Issue 28, 2025

Macrocyclic transition-metal parashift complexes for MRI at clinical and pre-clinical magnetic fields

Abstract

A series of macrocyclic transition-metal complexes, including Fe(II), Co(II), Ni(II), and Cu(II) complexes, have been evaluated for parashift MRI imaging applications, by assessing their paramagnetic NMR properties, including proton chemical shifts, nuclear relaxation rates, and any exchange dynamics in solution, at magnetic fields strengths relevant to clinical and pre-clinical imaging. Among the complexes studied, Fe(II) and Co(II) systems demonstrated significant paramagnetic shifts with desirable relaxation properties, making them potential candidates for lanthanide-free parashift molecular probes for MRI. Field-dependent nuclear relaxation rate analyses provided insights into electronic relaxation times, confirming the suitability of certain complexes for parashift imaging at lower magnetic fields. Phantom imaging experiments at 9.4 T further validated the feasibility of molecular imaging using a cyclen-based macrocyclic Fe(II) complex, making a significant advance toward developing transition metal-based MRI probes using biogenic metal ions, and offer promise for future responsive imaging due to the direct signal detection.

Graphical abstract: Macrocyclic transition-metal parashift complexes for MRI at clinical and pre-clinical magnetic fields

Supplementary files

Transparent peer review

To support increased transparency, we offer authors the option to publish the peer review history alongside their article.

View this article’s peer review history

Article information

Article type
Paper
Submitted
15 May 2025
Accepted
24 Jun 2025
First published
25 Jun 2025
This article is Open Access
Creative Commons BY license

Dalton Trans., 2025,54, 11036-11046

Macrocyclic transition-metal parashift complexes for MRI at clinical and pre-clinical magnetic fields

N. J. Rogers, C. Ashok Kumar, C. Alexander, D. Bowdery, G. Pavlovskaya and P. Harvey, Dalton Trans., 2025, 54, 11036 DOI: 10.1039/D5DT01149C

This article is licensed under a Creative Commons Attribution 3.0 Unported Licence. You can use material from this article in other publications without requesting further permissions from the RSC, provided that the correct acknowledgement is given.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements