Engineered iron-oxide-based nanoparticles as enhanced T1 contrast agents for efficient tumor imaging.

Abstract

We report the design and synthesis of small-sized zwitterion-coated gadolinium-embedded iron oxide (GdIO) nanoparticles, which exhibit a strong T1 contrast effect for tumor imaging through enhanced permeation and retention effect and the ability to clear out of the body in living subjects. The combination of spin-canting effects and the collection of gadolinium species within small-sized GdIO nanoparticles led to a significantly enhanced T1 contrast effect. For example, GdIO nanoparticles with a diameter of ∼4.8 nm exhibited a high r1 relaxivity of 7.85 mM(-1)·S(-1) and a low r2/r1 ratio of 5.24. After being coated with zwitterionic dopamine sulfonate molecules, the 4.8 nm GdIO nanoparticles showed a steady hydrodynamic diameter (∼5.2 nm) in both PBS buffer and fetal bovine serum solution, indicating a low nonspecific protein absorption. This study provides a valuable strategy for the design of highly sensitive iron-oxide-based T1 contrast agents with relatively long circulation half-lives (∼50 min), efficient tumor passive targeting (SKOV3, human ovarian cancer xenograft tumor as a model), and the possibility of rapid renal clearance after tumor imaging.

• Authors: Zijian Zhou, Lirong Wang, Xiaoqin Chi, Jianfeng Bao, Lijiao Yang, Wenxiu Zhao, Zhong Chen, Xiaomin Wang, Xiaoyuan Chen, Jinhao Gao
• Journal: ACS nano (ACS Nano) Vol. 7 Issue 4 Pg. 3287-96 (Apr 23 2013) ISSN: 1936-086X [Electronic] United States
• PMID: 23473444 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Contrast Media
• Magnetite Nanoparticles
• Nanocapsules
• Gadolinium

Topics

• Animals
• Cell Line, Tumor
• Contrast Media (chemical synthesis)
• Female
• Gadolinium (chemistry)
• Humans
• Magnetic Resonance Imaging (methods)
• Magnetite Nanoparticles (chemistry)
• Mice
• Nanocapsules (chemistry)
• Ovarian Neoplasms (pathology)
• Reproducibility of Results
• Sensitivity and Specificity