Typologie d'actualités: Team Chemistry, Imaging and Exobiology

A CBM team has developed a contrast agent capable of revealing oxidative stress in living tissue

The "Metal Complexes and MRI" team, in collaboration with a Hungarian team, has developed a contrast agent based on an iron compound associated with a fluorinated ligand. This makes it possible to map oxidative stress in living tissue, a marker of numerous pathologies. This molecular detector, still at the pre-clinical stage, could considerably enrich tomorrow's medical imaging toolkit.

This major advance has been published in the journal JACS.
Relaxation-Based In Vivo Discrimination of Oxidized and Reduced States of a Redox-Switchable 19F MRI Probe
Garda Z., Szeremeta F., Tóth C.S., Bunda S., Pifferi C., Clémençon R., Même S., Tircso G., Tóth É.
J. Am. Chem. Soc. 2025, 147, 21, 18017-18024

Find out more on the CNRS Chimie website.

 

Martina Sanadar, PhD in Environmental and Energy Engineering, is a post-doctoral fellow at CBM

Originally from Italy, Martina Sanadar has a PhD in environmental and energy engineering. She has been a post-doctoral fellow in the "Metal Complexes and MRI" team for the past year. Her research focuses on the development of bioinspired MRI contrast agents sensitive to Cu²⁺. In vivo imaging of extracellular Cu²⁺ is of great interest due to its biological importance in physiological and pathological states. However, the development of effective and selective MRI contrast agents for Cu²⁺, especially compared to the more abundant Zn²⁺ ions, remains a considerable challenge.

Martina Sanadar contributes her expertise in coordination and physical chemistry, solution thermodynamics and various techniques (potentiometry, relaxivity measurements, luminescence spectroscopy, UV-visible spectroscopy and calorimetry).

She joined the CBM for the excellence of its research, its collaborative environment and advanced equipment, as well as the opportunity to work in France. The CBM's interdisciplinary approach and international collaborations align perfectly with her professional goals, making it an ideal destination to further her career.

CBM doctoral student wins prize for best oral presentation at symposium

Petra Cutuk, doctorante au CBM, a reçu le prix de la meilleure présentation orale lors du colloque 2025 du Réseau Molécules Marines, Métabolisme et Cancer.

Petra Cutuk, doctorante de deuxième année, qui effectue son travail de recherche conjointement entre l'équipe "Composés luminescents de lanthanides, spectroscopie et bioimagerie optique" du CBM d'Orléans et l'équipe Inserm "U1069 - Niche, Nutrition, Cancer & métabolisme Oxydatif- N2Cox" de l'Université de Tours, a reçu le prix de la meilleure présentation orale pour sa présentation intitulée "Elucidating the Regulation of SKCa Channels by the cAMP/PKA Pathway in Cancer Cells: Innovations in Near-Infrared Optical Imaging Agents" lors du colloque annuel 2025 du Réseau Molécules Marines, Métabolisme & Cancer à Mansigné le 16 mai 2025.

The prize is awarded by the Fondation ARC pour la recherche sur le cancer to finance participation in a conference.

Petra Cutuk is on the right in the photo.

 

Combination of nanomedicine and biophysics methods to characterize mRNA liposomes

This new optimised version of liposomes has been reported by CNRS Chimie on its website.

The development of lipid-based mRNA delivery systems has significantly advanced mRNA-based therapies. Liposomes, in particular histidylated liposomes (LYX), have been shown to be effective in delivering nucleic acids. In this study, LYX liposomes were optimised by adding a freeze-drying and extrusion step, resulting in improved homogeneity and storage stability. LYX liposomes maintained their size (150 ± 10 nm) and polydispersity index (0.10 ± 0.02) for up to a year at 4°C, while preserving their transfection efficiency. They exhibit a high mRNA encapsulation rate (∼95%) and protect it from degradation by RNases. The lamellar organisation was confirmed by small-angle X-ray scattering and CryoTEM. These liposomes allow efficient transfection of cell lines and primary cells, albeit with lower efficiency than commercial vectors, due to slower cell internalisation and reduced endosomal escape. They have demonstrated their ability to deliver mRNA encoding the therapeutic molecules BMP2 and BMP9, leading to the production of functional proteins capable of inducing BMP signalling. In vivo studies have also confirmed their potential for mRNA delivery when incorporated into hydrogels and implanted subcutaneously in mice. These results show that LYX liposomes are a promising and versatile platform for mRNA delivery in therapeutic applications.

This work involved laboratories from two institutes: the Centre de Biophysique Moléculaire (CNRS Chimie) and the Laboratoire de Biologie, Bioingénierie et Bioimagerie Ostéo-Articulaires (CNRS Ingénierie).

Reference:
Albert Ngalle Loth, Manon Maroquenne, Ayoub Medjmedj, Franck Coste, Thomas Bizien, Chantal Pichon, Delphine Logeart-Avramoglou, Federico Perche.
Structural and functional characterization of a histidylated liposome for mRNA deliveryStructural and functional characterization of a histidylated liposome for mRNA delivery.
Journal of Controlled Release (2025) Volume 379, pages 164-176, doi: 10.1016/j.jconrel.2025.01.010.

‘Etonnante Chimie’ (Amazing Chemistry): a CBM chemistry team welcomed secondary school students from Tours

Following the publication of the book “ Etonnante Chimie ” and as part of the project “ Etonnante chimie pour un grand oral percutant ” (“Amazing Chemistry for a Successful Oral Exam”), the “Metal complexes and MRI” team, led by Dr Eva Jakab Toth and Célia Bonnet, has been welcoming, for 4 consecutive years, first-year high school students from the Vaucanson high school in Tours.