Mechanisms of action of ionic liquids on living cells: the state of the art

• Published in: Biophysical reviews 2020-10, Vol.12 (5), p.1187-1215
• Main Authors: Kumari, Pallavi, Pillai, Visakh V.S., Benedetto, Antonio
• Format: Article
• Language: English
• Subjects: Biochemistry; Biological and Medical Physics; Biological Techniques; Biomedical and Life Sciences; Biomolecules; Biophysics; Cell Biology; Cell membranes; Chloroplasts; DNA fragmentation; Electrolytic cells; Ionic liquids; Life Sciences; Lipids; Melt temperature; Membrane Biology; Mitochondria; Nanotechnology; Nonaqueous electrolytes; Nuclear membranes; Reactive oxygen species; Review; Reviews; Room temperature; State-of-the-art reviews; Toxicity; Viscoelasticity
• ISSN: 1867-2450; 1867-2469
• DOI: 10.1007/s12551-020-00754-w

Ionic liquids (ILs) are a relatively new class of organic electrolytes composed of an organic cation and either an organic or inorganic anion, whose melting temperature falls around room-temperature. In the last 20 years, the toxicity of ILs towards cells and micro-organisms has been heavily investigated with the main aim to assess the risks associated with their potential use in (industrial) applications, and to develop strategies to design greener ILs. Toxicity, however, is synonym with affinity, and this has stimulated, in turn, a series of biophysical and chemical-physical investigations as well as few biochemical studies focused on the mechanisms of action (MoAs) of ILs, key step in the development of applications in bio-nanomedicine and bio-nanotechnology. This review has the intent to present an overview of the state of the art of the MoAs of ILs, which have been the focus of a limited number of studies but still sufficient enough to provide a first glimpse on the subject. The overall picture that emerges is quite intriguing and shows that ILs interact with cells in a variety of different mechanisms, including alteration of lipid distribution and cell membrane viscoelasticity, disruption of cell and nuclear membranes, mitochondrial permeabilization and dysfunction, generation of reactive oxygen species, chloroplast damage (in plants), alteration of transmembrane and cytoplasmatic proteins/enzyme functions, alteration of signaling pathways, and DNA fragmentation. Together with our earlier review work on the biophysics and chemical-physics of IL-cell membrane interactions (Biophys. Rev. 9:309, 2017), we hope that the present review, focused instead on the biochemical aspects, will stimulate a series of new investigations and discoveries in the still new and interdisciplinary field of “ILs, biomolecules, and cells.”