Lack of cytotoxic and genotoxic effects of mPEG-silane coated iron(III) oxide nanoparticles doped with magnesium despite cellular uptake in cancerous and noncancerous lung cells.

Cytotoxic and genotoxic effects of novel mPEG-silane coated iron(III) oxide nanoparticles doped with magnesium (Mg-γ-FeO(mPEG-silane)) have been investigated on human adenocarcinomic alveolar basal epithelial (A549) and human normal bronchial epithelial (BEAS-2B) cells. In the studies several molecular and cellular targets addressing to cell membrane, cytoplasm organelles and nucleus components were served as toxicological endpoints. The as-synthesized nanoparticles were found to be stable in the cell culture media and were examined for different concentration and exposure times.

Long-term cryopreservation of potassium bromate positive assay controls for measurement of oxidatively damaged DNA by the Fpg-modified comet assay: results from the hCOMET ring trial.

The formamidopyrimidine DNA glycosylase (Fpg)-modified comet assay is widely used for the measurement of oxidatively generated damage to DNA. However, there has not been a recommended long-term positive control for this version of the comet assay. We have investigated potassium bromate as a positive control for the Fpg-modified comet assay because it generates many Fpg-sensitive sites with a little concurrent generation of DNA strand breaks.

DNA strand break levels in cryopreserved mononuclear blood cell lines measured by the alkaline comet assay: results from the hCOMET ring trial.

The comet assay is widely used in biomonitoring studies for the analysis of DNA damage in leukocytes and peripheral blood mononuclear cells. Rather than processing blood samples directly, it can be desirable to cryopreserve whole blood or isolated cells for later analysis by the comet assay. However, this creates concern about artificial accumulation of DNA damage during cryopreservation.

Visual comet scoring revisited: a guide to scoring comet assay slides and obtaining reliable results.

Measurement of DNA migration in the comet assay can be done by image analysis or visual scoring. The latter accounts for 20%-25% of the published comet assay results. Here we assess the intra- and inter-investigator variability in visual scoring of comets.

Inter-laboratory variation in measurement of DNA damage by the alkaline comet assay in the hCOMET ring trial.

The comet assay is a simple and versatile method for measurement of DNA damage in eukaryotic cells. More specifically, the assay detects DNA migration from agarose gel-embedded nucleoids, which depends on assay conditions and the level of DNA damage. Certain steps in the comet assay procedure have substantial impact on the magnitude of DNA migration (e.

RENEB Inter-Laboratory Comparison 2021: The Gamma-H2AX Foci Assay.

The Running the European Network of biological and retrospective dosimetry (RENEB) network of laboratories has a range of biological and physical dosimetry assays that can be deployed in the event of a radiation incident to provide exposure assessment. To maintain operational capability and provide training, RENEB runs regular inter-laboratory comparison (ILC) exercises. The RENEB ILC2021 was carried out with all the biological and physical dosimetry assays employed in the network.

Preclinical Evaluation of 225Ac-Labeled Single-Domain Antibody for the Treatment of HER2pos Cancer.

Human epidermal growth factor receptor type 2 (HER2) is overexpressed in various cancers; thus, HER2-targeting single-domain antibodies (sdAb) could offer a useful platform for radioimmunotherapy. In this study, we optimized the labeling of an anti-HER2-sdAb with the α-particle-emitter 225Ac through a DOTA-derivative. The formed radioconjugate was tested for binding affinity, specificity and internalization properties, whereas cytotoxicity was evaluated by clonogenic and DNA double-strand-breaks assays.

Silver Nanoparticles Inhibit Metastasis of 4T1 Tumor in Mice after Intragastric but Not Intravenous Administration.

The potential anticancer activity of different silver nanoformulations is increasingly recognized. In the present work, we use the model of 4T1 tumor in BALB/ccmdb immunocompetent mice to analyze the impact of citrate- and PEG-coated silver nanoparticles (AgNPs) on the development and metastatic potential of breast cancer. One group of mice was intragastrically administered with 1 mg/kg body weight (b.

Increased DNA repair capacity augments resistance of glioblastoma cells to photodynamic therapy.

Photodynamic therapy (PDT) is a clinically approved cancer therapy of low invasiveness. The therapeutic procedure involves administering a photosensitizing drug (PS), which is then activated with monochromatic light of a specific wavelength. The photochemical reaction produces highly toxic oxygen species.

Susceptibility of HepG2 Cells to Silver Nanoparticles in Combination with other Metal/Metal Oxide Nanoparticles.

The fast-growing use of nanomaterials in everyday life raises the question about the safety of their use. Unfortunately, the risks associated with the use of nanoparticles (NPs) have not yet been fully assessed. The majority of studies conducted so far at the molecular and cellular level have focused on a single-type exposure, assuming that NPs act as the only factor.

Potassium bromate as positive assay control for the Fpg-modified comet assay.

The comet assay is a popular assay in biomonitoring studies. DNA strand breaks (or unspecific DNA lesions) are measured using the standard comet assay. Oxidative stress-generated DNA lesions can be measured by employing DNA repair enzymes to recognise oxidatively damaged DNA.

Biological effects of mixed-ion beams. Part 2: The relative biological effectiveness of CHO-K1 cells irradiated by mixed- and single-ion beams.

The relative biological effectiveness (RBE) values were determined for single- and mixed-ion beams containing carbon and oxygen ions. The CHO-K1 cells were irradiated with beams with the linear energy transfer (LET) values of 236-300 and 461-470 keV/μm for C and O ions, respectively. The RBE was estimated as a function of dose, survival fraction (SF) and LET.

Biological effects of mixed-ion beams. Part 1: Effect of irradiation of the CHO-K1 cells with a mixed-ion beam containing the carbon and oxygen ions.

Carbon and oxygen ions were accelerated simultaneously to estimate the effect of irradiation of living cells with the two different ions. This mixed ion beam was used to irradiate the CHO-K1 cells, and a survival test was performed. The type of the effect of the mixed ion beam on the cells was determined with the isobologram method, whereby survival curves for irradiations with individual ion beams were also used.

Crucial role of chelatable iron in silver nanoparticles induced DNA damage and cytotoxicity.

Damage to mitochondria and subsequent ROS leakage is a commonly accepted mechanism of nanoparticle toxicity. However, malfunction of mitochondria results in generation of superoxide anion radical (O-), which due to the relatively low chemical reactivity is rather unlikely to cause harmful effects triggered by nanoparticles. We show that treatment of HepG2 cells with silver nanoparticles (AgNPs) resulted in generation of HO instead of O-, as measured by ROS specific mitochondrial probes.

Genotoxic potential of diesel exhaust particles from the combustion of first- and second-generation biodiesel fuels-the FuelHealth project.

Epidemiological data indicate that exposure to diesel exhaust particles (DEPs) from traffic emissions is associated with higher risk of morbidity and mortality related to cardiovascular and pulmonary diseases, accelerated progression of atherosclerotic plaques, and possible lung cancer. While the impact of DEPs from combustion of fossil diesel fuel on human health has been extensively studied, current knowledge of DEPs from combustion of biofuels provides limited and inconsistent information about its mutagenicity and genotoxicity, as well as possible adverse health risks. The objective of the present work was to compare the genotoxicity of DEPs from combustion of two first-generation fuels, 7% fatty acid methyl esters (FAME) (B7) and 20% FAME (B20), and a second-generation 20% FAME/hydrotreated vegetable oil (SHB: synthetic hydrocarbon biofuel) fuel.

The second gamma-H2AX assay inter-comparison exercise carried out in the framework of the European biodosimetry network (RENEB).

Purpose: Within the EU RENEB project, seven laboratories have taken part in training and harmonisation activities to strengthen triage gamma-H2AX-based radiation exposure assessment. This has culminated in a second triage biodosimetry exercise.

Materials And Methods: Whole blood and separated lymphocyte samples were homogenously irradiated with Co gamma rays at 0.

Silver and titanium dioxide nanoparticles alter oxidative/inflammatory response and renin-angiotensin system in brain.

The study was designed to examine the effects of silver AgNPs, 20 nm) and titanium dioxide (Aeroxide(®) P25 TiO2NPs, 21 nm) nanoparticles on brain oxidative stress parameters, its antioxidant potential and brain renin-angiotensin system (RAS) in vivo. The analysis was performed 28 days after single dose injection of TiO2NPs and AgNPs (10 or 5 mg/kg body weight, respectively). The AgNPs, but not TiO2NPs, administration resulted in decreased lipid and cholesterol peroxidation.

Defining Blood Processing Parameters for Optimal Detection of γ-H2AX Foci: A Small Blood Volume Method.

Biodosimetric methods used to measure the effects of radiation are critical for estimating the health risks to irradiated individuals or populations. The direct measurement of radiation-induced γ-H2AX foci in peripheral blood lymphocytes is one approach that provides a useful end point for triage. Despite the documented advantages of the γ-H2AX assay, there is considerable variation among laboratories regarding foci formation in the same exposure conditions and cell lines.

Investigation of the bystander effect in CHO-K1 cells.

Aim: Investigation of the bystander effect in Chinese Hamster Ovary cells (CHO-K1) co-cultured with cells irradiated in the dose range of 0.1-4 Gy of high LET C ions and X-rays.

Background: The radiobiological effects of charged heavy particles on a cellular or molecular level are of fundamental importance in the field of biomedical applications, especially in hadron therapy and space radiation biology.

Oxidative DNA damage corresponds to the long term survival of human cells treated with silver nanoparticles.

We examined the relation between DNA damage and the clonogenic potential of 3 human cell lines, HepG2, HT29 and A549, treated with bare 20 nm or 200 nm silver nanoparticles (AgNPs). The endpoints examined were the DNA breakage estimated by the comet assay, the oxidative base damage recognized by formamido-pyrimidine glycosylase (FPG) and estimated with the FPG+comet assay, and the frequencies of histone γH2AX foci and micronuclei. Each cell line studied had a different pattern of DNA breakage and base damage versus the NPs concentration and time of treatment.

The dose-response relationship for dicentric chromosomes and γ-H2AX foci in human peripheral blood lymphocytes: influence of temperature during exposure and intra- and inter-individual variability of donors.

Purpose: Hypothermia during in vitro irradiation of human peripheral blood lymphocytes (PBL) affects the level of chromosome aberrations. The molecular mechanisms of this phenomenon are not fully understood. The aim of our study was to examine the effect of hypothermia on the dose-response relationship for dicentric chromosomes and the level of γ-H2AX (phosphorylated histone H2AX) foci.

Cis-9,trans-11-conjugated linoleic acid affects lipid raft composition and sensitizes human colorectal adenocarcinoma HT-29 cells to X-radiation.

Background: Investigations concerned the mechanism of HT-29 cells radiosensitization by cis-9,trans-11-conjugated linoleic acid (c9,t11-CLA), a natural component of human diet with proven antitumor activity.

Methods: The cells were incubated for 24h with 70μM c9,t11-CLA and then X-irradiated. The following methods were used: gas chromatography (incorporation of the CLA isomer), flow cytometry (cell cycle), cloning (survival), Western blotting (protein distribution in membrane fractions), and pulse-field gel electrophoresis (rejoining of DNA double-strand breaks).

Silver nanoparticles effects on epididymal sperm in rats.

The motivation of our study was to examine the acute effects of intravenously administered a single bolus dose of silver nanoparticles (AgNPs) on rat spermatogenesis and seminiferous tubules morphology. In the treated rats compared to the vehicle treated control animals, the experiments revealed a size-dependent (20nm and 200nm), dose-dependent (5 and 10mg/kg body mass) and time-dependent (24h, 7 and 28days) decrease the epididymal sperm count measured by histological methods. In parallel AgNPs injection increased the level of DNA damage in germ cells, as measured by alkaline comet assay.

Ag nanoparticles: size- and surface-dependent effects on model aquatic organisms and uptake evaluation with NanoSIMS.

This study aims to assess the effects of Ag particles synthesised by a chemical (Ag 20, 200 nm) and biological method (Ag 23, 27 nm) in aquatic organisms: the bacterium Vibrio fischeri, the alga Desmodesmus subspicatus and the crustacean Daphnia magna. Ag particles exerted toxic effects in all organisms studied with Ag particles 23 nm being the most potent. Although soluble Ag was released in all media, the differences between the tested Ag particles still cannot be explained solely based on soluble Ag.