Preparation method of nano Gd-MOFs for magnetic resonance imaging

Abstract

The invention discloses a preparation method of nano Gd-MOFs for magnetic resonance imaging. The preparation method of the nano Gd-MOFs comprises the following steps: (1) dissolving a metal salt, a ligand and a terminating agent in a solvent, and then mixing to obtain a mixed solution; (2) stirring the obtained mixed solution at room temperature, placing in a water bath, carrying out a stirring reaction, then placing in an oven, allowing to stand, centrifuging and washing, and dispersing and preserving by a solvent, to obtain oil-phase dispersed Gd-MOFs; (3) taking a certain amount of the Gd-MOFs obtained in the step (2), centrifuging to remove the solvent, modifying by an ethanol solution containing triethylamine, and finally, dispersing in water to obtain the nano Gd-MOFs for magnetic resonance imaging. Compared with the prior art, the preparation method is simple in preparation process and mild in reaction conditions. The prepared nano Gd-MOFs have the particle size of 45-60 nm, are near spherical, have uniform particle size distribution, and are more suitable for phagocytosis; in an ultra high field intensity of 11.7 T, the transverse relaxation rate r2 is measured to be 96.8 mM<-1>*s<-1>, and the magnetic relaxation rate is high; the disadvantage of high cytotoxicity of the nano Gd-MOFs is overcome; when the concentration of Gd is 0.4 mmol / L or less, the cell close packing T2 weighted imaging effect is obvious.

Description

technical field [0001] The invention belongs to the field of magnetic resonance imaging contrast agents, and in particular relates to a preparation method of nanometer Gd-MOFs for magnetic resonance imaging. Background technique [0002] Metal-organic frameworks (MOFs) are unique hybrid porous materials assembled from metal ions and organic groups. Compared with traditional porous materials, MOFs have multiple advantages, including large surface area, tunable pore size and shape, tunable composition and structure, biodegradability, and various functionalizations, which make MOFs promising for catalytic applications. , Selective adsorption separation and gas storage and other fields. Due to the tunability of MOFs, nanoscale metal-organic frameworks (nanoscale Metal-orannic frameworks, NMOFs) can be synthesized by rationally designing the structure and adjusting the synthesis conditions. Using paramagnetic metals such as gadolinium as metal ion connection points, NMOFs prepa...

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Problems solved by technology

It has been reported in the literature (J. Am. Chem. Soc, 2006, 128, 9024~9025) a method for synthesizing Gd-MOFs nanorods with good water dispersibility, the method is CTAB / n-hexanol / n-heptane / water The disadvantage of the reverse microemulsion synthesis method of the system is that the Gd-MOFs nanorods synthesized by this method are very toxic, which is not conducive to the use as an MRI contrast agent.

However, the existing nano-Gd-MOFs are often highly toxic, and their shapes are mostly rod-like or flake-like, which poses a major obstacle to their application in magnetic resonance imaging.

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