Biomimetic Photo-Switches Softening Model Lipid Membranes

We report the synthesis and characterization of a novel photo-switch based on biomimetic cyclocurcumin analogous and interacting with lipid bilayer, which can be used in the framework of oxygen-independent light induce therapy. More specifically, by using molecular dynamics simulations and free energy techniques, we show that the inclusion of hydrophobic substituents is needed to allow internalization in the lipid membrane. After having confirmed that the substituents do not preclude the efficient photoisomerization, we show that the chromophore is internalized in both lipid vesicles and monomolecular film, inducing their fluidification. The irradiation of the chromophore-loaded lipid aggregate modifies their properties due to the different organization of the two isomers. In particular a competition between a fast structural reorganization and a slower expulsion of the chromophore after isomerization can be observed. This report paves the way for future investigations in the optimization of biomimetic photoswitches potentially useful in modern light-induced therapeutic strategies