R3-Noria-methanesulfonate: A Molecular Cage with Superior Hyperpolarized Xenon-129 MRI Contrast

Area of Science:

• Molecular imaging
• Magnetic resonance imaging
• Supramolecular chemistry

Background:

• Hyperpolarized (HP) xenon-129 (129Xe) MRI is a promising molecular imaging technique.
• Development of effective contrast agents is crucial for advancing HP 129Xe MRI.
• Previous research focused on supramolecular cages for xenon MRI applications.

Purpose of the Study:

• To introduce and evaluate a novel macrocycle, resorcinarene trimer methanesulfonate (R3-Noria-MeSO3H), for HP 129Xe MRI.
• To investigate the contrast mechanisms offered by R3-Noria-MeSO3H in xenon MRI.
• To assess the performance of R3-Noria-MeSO3H at 3.0 T.

Main Methods:

• Synthesis and characterization of the resorcinarene trimer methanesulfonate (R3-Noria-MeSO3H).
• Acquisition of HP 129Xe MRI at 3.0 T to evaluate contrast.
• Implementation of hyperpolarized chemical exchange saturation transfer (HyperCEST) imaging.

Main Results:

• R3-Noria-MeSO3H demonstrated superior negative contrast in HP 129Xe MRI at 3.0 T.
• The macrocycle exhibited two distinct contrast mechanisms: increased spin-spin relaxation and HyperCEST.
• Successful HyperCEST imaging of the R3-Noria-MeSO3H macrocycle was achieved.

Conclusions:

• R3-Noria-MeSO3H is a unique macrocycle effective for xenon MRI.
• The dual contrast mechanisms enhance its utility for molecular imaging.
• Further studies on aggregation behavior and relaxivity of R3-Noria-methanesulfonate are warranted.