The concept of “3Rs” (refinement, reduction, and replacement) has become widespread in toxicological studies. 3D cell models are a further development of traditional 2D models. In the current study, 3D models of the human respiratory system consisting of BEAS-2B bronchial epithelial cells and MRC5-SV40 lung fibroblasts are developed. The results of studying the toxicity of carbon nanotubes (CNTs) using advanced 3D models demonstrate the absence of proapoptotic and profibrogenic effects at concentrations corresponding to the reference exposure level. However, starting at a CNT concentration of 20 μg/mL, well above concentrations corresponding to the reference exposure level, signs of oxidative stress are detected in the cell models. 3D cell models can be recommended as a more objective screening method for assessing the toxicity of CNTs when moving from traditional in vitro experiments to in vivo studies.

The question of the genotoxic effect of nanomaterials, including carbon-containing ones, is of concern, since mutations of critical genes can cause carcinogenesis. One example of the potential carcinogenic effect of carbon-containing nanomaterials is multi-walled carbon nanotubes MWCNT‑7, classified by the International Agency for Research on Cancer as a possible human carcinogen. The purpose of the study is to substantiate methodological approaches to assessing the genotoxicity of industrial carbon-containing nanomaterials. Methods. Methodological approaches were developed based on experiments in vitro to assess the toxicity of MWCNTs Taunit-M and SWCNTs TUBALLTM in BEAS‑2B and A549 human respiratory system cells. In the study, two tests, MTS assay and LDH assay, which evaluate different mechanisms: a violation of metabolic processes in cells and damage to cell membranes, were used to determine the cytotoxic properties. Genotoxicity was assessed using the DNA comet assay. Results. Study planning begins with determining the concentration range for in vitro studies, taking into account occupational exposures. The cytotoxic range for the studied types of CNTs was determined using two tests. Genotoxicity was assessed at non-cytotoxic concentrations of CNTs corresponding to industrial exposures, 0.0006 μg/mL with incubation for 72 hours; the results of the DNA comet assay showed no signs of CNT genotoxicity against BEAS‑2B and A549 cells. Conclusion. The evaluation of CNT genotoxicity is carried out using the DNA comet assay at non-cytotoxic concentrations of CNTs with an experiment duration of at least 72 hours after obtaining data on the range of CNT cytotoxic effects evaluated using at least two tests.

Introduction. In the present study, a comparative assessment of the toxic effects of industrial single-walled and multi-walled carbon nanotubes (SWCNT and MWCNT) at doses corresponding to industrial exposures on BEAS-2B and A549 cells was carried out. Materials and methods. The size distribution of SWCNT and MWCNT agglomerates in dispersions was estimated by dynamic light scattering and transmission electron microscopy. Cytotoxicity was assessed using a MTS test and LDH assay. The interaction of CNTs with cells was visualized using dark-field and transmission electron microscopy. Results. Cytotoxic effects of pristine SWCNT and MWCNT in concentrations of 50-200 μg/ml and purified SWCNT in the range of 25-200 μg/ml were found in BEAS-2B cells. SWCNT and MWCNT were found to penetrate into the cytoplasm of both BEAS-2B and A549 cells, while MWCNT are more often revealed in the intracellular content as vacuolized clusters, and single SWCNT and agglomerates are visualized in the cytoplasm without a tendency to vacuolization. Limitations. CNT were introduced into cells in the form of dispersions, where both single nanotubes and their agglomerates were found. The calculation of CNT concentrations for introduction into cells was based on computer simulation. Conclusion. Further study of the mechanisms of cytotoxic and genotoxic effects of different types of carbon nanotubes (CNT) may contribute to the identification of MWCNT and SWCNT specific effects on the cells of the respiratory system to develop methodological approaches to the safe use of CNT.

AIM: to study the role of fine suspended particles in the atmospheric air in the formation of allergic, non-allergic and mixed phenotypes of bronchial asthma in adults. METHODS: The analysis of atmospheric air pollution by fine particles in Kazan was carried out according to the database of social and hygienic monitoring of the Center for Hygiene and Epidemiology in the Republic of Tatarstan for 20142020. To study the relationship between the level of atmospheric air pollution with fine particles and bronchial asthma in adults (1865 years old), a retrospective analysis of the incidence of bronchial asthma (ICD-10 codes J45.0, J45.1, J45.8) was carried out during the same period among the population of Kazan. The regional medical information system "Electronic Health of the Republic of Tatarstan" was used. Statistical modeling was carried out using the method of mixed models based on the Poisson distribution or the negative binomial distribution. RESULTS: The average annual absolute risk of bronchial asthma in the adult population of Kazan was 0.51 per 100 people aged 1865 years, an increase of 0.09 per 100 people (17.6%) per year (p=0.039). An increase in the annual maximum concentrations of PM2,5 by 10 g increased the absolute risk of non-allergic bronchial asthma by 0.066 per 100 people aged 1865 years (p=0.043). Similar dependences, but without statistical significance at the level of p 0.05, were found for such exposure parameters as the mass concentration of РМ10 and the mass of particles deposited in the tracheobronchial and alveolar sections of the lungs. For allergic and mixed asthma, no statistically significant relationships with mass concentrations and deposited doses of suspended particles were found. CONCLUSION: Air pollution with fine suspended particles increases the risk of developing a non-allergic phenotype of adult bronchial asthma, which may be associated with specific pathogenetic mechanisms, including the reaction of the epithelium to the deposition of fine particles.

Aim. Comparative assessment of the effect of fibrous materials on cell cultures RAW264.7 and BEAS-2B. Methods. The effects of various fibrous materials single-walled carbon nanotubes of two types (SWCNT-1 and SWCNT-2), differing in morphological characteristics, and chrysotile asbestos as a positive control was assessed on two cell lines macrophages RAW 264.7 and human bronchial epithelium BEAS-2B cells. The studied materials concentration range for experiments on cells was selected taking into account the SWCNT content in the air of the working area and the subsequent modeling of SWCNT deposition in the human respiratory tract. Suspensions of the studied materials were prepared based on cell culture media by ultrasonication. Cytotoxicity assessment after 48 hours of incubation was performed by using the MTS colorimetric assay. The expression level of apoptosis markers was assessed by immunoblotting using the corresponding monoclonal antibodies. Visualization of SWCNT-1, SWCNT-2 and chrysotile asbestos in BEAS-2B cell cultures was carried out by improved dark-field microscopy. Results. According to dark-field microscopy, all the studied fibrous materials were found on the surface or cytoplasm of the cells. SWCNT and chrysotile asbestos did not have a direct cytotoxic effect in the MTS assay and did not induce apoptosis according to the results of Western blotting in cell cultures of RAW264.7 macrophages and BEAS-2B bronchial epithelium. In the cells of the bronchial epithelium (BEAS-2B) that showed greater sensitivity, a slight increase in the expression of pro-apoptotic protein PARP, which was more pronounced for shorter SWCNT-2, was revealed. Conclusion. Both types of SWCNTs, despite the differences in morphological characteristics, demonstrated similar effects in in vitro experiments; this result, with its further verification, can have an important practical application in justifying approaches to determining the safety criteria for single-walled carbon nanotubes as a class of nanomaterials of the same type.

Abstract: Introduction. Air pollution with particulate matter (PM) is a serious global problem. In the Russian Federation, regular field measurements of PMs in the ambient air are carried out only in a number of cities, and the data, as a rule, are not systematized. Aim of the study: retrospective analysis of the data set on concentrations of fine particles in the ambient air of the city of Kazan. Methods. Retrospective analysis of pollution by fine fractions of suspended solids in the ambient air of Kazan in the period from 2016 to 2020 has been carried out. To study the effect of individual factors (time period (year), measurement time during the day, climatic conditions, the presence of other pollutants) on the pollution levels PM 10 and PM 2.5, regression analysis was applied based on the method of mixed models. Results. The PM 10 concentrations remained stable over a 5-year period, while the PM 2.5 concentrations decreased. At the same time, an increase in the maximum annual concentrations of both fractions was observed. The concentrations of PM 10 and PM 2.5 significantly depended on weather factors. The presence of nitrogen oxides and organic carbon in the ambient air was associated with significantly higher concentrations of PM 10 and PM 2.5. Conclusion. A statistically significant upward trend in the dynamics of the years of the maximum annual values for both fractions of suspended particles can increase health risks. Secondary pollutants (nitrogen oxides, organic carbon) is an important factor for the formation of secondary particles in the ambient air. Implementation of preventive measures in relation to industrial emissions, regional urban planning policy and a scientifically based program of social and hygienic monitoring are the most important tools for effective management of health risks caused by exposure to fine particles.

The review presents up-to-date information on the health effects of ambient fine particulate matter, obtained in large cohort epidemiological studies, as well as in meta-analysis of pooled data. In addition, it summarizes the current data on the potential pathological mechanisms and existing monitoring systems. The literature search used the Scopus, PubMed, Russian Science Citation Index databases for 19902020. The results of epidemiological studies carried out in different countries indicate that fine particles in ambient air pose a serious threat to health. Scientific publications assessing the health impact of particulate matter show a wide range of adverse effects from the increasing incidence of upper and lower respiratory tract diseases, including exacerbations of bronchial asthma, pneumonia, chronic obstructive pulmonary disease, to a high incidence of myocardial infarction, strokes, diabetes mellitus type 2, as well as an increase in overall mortality from natural causes, mainly mortality from respiratory diseases, cardiovascular and cerebrovascular diseases, lung cancer. The effects of short-term exposures are described in more detail, while the effects of long-term exposure to fine particles are not well understood. Potential mechanisms of the harmful effects of fine particulate matter include oxidative stress, inflammatory reactions, disorders of autonomic regulation and heart rhythm, fine particles translocation through the alveolar barrier into the vascular bed with endothelial damage and thrombus formation, and genotoxicity. Ambient fine particulate matter is a manageable risk factor, and reductions in air pollution will have a significant impact on public health outcomes.

Investigation of the effect of single-walled carbon nanotubes showed the absence of cytotoxic activity in cell cultures of RAW 264.7 and BEAS-2B and a slight apoptogenic effect of the studied materials on BEAS-2B cells

With the growing global market of nanocarbon materials, including single-wall nanotubes (SWCNTs), the number of people that may be exposed to carbon nanotubes (CNTs) in the form of aerosols is growing as well. In vitro methods are a promising means for obtaining an accelerated evaluation of SWCNT toxicity. Toxic effects due to SWCNTs have been investigated in the last decade using various types of cell cultures, but conclusions about their toxicity are not unequivocal. In a number of studies, dose-dependent effects such as cytotoxicity, reduction in cell viability, inhibition of cell proliferation, apoptosis, nitric oxide release, oxidative stress, and a reduction in the level of antioxidants have been reported. Other studies find little to no cytotoxic effects of SWCNTs on different cell cultures. To date, there is no ambiguity in the findings on the comparative toxicity of SWCNTs and multiwall CNTs (MWCNTs). While some authors report that SWCNTs exhibit considerable cytotoxicity, others find no considerable toxicity associated with the two types of CNTs. Finding an optimal route for preparing stable SWCNT dispersions for in vitro studies is an important methodological problem in researching SWCNT toxicity.