2022 is the year of the France-Portugal cooperation, organized by the French and Portuguese Ministries for Europe, Foreign Affairs and Culture.
This “France-Portugal 2022” season is an opportunity to highlight many events marking the cooperation between the two countries, including several in the field of Higher Education and Research.
In this context, the Ministry of Higher Education, Research and Innovation and the Academy of Sciences are pleased to propose a scientific prize which distinguishes existing cooperation between French and Portuguese teams, and to offer them an opportunity to deepen the cooperation in the years to come. The four prizes awarded in 2022 cover all scientific disciplines.
In this frame, the collaboration carried out for many years by Eva Jakab Toth with the University of Coimbra has been rewarded with the Mariano Gago Prize. This collaboration concerns the development of imaging agents based on metalloporphyrins for the detection of tissue redox states.
The official award ceremony helded at the Academy of Sciences on Tuesday, June 21, 2022.
Manganese(II) complexes meet increasing interest in biomedical applications, in particular as potential Magnetic Resonance Imaging contrast agents with a better biocompatibility and safety profile than the currently used gadolinium(III) chelates. However, we severely lack chelating ligands that enable high MnII complex stability and especially good selectivity for manganese(II) versus zinc(II), the most relevant biological competitor. In an article published in Angewandte Chemie Int. Ed., the “Metal complexes and MRI” group in collaboration with the group of Peter Comba at the University of Heidelberg, has identified novel cage molecules which, for the first time, satisfy these criteria. The bispidine derivative ligands provide rigid and large coordination cavities that perfectly match the slightly larger size of MnII, yielding eight-coordinate MnII complexes with record stabilities. In contrast, the smaller ZnII ion cannot accommodate all ligand donors, resulting in highly strained and less stable six-coordinate complexes.
Combined theoretical and experimental data demonstrate unprecedented selectivity, with up to 10 orders of magnitude higher stability for the manganese(II) than for the zinc(II) analogues, in sharp contrast to usual coordination chemistry rules.
Liposomes are nanocapsules widely used for the in vivo transport and delivery of therapeutic or diagnostic agents, or both. The therapeutic agent will only become active upon its release, thus sparing healthy tissues. The follow up of such release process is crucial to understand and control the drug action.
The previously reported approaches are based on optical imaging, using exclusively organic fluorophores or inorganic nanoparticles, co-encapsulated with the drug in the liposome.
The use of luminescent lanthanide complexes is an alternative which offers a number of advantages, including the capacity of those complexes to emit in the near infrared (NIR) region, enabling their detection in biological media.
The CBM research teams have developed an original nanocapsule : a liposome comprising an Ytterbium complex encapsulated with doxorubicin (anticancer agent). The NIR emission of the lanthanide complex is only observed when the drug is encapsulated. This NIR luminescence signal can therefore enable the direct follow-up, and in real time, of the integrity of the liposome, and can thus be used to detect the drug release.
An in vivo proof of concept was performed and the lanthanide luminescent signal could be detected in a mouse model of breast cancer.
Références de l'article :
Doxorubicin-sensitized Luminescence of NIR-emitting Ytterbium Liposomes: Towards Direct Monitoring of Drug Release,
Sara Lacerda, Anthony Delalande, Svetlana V. Eliseeva, Agnès Pallier, Célia S. Bonnet, Frédéric Szeremeta, Sandra Même, Chantal Pichon, Stéphane Petoud, Eva Toth
CBM scientists give answers in a publication published in the Journal Nature Communications. Why is Furanose the only sugar found in the composition of DNA and RNA while this form of sugar is not the most stable, so not the most abundant, in temperature conditions and pressure we are currently experiencing? These are the hydrothermal sources, omnipresent on the surface of the primitive land, and their complex thermal influence, which could be at the origin of this selectivity. This study conducted by scientists from the Molecular Biophysics Center, which is the subject of an article in the Nature Communications journal, should make it possible to better understand why and how molecules come together to give life in a primitive geological context.
Reference
Avinash Vicholous Dass, Thomas Georgelin, Frances Westall, Frédéric Foucher, Paolo De Los Rios, Daniel Maria Busiello, Shiling Liand & Francesco Piazza
Equilibrium and non-equilibrium furanose selection in the ribose isomerisation network Nature Communications, 12 2749 (2021) https://www.nature.com/articles/s41467-021-22818-5
The accumulation of aggregates of certain non-soluble peptides in tissues is characteristic of several pathologies, such as Alzheimer's and Parkinson's diseases, or diabetes. The detection of these amyloid deposits by in vivo imaging would be very useful for an early diagnostic and a better understanding of the molecular mechanisms of these diseases. Researchers from the Molecular Biophysics Center (CBM) and the Toulouse Coordination Chemistry Laboratory (LCC), in collaboration with Portuguese and Hungarian scientists, have taken an important step forward in the design of imaging agents that specifically recognize these amyloid deposits. This work is on the cover of Chemistry A European Journal.
