title: Importance of agglomeration state and exposure conditions for uptake and pro-inflammatory responses to amorphous silica nanoparticles in bronchial epithelial cells.
abstract: Amorphous silica nanoparticles (SiNPs, 30 and 50 nm) and rhodamine-coated SiNPs (50 nm) were examined for their ability to induce pro-inflammatory responses and cytotoxicity in BEAS-2B cells under different experimental conditions. The SiNPs formed micrometre-sized agglomerates in the absence of bovine serum albumin (BSA) in the culture medium, whereas with BSA (0.1%) they were much less agglomerated. All the SiNPs induced IL-6 and IL-8 responses, as measured by ELISA and real-time PCR. The responses were more marked without BSA and higher for the rhodamine SiNPs than the plain ones. Rhodamine SiNPs were not taken up by cells during a 3-h exposure, even though cytokine mRNAs were up-regulated. In conclusion, agglomerated SiNPs induced more potent cytokine responses than the non-agglomerated ones; either due to the agglomeration state per se or more conceivably to a change in surface reactivity against cellular targets due to BSA. Furthermore, cytokine expression was up-regulated independently of SiNP uptake.
authors.affiliation: Division of Environmental Medicine, Norwegian Institute of Public Health, P.O. Box 4404 Nydalen, Oslo, Norway. maurizio.gualtieri@unimib.it
authors.forename: Maurizio
authors.initials: M
authors.lastname: Gualtieri
authors.forename: Tonje
authors.initials: T
authors.lastname: Skuland
authors.forename: Tore-Geir
authors.initials: TG
authors.lastname: Iversen
authors.forename: Marit
authors.initials: M
authors.lastname: Låg
authors.forename: Per
authors.initials: P
authors.lastname: Schwarze
authors.forename: Dagmar
authors.initials: D
authors.lastname: Bilaničová
authors.forename: Giulio
authors.initials: G
authors.lastname: Pojana
authors.forename: Magne
authors.initials: M
authors.lastname: Refsnes
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D002417:Cattle; D002461:Cell Line, Transformed; D002470:Cell Survival / Q000187:drug effects; D003470:Culture Media; D016207:Cytokines / Q000235:genetics / Q000378:metabolism*; D004847:Epithelial Cells / Q000187:drug effects*; D006801:Humans; D018613:Microscopy, Confocal; D053758:Nanoparticles / Q000737:chemistry / Q000633:toxicity*; D010316:Particle Size; D012235:Rhodamines / Q000737:chemistry / Q000493:pharmacokinetics / Q000633:toxicity; D012710:Serum Albumin, Bovine / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry / Q000493:pharmacokinetics / Q000633:toxicity*; D014867:Water / Q000737:chemistry
chemical_list: D003470:Culture Media; D016207:Cytokines; D012235:Rhodamines; D014867:Water; D012710:Serum Albumin, Bovine; D012822:Silicon Dioxide