STRUCTURAL TRANSITIONS IN PHOSPHOLIPID VESICLES INFLUENCED BY RHAMNOLIPIDS: EFFECTS OF CHARGE AND BILE SALTS

Rhamnolipids are an emerging option for various biological applications, such as food and drug delivery systems. However, their effects on bioinspired systems, such as phospholipid vesicles, and in biological fluids, like bile salt environments, are not yet fully understood. This study investigates the self-assembly behavior of natural rhamnolipids and their structural transitions in phospholipid vesicles and mixed micelles, specifically aiming to assess the contributions of charge modulation and the presence of bile salts in phase transitions within these systems. The composition and pH strongly affected the bilayer morphology, promoting structural transitions such as vesicle growth and micelle formation. Under basic conditions, stronger electrostatic repulsions favored micelle formation, while under acidic conditions, larger vesicles were promoted without affecting lamellarity. Finally, the impact of sugar groups on mixed micelle formation in the presence of bile salts revealed distinct structural profiles, with the micellar organization being strongly dependent on the proportion of rhamnolipids in the phospholipid vesicle formulation.