Preparation method and application of single-atom gadolinium contrast agent supported on hollow nitrogen-doped carbon spheres

Abstract

The invention provides a preparation method and application of a single-atom gadolinium contrast agent supported by hollow nitrogen-doped carbon spheres. The method prepares size-controllable nano-silica microspheres as a template, simultaneously coats dopamine and gadolinium ions on the surface of nano-silica microspheres, and obtains nitrogen-doped carbon-supported single-atom gadolinium through high-temperature calcination; then The silicon dioxide is etched away, and the surface is coated with a hydrophilic polymer to obtain a PEGylated hollow nitrogen-doped carbon sphere loaded monoatomic gadolinium contrast agent. Through the above method, the unique Gd-N-C structure of the present invention can make the monoatomic gadolinium anchored stably by the nitrogen atom without falling off, which improves the biological safety, and the polyethylene glycol coated on the surface further improves its water solubility and biocompatibility; the single-atom contrast agent can make full use of each gadolinium atom, which improves the utilization rate of metal atoms; it has excellent contrast imaging ability and effect, and is a new type of contrast agent with wide application and good prospects.

Description

technical field [0001] The invention relates to the technical field of contrast agent preparation, in particular to a preparation method and application of a single-atom gadolinium contrast agent supported on hollow nitrogen-doped carbon spheres. Background technique [0002] Magnetic resonance imaging is a non-invasive disease diagnosis method widely used in clinical practice. It has the advantages of high spatial resolution, good deep tissue and soft tissue imaging effect, safety and high efficiency. In order to further improve the contrast and sensitivity of MRI, gadolinium-based MRI contrast agents are widely used to enhance T 1 MRI effects. Gadolinium element has seven unpaired electrons arranged in the same direction, which can effectively reduce the relaxation time of water protons in the detected tissue, and has a significant enhancement performance of nuclear magnetic resonance imaging. More than one-third of MRI scans use commercially available gadolinium metal c...

AI Technical Summary

Problems solved by technology

However, commercially available gadolinium metal chelates are small molecules with fast metabolism and short retention time in the body. Due to their distribution throughout the body, they have no targeting and weak tumor accumulation.

Commercial gadolinium metal chelates are unstable in acidic environments, and there is a risk of gadolinium ion shedding, and free gadolinium ions can cause renal fibrosis, which limits the application and application of gadolinium chelate contrast agents in MRI-enhanced imaging. biosecurity

[0003] The development of gadolinium-based nanomaterials provides an idea to solve the problems of small-molecule gadolinium metal chelates. However, synthetic gadolinium-based nanomaterial contrast agents with good biocompatibility, strong contrast enhancement effect and tumor targeting are still a challenge. big challenge

At the same time, because the gadolinium atoms inside the nanomaterials cannot fully contact with water molecules, they cannot fully exert their enhancement effect on the relaxation efficiency of water protons.

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