Coating of Nanolipid Structures by a Novel Simil-Microfluidic Technique: Experimental and Theoretical Approaches

Nanolipid vesicular structures are ideal candidates for the controlled release of various ingredients, from vitamins for nutraceutical purposes to chemoterapic drugs. To improve their stability, permeability, and some specific surface properties, such as mucoadhesiveness, these structures can require a process of surface engineering. The interaction of lipid vesicles with oppositely charged polyelectrolytes seems to be an interesting solution, especially when the negatively charged liposomes are complexed with the cationic chitosan. In this work, a novel simil-microfluidic technique was used to produce both chitosan-coated vesicles and a vegan alternative composed of cholesterol-free liposomes coated by Guar Hydroxypropyltrimonium Chloride (Guar-HC). The combination between the experimental approach, based on experimental observations in terms of Z-potential, and size evolutions, and the theoretical approach, based on concepts of saturation, was the methodology applied to define the best polycation concentration to fairly cover (vegan or not) liposomes without aggregation. The smart production of coated nanolipid structures was confirmed by characterizations of morphology, mucoadhesiveness, and stability.