Protein-induced transformation of unilamellar to multilamellar vesicles triggered by a polysaccharide

We report on the morphological transitions of didodecyldimethylammonium bromide (DDAB) cationic vesicles and hybrid DDAB/hyaluronic acid (HA) vesicles upon addition of BSA at pH 7 where BSA is overall negatively charged. Small angle neutron scattering (SANS) is used to extract the size distributions of the nanovesicles, the thickness of the DDAB bilayers and their lamellarity. Although the HA-decorated DDAB vesicles contain the negatively charged polysaccharide the interaction with BSA appears to be more intense in comparison to bare vesicles. Characteristic peaks in the SANS patterns indicate the presence of multilamellar interfaces while the formation of multilamellar vesicles induced by BSA depends on the amount of added HA. Consequently, higher lamellarities are observed at higher BSA contents. This work demonstrates a simple methodology to tune the encapsulation of globular proteins in vesicular nanoassemblies by affecting their lamellarity and has direct implications on the application of vesicles and liposomes in protein delivery.

Automated summary

We study the morphological changes of DDAB cationic vesicles and hybrid DDAB/HA vesicles upon addition of negatively charged BSA at pH 7. SANS is used to analyze the size distributions of the vesicles, the thickness of DDAB bilayers, and their lamellarity. The interaction between BSA and HA-decorated DDAB vesicles is found to be more intense than with bare vesicles. The formation of multilamellar vesicles induced by BSA depends on the amount of added HA. This research demonstrates a simple method to control the encapsulation of globular proteins in vesicular nanoassemblies, which has important implications for protein delivery using vesicles and liposomes.