Absorption of the [bmim][Cl] Ionic Liquid in DMPC Lipid Bilayers across Their Gel, Ripple, and Fluid Phases

Published

April 26, 2022

Author(s)

Antonio Benedetto, Elizabeth Kelley

Abstract

Lipid bilayers are a key component of cell membranes and play a crucial role for life and in bio-nanotechnology. As a result, controlling their physicochemical properties holds the promise of effective therapeutic strategies. Ionic liquids (ILs) – a vast class of complex organic electrolytes – have shown a high degree of affinity with lipid bilayers and can be exploited in this context. However, the chemical physics of IL-lipid bilayer mixtures are not understood. This work focuses on the absorption of the model IL [bmim][Cl] into DMPC lipid bilayers across their gel, ripple, and fluid phases. Here, by small-angle neutron scattering, we show that (i) the IL-cations are absorbed in the lipid bilayer in all its thermodynamic phases, and (ii) the amount of IL inserted into the lipid phase increased with increasing temperature, changing from three to four IL-cations per ten lipids with increasing temperature form 10 ˚C in the gel phase to 40 ˚C in the liquid phase, respectively. An explicative hypothesis, based on the entropy gain coming from the IL hydration water, is presented to explain the observed temperature trend. The ability to control IL-absorption with temperature can be used as a handle to tune the effect of ILs on biomembranes and can be exploited in bio-nanotechnological applications.

Citation

Journal of Physical Chemistry B

Volume

126

Issue

17

Pub Type

Journals

Download Paper

https://doi.org/10.1021/acs.jpcb.2c00710

Local Download

Keywords

small angle neutron scattering (SANS), lipid bilayer, DMPC, ionic liquid

Citation

Benedetto, A. and Kelley, E. (2022), Absorption of the [bmim][Cl] Ionic Liquid in DMPC Lipid Bilayers across Their Gel, Ripple, and Fluid Phases, Journal of Physical Chemistry B, [online], https://doi.org/10.1021/acs.jpcb.2c00710, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=934117 (Accessed May 6, 2024)