Investigation of self-association between new glycosurfactant N-acetyl-β-d-glucosaminyl-PEG-docosanate and soybean phosphatidylcholine into vesicles

This work describes the investigation of self-assembly between phosphatidylcholine-purified soybean lecithin (PC) and the new glycosylated polymeric amphiphile N-acetyl-β-d-glucosaminyl-PEG900-docosanate conjugate (C22PEG900GlcNAc). Our results indicate that a mixture of PC and C22PEG900GlcNAc undergoes spontaneous self-assembly in aqueous solution, forming vesicles with a mean diameter of 100 nm. Dynamic light scattering (DLS), transmission electron microscopy (TEM) and small-angle X-ray scattering (SAXS) were used to investigate the structure of the self-assembled vesicles. The effects of the C22PEG900GlcNAc on the molecular dynamics of the vesicleʹs PC groups were monitored by HATR-FTIR and 1H NMR. Our results indicate that PC and C22PEG900GlcNAc mixed vesicles have colloidal stability against aggregation processes. The stronger interaction of C22PEG900GlcNAc with the soybean phosphatidylcholine phosphate suggests an attractive force between this lipidic region and the nitrogen groups of the polymer. However, the enhancement of the hydrogen bonds on the PC carbonyl region may result from a discrete interaction with the hydroxyl and carbonyl regions of the C22PEG900GlcNAc. A disorder on PC carbonyl region and acyl methylene groups was observed and may be related to a C22PEG900GlcNAc-induced restriction on the lipid intermolecular contact, at interfacial and hydrophobic regions. These findings support the great potential of biosourced lipids in the design of PEG-ester carbohydrate-decorated vesicles with surfaces allowing the site-directed vectorization of active molecules through receptor–ligand binding.