Aufderheide Michaela
Department of In Vitro Toxicology, Fraunhofer Institute of Toxicology and Experimental Medicine, Nikolai-Fuchs-Str. 1, 30625 Hannover, Germany.
Exp Toxicol Pathol. 2005 Jul;57 Suppl 1:213-26. doi: 10.1016/j.etp.2005.05.019.
In vitro studies of adverse cellular effects induced by inhalable substances face a number of problems due to the difficulties in exposing cultured cells of the respiratory tract directly to test atmospheres composed of complex gases and particulate compounds. This paper discusses the characteristics of in vitro work and summarizes the use of different in vitro technologies to determine the adverse effects of inhaled pollutants. The exposure of cells to test atmospheres requires accurate control of the pollutant levels, as well as the close contact of cells and gas without interfering with the medium. Systems which rely on the solution of the gas in the medium overlay do not resemble the exposure conditions in vivo, and may not be suitable for studying, for example, the effects of poorly soluble gases. Exposure to gases or complex mixtures can be performed with roller bottles or flasks on rotating and rocking platforms and, using these techniques, the cells are periodically exposed to the test atmosphere. However, the most promising approach is based on a biphasic cell culture technique, where cells are grown on microporous membranes at an air-liquid interface. Here the cells are nutrified from the basal side of the membrane whilst the apical part with the cultivated cells is in direct contact with the test atmosphere. Based on this culture technique, different exposure systems have been developed and these are described and discussed. Exposure of cells from the respiratory tract to gases or particles is responsible for cell injury or cell activation associated with an overexpression of mRNA and the release of bioactive mediators. Therefore, in vitro studies using such a strategy, in combination with relevant and efficient exposure devices, open up new ways to test native complex gases and aerosols. Furthermore, such an experimental approach is not only suitable for cultivated cells, but it can also be used for exposing bacteria to inhalable test compounds. It is possible to analyze the mutagenic potency of in- and outdoor pollutants and several attempts have been made to determine the induction of revertants in a modified Ames assay after exposure to single gases or complex mixtures.
由于难以将呼吸道培养细胞直接暴露于由复杂气体和颗粒化合物组成的测试气氛中，可吸入物质诱导的细胞不良效应的体外研究面临许多问题。本文讨论了体外研究的特点，并总结了使用不同体外技术来确定吸入污染物的不良影响。将细胞暴露于测试气氛中需要精确控制污染物水平，以及细胞与气体的紧密接触而不干扰培养基。依赖于气体溶解在培养基覆盖层中的系统与体内暴露条件不同，可能不适用于研究例如难溶性气体的影响。可以在旋转和摇摆平台上使用滚瓶或烧瓶将细胞暴露于气体或复杂混合物中，使用这些技术，细胞会定期暴露于测试气氛中。然而，最有前途的方法是基于双相细胞培养技术，其中细胞在气液界面的微孔膜上生长。在这里，细胞从膜的基底侧获得营养，而带有培养细胞的顶端部分直接与测试气氛接触。基于这种培养技术，已经开发了不同的暴露系统，并对其进行了描述和讨论。呼吸道细胞暴露于气体或颗粒会导致细胞损伤或细胞活化，这与mRNA的过度表达和生物活性介质的释放有关。因此，使用这种策略结合相关且高效的暴露装置进行体外研究，为测试天然复杂气体和气溶胶开辟了新途径。此外，这种实验方法不仅适用于培养细胞，还可用于将细菌暴露于可吸入测试化合物。可以分析室内和室外污染物的致突变潜力，并且已经进行了几次尝试，以确定在暴露于单一气体或复杂混合物后在改良的艾姆斯试验中回复突变体的诱导情况。
