More data on in vitro assessment of comparative and combined toxicity of metal oxide nanoparticles

On the Mechanisms of the Cardiotoxic Effect of Lead Oxide Nanoparticles

Lead compounds are one of the most common pollutants of the workplace air and the environment. In the occupational setting, the sources of their emission, including in nanoscale form, are various technological processes associated with lead smelting and handling of non-ferrous metals and their alloys, the production of copper and batteries. Both lead poisoning and lead exposure without obvious signs of poisoning have a detrimental effect on the cardiovascular system. The purpose of this research was to investigate the mechanisms of the cardiotoxic effect of lead oxide nanoparticles (PbO NPs). The toxicological experiment involved male albino rats subchronically exposed to PbO NPs (49.6 ± 16.0 nm in size) instilled intraperitoneally in a suspension. We then assessed post-exposure hematological and biochemical parameters of blood and urine, histological and ultrastructural changes in cardiomyocytes, and non-invasively recorded electrocardiograms and blood pressure parameters in the rodents. Myocardial contractility was studied on isolated preparations of cardiac muscles. We established that PbO NPs induced oxidative stress and damage to the ultrastructure of cardiomyocytes, and decreased efficiency of the contractile function of the myocardium and blood pressure parameters. We also revealed such specific changes in the organism of the exposed rats as anemia, hypoxia, and hypocalcemia.

Dose Dependence of the Separate and Combined Impact of Copper-Oxide and Selenium-Oxide Nanoparticles on Oxygen Consumption by Cells In Vitro With or Without the Background Action of Some Modulators of the Mitochondrial Respiratory Function

We had previously demonstrated on various stable cell cultures exposed to chemically different nanoparticles when assessing their cytotoxicity by different outcomes, dose-response relationships may be either monotonic or non-monotonic falling within an extended understanding of the hormesis paradigm. Presently, on human fibroblasts exposed to the copper-oxide and/or selenium-oxide nanoparticles, we assessed their cytotoxic effect by the inhibition of oxygen uptake against modulating the respiratory function of mitochondria (oligomycin, followed by carbonyl cyanide-4-(trifluoromethoxy) phenylhydrazone, and, finally, rotenone with antimycin A). It is hypothesized that a given type of this relationship is closely associated with the mitochondrial respiratory function. However, in only one case, this hypothesis was confirmed by finding that the monotonic dose-response relationship transformed into a non-monotonic one of the hormesis type under exposure to SeO-NP with the mitochondrial respiratory function fully inhibited by the effect of rotenone + antimycin А. In all other variants of the experiment, the shape of this relationship did not depend on the addition of the above agents to the cell culture. Neither did the effect of these modulators change the pattern of combined action of CuO-NP and SeO-NP, which was additive in all cases.

Synthesis, biomedical applications, and toxicity of CuO nanoparticles

Versatile nature of copper oxide nanoparticles (CuO NPs) has made them an imperative nanomaterial being employed in nanomedicine. Various physical, chemical, and biological methodologies are in use for the preparation of CuO NPs. The physicochemical and biological properties of CuO NPs are primarily affected by their method of fabrication; therefore, selectivity of a synthetic technique is immensely important that makes these NPs appropriate for a specific biomedical application. The deliberate use of CuO NPs in biomedicine questions their biocompatible nature. For this reason, the present review has been designed to focus on the approaches employed for the synthesis of CuO NPs; their biomedical applications highlighting antimicrobial, anticancer, and antioxidant studies; and most importantly, the in vitro and in vivo toxicity associated with these NPs. This comprehensive overview of CuO NPs is unique and novel as it emphasizes on biomedical applications of CuO NPs along with its toxicological assessments which would be useful in providing core knowledge to researchers working in these domains for planning and conducting futuristic studies. KEY POINTS: • The recent methods for fabrication of CuO nanoparticles have been discussed with emphasis on green synthesis methods for different biomedical approaches. • Antibacterial, antioxidant, anticancer, antiparasitic, antidiabetic, and antiviral properties of CuO nanoparticles have been explained. • In vitro and in vivo toxicological studies of CuO nanoparticles exploited along with their respective mechanisms.

Comparative and Combined In Vitro Vasotoxicity of Nanoparticles Containing Lead and Cadmium

In vitro toxicological experiments were performed on an endothelial cell line exposed to different doses of spherical nanoparticles of cadmium and/or of lead sulfides with mean diameter 37 ± 5 nm and 24 ± 4 nm, respectively. Toxic effects were estimated by Luminescent Cell Viability Assay, endothelin-1 concentration and cell size determination. Some dose-response relationships were typically monotonic (well approximated with hyperbolic function) while others were bi- or even 3-phasic and could be described within the expanded hormesis paradigm. The combined toxicity type variated depending on the effect it was assessed by.

Mechanical and optical behaviors: strain synergy effects in high temperature phase oxides of lead

The structural, electronic, mechanical and optical properties of lead oxide (α-PbO, β-PbO, CsCl–PbO, α-PbO2, and β-PbO2) systems were studied. Furthermore, these results may motivate more experimental and theoretical studies on different phases of lead oxides under high pressure and temperature.

Some data on the comparative and combined toxic activity of nanoparticles containing lead and cadmium with special attention to their vasotoxicity

Moderate subchronic intoxication was induced in rats by repeated intraperitoneal injections of PbO (49.6 ± 16.0 nm) and/or CdO (57.0 ± 13.0 nm) nanoparticles (NP) three times a week during 6 weeks. In particular, there was a reduction in arterial blood pressure and in blood concentrations of a number of factors controlling vasoconstriction and vasodilation, particularly of endothelin 1 (ET-1). This toxic effect was attenuated with a bioprotective complex administered in the background. The study confirmed as well that the combined binary action typology varies depending on which effect it is estimated by.

An overview of experiments with lead-containing nanoparticles performed by the Ekaterinburg nanotoxicological research team

Over the past few years, the Ekaterinburg (Russia) interdisciplinary nanotoxicological research team has carried out a series of investigations using different in vivo and in vitro experimental models in order to elucidate the cytotoxicity and organ-systemic and organism-level toxicity of lead-containing nanoparticles (NP) acting separately or in combinations with some other metallic NPs. The authors claim that their many-sided experience in this field is unique and that some of their important results have been obtained for the first time. This paper is an overview of the team's previous publications in different journals. It is suggested to be used as a compact scientific base for assessing health risks associated not only with the production and usage of engineered lead-containing NPs but also with their inevitable by-production as toxic air pollutants in the metallurgy of lead, copper or their alloys and in soldering operations.

Variability in the Clearance of Lead Oxide Nanoparticles Is Associated with Alteration of Specific Membrane Transporters

Lead oxide nanoparticles (PbONPs), upon their entry into the lungs via inhalation, induce structural changes in primary and secondary target organs. The fate and ultrastructural localization of PbONPs in organs is known to be dependent on the specific organ. Here, we focused on the differences in the ability to clear the inhaled PbONPs from secondary target organs and on molecular and cellular mechanisms contributing to nanoparticle removal. Mice were exposed to PbONPs in whole-body inhalation chambers. Clearance of ionic lead and PbONPs (Pb/PbONPs) from the lungs and liver was very effective, with the lead being almost completely eliminated from the lungs and the physiological state of the lung tissue conspicuously restored. Kidneys exposed to nanoparticles did not exhibit serious signs of damage; however, LA-ICP-MS uncovered a certain amount of lead located preferentially in the kidney cortex even after a clearance period. The concentration of lead in femurs, as representatives of the axial skeleton, was the highest among studied organs at all designated time points after PbONP exposure, and the clearance ability of lead from the femurs was very low in contrast to other organs. The organ-specific increase of ABC transporters expression (ABCG2 in lungs and ABCC3 in the liver) was observed in exposed animals, suggesting their involvement in removing Pb/PbONPs from tissues. Moreover, the expression of caveolins and clathrin displayed a tissue-specific response to lead exposure. Our results uncovered high variability among the organs in their ability to clear Pb/PbONPs and in the transporters involved in this process.

Some Peculiarities in the Dose Dependence of Separate and Combined In Vitro Cardiotoxicity Effects Induced by CdS and PbS Nanoparticles With Special Attention to Hormesis Manifestations

Spherical nanoparticles (NPs) of cadmium and lead sulfides (diameter 37 ± 5 and 24 ± 4 nm, respectively) have been found to be cytotoxic for HL-1 cardiomyocytes as evidenced by decrease in adenosine triphosphate-dependent luminescence. Cadmium sulfide (CdS)-NPs were discovered to produce a much greater cytotoxic impact than lead sulphide (PbS)-NP. Given the same dose range, CdS-NP reduced the number of calcium spikes. A similar effect was observed for small doses of PbS-NP. In addition to cell hypertrophy under the impact of certain doses of CdS-NP and PbS-NP, doses causing cardiomyocyte size reduction were identified. For these 3 outcomes, we obtained both monotonic "dose-response" functions (well approximated by the hyperbolic function) and different variants of non-monotonic ones for which we found adequate mathematical expressions by modifying certain models of hormesis available in the literature. Data analysis using a response surface linear model with a cross-term provided new support to the previously established postulate that a diversity of types of joint action characteristic of one and the same pair of damaging agents is one of the important assertions of the general theory of combined toxicity.

The Effect of Silver Nanoparticles on Antioxidant/Pro-Oxidant Balance in a Murine Model

This study aimed to evaluate the subacute effect of two types of Ag-NPs(EG-AgNPs and PVP-EG-AgNPs) on antioxidant/pro-oxidant balance in rats. Seventy Wistar rats (35 males and 35 females) were divided in 7 groups and intraperitoneally exposed for 28 days to 0, 1, 2 and 4 mg/kg bw/day EG-Ag-NPs and 1, 2 and 4 mg/kg bw/day PVP- EG-Ag-NPs. After 28 days, the blood was collected, and the total antioxidant capacity (TAC), thiobarbituric reactive species (TBARS),protein carbonyl (PROTC) levels, reduced glutathione (GSH) levels and catalase (CAT) activity were determined. EG-Ag-NPs determined protective antioxidant effects in a dose-dependent manner. The exposure to the 4 mg/kg bw/day EG-Ag-NPs determines both in males and females a significant increase in TAC and CAT and a significant decrease in TBARS and PROTC only in females. The PVP-EG-AgNPs showed a different trend compared to EG-AgNPs. At 4 mg/kg bw/day the PVP-EG-AgNPs induce increased PROTC levels and decreased GSH (males and females) and TAC levels (males). The different mechanisms of EG-AgNPs and PVP-EG-AgNPs on antioxidant-/pro-oxidant balance can be explained by the influence of coating agent used for the preparation of the nanoparticles in the formation and composition of protein corona that influence their pathophysiology in the organism.

Manifestation of Systemic Toxicity in Rats after a Short-Time Inhalation of Lead Oxide Nanoparticles

Outbred female rats were exposed to inhalation of lead oxide nanoparticle aerosol produced right then and there at a concentration of 1.30 ± 0.10 mg/m³ during 5 days for 4 h a day in a nose-only setup. A control group of rats were sham-exposed in parallel under similar conditions. Even this short-time exposure of a relatively low level was associated with nanoparticles retention demonstrable by transmission electron microscopy in the lungs and the olfactory brain. Some impairments were found in the organism’s status in the exposed group, some of which might be considered lead-specific toxicological outcomes (in particular, increase in reticulocytes proportion, in δ-aminolevulinic acid (δ-ALA) urine excretion, and the arterial hypertension’s development).