Validation of the CULTEX® Radial Flow System as an in vitro method for screening acute inhalation toxicity of inhalable dusts
The Project Team:
- Dirk Steinritz, Amelie Tsoutsoulopoulos,
Bundeswehr Institute of Pharmacology and Toxicology, Munich, Germany
- Andreas Breit, Katrin Gohlsch, Harald Mückter, Thomas Gudermann
Walther-Straub-Institute of Pharmacology and Toxicology, Ludwig-Maximilians-Universität, Munich, Germany
- Sebastian Hoffmann
seh consulting + services, Paderborn, Germany
- Michaela Aufderheide¹, Niklas Möhle², Olaf Krischenowski¹
Cultex Technology GmbH¹( former Cultex Laboratories GmbH²), Hannover, Germany
Although cell-based test systems are already used in a large number of studies for the toxicological evaluation of substances, their significance for the evaluation of airborne particles is limited due to the prevailing non-physiological exposure modalities (submersible cultures) and must be regarded as artificial. We eliminate this limitation by directly exposing human lung epithelial cells at the air-liquid interface to dusts using the CULTEX® Radial Flow System (RFS) in vitro method for the purpose of screening substances for their acute inhalation hazard.
In a research project funded by the BMBF (BMBF 0315710), this procedure was examined with regard to its technical robustness by establishing it in various laboratories. The transferability of the method, its variability within and between laboratories, its stability and reproducibility were promising.
Based on this pre-validation exercise, in a second project (BMBF 031A581A) the in vitro methods was validated in three independent laboratories according to international requirements. Twenty chemicals, for which a dusty atmosphere can be generated and with available in vivo reference data, were independently selected based on pre-defined criteria. These chemicals were coded and tested in the three laboratories, 13 of the 20 being tested in three independent experiments.
Within-laboratory reproducibility was on average at least 92%, while a between-laboratory reproducibility of 90% was obtained. The overall concordance was 85% (17/20), with two chemicals classified falsely as positive, resulting in a specificity of 83% (10/12) and one chemical classified falsely as negative resulting in a sensitivity of 88% (7/8).
This performance qualifies the test method as a transferable, reproducible and well predictive test method to screen inhalable dusts for their acute inhalation hazard, which has the potential to be expanded to other chemical atmospheres.