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Molecular assemblies and complex systems

par Frapart - publié le , mis à jour le


A. Self-assembled polymetallic complexes

Polynuclear lanthanide compounds can be advantageously prepared using a supramolecular synthetic approach 10.
The preparation of self-assembled stable and water-soluble systems, where many factors must be taken into account, is a difficult task. In this context, an effort has been made in the design and synthesis of suitable ligands to provide and characterize precursors (polytopic ligands and their complexes) for imaging applications. Detailed thermodynamic speciation studies of supramolecular complexes with different lanthanide cations are carried out by NMR and different spectroscopic methods.

Supramolecular Complexes of Lanthanides 9

B. Modified Oligonucleotides

Novel families of original oligonucleotides are being developed to provide tools for basic research, in vitro diagnostics, biological imaging, and potential therapeutic agents.

Achieving these different objectives requires the use of oligonucleotides, which must have a number of properties. Depending on the application, the oligonucleotides must in fact have several of the following properties : forming specific and stable complexes with their targets, inducing irreversible modifications of the targets by bridging or cleavage, producing a modified signal in the presence of targets that can be used as evidence interaction. Moreover, in the case of applications in cell culture and in vivo, they must be stable towards nucleases and be capable of reaching their targets inside cells 11.
In order to confer appropriate properties on the oligonucleotides depending on the applications, we chemically modify their structural elements (nucleic bases, sugars, internucleotide linkages). To these oligonucleotides may be attached various ligands : intercalating and / or reactive molecules, peptides, lipophilic molecules, topoisomerase inhibitors, detectable fluorescent markers in the visible and NIR ...). The development of conjugates possessing optimal properties depends on the binding parameters between the two entities (binding positions on the oligonucleotide and the ligand, length and nature of the linker). The chemical synthesis of these new series of oligonucleotides requires the development of new reagents and synthetic methods.

Examples of oligonucleotides modifications
  • 9 - Zebret S. ; Vögele E., Klumpler T. and Hamacek J.
    Designing Artificial 3D Helicates : Unprecedented Self-Assembly of Homo-Octanuclear
    Tetrapods with Europium. Chem. Eur. J. (2015) 21, 6695-6699 - doi : 10.1002/chem.201500006
  • 10 - Hamacek J.
    Self-assembly Principles of Helicates, in Metallofoldamers : Supramolecular Architectures from Helicates to Biomimetics. Eds. : Albrecht M. and, Maayan G., Wiley (2013) - doi : 10.3389/fchem.2013.00015
  • 11 - Asseline U., Goncalves C., Pichon C. and Midoux M.
    Improved nuclear delivery of antisense 2’-Ome RNA by conjugation with the histidine-rich peptide H5WYGarticle. J. Gene Med. (2014) 16, 157-165 - doi : 10.1002/jgm.2773

Relevant publications

  • Vuillamy A., Zebret S., Besnard C., Placide V., Petoud S. and Hamacek J.
    Functionalized Triptycene-Derived Tripodal Ligands : Privileged Formation of Tetranuclear Cage Assemblies with Larger Ln(III). Inorg. Chem. (2017) 56, 2742-2749 - doi : 10.1021/acs.inorgchem.6b02900.
  • Hamacek J. and Vuillamy A.
    Controlling the Structures of Lanthanide Complexes in Self-Assemblies with Tripodal Ligands. Eur. J. Inorg. Chem., (2017) - doi : 10.1002/ejic.201701075.
  • El Aroussi B. and Hamacek J.
    Understanding the Speciation of Ln(III) Complexes with Octadentate Tripodal Ligands. New J. Chem. (2017) 41, 4390-4399 - doi : 10.1039/C7NJ00088J
  • Zebret S., Vogele E., Besnard C. and Hamacek J.
    Synthetic routes to large tripodal organic receptors and the structural characterisation of intermediates. Tetrahedron (2016) 72, 928-935 - doi : 10.1016/j.tet.2015.12.048

Group members

HAMACEK Josef Professor, University of Orleans, Group thematic leader @

ASSELINE Ulysse Senior CNRS researcher @