Doping engineering of iron oxide nanoparticles towards high performance and biocompatible T 1 ‐weighted MRI contrast agents

作者：Xue Xu, Pingli Dong, Yuyun Chai, Yang Run, Zhenhui Ma, Chichong Lu · 发表于：Rare Metals · 年份：2023 · DOI：10.1007/s12598-023-02443-5 · 被引用次数：17 · 研究领域：Iron oxide chemistry and applications、Nanoparticle-Based Drug Delivery、Characterization and Applications of Magnetic Nanoparticles

Abstract Extremely small‐sized iron oxide nanoparticles (IONPs) are of great interest in magnetic resonance imaging (MRI) due to their biosafety as an alternative to clinical gadolinium (III) complexes‐based contrast agents. Especially when the particle size is less than 10 nm, it has strong diffusion ability and deep penetration distance in tumor tissue. Substitution doping can significantly enhance the T 1 contrast effect of nanoparticles by regulating the surface exposed atoms. However, the nucleation and growth processes of multi‐component synthesis systems are complex and difficult to be accurately controlled, leading to great challenges in the synthesis of ultra‐small‐sized nanoparticles with different components and sizes. Here, extremely small‐sized superparamagnetic gadolinium‐doped iron oxide nanoparticles (GdIONPs, Gd x Fe 3− x O 4 NPs) with adjustable doping amount and controllable size in the range of 3.5–7.5 nm were synthesized by thermal decomposition. Then, as‐synthesized GdIONPs were surface modified with a highly water‐soluble and biocompatible carboxyl–polyethylene glycol–phosphoric acid ligand with high binding affinity. Gd 0.65 Fe 2.35 O 4 NPs exhibited very high r 1 relaxivity of 10.6 mmol –1 ·L·s –1 in terms of all metal concentrations and 49.0 mmol –1 ·L·s –1 in terms of gadolinium alone, respectively, 3 and 14 times higher than clinical T 1 contrast agents (Gd‐DTPA). GdIONPs can continuously obtain high resolution images of blood vessels, and can be u...