Toxicokinetics of nanoparticles under chronic inhalation exposure (literature review)

The intensive use of nanomaterials and their unique physicochemical characteristics determine the relevance of establishing their effects on the body. Nanoparticles (NPs) are able to penetrate deep into the lungs causing pathophysiological response, but the patterns of their intrapulmonary biodistribution remain understudied. Our objective was to analyze recent publications describing the main routes of entry and pulmonary distribution of nanoparticles in mammals following inhalation exposure. We analyzed scientific papers published in peer-reviewed journals since 2000, indexed in the Scopus and Web of Science databases, and found using PubMed, Google Scholar, eLibrary, and CyberLeninka. Studies of toxicokinetics of particles larger than 100 nm were not eligible for inclusion in the review. We found unique physicochemical properties of nanoparticles and exposure duration to contribute the most to the development and course of pathological processes. Cells of the immune system, especially macrophages, play a major role in the distribution, clearance, and deposition of inhaled NPs. Elimination of nanoparticles usually occurs through the mucociliary escalator, either by phagocytosis or translocation to other organs and tissues. Conclusion. A wide range of adverse effects of nanoparticles on living systems necessitates further research concerning the patterns of their toxicokinetics and toxicodynamics.