title: Self-Assembly Mechanism of pH-Responsive Glycolipids: Micelles, Fibers, Vesicles, and Bilayers.
abstract: A set of four structurally related glycolipids are described: two of them have one glucose unit connected to either stearic or oleic acid, and two other ones have a diglucose headgroup (sophorose) similarly connected to either stearic or oleic acid. The self-assembly properties of these compounds, poorly known, are important to know due to their use in various fields of application from cleaning to cosmetics to medical. At basic pH, they all form mainly small micellar aggregates. At acidic pH, the oleic and stearic derivatives of the monoglucose form, respectively, vesicles and bilayer, while the same derivatives of the sophorose headgroup form micelles and twisted ribbons. We use pH-resolved in situ small angle X-ray scattering (SAXS) under synchrotron radiation to characterize the pH-dependent mechanism of evolution from micelles to the more complex aggregates at acidic pH. By pointing out the importance of the COO-/COOH ratio, the melting temperature, Tm, of the lipid moieties, hydration of the glycosidic headgroup, the packing parameter, membrane rigidity, and edge stabilization, we are now able to draw a precise picture of the full self-assembly mechanism. This work is a didactical illustration of the complexity of the self-assembly process of a stimuli-responsive amphiphile during which many concomitant parameters play a key role at different stages of the process.
authors.affiliation: Sorbonne Universités, UPMC Univ Paris 06, CNRS, Collège de France UMR 7574, Chimie de la Matière Condensée de Paris, UMR 7574, F-75005 Paris, France.
authors.forename: Niki
authors.initials: N
authors.lastname: Baccile
authors.affiliation: Sorbonne Universités, UPMC Univ Paris 06, CNRS, Collège de France UMR 7574, Chimie de la Matière Condensée de Paris, UMR 7574, F-75005 Paris, France.
authors.forename: Anne-Sophie
authors.initials: AS
authors.lastname: Cuvier
authors.affiliation: ESRF - The European Synchrotron , High Brilliance Beamline ID02, 38043 Grenoble, France.
authors.forename: Sylvain
authors.initials: S
authors.lastname: Prévost
authors.affiliation: SynBioC, Department of Sustainable Organic Chemistry and Technology, Ghent University , Ghent, Belgium.
authors.forename: Christian V
authors.initials: CV
authors.lastname: Stevens
authors.affiliation: SynBioC, Department of Sustainable Organic Chemistry and Technology, Ghent University , Ghent, Belgium.
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Delbeke
authors.affiliation: SynBioC, Department of Sustainable Organic Chemistry and Technology, Ghent University , Ghent, Belgium.
authors.forename: Jan
authors.initials: J
authors.lastname: Berton
authors.affiliation: InBio, Department of Biochemical and Microbial Technology, Faculty of Bioscience Engineering, Ghent University , Coupure Links 653, 9000 Ghent, Belgium.
authors.forename: Wim
authors.initials: W
authors.lastname: Soetaert
authors.affiliation: InBio, Department of Biochemical and Microbial Technology, Faculty of Bioscience Engineering, Ghent University , Coupure Links 653, 9000 Ghent, Belgium.
authors.forename: Inge N A
authors.initials: INA
authors.lastname: Van Bogaert
authors.affiliation: InBio, Department of Biochemical and Microbial Technology, Faculty of Bioscience Engineering, Ghent University , Coupure Links 653, 9000 Ghent, Belgium.|Bio Base Europe Pilot Plant , Rodenhuizekaai 1, 9042 Ghent, Belgium.
authors.forename: Sophie
authors.initials: S
authors.lastname: Roelants