Hepatic toxicity assessment of cationic liposome exposure in healthy and chronic alcohol fed mice

The utilisation of nanoparticles as the means of targeted delivery of therapeutics and/or imaging agents could greatly enhance the specific transport of biologically active payloads to target tissues while avoiding or reducing undesired side-effects. To allow for this to become a reality, the question of potential toxicological effects needs to be addressed. In the present investigation, a cationic liposome with prospective for medical applications was constructed and thoroughly assessed for any material-induced hepatic adverse effects in vivo − in healthy and alcoholic hepatic disease models and in vitro − (HepG2 cells). The data demonstrated that intravenous injection of liposomes did not cause any significant in vivo hepatic toxicity (inflammation, alterations in blood parameters, anti-oxidant depletion, acute phase response and histopathology) at doses of 200 μg per mouse in either healthy or chronically alcohol fed mice. Additionally, the in vitro material-induced adverse effects (cytotoxicity, inflammation or albumin secretion) were all also minimal. The data from this study demonstrated that the intravenous injection of cationic liposomes does not cause hepatic toxicity. This investigation is important as it investigates the toxicity of a nano-sized material in a model of alcoholic hepatic disease in vitro and in vivo. This is an area of research in the field of nanotoxicology that is currently almost entirely overlooked. Keywords: Toxicology, Nanoparticles, Pharmaceutical scienc

Modest vasomotor dysfunction induced by low doses of C60 fullerenes in apolipoprotein E knockout mice with different degree of atherosclerosis

<p>Abstract</p> <p>Background</p> <p>Exposure to small size particulate matter in urban air is regarded as a risk factor for cardiovascular effects, whereas there is little information about the impact on the cardiovascular system by exposure to pure carbonaceous materials in the nano-size range. C₆₀fullerenes are nano-sized particles that are expected to have a widespread use, including cosmetics and medicines.</p> <p>Methods</p> <p>We investigated the association between intraperitoneal injection of pristine C₆₀fullerenes and vasomotor dysfunction in the aorta of 11–13 and 40–42 weeks old apolipoprotein E knockout mice (apoE^-/-) with different degree of atherosclerosis.</p> <p>Results</p> <p>The aged apoE^-/-mice had lower endothelium-dependent vasorelaxation elicited by acetylcholine in aorta segments mounted in myographs and the phenylephrine-dependent vasoconstriction response was increased. One hour after an intraperitoneal injection of 0.05 or 0.5 mg/kg of C₆₀fullerenes, the young apoE^-/-mice had slightly reduced maximal endothelium-dependent vasorelaxation. A similar tendency was observed in the old apoE^-/-mice. Hampered endothelium-independent vasorelaxation was also observed as slightly increased EC₅₀of sodium nitroprusside-induced vasorelaxation response in young apoE^-/-mice.</p> <p>Conclusion</p> <p>Treatment with C₆₀fullerenes affected mainly the response to vasorelaxation in young apoE^-/-mice, whereas the vasomotor dysfunction in old apoE^-/-mice with more advanced atherosclerosis was less affected by acute C₆₀fullerene treatment. These findings represent an important step in the hazard characterization of C₆₀fullerenes by showing that intraperitoneal administration is associated with a moderate decrease in the vascular function of mice with atherosclerosis.</p

Pulmonary exposure to carbon black nanoparticles and vascular effects

<p>Abstract</p> <p>Background</p> <p>Exposure to small size particulates is regarded as a risk factor for cardiovascular diseases.</p> <p>Methods</p> <p>We exposed young and aged apolipoprotein E knockout mice (<it>apoE^-/-</it>) to carbon black (Printex 90, 14 nm) by intratracheal instillation, with different dosing and timing, and measured vasomotor function, progression of atherosclerotic plaques, and VCAM-1, ICAM-1, and 3-nitrotyrosine in blood vessels. The mRNA expression of <it>VCAM-1</it>, <it>ICAM-1</it>, <it>HO-1</it>, and <it>MCP-1 </it>was examined in lung tissue.</p> <p>Results</p> <p>Young <it>apoE^-/-</it>mice exposed to two consecutive 0.5 mg/kg doses of carbon black exhibited lower acetylcholine-induced vasorelaxation in aorta segments mounted in myographs, whereas single doses of 0.05-2.7 mg/kg produced no such effects. The phenylephrine-dependent vasocontraction response was shifted toward a lower responsiveness in the mice exposed once to a low dose for 24 hours. No effects were seen on the progression of atherosclerotic plaques in the aged <it>apoE^-/-</it>mice or on the expression of VCAM-1 and ICAM-1 and the presence of 3-nitrotyrosine in the vascular tissue of either young or aged <it>apoE^-/-</it>mice. The expression of <it>MCP-1 </it>mRNA was increased in the lungs of young <it>apoE^-/-</it>mice exposed to 0.9-2.7 mg/kg carbon black for 24 hours and of aged <it>apoE^-/-</it>mice exposed to two consecutive 0.5 mg/kg doses of carbon black seven and five weeks prior to sacrifice.</p> <p>Conclusion</p> <p>Exposure to nano-sized carbon black particles is associated with modest vasomotor impairment, which is associated neither with nitrosative stress nor with any obvious increases in the expression of cell adhesion proteins on endothelial cells or in plaque progression. Evidence of pulmonary inflammation was observed, but only in animals exposed to higher doses.</p

Acute hazard assessment of silver nanoparticles following intratracheal instillation, oral and intravenous injection exposures.

With ever-increasing production and use of nanoparticles (NPs), there is a necessity to evaluate the probability of consequential adverse effects in individuals exposed to these particles. It is now understood that a proportion of NPs can translocate from primary sites of exposure to a range of secondary organs, with the liver, kidneys and spleen being some of the most important. In this study, we carried out a comprehensive toxicological profiling (inflammation, changes in serum biochemistry, oxidative stress, acute phase response and histopathology) of Ag NP induced adverse effects in the three organs of interest following acute exposure of the materials at identical doses via intravenous (IV), intratracheal (IT) instillation and oral administration. The data clearly demonstrated that bioaccumulation and toxicity of the particles were most significant following the IV route of exposure, followed by IT. However, oral exposure to the NPs did not result in any changes that could be interpreted as toxicity in any of the organs of interest within the confines of this investigation. The finding of this study clearly indicates the importance of the route of exposure in secondary organ hazard assessment for NPs. Finally, we identify Connexin 32 (Cx32) as a novel biomarker of NP-mediated hepatic damage which is quantifiable both (in vitro) and in vivo following exposure of physiologically relevant doses.This work has been financially supported by SULSA and H2020 funded project PATROLS [Grant code – 760813]. NRJ received funding from FFIKA, Focused Research Effort on Chemicals in the Working Environment, from the Danish Government

Cytokine expression in mice exposed to diesel exhaust particles by inhalation. Role of tumor necrosis factor

BACKGROUND: Particulate air pollution has been associated with lung and cardiovascular disease, for which lung inflammation may be a driving mechanism. The pro-inflammatory cytokine, tumor necrosis factor (TNF) has been suggested to have a key-role in particle-induced inflammation. We studied the time course of gene expression of inflammatory markers in the lungs of wild type mice and Tnf-/- mice after exposure to diesel exhaust particles (DEPs). Mice were exposed to either a single or multiple doses of DEP by inhalation. We measured the mRNA level of the cytokines Tnf and interleukin-6 (Il-6) and the chemokines, monocyte chemoattractant protein (Mcp-1), macrophage inflammatory protein-2 (Mip-2) and keratinocyte derived chemokine (Kc) in the lung tissue at different time points after exposure. RESULTS: Tnf mRNA expression levels increased late after DEP-inhalation, whereas the expression levels of Il-6, Mcp-1 and Kc increased early. The expression of Mip-2 was independent of TNF if the dose was above a certain level. The expression levels of the cytokines Kc, Mcp-1 and Il-6, were increased in the absence of TNF. CONCLUSION: Our data demonstrate that Tnf is not important in early DEP induced inflammation and rather exerts negative influence on Mcp-1 and Kc mRNA levels. This suggests that other signalling pathways are important, a candidate being one involving Mcp-1

Modest effect on plaque progression and vasodilatory function in atherosclerosis-prone mice exposed to nanosized TiO2

<p>Abstract</p> <p>Background</p> <p>There is growing evidence that exposure to small size particulate matter increases the risk of developing cardiovascular disease.</p> <p>Methods</p> <p>We investigated plaque progression and vasodilatory function in apolipoprotein E knockout (<it>ApoE</it>^-/-) mice exposed to TiO₂. <it>ApoE</it>^-/-mice were intratracheally instilled (0.5 mg/kg bodyweight) with rutile fine TiO₂(fTiO₂, 288 nm), photocatalytic 92/8 anatase/rutile TiO₂(pTiO₂, 12 nm), or rutile nano TiO₂(nTiO₂, 21.6 nm) at 26 and 2 hours before measurement of vasodilatory function in aorta segments mounted in myographs. The progression of atherosclerotic plaques in aorta was assessed in mice exposed to nanosized TiO₂(0.5 mg/kg bodyweight) once a week for 4 weeks. We measured mRNA levels of <it>Mcp-1</it>, <it>Mip-2</it>, <it>Vcam-1</it>, <it>Icam-1 </it>and <it>Vegf </it>in lung tissue to assess pulmonary inflammation and vascular function. TiO₂-induced alterations in nitric oxide (NO) production were assessed in human umbilical vein endothelial cells (HUVECs).</p> <p>Results</p> <p>The exposure to nTiO₂was associated with a modest increase in plaque progression in aorta, whereas there were unaltered vasodilatory function and expression levels of <it>Mcp-1</it>, <it>Mip-2</it>, <it>Vcam-1</it>, <it>Icam-1 </it>and <it>Vegf </it>in lung tissue. The <it>ApoE^-/-</it>mice exposed to fine and photocatalytic TiO₂had unaltered vasodilatory function and lung tissue inflammatory gene expression. The unaltered NO-dependent vasodilatory function was supported by observations in HUVECs where the NO production was only increased by exposure to nTiO₂.</p> <p>Conclusion</p> <p>Repeated exposure to nanosized TiO₂particles was associated with modest plaque progression in <it>ApoE^-/-</it>mice. There were no associations between the pulmonary TiO₂exposure and inflammation or vasodilatory dysfunction.</p

Surface modification does not influence the genotoxic and inflammatory effects of TiO₂ nanoparticles after pulmonary exposure by instillation in mice

The influence of surface charge of nanomaterials on toxicological effects is not yet fully understood. We investigated the inflammatory response, the acute phase response and the genotoxic effect of two different titanium dioxide nanoparticles (TiO(2) NPs) following a single intratracheal instillation. NRCWE-001 was unmodified rutile TiO(2) with endogenous negative surface charge, whereas NRCWE-002 was surface modified to be positively charged. C57BL/6J BomTac mice received 18, 54 and 162 µg/mouse and were humanely killed 1, 3 and 28 days post-exposure. Vehicle controls were tested alongside for comparison. The cellular composition and protein concentration were determined in bronchoalveolar lavage (BAL) fluid as markers for an inflammatory response. Pulmonary and systemic genotoxicity was analysed by the alkaline comet assay as DNA strand breaks in BAL cells, lung and liver tissue. The pulmonary and hepatic acute phase response was analysed by Saa3 mRNA levels in lung tissue or Saa1 mRNA levels in liver tissue by real-time quantitative polymerase chain reaction. Instillation of NRCWE-001 and -002 both induced a dose-dependent neutrophil influx into the lung lining fluid and Saa3 mRNA levels in lung tissue at all assessed time points. There was no statistically significant difference between NRCWE-001 and NRCWE-002. Exposure to both TiO(2) NPs induced increased levels of DNA strand breaks in lung tissue at all doses 1 and 28 days post-exposure and NRCWE-002 at the low and middle dose 3 days post-exposure. The DNA strand break levels were statistically significantly different for NRCWE-001 and -002 for liver and for BAL cells, but no consistent pattern was observed. In conclusion, functionalisation of reactive negatively charged rutile TiO(2) to positively charged did not consistently influence pulmonary toxicity of the studied TiO(2) NPs

Particle-induced pulmonary acute phase response may be the causal link between particle inhalation and cardiovascular disease

Inhalation of ambient and workplace particulate air pollution is associated with increased risk of cardiovascular disease. One proposed mechanism for this association is that pulmonary inflammation induces a hepatic acute phase response, which increases risk of cardiovascular disease. Induction of the acute phase response is intimately linked to risk of cardiovascular disease as shown in both epidemiological and animal studies. Indeed, blood levels of acute phase proteins, such as C-reactive protein and serum amyloid A, are independent predictors of risk of cardiovascular disease in prospective epidemiological studies. In this review, we present and review emerging evidence that inhalation of particles (e.g., air diesel exhaust particles and nanoparticles) induces a pulmonary acute phase response, and propose that this induction constitutes the causal link between particle inhalation and risk of cardiovascular disease. Increased levels of acute phase mRNA and proteins in lung tissues, bronchoalveolar lavage fluid and plasma clearly indicate pulmonary acute phase response following pulmonary deposition of different kinds of particles including diesel exhaust particles, nanoparticles, and carbon nanotubes. The pulmonary acute phase response is dose-dependent and long lasting. Conversely, the hepatic acute phase response is reduced relative to lung or entirely absent. We also provide evidence that pulmonary inflammation, as measured by neutrophil influx, is a predictor of the acute phase response and that the total surface area of deposited particles correlates with the pulmonary acute phase response. We discuss the implications of these findings in relation to occupational exposure to nanoparticles. How to cite this article: WIREs Nanomed Nanobiotechnol 2014, 6:517–531. doi: 10.1002/wnan.127

Pulmonary instillation of low doses of titanium dioxide nanoparticles in mice leads to particle retention and gene expression changes in the absence of inflammation

AbstractWe investigated gene expression, protein synthesis, and particle retention in mouse lungs following intratracheal instillation of varying doses of nano-sized titanium dioxide (nano-TiO2). Female C57BL/6 mice were exposed to rutile nano-TiO2 via single intratracheal instillations of 18, 54, and 162μg/mouse. Mice were sampled 1, 3, and 28days post-exposure. The deposition of nano-TiO2 in the lungs was assessed using nanoscale hyperspectral microscopy. Biological responses in the pulmonary system were analyzed using DNA microarrays, pathway-specific real-time RT-PCR (qPCR), gene-specific qPCR arrays, and tissue protein ELISA. Hyperspectral mapping showed dose-dependent retention of nano-TiO2 in the lungs up to 28days post-instillation. DNA microarray analysis revealed approximately 3000 genes that were altered across all treatment groups (±1.3 fold; p<0.1). Several inflammatory mediators changed in a dose- and time-dependent manner at both the mRNA and protein level. Although no influx of neutrophils was detected at the low dose, changes in the expression of several genes and proteins associated with inflammation were observed. Resolving inflammation at the medium dose, and lack of neutrophil influx in the lung fluid at the low dose, were associated with down-regulation of genes involved in ion homeostasis and muscle regulation. Our gene expression results imply that retention of nano-TiO2 in the absence of inflammation over time may potentially perturb calcium and ion homeostasis, and affect smooth muscle activities