanoparticles (NPs) during production and use. Since the environmental exposure to DEP and NPs occur simultaneously, it is necessary to consider their possible interactive effects in biological system. Commercially available (cZnO, cCuO

Among nano metal oxides, Zn-doped CuO nanocomposite (nZn-CuO) showed antibacterial activity more effective than nZnO or CuO nanoparticles, due to higher ROS production. Hence, nZn-CuO is considered a promising nanotool for coating different materials, including reverse osmosis membranes for water purification, to confer antibacterial properties. However, the effects of nZn-CuO on water purification membranes to the aquatic ecosystem health, when released into the aquatic environment, are still unknown. Consequently, this work aim is to define: 1) the eventual release of nZn-CuO in water and 2) the toxicological potential of nZn-CuO functionalized membranes on aquatic organisms. Zebrafish (Danio rerio) is widely accepted as a model for ecotoxicological studies. Organisation for Economic Co-operation and Development (OECD) recommends the Fish Embryo Acute Toxicity (FET) test (OECD n. 236) to determine toxicity of a wide variety of chemicals on zebrafish embryonic stages. Fertilized eggs are exposed to chemicals for 96 hours and different morphological indicators of lethality are recorded every 24 hours. At the end of the exposure, acute toxicity is determined based on a positive outcome in any of the observations recorded. During FET test, nZn-CuO affects zebrafish hatching and this effect likely would have an impact on development at later phases. Therefore, FET test is considered a powerful tool to evaluate Zn-doped CuO nanocomposite and reverse osmosis leachate toxicological potential in aquatic environment. Further investigations are necessary to better comprehend the real potential of nZn-CuO as an antibacterial coating for reverse osmosis membrane. Moreover, biomarkers of sublethal effect will be evaluated.

Diesel exhaust particles (DEPs) and non-exhaust particles from abrasion are two main representative sources of air pollution to which humans are exposed daily, together with emerging nanomaterials, whose emission is increasing considerably. In the present work, we aimed to investigate whether DEPs, metal oxide nanoparticles (MeO-NPs), and their mixtures could affect alveolar cells. The research was focused on whether NPs induced different types of death in cells, and on their effects on cell motility and migration. Autophagy and cell cycles were investigated via cytofluorimetric analyses, through the quantification of the autophagic biomarker LC3B and PI staining, respectively. Cellular ultrastructures were then observed via TEM. Changes in cell motility and migration were assessed via transwell migration assay, and by the cytofluorimetric analysis of E-cadherin expression. A colony-forming efficiency (CFE) assay was performed in order to investigate the interactions between cells inside the colonies, and to see how these interactions change after exposure to the single particles or their mixtures. The results obtained suggest that NPs can either reduce the toxicity of DEPs (CuO) or enhance it (ZnO), through a mechanism that may involve autophagy as cells’ response to stressors and as a consequence of particles’ cellular uptake. Moreover, NPs can induce modification of E-cadherin expression and, consequentially, of colonies’ phenotypes.

It is commonly accepted that the toxicity of carbonaceous particulate matter (PM) is due to the production of reactive oxygen species (ROS) which induce biological damage in the exposed cells. It is also known that PM produced during the combustion processes consists of a carbonaceous core "dressed" with other organic and/or inorganic materials. In spite of this knowledge, the role of these materials in the production of ROS has not yet been clear. This work aims at understanding whether "naked" carbonaceous particles are capable of forming ROS either in cell-free or in-cell systems. The problem has been treated based on the data collected from pure graphite samples of different sizes obtained by ball-milling pure graphite for various lengths of time. The experimental approach considered Raman, ESR (spin trapping), cell viability and fluorescence spectroscopy measurements. These techniques allowed us to carry out measurements both in cell and cell-free systems and the results consistently indicate that also pure naked carbonaceous particles can catalyze the electron transfer that produces superoxide ions. The process depends on the particle size and enlightens the role of the edges of the graphitic platelets. Evidence has been collected that even "naked" graphitic nanoparticles are capable of producing ROS and decreasing the cell viability thus representing a potential danger to human health. © 2017 The Royal Society of Chemistry.

Canonite from Alfenza grows as crowded, radiating, acicular aggregates covering bismuthinite crystals. Individual crystals have a lozenge-shaped habit on {010}, the presumed cleavage plane of cannonite. Crystal structure refinements in the P21/c space group of two single crystals led to the following cell parameters: a = 7.7196(5) Å, b = 13.8856(9), c = 5.6980(4), b = 109.174(1)º (R1 = 0.0424); and a = 7.7100(8), b = 13.8717(14), c = 5.6939(6), b = 109.155(2)º (R1 = 0.0438). Hydrogen atoms were also localized in the density-difference Fourier map and refined with soft restraints on the bond distances. Raman and IR spectroscopy confirm the presence of OH groups and the absence of molecular water, and deliver OH···O geometry wholly comparable with the structure refinement. Electron microprobe analyses revealed no significant levels of elements other than those expected in the ideal formula except fluorine which was present up to 0.14 a.p.f.u. The crystal structure can be described in terms of anion-centred OBi4 edge-sharing tetrahedra forming chains running parallel to z and strongly cemented along x by isolated SO4 tetrahedra. Each OBi4 tetrahedron is further connected along y by OH groups, making walls of composition Bi4O2(SO4)2(OH)4 parallel to (010). These walls are tied to each other along y by fewer Bi–O–S bridges and weaker OH···O bonds.

Air pollution mostly originating from car exhaust and industrial emissions is seriously endangering human health. The study of toxic effects of particulate matter (PM) is a subject of very active research that covers a broad field from biology to chemistry and technology. The main issue of these works is the understanding of the oxidative properties of PM. In this paper, we present a quantitative analytical method based on the resonance Raman spectroscopy of cytocrome c that can be used to monitor the oxidative reactions that may take place between biological samples and PM. Air pollution mostly originating from car exhaust and industrial emissions is seriously endangering human health. The study of toxic effects of particulate matter (PM) is a subject of very active research that covers a broad field from biology to chemistry and technology. The main issue of these works is the understanding of the oxidative properties of PM. In this paper, we present a quantitative analytical method based on the resonance Raman spectroscopy of cytocrome c that can be used to monitor the oxidative reactions that may take place between biological samples and PM.

We report about three bismuth sulfates from mineralized quartz dikes from Alfenza (Crodo, Italy), two new phases and a rare mineral, cannonite, all growing on bismuthinite. The first new phase occurs as white, "hortensia-like" aggregates of pseudo-hexagonal platelets, with perfect basal cleavage, similar to 20 mu m wide and few micrometers thick. The approximate composition is Bi2O2(SO4), and cell parameters and symmetry, as determined by automatic diffraction tomography, are a = 22.0(4), b = 16.7(3), c = 15.9(3) angstrom, beta = 102.9(5)degrees, space group Pc or P2/c. A major stacking disorder is detected by HR-SEM images and electron diffraction data.The second new phase was detected only by TEM. It can be distinguished by its random orientation on the TEM grid (i.e., absence of preferential parting), the higher resistance under the electron beam, and different cell parameters and structure, whereas the composition is similar (Bi/S similar to 2.2/1), apart for the presence of tellurium up to similar to 6 cations percents. The unit cell is hexagonal, space group P (6) over bar 2c, a = 9.5(2) and c = 15.4(3) angstrom. In this case, a structure model was obtained ab initio from electron diffraction data. Interestingly, the mineral has a porous structure with one dimensional porosity (diameter of the channel similar to 7 angstrom).Finally, within the same centimeter sized hand-specimens, we detected also cannonite. Its identification was done by automatic diffraction tomography. The measured cell parameters are a = 7.7(2), b = 13.9(3), c = 5.7(1) angstrom, beta = 109.8(5)degrees, the space group P2(1)/c. Cannonite at Alfenza forms radiating, acicular aggregates of colorless, transparent crystals with "scalpel-like" habit, elongated along c, up to 200 mu m in length.