(416c) Design and Characterization of a New, Portable in Vitro Exposure Cassette with Real-Time Monitoring for Aerosol Measurements

The toxicology of aerosols in occupational settings is often performed through collection of particles on a filter prior to reconstitution into cell culture media which can alter the biological effects. Current in vitro exposure systems require additional instruments to control temperature and humidity making the system bulky and difficult to take to the field. The Portable In Vitro Exposure Cassette (PIVEC) has been designed for personal monitoring, characterized using varying sized copper nanoparticles, tested with alveolar cells, and set-up to incorporate a real time monitor. Three differently sized copper nanoparticles were dispersed into a dry aerosol and measured gravimetrically and on a number concentration basis to determine the deposition efficiency of the PIVEC. A549 cells, a human alveolar adenocarcinoma epithelial line, were grown at the air-liquid interface and exposed to dry copper nanoparticle aerosols. Oxidative stress and cell viability were monitored post-exposure within the first 24 hours via the production of reactive oxygen species and the release of lactate dehydrogenase. The deposition efficiency ranged from 0.5% to 18% depending on method of analysis and size of particle. The PIVEC has been characterized for nanoparticles from 40-800 nm in size with preliminary toxicology testing. Oxidative stress increased over 4-fold from initial measurements within the first two hours post exposure, however there was no significant difference in cell viability at the four hour time point at deposited doses up to 1.63 mg/cm². Inclusion of an enzyme-based biosensor to perform real-time monitoring is currently ongoing. The biosensor is functionalized with cytochrome c to measure reactive oxygen species, including hydrogen peroxide and super oxides, through electrochemical detection during aerosol exposures. The PIVEC is a unique device, designed to monitor aerosols using air-liquid interface in vitro techniques including a real-time monitor for oxidative stress.