title: pH-Responsive Relaxometric Behaviour of Coordination Polymer Nanoparticles Made of a Stable Macrocyclic Gadolinium Chelate.
abstract: Lanthanide-containing nanoscale particles have been widely explored for various biomedical purposes, however, they are often prone to metal leaching. Here we have created a new coordination polymer (CP) by applying, for the first time, a stable Gd(III) chelate as building block in order to prevent any fortuitous release of free lanthanide(III) ion. The use of the Gd-DOTA-4AmP complex as a design element in the CP allows not only for enhanced relaxometric properties (maximum r1 =16.4 mm(-1)  s(-1) at 10 MHz), but also for a pH responsiveness (Δr1 =108 % between pH 4 and 6.5), beyond the values obtained for the low molecular weight Gd-DOTA-4AmP itself. The CP can be miniaturised to the nanoscale to form colloids that are stable in physiological saline solution and in cell culture media and does not show cytotoxicity.
authors.affiliation: Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and The Barcelona Institute of Science and Technology, Campus UAB, Bellaterra, 08193, Barcelona, Spain.
authors.forename: Javier
authors.initials: J
authors.lastname: Aríñez-Soriano
authors.affiliation: Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and The Barcelona Institute of Science and Technology, Campus UAB, Bellaterra, 08193, Barcelona, Spain.
authors.forename: Jorge
authors.initials: J
authors.lastname: Albalad
authors.affiliation: Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and The Barcelona Institute of Science and Technology, Campus UAB, Bellaterra, 08193, Barcelona, Spain.
authors.forename: Arnau
authors.initials: A
authors.lastname: Carné-Sánchez
authors.affiliation: Centre de Biophysique Moléculaire, CNRS, Université d'Orléans, Rue Charles Sadron, 45071, Orléans, France.
authors.forename: Célia S
authors.initials: CS
authors.lastname: Bonnet
authors.affiliation: Departament de Química, Universitat Autònoma de Barcelona, Campus UAB, Bellaterra, 08193, Barcelona, Spain.
authors.forename: Félix
authors.initials: F
authors.lastname: Busqué
authors.affiliation: Departament de Bioquímica i Biologia Molecular, Institut de Biotecnologia i Biomedicina (IBB), Campus UAB, 08193, Bellaterra, Spain.
authors.forename: Julia
authors.initials: J
authors.lastname: Lorenzo
authors.affiliation: ALBA Synchrotron, Cerdanyola del Vallès, 08290, Barcelona, Spain.
authors.forename: Jordi
authors.initials: J
authors.lastname: Juanhuix
authors.affiliation: Department of Applied Physics and Applied Mathematics, Columbia University, New York, USA.
authors.forename: Maxwell W
authors.initials: MW
authors.lastname: Terban
authors.affiliation: Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and The Barcelona Institute of Science and Technology, Campus UAB, Bellaterra, 08193, Barcelona, Spain.
authors.forename: Inhar
authors.initials: I
authors.lastname: Imaz
authors.affiliation: Centre de Biophysique Moléculaire, CNRS, Université d'Orléans, Rue Charles Sadron, 45071, Orléans, France. eva.jakabtoth@cnrs-orleans.fr.
authors.forename: Éva
authors.initials: É
authors.lastname: Tóth
authors.affiliation: Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and The Barcelona Institute of Science and Technology, Campus UAB, Bellaterra, 08193, Barcelona, Spain. daniel.maspoch@icn2.cat.|ICREA, Pg. Lluís Companys 23, 08010, Barcelona, Spain. daniel.maspoch@icn2.cat.
authors.forename: Daniel
authors.initials: D
authors.lastname: Maspoch
keywords: chelates; contrast agents; coordination polymers; gadolinium; relaxometry