“…Conformational photoswitching is a typical method for inducing reversible, site-specific structural and functional alterations , in bioactive molecules such as peptides, − protein-bound ligands, − and oligonucleotides. − A significant part of this category includes photoswitchable lipids (PSLs), capable of modifying their configuration when exposed to UV radiation. − PSLs often integrate an azobenzene moiety in their acyl chains, allowing for rapid and reversible trans-to-cis photoisomerization. ,,− The small size and hydrophobic properties of azobenzene make it suitable for lipid tail modification . When PSLs are fused to the lipid bilayer, it can affect the membrane structure, permeability, fluidity, and phase behavior under UV. − The trans-conformer with a straight chain mimics a saturated lipid, while the cis-form with a curved tail resembles an unsaturated lipid, limiting the closer approach of neighboring molecules. , This trans-to-cis conversion leads to a reduced packing density, increased membrane fluidity, and increased permeability to specific substances. ,,− This phenomenon offers an opportunity to design light-responsive liposomes that allow for controlled and sustainable drug delivery.…”