Zwitterionic Manganese and Gadolinium Metal–Organic Frameworks as Efficient Contrast Agents for in Vivo Magnetic Resonance Imaging

Abstract

Two water-stable three-dimensional Mn- and Gd-based metal-organic frameworks (MOFs), {[Mn(Cmdcp)(HO)]·HO} (1) and {[Gd(Cmdcp)(HO)](NO)·3HO} (2, HCmdcpBr = N-(4-carboxy benzyl)-(3,5-dicarboxyl)pyridinium bromide), have been prepared and analyzed. In vitro magnetic resonance imaging indicated that MOFs 1 and 2 possess relaxivity r values of 17.50 and 13.46 mM·S, respectively, which are superior to that of the control Gd-DTPA (r = 4.87 mM·S, DTPA = diethylene triamine pentaacetate). MOFs 1 and 2 also possessed good biocompatibility and low cytotoxicity against a model cell line. In vivo magnetic resonance images of treated Kunming mice indicated that kidneys showed remarkably positive signal enhancement after 15 min with intravenous administration of MOF 1 and the hyperintensity of both kidneys persisted for about 240 min with no obvious tissue damage. MOF 1 is therefore promising in vivo probes for imaging intravascular diseases and renal dysfunction.

Metal-Organic Frameworks for Bioimaging: Strategies and Challenges

“…Besides, Qin et al [80] designed and synthesized two water-stable 3D Mn-based MOF (1) and Gd-based MOF (2) as high-efficiency contrast agents for MRI. Furthermore, in vitro MRI demonstrated that the relaxation r1 of 1 and 2 was 17.50 mM -1 •S -1 and 13.46 mM -1 •S -1 , respectively, which are higher than the r 1 (4.87 mM -1 •S -1 ) of similar Gd-DTPA (DTPA = diethylenetriamine pentaacetate).…”

Applications of nanoscale metal–organic frameworks as imaging agents in biology and medicine

“…121,139 2), and showed their applications as strong MRI contrast agents under in vivo conditions. 142 The in vitro characterization by MRI demonstrated that Mn-based MOF possessed a slightly higher relaxivity r1 value (17.50 mM -1 •S -1 ) compared with the Gd-based analogue (13.46 mM -1 •S -1 ), and both of them are superior to that of the clinical positive contrast agent, Gd-DTPA (DTPA = diethylene triamine pentaacetate, r1 = 4.87 mM -1 •S -1 ) used as a control in the study (Figs. 13a and 13b).…”

Designing Magnetic NanoMOFs for Biomedicine: Current Trends and Applications

“…The choice of the ligand is strictly related to increasing the nanoMOF solubility and stability in aqueous environments, while the choice of the MOF network is made with the aim of lowering the Mn II toxicity by encapsulating the metal in the nanoparticles. Due to the presence of Mn II , the MOF shows good R1 relaxivities and T1-weighted images, making this nanoMOF particularly useful as an MRI contrast agent for revealing kidney-related pathologies [81].…”