Ionic compounds (ionic liquids)
Partitioning of ionic liquids in cell-based assays
Ionic liquids (ILs), are gaining a broad interest due to their desirable physicochemical properties and the ease of tailoring of these properties by combining cationic and anionic moieties with different substituents. They are also classified as “green” or “sustainable” chemicals because of their negligible vapor pressure and non-flammability. However, with the expanding number of studies on the toxicity and biodegradability of ILs, we are now aware that some ILs can be very hazardous. This project focuses on mechanistic investigations of modes of toxic action of a broad, structurally diverse group of ILs to support the evaluation of their environmental hazard. A further goal is to measure environmental or physiological partitioning properties such as the membrane-water or protein-water partition coefficients. Combined, these approaches will enable a re-evaluation of the reported toxicity data which considered only the nominal concentration and were based on apical endpoints. The research can be expanded to develop a prediction model for the toxicity and bioaccumulation potential of ILs so that we can have a pro-active screening of new, emerging compounds in the future.
Freely dissolved concentrations (Cfree) are a more accurate dose metric in toxicology, as they accounts for chemical partitioning and bioavailability better than nominal concentrations. By combining experimental quantification and modeling, our new study shows cell line-specific affinities of ionic liquid cations, improving hazard assessment and understanding of toxic modes of action. These findings emphasize the need for considering Cfree to avoid underestimating toxicity and to better predict environmental risks. More details can be found here: Assessing Modes of Toxic Action of Organic Cations in In Vitro Cell-Based Bioassays: the Critical Role of Partitioning to Cells and Medium Components
In the search for modes of toxic action of ILs, we recently performed the largest (cyto)toxicity screen in the open literature: 45 ILs were tested in reporter two gene assays targeting Nrf2-ARE mediated oxidative stress response (AREc32) and aryl hydrocarbon receptor activation (AhR-CALUX). Details can be found in: The mode of toxic action of ionic liquids: Narrowing down possibilities using high-throughput, in vitro cell-based bioassays
Do you want to know more about design of greener more sustainable chemicals including ionic liquids? Check our most recent publication Toward the Proactive Design of Sustainable Chemicals: Ionic Liquids as a Prime Example
Ionic liquids can be used as alternative plant protection measures which, unlike conventional pesticides, do not affect directly the insects or other pathogens (and may in this way contribute to biodiversity protection in agricultural areas) but stimulate plants to defend themselves. To find out more check out paper on New bifunctional ionic liquid-based plant systemic acquired resistance (SAR) inducers with an improved environmental hazard profile