title: Impact of amphiphilic biomass-dissolving ionic liquids on biological cells and liposomes.
abstract: The toxicity of some promising biomass-dissolving amidinium-, imidazolium-, and phosphonium-based ionic liquids (ILs), toward two different cell lines, human corneal epithelial cells and Escherichia coli bacterial cells, was investigated. In addition, dynamic light scattering (DLS) and ζ potential measurements were used to study the effect of the ILs on the size and surface charge of some model liposomes. Capillary electrophoresis (CE) was used for determination of the electrophoretic mobilities of the liposomes and for determination of the critical micelle concentration (cmc) of the ILs. The toxicity of the phosphonium ILs was highly dependent on the longest linear chain of the IL, due to increasing hydrophobicity, with the long-chain phosphonium ILs being toxic while the shorter-chain versions were significantly less toxic or not toxic at all. Amidinium and imidazolium ILs showed no significant effect on the cells, within the concentration range used. Moreover, the more hydrophobic ILs were found to have a major effect on the surface charges and size distributions of the model liposomes, which can lead to disruption of the lipid bilayer. This indicates that the cytotoxicity is at least to some extent dependent on direct interactions between ILs and the biomembrane.
authors.affiliation: Department of Chemistry and ∥Laboratory of Organic Chemistry, Department of Chemistry, University of Helsinki , A. I. Virtasen Aukio 1, Post Office Box 55, FIN-00014 University of Helsinki, Finland.
authors.forename: Suvi-Katriina
authors.initials: SK
authors.lastname: Mikkola
authors.forename: Alexandra
authors.initials: A
authors.lastname: Robciuc
authors.forename: Jana
authors.initials: J
authors.lastname: Lokajová
authors.forename: Ashley J
authors.initials: AJ
authors.lastname: Holding
authors.forename: Michael
authors.initials: M
authors.lastname: Lämmerhofer
authors.forename: Ilkka
authors.initials: I
authors.lastname: Kilpeläinen
authors.forename: Juha M
authors.initials: JM
authors.lastname: Holopainen
authors.forename: Alistair W T
authors.initials: AW
authors.lastname: King
authors.forename: Susanne K
authors.initials: SK
authors.lastname: Wiedmer
mesh_terms: D018533:Biomass; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D019075:Electrophoresis, Capillary; D004926:Escherichia coli / Q000187:drug effects; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D052578:Ionic Liquids / Q000737:chemistry* / Q000633:toxicity*; D008081:Liposomes / Q000737:chemistry*; D012995:Solubility
chemical_list: D052578:Ionic Liquids; D008081:Liposomes