Complex Mixtures
The toxic or health hazard potential of emissions from combustion processes, which are a burden both to the environment as well as to indoor atmospheres – e.g. from car engines or cigarette smoke – is often the subject of heated discussion. The toxicological investigation of such complex mixtures in-vitro has to date been considered problematic and previous standard approaches have been limited to individual substances or synthetically generated model mixtures.
These samples only poorly reflect the composition of the aerosols actually present in the real world. The ideal solution would be to analyse such atmospheres in their native composition, in order to gain true insights into or indicators of their cytotoxic and mutagenic capacity.
In response to this situation, we developed and established a new experimental method for the direct exposure of cultivated cells in the patented CULTEX® systems. In addition to the implementation of a relevant in-vitro system and suitably adapted endpoints, the exposure system must also satisfy a number of requirements:
- The generation and control of reproducible levels of the test atmosphere
- A stable and reproducible delivery of the test atmosphere
- The atmosphere should have as close as possible contact with the cells
- The system should be designed to allow extended exposure times
The CULTEX® system represents a method which makes it possible to expose, for example, human lung cells or 3D cell constructs in-vitro directly at the air/liquid interface to gases (e.g. nitrogen dioxide or ozone), complex gas mixtures like side and mainstream smoke, or diesel engine emissions in an exposure unit designed specifically for this purpose to characterise the biological effects of such a direct exposure.
This innovative technique stands out in particular for the following reasons:
- A reproducible and direct gas/cell contact between cells cultured on microporous membranes and the test atmosphere.
- Nutrification of the cells through the membrane, avoiding interaction between reactive compounds of the test atmosphere and medium components.
- Pressureless sample taking, in which the test atmosphere is passed over the test cells under predefined conditions.