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Published on: July 20, 2022
Ligand-Induced Atomically Segregation-Tunable Alloy Nanoprobes for Enhanced Magnetic Resonance Imaging
Zeyu Liang1, Shangzhi Xie2, Qiyue Wang1
1Frontiers Science Center for Transformative Molecules, School of Chemistry and Chemical Engineering, National Center for Translational Medicine, State Key Laboratory of Oncogenes and Related Genes, Shanghai Jiao Tong University, Shanghai 200240, China.
Ligand-induced tunable alloy nanoprobes (STAN) enhance iron-gold nanoparticle performance for magnetic resonance imaging (MRI). Optimized STAN shows superior relaxivity, enabling sensitive detection of small hepatic tumors in vivo.
Area of Science:
- Nanotechnology
- Materials Science
- Biomedical Imaging
Background:
- Bimetallic iron-noble metal alloy nanoparticles are promising MRI contrast agents.
- Surface energy differences can cause iron segregation, limiting relaxometric performance.
- Controlling element distribution is key to enhancing MRI contrast agents.
Purpose of the Study:
- To develop tunable alloy nanoprobes (STAN) for improved MRI contrast.
- To overcome Fe atom segregation in bimetallic nanoparticles.
- To enhance relaxometric performance for sensitive tumor detection.
Main Methods:
- Synthesized bimetallic iron-gold nanoparticles with tunable surface Fe content.
- Manipulated Fe oxidation state and surface enrichment using ligand molar ratios (oleic acid/oleylamine).
- Evaluated relaxometric properties (r1, r2/r1) and in vivo tumor imaging performance at 9 T MRI.
Main Results:
- Achieved surface Fe enrichment up to 60.1 at % through ligand manipulation.
- Optimized STAN demonstrated an r1 value of 2.28 mM-1·s-1 and an r2/r1 ratio of 6.2.
- Successfully visualized 0.7 mm hepatic tumors in vivo with high sensitivity.
Conclusions:
- Ligand-induced atomic segregation tuning is effective for enhancing nanoparticle MRI contrast agents.
- STAN nanoprobes offer superior relaxometric performance compared to conventional agents.
- STAN represents a promising next-generation contrast agent for highly sensitive MR imaging.
