Guénette Josée, Breznan Dalibor, Thomson Errol M
Environmental Health Science and Research Bureau, Health Canada, Ottawa, Ontario, Canada, K1A 0K9.
Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, Canada, K1H 8M5.
Inhal Toxicol. 2022;34(3-4):80-89. doi: 10.1080/08958378.2022.2039332. Epub 2022 Feb 25.
Growing interest in non-animal-based models has led to the development of devices to expose cells to airborne substances. Cells/tissues grown at the air-liquid interface (ALI) are more representative of lung cells/tissues compared to submerged cell cultures. Additionally, airborne exposures should allow for closer modeling of human lung toxicity. However, such exposures present technical challenges, including maintaining optimal cell health, and establishing consistent exposure monitoring and control. We aimed to establish a reliable system and procedures for cell exposures to gases at the ALI.
We tested and adapted a horizontal-flow ALI-exposure system to verify and optimize temperature, humidity/condensation, and control of atmosphere delivery. We measured temperature and relative humidity (RH) throughout the system, including at the outlet (surrogate measures) and at the well, and evaluated viability of lung epithelial A549 cells under control conditions. Exposure stability, dosimetry, and toxicity were tested using ozone.
Temperatures measured directly above wells vs. outflow differed; using above-well temperature enabled determination of near-well RH. Under optimized conditions, the viability of A549 cells exposed to clean air (2 h) in the ALI system was unchanged from incubator-grown cells. In-well ozone levels, determined through reaction with potassium indigotrisulfonate, confirmed dosing. Cells exposed to 200 ppb ozone at the ALI presented reduced viability, while submerged cells did not.
Our results emphasize the importance of monitoring near-well conditions rather than relying on surrogate measures. Rigorous assessment of ALI exposure conditions led to procedures for reproducible exposure of cells to gases.
对非动物模型的兴趣日益增长，促使了将细胞暴露于空气传播物质的装置的开发。与浸没式细胞培养相比，在气液界面（ALI）生长的细胞/组织更能代表肺细胞/组织。此外，空气传播暴露应能更接近地模拟人类肺部毒性。然而，这种暴露存在技术挑战，包括维持最佳细胞健康状态，以及建立一致的暴露监测和控制。我们旨在建立一个可靠的系统和程序，用于在ALI条件下使细胞暴露于气体。
我们测试并改进了一个水平流ALI暴露系统，以验证和优化温度、湿度/冷凝以及大气输送控制。我们测量了整个系统的温度和相对湿度（RH），包括在出口处（替代测量）和孔内，并评估了在对照条件下肺上皮A549细胞的活力。使用臭氧测试了暴露稳定性、剂量测定和毒性。
孔上方与流出物处直接测量的温度不同；使用孔上方温度能够确定孔附近的RH。在优化条件下，在ALI系统中暴露于清洁空气（2小时）的A549细胞的活力与在培养箱中生长的细胞相比没有变化。通过与靛蓝三磺酸钾反应确定的孔内臭氧水平证实了剂量。在ALI条件下暴露于200 ppb臭氧的细胞活力降低，而浸没式细胞则没有。
我们的结果强调了监测孔附近条件而非依赖替代测量的重要性。对ALI暴露条件的严格评估产生了使细胞可重复暴露于气体的程序。
