title: Polystyrene nanoparticle trafficking across alveolar epithelium.
abstract: We investigated trafficking of polystyrene nanoparticles (PNP; 20 and 100 nm; carboxylate, sulfate, or aldehyde-sulfate modified [negatively charged] and amidine-modified [positively charged]) across rat alveolar epithelial cell monolayers (RAECM). Apical-to-basolateral fluxes of nanoparticles were estimated as functions of apical PNP concentration ([PNP]) and temperature. Uptake of nanoparticles into RAECM was determined using confocal microscopy. Fluxes increased as charge density became less negative/more positive, with positively charged PNPs trafficking 20-40 times faster than highly negatively charged PNP of comparable size. Trafficking rates decreased with increasing PNP diameter. PNP fluxes tended to level off at high apical [PNP]. Fluxes at 4 degrees C were significantly lower than those at 37 degrees C. Confocal microscopy revealed nanoparticles localized to cell cytoplasm, whereas cell junctions and nuclei appeared free of PNP. These data indicate that (1) trafficking of PNP across RAECM is strongly influenced by charge density, size, and temperature, (2) PNP translocate primarily transcellularly, and (3) PNP translocation requires cellular energy.
authors: Mork Family Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, California 90033, USA. nyaghoob@usc.edu
authors: Nazanin R
authors: NR
authors: Yacobi
authors: Lucas
authors: L
authors: Demaio
authors: Jiansong
authors: J
authors: Xie
authors: Sarah F
authors: SF
authors: Hamm-Alvarez
authors: Zea
authors: Z
authors: Borok
authors: Kwang-Jin
authors: KJ
authors: Kim
authors: Edward D
authors: ED
authors: Crandall
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D004058:Diffusion; D008297:Male; D008422:Materials Testing; D053758:Nanoparticles / Q000737:chemistry*; D011137:Polystyrenes / Q000737:chemistry* / Q000493:pharmacokinetics*; D011650:Pulmonary Alveoli / Q000737:chemistry* / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D020545:Respiratory Mucosa / Q000737:chemistry* / Q000378:metabolism*
chemical_list: D011137:Polystyrenes