RESUMO
Aim: 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. Methods: Blood samples from female volunteers were processed before and after inhalation exposure. Transcriptomic mRNA and miRNA expression changes were analyzed. Results: We detected large interindividual variability, 90 significantly deregulated mRNAs, and 4 miRNAs when samples of participants before and after dental nanocomposite grinding were compared. Conclusion: 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.
What is this article about? 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.What were the results? 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.What do the results of the study mean? 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.
RESUMO
Colistimethate sodium (CMS) for treatment of lung infections in cystic fibrosis patient was transformed into a dry powder for inhalation by spray drying. Design of Experiment was applied for understanding the role of the spray-drying process parameters on the critical quality attributes of the CMS spray-dried (SD) powders and agglomerates thereof. Eleven experimental SD microparticle powders were constructed under different process conditions according to a central composite design. The SD microparticles were then agglomerated in soft pellets. Eleven physico-chemical characteristics of SD CMS microparticle powders or agglomerates thereof were selected as critical quality attributes. The yield of SD process was higher than 75%. The emitted fraction of agglomerates from RS01 inhaler was 75-84%, and the fine particle fraction (particles <5 µm) was between 58% and 62%. The quality attributes of CMS SD powders and respective agglomerates that were significantly influenced by spray-drying process parameters were residual solvent and drug content of the SD microparticles as well as bulk density and respirable dose of the agglomerates. These attributes were also affected by the combination of the process variables. The air aspiration rate was found as the most positively influential on drug and solvent content and respirable dose. The residual solvent content significantly influenced the powder bulk properties and aerodynamic behavior of the agglomerates, i.e. quality attributes that govern drug metering in the device and the particles lungs deposition. Agglomerates of CMS SD microparticles, in combination with RS01 DPI, showed satisfactory results in terms of dose emitted and fine particle fraction.
