Variations of the hydrophobic–hydrophilic balance of bile salts provide derivatives with unconventional amphiphilic structure and new self assembly properties. In particular interesting stimuli responsive associations are observed in derivatives obtained by substituting the hydroxyl group in position 3 of sodium cholate with a hydrophobic aromatic group. It has been already shown that one of these compounds forms thermoresponsive gels providing a reversible transition from fibrils to tubules at 35-37 °C. Here a pH responding self assembly is reported for a new derivative, presenting a naphtilamide residue as a substituting group. It is shown that in aqueous solutions it forms short supramolecular tubules at low pH which transform into more elongated structure at high pH values. Circular dichroism and Light Scattering measurements show that a drastic rearrangement of the molecular packing take place during the transition, occurring around pH 9.0. Molecules showing a stimuli responsive self-assembly provide smart nanoscopic structures which find application in nanoscience. Due to the biological origin of their precursors, stimuli responsive bile salt derivatives could be potentially useful for bio medical nanotechnologies.
Stimuli responsive Bile Salt derivatives / Galantini, Luciano; Manghisi, N.; Di Gregorio, M.; Leggio, Claudia; Jover, A.; Meijide, F.; Pavel, Nicolae Viorel; Soto Tellini, V. H.; Alfaro Vargas, A.; Vázquez Tato, J.; Regev, O.. - ELETTRONICO. - (2011). (Intervento presentato al convegno 25° ECIS Conference tenutosi a Berlino nel 4-9 settembre).
Stimuli responsive Bile Salt derivatives
GALANTINI, Luciano;M. Di Gregorio;LEGGIO, Claudia;PAVEL, Nicolae Viorel;
2011
Abstract
Variations of the hydrophobic–hydrophilic balance of bile salts provide derivatives with unconventional amphiphilic structure and new self assembly properties. In particular interesting stimuli responsive associations are observed in derivatives obtained by substituting the hydroxyl group in position 3 of sodium cholate with a hydrophobic aromatic group. It has been already shown that one of these compounds forms thermoresponsive gels providing a reversible transition from fibrils to tubules at 35-37 °C. Here a pH responding self assembly is reported for a new derivative, presenting a naphtilamide residue as a substituting group. It is shown that in aqueous solutions it forms short supramolecular tubules at low pH which transform into more elongated structure at high pH values. Circular dichroism and Light Scattering measurements show that a drastic rearrangement of the molecular packing take place during the transition, occurring around pH 9.0. Molecules showing a stimuli responsive self-assembly provide smart nanoscopic structures which find application in nanoscience. Due to the biological origin of their precursors, stimuli responsive bile salt derivatives could be potentially useful for bio medical nanotechnologies.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
