Interactions of surfactants with biomimetic membranes-2. Generation of electric potential with non-ionic surfactants

Authors: KOCHERGINSKY, NIKOLAI - University Of Illinois; Sharma, Brajendra - Bk

Submitted to: Membranes
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/14/2023
Publication Date: 3/18/2023
Citation: Kocherginsky, N.M., Sharma, B.K. 2023. Interactions of surfactants with biomimetic membranes-2. Generation of electric potential with non-ionic surfactants. Membranes. https://doi.org/10.3390/membranes13030353.
DOI: https://doi.org/10.3390/membranes13030353

Interpretive Summary: Membranes are barriers, which selectively allow for passage of certain substances while inhibiting passage of others. When the substance that passes through biological membranes is charged, it leads to the generation of electric potentials across the membrane. Earlier, we developed artificial membranes which imitate the properties of biological membranes. One would expect no generation of electric potential across any membrane using uncharged surfactants. While studying the interactions of various uncharged surfactants with biomimetic membranes, we unexpectedly observed the generation of such electric potential across the membrane. The effect we describe may be used in the determination of surfactant concentration using a cheaper method than currently used and help with a fundamental understanding of noncharged drugs with biological membranes, thereby benefitting scientists working in the industry, academia, and regulatory agencies. The approach will be extended to the noncharged biobased surfactants, which will improve the utilization of feedstocks used for surfactants, such as vegetable oils.

Technical Abstract: We describe how noncharged surfactants lead to electric effects interacting with biomimetic membranes made of nitrocellulose filters impregnated with fatty acid esters. At a surfactant concentration as low as 64 micromoles in one of the solutions, they led to transient formation of transmembrane electric potential. Maximum changes of this potential are proportional to the log of uncharged surfactant concentration when it changes by three orders of magnitude. The effect may be used in determining the concentration of these surfactants in solutions using a cheaper method and may imitate interactions of some drugs with biological membranes. We explain this nontrivial effect in terms of the suggested earlier physicochemical mechanics approach and transient changes of membrane permeability for inorganic cations.