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Updated: Dec 24, 2025

Stable Aqueous Suspensions of Manganese Ferrite Clusters with Tunable Nanoscale Dimension and Composition
Published on: February 5, 2022
Carboxylic silane-exchanged manganese ferrite nanoclusters with high relaxivity for magnetic resonance imaging
Yingzhe Qi1, Chen Shao, Wei Gu
1School of Chemical Biology and Pharmaceutical Sciences, Capital Medical University, Beijing, P. R. China. lingye@ccmu.edu.cn.
Abstract:
To improve the magnetic properties and MRI contrast effect of Fe3O4 superparamagnetic nanoparticles (NPs), a series of oleate-capped, Mn-doped MnxFe(1-x)Fe2O4 (x≤ 0.4) NPs was prepared via a thermal decomposition method and subsequently assembled into nanoclusters by the carboxylic silane. The effects of Mn doping and clustering on the magnetization, relaxivity and contrast enhancement of the MnxFe(1-x)Fe2O4 (x≤ 0.4) NPs were studied. Our results revealed that the MnxFe(1-x)Fe2O4 NPs exhibited the highest saturation magnetization of 82.55 emu g-1 when x = 0.05. Correspondingly, the assembled Mn0.05Fe(1-0.05)Fe2O4 nanoclusters showed the highest relaxivity value of 528 (Mn + Fe) mM-1 s-1 and an enhanced MRI contrast in mouse liver. In addition, the MTT and H&E analysis confirmed that Mn0.05Fe(1-0.05)Fe2O4 nanoclusters were non-toxic. Therefore, the biocompatible Mn0.05Fe(1-0.05)Fe2O4 nanoclusters with superior relaxometric properties hold great potential in serving as a novel MRI nanoprobe.
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