Ahmad Tanveer, Bae Hongsub, Rhee Ilsu, Chang Yongmin, Jin Seong-Uk, Hong Sungwook
Department of Physics, Kyungpook National University, Daegu, 702-701, Korea.
J Nanosci Nanotechnol. 2012 Jul;12(7):5132-7. doi: 10.1166/jnn.2012.6368.
Gold-coated iron oxide (Fe3O4) nanoparticles were synthesized for use as a T2 contrast agent in magnetic resonance imaging (MRI). The coated nanoparticles were spherical in shape with an average diameter of 20 nm. The gold shell was about 2 nm thick. The bonding status of the gold on the nanoparticle surfaces was checked using a Fourier transform infrared spectrometer (FTIR). The FTIR spectra confirmed the attachment of homocysteine, in the form of thiolates, to the Au shell of the Au-Fe3O4 nanoparticles. The relaxivity ratio, R2/R1, for the coated nanoparticles was 3-fold higher than that of a commercial contrast agent, Resovist, which showed the potential for their use as a T2 contrast agent with high efficacy. In animal experiments, the presence of the nanoparticles in rat liver resulted in a 71% decrease in signal intensity in T2-weighted MR images, indicating that our gold-coated iron oxide nanoparticles are suitable for use as a T2 contrast agent in MRI.
合成了金包覆的四氧化三铁（Fe3O4）纳米颗粒，用作磁共振成像（MRI）中的T2造影剂。包覆的纳米颗粒呈球形，平均直径为20纳米。金壳厚度约为2纳米。使用傅里叶变换红外光谱仪（FTIR）检查纳米颗粒表面金的键合状态。FTIR光谱证实了以硫醇盐形式存在的同型半胱氨酸附着在Au-Fe3O4纳米颗粒的金壳上。包覆纳米颗粒的弛豫率R2/R1比商业造影剂Resovist高3倍，这表明它们有潜力用作高效的T2造影剂。在动物实验中，大鼠肝脏中纳米颗粒的存在导致T2加权MR图像中的信号强度降低了71%，这表明我们的金包覆四氧化三铁纳米颗粒适用于MRI中的T2造影剂。
