title: [Establishment and application of an in vitro model for dynamic direct exposure of lung epithelial cells (A549) to airborne compounds].
abstract: OBJECTIVE
  To establish and apply a dynamic in vitro model for direct exposure of human cells to gaseous contaminants to investigate the cellular responses to airborne chemical exposures.
  
  
  METHODS
  Nitrogen dioxide (NO2) was selected as a model gas compound. Standard test atmospheres were generated (5.1 - 20.7 mg/m3), using clean air dilution method. A549 pulmonary type II-like epithelial cell lines and skin fibroblasts were grown on porous membranes. Human cells on transwell inserts were placed in horizontal diffusion chambers and exposed to various airborne concentrations of NO2 directly at the air- liquid interface for 1 h at 37 degrees C, 15 ml/min. The gasoline exhuast at different load (idle with cold start, 50% and 100% load) collected in Tedlar air bag directly exposed A549 cell for 15 min at 37 degrees C, 10 ml/min. Cytotoxicity of the test gas was investigated using the MTT, NRU (neutral red uptake) and CCK-8 assays.
  
  
  RESULTS
  Dose-dependent effects of NO2 were observed in human cells tested which resulted in a significant reduction of cell viability at different concentrations of NO2 (MTT estimated curve:gamma(MTT) = 0.989 - 0.021 chi (NO(2)) R2 = 0.84, P < 0.01; NUR estimated curve:gamma(NUR) = 1.032 - 0.026 chi (NO(2)) R2 = 0.88, P < 0.01). Gasoline exhaust exposure at different load resulted in a decreased cell viability (significantly CCK-8 and MTT levels reduction than air exposure group).
  
  
  CONCLUSIONS
  The dynamic direct exposure method can be used for in vitro inhalational and dermal toxicity studies and potentially as an new technology for biomonitoring of airborne contaminants in future occupational and environmental toxicity assessments.
authors: Tao
authors: T
authors: Yu
authors: Li
authors: L
authors: Liu
authors: Jingwei
authors: J
authors: Xiao
authors: Bin
authors: B
authors: Li
mesh_terms: D000393:Air Pollutants / Q000633:toxicity*; D002460:Cell Line; D002470:Cell Survival; D004784:Environmental Monitoring; D004847:Epithelial Cells; D005347:Fibroblasts; D006801:Humans; D066298:In Vitro Techniques; D008168:Lung / Q000166:cytology*; D009499:Neutral Red; D009585:Nitrogen Dioxide; D018675:Toxicity Tests
chemical_list: D000393:Air Pollutants; D009499:Neutral Red; D009585:Nitrogen Dioxide