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The role of dispersion medium on nanoparticle aggregation and size in biological systems
Červená, Tereza ; Rössnerová, Andrea ; Závodná, Táňa ; Vrbová, Kristýna ; Sikorová, Jitka ; Topinka, Jan ; Rössner ml., Pavel
The use of nanomaterials (NMs) in different areas has been rising for more than a decade. Along with this growth, there is visible development of different testing tools and approaches for measuring the actual size of nanomaterials in biological systems. Test conditions during in vitro toxicological assays are different from the standard conditions under which nanomaterials are characterized and careful evaluation of results is needed. The unique properties and range variety of NMs require the close look how the NMs behave in different dispersion medium over time. In this study we present the results of five types of well-characterized NMs (TiO2: NM-101 and NM-103, SiO2: NM-200, Ag: NM-300K and NM-302) of specific size and shape. The hydrodynamic size and Zeta potentials in suspensions were measured using a dynamic light scattering technique (DLS) (Zetasizer Nano ZS, Malvern, UK). The DLS method is suitable for spherical particles, nevertheless, all samples were measured in order to obtain a rough insight into agglomerate formation in the medium. NM300, NM302, and NM200 aggregated rapidly in the media, thus the cells would be most likely exposed to settled big aggregates then small clusters or individual particles. More stable NMs (NM100 and NM103) showed slight grow along with cultivation time or concentration corresponding to cluster formation. Cells exposed to those NMs would be in contact with small clusters and aggregates of NMs. Measured zeta potentials fluctuated around the stability limit corresponding to observed aggregation.
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Ultrafine particles and their possible role in etiology and development of neurodegenerative diseases
Topinka, Jan ; Závodná, Táňa ; Rössnerová, Andrea ; Rössner ml., Pavel
Air pollutants have been shown to cause a vast amount of different adverse health effects. These effects include impairment of many respiratory (e.g. asthma, chronic obstructive pulmonary disease) and cardiovascular (ischemic heart disease, infarction, stroke) diseases. However, in recent years, the evidence showing effects beyond the lungs and circulatory system are becoming more evident. Neurological diseases, namely Alzheimer's disease (AD) has shown to be associated with living near traffic. However, reason for this has remained unresolved until today. Our new H2020 project TUBE aims on revealing the mechanisms of action of ultrafine particles involved in neurological diseases. The TUBE consortium includes experts in areas of aerosol technology, emission research, engine and fuel research, human clinical studies, epidemiology, emission inventories, inhalation toxicology, neurotoxicology and disease mechanism studies. This enables research of resolving the effects of nanoparticles from different traffic modes for both air quality and concomitant toxic effect of these air pollutants. We will investigate adverse effects of air pollutants using cell cultures, animal exposures and volunteered human exposures as well as the material from epidemiological cohort study. These are going to be compared according to inflammatory, cytotoxic and genotoxic changes and furthermore beyond the current state of the art to neurotoxic and brain health effects. With this approach, we are aiming to a comprehensive understanding of the adverse brain effects of nanoparticles from traffic.
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Males-females differences in the spectrum of chromosomal aberrations in the group of nanocomposites production workers
Rössnerová, Andrea ; Pelcová, D. ; Ždímal, Vladimír ; Elzeinova, Fatima ; Margaryan, Hasmik ; Chvojková, Irena ; Topinka, Jan ; Schwarz, Jaroslav ; Ondráček, Jakub ; Koštejn, Martin ; Komarc, M. ; Vlčková, Š. ; Fenclová, Z. ; Lischková, L. ; Dvořáčková, Š. ; Rössner ml., Pavel
An increase in the use of nanomaterials (NM) has been witnessed in many areas of human life. Therefore, assessment of genotoxicity of NM and nanoparticles (NP) is one of the main objectives of genetic toxicology. Despite this fact, human cytogenetic studies following the exposure to NP are still rare. Moreover, no relevant information on possible differences in sensitivity to NP related to gender is available.\n\nIn this study we periodically (in September 2016, 2017 and 2018; pre-shift and post-shift each year) analyzed a group of workers (both genders), working long time in nanocomposites research, and matched controls. Aerosol exposure monitoring of particulate matter including nano-sized fractions was carried out during working shift. Micronucleus assay using Human Pan Centromeric probes, was applied to distinguish, besides the frequency of total MN in binucleated cells (BNC), also other types of chromosomal damage (losses and breaks). Moreover, whole-chromosome painting (WCP) for autosome #1 and both gonosomes (X and Y) were applied in third sampling period (2018) with the aim to identify the particular structural and numerical chromosomal aberrations.\n\nObtained results showed: (i) differences in the risk of exposure to NP related to individual working processes (welding, smelting and machining); (ii) differences in chemical composition of nano-fraction; (iii) no effect of chronic exposure of NP (total MN) opposite to significant effect of acute exposure; (iv) gender-related DNA damage differences (females seem to be more sensitive to chromosomal losses). Additional data from WCP suggested increased frequency of numerical aberrations in gonosomes.
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Photocatalytic concrete screeds with self-cleaning and antimicrobial function
Bíbová, Hana ; Šubrt, Jan ; Pližingrová, Eva ; Jakubičková, M. ; Sázavská, T. ; Dohnálek, P. ; Hykrdová, Lenka ; Jirkovský, Jaromír
Photocatalytic concrete screeds with self-cleaning and antimicrobial function have been developed and tested. These building materials contain sand grains with deposited composite TiO2/SiO2 layers. Two types of the screeds, grey and white, were prepared and their photoactivity and material characteristics were compared. Commercial TiO2 photocatalysts from several manufacturers were employed. Effects of different parameters, such as temperature of the coated sand calcination, humidity, and surface abrasion, were followed. Mechanical properties of the screeds were analyzed by SEM/XRD microscopy. Photocatalytic activity was tested by means of NOx oxidation (ISO norm 22197-1/2007). Antibacterial activity was evaluated by modified ISO norm 27447/2009 with Bacillus subtilis as a model organism.
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