Synthesis and Evaluation of a potential pH-Responsive MRI probe based on Mn(II) chelated with 3,9-PC2Py-Hm

Abstract

The onset of nephrogenic systemic fibrosis (NSF) in patients with severe renal failure disputed the dominance of gadolinium-based MRI contrast agents. This prompted research to maneuver towards safer and biocompatible alternatives, with manganese emerging as a prominent candidate. In this study, a suitable Mn(II) chelator based on a pyclen derivative appended with pyridin-(2-yl)methanol pendant arms was succesfully synthesized. Their complexes formed with Mn(II) possessed a considerable thermodynamic stability and kinetic inertness, in comparison to the relative benchmarks. The complex also exhibited pH-sensitivity at a higher pH range. To summarize, the Mn(II) complex formed with the 3,9-PC2Py-Hm ligand chelation is a prospective pH-sensitive MRI probe.