Papers by Keyword: Nanotoxicology

Abstract: For the first time studied the influence of nickel nanoparticles (Ni NPs) on the integrated index of biological activity of humus soil horizons in subboreal forest after treating with a 5.0 mg/l dispersion of nanoparticles. Adding nickel nanoparticle dispersion into the soil was carried out in filtration columns. Treatment of humus soils with Ni NPs has been established to decrease total microbial number to 50 % - 65 % in CFU, stimulate nitrification in all soil samples and a suppression of nitrogen fixation in loam soils Model tests on agar media with pure cultures of Pseudomonas fluorescens and Candida sp. showed varied sensitivity of different systematic groups to nickel nanoparticles. No positive CFU decrease of Pseudomonas fluorescens was found. However, in respect to certain concentrations of Ni NPs in an experiment with Candida sp., a marked decrease of CFU was observed.

Abstract: The marine bivalves, mussels Crenomytilus grayanus (Dunker, 1853) and scallops Swiftopecten swifti (Bernardi, 1858), were in vivo exposed to 12-14 nm multi-walled carbon nanotubes (MWNTs) for up to 48 h. Microscopic analysis in combination with the RAMAN spectrophotometry revealed the MWNT aggregates on the gills surface and inside the gut of all exposed individuals. After 48 h exposure, there were no changes in the total cell count, the average cell size and granularity in the hemolymph of mussels, while in the scallops the total hemocyte count was significantly reduced, and the average hemocyte granularity increased. Biochemical markers of oxidative stress (activity of glutathione-S-transferase and catalase, concentration of reduced glutathione, and the degree of lipid peroxidation) did not change significantly in the digestive gland of both mussels and scallops. In hemolymph, catalase activity increased as compared to control in both mussels and scallops. Moreover, concentration of reduced glutathione increased in hemolymph of scallops on the second day of exposure to MWNTs. The data obtained indicate that MWNTs may affect different bivalve mollusks more or less strongly under the same exposure conditions.

Abstract: The exponential growth of nanoparticle-containing goods and waste of the recent years will lead unavoidably to nanomaterials entering environment, generating in local biota and abiotic environment, and potentially transmitting to man. Aerial and water transmission of nanoparticles eventually will cause its generation in soil and further transmission to plants and animals via food chains.

Abstract: Copper oxide nanoparticles (CuO NPs) are used in antimicrobial preparations, heat transfer fluids, semi-conductors or intrauterine contraceptive devices. Nanoparticles with unique magnetic, luminescent, and catalytic properties are being engineered for numerous biomedical applications, including imaging, diagnostics and therapy. However, potentially harmful interactions can occur between nanoparticles and living systems, including humans. The present study was aimed to assess the cytotoxicity of CuO NPs in human alveolar epithelial cell line (A549). A reduction in cell viability as a function of NP concentration for 24h was observed. CuO NPs were also found to induce oxidative stress in cells indicated by generation of H₂O₂. Our data demonstrates that CuO NPs even at low concentrations lead to cell membrane damage in human epidermal cells which may be mediated through lipid peroxidation and oxidative stress, however, induced little effect to Mitochondria. Hence, caution should be taken in their widely use as well as while handling.

Abstract: Nanoparticles may invade directly into the internal body through the respiratory or digestive system and diffuse inside body. The behavior of nanoparticles in the internal body is also essential to comprehend for the realization of DDS. Thus it is necessary to reveal the internal dynamics for the proper treatments and biomedical applications of nanoparticles. In the present study the plural methods with different principles such as X-ray scanning analytical microscope (XSAM), MRI and Fluorescent microscopy were applied to enable the observation of the internal diffusion of micro/nanoparticles in the (1) whole body level, (2) inner organ level and (3) tissue and intracellular level. Chemical analysis was also done by ICP-AES for organs and compared with the results of XSAM mapping.

Abstract: Both biochemical cell functional test and animal implantation test were done to investigate the reaction to fine particles. Particles cause nonspecifically phagocytosis to cells and inflammation to tissue for the size below 10m. With the size below 50nm particles may invade into the internal body through the respiratory or digestive system and diffuse inside body. Ti mapping by XSAM after the compulsory exposure test to the respiratory system showed the internal diffusion of 30nm TiO2 particles. They diffused with time course to lung, liver and spleen after injection from caudal vein. Nanoparticles might be the objects whose existence has not been assumed by the biophylactic system.