MRI detection of single particles for cellular imaging
MRI detection of single particles for cellular imaging
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DOI：
10.1073/pnas.0403918101
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发表时间：
2004-07-27
影响因子：
11.1
通讯作者：
Koretsky, AP
中科院分区：
文献类型：
--
作者：
Shapiro, EM;Skrtic, S;Koretsky, AP
MRI在分子和细胞成像中的应用迅速增长。这项工作的大部分依赖于纳米尺寸的超小葡聚糖涂层氧化铁颗粒的高弛豫率。通常，数百万个葡聚糖包被的超小氧化铁颗粒必须装载到细胞中以进行有效检测。在这里，我们表明，单一的，微米级的氧化铁颗粒（MPIOs）可以通过MRI检测在体外琼脂糖样品，培养的细胞，和小鼠胚胎。研究MRI分辨率和颗粒尺寸从0.76到1.63 μ m的影响的实验表明，T-2（*）效应可以很容易地检测到从单个MPIO在50 μ m的分辨率和显着的信号效应可以检测到在分辨率低至200 μ m。用荧光MPIO标记培养的细胞，使得单个颗粒存在于单个细胞中。单细胞中的这些单颗粒可以通过MRI和荧光显微镜检测到。最后，注射到单细胞阶段小鼠胚胎中的单个颗粒可以在胚胎第11.5天检测到，这表明即使经过多次细胞分裂，子细胞仍然携带单个颗粒。这些结果表明，MRI可以检测单个粒子，并表明单粒子检测将是有用的细胞成像。
There is rapid growth in the use of MRI for molecular and cellular imaging. Much of this work relies on the high relaxivity of nanometer-sized, ultrasmall dextran-coated iron oxide particles. Typically, millions of dextran-coated ultrasmall iron oxide particles must be loaded into cells for efficient detection. Here we show that single, micrometer-sized iron oxide particles (MPIOs) can be detected by MRI in vitro in agarose samples, in cultured cells, and in mouse embryos. Experiments studying effects of MRI resolution and particle size from 0.76 to 1.63 mum indicated that T-2(*) effects can be readily detected from single MPIOs at 50-mum resolution and significant signal effects could be detected at resolutions as low as 200 mum. Cultured cells were labeled with fluorescent MPIOs such that single particles were present in individual cells. These single particles in single cells could be detected both by MRI and fluorescence microscopy. Finally, single particles injected into single-cell-stage mouse embryos could be detected at embryonic day 11.5, demonstrating that even after many cell divisions, daughter cells still carry individual particles. These results demonstrate that MRI can detect single particles and indicate that single-particle detection will be useful for cellular imaging.