Pre-exposure to titanium or iron oxide nanoparticles suppresses the subsequent cellular uptake of gold nanoparticles

Cell-excreted proteins mediate the interactions of differently sized silica nanoparticles during cellular uptake

Exposure to different types of nanoparticles (NPs) results in their deposition in human bodies. While most studies have examined the cellular uptake of only one type of NP at a time, how the dynamics of NP uptake may change in the presence of other types of NPs remains unclear. We therefore investigated the interplay of two differently sized SiO2 NPs during their uptake by A549 human lung carcinoma cells. Both NPs contained a CdSeTe core, which was labeled with different Cd isotopes to differentiate between them. Our study showed that the uptake of one size of SiO2 NPs either increased or decreased with the concentration of the other size of SiO2 NPs. This variation in uptake was attributable to the concentration-dependent aggregation of SiO2 NPs, as determined by the amount of cell-excreted proteins adsorbed on the NP surface. Further, the effects of the protein corona on the attachment of SiO2 NPs to the cell surface and uptake competition between differently sized SiO2 NPs also played important roles. Cell-excreted proteins were then analyzed by proteomics. Overall, the complex interactions between coexisting NPs of different physicochemical properties and cell-excreted proteins should be considered during bio-applications and bio-safety evaluations of NPs.

Critical evaluation of the potential of ICP-MS-based systems in toxicological studies of metallic nanoparticles

The extensive application of metallic nanoparticles (NPs) in several fields has significantly impacted our daily lives. Nonetheless, uncertainties persist regarding the toxicity and potential risks associated with the vast number of NPs entering the environment and human bodies, so the performance of toxicological studies are highly demanded. While traditional assays focus primarily on the effects, the comprehension of the underlying processes requires innovative analytical approaches that can detect, characterize, and quantify NPs in complex biological matrices. Among the available alternatives to achieve this information, mass spectrometry, and more concretely, inductively coupled plasma mass spectrometry (ICP-MS), has emerged as an appealing option. This work critically reviews the valuable contribution of ICP-MS-based techniques to investigate NP toxicity and their transformations during in vitro and in vivo toxicological assays. Various ICP-MS modalities, such as total elemental analysis, single particle or single-cell modes, and coupling with separation techniques, as well as the potential of laser ablation as a spatially resolved sample introduction approach, are explored and discussed. Moreover, this review addresses limitations, novel trends, and perspectives in the field of nanotoxicology, particularly concerning NP internalization and pathways. These processes encompass cellular uptake and quantification, localization, translocation to other cell compartments, and biological transformations. By leveraging the capabilities of ICP-MS, researchers can gain deeper insights into the behaviour and effects of NPs, which can pave the way for safer and more responsible use of these materials.