Effects of inorganic ambient particle type mimics on the differential expression of a pro-inflammatory mediator in vitro

This research examined the differential expression of intercellular adhesion molecule (ICAM)-1 by human lung alveolar epithelial cells (A549) following 18-hour incubation with less than 100 particles comprising 1-16 inorganic compounds. ICAM-1 induction is known to indicate potential health problems. Particles were created using an alternating current (ac) trap. The particles were used to address questions at the interface between atmospheric chemistry and lung cell biology. Particles that had diameters of 6.8, 3.8, and 2.6 µm, showed that the 2.6 µm size caused the highest ICAM-1 expression. When aluminium nitrate, iron nitrate, zinc nitrate, and lead nitrate were systematically added to PT-5, PT-6, PT-7, and PT-8, it was found that lead nitrate caused the most differential ICAM-1 expression on A549 cells. Particles comprising NaCl, in different physical states indicated that particles of NaCl plus carbon possessed the greatest pro-inflammation potential, suggesting that particle’s physical state was important to ICAM-1 expression.