Transcriptome changes in humans acutely exposed to nanoparticles during grinding of dental nanocomposites

<b>Aim:</b> Today, there is a lack of research studies concerning human acute exposure to nanoparticles (NPs). Our investigation aimed to simulate real-world acute inhalation exposure to NPs released during work with dental nanocomposites in a dental office or technician laboratory. <b>Methods:</b> Blood samples from female volunteers were processed before and after inhalation exposure. Transcriptomic mRNA and miRNA expression changes were analyzed. <b>Results:</b> We detected large interindividual variability, 90 significantly deregulated mRNAs, and 4 miRNAs when samples of participants before and after dental nanocomposite grinding were compared. <b>Conclusion:</b> The results suggest that inhaled dental NPs may present an occupational hazard to human health, as indicated by the changes in the processes related to oxidative stress, synthesis of eicosanoids, and cell division. We searched for a possible impact of acute inhalation exposure to nanoparticles (NPs) released during the grinding of dental nanocomposites used for teeth reconstruction. The exposure design utilized in our study simulated the acute exposure of the dental staff to the NPs. Our research fills the gaps in knowledge in the field of acute human inhalation exposure to dental nanocomposites. Results indicate that the impact of exposure to NPs is dependent on the style of working as well as on the interindividual biological variability among study subjects. Changes in expression levels of genes associated with an increase of oxidative stress, synthesis of eicosanoids (signaling molecules related to e.g., immune responses), and cell division were detected. All the observed changes may contribute to the pathogenesis of neurodegenerative disorders, carcinogenesis, or problems during pregnancy. Occupational exposure to inhaled NPs, including those generated in dental practice can pose a significant health risk, and protective measures when working with these materials should be considered. More research is needed to compare our results with chronic (long-term) exposure to similar materials to show the hazards related to their inhalation. The experimental design simulated the work of dental personnel during teeth repair. The study investigated the possible impact of acute inhalation exposure to nanoparticles (NPs) released during the grinding of dental nanocomposites on transcriptome changes. Analyses of the differential mRNA and miRNA expression were performed. Large interindividual variability in gene expression changes after exposure was detected. Significant deregulation of <i>DDIT4</i>, <i>PER1,</i> and <i>GPR124</i> was detected when sampling was compared after and before exposure. Deregulation of hsa-miR-15b-5p, hsa-miR-6861-3p, hsa-miR-548o-3p, and hsa-miR-3913-5p was observed when comparing post- and pre-shift sampling. Individual occupational health risks to NP exposure led to the alteration of several biological pathways. Increased oxidative stress, synthesis of eicosanoids, or cell division may contribute to the pathogenesis of neurogenerative disorders, and carcinogenesis after NP exposure.