Effects of different head groups and functionalised side chains on the cytotoxicity of ionic liquids

Abstract

To enlarge the restricted knowledge about the hazard potentials of ionic liquids to men and the environment we have concentrated on systematically analysing the effects of 7 head groups, 10 side chains (mainly containing functional groups) and 4 anions on cytotoxicity. For our investigations, we used the promyelotic leukemia rat cell line IPC-81 as test system, with the reduction of the WST-1 dye as an indicator of cell viability. Our results show that most of the tested 100 ionic liquids generally exhibit a low cytotoxicity compared to previously investigated ionic liquids in consequence of their polar ether, hydroxyl and nitrile functional groups within the side chains. Those functional groups hamper cellular uptake by membrane diffusion and reduce lipophilicity based interactions with the cell membrane.In general, a low influence of the head group and a clear anion effect of the [(CF 3 SO 2 ) 2 N] 2 anion could be observed. Furthermore, we could confirm the general dependency between ionic liquid cation lipophilicity and cytotoxicity using a HPLC derived lipophilicity parameter. For one head group and for one side chain, deviations were obtained concerning this general dependency. This can be interpreted as a first hint for a more specific mode of action for these structural elements.

Physicochemical properties and toxicities of hydrophobic piperidinium and pyrrolidinium ionic liquids

“…There has been sufficient interest in the recent past on toxic effects of ionic liquids on microorganisms 24,27,28 and on mammalian cells. 22,25 We estimated the cytotoxicities of pyrridinium and piperidinium ionic liquids and they fall in the same range as imidazolium ionic liquids. 25,27 In addition, we observed that the toxicities of pyrridinium and piperidinium ionic liquids increase with an increase in the alkyl chain length, similar to that of imidazolium ionic liquids (Fig.…”

“…22,25 We estimated the cytotoxicities of pyrridinium and piperidinium ionic liquids and they fall in the same range as imidazolium ionic liquids. 25,27 In addition, we observed that the toxicities of pyrridinium and piperidinium ionic liquids increase with an increase in the alkyl chain length, similar to that of imidazolium ionic liquids (Fig. 6b) [Br] -is twice as low as that for NaBr.…”

“…There is growing interest in cytotoxicities, in aqueous environmental impact as well as in structureactivity relationship for ILs. [17][18][19][20][21][22][23][24][25][26][27][28] Only few reports have used human cancer cells. 18,22,26 For extraction of organic solutes or offensive metallic cations from water, we require highly hydrophobic ionic liquids that have very low solubility in water.…”

Room-temperature ionic liquids meet bio-membranes: the state-of-the-art

“…Their introduction into industrial processes, together with their organic character, motivated the first studies of their interaction with biomolecules and bio-organisms (Petkovic et al 2011). As a result, several studies have highlighted their toxicity on living organisms (Pretti et al 2006;Bernot et al 2005;Ranke et al 2006Ranke et al , 2007aStolte et al 2007;Kulacki and Lamberti 2008). Toxicity is also a measure of the high affinity between RTILs and biosystems.…”

Mutual Solubility of Hydrophobic Ionic Liquids and Water in Liquid-Liquid Two-phase Systems for Analytical Chemistry

“…Although the negligible volatility of ILs is one appealing point in the use of ILs in place of volatile organic solvents, the finite solubility of ILs in water has raised concern in wastewater treatments and other circumstances. [169][170][171][172][173][174][175][176][177][178][179][180][181][182][183][184][185][186][187] Since ILs are salts having certain solubility in water, the interface between an IL and water is inevitably electrified. There are a number of systems in which the phase-boundary potential across the IL|W interface plays a crucial role in determining the physicochemical characteristics of the systems.…”