Poorly soluble, low (cyto)toxic particles (PSLTs) are often regarded as one group, but it is important that these particles can be further differentiated based on their bioactivity. Currently, there are no biological endpoint based groupings for inhaled nanoparticles (NPs) that would allow us to subgroup PSLTs based on their mode of action. The aim of this study was to group NPs based on their cytotoxicity and by using thein vitro response of the endo-lysosomal system as a biological endpoint. In our study, the 15 different NPs were tested with human lung adenocarcinoma (A549)cells. The highly soluble NPs were most cytotoxic. With respect to PSLTs, only three NPs increased the cellular load of acid and phospholipid rich organelles indicating particle biopersistence. All the rest PSLTs could be regarded as low hazardous
COBISS.SI-ID: 5064015
The use of titanium suboxides, known as Magnéli phase TiOx, is expected to increase in the near future due to their desirable properties. In order to use Magnéli phase TiOx nanoparticles safely, it is necessary to know how nanoparticles interact with biological systems. In this study, the cytotoxicity of three different Magnéli TiOx nanoparticles was evaluated using human lung A549 cells and the results were compared with hazard data on two different TiO2 nanoparticles whose biological interactions have already been extensively studied. In order to investigate possible modes of particle actions, intracellular Ca2+ level, reactive oxygen species (ROS) production, and photo-oxidative disruptions of lysosomal membranes were assessed. In addition, the photocatalytic activity of Magnéli TiOx and TiO2 nanoparticles was measured. The results show that Magnéli TiOx nanoparticles increase intracellular Ca2+ but not ROS levels. In contrast, TiO2 nanoparticles increase ROS levels, resulting in a higher cytotoxicity. Although Magnéli TiOx nanoparticles showed a lower UV-A photocatalytic activity, the photo-stability of the lysosomal membranes was decreased by a greater extent, possibly due to particle accumulation inside lysosomes. We provide evidence that Magnéli TiOx nanoparticles have lower overall biological activity when compared with the two TiO2 formulations. However, some unique cellular interactions were detected and should be further studied in line with possible Magnéli TiOx application. We conclude that Magnéli phase nanoparticles could be considered as low toxic material same as other forms of titanium oxide particles.
COBISS.SI-ID: 4954959
Extracellular vesicles (EVs) isolated from biological samples are a promising material for use in medicine and technology. However, the assessment methods that would yield repeatable concentrations, sizes and compositions of the harvested material are missing. A plausible model for the description of EV isolates has not been developed. Furthermore, the identity and genesis of EVs are still obscure and the relevant parameters have not yet been identified. The purpose of this work is to better understand the mechanisms taking place during harvesting of EVs, in particular the role of viscosity of EV suspension. This study has estimated the value of the viscosity coefficient of the medium in blood plasma to be 1.2 mPa/s. It can be concluded that light scattering could be a plausible method for the assessment of EVs upon considering that EVs are a dynamic material with a transient identity.
COBISS.SI-ID: 1538312131