Comparative characteristics of various fibrous materials in in vitro experiments

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

The Influence of Multiwalled Carbon Nanotubes on the Behavior of Mammals after Single Intrapharyngeal or Intravenous Exposure

© 2020, Pleiades Publishing, Ltd. Abstract: The toxic effects of multiwalled carbon nanotubes (MWCNTs) in mammals are important to assess due to MWCNTs are a widespread environmental pollutant. MWCNTs were tested for the effect on the behavioral functions of laboratory mice in the open field, rotarod, and elevated plus maze tests. Two possible routes of MWCNT entry into the body were examined: intrapharyngeal aspiration and intravenous administration, in order to model the most common ways of MWCNT entry, through the lungs and by assimilation from the blood through blood–tissue barriers. The potential toxin was administered once intrapharyngeally at 20 μg per mouse or intravenously at 0.2 μg per mouse. Acute and delayed effects were evaluated 24 h and 30 days after administration. Latent emotional tension and weaker exploratory reactions were observed 24 h after intrapharyngeal MWCNT aspiration. Signs of stress were still detectable 30 days after exposure. In contrast, an increase in locomotor and exploratory activities was observed 24 h after intravenous MWCNT administration. The result was explained by an inhibitory MWCNT effect on the lower respiratory tract and a potential lack of MWCNT accumulation in organs because MWCNTs were relatively large in size and could not penetrate through blood–tissue barriers

Dispersion of Single-Walled Carbon Nanotubes in Biocompatible Environments

© 2020, Pleiades Publishing, Ltd. Abstract: The unique physical and chemical properties of carbon nanotubes (CNTs), including SWCNTs (single-walled carbon nanotubes), allow their applications in many fields, including biomedicine. The optical properties of SWCNTs are attractive for application in the field of nanobiotechnology compared to MWCNTs (multi-walled carbon nanotubes). An important objective of SWCNT application for biomedical purposes is obtaining homogenous dispersions characterized by bioavailability and biocompatibility. The possibility of obtaining homogenous dispersions of different types of SWCNTs in biocompatible media for further use in different biomedical experiments and applications has been investigated. The sizes of SWCNT agglomerates in prepared dispersions were measured by the method of dynamic light scattering; bioavailability was studied by dark field microscopy in BEAS-2B bronchial epithelium cells. The dispersions were analyzed for the presence of bacterial contamination. Biocompatible and bioavailable dispersions have been obtained on the basis of cell culture media and 1% bovine serum albumin, which can be used in experiments on assessing the safety of SWCNTs at biological objects but have a number of limitations in the field of biomedicine. Dispergents based on lung surfactant components, which could be used in biomedical applications (DPPC and Survanta®), did not show efficency