Optimization of an air–liquid interface exposure system for assessing toxicity of airborne nanoparticles
The use of refined toxicological methods is currently needed for characterizing the risks of airborne nanoparticles (NPs)to human health. To mimic pulmonary exposure, we have developed an air–liquid interface (ALI) exposure system for directdeposition of airborne NPs on to lung cell cultures. Compared to traditional submerged systems, this allows more realistic expo-sure conditions for characterizing toxicological effects induced by airborne NPs. The purpose of this study was to investigate howthe deposition of silver NPs (AgNPs) is affected by different conditions of the ALI system. Additionally, the viability and metabolicactivity of A549 cells was studied following AgNP exposure. Particle deposition increased markedly with increasing aerosol flowrate and electrostatic field strength. The highest amount of deposited particles (2.2 μgcm–2) at cell-free conditions following 2 hexposure was observed for the highest flow rate (390 ml min–1) and the strongest electrostatic field (±2 kV). This was estimatedcorresponding to deposition efficiency of 94%. Cell viability was not affected after 2 h exposure to clean air in the ALI system.Cells exposed to AgNPs (0.45 and 0.74 μgcm–2)showedsignificantly(P < 0.05) reduced metabolic activities (64 and 46%, respec-tively). Our study shows that the ALI exposure system can be used for generating conditions that were more realistic for in vitroexposures, which enables improved mechanistic and toxicological studies of NPs in contact with human lung cells.Copyright ©2016 The Authors Journal of Applied Toxicology Published by John Wiley & Sons Ltd.
Beware the impact factor
A discussion on the limitations of assessing research impact, point out that our current measures of impact miss many aspects of societal relevance, and suggest a way to build a better mousetrap.