Detailseite
Projekt Druckansicht

Steigerung der MR-Sensitivität von 19F Biomarkern und PET-analogen 19F-markierten Rezeptorliganden durch Parawasserstoff-induzierte Polarisation

Fachliche Zuordnung Analytische Chemie
Medizinische Physik, Biomedizinische Technik
Förderung Förderung von 2014 bis 2017
Projektkennung Deutsche Forschungsgemeinschaft (DFG) - Projektnummer 257631981
 
Erstellungsjahr 2019

Zusammenfassung der Projektergebnisse

Within this project we developed an automated experimental setup, which allowed stable and reproducible hyperpolarization at different magnetic fields. This was a prerequisite for the detailed analysis of the complex reaction chain during the SABRE hyperpolarization of 19F. The systematic investigation of different aspects of 19F hyperpolarization using SABRE led to several new and previously unknown insights with regards to possible hyperpolarization transfer mechanisms from 1H to 19F. The position of fluorine plays an important role as on the 3-position (e.g. 3-fluoropyridine stronger hyperpolarization was observed than on the 2-position (e.g. 2-fluoropyridine). The pH value and the solvents had a strong influence on transfer mechanisms. In some cases an H/D-exchange was observed in methanol and this led to a hyperpolarization transfer to the OH-group of methanol but not to 19F. For further analysis new water-soluble catalysts were synthesized and characterized. The water solubility of other catalysts, such as the Ir-IMes catalyst, which were previously reported as watersoluble after activation, could not be confirmed. Similarly, a few of the water-soluble pyridine derivatives analyzed showed no hyperpolarization at either 1H or 19F. Thus, SABRE-based hyperpolarization of pyridine derivatives in solvents remains an important field of research but it seems that biocompatible application will require new approaches. As a consequence we investigated the potential of another promising hyperpolarization technique (photo-CIDNP) known to allow hyperpolarizing 19F-labeled biomolecules such as tyrosine and its derivatives in water using riboflavin as a photosensitizer. Both molecules play important roles in plant, animal and human metabolism. As preliminary work we modified the standard experimental approach by replacing the expensive, difficult to handle and potentially harmful Argon-laser by low cost blue-light LEDs. The achieved hyperpolarization was strong enough to acquire for the first time a 19F MR image of a photo-CIDNP hyperpolarized compound in aqueous solution using clinically applicable imaging sequences.

Projektbezogene Publikationen (Auswahl)

 
 

Zusatzinformationen

Textvergrößerung und Kontrastanpassung