Metal-Based Nanoparticles and Their Relevant Consequences on Cytotoxicity Cascade and Induced Oxidative Stress

Tellurium and Nano-Tellurium: Medicine or Poison?

Tellurium (Te) is the heaviest stable chalcogen and is a rare element in Earth's crust (one to five ppb). It was discovered in gold ore from mines in Kleinschlatten near the present-day city of Zlatna, Romania. Industrial and other applications of Te focus on its inorganic forms. Tellurium can be toxic to animals and humans at low doses. Chronic tellurium poisoning endangers the kidney, liver, and nervous system. However, Te can be effective against bacteria and is able to destroy cancer cells. Tellurium can also be used to develop redox modulators and enzyme inhibitors. Soluble salts that contain Te had a role as therapeutic and antimicrobial agents before the advent of antibiotics. The pharmaceutical use of Te is not widespread due to the narrow margin between beneficial and toxic doses, but there are differences between the measure of toxicity based on the Te form. Nano-tellurium (Te-NPs) has several applications: it can act as an adsorptive agent to remove pollutants, and it can be used in antibacterial coating, photo-catalysis for the degradation of dyes, and conductive electronic materials. Nano-sized Te particles are the most promising and can be produced in both chemical and biological ways. Safety assessments are essential to determine the potential risks and benefits of using Te compounds in various applications. Future challenges and directions in developing nano-materials, nano-alloys, and nano-structures based on Te are still open to debate.

Effects of iron oxide nanoparticles on the gene expression profiles of cerebral endotheliocytes and astrocytes

Iron oxide nanoparticles (IONPs) are considered as the most biocompatible magnetic materials suitable for biomedical applications. Nevertheless, there are many evidences of their toxicity for living organisms and partially neurotoxicity. The central nervous system is protected from undesirable substances circulating in the bloodstream by the blood-brain barrier (BBB). And even if being small enough, some nanoparticles could be able to penetrate cell membranes in other cells but will often be delayed by the BBB cells. However, the neurotoxicity of iron oxide is described even in the cases when IONPs should not uptake to the nervous system by experimental design. The aim of this study was to investigate what molecular changes in the cells-components of BBB - endotheliocytes and underlying astrocytes - may be caused by IONPs in the blood vessels of the brain. For this, a two-layer in vitro BBB model was created, consisting of rat cerebral endothelial cells and astrocytes. It was revealed that 100 and 200 mg/L of the nanoparticles induce metabolism alteration in the cells under study. Using RNA-sequencing, the up-regulation of pro-inflammatory chemokines encoding genes and changes in the expression of genes associated with detoxification in the endotheliocytes were demonstrated under the influence of 100 mg/L IONPs.

The distribution, fate, and environmental impacts of food additive nanomaterials in soil and aquatic ecosystems

Nanomaterials in the food industry are used as food additives, and the main function of these food additives is to improve food qualities including texture, flavor, color, consistency, preservation, and nutrient bioavailability. This review aims to provide an overview of the distribution, fate, and environmental and health impacts of food additive nanomaterials in soil and aquatic ecosystems. Some of the major nanomaterials in food additives include titanium dioxide, silver, gold, silicon dioxide, iron oxide, and zinc oxide. Ingestion of food products containing food additive nanomaterials via dietary intake is considered to be one of the major pathways of human exposure to nanomaterials. Food additive nanomaterials reach the terrestrial and aquatic environments directly through the disposal of food wastes in landfills and the application of food waste-derived soil amendments. A significant amount of ingested food additive nanomaterials (> 90 %) is excreted, and these nanomaterials are not efficiently removed in the wastewater system, thereby reaching the environment indirectly through the disposal of recycled water and sewage sludge in agricultural land. Food additive nanomaterials undergo various transformation and reaction processes, such as adsorption, aggregation-sedimentation, desorption, degradation, dissolution, and bio-mediated reactions in the environment. These processes significantly impact the transport and bioavailability of nanomaterials as well as their behaviour and fate in the environment. These nanomaterials are toxic to soil and aquatic organisms, and reach the food chain through plant uptake and animal transfer. The environmental and health risks of food additive nanomaterials can be overcome by eliminating their emission through recycled water and sewage sludge.

Radiofrequency driving antitumor effect of graphene oxide-based nanocomposites: a Hill model analysis

Aim: This report proposes using the Hill model to assess the benchmark dose, the 50% lethal dose, the cooperativity and the dissociation constant while analyzing cell viability data using nanomaterials to evaluate the antitumor potential while combined with radiofrequency therapy. Materials & methods: A nanocomposite was synthesized (graphene oxide-polyethyleneimine-gold) and the viability was evaluated using two tumor cell lines, namely LLC-WRC-256 and B16-F10. Results: Our findings demonstrated that while the nanocomposite is biocompatible against the LLC-WRC-256 and B16-F10 cancer cell lines in the absence of radiofrequency, the application of radiofrequency enhances the cell toxicity by orders of magnitude. Conclusion: This result points to prospective studies with the tested cell lines using tumor animal models.

Iron oxide nanoparticles induced cytotoxicity, oxidative stress, cell cycle arrest, and DNA damage in human umbilical vein endothelial cells

BACKGROUND

Nanotechnology and material science have developed enormously fast in recent years. Due to their excellent magnetic properties, iron oxide nanoparticles (IONPs) have been broadly applied in the field of bioengineering and biomedical. Thus, it is important to evaluate the safety issues and health effects of these nanomaterials. The present investigation was aimed to evaluate the adverse effects of IONPs on human umbilical vein endothelial cells (HUVECs).

METHODS

The cytotoxic potential of IONPs was assessed by MTT and neutral red uptake (NRU) assays. The impact of IONPs on oxidative stress markers (glutathione (GSH) and lipid peroxidation (LPO)), reactive oxygen species (ROS) production, and mitochondrial membrane potential (MMP) was also examined. Furthermore, the toxic effect of IONPs was quantified by assessing DNA damage, cell cycle arrest, and apoptosis by quantitative real time PCR.

RESULTS

We found that IONPs induce a dose-dependent cytotoxicity on HUVECs with IC50 value of 79.13 μg/mL. The results also displayed that IONPs induce oxidative stress, ROS production, and mitochondrial membrane dysfunction. The comet assay results exhibited IONPs induces DNA damage in HUVECs. We found significant cell cycle arrest at SubG1 phase in treated cells and consequent cell death was evidenced by microscopic analysis. Moreover, IONPs display substantial up-regulation of pro-apoptotic genes and down-regulation of anti-apoptotic gene evidenced by real time qPCR.

CONCLUSION

Overall, our results clearly demonstrated that IONPs have the potential to induce cytotoxicity, DNA damage, cell cycle arrest, and apoptosis in HUVECs mediated through oxidative stress and ROS production. Thus, IONPs are cytotoxic and it should be handled with proper care.

Esawy AELW. Evaluating the hepatotoxic versus the nephrotoxic role of iron oxide nanoparticles: One step forward into the dose-dependent oxidative effects

The present study has been designed to detect the dose-dependent effect of iron oxide nanoparticles (IONPs) on the liver and kidney of rats by evaluating three different doses 30, 300, 1000 mg/kg/day IONPs for 28 days. Forty rats were divided into four groups; I (control), II (low dose), III (medium dose) and IV (high dose). There also was a statistically-significant elevation in the serum levels of hepatic enzymes; AST and ALT in medium & high dose. The elevation of serum ALP, on the other hand, was significant in all IONPs doses. There was significant elevation in the levels of urea creatinine, and MDA in the medium and high doses of IONPs. The activity of superoxide dismutase (SOD) and glutathione peroxidase (GPx) showed significant decrease in the high dose only compared to the control group. The serum iron levels increased in a dose-dependent manner in the IONPs-treated groups with highly significant increase in the moderate and high dose groups. On comparing the effect of different doses of IONPs between the liver and kidney, the high dose revealed statistically significant difference (p < 0.05) in the area percent of collagen deposition (54.4 ± 3.9 versus 6.1 ± 2.6) and alpha smooth muscle actin (α-SMA) reaction (7.7 ± 1.5 versus 17.8 ± 4.3) in the liver relative to the kidney. The medium and high doses revealed statistically significant difference in optical density of Periodic acid Schiff (PAS) reaction (45 ± 3.4 versus 50.3 ± 1.8 in the medium dose, and 38.9 ± 6 versus 63 ± 3 in the high dose) and area percent of inducible nitric oxide synthase (iNOS) reaction (12.98 ± 2.7 versus 3.5 ± 0.5 in the medium dose, and 27.91 ± 1.5 versus 7.7 ± 0.6 in the high dose) in the liver relative to the kidney.