Gd-Dots with Strong Ligand−Water Interaction for Ultrasensitive Magnetic Resonance Renography Xiao-Yu Zheng,† Kai Zhao,‡ Jinglong Tang,§ Xin-Yu Wang,† Lin-Dong Li,† Nai-Xiu Chen,† Yan-Jie Wang,† Shuo Shi,† Xiaodong Zhang,‡ Sivakumar Malaisamy,† Ling-Dong Sun,*,† Xiaoying Wang,*,‡ Chunying Chen,§ and Chun-Hua Yan*,† †
Beijing National Laboratory for Molecular Sciences, State Key Laboratory of Rare Earth Materials Chemistry and Applications, PKU-HKU Joint Laboratory in Rare Earth Materials and Bioinorganic Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China ‡ Department of Radiology, Peking University First Hospital, Beijing 100034, China § CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety and CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology of China, Beijing 100190, China S Supporting Information *
ABSTRACT: Magnetic resonance imaging contrast agents with both significantly enhanced relaxivity and minimal safety risk are of great importance for sensitive clinical diagnosis, but have rarely been reported. Herein, we present a simple strategy to improve relaxivity by introducing surface ligands with strong interaction to water molecules. As a proof of concept, NaGdF4 nanoparticles (NPs) capped by poly(acrylic acid) (PAA) show superior relaxivity to those capped by polyethylenimine and polyethylene glycol, which is attributed to the strong hydrogen-bond capacity of PAA to water molecules as revealed by theoretical calculation. Furthermore, benefiting from PAA and ultrasmall particle size, Gd-dots, namely PAA-capped GdOF NPs (2.1 ± 0.2 nm), are developed as a high-performance contrast agent, with a remarkable ionic relaxivity of ∼75 mM−1 s−1 in albumin solution at 0.5 T. These Gd-dots also exhibit efficient renal clearance with
