Paramagnetic Ultrasmall Gadolinium Oxide Nanoparticles as Advanced T1 MRI Contrast Agent: Account for Large Longitudinal Relaxivity, Optimal Particle Diameter, and In Vivo T1 MR Images

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• 作者：Ja Young Park ; Myung Ju Baek ; Eun Sook Choi ; Seungtae Woo ; Joo Hyun Kim ; Tae Jeong Kim ; Jae Chang Jung ; Kwon Seok Chae ; Yongmin Chang ; Gang Ho Lee
• 刊名：ACS Nano
• 出版年：2009
• 出版时间：November 24, 2009
• 年：2009
• 卷：3
• 期：11
• 页码：3663-3669
• 全文大小：416K
• 年卷期：0
• ISSN：1936-086X

文摘

Paramagnetic ultrasmall gadolinium oxide (Gd₂O₃) nanoparticles with particle diameters (d) of ∼1 nm were synthesized by using three kinds of Gd(III) ion precursors and by refluxing each of them in tripropylene glycol under an O₂ flow. A large longitudinal relaxivity (r₁) of water proton of 9.9 s⁻¹ mM⁻¹ was estimated. As a result, high contrast in vivo T₁ MR images of the brain tumor of a rat were observed. This large r₁ is discussed in terms of the huge surface to volume ratio (S/V) of the ultrasmall gadolinium oxide nanoparticles coupled with the cooperative induction of surface Gd(III) ions for the longitudinal relaxation of a water proton. It is found from the d dependence of r₁ that the optimal range of d for the maximal r₁, which may be used as an advanced T₁ MRI contrast agent, is 1−2.5 nm.