Abstract
The study of the toxicity, biocompatibility, and environmental sustainability of room-temperature ionic liquids (ILs) is still in its infancy. Understanding the impact of ILs on living organisms, especially from the aquatic ecosystem, is urgent, since large amounts of these substances are starting to be employed as solvents in industrial chemical processes, and on the other side, evidence of toxic effects of ILs on microorganisms and single cells have been observed. To date, the toxicity of ILs has been investigated by means of macroscopic assays aimed at characterizing the effective concentrations (like the EC50) that cause the death of a significant fraction of the population of microorganisms and cells. These studies allow us to identify the cell membrane as the first target of the IL interaction, whose effectiveness was correlated to the lipophilicity of the cation, i.e., to the length of the lateral alkyl chain. Our study aimed at investigating the molecular mechanisms underpinning the interaction of ILs with living cells. To this purpose, we carried out a combined topographic and mechanical analysis by atomic force microscopy of living breast metastatic cancer cells (MDA-MB-231) upon interaction with imidazolium-based ILs. We showed that ILs are able to induce modifications of the overall rigidity (effective Young's modulus) and morphology of the cells. Our results demonstrate that ILs act on the physical properties of the outer cell layer (the membrane linked to the actin cytoskeleton), already at concentrations below the EC50. These potentially toxic effects are stronger at higher IL concentrations, as well as with longer lateral chains in the cation.
| Original language | English |
|---|---|
| Pages (from-to) | 12452-12462 |
| Number of pages | 11 |
| Journal | Langmuir |
| Volume | 34 |
| Issue number | 41 |
| Early online date | 13 Sept 2018 |
| DOIs | |
| Publication status | Published - 16 Oct 2018 |
Funding
The authors thank L. Puricelli, R. Simonetta, and F. Fanalista for support in the development and testing of the nano-mechanical protocol and C. Lenardi for support in the cell-biology laboratory of C.I.Ma.I.Na. A.P. thanks the University of Milano for financial support under the projects of Piano di Sviluppo dell’Ateneo per la Ricerca 2014, Linea B: Supporto per i Giovani Ricercatori and the Transition Grant 2015/2017, Horizon 2020. A.P. also thanks the COST Action TD1002 for providing a stimulating environment for the discussion of AFM-based nanomechanics of cells and soft matter. M.G. acknowledges the Shenzhen Science and Technology Innovation Committee (JCYJ20170818160503855) for support.
Keywords
- cations
- membranes
- salts
- solvents
- Young's modulus
Access to Document
- Galluzzi-etal-Imidazolium-based-ionic-liquids-affect-morphology-and rigidity-of-living-cells
Copyright © 2018 American Chemical Society. This document is the Accepted Manuscript version of a Published Work that appeared in final form in Langmuir, after peer review and technical editing by the publisher. To access the final edited and published work see https://doi.org/10.1021/acs.langmuir.8b01554