Engineered Iron-Oxide-Based Nanoparticles as Enhanced T1 Contrast Agents for Efficient Tumor Imaging

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• 作者：Zijian Zhou ; Lirong Wang ; Xiaoqin Chi ; Jianfeng Bao ; Lijiao Yang ; Wenxiu Zhao ; Zhong Chen ; Xiaomin Wang ; Xiaoyuan Chen ; Jinhao Gao
• 刊名：ACS Nano
• 出版年：2013
• 出版时间：April 23, 2013
• 年：2013
• 卷：7
• 期：4
• 页码：3287-3296
• 全文大小：673K
• 年卷期：v.7,no.4(April 23, 2013)
• ISSN：1936-086X

文摘

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^鈥?路S^鈥? 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.

Keywords:

T₁ contrast agent; ultrasmall nanoparticle; zwitterionic; renal clearance; tumor imaging