Importance of material evaluation prior to the construction of devices for in vitro techniques.

The development and validation of new in vitro methods in the field of toxicology have gained more importance in recent years due to stricter guidelines for animal testing, especially in the European Union. Consequently, advances in the construction of technical devices for the exposure of cell or tissue cultures to test substances are necessary. Here, to obtain reliable results, it is important to exclusively use materials that do not interfere with the cell viability. Thus, similar to the biomaterials testing of medical devices which is regulated in the Directive 93/42/EEC, the biocompatibility of the materials has to be verified prior to the construction of such devices. We present here a novel approach for biomaterials testing which allows the quantitative and qualitative assessment of cytotoxicity of material samples. Stainless steel and silicone are often used for laboratory equipment, due to their high chemical, thermal and mechanical resistance. However, our results highlight that some types of silicone may have adverse effects on cultured cells. Moreover, special methods for the surface treatment of metals may also be a critical factor for in vitro devices. Therefore, the testing of all materials coming in contact with cell cultures is highly recommended.