Risk assessment of arsenic intake from food and water in the SR

For human, arsenic (As) is toxic substance which is widely transported from natural and anthropogenic resources into environmental components with consequent risk of transport into food and potable water. Oral intake is the most significant source of exposure. Toxicity of As is different depending on the form. Risk assessment of human exposure to As results from available databases of food and potable water analyses, which quote only the concentrations of total As. Mean As concentrations in food and potable water in the SR are below the appropriate limits. The maximum limit was exceeded only in maximum levels of edible fats and oils. Comparing As concentrations in individual commodities between the localities in the SR, the highest contents were found in Kosice region. Evaluation of non-carcinogenic risk from oral exposure to As in general population considering the mean exposure scenario did not show risk, because the hazard index was below or only minimally above the value 1. The risk was only found when using the maximal lifelong exposure scenario, which is not probable. Risk assessment of infant exposure to As from human milk showed the hazard index below 1 also for maximal exposure scenario. Carcinogenic risk for present intake of food and potable water was 5.7x10-4 for adult population and 2.8x10-4 for infants, considering the mean exposure scenario. Using the non-probable maximal exposure scenario, the value of carcinogenic risk for exposure to inorganic As from food and water was 1.7x10-2 for adult population. For infants, this value was 4.5x10-4 considering the maximal exposure to inorganic As from human milk. The results of total As concentrations in food and potable water in the SR indicate that Slovakia belongs to countries with the lowest mean oral intake of arsenic within Europe. Despite this fact, it is necessary to continue in monitoring of As in environmental components and biological materials with specialisation in determination of inorganic As

Effect of magnetic nanoparticles coating on cell proliferation and uptake

Magnetic iron oxide nanoparticles (MNPs) are one of the most promising types of nanoparticles for biomedical applications, primarily in the context of nanomedicine-based diagnostics and therapy. They are used as contrast agents in magnetic resonance imaging and magnetite cell labelling. Furthermore, they are promising heating mediator in magnetic hyperthermia-based therapy, and can serve as nanocarriers in targeted gene and drug delivery as well. In biomedical applications, coating plays an important role in nanoparticle dispersion stability and biocompatibility. However, the impact of nanoparticle surface chemistry on cell uptake and proliferation has not been sufficiently investigated. The objective of this study is to prepare magnetic nanoparticles with inner magnetite core and hydrophilic outer shell of surfactant, protein and polymers that are commonly used in biomedical research. MNPs were characterized in-depth by various physicochemical methods. Magnetic hyperthermia, applied to find out the influence of MNPs coating on heating characteristics of the samples, did not show any correlation between layer thickness and specific adsorption rate. To evaluate the impact of surface chemistry on cell proliferation and internalization, the human lung adenocarcinoma epithelial (A549) cells were utilized. Substantial differences were determined in the amount of internalized MNPs and cell viability in dependence on surface coating. Our results indicate that the surface chemistry not only protects particles from agglomeration but also affect the interaction between cell and MNPs. © 2018 Elsevier B.V