Droplet-based microfluidics for microtoxicological studies

The specific sensitivity of different organisms, cells, and tissues against chemicals, the huge number of produced and applied substances, and the combinatorial explosion of effects by the combination of substances demand new concepts for the efficient determination of toxicological dose/response relations. The generation, processing, and characterization of microdroplets of different chemical compositions enable microfluidic approaches to offer a very promising strategy for strongly miniaturized toxicological screenings. Over the last decade, several developments demonstrated the applicability of droplet-based microfluidic systems for toxicological studies. We review the current state of developments in microfluidics for toxicological applications. These have become powerful alternatives to microtiter plates and are very promising for replacing the standard methods in many fields. This article will focus on toxicological dose/response screenings with the variation of droplet composition, particularly on the possibility of generating concentrationspaces,'' as well as on the applied sensing principles of organisms and cells inside the microdroplets.