Evaluating the cytotoxicity of ionic liquids using human cell line HeLa

Area of Science:

• Environmental Science
• Toxicology
• Materials Science

Background:

• Ionic liquids (ILs) are salts that are liquid at room temperature.
• Their tunable properties make them promising for various applications.
• Understanding their environmental impact, particularly cytotoxicity, is crucial.

Purpose of the Study:

• To evaluate the in vitro cytotoxicity of selected imidazolium-based ionic liquids.
• To investigate the influence of the anion and alkyl chain length on IL toxicity.
• To compare the toxicity of ILs with conventional organic solvents.

Main Methods:

• Cytotoxicity assays were performed on the human tumor cell line HeLa.
• Selected imidazolium ionic liquids with varying anions and alkyl chain lengths were tested.
• Half maximal effective concentration (EC50) values were determined.

Main Results:

• Toxicity of 1-n-butyl-3-methylimidazolium entities strongly depended on the associated anion, with tetrafluoroborate showing the lowest EC50.
• No clear trend in toxicity was observed with increasing alkyl chain length from methyl to n-hexyl.
• The n-decyl chain IL exhibited significantly higher hydrophobicity and a lower EC50 compared to the n-butyl analog.
• Imidazolium ionic liquids demonstrated lower effect concentrations than dichloromethane, toluene, and xylene.

Conclusions:

• Anion choice is a critical determinant of imidazolium ionic liquid cytotoxicity.
• Hydrophobicity plays a role in toxicity, especially with longer alkyl chains.
• Selected imidazolium ionic liquids present a potentially less toxic alternative to conventional organic solvents in certain applications.