title: Effect of pH and counterions on the encapsulation properties of xenon in water-soluble cryptophanes.
abstract: In the (129)Xe NMR-based biosensing approach in which the hyperpolarized noble gas is transported to biological receptors for a sensitive molecular imaging, cryptophanes are excellent xenon host systems. However to avoid formation of self-organized systems, these hydrophobic cage molecules can be rendered water soluble by introduction of ionic groups. We show that the sensitivity of xenon to its local environment and the presence of these ionic functions can lead to interesting properties. For a first water-soluble cryptophane derivative, we show that a precise monitoring of the local pH can be performed. For a second cryptophane, the presence of ionic groups close to the cryptophane cavity modifies the xenon binding constant and in-out exchange rate. The latter allows the tuning of physical properties of xenon-cryptophane interactions without resorting to a change of the cavity size. These results open new perspectives on the influence of chemical modifications of cryptophanes for optimizing the biosensor properties.
authors.affiliation: IRAMIS, SIS2M, Laboratoire Structure et Dynamique par Résonance Magnétique, UMR CEA/CNRS 3299, CEA-Saclay, 91191 Gif-sur-Yvette, France. patrick.berthault@cea.fr
authors.forename: Patrick
authors.initials: P
authors.lastname: Berthault
authors.forename: Hervé
authors.initials: H
authors.lastname: Desvaux
authors.forename: Thierry
authors.initials: T
authors.lastname: Wendlinger
authors.forename: Marina
authors.initials: M
authors.lastname: Gyejacquot
authors.forename: Antoine
authors.initials: A
authors.lastname: Stopin
authors.forename: Thierry
authors.initials: T
authors.lastname: Brotin
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Dutasta
authors.forename: Yves
authors.initials: Y
authors.lastname: Boulard
mesh_terms: D000465:Algorithms; D006863:Hydrogen-Ion Concentration; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D011083:Polycyclic Compounds; D012995:Solubility; D014230:Triazoles / Q000737:chemistry*; D014867:Water / Q000737:chemistry; D014978:Xenon / Q000737:chemistry*; D014979:Xenon Isotopes / Q000737:chemistry
chemical_list: D011083:Polycyclic Compounds; D014230:Triazoles; D014979:Xenon Isotopes; C523242:cryptophane; D014867:Water; D014978:Xenon