Outils de formulation et de vectorisation de substances actives  
Self-assembly of amphiphilic biotransesterified B-cyclodextrins : supramolecular structure of nanoparticles and surface properties  
[Full paper ]
Jean-Luc Putaux, Christine Lancelon-Pin, François-Xavier Legrand, Marion Pastrello, Luc Choisnard, Annabelle Gèze, Cyrille Rochas and Denis Wouessidjewe
Langmuir 2017, 33, 7917–7928
A series of β-​cyclodextrin (βCD) amphiphilic derivs. with varying degrees of substitution were prepd. by acylating βCDs on their secondary face using thermolysin to catalyze the transesterification. After dissoln. in acetone, the βCD-​Cn derivs. (n = 8, 10, 12, 14) were nanopptd. in water, where they self-​organized into structured particles that were characterized using cryo-​transmission electron microscopy (cryo-​TEM) images and small-​angle X-​ray scattering (SAXS) data. Two types of morphologies and ultrastructures were obsd. depending on the total degree of substitution (TDS) of the parent deriv. The mols. with TDS < 5 formed nanospheres with a multilamellar organization, whereas those with TDS > 5 self-​assembled into barrel-​like (n = 8, 10, 12) or more tortuous (n = 14) particles with a columnar inverse hexagonal structure. In particular, faceted βCD-​C14 particles (TDS = 7) appeared to be composed of several domains with different orientations that were sepd. by sharp interfaces. Ultrastructural models were proposed on the basis of cryo-​TEM images and the anal. of the contrast distribution in different projections of the lattice. Complementary compression isotherm expts. carried out at the air-​water interface also suggested that differences in the mol. conformation of the series of derivs. existed depending on whether TDS was lower or higher than 5.