Magnetic Nanoparticles: Biologically and Environmentally Suitable for In Vitro Air Pollution Exposure Studies

ORI BABER (1) Myoseon Jang (1) David Barber (1) Andrew Ghio (2)

(1) Department of Environmental Engineering Sciences, University of Florida (2) EPA, Research Triangle Park, North Carolina

     Abstract Number: 493
     Last modified: May 13, 2010

Abstract
Contemporary air pollution exposure studies using in vitro techniques are limited because they pose unnecessary biological stress to cultured cells and/or modify the chemical and physical properties of airborne matter. The purpose of our research is to investigate a novel exposure method and dosimetry using aerosolized magnetic nanoparticles (MNPs), specifically silica coated magnetic material known as MagSilica®, as a mechanism to carry particles to in vitro human airway epithelial cells. Two types of MagSilica with different amounts of magnetic material and silica were examined for biological and environmental suitability. These particles were compared to iron oxide magnetic nanoparticles with no silica imbedding. To verify the inocuity of the delivery method, we measured the concentrations of soluble iron associated with MagSilica® and iron oxide nanoparticles internally mixed with atmospheric organic compounds or inorganic acid (sulfuric acid). Various toxicological endpoints of the in vitro airway epithelial cell cultures were examined after exposure to the MNPs. These endpoints include cell associated metal content, transepithelial resistance, cell viability, production of pro-inflammatory cytokines, and induction of oxidative stress. The heterogeneous reactions of atmospheric oxidants such as O$_3, NO$_x, and SO$_x on the surface of aerosolized nano-particles were studied to test the environmental appropriateness of the delivery method. MNP methodology can be used to efficiently acquire toxicity information prior to exhaustive inhalation studies. Successful development and advancement of the procedure will enable in vitro exposure studies to examine the toxicity of various particles associated with automobile combustion, bioenergy sources, and secondary organic aerosols (SOAs).