In vitro chemical risk assessment using human cells is emerging as an alternative to in vivo animal testing with reduced costs, fewer animal welfare concerns, and the possibility of greater human health relevance. In vitro inhalation toxicity testing of volatile compounds poses particular challenges. Here we report our efforts to establish a testing protocol in our own lab using the EpiAirway bronchial epithelium cell culture model and the Vitrocell 12/12 system for air-liquid interface (ALI) exposures. For purposes of method development, we used methyl iodide (MeI) as a test compound. We examined viability, cytotoxicity, and epithelial integrity responses. Dose-dependent, reproducible responses were observed with all assays. EpiAirway and BEAS-2B cytotoxicity responses to acute exposure were roughly similar, but EpiAirway was more resistant than BEAS-2B by the viability measurement, suggesting a proliferative response at low MeI concentrations. If wells were sealed to prevent evaporation, in-solution MeI concentration-response could be used to predict the response to MeI vapor within 2-fold by converting from the media- to the air-concentration at equilibrium using the blood:air partition coefficient for MeI. The long-term stability of EpiAirway cultures enabled repeated exposures over a 5-d period, which produced responses at lower concentrations than did acute exposure.

使用人体细胞进行体外化学风险评估正在成为体内动物试验的替代方案，其成本更低，动物福利问题更少，并且可能与人类健康相关性更大。挥发性化合物的体外吸入毒性测试提出了特殊的挑战。在这里，我们报告了我们在我们自己的实验室中使用 EpiAirway 支气管上皮细胞培养模型和 Vitrocell 12/12 系统进行气液界面 (ALI) 暴露建立测试协议的努力。出于方法开发的目的，我们使用甲基碘 (MeI) 作为测试化合物。我们检查了生存能力、细胞毒性和上皮完整性反应。所有测定均观察到剂量依赖性、可重复的反应。EpiAirway 和 BEAS-2B 对急性暴露的细胞毒性反应大致相似，但通过活力测量，EpiAirway 比 BEAS-2B 更具抵抗力，表明在低 MeI 浓度下有增殖反应。如果将孔密封以防止蒸发，则溶液中 MeI 浓度响应可用于通过使用血液：空气分配系数将平衡时的介质浓度转换为空气浓度来预测对 MeI 蒸气的响应在 2 倍以内梅。EpiAirway 培养物的长期稳定性使得能够在 5 天的时间内重复暴露，在比急性暴露更低的浓度下产生反应。通过使用 MeI 的血液：空气分配系数将平衡时的介质浓度转换为空气浓度，溶液中 MeI 浓度响应可用于预测对 MeI 蒸气的响应在 2 倍以内。EpiAirway 培养物的长期稳定性使得能够在 5 天的时间内重复暴露，在比急性暴露更低的浓度下产生反应。通过使用 MeI 的血液：空气分配系数将平衡时的介质浓度转换为空气浓度，溶液中 MeI 浓度响应可用于预测对 MeI 蒸气的响应在 2 倍以内。EpiAirway 培养物的长期稳定性使得能够在 5 天的时间内重复暴露，在比急性暴露更低的浓度下产生反应。