High-resolution and High-throughput Toxicity Assessment of Ambient PM2.5 with a Microfluidic Cell Assay

ANNA KAEHR, Guillaume Aubry, Fobang Liu, Seongbin Jo, Hang Lu, Nga Lee Ng, Georgia Institute of Technology

     Abstract Number: 531
     Working Group: Health-Related Aerosols

Abstract
PM2.5 exposure is associated with both acute respiratory effects in the short term and chronic lung disease in the long term. Due to the chemical complexity and diversity of ambient aerosols, there is a need to screen a wide range of aerosol compounds for their toxicity to develop predictions on human health. As the mechanisms of aerosol damage likely depend on the aerosol properties and chemical composition, it is also useful to monitor multiple biological phenotypes to draw a more holistic understanding of lung injury. Here, we employ a microfluidic platform to assess the impact of aerosols on murine alveolar macrophages. With automatic dilution of extracted SOA, we can continuously deliver a range of doses to the macrophages which are compartmentalized for ease of single-cell analysis. We can simultaneously measure multiple biomarkers over time, including intracellular reactive oxygen species (ROS), programmed cell death activity, and mitochondrial membrane potential (MMP). With this platform, we investigate the toxicity of PM2.5 in the Atlanta metropolitan area, a location known to have influences from both biogenic and anthropogenic sources. Our preliminary results are for the winter season, a time of year that has strong influences from prescribed burns in the southeastern United States and has elevated concentrations of biomass burning organic aerosols (BBOA) compared to biogenic aerosols. This microfluidic platform can identify cell-level responses (high-resolution) while also being a more rapid and cost-effective (high-throughput) alternative to traditional well plate cell assays, improving the ability to screen a broader set of aerosols and assess their implications on human health.