Non-aqueous, zwitterionic solvent as an alternative for dimethyl sulfoxide in the life sciences

Dimethyl sulfoxide (DMSO) is widely used as a solvent in the life sciences, however, it is somewhat toxic and affects cell behaviours in a range of ways. Here, we propose a zwitterionic liquid (ZIL), a zwitterion-type ionic liquid containing histidine-like module, as a new alternative to DMSO. ZIL is not cell permeable, less toxic to cells and tissues, and has great potential as a vehicle for various hydrophobic drugs. Notably, ZIL can serve as a solvent for stock solutions of platinating agents, whose anticancer effects are completely abolished by dissolution in DMSO. Furthermore, ZIL possesses suitable affinity to the plasma membrane and acts as a cryoprotectant. Our results suggest that ZIL is a potent, multifunctional and biocompatible solvent that compensates for many shortcomings of DMSO. Dimethyl sulfoxide is a commonly used solvent, but its permeability and effect on cells is problematic. Here, an alternative solvent, a zwitterion-type ionic liquid, and its plasma membrane affinity as well as cryo-protecting property and drug-dissolution ability are reported.