TY - JOUR AB - BACKGROUND: Multiple effects of ultrafine particles (UFP) on human subjects are known but there is less knowledge of how relative exposure levels between ultrafine and fine particles as typically encountered in large cities affect lung function and cardiovascular parameters. METHODS: Four sites with high/low levels of ultrafine particles and/or fine particles were selected in the city of Munich, Germany: control area (woodland), urban environment, heavy traffic site, biomass combustion (beech wood). In a randomized cross-over design, 26 young, healthy individuals were exposed at each site over 75 min to atmospheric pollutants, which were monitored continuously, while performing intermittent (5 min per 15 min) light exercise. Parameters assessed pre and post exposure comprised symptoms, spirometry, lung diffusing capacity for carbon monoxide (DLCO) and nitric oxide (DLNO), alveolar volume (AV), the fractional concentration of exhaled nitric oxide (FeNO), reactive hyperemia index (RHI), blood pressure, and heart rate. Outcomes were expressed as percent changes of parameters and analyses performed by either comparing the four sites or by multiple linear regression analyses using the measured pollutant levels. RESULTS: The sites showed the planned pattern of exposure levels but with large overlap. Outcomes showed no statistically significant differences between sites, except for symptoms which were elevated with heavy traffic site exposure and biomass combustion. In regression analyses, AV decreased by 0.92 (95% confidence interval (CI): 0.28 to 1.57) % per 10,000/cm3 UFP; similarly, for LDSA (lung-deposited surface area), which was highly correlated with UFP. Overall, FeNO slightly increased after exposure, but this increase was attenuated by 5.4 (95% CI: 1.8 to 9.2) % per 10 ppb ambient NO2. Heart rate decreased after exposures overall; this decrease was enhanced by 2.1 (95% CI: 0.3 to 4.0) % per 10,000/cm3 UFP. CONCLUSIONS: Short-term exposures to UFP elicited a reduction in the lung volume (AV) accessible to gas transport by diffusion and convection. FeNO was slightly elevated after all exposures, but this increase was significantly smaller at higher ambient NO2 concentrations. While these effects were too small to be clinically relevant, they demonstrated that typical levels of urban air pollution had measurable acute effects in young, healthy individuals. AU - Folwarczny, E.* AU - Förster, F.* AU - Jörres, R.A.* AU - Rakete, S.* AU - Ye, S.* AU - Wenig, M.* AU - Gawlitta, N. AU - Schnelle-Kreis, J. AU - Winterhalter, R.* AU - Müller, A.* AU - Nowak, D.* AU - Karrasch, S.* C1 - 74793 C2 - 57595 CY - Campus, 4 Crinan St, London N1 9xw, England TI - Acute health effects of ambient air pollution including ultrafine particles in a semi-experimental setting in young, healthy individuals. JO - Part. Fibre Toxicol. VL - 22 IS - 1 PB - Bmc PY - 2025 SN - 1743-8977 ER - TY - JOUR AB - BACKGROUND: Ambient air pollution is a major risk factor for CVDs, and a plausible mechanism is speculated to be alteration of autonomic nervous system (ANS) function. Yet, the short-term effects of air pollution on heart rate variability (HRV), a measure of ANS balance are inconsistent. OBJECTIVE: This study aimed to evaluate the short-term effects of ambient PM2.5 and NO2 on cardiovascular autonomic function, and to determine vulnerable subgroups and temporal trends from repeated HRV and HR measurements over 14 years in the KORA cohort. METHODS: We analyzed data from 4,032 participants in KORA S4 (1999-2001) and 1,912 in KORA FF4 (2013-2014). Air pollution data were from fixed monitoring stations, and HRV indices were derived from 5-minute ECG recordings. Generalized additive models (GAMs) and generalized additive mixed models (GAMMs) were used to assess associations. RESULTS: In S4, each IQR increase in PM2.5 at the 14-day moving average was associated with a 2.32% (95% CI: - 4.41, - 0.19) decrease in SDNN and a 1.20% (95% CI: 0.16, 2.26) increase in HR. By contrast, KORA FF4 showed opposite associations, with a 0.86% (95% CI: 0.02, 1.70) increase in SDNN at lag 4 for PM2.5. Effect modifications by age and smoking status were observed in S4. No statistically significant associations were found in the longitudinal analysis, however, the observed trends were consistent with the effects identified in S4. CONCLUSION: Short-term exposure to PM2.5 and NO2 impacts cardiac autonomic function, with varying effects across study waves due to aging, smoking, medication, and lower pollution levels. Even at low ambient concentrations, these exposures impaired autonomic function via inflammation and oxidative stress, underscoring the importance of stringent air quality standards and lifestyle interventions in reducing cardiovascular risk. AU - Li, Y. AU - Breitner-Busch, S. AU - Cascio, W.E.* AU - Zhang, S.* AU - Wolf, K. AU - Rückert-Eheberg, I.-M. AU - Kääb, S.* AU - Schmidt, G.* AU - Strom, A.* AU - Peters, A. AU - Schneider, A.E. C1 - 75809 C2 - 58058 CY - Campus, 4 Crinan St, London N1 9xw, England TI - Short-term association between ambient air pollution and heart rate variability: Results from the population-based KORA S4 and FF4 studies. JO - Part. Fibre Toxicol. VL - 22 IS - 1 PB - Bmc PY - 2025 SN - 1743-8977 ER - TY - JOUR AB - BACKGROUND: The formation of secondary organic aerosols (SOA) by atmospheric oxidation reactions substantially contributes to the burden of fine particulate matter (PM2.5), which has been associated with adverse health effects (e.g., cardiovascular diseases). However, the molecular and cellular effects of atmospheric aging on aerosol toxicity have not been fully elucidated, especially in model systems that enable cell-to-cell signaling. METHODS: In this study, we aimed to elucidate the complexity of atmospheric aerosol toxicology by exposing a coculture model system consisting of an alveolar (A549) and an endothelial (EA.hy926) cell line seeded in a 3D orientation at the air‒liquid interface for 4 h to model aerosols. Simulation of atmospheric aging was performed on volatile biogenic (β-pinene) or anthropogenic (naphthalene) precursors of SOA condensing on soot particles. The similar physical properties for both SOA, but distinct differences in chemical composition (e.g., aromatic compounds, oxidation state, unsaturated carbonyls) enabled to determine specifically induced toxic effects of SOA. RESULTS: In A549 cells, exposure to naphthalene-derived SOA induced stress-related airway remodeling and an early type I immune response to a greater extent. Transcriptomic analysis of EA.hy926 cells not directly exposed to aerosol and integration with metabolome data indicated generalized systemic effects resulting from the activation of early response genes and the involvement of cardiovascular disease (CVD) -related pathways, such as the intracellular signal transduction pathway (PI3K/AKT) and pathways associated with endothelial dysfunction (iNOS; PDGF). Greater induction following anthropogenic SOA exposure might be causative for the observed secondary genotoxicity. CONCLUSION: Our findings revealed that the specific effects of SOA on directly exposed epithelial cells are highly dependent on the chemical identity, whereas non directly exposed endothelial cells exhibit more generalized systemic effects with the activation of early stress response genes and the involvement of CVD-related pathways. However, a greater correlation was made between the exposure to the anthropogenic SOA compared to the biogenic SOA. In summary, our study highlights the importance of chemical aerosol composition and the use of cell systems with cell-to-cell interplay on toxicological outcomes. AU - Offer, S. AU - Di Bucchianico, S. AU - Czech, H. AU - Pardo, M.* AU - Pantzke, J. AU - Bisig, B. AU - Schneider, E.* AU - Bauer, S. AU - Zimmermann, E. AU - Oeder, S. AU - Hartner, E. AU - Gröger, T.M. AU - Alsaleh, R.* AU - Kersch, C.* AU - Ziehm, T.* AU - Hohaus, T.* AU - Rüger, C.P.* AU - Schmitz-Spanke, S.* AU - Schnelle-Kreis, J. AU - Sklorz, M. AU - Kiendler-Scharr, A.* AU - Rudich, Y.* AU - Zimmermann, R. C1 - 71778 C2 - 56429 CY - Campus, 4 Crinan St, London N1 9xw, England TI - The chemical composition of secondary organic aerosols regulates transcriptomic and metabolomic signaling in an epithelial-endothelial in vitro coculture. JO - Part. Fibre Toxicol. VL - 21 IS - 1 PB - Bmc PY - 2024 SN - 1743-8977 ER - TY - JOUR AB - BACKGROUND: Exposure to air pollution is associated with elevated cardiovascular risk. Evidence shows that omega-3 polyunsaturated fatty acids (omega-3 PUFA) may attenuate the adverse cardiovascular effects of exposure to fine particulate matter (PM2.5). However, it is unclear whether habitual dietary intake of omega-3 PUFA protects against the cardiovascular effects of short-term exposure to low-level ambient air pollution in healthy participants. In the present study, sixty-two adults with low or high dietary omega-3 PUFA intake were enrolled. Blood lipids, markers of vascular inflammation, coagulation and fibrinolysis, and heart rate variability (HRV) and repolarization were repeatedly assessed in 5 sessions separated by at least 7 days. This study was carried out in the Research Triangle area of North Carolina, USA between October 2016 and September 2019. Daily PM2.5 and maximum 8-h ozone (O3) concentrations were obtained from nearby air quality monitoring stations. Linear mixed-effects models were used to assess the associations between air pollutant concentrations and cardiovascular responses stratified by the omega-3 intake levels. RESULTS: The average concentrations of ambient PM2.5 and O3 were well below the U.S. National Ambient Air Quality Standards during the study period. Significant associations between exposure to PM2.5 and changes in total cholesterol, von Willebrand factor (vWF), tissue plasminogen activator, D-dimer, and very-low frequency HRV were observed in the low omega-3 group, but not in the high group. Similarly, O3-associated adverse changes in cardiovascular biomarkers (total cholesterol, high-density lipoprotein, serum amyloid A, soluable intracellular adhesion molecule 1, and vWF) were mainly observed in the low omega-3 group. Lag-time-dependent biphasic changes were observed for some biomarkers. CONCLUSIONS: This study demonstrates associations between short-term exposure to PM2.5 and O3, at concentrations below regulatory standard, and subclinical cardiovascular responses, and that dietary omega-3 PUFA consumption may provide protection against such cardiovascular effects in healthy adults. AU - Chen, H.* AU - Zhang, S. AU - Shen, W.* AU - Salazar, C.* AU - Schneider, A.E. AU - Wyatt, L.H.* AU - Rappold, A.G.* AU - Diaz-Sanchez, D.* AU - Devlin, R.B.* AU - Samet, J.M.* AU - Tong, H.* C1 - 64319 C2 - 51964 CY - Campus, 4 Crinan St, London N1 9xw, England TI - Omega-3 fatty acids attenuate cardiovascular effects of short-term exposure to ambient air pollution. JO - Part. Fibre Toxicol. VL - 19 IS - 1 PB - Bmc PY - 2022 SN - 1743-8977 ER - TY - JOUR AB - BACKGROUND: Physiologically based pharmacokinetic (PBPK) modeling is an important tool in predicting target organ dosimetry and risk assessment of nanoparticles (NPs). The methodology of building a multi-route PBPK model for NPs has not been established, nor systematically evaluated. In this study, we hypothesized that the traditional route-to-route extrapolation approach of PBPK modeling that is typically used for small molecules may not be appropriate for NPs. To test this hypothesis, the objective of this study was to develop a multi-route PBPK model for different sizes (1.4-200 nm) of gold nanoparticles (AuNPs) in adult rats following different routes of administration (i.e., intravenous (IV), oral gavage, intratracheal instillation, and endotracheal inhalation) using two approaches: a traditional route-to-route extrapolation approach for small molecules and a new approach that is based on route-specific data that we propose to be applied generally to NPs. RESULTS: We found that the PBPK model using this new approach had superior performance than the traditional approach. The final PBPK model was optimized rigorously using a Bayesian hierarchical approach with Markov chain Monte Carlo simulations, and then converted to a web-based interface using R Shiny. In addition, quantitative structure-activity relationships (QSAR) based multivariate linear regressions were established to predict the route-specific key biodistribution parameters (e.g., maximum uptake rate) based on the physicochemical properties of AuNPs (e.g., size, surface area, dose, Zeta potential, and NP numbers). These results showed the size and surface area of AuNPs were the main determinants for endocytic/phagocytic uptake rates regardless of the route of administration, while Zeta potential was an important parameter for the estimation of the exocytic release rates following IV administration. CONCLUSIONS: This study suggests that traditional route-to-route extrapolation approaches for PBPK modeling of small molecules are not applicable to NPs. Therefore, multi-route PBPK models for NPs should be developed using route-specific data. This novel PBPK-based web interface serves as a foundation for extrapolating to other NPs and to humans to facilitate biodistribution estimation, safety, and risk assessment of NPs. AU - Chou, W.C.* AU - Cheng, Y.H.* AU - Riviere, J.E.* AU - Monteiro-Riviere, N.A.* AU - Kreyling, W.G. AU - Lin, Z.* C1 - 65649 C2 - 52444 TI - Development of a multi-route physiologically based pharmacokinetic (PBPK) model for nanomaterials: A comparison between a traditional versus a new route-specific approach using gold nanoparticles in rats. JO - Part. Fibre Toxicol. VL - 19 IS - 1 PY - 2022 SN - 1743-8977 ER - TY - JOUR AB - BACKGROUND: Exposure to air pollutants is one of the major environmental health risks faced by populations globally. Information about inhaled particle deposition dose is crucial in establishing the dose-response function for assessing health-related effects due to exposure to air pollution. OBJECTIVE: This study aims to quantify the respiratory tract deposition (RTD) of equivalent black carbon (BC) particles in healthy young adults during a real-world commuting scenario, analyze factors affecting RTD of BC, and provide key parameters for the assessment of RTD. METHODS: A novel in situ method was applied to experimentally determine the RTD of BC particles among subjects in the highly polluted megacity of Metro Manila, Philippines. Exposure measurements were made for 40 volunteers during public transport and walking. RESULTS: The observed BC exposure concentration was up to 17-times higher than in developed regions. The deposition dose rate (DDR) of BC was up to 3 times higher during commute inside a public transport compared to walking (11.6 versus 4.4 μg hr-1, respectively). This is twice higher than reported in similar studies. The average BC mass deposition fraction (DF) was found to be 43 ± 16%, which can in large be described by individual factors and does not depend on gender. CONCLUSIONS: Commuting by open-sided public transport, commonly used in developing regions, poses a significant health risk due to acquiring extremely high doses of carcinogenic traffic-related pollutants. There is an urgent need to drastically update air pollution mitigation strategies for reduction of dangerously high emissions of BC in urban setting in developing regions. The presented mobile measurement set-up to determine respiratory tract deposition dose is a practical and cost-effective tool that can be used to investigate respiratory deposition in challenging environments. AU - Madueno, L.* AU - Kecorius, S. AU - Loendahl, J.* AU - Schnelle-Kreis, J. AU - Wiedensohler, A.* AU - Poehlker, M.* C1 - 66218 C2 - 52864 TI - A novel in-situ method to determine the respiratory tract deposition of carbonaceous particles reveals dangers of public commuting in highly polluted megacity. JO - Part. Fibre Toxicol. VL - 19 IS - 1 PY - 2022 SN - 1743-8977 ER - TY - JOUR AB - BACKGROUND: An important aspect of nanomaterial (NM) risk assessment is establishing relationships between physicochemical properties and key events governing the toxicological pathway leading to adverse outcomes. The difficulty of NM grouping can be simplified if the most toxicologically relevant dose metric is used to assess the toxicological dose-response. Here, we thoroughly investigated the relationship between acute and chronic inflammation (based on polymorphonuclear neutrophil influx (% PMN) in lung bronchoalveolar lavage) and the retained surface area in the lung. Inhalation studies were performed in rats with three classes of NMs: titanium dioxides (TiO2) and carbon blacks (CB) as poorly soluble particles of low toxicity (PSLT), and multiwall carbon nanotubes (MWCNTs). We compared our results to published data from nearly 30 rigorously selected articles. RESULTS: This analysis combined data specially generated for this work on three benchmark materials - TiO2 P25, the CB Printex-90 and the MWCNT MWNT-7 - following subacute (4-week) inhalation with published data relating to acute (1-week) to subchronic (13-week) inhalation exposure to the classes of NMs considered. Short and long post-exposure recovery times (immediately after exposure up to more than 6 months) allowed us to examine both acute and chronic inflammation. A dose-response relationship across short-term and long-term studies was revealed linking pulmonary retained surface area dose (measured or estimated) and % PMN. This relationship takes the form of sigmoid curves, and is independent of the post-exposure time. Curve fitting equations depended on the class of NM considered, and sometimes on the duration of exposure. Based on retained surface area, long and thick MWCNTs (few hundred nm long with an aspect ratio greater than 25) had a higher inflammatory potency with 5 cm2/g lung sufficient to trigger an inflammatory response (at 6% PMN), whereas retained surfaces greater than 150 cm2/g lung were required for PSLT. CONCLUSIONS: Retained surface area is a useful metric for hazard grouping purposes. This metric would apply to both micrometric and nanometric materials, and could obviate the need for direct measurement in the lung. Indeed, it could alternatively be estimated from dosimetry models using the aerosol parameters (rigorously determined following a well-defined aerosol characterization strategy). AU - Cosnier, F.* AU - Seidel, C.* AU - Valentino, S.* AU - Schmid, O. AU - Bau, S.* AU - Vogel, U.* AU - Devoy, J.* AU - Gaté, L.* C1 - 62756 C2 - 51035 CY - Campus, 4 Crinan St, London N1 9xw, England TI - Retained particle surface area dose drives inflammation in rat lungs following acute, subacute, and subchronic inhalation of nanomaterials. JO - Part. Fibre Toxicol. VL - 18 IS - 1 PB - Bmc PY - 2021 SN - 1743-8977 ER - TY - JOUR AB - Background: Pulmonary exposure to high doses of engineered carbonaceous nanomaterials (NMs) is known to trigger inflammation in the lungs paralleled by an acute phase response. Toll-like receptors (TLRs), particularly TLR2 and TLR4, have recently been discussed as potential NM-sensors, initiating inflammation. Using Tlr2 and Tlr4 knock out (KO) mice, we addressed this hypothesis and compared the pattern of inflammation in lung and acute phase response in lung and liver 24 h after intratracheal instillation of three differently shaped carbonaceous NMs, spherical carbon black (CB), multi-walled carbon nanotubes (CNT), graphene oxide (GO) plates and bacterial lipopolysaccharide (LPS) as positive control. Results: The LPS control confirmed a distinct TLR4-dependency as well as a pronounced contribution of TLR2 by reducing the levels of pulmonary inflammation to 30 and 60% of levels in wild type (WT) mice. At the doses chosen, all NM caused comparable neutrophil influxes into the lungs of WT mice, and reduced levels were only detected for GO-exposed Tlr2 KO mice (35%) and for CNT-exposed Tlr4 KO mice (65%). LPS-induced gene expression was strongly TLR4-dependent. CB-induced gene expression was unaffected by TLR status. Both GO and MWCNT-induced Saa1 expression was TLR4-dependent. GO-induced expression of Cxcl2, Cxcl5, Saa1 and Saa3 were TLR2-dependent. NM-mediated hepatic acute phase response in terms of liver gene expression of Saa1 and Lcn2 was shown to depend on TLR2 for all three NMs. TLR4, in contrast, was only relevant for the acute phase response caused by CNTs, and as expected by LPS. Conclusion: TLR2 and TLR4 signaling was not involved in the acute inflammatory response caused by CB exposure, but contributed considerably to that of GO and CNTs, respectively. The strong involvement of TLR2 in the hepatic acute phase response caused by pulmonary exposure to all three NMs deserves further investigations. AU - Danielsen, P.H.* AU - Bendtsen, K.M.* AU - Knudsen, K.B.* AU - Poulsen, S.S.* AU - Stöger, T. AU - Vogel, U.* C1 - 63408 C2 - 51423 CY - Campus, 4 Crinan St, London N1 9xw, England TI - Nanomaterial- and shape-dependency of TLR2 and TLR4 mediated signaling following pulmonary exposure to carbonaceous nanomaterials in mice. JO - Part. Fibre Toxicol. VL - 18 IS - 1 PB - Bmc PY - 2021 SN - 1743-8977 ER - TY - JOUR AB - Background Accurate knowledge of cell-/tissue-delivered dose plays a pivotal role in inhalation toxicology studies, since it is the key parameter for hazard assessment and translation of in vitro to in vivo dose-response. Traditionally, (nano-)particle toxicological studies with in vivo and in vitro models of the lung rely onin siliocomputational or off-line analytical methods for dosimetry. In contrast to traditional in vitro testing under submerged cell culture conditions, the more physiologic air-liquid interface (ALI) conditions offer the possibility for real-time dosimetry using quartz crystal microbalances (QCMs). However, it is unclear, if QCMs are sensitive enough for nanotoxicological studies. We investigated this issue for two commercially available VITROCELL (R) Cloud ALI exposure systems. Results Quantitative fluorescence spectroscopy of fluorescein-spiked saline aerosol was used to determine detection limit, precision and accuracy of the QCMs implemented in a VITROCELL (R) Cloud 6 and Cloud 12 system for dose-controlled ALI aerosol-cell exposure experiments. Both QCMs performed linearly over the entire investigated dose range (200 to 12,000 ng/cm(2)) with an accuracy of 3.4% (Cloud 6) and 3.8% (Cloud 12). Their precision (repeatability) decreased from 2.5% for large doses (> 9500 ng/cm(2)) to values of 10% and even 25% for doses of 1000 ng/cm(2)and 200 ng/cm(2), respectively. Their lower detection limit was 170 ng/cm(2)and 169 ng/cm(2)for the Cloud 6 and Cloud 12, respectively. Dose-response measurements with (NM110) ZnO nanoparticles revealed an onset dose of 3.3 mu g/cm(2)(or 0.39 cm(2)/cm(2)) for both cell viability (WST-1) and cytotoxicity (LDH) of A549 lung epithelial cells. Conclusions The QCMs of the Cloud 6 and Cloud 12 systems show similar performance and are highly sensitive, accurate devices for (quasi-) real-time dosimetry of the cell-delivered particle dose in ALI cell exposure experiments, if operated according to manufacturer specifications. Comparison with in vitro onset doses from this and previously published ALI studies revealed that the detection limit of 170 ng/cm(2)is sufficient for determination of toxicological onset doses for all particle types with low (e.g. polystyrene) or high mass-specific toxicity (e.g. ZnO and Ag) investigated here. Hence, in principle QCMs are suitable for in vitro nanotoxciological studies, but this should be investigated for each QCM and ALI exposure system under the specific exposure conditions as described in the present study. AU - Ding, Y. AU - Weindl, P. AU - Lenz, A.-G. AU - Mayer, P. AU - Krebs, T.* AU - Schmid, O. C1 - 60093 C2 - 49238 CY - Campus, 4 Crinan St, London N1 9xw, England TI - Quartz crystal microbalances (QCM) are suitable for real-time dosimetry in nanotoxicological studies using VITROCELL®Cloud cell exposure systems. JO - Part. Fibre Toxicol. VL - 17 IS - 1 PB - Bmc PY - 2020 SN - 1743-8977 ER - TY - JOUR AB - Toxicity testing and regulation of advanced materials at the nanoscale, i.e. nanosafety, is challenged by the growing number of nanomaterials and their property variants requiring assessment for potential human health impacts. The existing animal-reliant toxicity testing tools are onerous in terms of time and resources and are less and less in line with the international effort to reduce animal experiments. Thus, there is a need for faster, cheaper, sensitive and effective animal alternatives that are supported by mechanistic evidence. More importantly, there is an urgency for developing alternative testing strategies that help justify the strategic prioritization of testing or targeting the most apparent adverse outcomes, selection of specific endpoints and assays and identifying nanomaterials of high concern. The Adverse Outcome Pathway (AOP) framework is a systematic process that uses the available mechanistic information concerning a toxicological response and describes causal or mechanistic linkages between a molecular initiating event, a series of intermediate key events and the adverse outcome. The AOP framework provides pragmatic insights to promote the development of alternative testing strategies. This review will detail a brief overview of the AOP framework and its application to nanotoxicology, tools for developing AOPs and the role of toxicogenomics, and summarize various AOPs of relevance to inhalation toxicity of nanomaterials that are currently under various stages of development. The review also presents a network of AOPs derived from connecting all AOPs, which shows that several adverse outcomes induced by nanomaterials originate from a molecular initiating event that describes the interaction of nanomaterials with lung cells and involve similar intermediate key events. Finally, using the example of an established AOP for lung fibrosis, the review will discuss various in vitro tests available for assessing lung fibrosis and how the information can be used to support a tiered testing strategy for lung fibrosis. The AOPs and AOP network enable deeper understanding of mechanisms involved in inhalation toxicity of nanomaterials and provide a strategy for the development of alternative test methods for hazard and risk assessment of nanomaterials. AU - Halappanavar, S.* AU - van den Brule, S.* AU - Nymark, P.* AU - Gaté, L.* AU - Seidel, C.* AU - Valentino, S.* AU - Zhernovkov, V.* AU - Høgh Danielsen, P.* AU - De Vizcaya, A.* AU - Wolff, H.* AU - Stöger, T. AU - Boyadziev, A.* AU - Poulsen, S.S.* AU - Sørli, J.B.* AU - Vogel, U.* C1 - 59208 C2 - 48671 CY - Campus, 4 Crinan St, London N1 9xw, England TI - Adverse outcome pathways as a tool for the design of testing strategies to support the safety assessment of emerging advanced materials at the nanoscale. JO - Part. Fibre Toxicol. VL - 17 IS - 1 PB - Bmc PY - 2020 SN - 1743-8977 ER - TY - JOUR AB - Background Wood combustion emissions have been studied previously either by in vitro or in vivo models using collected particles, yet most studies have neglected gaseous compounds. Furthermore, a more accurate and holistic view of the toxicity of aerosols can be gained with parallel in vitro and in vivo studies using direct exposure methods. Moreover, modern exposure techniques such as air-liquid interface (ALI) exposures enable better assessment of the toxicity of the applied aerosols than, for example, the previous state-of-the-art submerged cell exposure techniques. Methods We used three different ALI exposure systems in parallel to study the toxicological effects of spruce and pine combustion emissions in human alveolar epithelial (A549) and murine macrophage (RAW264.7) cell lines. A whole-body mouse inhalation system was also used to expose C57BL/6 J mice to aerosol emissions. Moreover, gaseous and particulate fractions were studied separately in one of the cell exposure systems. After exposure, the cells and animals were measured for various parameters of cytotoxicity, inflammation, genotoxicity, transcriptome and proteome. Results We found that diluted (1:15) exposure pine combustion emissions (PM(1)mass 7.7 +/- 6.5 mg m(- 3), 41 mg MJ(- 1)) contained, on average, more PM and polycyclic aromatic hydrocarbons (PAHs) than spruce (PM(1)mass 4.3 +/- 5.1 mg m(- 3), 26 mg MJ(- 1)) emissions, which instead showed a higher concentration of inorganic metals in the emission aerosol. Both A549 cells and mice exposed to these emissions showed low levels of inflammation but significantly increased genotoxicity. Gaseous emission compounds produced similar genotoxicity and a higher inflammatory response than the corresponding complete combustion emission in A549 cells. Systems biology approaches supported the findings, but we detected differing responses between in vivo and in vitro experiments. Conclusions Comprehensive in vitro and in vivo exposure studies with emission characterization and systems biology approaches revealed further information on the effects of combustion aerosol toxicity than could be achieved with either method alone. Interestingly, in vitro and in vivo exposures showed the opposite order of the highest DNA damage. In vitro measurements also indicated that the gaseous fraction of emission aerosols may be more important in causing adverse toxicological effects. Combustion aerosols of different wood species result in mild but aerosol specific in vitro and in vivo effects. AU - Ihantola, T.* AU - Di Bucchianico, S. AU - Happo, M.* AU - Uski, O.* AU - Bauer, S. AU - Kuuspalo, K.* AU - Sippula, O.* AU - Tissari, J.* AU - Oeder, S. AU - Hartikainen, A.* AU - Rönkkö, T.J.* AU - Martikainen, M.-V.* AU - Huttunen, K.* AU - Vertiainen, P.* AU - Suhonen, H.* AU - Kortelainen, M.* AU - Lamberg, H.* AU - Leskinen, A.* AU - Sklorz, M. AU - Michalke, B. AU - Dilger, M.* AU - Weiss, C.* AU - Dittmar, G.* AU - Beckers, J. AU - Irmler, M. AU - Buters, J.T.M. AU - Cadeias, J. AU - Czech, H. AU - Yli-Pirilä, P.* AU - Abbaszade, G. AU - Jakobi, G. AU - Orasche, J. AU - Schnelle-Kreis, J. AU - Kanashova, T.* AU - Karg, E.W. AU - Streibel, T. AU - Passig, G.* AU - Hakkarainen, H.* AU - Jokiniemi, J.* AU - Zimmermann, R. AU - Hirvonen, M.-R.* AU - Jalava, P.I.* C1 - 59373 C2 - 48768 CY - Campus, 4 Crinan St, London N1 9xw, England TI - Influence of wood species on toxicity of log-wood stove combustion aerosols: A parallel animal and air-liquid interface cell exposure study on spruce and pine smoke. JO - Part. Fibre Toxicol. VL - 17 IS - 1 PB - Bmc PY - 2020 SN - 1743-8977 ER - TY - JOUR AB - Background There is a steadily increasing quantity of silver nanoparticles (AgNP) produced for numerous industrial, medicinal and private purposes, leading to an increased risk of inhalation exposure for both professionals and consumers. Particle inhalation can result in inflammatory and allergic responses, and there are concerns about other negative health effects from either acute or chronic low-dose exposure. Results To study the fate of inhaled AgNP, healthy adult rats were exposed to 11/2-hour intra-tracheal inhalations of pristine Ag-105-radiolabeled, 20 nm AgNP aerosols (with mean doses across all rats of each exposure group of deposited NP-mass and NP-number being 13.5 +/- 3.6 mu g, 7.9 +/- 3.2 center dot 10(11), respectively). At five time-points (0.75 h, 4 h, 24 h, 7d, 28d) post-exposure (p.e.), a complete balance of the [Ag-105]AgNP fate and its degradation products were quantified in organs, tissues, carcass, lavage and body fluids, including excretions. Rapid dissolution of [Ag-105]Ag-ions from the [Ag-105]AgNP surface was apparent together with both fast particulate airway clearance and long-term particulate clearance from the alveolar region to the larynx. The results are compatible with evidence from the literature that the released [Ag-105]Ag-ions precipitate rapidly to low-solubility [Ag-105]Ag-salts in the ion-rich epithelial lining lung fluid (ELF) and blood. Based on the existing literature, the degradation products rapidly translocate across the air-blood-barrier (ABB) into the blood and are eliminated via the liver and gall-bladder into the small intestine for fecal excretion. The pathway of [Ag-105]Ag-salt precipitates was compatible with auxiliary biokinetics studies at 24 h and 7 days after either intravenous injection or intratracheal or oral instillation of [Ag-110m]AgNO3 solutions in sentinel groups of rats. However, dissolution of [Ag-105]Ag-ions appeared not to be complete after a few hours or days but continued over two weeks p.e. This was due to the additional formation of salt layers on the [Ag-105]AgNP surface that mediate and prolonge the dissolution process. The concurrent clearance of persistent cores of [Ag-105]AgNP and [Ag-105]Ag-salt precipitates results in the elimination of a fraction > 0.8 (per ILD) after one week, each particulate Ag-species accounting for about half of this. After 28 days p.e. the cleared fraction rises marginally to 0.94 while 2/3 of the remaining [Ag-105]AgNP are retained in the lungs and 1/3 in secondary organs and tissues with an unknown partition of the Ag species involved. However, making use of our previous biokinetics studies of poorly soluble [Au-195]AuNP of the same size and under identical experimental and exposure conditions (Kreyling et al., ACS Nano 2018), the kinetics of the ABB-translocation of [Ag-105]Ag-salt precipitates was estimated to reach a fractional maximum of 0.12 at day 3 p.e. and became undetectable 16 days p.e. Hence, persistent cores of [Ag-105]AgNP were cleared throughout the study period. Urinary [Ag-105]Ag excretion is minimal, finally accumulating to 0.016.Conclusion The biokinetics of inhaled [Ag-105]AgNP is relatively complex since the dissolving [Ag-105]Ag-ions (a) form salt layers on the [Ag-105]AgNP surface which retard dissolution and (b) the [Ag-105]Ag-ions released from the [Ag-105]AgNP surface form poorly-soluble precipitates of [Ag-105]Ag-salts in ELF. Therefore, hardly any [Ag-105]Ag-ion clearance occurs from the lungs but instead [Ag-105]AgNP and nano-sized precipitated [Ag-105]Ag-salt are cleared via the larynx into GIT and, in addition, via blood, liver, gall bladder into GIT with one common excretional pathway via feces out of the body. AU - Kreyling, W.G. AU - Holzwarth, U.* AU - Hirn, S. AU - Schleh, C. AU - Wenk, A. AU - Schäffler, M. AU - Haberl, N. AU - Gibson, N.* C1 - 59304 C2 - 48722 CY - Campus, 4 Crinan St, London N1 9xw, England TI - Quantitative biokinetics over a 28 day period of freshly generated, pristine, 20 nm silver nanoparticle aerosols in healthy adult rats after a single 11/2-hour inhalation exposure. JO - Part. Fibre Toxicol. VL - 17 IS - 1 PB - Bmc PY - 2020 SN - 1743-8977 ER - TY - JOUR AB - BackgroundIndustrially produced quantities of TiO2 nanoparticles are steadily rising, leading to an increasing risk of inhalation exposure for both professionals and consumers. Particle inhalation can result in inflammatory and allergic responses, and there are concerns about other negative health effects from either acute or chronic low-dose exposure.ResultsTo study the fate of inhaled TiO2-NP, adult rats were exposed to 2-h intra-tracheal inhalations of V-48-radiolabeled, 20nm TiO2-NP aerosols (deposited NP-mass 1.40.5 mu g). At five time points (1h, 4h, 24h, 7d, 28d) post-exposure, a complete balance of the [V-48]TiO2-NP fate was quantified in organs, tissues, carcass, lavage and body fluids, including excretions.After fast mucociliary airway clearance (fractional range 0.16-0.31), long-term macrophage-mediated clearance (LT-MC) from the alveolar region is 2.6-fold higher after 28d (integral fraction 0.40 +/- 0.04) than translocation across the air-blood-barrier (integral fraction 0.15 +/- 0.01). A high NP fraction remains in the alveoli (0.44 +/- 0.05 after 28d), half of these on the alveolar epithelium and half in interstitial spaces. There is clearance from both retention sites at fractional rates (0.02-0.03 d(-1)) by LT-MC. Prior to LT-MC, [V-48]TiO2-NP are re-entrained to the epithelium as reported earlier for 20nm inhaled gold-NP (AuNP) and iridium-NP (IrNP).Conclusion Comparing the 28-day biokinetics patterns of three different inhaled NP materials TiO2-NP, AuNP and IrNP, the long-term kinetics of interstitial relocation and subsequent re-entrainment onto the lung-epithelium is similar for AuNP and Ir-NP but slower than for TiO2-NP. We discuss mechanisms and pathways of NP relocation and re-entrainment versus translocation. Additionally, after 28days the integral translocated fractions of TiO2-NP and IrNP across the air-blood-barrier (ABB) are similar and become 0.15 while the translocated AuNP fraction is only 0.04. While NP dissolution proved negligible, translocated TiO2-NP and IrNP are predominantly excreted in urine (0.1) while the urinary AuNP excretion amounts to a fraction of only 0.01. Urinary AuNP excretion is below 0.0001 during the first week but rises tenfold thereafter suggesting delayed disagglomeration. Of note, all three NP dissolve minimally, since no ionic radio-label release was detectable. These biokinetics data of inhaled, same-sized NP suggest significant time-dependent differences of the ABB translocation and subsequent fate in the organism. AU - Kreyling, W.G. AU - Holzwarth, U.* AU - Schleh, C. AU - Hirn, S. AU - Wenk, A. AU - Schäffler, M. AU - Haberl, N. AU - Semmler-Behnke, M. AU - Gibson, N.* C1 - 56541 C2 - 47084 CY - Campus, 4 Crinan St, London N1 9xw, England TI - Quantitative biokinetics over a 28day period of freshly generated, pristine, 20 nm titanium dioxide nanoparticle aerosols in healthy adult rats after a single two-hour inhalation exposure. JO - Part. Fibre Toxicol. VL - 16 IS - 1 PB - Bmc PY - 2019 SN - 1743-8977 ER - TY - JOUR AB - BackgroundParticles and fibres affect human health as a function of their properties such as chemical composition, size and shape but also depending on complex interactions in an organism that occur at various levels between particle uptake and target organ responses.While particulate pollution is one of the leading contributors to the global burden of disease, particles are also increasingly used for medical purposes. Over the past decades we have gained considerable experience in how particle properties and particle-bio interactions are linked to human health. This insight is useful for improved risk management in the case of unwanted health effects but also for developing novel medical therapies. The concepts that help us better understand particles' and fibres' risks include the fate of particles in the body; exposure, dosimetry and dose-metrics and the 5 Bs: bioavailability, biopersistence, bioprocessing, biomodification and bioclearance of (nano)particles. This includes the role of the biomolecule corona, immunity and systemic responses, non-specific effects in the lungs and other body parts, particle effects and the developing body, and the link from the natural environment to human health. The importance of these different concepts for the human health risk depends not only on the properties of the particles and fibres, but is also strongly influenced by production, use and disposal scenarios.ConclusionsLessons learned from the past can prove helpful for the future of the field, notably for understanding novel particles and fibres and for defining appropriate risk management and governance approaches. AU - Riediker, M.* AU - Zink, D.* AU - Kreyling, W.G. AU - Oberdörster, G.* AU - Elder, A.* AU - Graham, U.* AU - Lynch, I.* AU - Duschl, A.* AU - Ichihara, G.* AU - Ichihara, S.* AU - Kobayashi, T.* AU - Hisanaga, N.* AU - Umezawa, M.* AU - Cheng, T.J.* AU - Handy, R.* AU - Gulumian, M.* AU - Tinkle, S.* AU - Cassee, F.* C1 - 55927 C2 - 46678 CY - Campus, 4 Crinan St, London N1 9xw, England TI - Particle toxicology and health - where are we? JO - Part. Fibre Toxicol. VL - 16 IS - 1 PB - Bmc PY - 2019 SN - 1743-8977 ER - TY - JOUR AB - After the publication of this article [1] it was hihglighted that the number of deaths related to natural disasters was incorrectly reported in the second paragraph of the Hazards from Natural particulates and the evolution of the biosphere section. This correction article shows the correct and incorrect statement. This correction does not change the idea presented in the article that from an evolutionary view point, natural disasters account only for a small fraction of the people on the planet. The original article has been updated. AU - Riediker, M.* AU - Zink, D.* AU - Kreyling, W.G. AU - Oberdörster, G.* AU - Elder, A.* AU - Graham, U.* AU - Lynch, I.* AU - Duschl, A.* AU - Ichihara, G.* AU - Ichihara, S.* AU - Kobayashi, T.* AU - Hisanaga, N.* AU - Umezawa, M.* AU - Cheng, T.J.* AU - Handy, R.* AU - Gulumian, M.* AU - Tinkle, S.* AU - Cassee, F.* C1 - 56419 C2 - 47068 CY - Campus, 4 Crinan St, London N1 9xw, England TI - Particle toxicology and health - where are we? (vol 16, 19, 2019). JO - Part. Fibre Toxicol. VL - 16 IS - 1 PB - Bmc PY - 2019 SN - 1743-8977 ER - TY - JOUR AB - Background: Air pollution-induced changes in cardiac electrophysiological properties could be a pathway linking air pollution and cardiovascular events. The evidence of air pollution effects on the cardiac conduction system is incomplete yet. We investigated short-term effects of particulate matter <= 2.5 mu m in aerodynamic diameter (PM2.5) and ozone (O-3) on cardiac electrical impulse propagation and repolarization as recorded in surface electrocardiograms (ECG).Methods: We analyzed repeated 12-lead ECG measurements performed on 5,332 patients between 2001 and 2012. The participants came from the Duke CATHGEN Study who underwent cardiac catheterization and resided in North Carolina, United States (NC, U.S.). Daily concentrations of PM2.5 and O-3 at each participant's home address were predicted with a hybrid air quality exposure model. We used generalized additive mixed models to investigate the associations of PM2.5 and O-3 with the PR interval, QRS interval, heart rate-corrected QT interval (QTc), and heart rate (HR). The temporal lag structures of the associations were examined using distributed-lag models.Results: Elevated PM2.5 and O-3 were associated with four-day lagged lengthening of the PR and QRS intervals, and with one-day lagged increases in HR. We observed immediate effects on the lengthening of the QTc interval for both PM2.5 and O-3, as well as delayed effects for PM2.5 (lagged by 3 - 4 days). The associations of PM2.5 and O-3 with the PR interval and the association of O-3 with the QRS interval persisted until up to seven days after exposure.Conclusions: In patients undergoing cardiac catheterization, short-term exposure to air pollution was associated with increased HR and delays in atrioventricular conduction, ventricular depolarization and repolarization. AU - Zhang, S. AU - Breitner-Busch, S. AU - Cascio, W.E.* AU - Devlin, R.B.* AU - Neas, L.M.* AU - Diaz-Sanchez, D.* AU - Kraus, W.E.* AU - Schwartz, J.* AU - Hauser, E.R.* AU - Peters, A. AU - Schneider, A.E. C1 - 54503 C2 - 45639 CY - Campus, 4 Crinan St, London N1 9xw, England TI - Short-term effects of fine particulate matter and ozone on the cardiac conduction system in patients undergoing cardiac catheterization. JO - Part. Fibre Toxicol. VL - 15 IS - 1 PB - Bmc PY - 2018 SN - 1743-8977 ER - TY - JOUR AB - BACKGROUND: The death toll associated with inhaled ambient particulate matter (PM) is attributed mainly to cardio-vascular rather than pulmonary effects. However, it is unclear whether the key event for cardiovascular impairment is particle translocation from lung to circulation (direct effect) or indirect effects due to pulmonary particle-cell interactions. In this work, we addressed this issue by exposing healthy mice via inhalation and intra-arterial infusion (IAI) to carbon nanoparticles (CNP) as surrogate for soot, a major constituent of (ultrafine) urban PM. METHODS: Equivalent surface area CNP doses in the blood (30mm(2) per animal) were applied by IAI or inhalation (lung-deposited dose 10,000mm(2); accounting for 0.3% of lung-to-blood CNP translocation). Mice were analyzed for changes in hematology and molecular markers of endothelial/epithelial dysfunction, pro-inflammatory reactions, oxidative stress, and coagulation in lungs and extra-pulmonary organs after CNP inhalation (4 h and 24 h) and CNP infusion (4 h). For methodological reasons, we used two different CNP types (spark-discharge and Printex90), with very similar physicochemical properties [≥98 and ≥95% elemental carbon; 10 and 14 nm primary particle diameter; and 800 and 300 m(2)/g specific surface area] for inhalation and IAI respectively. RESULTS: Mild pulmonary inflammatory responses and significant systemic effects were observed following 4 h and 24 h CNP inhalation. Increased retention of activated leukocytes, secondary thrombocytosis, and pro-inflammatory responses in secondary organs were detected following 4 h and 24 h of CNP inhalation only. Interestingly, among the investigated extra-pulmonary tissues (i.e. aorta, heart, and liver); aorta revealed as the most susceptible extra-pulmonary target following inhalation exposure. Bypassing the lungs by IAI however did not induce any extra-pulmonary effects at 4 h as compared to inhalation. CONCLUSIONS: Our findings indicate that extra-pulmonary effects due to CNP inhalation are dominated by indirect effects (particle-cell interactions in the lung) rather than direct effects (translocated CNPs) within the first hours after exposure. Hence, CNP translocation may not be the key event inducing early cardiovascular impairment following air pollution episodes. The considerable response detected in the aorta after CNP inhalation warrants more emphasis on this tissue in future studies. AU - Ganguly, K.* AU - Ettehadieh, D. AU - Upadhyay, S.* AU - Takenaka, S. AU - Adler, T. AU - Karg, E.W. AU - Krombach, F.* AU - Kreyling, W.G. AU - Schulz, H. AU - Schmid, O. AU - Stöger, T. C1 - 51387 C2 - 43174 CY - London TI - Early pulmonary response is critical for extra-pulmonary carbon nanoparticle mediated effects: Comparison of inhalation versus intra-arterial infusion exposures in mice.   JO - Part. Fibre Toxicol. VL - 14 IS - 1 PB - Biomed Central Ltd PY - 2017 SN - 1743-8977 ER - TY - JOUR AB - BACKGROUND: We previously showed that cerium oxide (CeO2), barium sulfate (BaSO4) and zinc oxide (ZnO) nanoparticles (NPs) exhibited different lung toxicity and pulmonary clearance in rats. We hypothesize that these NPs acquire coronas with different protein compositions that may influence their clearance from the lungs. METHODS: CeO2, silica-coated CeO2, BaSO4, and ZnO NPs were incubated in rat lung lining fluid in vitro. Then, gel electrophoresis followed by quantitative mass spectrometry was used to characterize the adsorbed proteins stripped from these NPs. We also measured uptake of instilled NPs by alveolar macrophages (AMs) in rat lungs using electron microscopy. Finally, we tested whether coating of gold NPs with albumin would alter their lung clearance in rats. RESULTS: We found that the amounts of nine proteins in the coronas formed on the four NPs varied significantly. The amounts of albumin, transferrin and α-1 antitrypsin were greater in the coronas of BaSO4 and ZnO than that of the two CeO2 NPs. The uptake of BaSO4 in AMs was less than CeO2 and silica-coated CeO2 NPs. No identifiable ZnO NPs were observed in AMs. Gold NPs coated with albumin or citrate instilled into the lungs of rats acquired the similar protein coronas and were cleared from the lungs to the same extent. CONCLUSIONS: We show that different NPs variably adsorb proteins from the lung lining fluid. The amount of albumin in the NP corona varies as does NP uptake by AMs. However, albumin coating does not affect the translocation of gold NPs across the air-blood barrier. A more extensive database of corona composition of a diverse NP library will develop a platform to help predict the effects and biokinetics of inhaled NPs. AU - Konduru, N.V.* AU - Molina, R.M.* AU - Swami, A.* AU - Damiani, F.* AU - Pyrgiotakis, G.* AU - Lin, P.* AU - Andreozzi, P.* AU - Donaghey, T.C.* AU - Demokritou, P.* AU - Krol, S.* AU - Kreyling, W.G. AU - Brain, J.D.* C1 - 52242 C2 - 43854 CY - London TI - Protein corona: Implications for nanoparticle interactions with pulmonary cells. JO - Part. Fibre Toxicol. VL - 14 IS - 1 PB - Biomed Central Ltd PY - 2017 SN - 1743-8977 ER - TY - JOUR AB - Background: Inhalation of environmental (nano) particles (NP) as well as persistent herpesvirus-infection are potentially associated with chronic lung disease and as both are omnipresent in human society a coincidence of these two factors is highly likely. We hypothesized that NP-exposure of persistently herpesvirus-infected cells as a second hit might disrupt immune control of viral latency, provoke reactivation of latent virus and eventually lead to an inflammatory response and tissue damage. Results: To test this hypothesis, we applied different NP to cells or mice latently infected with murine gammaherpesvirus 68 (MHV-68) which provides a small animal model for the study of gammaherpesvirus-pathogenesis in vitro and in vivo. In vitro, NP-exposure induced expression of the typically lytic viral gene ORF50 and production of lytic virus. In vivo, lytic viral proteins in the lung increased after intratracheal instillation with NP and elevated expression of the viral gene ORF50 could be detected in cells from bronchoalveolar lavage. Gene expression and metabolome analysis of whole lung tissue revealed patterns with striking similarities to acute infection. Likewise, NP-exposure of human cells latently infected with Epstein-Barr-Virus also induced virus production. Conclusions: Our results indicate that NP-exposure of persistently herpesvirus-infected cells - murine or human - restores molecular signatures found in acute virus infection, boosts production of lytic viral proteins, and induces an inflammatory response in the lung - a combination which might finally result in tissue damage and pathological alterations. AU - Sattler, C. AU - Moritz, F. AU - Chen, S. AU - Steer, B. AU - Kutschke, D. AU - Irmler, M. AU - Beckers, J. AU - Eickelberg, O. AU - Schmitt-Kopplin, P. AU - Adler, H. AU - Stöger, T. C1 - 50330 C2 - 42390 CY - London TI - Nanoparticle exposure reactivates latent herpesvirus and restores a signature of acute infection. JO - Part. Fibre Toxicol. VL - 14 IS - 1 PB - Biomed Central Ltd PY - 2017 SN - 1743-8977 ER - TY - JOUR AU - Schmid, O. AU - Cassee, F.R.* C1 - 52573 C2 - 44055 CY - London TI - On the pivotal role of dose for particle toxicology and risk assessment: exposure is a poor surrogate for delivered dose. JO - Part. Fibre Toxicol. VL - 14 IS - 1 PB - Biomed Central Ltd PY - 2017 SN - 1743-8977 ER - TY - JOUR AB - BACKGROUND: Carbonaceous nanoparticles (CNP) represent a major constituent of urban particulate air pollution, and inhalation of high CNP levels has been described to trigger a pro-inflammatory response of the lung. While several studies identified specific particle characteristics driving respiratory toxicity of low-solubility and low-toxicity particles such as CNP, the major lung cell type, which initiates and drives that response, remains still uncertain. Since alveolar macrophages (AM) are known to effectively phagocytose inhaled particles and play a crucial role for the initiation of pulmonary inflammation caused by invading microbes, we aimed to determine their role for sterile stimuli such as CNP by profiling the primary alveolar cell compartments of the lung. We exposed C57BL/6 mice to 20 μg CNP by intratracheal instillation and comprehensively investigated the expression of the underlying mediators during a time span of 3 to 72 h in three different lung cell populations: CD45- (negative) structural cells, CD45+ (positive) leukocytes, and by BAL recovered cells. RESULTS: Bronchoalveolar lavage (BAL) analysis revealed an acute inflammatory response characterized by the most prominent culmination of neutrophil granulocytes from 12 to 24 h after instillation, which declined to basal levels by day 7. As early as 3 h after CNP exposure 50 % of the AM revealed particle laden. BAL concentrations and lung gene expression profiles of TNFα, and the neutrophil chemoattractants CXCL1,-2 and-5 preceded the neutrophil recruitment and showed highest levels after 12 h of CNP exposure, pointing to a significant activation of the inflammation-evoking lung cells at this point of time. AM, isolated from lungs 3 to 12 h after CNP instillation, however, did not show a pro-inflammatory signature. On the contrary, gene expression analysis of different lung cell populations isolated 12 h after CNP instillation revealed CD45-, mainly representing alveolar epithelial type II (ATII) cells as major producer of inflammatory CXCL cytokines. Particularly by CD45- cells expressed Cxcl5 proved to be the most abundant chemokine, being 12 h after CNP exposure 24 (±11) fold induced. CONCLUSION: Our data suggests that AM are noninvolved in the initiation of the inflammatory response. ATII cells, which induced highest CXCL levels early on, might in contrast be the driver of acute neutrophilic inflammation upon pulmonary CNP exposure. AU - Chen, S. AU - Yin, R. AU - Mutze, K. AU - Yu, Y. AU - Takenaka, S. AU - Königshoff, M. AU - Stöger, T. C1 - 48869 C2 - 41445 CY - London TI - No involvement of alveolar macrophages in the initiation of carbon nanoparticle induced acute lung inflammation in mice. JO - Part. Fibre Toxicol. VL - 13 IS - 1 PB - Biomed Central Ltd PY - 2016 SN - 1743-8977 ER - TY - JOUR AB - Although mass emissions of combustion-generated particulate matter have been substantially reduced by new combustion technology, there is still a great concern about the emissions of huge numbers of sub-10 nm particles with insignificant mass. These particles have up to orders of magnitude higher surface area to mass ratios compared to larger particles, have surfaces covered with adsorbed volatile and semi-volatile organic species or even are constituted by such species. Currently there is only very little information available on exposure and related health effects specific for smaller particles and first evidences for long-term health effects has only been recently published. However, the fact that these nanoparticles are not easily measured at the exhausts and in the atmosphere and that their biological activity is obscure does not mean that we can overlook them. There is an urgent need to develop i) reliable methods to measure sub-10 nm particles at the exhaust and in the atmosphere and ii) a robust correlation between the chemical structure of the molecules making up combustion-generated nanoparticles and health burden of new combustion technologies. Our attention has to turn to this new class of combustion-generated nanoparticles, which might be the future major constituents of air pollution. AU - Pedata, P.* AU - Stöger, T. AU - Zimmermann, R. AU - Peters, A. AU - Oberdörster, G.* AU - D'Anna, A.* C1 - 47159 C2 - 39164 TI - "Are we forgetting the smallest, sub 10 nm combustion generated particles?" JO - Part. Fibre Toxicol. VL - 12 IS - 1 PY - 2015 SN - 1743-8977 ER - TY - JOUR AB - Background The health effects of short-term exposure to ambient ultrafine particles in micro-environments are still under investigation. Methods Sixty-four individuals with type 2 diabetes and impaired glucose tolerance recorded ambulatory electrocardiograms over five to six hours on 191 occasions in a panel study in Augsburg, Germany. Personal exposure to particle number concentrations (PNC) was monitored for each individual on 5-minute basis concurrently and particulate matter with an aerodynamic diameter < 2.5 μm (PM2.5) was acquired from a central monitoring site on an hourly basis. Results More than 11,000 5-minute intervals were available for heart rate and measures of heart rate variability including SDNN (standard deviation of NN intervals). A concurrent decrease in 5-minute SDNN of −0.56% (95% confidence limits (CI): −1.02%; −0.09%) and a 5-minute delayed increase in heart rate of 0.23 % (95% CI: 0.11%; 0.36%) was observed with an increase in personal PNC of 16,000 per cm3 in additive mixed models. Models evaluating the association of concurrent 5-minute personal PNC and of 1-hour PM2.5 showed independent effects on SDNN. Conclusion The data suggest that freshly emitted ultrafine particles and aged fine particulate matter are both associated with changes in cardiac function in individuals with type 2 diabetes and impaired glucose tolerance in urban areas.   AU - Peters, A. AU - Hampel, R. AU - Cyrys, J. AU - Breitner-Busch, S. AU - Geruschkat, U. AU - Kraus, U. AU - Zareba, W.* AU - Schneider, A.E. C1 - 44375 C2 - 36804 CY - London TI - Elevated particle number concentrations induce immediate changes in heart rate variability: A panel study in individuals with impaired glucose metabolism or diabetes. JO - Part. Fibre Toxicol. VL - 12 IS - 1 PB - Biomed Central Ltd PY - 2015 SN - 1743-8977 ER - TY - JOUR AB - Background: The challenge remains to reliably mimic human exposure to high aspect ratio nanoparticles (HARN) via inhalation. Sophisticated, multi-cellular in vitro models are a particular advantageous solution to this issue, especially when considering the need to provide realistic and efficient alternatives to invasive animal experimentation for HARN hazard assessment. By incorporating a systematic test-bed of material characterisation techniques, a specific air-liquid cell exposure system with real-time monitoring of the cell-delivered HARN dose in addition to key biochemical endpoints, here we demonstrate a successful approach towards investigation of the hazard of HARN aerosols in vitro. Methods: Cellulose nanocrystals (CNCs) derived from cotton and tunicates, with differing aspect ratios (~9 and ~80), were employed as model HARN samples. Specifically, well-dispersed and characterised CNC suspensions were aerosolised using an " Air Liquid Interface Cell Exposure System" (ALICE) at realistic, cell-delivered concentrations ranging from 0.14 to 1.57 μg/cm2. The biological impact (cytotoxicity, oxidative stress levels and pro-inflammatory effects) of each HARN sample was then assessed using a 3D multi-cellular in vitro model of the human epithelial airway barrier at the air liquid interface (ALI) 24 hours post-exposure. Additionally, the testing strategy was validated using both crystalline quartz (DQ12) as a positive particulate control in the ALICE system and long fibre amosite asbestos (LFA) to confirm the susceptibility of the in vitro model to a fibrous insult. Results: A rapid (≤4 min), controlled nebulisation of CNC suspensions enabled a dose-controlled and spatially homogeneous CNC deposition onto cells cultured under ALI conditions. Real-time monitoring of the cell-delivered CNC dose with a quartz crystal microbalance was accomplished. Independent of CNC aspect ratio, no significant cytotoxicity (p > 0.05), induction of oxidative stress, or (pro)-inflammatory responses were observed up to the highest concentration of 1.57 μg/cm2. Both DQ12 and LFA elicited a significant (p < 0.05) pro-inflammatory response at sub-lethal concentrations in vitro.Conclusion: In summary, whilst the present study highlights the benign nature of CNCs, it is the advanced technological and mechanistic approach presented that allows for a state of the art testing strategy to realistically and efficiently determine the in vitro hazard concerning inhalation exposure of HARN. AU - Endes, C.* AU - Schmid, O. AU - Kinnear, C.* AU - Mueller, S.* AU - Camarero-Espinosa, S.* AU - Vanhecke, D.* AU - Foster, E.J.* AU - Petri-Fink, A.* AU - Rothen-Rutishauser, B.M.* AU - Weder, C.* AU - Clift, M.J.D.* C1 - 34381 C2 - 35244 CY - London TI - An in vitro testing strategy towards mimicking the inhalation of high aspect ratio nanoparticles. JO - Part. Fibre Toxicol. VL - 11 IS - 1 PB - Biomed Central Ltd PY - 2014 SN - 1743-8977 ER - TY - JOUR AB - BACKGROUND: Persons with cystic fibrosis (CF) are at-risk for health effects from ambient air pollution but little is known about the interaction of nanoparticles (NP) with CF lungs. Here we study the distribution of inhaled NP in a murine CF model and aim to reveal mechanisms contributing to adverse effects of inhaled particles in susceptible populations. METHODS: Chloride channel defective CftrTgH (neoim) Hgu mice were used to analyze lung function, lung distribution and whole body biokinetics of inhaled NP, and inflammatory responses after intratracheal administration of NP. Distribution of 20-nm titanium dioxide NP in lungs was assessed on ultrathin sections immediately and 24 h after a one-hour NP inhalation. NP biokinetics was deduced from total and regional lung deposition and from whole body translocation of inhaled 30-nm iridium NP within 24 h after aerosol inhalation. Inflammatory responses were assessed within 7 days after carbon NP instillation. RESULTS: Cftr mutant females had moderately reduced lung compliance and slightly increased airway resistance compared to wild type mice. We found no genotype dependent differences in total, regional and head deposition or in secondary-organ translocation of inhaled iridium NP. Titanium dioxide inhalation resulted in higher NP uptake by alveolar epithelial cells in Cftr mutants. Instillation of carbon NP induced a comparable acute and transient inflammatory response in both genotypes. The twofold increase of bronchoalveolar lavage (BAL) neutrophils in Cftr mutant compared to wild type mice at day 3 but not at days 1 and 7, indicated an impaired capacity in inflammation resolution in Cftr mutants. Concomitant to the delayed decline of neutrophils, BAL granulocyte-colony stimulating factor was augmented in Cftr mutant mice. Anti-inflammatory 15-hydroxyeicosatetraenoic acid was generally significantly lower in BAL of Cftr mutant than in wild type mice. CONCLUSIONS: Despite lacking alterations in lung deposition and biokinetics of inhaled NP, and absence of significant differences in lung function, higher uptake of NP by alveolar epithelial cells and prolonged, acute inflammatory responses to NP exposure indicate a moderately increased susceptibility of lungs to adverse effects of inhaled NP in Cftr mutant mice and provides potential mechanisms for the increased susceptibility of CF patients to air pollution. AU - Geiser, M.* AU - Stöger, T. AU - Casaulta, M.* AU - Chen, S. AU - Semmler-Behnke, M. AU - Bolle, I. AU - Takenaka, S. AU - Kreyling, W.G. AU - Schulz, H. C1 - 31231 C2 - 34225 CY - London TI - Biokinetics of nanoparticles and susceptibility to particulate exposure in a murine model of cystic fibrosis. JO - Part. Fibre Toxicol. VL - 11 IS - 1 PB - Biomed Central Ltd PY - 2014 SN - 1743-8977 ER - TY - JOUR AB - BackgroundEpidemiological and experimental studies suggest that exposure to ultrafine particles (UFP) might aggravate the allergic inflammation of the lung in asthmatics.MethodsWe exposed 12 allergic asthmatics in two subgroups in a double-blinded randomized cross-over design, first to freshly generated ultrafine carbon particles (64 ¿g/m3; 6.1¿±¿0.4 × 105 particles/cm3 for 2 h) and then to filtered air or vice versa with a 28-day recovery period in-between. Eighteen hours after each exposure, grass pollen was instilled into a lung lobe via bronchoscopy. Another 24 hours later, inflammatory cells were collected by means of bronchoalveolar lavage (BAL). (Trial registration: NCT00527462)ResultsFor the entire study group, inhalation of UFP by itself had no significant effect on the allergen induced inflammatory response measured with total cell count as compared to exposure with filtered air (p¿=¿0.188). However, the subgroup of subjects, which inhaled UFP during the first exposure, exhibited a significant increase in total BAL cells (p¿=¿0.021), eosinophils (p¿=¿0.031) and monocytes (p¿=¿0.013) after filtered air exposure and subsequent allergen challenge 28 days later. Additionally, the potential of BAL cells to generate oxidant radicals was significantly elevated at that time point. The subgroup that was exposed first to filtered air and 28 days later to UFP did not reveal differences between sessions.ConclusionsOur data demonstrate that pre-allergen exposure to UFP had no acute effect on the allergic inflammation. However, the subgroup analysis lead to the speculation that inhaled UFP particles might have a long-term effect on the inflammatory course in asthmatic patients. This should be reconfirmed in further studies with an appropriate study design and sufficient number of subjects. AU - Schaumann, F.* AU - Frömke, C.* AU - Dijkstra, D.* AU - Alessandrini, F. AU - Windt, H.* AU - Karg, E.W. AU - Müller, M.* AU - Winkler, C.* AU - Braun, A.* AU - Koch, A.* AU - Hohlfeld, J.* AU - Behrendt, H. AU - Schmid, O. AU - Koch, W.* AU - Schulz, H. AU - Krug, N.* C1 - 32499 C2 - 35078 TI - Effects of ultrafine particles on the allergic inflammation in the lung of asthmatics: Results of a double-blinded randomized cross-over clinical pilot study. JO - Part. Fibre Toxicol. VL - 11 IS - 1 PY - 2014 SN - 1743-8977 ER - TY - JOUR AB - Background There is evidence that nanoparticles (NP) cross epithelial and endothelial body barriers. We hypothesized that gold (Au) NP, once in the blood circulation of pregnant rats, will cross the placental barrier during pregnancy size-dependently and accumulate in the fetal organism by 1. transcellular transport across the hemochorial placenta, 2. transcellular transport across amniotic membranes 3. transport through ~20 nm wide transtrophoblastic channels in a size dependent manner. The three AuNP sizes used to test this hypothesis are either well below, or of similar size or well above the diameters of the transtrophoblastic channels. Methods We intravenously injected monodisperse, negatively charged, radio-labelled 1.4 nm, 18 nm and 80 nm 198AuNP at a mass dose of 5, 3 and 27 μg/rat, respectively, into pregnant rats on day 18 of gestation and in non-pregnant control rats and studied the biodistribution in a quantitative manner based on the radio-analysis of the stably labelled 198AuNP after 24 hours. Results We observed significant biokinetic differences between pregnant and non-pregnant rats. AuNP fractions in the uterus of pregnant rats were at least one order of magnitude higher for each particle size roughly proportional to the enlarged size and weight of the pregnant uterus. All three sizes of 198AuNP were found in the placentas and amniotic fluids with 1.4 nm AuNP fractions being two orders of magnitude higher than those of the larger AuNP on a mass base. In the fetuses, only fractions of 0.0006 (30 ng) and 0.00004 (0.1 ng) of 1.4 nm and 18 nm AuNP, respectively, were detected, but no 80 nm AuNP (<0.000004 (<0.1 ng)). These data show that no AuNP entered the fetuses from amniotic fluids within 24 hours but indicate that AuNP translocation occurs across the placental tissues either through transtrophoblastic channels and/or via transcellular processes. Conclusion Our data suggest that the translocation of AuNP from maternal blood into the fetus is NP-size dependent which is due to mechanisms involving (1) transport through transtrophoblastic channels – also present in the human placenta – and/or (2) endocytotic and diffusive processes across the placental barrier.   AU - Semmler-Behnke, M. AU - Lipka, J. AU - Wenk, A. AU - Hirn, S. AU - Schäffler, M. AU - Tian, F. AU - Schmid, G.* AU - Oberdörster, G.* AU - Kreyling, W.G. C1 - 32564 C2 - 35177 TI - Size dependent translocation and fetal accumulation of gold nanoparticles from maternal blood in the rat. JO - Part. Fibre Toxicol. VL - 11 IS - 1 PY - 2014 SN - 1743-8977 ER - TY - JOUR AB - Background: Studies provide compelling evidences for particulate matter (PM) associated cardiovascular health effects. Elderly individuals, particularly those with preexisting conditions like hypertension are regarded to be vulnerable. Experimental data are warranted to reveal the molecular pathomechanism of PM related cardiovascular impairments among aged/predisposed individuals. Thus we investigated the cardiovascular effects of ultrafine carbon particles (UfCP) on aged (12-13 months) spontaneously hypertensive rats (SHRs) and compared the findings with our pervious study on adult SHRs (6-7 months) to identify age related predisposition events in cardiovascular compromised elderly individuals. Methods: Aged SHRs were inhalation exposed to UfCP for 24 h (~180 μg/m3) followed by radio-telemetric assessment for blood pressure (BP) and heart rate (HR). Bronchoalveolar lavage (BAL) fluid cell differentials, interleukin 6 (IL-6) and other proinflammatory cytokines; serum C-reactive protein (CRP) and haptoglobin (HPT); and plasma fibrinogen were measured. Transcript levels of hemeoxygenase 1 (HO-1), endothelin 1 (ET1), endothelin receptors A, B (ETA, ETB), tissue factor (TF), and plasminogen activator inhibitor-1 (PAI-1) were measured in the lung and heart to assess oxidative stress, endothelial dysfunction and coagulation cascade. Result: UfCP exposed aged SHRs exhibited increased BP (4.4%) and HR (6.3%) on 1st recovery day paralleled by a 58% increase of neutrophils and 25% increase of IL-6 in the BAL fluid. Simultaneously higher CRP, HPT and fibrinogen levels in exposed SHRs indicate systemic inflammation. HO-1, ET1, ET-A, ET-B, TF and PAI-1 were induced by 1.5-2.0 folds in lungs of aged SHRs on 1st recovery day. However, in UfCP exposed adult SHRs these markers were up-regulated (2.5-6 fold) on 3rd recovery day in lung without detectable pulmonary/systemic inflammation. Conclusions: The UfCP induced pulmonary and systemic inflammation in aged SHRs is associated with oxidative stress, endothelial dysfunction and disturbed coagulatory hemostasis. UfCP exposure increased BP and HR in aged SHRs rats which was associated with lung inflammation, and increased expression of inflammatory, vasoconstriction and coagulation markers as well as systemic changes in biomarkers of thrombosis in aged SHRs. Our study provides further evidence for potential molecular mechanisms explaining the increased risk of particle mediated cardiac health effects in cardiovascular compromised elderly individuals. AU - Upadhyay, S. AU - Stöger, T. AU - George, L.* AU - Schladweiler, M.C.* AU - Kodavanti, U.P.* AU - Ganguly, K. AU - Schulz, H. C1 - 32664 C2 - 35216 TI - Ultrafine carbon particle mediated cardiovascular impairment of aged spontaneously hypertensive rats. JO - Part. Fibre Toxicol. VL - 11 IS - 1 PY - 2014 SN - 1743-8977 ER - TY - JOUR AB - BACKGROUND: Inhalative nanocarriers for local or systemic therapy are promising. Gold nanoparticles (AuNP) have been widely considered as candidate material. Knowledge about their interaction with the lungs is required, foremost their uptake by surface macrophages and epithelial cells.Diseased lungs are of specific interest, since these are the main recipients of inhalation therapy. We, therefore, used Scnn1b-transgenic (Tg) mice as a model of chronic obstructive pulmonary disease (COPD) and compared uptake and localization of inhaled AuNP in surface macrophages and lung tissue to wild-type (Wt) mice. METHODS: Scnn1b-Tg and Wt mice inhaled a 21-nm AuNP aerosol for 2 h. Immediately (0 h) or 24 h thereafter, bronchoalveolar lavage (BAL) macrophages and whole lungs were prepared for stereological analysis of AuNP by electron microscopy. RESULTS: AuNP were mainly found as singlets or small agglomerates of <= 100 nm diameter, at the epithelial surface and within lung-surface structures. Macrophages contained also large AuNP agglomerates (> 100 nm). At 0 h after aerosol inhalation, 69.2+/-4.9% AuNP were luminal, i.e. attached to the epithelial surface and 24.0+/-5.9% in macrophages in Scnn1b-Tg mice. In Wt mice, 35.3+/-32.2% AuNP were on the epithelium and 58.3+/-41.4% in macrophages. The percentage of luminal AuNP decreased from 0 h to 24 h in both groups. At 24 h, 15.5+/-4.8% AuNP were luminal, 21.4+/-14.2% within epithelial cells and 63.0+/-18.9% in macrophages in Scnn1b-Tg mice. In Wt mice, 9.5+/-5.0% AuNP were luminal, 2.2+/-1.6% within epithelial cells and 82.8+/-0.2% in macrophages. BAL-macrophage analysis revealed enhanced AuNP uptake in Wt animals at 0 h and in Scnn1b-Tg mice at 24 h, confirming less efficient macrophage uptake and delayed clearance of AuNP in Scnn1b-Tg mice. CONCLUSIONS: Inhaled AuNP rapidly bound to the alveolar epithelium in both Wt and Scnn1b-Tg mice. Scnn1b-Tg mice showed less efficient AuNP uptake by surface macrophages and concomitant higher particle internalization by alveolar type I epithelial cells compared to Wt mice. This likely promotes AuNP depth translocation in Scnn1b-Tg mice, including enhanced epithelial targeting. These results suggest AuNP nanocarrier delivery as successful strategy for therapeutic targeting of alveolar epithelial cells and macrophages in COPD. AU - Geiser, M.* AU - Quaile, O.* AU - Wenk, A. AU - Wigge, C.* AU - Eigeldinger-Berthou, S.* AU - Hirn, S. AU - Schäffler, M. AU - Schleh, C. AU - Möller, W. AU - Mall, M.A.* AU - Kreyling, W.G. C1 - 25723 C2 - 31903 TI - Cellular uptake and localization of inhaled gold nanoparticles in lungs of mice with chronic obstructive pulmonary disease. JO - Part. Fibre Toxicol. VL - 10 IS - 1 PB - BioMed Central PY - 2013 SN - 1743-8977 ER - TY - JOUR AB - BACKGROUND: Due to its antibacterial properties, silver (Ag) has been used in more consumer products than any other nanomaterial so far. Despite the promising advantages posed by using Ag-nanoparticles (NPs), their interaction with mammalian systems is currently not fully understood. An exposure route via inhalation is of primary concern for humans in an occupational setting. Aim of this study was therefore to investigate the potential adverse effects of aerosolised Ag-NPs using a human epithelial airway barrier model composed of A549, monocyte derived macrophage and dendritic cells cultured in vitro at the air-liquid interface. Cell cultures were exposed to 20 nm citrate-coated Ag-NPs with a deposition of 30 and 278 ng/cm2 respectively and incubated for 4 h and 24 h. To elucidate whether any effects of Ag-NPs are due to ionic effects, Ag-Nitrate (AgNO3) solutions were aerosolised at the same molecular mass concentrations. RESULTS: Agglomerates of Ag-NPs were detected at 24 h post exposure in vesicular structures inside cells but the cellular integrity was not impaired upon Ag-NP exposures. Minimal cytotoxicity, by measuring the release of lactate dehydrogenase, could only be detected following a higher concentrated AgNO3-solution. A release of pro-inflammatory markers TNF-alpha and IL-8 was neither observed upon Ag-NP and AgNO3 exposures as well as was not affected when cells were pre-stimulated with lipopolysaccharide (LPS). Also, an induction of mRNA expression of TNF-alpha and IL-8, could only be observed for the highest AgNO3 concentration alone or even significantly increased when pre-stimulated with LPS after 4 h. However, this effect disappeared after 24 h. Furthermore, oxidative stress markers (HMOX-1, SOD-1) were expressed after 4 h in a concentration dependent manner following AgNO3 exposures only. CONCLUSIONS: With an experimental setup reflecting physiological exposure conditions in the human lung more realistic, the present study indicates that Ag-NPs do not cause adverse effects and cells were only sensitive to high Ag-ion concentrations. Chronic exposure scenarios however, are needed to reveal further insight into the fate of Ag-NPs after deposition and cell interactions. AU - Herzog, F.* AU - Clift, M.J.* AU - Piccapietra, F.* AU - Behra, R.* AU - Schmid, O. AU - Petri-Fink, A.* AU - Rothen-Rutishauser, B.* C1 - 26158 C2 - 32098 TI - Exposure of silver-nanoparticles and silver-ions to lung cells in vitro at the air-liquid interface. JO - Part. Fibre Toxicol. VL - 10 IS - 1 PB - Biomed Central PY - 2013 SN - 1743-8977 ER - TY - JOUR AB - The article of Gasser et al. [Part Fibre Toxicol. 24; 9:17, 2012] describes the interaction of carbon nanotubes with cells within a complex cell culture model. Besides various toxicity parameters, the influence of coating with pulmonary surfactant was investigated. Pulmonary surfactant covers the entire alveolar region with the main function of decreasing the surface tension in the alveoli to prevent alveolar collapse. Although each inhaled nanoparticle, reaching the alveoli, will come into contact with pulmonary surfactant which will probably lead to a surfactant coating, pulmonary surfactant components are not commonly integrated in in vitro systems. Gasser and co-workers have shown that this surfactant coating is able to influence the further interaction with cellular systems. Hence, each scientist, working with in vitro systems and nanoparticles, should think of integrating pulmonary surfactant structures in order to harmonize the in vitro systems with the in vivo situation. In the present commentary we discuss the most important points of the manuscript of Gasser et al. and discuss where the usage of pulmonary surfactant can be further optimized. AU - Schleh, C.* AU - Kreyling, W.G. AU - Lehr, C.M.* C1 - 26222 C2 - 32130 TI - Pulmonary surfactant is indispensable in order to simulate the in vivo situation. JO - Part. Fibre Toxicol. VL - 10 IS - 1 PB - Biomed Central PY - 2013 SN - 1743-8977 ER - TY - JOUR AB - BACKGROUND: Exposure to ultrafine particles exerts diverse harmful effects including aggravation ofpulmonary diseases like asthma. Recently we demonstrated in a mouse model for allergicairway inflammation that particle-derived oxidative stress plays a crucial role duringaugmentation of allergen-induced lung inflammation by ultrafine carbon particle (UfCP)inhalation. The mechanisms how particle inhalation might change the inflammatory balancein the lungs, leading to accelerated inflammatory reactions, remain unclear. Lipid mediators,known to be immediately generated in response to tissue injury, might be strong candidatesfor priming this particle-triggered change of the inflammatory balance. METHODS: We hypothesize that inhalation of UfCP may disturb the balance of pro- and antiinflammatorylipid mediators in: i) a model for acute allergic pulmonary inflammation,exposing mice for 24 h before allergen challenge to UfCP inhalation (51.7 nm, 507 ìg/m3),and ii) an in-vitro model with primary rat alveolar macrophages (AM) incubated with UfCP(10 ìg/1 x 106 cells/ml) for 1 h. Lungs and AM were analysed for pro- and anti-inflammatorylipid mediators, namely leukotriene B4 (LTB4), prostaglandin E2 (PGE2), 15(S)-hydroxyeicosatetraenoicacid (15(S)-HETE), lipoxin A4 (LXA4) and oxidative stress marker 8-isoprostane by enzyme immunoassays and immunohistochemistry. RESULTS: In non-sensitized mice UfCP exposure induced a light non-significant increase of all lipidmediators. Similarly but significantly in rat AM all lipid mediators were induced alreadywithin 1 h of UfCP stimulation. Also sensitized and challenge mice exposed to filtered airshowed a partially significant increase in all lipid mediators. In sensitized and challengedmice UfCP exposure induced highest significant levels of all lipid mediators in the lungstogether with the peak of allergic airway inflammation on day 7 after UfCP inhalation. Thelevels of LTB4, 8-isoprostane and PGE2 were significantly increased also one day after UfCPexposure. Immunohistochemistry localized highest concentrations of PGE2 especially in AMone day after UfCP exposure. CONCLUSION: Our results suggest that UfCP exposure affects the balance between pro- and antiinflammatorylipid mediators. In allergic mice, where the endogenous balance of pro- andanti-inflammatory mediators is already altered, UfCP exposure aggravates the inflammationand the increase in anti-inflammatory, pro-resolving lipid mediators is insufficient tocounterbalance the extensive inflammatory response. This may be a contributing mechanismthat explains the increased susceptibility of asthmatic patients towards particle exposure. AU - Beck-Speier, I. AU - Karg, E.W. AU - Behrendt, H. AU - Stöger, T. AU - Alessandrini, F. C1 - 8341 C2 - 30064 CY - London TI - Ultrafine particles affect the balance of endogenous pro- and anti-inflammatory lipid mediators in the lung: In-vitro and in-vivo studies. JO - Part. Fibre Toxicol. VL - 9 IS - 1 PB - BioMed Central PY - 2012 SN - 1743-8977 ER - TY - JOUR AB - Concerns over the health effects of nanomaterials in the environment have created a need for microscopy methods capable of examining the biological interactions of nanoparticles (NP). Unfortunately, NP are beyond the diffraction limit of resolution for conventional light microscopy (~200 nm). Fluorescence and electron microscopy techniques commonly used to examine NP interactions with biological substrates have drawbacks that limit their usefulness in toxicological investigation of NP. EM is labor intensive and slow, while fluorescence carries the risk of photobleaching the sample and has size resolution limits. In addition, many relevant particles lack intrinsic fluorescence and therefore can not be detected in this manner. To surmount these limitations, we evaluated the potential of a novel combination of darkfield and confocal laser scanning microscopy (DF-CLSM) for the efficient 3D detection of NP in human lung cells. The DF-CLSM approach utilizes the contrast enhancements of darkfield microscopy to detect objects below the diffraction limit of 200 nm based on their light scattering properties and interfaces it with the power of confocal microscopy to resolve objects in the z-plane. Validation of the DF-CLSM method using fluorescent polystyrene beads demonstrated spatial colocalization of particle fluorescence (Confocal) and scattered transmitted light (Darkfield) along the X, Y, and Z axes. DF-CLSM imaging was able to detect and provide reasonable spatial locations of 27 nm TiO2 particles in relation to the stained nuclei of exposed BEAS 2B cells. Statistical analysis of particle proximity to cellular nuclei determined a significant difference between 5 min and 2 hr particle exposures suggesting a time-dependent internalization process. DF-CLSM microscopy is an alternative to current conventional light and electron microscopy methods that does not rely on particle fluorescence or contrast in electron density. DF-CLSM is especially well suited to the task of establishing the spatial localization of nanoparticles within cells, a critical topic in nanotoxicology. This technique has advantages to 2D darkfield microscopy as it visualizes nanoparticles in 3D using confocal microscopy. Use of this technique should aid toxicological studies related to observation of NP interactions with biological endpoints at cellular and subcellular levels. AU - Gibbs-Flournoy, E.A.* AU - Bromberg, P.A.* AU - Hofer, T.P. AU - Samet, J.M.* AU - Zucker, R.M.* C1 - 5473 C2 - 28461 TI - Darkfield-confocal microscopy detection of nanoscale particle internalization by human lung cells. JO - Part. Fibre Toxicol. VL - 8 IS - 1 PB - Biomed Central PY - 2011 SN - 1743-8977 ER - TY - JOUR AB - BACKGROUND: The alveolar macrophage (AM) - first line of innate immune defence against pathogens and environmental irritants - constitutively expresses peroxisome-proliferator activated receptor γ (PPARγ). PPARγ ligand-induced activation keeps the AM quiescent, and thereby contributes to combat invaders and resolve inflammation by augmenting the phagocytosis of apoptotic neutrophils and inhibiting an excessive expression of inflammatory genes. Because of these presumed anti-inflammatory functions of PPARγ we tested the hypothesis, whether reduced functional receptor availability in mutant mice resulted in increased cellular and molecular inflammatory response during acute inflammation and/or in an impairment of its resolution. METHODS: To address this hypothesis we examined the effects of a carbon-nanoparticle (CNP) lung challenge, as surrogate for non-infectious environmental irritants, in a murine model carrying a dominant-negative point mutation in the ligand-binding domain of PPARγ (P465L/wt). Animals were instilled intratracheally with Printex 90 CNPs and bronchoalveolar lavage (BAL) was gained 24 h or 72 h after instillation to investigate its cellular and protein composition. RESULTS: Higher BAL cell numbers - due to higher macrophage counts - were found in mutants irrespective of treatment. Neutrophil numbers in contrast were slightly lower in mutants. Intratracheal CNP instillation resulted in a profound recruitment of inflammatory neutrophils into the alveolus, but genotype related differences at acute inflammation (24 h) and resolution (72 h) were not observed. There were no signs for increased alveolar-capillary membrane damage or necrotic cell death in mutants as determined by BAL protein and lactate-dehydrogenase content. Pro-inflammatory macrophage-derived cytokine osteopontin was higher, but galectin-3 lower in female mutants. CXCL5 and lipocalin-2 markers, attributed to epithelial cell stimulation did not differ. CONCLUSIONS: Despite general genotype-related differences, we had to reject our hypothesis of an increased CNP induced lung inflammation and an impairment of its resolution in PPARγ defective mice. Although earlier studies showed ligand-induced activation of nuclear receptor PPARγ to promote resolution of lung inflammation, its reduced activity did not provide signs of resolution impairment in the settings investigated here. AU - Götz, A.A. AU - Vidal-Puig, A.* AU - Rödel, H.G.* AU - Hrabě de Angelis, M. AU - Stöger, T. C1 - 6703 C2 - 29140 TI - Carbon-nanoparticle-triggered acute lung inflammation and its resolution are not altered in PPARγ-defective (P465L) mice. JO - Part. Fibre Toxicol. VL - 8 PB - BioMed Cental PY - 2011 SN - 1743-8977 ER - TY - JOUR AB - BACKGROUND: Obesity can be linked to disease risks such as diabetes and cardiovascular disorders, but recently, the adipose tissue (AT) macrophage also emerges as actively participating in inflammation and immune function, producing pro- and anti-inflammatory factors. Connections between the AT and chronic lung diseases, like emphysema and asthma and a protective role of adipocyte-derived proteins against acute lung injury were suggested.In this study we addressed the question, whether a diet challenge increases the inflammatory response in the alveolar and the blood compartment in response to carbon nanoparticles (CNP), as a surrogate for ambient/urban particulate air pollutants METHODS: Mice were fed a high caloric carbohydrate-rich (CA) or a fat-rich (HF) diet for six weeks and were compared to mice kept on a purified low fat (LF) diet, respectively. Bronchoalveolar lavage (BAL) and blood samples were taken 24 h after intratracheal CNP instillation and checked for cellular and molecular markers of inflammation. RESULTS AND DISCUSSION: The high caloric diets resulted in distinct effects when compared with LF mice, respectively: CA resulted in increased body and fat mass without affecting blood cellular immunity. Conversely, HF activated the blood system, increasing lymphocyte and neutrophil counts, and resulted in slightly increased body fat content. In contrast to higher pro-inflammatory BAL Leptin in CA and HF mice, on a cellular level, both diets did not lead to an increased pro-inflammatory basal status in the alveolar compartment per se, nor did result in differences in the particle-triggered response. However both diets resulted in a disturbance of the alveolar capillary barrier as indicated by enhanced BAL protein and lactate-dehydrogenase concentrations. Systemically, reduced serum Adiponectin in HF mice might be related to the observed white blood cell increase. CONCLUSION: The increase in BAL pro-inflammatory factors in high caloric groups and reductions in serum concentrations of anti-inflammatory factors in HF mice, clearly show diet-specific effects, pointing towards augmented systemic inflammatory conditions. Our data suggest that extended feeding periods, leading to manifest obesity, are necessary to generate an increased susceptibility to particle-induced lung inflammation; although the diet-challenge already was efficient in driving pro-inflammatory systemic events. AU - Götz, A.A. AU - Rozman, J. AU - Rödel, H.G.* AU - Fuchs, H. AU - Gailus-Durner, V. AU - Hrabě de Angelis, M. AU - Klingenspor, M.* AU - Stöger, T. C1 - 6704 C2 - 29141 TI - Comparison of particle-exposure triggered pulmonary and systemic inflammation in mice fed with three different diets. JO - Part. Fibre Toxicol. VL - 8 PB - BioMed Cental PY - 2011 SN - 1743-8977 ER - TY - JOUR AB - Inhalation of fine particulate matter (<2.5 μm; fine PM) has been shown to increase the risk for cardiovascular events. In this letter, we reappraise the role of tissue factor (TF) antigen and we also summarize changes in measured coagulation proteins in humans and rodents by other studies with fine PM. By considering all studies including ours, we conclude that monitoring the overall coagulation state by measuring capacity assays such as thrombin generation, and quantification of TF activity would be more suitable than determining single coagulation proteins (such as TF antigen) in order to better assess the systemic prothrombotic effects of fine PM. AU - Kilinc, E.* AU - Schulz, S. AU - Kuiper, G.J.* AU - Spronk, H.M.H.* AU - ten Cate, H.* AU - Upadhyay, S.* AU - Ganguly, K.* AU - Stöger, T. AU - Semmler-Behnke, M. AU - Takenaka, S. AU - Kreyling, W.G. AU - Pitz, M. AU - Reitmeir, P. AU - Peters, A. AU - Eickelberg, O. AU - Wichmann, H.-E. C1 - 6300 C2 - 28321 TI - The procoagulant effects of fine particulate matter in vivo. JO - Part. Fibre Toxicol. VL - 8 PB - Biomed Central PY - 2011 SN - 1743-8977 ER - TY - JOUR AB - BACKGROUND: In nanotoxicology, the exact role of particle shape, in relation to the composition, on the capacity to induce toxicity is largely unknown. We investigated the toxic and immunotoxic effects of silver wires (length: 1.5 - 25 μm; diameter 100 - 160 nm), spherical silver nanoparticles (30 nm) and silver microparticles (<45 μm) on alveolar epithelial cells (A549). METHODS: Wires and nanoparticles were synthesized by wet-chemistry methods and extensively characterized. Cell viability and cytotoxicity were assessed and potential immunotoxic effects were investigated. To compare the effects on an activated and a resting immune system, cells were stimulated with rhTNF-α or left untreated. Changes in intracellular free calcium levels were determined using calcium imaging. Finally, ion release from the particles was assessed by ICP-MS and the effects of released ions on cell viability and cytotoxicity were tested. RESULTS: No effects were observed for the spherical particles, whereas the silver wires significantly reduced cell viability and increased LDH release from A549 cells. Cytokine promoter induction and NF-κB activation decreased in a concentration dependent manner similar to the decrease seen in cell viability. In addition, a strong increase of intracellular calcium levels within minutes after addition of wires was observed. This toxicity was not due to free silver ions, since the samples with the highest ion release did not induce toxicity and ion release control experiments with cells treated with pre-incubated medium did not show any effects either. CONCLUSIONS: These data showed that silver wires strongly affect the alveolar epithelial cells, whereas spherical silver particles had no effect. This supports the hypothesis that shape is one of the important factors that determine particle toxicity. AU - Stoehr, L.C.* AU - Gonzalez, E.* AU - Stampfl, A. AU - Casals, E.* AU - Duschl, A.* AU - Puntes, V.* AU - Oostingh, G.J.* C1 - 7296 C2 - 29657 TI - Shape matters: Effects of silver nanospheres and wires on human alveolar epithelial cells. JO - Part. Fibre Toxicol. VL - 8 PB - Biomed Central Ltd. PY - 2011 SN - 1743-8977 ER - TY - JOUR AB - Clara cell protein (CC16), the main secretory product of bronchiolar Clara cells, plays an important protective role in the respiratory tract against oxidative stress and inflammation. The purpose of the study was to investigate the role of elemental carbon ultrafine particles (EC-UFP)-induced oxidative stress on Clara cells and CC16 in a mouse model of allergic lung inflammation.METHODS: Ovalbumin (OVA)-sensitized mice were exposed to EC-UFP (507 microg/m(3) for 24 h) or filtered air immediately prior to allergen challenge and systemically treated with N-acetylcysteine (NAC) or vehicle prior and during EC-UFP inhalation. CC16 was measured up to one week after allergen challenge in bronchoalveolar lavage fluid (BALF) and in serum. The relative expression of CC16 and TNF-alpha mRNA were measured in lung homogenates. A morphometrical analysis of mucus hypersecretion and electron microscopy served to investigate goblet cell metaplasia and Clara cell morphological alterations.RESULTS: In non sensitized mice EC-UFP inhalation caused alterations in CC16 concentration, both at protein and mRNA level, and induced Clara cell hyperplasia. In sensitized mice, inhalation of EC-UFP prior to OVA challenge caused most significant alterations of BALF and serum CC16 concentration, BALF total protein and TNF-alpha relative expression compared to relevant controls; their Clara cells displayed the strongest morphological alterations and strongest goblet cell metaplasia occurred in the small airways. NAC strongly reduced both functional and morphological alterations of Clara cells.CONCLUSION: Our findings demonstrate that oxidative stress AU - Alessandrini, F. AU - Weichenmeier, I. AU - van Miert, E.* AU - Takenaka, S. AU - Karg, E.W. AU - Blume, C. AU - Mempel, M. AU - Schulz, S. AU - Bernard, A.* AU - Behrendt, H. C1 - 3137 C2 - 27887 TI - Effects of ultrafine particles-induced oxidative stress on Clara cells in allergic lung inflammation. JO - Part. Fibre Toxicol. VL - 7 PB - BioMed Central Ltd. PY - 2010 SN - 1743-8977 ER - TY - JOUR AB - Nanotechnology has brought a variety of new possibilities into biological discovery and clinical practice. In particular, nano-scaled carriers have revolutionalized drug delivery, allowing for therapeutic agents to be selectively targeted on an organ, tissue and cell specific level, also minimizing exposure of healthy tissue to drugs. In this review we discuss and analyze three issues, which are considered to be at the core of nano-scaled drug delivery systems, namely functionalization of nanocarriers, delivery to target organs and in vivo imaging. The latest developments on highly specific conjugation strategies that are used to attach biomolecules to the surface of nanoparticles (NP) are first reviewed. Besides drug carrying capabilities, the functionalization of nanocarriers also facilitate their transport to primary target organs. We highlight the leading advantage of nanocarriers, i.e. their ability to cross the blood-brain barrier (BBB), a tightly packed layer of endothelial cells surrounding the brain that prevents high-molecular weight molecules from entering the brain. The BBB has several transport molecules such as growth factors, insulin and transferrin that can potentially increase the efficiency and kinetics of brain-targeting nanocarriers. Potential treatments for common neurological disorders, such as stroke, tumours and Alzheimer's, are therefore a much sought-after application of nanomedicine. Likewise any other drug delivery system, a number of parameters need to be registered once functionalized NPs are administered, for instance their efficiency in organ-selective targeting, bioaccumulation and excretion. Finally, direct in vivo imaging of nanomaterials is an exciting recent field that can provide real-time tracking of those nanocarriers. We review a range of systems suitable for in vivo imaging and monitoring of drug delivery, with an emphasis on most recently introduced molecular imaging modalities based on optical and hybrid contrast, such as fluorescent protein tomography and multispectral optoacoustic tomography. Overall, great potential is foreseen for nanocarriers in medical diagnostics, therapeutics and molecular targeting. A proposed roadmap for ongoing and future research directions is therefore discussed in detail with emphasis on the development of novel approaches for functionalization, targeting and imaging of nano-based drug delivery systems, a cutting-edge technology poised to change the ways medicine is administered. AU - Bhaskar, S.* AU - Tian, F. AU - Stöger, T. AU - Kreyling, W.G. AU - de la Fuente, J.M.* AU - Grazu, V.* AU - Borm, P.* AU - Estrada, G.G. AU - Ntziachristos, V. AU - Razansky, D. C1 - 70 C2 - 27212 TI - Multifunctional Nanocarriers for diagnostics, drug delivery and targeted treatment across blood-brain barrier: Perspectives on tracking and neuroimaging. JO - Part. Fibre Toxicol. VL - 7 PB - Biomed Central Ltd. PY - 2010 SN - 1743-8977 ER - TY - JOUR AB - Particle biokinetics is important in hazard identification and characterization of inhaled particles. Such studies intend to convert external to internal exposure or biologically effective dose, and may help to set limits in that way. Here we focus on the biokinetics of inhaled nanometer sized particles in comparison to micrometer sized ones.The presented approach ranges from inhaled particle deposition probability and retention in the respiratory tract to biokinetics and clearance of particles out of the respiratory tract. Particle transport into the blood circulation (translocation), towards secondary target organs and tissues (accumulation), and out of the body (clearance) is considered. The macroscopically assessed amount of particles in the respiratory tract and secondary target organs provides dose estimates for toxicological studies on the level of the whole organism. Complementary, microscopic analyses at the individual particle level provide detailed information about which cells and subcellular components are the target of inhaled particles. These studies contribute to shed light on mechanisms and modes of action eventually leading to adverse health effects by inhaled nanoparticles.We review current methods for macroscopic and microscopic analyses of particle deposition, retention and clearance. Existing macroscopic knowledge on particle biokinetics and microscopic views on particle organ interactions are discussed comparing nanometer and micrometer sized particles. We emphasize the importance for quantitative analyses and the use of particle doses derived from real world exposures. AU - Geiser, M.* AU - Kreyling, W.G. C1 - 5669 C2 - 27747 TI - Deposition and biokinetics of inhaled nanoparticles. JO - Part. Fibre Toxicol. VL - 7 PB - BioMed Central PY - 2010 SN - 1743-8977 ER - TY - JOUR AB - BACKGROUND AND OBJECTIVE: Exposure to fine airborne particles (PM2.5) has been shown to be responsible for cardiovascular and hematological effects, especially in older people with cardiovascular disease. Some epidemiological studies suggest that individuals with diabetes may be a particularly susceptible population. This study examined effects of short-term exposures to ambient PM2.5 on markers of systemic inflammation, coagulation, autonomic control of heart rate, and repolarization in 22 adults (mean age: 61 years) with type 2 diabetes. METHODS: Each individual was studied for four consecutive days with daily assessments of plasma levels of blood markers. Cardiac rhythm and electrocardiographic parameters were examined at rest and with 24-hour ambulatory ECG monitors. PM2.5 and meteorological data were measured daily on the rooftop of the patient exam site. Data were analyzed with models adjusting for season, weekday, meteorology, and a random intercept. To identify susceptible subgroups, effect modification was analyzed by clinical characteristics associated with insulin resistance as well as with oxidative stress and by medication intake. RESULTS: Interleukin (IL)-6 and tumor necrosis factor alpha showed a significant increase with a lag of two days (percent change of mean level: 20.2% with 95%-confidence interval [6.4; 34.1] and 13.1% [1.9; 24.4], respectively) in association with an increase of 10 mug/m3 in PM2.5. Obese participants as well as individuals with elevated glycosylated hemoglobin, lower adiponectin, higher ferritin or with glutathione S-transferase M1 null genotype showed higher IL-6 effects. Changes in repolarization were found immediately as well as up to four days after exposure in individuals without treatment with a beta-adrenergic receptor blocker. CONCLUSIONS: Exposure to elevated levels of PM2.5 alters ventricular repolarization and thus may increase myocardial vulnerability to arrhythmias. Exposure to PM2.5 also increases systemic inflammation. Characteristics associated with insulin resistance or with oxidative stress were shown to enhance the association. AU - Schneider, A.E. AU - Neas, L.M.* AU - Graff, D.W.* AU - Herbst, M.C. AU - Cascio, W.E.* AU - Schmitt, M.T.* AU - Buse, J.B.* AU - Peters, A. AU - Devlin, R.B.* C1 - 2815 C2 - 27384 TI - Association of cardiac and vascular changes with ambient PM₂.₅ in diabetic individuals. JO - Part. Fibre Toxicol. VL - 7 PB - BioMed Central Ltd. PY - 2010 SN - 1743-8977 ER - TY - JOUR AB - Background and Objective: Exposure to ambient particles has been shown to be responsible for cardiovascular effects, especially in elderly with cardiovascular disease. The study assessed the association between deceleration capacity (DC) as well as heart rate variability (HRV) and ambient particulate matter (PM) in patients with coronary artery disease (CAD). Methods: A prospective study with up to 12 repeated measurements was conducted in Erfurt, Germany, between October 2000 and April 2001 in 56 patients with physician-diagnosed ischemic heart disease, stable angina pectoris or prior myocardial infarction at an age of at least 50 years. Twenty-minute ECG recordings were obtained every two weeks and 24-hour ECG recordings every four weeks. Exposure to PM (size range from 10 nm to 2.5 mu m), and elemental (EC) and organic (OC) carbon was measured. Additive mixed models were used to analyze the association between PM and ECG recordings. Results: The short-term recordings showed decrements in the high-frequency component of HRV as well as in RMSSD (root-mean-square of successive differences of NN intervals) in association with increments in EC and OC 0-23 hours prior to the recordings. The long-term recordings revealed decreased RMSSD and pNN50 (% of adjacent NN intervals that differed more than 50 ms) in association with EC and OC 24-47 hours prior to the recordings. In addition, highly significant effects were found for DC which decreased in association with PM2.5, EC and OC concurrent with the ECG recordings as well as with a lag of up to 47 hours. Conclusions: The analysis showed significant effects of ambient particulate air pollution on DC and HRV parameters reflecting parasympathetic modulation of the heart in patients with CAD. An air pollution-related decrease in parasympathetic tone as well as impaired heart rate deceleration capacity may contribute to an increased risk for cardiac morbidity and sudden cardiac death in vulnerable populations. AU - Schneider, A.E. AU - Hampel, R. AU - Ibald-Mulli, A.* AU - Zareba, W.* AU - Schmidt, G.* AU - Schneider, R.* AU - Rückerl, R. AU - Couderc, J.P.* AU - Mykins, B.* AU - Oberdörster, G.* AU - Wölke, G. AU - Wichmann, H.-E. AU - Peters, A. C1 - 6004 C2 - 27995 CY - London TI - Changes in deceleration capacity of heart rate and heart rate variability induced by ambient air pollution in individuals with coronary artery disease. JO - Part. Fibre Toxicol. VL - 7 PB - Biomed Central Ltd PY - 2010 SN - 1743-8977 ER - TY - JOUR AB - RATIONALE: Several epidemiological studies associated exposure to increased levels of particulate matter in Augsburg, Germany with cardiovascular mortality and morbidity. To elucidate the mechanisms of cardiovascular impairments we investigated the cardiopulmonary responses in spontaneously hypertensive rats (SHR), a model for human cardiovascular diseases, following intratracheal instillation of dust samples from Augsburg. METHODS: 250 μg, 500 μg and 1000 μg of fine ambient particles (aerodynamic diameter <2.5 μm, PM₂(.)₅-AB) collected from an urban background site in Augsburg during September and October 2006 (PM₂(.)₅ 18.2 μg/m³, 10,802 particles/cm3) were instilled in 12 months old SHRs to assess the inflammatory response in bronchoalveolar lavage fluid (BALF), blood, lung and heart tissues 1 and 3 days post instillation. Radio-telemetric analysis was performed to investigate the cardiovascular responses following instillation of particles at the highest dosage based on the inflammatory response observed. RESULTS: Exposure to 1000 μg of PM₂(.)₅-AB was associated with a delayed increase in delta mean blood pressure (ΔmBP) during 2(nd)-4(th) day after instillation (10.0 ± 4.0 vs. -3.9 ± 2.6 mmHg) and reduced heart rate (HR) on the 3rd day post instillation (325.1 ± 8.8 vs. 348.9 ± 12.5 bpm). BALF cell differential and inflammatory markers (osteopontin, interleukin-6, C-reactive protein, and macrophage inflammatory protein-2) from pulmonary and systemic level were significantly induced, mostly in a dose-dependent way. Protein analysis of various markers indicate that PM₂(.)₅-AB instillation results in an activation of endothelin system (endothelin1), renin-angiotensin system (angiotensin converting enzyme) and also coagulation system (tissue factor, plasminogen activator inhibitor-1) in pulmonary and cardiac tissues during the same time period when alternation in ΔmBP and HR have been detectedd. CONCLUSIONS: Our data suggests that high concentrations of PM₂(.)₅-AB exposure triggers low grade PM mediated inflammatory effects in the lungs but disturbs vascular homeostasis in pulmonary tissues and on a systemic level by affecting the renin angiotensin system, the endothelin system and the coagulation cascade. These findings are indicative for promotion of endothelial dysfunction, atherosclerotic lesions, and thrombogeneis and, thus, provide plausible evidence that susceptible-predisposed individuals may develop acute cardiac events like myocardial infarction when repeatedly exposed to high pollution episodes as observed in epidemiological studies in Augsburg, Germany. AU - Upadhyay, S. AU - Ganguly, K. AU - Stöger, T. AU - Semmler-Behnke, M. AU - Takenaka, S. AU - Kreyling, W.G. AU - Pitz, M. AU - Reitmeir, P. AU - Peters, A. AU - Eickelberg, O. AU - Wichmann, H.-E. AU - Schulz, S. C1 - 5988 C2 - 27756 TI - Cardiovascular and inflammatory effects of intratracheally instilled ambient dust from Augsburg, Germany, in spontaneously hypertensive rats (SHRs). JO - Part. Fibre Toxicol. VL - 7 PB - BioMed Central Ltd. PY - 2010 SN - 1743-8977 ER - TY - JOUR AB - BACKGROUND: Ambient particulate matter (PM)-associated metals have been shown to play an important role in cardiopulmonary health outcomes. To study the modulation of PM-induced inflammation by leached off metals, we investigated intracellular solubility of radio-labeled iron oxide ((59)Fe(2)O(3)) particles of 0.5 and 1.5 mum geometric mean diameter. Fe(2)O(3 )particles were examined for the induction of the release of interleukin 6 (IL-6) as pro-inflammatory and prostaglandin E(2 )(PGE(2)) as anti-inflammatory markers in cultured alveolar macrophages (AM) from Wistar Kyoto (WKY) rats. In addition, we exposed male WKY rats to monodispersed Fe(2)O(3 )particles by intratracheal instillation (1.3 or 4.0 mg/kg body weight) to examine in vivo inflammation. RESULTS: Particles of both sizes are insoluble extracellularly in the media but moderately soluble in AM with an intracellular dissolution rate of 0.0037 +/- 0.0014 d(-1 )for 0.5 mum and 0.0016 +/- 0.0012 d(-1 )for 1.5 mum (59)Fe(2)O(3 )particles. AM exposed in vitro to 1.5 mum particles (10 mug/mL) for 24 h increased IL-6 release (1.8-fold; p < 0.05) and also PGE(2 )synthesis (1.9-fold; p < 0.01). By contrast, 0.5 mum particles did not enhance IL-6 release but strongly increased PGE(2 )synthesis (2.5-fold, p < 0.005). Inhibition of PGE(2 )synthesis by indomethacin caused a pro-inflammatory phenotype as noted by increased IL-6 release from AM exposed to 0.5 mum particles (up to 3-fold; p < 0.005). In the rat lungs, 1.5 but not 0.5 mum particles (4.0 mg/kg) induced neutrophil influx and increased vascular permeability. CONCLUSIONS: Fe(2)O(3 )particle-induced neutrophilic inflammatory response in vivo and pro-inflammatory cytokine release in vitro might be modulated by intracellular soluble iron via PGE(2 )synthesis. The suppressive effect of intracellular released soluble iron on particle-induced inflammation has implications on how ambient PM-associated but soluble metals influence pulmonary toxicity of ambient PM. AU - Beck-Speier, I. AU - Kreyling, W.G. AU - Maier, K.L. AU - Dayal, N. AU - Schladweiler, M.C.* AU - Mayer, P. AU - Semmler-Behnke, M. AU - Kodavanti, U.P.* C1 - 320 C2 - 27142 TI - Soluble iron modulates iron oxide particle-induced inflammatory responses via prostaglandin E₂ synthesis: In vitro and in vivo studies. JO - Part. Fibre Toxicol. VL - 6 PB - Biomed Central Ltd PY - 2009 SN - 1743-8977 ER - TY - JOUR AB - Cytochrome P450 monoxygenases play an important role in the defence against inhaled toxic compounds and in metabolizing a wide range of xenobiotics and environmental contaminants. In ambient aerosol the ultrafine particle fraction which penetrates deeply into the lungs is considered to be a major factor for adverse health effects. The cells mainly affected by inhaled particles are lung epithelial cells and cells of the monocyte/macrophage lineage. RESULTS: In this study we have analyzed the effect of a mixture of fine TiO2 and ultrafine carbon black Printex 90 particles (P90) on the expression of cytochrome P450 1B1 (CYP1B1) in human monocytes, macrophages, bronchial epithelial cells and epithelial cell lines. CYP1B1 expression is strongly down-regulated by P90 in monocytes with a maximum after P90 treatment for 3 h while fine and ultrafine TiO2 had no effect. CYP1B1 was down-regulated up to 130-fold and in addition CYP1A1 mRNA was decreased 13-fold. In vitro generated monocyte-derived macrophages (MDM), epithelial cell lines, and primary bronchial epithelial cells also showed reduced CYP1B1 mRNA levels. Benzo[a]pyrene (BaP) is inducing CYB1B1 but ultrafine P90 can still down-regulate gene expression at 0.1 muM of BaP. The P90-induced reduction of CYP1B1 was also demonstrated at the protein level using Western blot analysis. CONCLUSION: These data suggest that the P90-induced reduction of CYP gene expression may interfere with the activation and/or detoxification capabilities of inhaled toxic compounds. AU - Eder, C. AU - Frankenberger, M. AU - Stanzel, F.* AU - Seidel, A.* AU - Schramm, K.-W. AU - Ziegler-Heitbrock, L. AU - Hofer, T.P. C1 - 2060 C2 - 26637 TI - Ultrafine carbon particles down-regulate CYP1B1 expression in human monocytes. JO - Part. Fibre Toxicol. VL - 6 PB - Biomed Central PY - 2009 SN - 1743-8977 ER - TY - JOUR AB - Background: Carbonaceous nanoparticles possess an emerging source of human exposure due to the massive release of combustion products and the ongoing revolution in nanotechnology. Pulmonary inflammation caused by deposited nanoparticles is central for their adverse health effects. Epidemiological studies suggest that individuals with favourable lung physiology are at lower risk for particulate matter associated respiratory diseases probably due to efficient control of inflammation and repair process. Therefore we selected a mouse strain C3H/HeJ (C3) with robust lung physiology and exposed it to moderately toxic carbon nanoparticles (CNP) to study the elicited pulmonary inflammation and its resolution. Methods: 5 mu g, 20 mu g and 50 mu g CNP were intratracheally (i.t.) instilled in C3 mice to identify the optimal dose for subsequent time course studies. Pulmonary inflammation was assessed using histology, bronchoalveolar lavage (BAL) analysis and by a panel of 62 protein markers. Results: 1 day after instillation of CNP, C3 mice exhibited a typical dose response, with the lowest dose (5 mu g) representing the 'no effect level' as reflected by polymorphonuclear leucocyte (PMN), and BAL/lung concentrations of pro-inflammatory proteins. Histological analysis and BAL-protein concentration did not reveal any evidence of tissue injury in 20 mu g CNP instilled animals. Accordingly time course assessment of the inflammatory response was performed after 3 and 7 days with this dose (20 mu g). Compared to day 1, BAL PMN counts were significantly decreased at day 3 and completely returned to normal by day 7. We have identified protein markers related to the acute response and also to the time dependent response in lung and BAL. After complete resolution of PMN influx on day 7, we detected elevated concentrations of 20 markers that included IL1B, IL18, FGF2, EDN1, and VEGF in lung and/or BAL. Biological pathway analysis revealed these factors to be involved in a closely regulated molecular cascade with IL1B/IL18 as upstream and FGF2/EDN1/VEGF as downstream molecules. Conclusion: Considering the role of VEGF, FGF2 and EDN1 in lung development and morphogenesis together with the lack of any evident tissue damage we suggest a protective/homeostatic machinery to be associated in lungs of stable organisms to counter the CNP challenge as a precautionary measure. AU - Ganguly, K. AU - Upadhyay, S. AU - Irmler, M. AU - Takenaka, S. AU - Pukelsheim, K. AU - Beckers, J. AU - Hamelmann, E.* AU - Schulz, S. AU - Stöger, T. C1 - 2955 C2 - 26729 TI - Pathway focused protein profiling indicates differential function for IL-1B,-18 and VEGF during initiation and resolution of lung inflammation evoked by carbon nanoparticle exposure in mice. JO - Part. Fibre Toxicol. VL - 6 PB - Biomed Central Ltd PY - 2009 SN - 1743-8977 ER - TY - JOUR AB - Growing evidence indicates that ambient air pollution is associated with exacerbation of chronic diseases like chronic pulmonary disease. A prospective panel study was conducted to investigate short-term changes of blood markers of inflammation and coagulation in response to daily changes in air pollution in Erfurt, Germany. 12 clinical visits were scheduled and blood parameters were measured in 38 male patients with chronic pulmonary disease during winter 2001/2002. Additive mixed models with random patient intercept were applied, adjusting for trend, weekday, and meteorological parameters. Hourly data on ultrafine particles (UFP, 0.01-0.1 μm), accumulation mode particles (ACP, 0.1-1.0 μm), PM10 (particulate matter <10 μm in diameter), elemental (EC) and organic carbon (OC), gaseous pollutants (nitrogen monoxide [NO], nitrogen dioxide [NO2], carbon monoxide [CO], and sulphur dioxide [SO2]) were collected at a central monitoring site and meteorological data were received from an official network. For each person and visit the individual 24-hour average of pollutants immediately preceding the blood withdrawal (lag 0) up to day 5 (lag1-4) and 5-day running means were calculated. Results: Increased levels of fibrinogen were observed for an increase in one interquartile range of UFP, PM10, EC, OC, CO, and NO revealing the strongest effect for lag 3. E-selectin increased in association with ACP and PM10 with a delay of one day. The ACP effect was also seen with the 5-day-mean. The pattern found for D-dimer was inconsistent. Prothrombin fragment 1+2 decreased with lag 4 consistently for all particulate pollutants. Von Willebrand factor antigen (vWF) showed a consistent decrease in association with almost all air pollutants with all lags except for lag 0. No associations were found for C-reactive protein, soluble intercellular adhesion molecule 1, serum amyloid A and factor VII. Conclusion: These results suggest that elevated concentrations of air pollution are associated with changes in some blood markers of inflammation and coagulation in patients with chronic pulmonary disease. The clinical implications of these findings need further investigation. AU - Hildebrandt, K.* AU - Rückerl, R. AU - Koenig, W.* AU - Schneider, A.E. AU - Pitz, M.* AU - Heinrich, J. AU - Marder, V.* AU - Frampton, M.* AU - Oberdorter, G.* AU - Wichmann, H.-E. AU - Peters, A. C1 - 1863 C2 - 26564 TI - Short-term effects of air pollution: A panel study of blood markers in patients with chronic pulmonary disease. JO - Part. Fibre Toxicol. VL - 6 PB - Biomed Central Ltd PY - 2009 SN - 1743-8977 ER - TY - JOUR AB - Background: Exposure to fine ambient particulate matter (PM) has consistently been associated with increased morbidity and mortality. The relationship between exposure to ultrafine particles (UFP) and health effects is less firmly established. If UFP cause health effects independently from coarser fractions, this could affect health impact assessment of air pollution, which would possibly lead to alternative policy options to be considered to reduce the disease burden of PM. Therefore, we organized an expert elicitation workshop to assess the evidence for a causal relationship between exposure to UFP and health endpoints. Methods: An expert elicitation on the health effects of ambient ultrafine particle exposure was carried out, focusing on: 1) the likelihood of causal relationships with key health endpoints, and 2) the likelihood of potential causal pathways for cardiac events. Based on a systematic peernomination procedure, fourteen European experts (epidemiologists, toxicologists and clinicians) were selected, of whom twelve attended. They were provided with a briefing book containing key literature. After a group discussion, individual expert judgments in the form of ratings of the likelihood of causal relationships and pathways were obtained using a confidence scheme adapted from the one used by the Intergovernmental Panel on Climate Change. Results: The likelihood of an independent causal relationship between increased short-term UFP exposure and increased all-cause mortality, hospital admissions for cardiovascular and respiratory diseases, aggravation of asthma symptoms and lung function decrements was rated medium to high by most experts. The likelihood for long-term UFP exposure to be causally related to all cause mortality, cardiovascular and respiratory morbidity and lung cancer was rated slightly lower, mostly medium. The experts rated the likelihood of each of the six identified possible causal pathways separately. Out of these six, the highest likelihood was rated for the pathway involving respiratory inflammation and subsequent thrombotic effects. Conclusion: The overall medium to high likelihood rating of causality of health effects of UFP exposure and the high likelihood rating of at least one of the proposed causal mechanisms explaining associations between UFP and cardiac events, stresses the importance of considering UFP in future health impact assessments of (transport-related) air pollution, and the need for further research on UFP exposure and health effects. AU - Knol, A.B.* AU - de Hartog, J.J.* AU - Boogaard, H.* AU - Slottje, P.* AU - van der Sluijs, J.P.* AU - Lebret, E.* AU - Cassee, F.R.* AU - Wardekker, A.* AU - Ayres, J.G.* AU - Borm, P.J.* AU - Brunekreef, B.* AU - Donaldson, K.* AU - Forastiere, F.* AU - Holgate, S.T.* AU - Kreyling, W.G. AU - Nemery, B.* AU - Pekkanen, J.* AU - Stone, V.* AU - Wichmann, H.-E. AU - Hoek, G. C1 - 1349 C2 - 26409 TI - Expert elicitation on ultrafine particles: Likelihood of health effects and causal pathways. JO - Part. Fibre Toxicol. VL - 6 PB - Biomed Central Ltd PY - 2009 SN - 1743-8977 ER - TY - JOUR AB - BACKGROUND: Engineered nanoparticles are becoming increasingly ubiquitous and their toxicological effects on human health, as well as on the ecosystem, have become a concern. Since initial contact with nanoparticles occurs at the epithelium in the lungs (or skin, or eyes), in vitro cell studies with nanoparticles require dose-controlled systems for delivery of nanoparticles to epithelial cells cultured at the air-liquid interface. RESULTS: A novel air-liquid interface cell exposure system (ALICE) for nanoparticles in liquids is presented and validated. The ALICE generates a dense cloud of droplets with a vibrating membrane nebulizer and utilizes combined cloud settling and single particle sedimentation for fast (~10 min; entire exposure), repeatable (<12%), low-stress and efficient delivery of nanoparticles, or dissolved substances, to cells cultured at the air-liquid interface. Validation with various types of nanoparticles (Au, ZnO and carbon black nanoparticles) and solutes (such as NaCl) showed that the ALICE provided spatially uniform deposition (<1.6% variability) and had no adverse effect on the viability of a widely used alveolar human epithelial-like cell line (A549). The cell deposited dose can be controlled with a quartz crystal microbalance (QCM) over a dynamic range of at least 0.02-200 mug/cm(2). The cell-specific deposition efficiency is currently limited to 0.072 (7.2% for two commercially available 6-er transwell plates), but a deposition efficiency of up to 0.57 (57%) is possible for better cell coverage of the exposure chamber. Dose-response measurements with ZnO nanoparticles (0.3-8.5 mug/cm(2)) showed significant differences in mRNA expression of pro-inflammatory (IL-8) and oxidative stress (HO-1) markers when comparing submerged and air-liquid interface exposures. Both exposure methods showed no cellular response below 1 mug/cm(2 )ZnO, which indicates that ZnO nanoparticles are not toxic at occupationally allowed exposure levels. CONCLUSION: The ALICE is a useful tool for dose-controlled nanoparticle (or solute) exposure of cells at the air-liquid interface. Significant differences between cellular response after ZnO nanoparticle exposure under submerged and air-liquid interface conditions suggest that pharmaceutical and toxicological studies with inhaled (nano-)particles should be performed under the more realistic air-liquid interface, rather than submerged cell conditions. AU - Lenz, A.-G. AU - Karg, E.W. AU - Lentner, B. AU - Dittrich, V. AU - Brandenberger, C.* AU - Rothen-Rutishauser, B.* AU - Schulz, S. AU - Ferron, G.A. AU - Schmid, O. C1 - 1042 C2 - 27184 TI - A dose-controlled system for air-liquid interface cell exposure and application to zinc oxide nanoparticles. JO - Part. Fibre Toxicol. VL - 6 PB - BioMed Central Ltd. PY - 2009 SN - 1743-8977 ER - TY - JOUR AB - Background: Exposure to particulate matter is a risk factor for cardiopulmonary disease but the underlying molecular mechanisms remain poorly understood. In the present study we sought to investigate the cardiopulmonary responses on spontaneously hypertensive rats (SHRs) following inhalation of UfCPs (24 h, 172 mug.m-3), to assess whether compromised animals (SHR) exhibit a different response pattern compared to the previously studied healthy rats (WKY). Methods: Cardiophysiological response in SHRs was analyzed using radiotelemetry. Blood pressure (BP) and its biomarkers plasma renin-angiotensin system were also assessed. Lung and cardiac mRNA expressions for markers of oxidative stress (hemeoxygenase-1), blood coagulation (tissue factor, plasminogen activator inhibitor-1), and endothelial function (endothelin-1, and endothelin receptors A and B) were analyzed following UfCPs exposure in SHRs. UfCPs-mediated inflammatory responses were assessed from broncho-alveolar-lavage fluid (BALF). Results: Increased BP and heart rate (HR) by about 5% with a lag of 1-3 days were detected in UfCPs exposed SHRs. Inflammatory markers of BALF, lung (pulmonary) and blood (systemic) were not affected. However, mRNA expression of hemeoxygenase-1, endothelin-1, endothelin receptors A and B, tissue factor, and plasminogen activator inhibitor showed a significant induction (~2.5-fold; p < 0.05) with endothelin-1 being the maximally induced factor (6-fold; p < 0.05) on the third recovery day in the lungs of UfCPs exposed SHRs; while all of these factors - except hemeoxygenase-1 - were not affected in cardiac tissues. Strikingly, the UfCPs-mediated altered BP is paralleled by the induction of renin-angiotensin system in plasma. Conclusion: Our finding shows that UfCPs exposure at levels which does not induce detectable pulmonary neutrophilic inflammation, triggers distinct effects in the lung and also at the systemic level in compromised SHRs. These effects are characterized by increased activity of plasma renin-angiotensin system and circulating white blood cells together with moderate increases in the BP, HR and decreases in heart rate variability. This systemic effect is associated with pulmonary, but not cardiac, mRNA induction of biomarkers reflective of oxidative stress; activation of vasoconstriction, stimulation of blood coagulation factors, and inhibition of fibrinolysis. Thus, UfCPs may cause cardiovascular and pulmonary impairment, in the absence of detectable pulmonary inflammation, in individuals suffering from preexisting cardiovascular diseases. AU - Upadhyay, S. AU - Stöger, T. AU - Harder, V. AU - Thomas, R.F.* AU - Schladweiler, M.C.* AU - Semmler-Behnke, M. AU - Takenaka, S. AU - Karg, E.W. AU - Reitmeir, P. AU - Bader, M.* AU - Stampfl, A. AU - Kodavanti, U.P.* AU - Schulz, S. C1 - 2213 C2 - 25985 TI - Exposure to ultrafine carbon particles at levels below detectable pulmonary inflammation affects cardiovascular performance in spontaneously hypertensive rats. JO - Part. Fibre Toxicol. VL - 5 PB - BioMed Central PY - 2008 SN - 1743-8977 ER - TY - JOUR AB - Epidemiological studies on health effects of air pollution have consistently shown adverse cardiovascular effects. Toxicological studies have provided evidence for thrombogenic effects of particles.A prospective panel study in a susceptible population was conducted in Erfurt, Germany, to study the effects of daily changes in ambient particles on various blood cells and soluble CD40ligand (sCD40L, also known as CD154), a marker for platelet activation that can cause increased coagulation and inflammation.Blood cells and plasma sCD40L levels were repeatedly measured in 57 male patients with coronary heart disease (CHD) during winter 2000/2001. Fixed effects linear regression models were applied, adjusting for trend, weekday and meteorological parameters.Hourly data on ultrafine particles (UFP, number concentration of particles from 0.01 to 0.1 mum), mass concentration of particles less than 10 and 2.5 mum in diameter (PM10, PM2.5), accumulation mode particle counts (AP, 0.1-1.0 mum), elemental and organic carbon, gaseous pollutants and meteorological data were collected at central monitoring sites. RESULTS: An immediate increase in plasma sCD40L was found in association with UFP and AP (% change from geometric mean: 7.1; CI: [0.1, 14.5] and 6.9; CI: [0.5, 13.8], respectively). Platelet counts decreased in association with UFP showing an immediate, a three days delayed (lag 3) and a 5-day average response (% change from the mean: -1.8; CI: [-3.4,-0.2]; -2.4; CI: [-4.5,-0.3] and -2.2; CI: [-4.0,-0.3] respectively). CONCLUSION: The increased plasma sCD40L levels support the hypothesis that higher levels of ambient air pollution lead to an inflammatory response in patients with CHD thus providing a possible explanation for the observed association between air pollution and cardiovascular morbidity and mortality in susceptible parts of the population. AU - Rückerl, R. AU - Phipps, R.P.* AU - Schneider, A.E. AU - Frampton, M.* AU - Cyrys, J. AU - Oberdörster, G.* AU - Wichmann, H.-E. AU - Peters, A. C1 - 5192 C2 - 24440 TI - Ultrafine particles and platelet activation in patients with coronary heart disease - results from a prospective panel study. JO - Part. Fibre Toxicol. VL - 4 PB - BioMed Central PY - 2007 SN - 1743-8977 ER - TY - JOUR AB - During the last few years, research on toxicologically relevant properties of engineered nanoparticles has increased tremendously. A number of international research projects and additional activities are ongoing in the EU and the US, nourishing the expectation that more relevant technical and toxicological data will be published. Their widespread use allows for potential exposure to engineered nanoparticles during the whole lifecycle of a variety of products. When looking at possible exposure routes for manufactured Nanoparticles, inhalation, dermal and oral exposure are the most obvious, depending on the type of product in which Nanoparticles are used. This review shows that (1) Nanoparticles can deposit in the respiratory tract after inhalation. For a number of nanoparticles, oxidative stress-related inflammatory reactions have been observed. Tumour-related effects have only been observed in rats, and might be related to overload conditions. There are also a few reports that indicate uptake of nanoparticles in the brain via the olfactory epithelium. Nanoparticle translocation into the systemic circulation may occur after inhalation but conflicting evidence is present on the extent of translocation. These findings urge the need for additional studies to further elucidate these findings and to characterize the physiological impact. (2) There is currently little evidence from skin penetration studies that dermal applications of metal oxide nanoparticles used in sunscreens lead to systemic exposure. However, the question has been raised whether the usual testing with healthy, intact skin will be sufficient. (3) Uptake of nanoparticles in the gastrointestinal tract after oral uptake is a known phenomenon, of which use is intentionally made in the design of food and pharmacological components. Finally, this review indicates that only few specific nanoparticles have been investigated in a limited number of test systems and extrapolation of this data to other materials is not possible. Air pollution studies have generated indirect evidence for the role of combustion derived nanoparticles (CDNP) in driving adverse health effects in susceptible groups. Experimental studies with some bulk nanoparticles (carbon black, titanium dioxide, iron oxides) that have been used for decades suggest various adverse effects. However, engineered nanomaterials with new chemical and physical properties are being produced constantly and the toxicity of these is unknown. Therefore, despite the existing database on nanoparticles, no blanket statements about human toxicity can be given at this time. In addition, limited ecotoxicological data for nanomaterials precludes a systematic assessment of the impact of Nanoparticles on ecosystems. AU - Borm, P.J.* AU - Robbins, D.* AU - Haubold, S.* AU - Kuhlbusch, T.* AU - Fissan, H.* AU - Donaldson, K.* AU - Schins, R.* AU - Stone, V.* AU - Kreyling, W.G. AU - Lademann, J.* AU - Krutmann, J.* AU - Warheit, D.* AU - Oberdorster, E. C1 - 4222 C2 - 23905 TI - The potential risks of nanomaterials: A review carried out for ECETOC. JO - Part. Fibre Toxicol. VL - 3 PB - BioMed Central PY - 2006 SN - 1743-8977 ER - TY - JOUR AB - Particulate air pollution has been associated with respiratory and cardiovascular disease. Evidence for cardiovascular and neurodegenerative effects of ambient particles was reviewed as part of a workshop. The purpose of this critical update is to summarize the evidence presented for the mechanisms involved in the translocation of particles from the lung to other organs and to highlight the potential of particles to cause neurodegenerative effects. Fine and ultrafine particles, after deposition on the surfactant film at the air-liquid interface, are displaced by surface forces exerted on them by surfactant film and may then interact with primary target cells upon this displacement. Ultrafine and fine particles can then penetrate through the different tissue compartments of the lungs and eventually reach the capillaries and circulating cells or constituents, e.g. erythrocytes. These particles are then translocated by the circulation to other organs including the liver, the spleen, the kidneys, the heart and the brain, where they may be deposited. It remains to be shown by which mechanisms ultrafine particles penetrate through pulmonary tissue and enter capillaries. In addition to translocation of ultrafine particles through the tissue, fine and coarse particles may be phagocytized by macrophages and dendritic cells which may carry the particles to lymph nodes in the lung or to those closely associated with the lungs. There is the potential for neurodegenerative consequence of particle entry to the brain. Histological evidence of neurodegeneration has been reported in both canine and human brains exposed to high ambient PM levels, suggesting the potential for neurotoxic consequences of PM-CNS entry. PM mediated damage may be caused by the oxidative stress pathway. Thus, oxidative stress due to nutrition, age, genetics among others may increase the susceptibility for neurodegenerative diseases. The relationship between PM exposure and CNS degeneration can also be detected under controlled experimental conditions. Transgenic mice (Apo E -/-), known to have high base line levels of oxidative stress, were exposed by inhalation to well characterized, concentrated ambient air pollution. Morphometric analysis of the CNS indicated unequivocally that the brain is a critical target for PM exposure and implicated oxidative stress as a predisposing factor that links PM exposure and susceptibility to neurodegeneration. Together, these data present evidence for potential translocation of ambient particles on organs distant from the lung and the neurodegenerative consequences of exposure to air pollutants.   AU - Peters, A. AU - Veronesi, B.* AU - Calderon-Garciduenas, L.* AU - Gehr, P.* AU - Chen, L.C.* AU - Geiser, M.* AU - Reed, B.* AU - Rothen-Rutishauser, B.* AU - Schürch, S.* AU - Schulz, S. C1 - 4298 C2 - 23908 TI - Translocation and potential neurological effects of fine and ultrafine particles a critical update. JO - Part. Fibre Toxicol. VL - 3 PB - BioMed Central PY - 2006 SN - 1743-8977 ER - TY - JOUR AB - Background Translocation of ultrafine particles (UFP) into the blood that returns from the lungs to the heart has been forwarded as a mechanism for particle-induced cardiovascular effects. The objective of this study was to evaluate the role of the endothelial barrier in the translocation of inhaled UFP from the lung into circulation. Methods The isolated perfused rat lung (IPRL) was used under negative pressure ventilation, and radioactive iridium particles (18 nm, CMD, 192Ir-UFP) were inhaled during 60 minutes to achieve a lung burden of 100 – 200 μg. Particle inhalation was done under following treatments: i) control perfusion, ii) histamine (1 μM in perfusate, iii) luminal histamine instillation (1 mM), and iv) luminal instillation of H2O2. Particle translocation to the perfusate was assessed by the radioactivity of 192Ir isotope. Lung permeability by the use of Tc99m-labeled diethylene triamine pentaacetic acid (DTPA). In addition to light microscopic morphological evaluation of fixed lungs, alkaline phosphatase (AKP) and angiotensin converting enzyme (ACE) in perfusate were measured to assess epithelial and endothelial integrity. Results Particle distribution in the lung was homogenous and similar to in vivo conditions. No translocation of Ir particles at negative pressure inhalation was detected in control IPL, but lungs pretreated with histamine (1 μM) in the perfusate or with luminal H2O2 (0.5 mM) showed small amounts of radioactivity (2–3 % dose) in the single pass perfusate starting at 60 min of perfusion. Although the kinetics of particle translocation were different from permeability for 99mTc-DTPA, the pretreatments (H2O2, vascular histamine) caused similar changes in the translocation of particles and soluble mediator. Increased translocation through epithelium and endothelium with a lag time of one hour occurred in the absence of epithelial and endothelial damage. Conclusion Permeability of the lung barrier to UFP or nanoparticles is controlled both at the epithelial and endothelial level. Conditions that affect this barrier function such as inflammation may affect translocation of NP.   AU - Meiring, J.J.* AU - Borm, P.J.A.* AU - Bagate, K.* AU - Semmler, M. AU - Seitz, J. AU - Takenaka, S. AU - Kreyling, W.G. C1 - 3087 C2 - 22759 TI - The influence of hydrogen peroxide and histamine on lung permeability and translocation of iridium nanoparticles in the isolated perfused rat lung. JO - Part. Fibre Toxicol. VL - 2 PB - BioMed Central PY - 2005 SN - 1743-8977 ER - TY - JOUR AB - Background Particulate air pollution is reported to cause adverse health effects in susceptible individuals. Since most of these particles are derived form combustion processes, the primary composition product is carbon with a very small diameter (ultrafine, less than 100 nm in diameter). Besides the induction of reactive oxygen species and inflammation, ultrafine particles (UFP) can cause intracellular calcium transients and suppression of defense mechanisms of alveolar macrophages, such as impaired migration or phagocytosis. Methods In this study the role of intracellular calcium transients caused by UFP was studied on cytoskeleton related functions in J774A.1 macrophages. Different types of fine and ultrafine carbon black particles (CB and ufCB, respectively), such as elemental carbon (EC90), commercial carbon (Printex 90), diesel particulate matter (DEP) and urban dust (UD), were investigated. Phagosome transport mechanisms and mechanical cytoskeletal integrity were studied by cytomagnetometry and cell viability was studied by fluorescence microscopy. Macrophages were exposed in vitro with 100 and 320 μg UFP/ml/million cells for 4 hours in serum free medium. Calcium antagonists Verapamil, BAPTA-AM and W-7 were used to block calcium channels in the membrane, to chelate intracellular calcium or to inhibit the calmodulin signaling pathways, respectively. Results Impaired phagosome transport and increased cytoskeletal stiffness occurred at EC90 and P90 concentrations of 100 μg/ml/million cells and above, but not with DEP or UD. Verapamil and W-7, but not BAPTA-AM inhibited the cytoskeletal dysfunctions caused by EC90 or P90. Additionally the presence of 5% serum or 1% bovine serum albumin (BSA) suppressed the cytoskeletal dysfunctions. Cell viability showed similar results, where co-culture of ufCB together with Verapamil, W-7, FCS or BSA produced less cell dead compared to the particles only.   AU - Möller, W. AU - Brown, D.M.* AU - Kreyling, W.G. AU - Stone, V.* C1 - 3737 C2 - 22883 TI - Ultrafibe particles cause cytoskeletal dysfunctions in macrophages: Role of intracellular calcium. JO - Part. Fibre Toxicol. VL - 2 PB - BioMed Central PY - 2005 SN - 1743-8977 ER - TY - JOUR AB - The rapid proliferation of many different engineered nanomaterials (defined as materials designed and produced to have structural features with at least one dimension of 100 nanometers or less) presents a dilemma to regulators regarding hazard identification. The International Life Sciences Institute Research Foundation/Risk Science Institute convened an expert working group to develop a screening strategy for the hazard identification of engineered nanomaterials. The working group report presents the elements of a screening strategy rather than a detailed testing protocol. Based on an evaluation of the limited data currently available, the report presents a broad data gathering strategy applicable to this early stage in the development of a risk assessment process for nanomaterials. Oral, dermal, inhalation, and injection routes of exposure are included recognizing that, depending on use patterns, exposure to nanomaterials may occur by any of these routes. The three key elements of the toxicity screening strategy are: Physicochemical Characteristics, In Vitro Assays (cellular and non-cellular), and In Vivo Assays. There is a strong likelihood that biological activity of nanoparticles will depend on physicochemical parameters not routinely considered in toxicity screening studies. Physicochemical properties that may be important in understanding the toxic effects of test materials include particle size and size distribution, agglomeration state, shape, crystal structure, chemical composition, surface area, surface chemistry, surface charge, and porosity. In vitro techniques allow specific biological and mechanistic pathways to be isolated and tested under controlled conditions, in ways that are not feasible in in vivo tests. Tests are suggested for portal-of-entry toxicity for lungs, skin, and the mucosal membranes, and target organ toxicity for endothelium, blood, spleen, liver, nervous system, heart, and kidney. Non-cellular assessment of nanoparticle durability, protein interactions, complement activation, and pro-oxidant activity is also considered. Tier 1 in vivo assays are proposed for pulmonary, oral, skin and injection exposures, and Tier 2 evaluations for pulmonary exposures are also proposed. Tier 1 evaluations include markers of inflammation, oxidant stress, and cell proliferation in portal-of-entry and selected remote organs and tissues. Tier 2 evaluations for pulmonary exposures could include deposition, translocation, and toxicokinetics and biopersistence studies; effects of multiple exposures; potential effects on the reproductive system, placenta, and fetus; alternative animal models; and mechanistic studies.   AU - Oberdörster, G.* AU - Maynard, A.* AU - Donaldson, K.* AU - Castranova, V.* AU - Fitzpatrick, J.* AU - Ausman, K.* AU - Carter, J.* AU - Karn, B.* AU - Kreyling, W.G. AU - Lai, D.* AU - Olin, S.* AU - Monteiro-Riviere, N.* AU - Warheit, D.* AU - Yang, H.* AU - ILSI Research Foundation (*) C1 - 3167 C2 - 23040 TI - Principles for characterizing the potential human health effects from exposure to nanomaterials: Elements of a screening strategy. JO - Part. Fibre Toxicol. VL - 2 PB - BioMed Central PY - 2005 SN - 1743-8977 ER -