TY - JOUR
T1 - PH sensitive tubules of a bile acid derivative
T2 - A tubule opening by release of wall leaves
AU - Di Gregorio, M. Chiara
AU - Pavel, N. Viorel
AU - Jover, Aida
AU - Meijide, Francisco
AU - Vázquez Tato, José
AU - Soto Tellini, Victor H.
AU - Alfaro Vargas, Ariel
AU - Regev, Oren
AU - Kasavi, Yaron
AU - Schillén, Karin
AU - Galantini, Luciano
PY - 2013/5/28
Y1 - 2013/5/28
N2 - Tubules formed by self-assembly of organic molecules have vast potential for nanotechnology applications, and the introduction of sensitivity to stimuli into self-assembly tubules represents a particularly attractive feature. Here we report the preparation and characterization of a molecule obtained by chemical modification of a natural bile acid, a biological surfactant, that self-assembles in pH sensitive tubules in aqueous solutions. The tubules, which are rigid, single-walled and with a diameter of 60 nm, form at pH 8-9 and open up when the pH is increased. The transition is reversible, it occurs in the pH range of 9-10 with an opening mechanism that is remarkably different from those so far proposed in the literature. It involves a release of wall layers similar to leaves, and is determined by a drastic pH-triggered change in the molecular arrangement, which in turn induces a radical modification of the wall curvature. The description of the morphological transformation is provided by means of cryogenic transmission electron microscopy and represents, to our knowledge, the first detailed visualization of pH stimulated tubule opening. UV and circular dichroism spectroscopies are used to investigate the evolution at the molecular level.
AB - Tubules formed by self-assembly of organic molecules have vast potential for nanotechnology applications, and the introduction of sensitivity to stimuli into self-assembly tubules represents a particularly attractive feature. Here we report the preparation and characterization of a molecule obtained by chemical modification of a natural bile acid, a biological surfactant, that self-assembles in pH sensitive tubules in aqueous solutions. The tubules, which are rigid, single-walled and with a diameter of 60 nm, form at pH 8-9 and open up when the pH is increased. The transition is reversible, it occurs in the pH range of 9-10 with an opening mechanism that is remarkably different from those so far proposed in the literature. It involves a release of wall layers similar to leaves, and is determined by a drastic pH-triggered change in the molecular arrangement, which in turn induces a radical modification of the wall curvature. The description of the morphological transformation is provided by means of cryogenic transmission electron microscopy and represents, to our knowledge, the first detailed visualization of pH stimulated tubule opening. UV and circular dichroism spectroscopies are used to investigate the evolution at the molecular level.
UR - http://www.scopus.com/inward/record.url?scp=84877246199&partnerID=8YFLogxK
U2 - 10.1039/c3cp00121k
DO - 10.1039/c3cp00121k
M3 - Article
C2 - 23588347
AN - SCOPUS:84877246199
SN - 1463-9076
VL - 15
SP - 7560
EP - 7566
JO - Physical Chemistry Chemical Physics
JF - Physical Chemistry Chemical Physics
IS - 20
ER -