Cell internalization of anionic maghemite nanoparticles: Quantitative effect on magnetic resonance imaging
Cell internalization of anionic maghemite nanoparticles: Quantitative effect on magnetic resonance imaging
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DOI：
10.1002/mrm.10418
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发表时间：
2003-04-01
影响因子：
3.3
通讯作者：
Gazeau, F
中科院分区：
文献类型：
--
作者：
Billotey, C;Wilhelm, C;Gazeau, F
阴离子氧化铁纳米颗粒被有效地内化到巨噬细胞中，在巨噬细胞中它们集中在微米内体中，赋予它们高的磁化率。通过电子自旋共振（ESR）实验定量巨噬细胞对阴离子磁赤铁矿纳米颗粒的摄取。采用不同的TE和TR进行MR自旋回波序列。对比度增强之间的两种类型的琼脂糖phantomy具有相同的等效铁氧体浓度，但含有分散的孤立的纳米粒子或磁性标记的巨噬细胞进行了比较。结果表明，磁赤铁矿纳米粒子的细胞内限制在微米内体的结果在一个显着的纵向弛豫率和横向弛豫率的适度降低相比，分散的孤立的纳米粒子的弛豫率的降低。因此，内体磁标记的签名由在整个铁氧体浓度范围内的T-1加权图像上的负对比度组成，而细胞外分离的纳米颗粒的存在可以导致正增强。(C)2003 Wiley-Liss，Inc.
Anionic iron oxide nanoparticles are efficiently internalized into macrophages where they concentrate within micrometric endosomes, conferring on them a high magnetic susceptibility. The uptake of anionic maghemite nanoparticles by macrophages was quantified by an electron spin resonance (ESR) experiment. MR spin-echo sequences were performed with various TEs and TRs. The contrast enhancement was compared between two types of agarose phantoms with the same equivalent ferrite concentrations but containing either dispersed isolated nanoparticles or magnetically labeled macrophages. It is shown that the intracellular confinement of maghemite nanoparticles within micrometric endosomes results in a significant decrease of the longitudinal relaxivity and a moderate decrease of the transverse relaxivity compared to the relaxivities of the dispersed isolated nanoparticles. As a consequence, the signature of endosomal magnetic labeling consists of a negative contrast on T-1-weighted images in the whole ferrite concentration range, whereas the presence of extracellular isolated nanoparticles can result in a positive enhancement. (C) 2003 Wiley-Liss, Inc.