How do lipid nanocarriers - Cubosomes affect electrochemical properties of DMPC bilayers deposited on gold (111) electrodes?

Cubosome nanocarriers are promising biomimetic drug delivery systems used in particular for highly toxic drugs in cases where decreasing unwanted side effects is especially important. The properties of electrode supported lipid bilayer prepared by the combined Langmuir-Blodgett and Langmuir-Schaefer techniques were studied using electrochemical techniques following exposure of the film - covered electrode to a solution containing phytantriol - based cubosomes. The inclusion of the carrier in the model membrane under different experimental conditions was probed and the modifications induced in the lipid organization were for the first time inferred by quantitative analysis of the responses of cyclic voltammetry (CV), AC voltammetry and Electrochemical Impedance Spectroscopy (EIS) as well as blocking assays using a redox probe in the solution. Exposure of a preformed DMPC bilayer to cubosome solution resulted in the improved barrier properties of the film reflecting disintegration of cubosomes and formation of additional phytantriol/Pluronic F-108 polymer layer on the top of the DMPC bilayer. On the other hand, formation of the layer in the presence of cubosomes in the subphase lead to an increased capacitance of the film since penetration of the lipid layers by the cubosomal phytantriol increased the porosity of the film.