Gated Luminescence Imaging of Silicon Nanoparticles.
Gated Luminescence Imaging of Silicon Nanoparticles.
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DOI：
10.1021/acsnano.5b01594
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发表时间：
2015-06-23
期刊：
影响因子：
17.1
通讯作者：
Sailor MJ
中科院分区：
文献类型：
--
作者：
Joo J;Liu X;Kotamraju VR;Ruoslahti E;Nam Y;Sailor MJ
纳米晶硅的发光寿命通常为微秒量级，显著长于细胞和组织中天然存在的荧光分子所表现出的纳秒寿命。时间选通成像（其中在激发脉冲终止之后的时间获取图像）允许从这些内源性信号中区分硅纳米颗粒探针。由于硅发射的微秒时间尺度，对于这种生物相容性和无毒探针，时间门控成像相对简单。在这里，时间选通系统与~10 ns的分辨率进行了描述，使用增强CCD相机和脉冲LED或激光激发源。该方法通过跟踪含有肿瘤靶向肽iRGD的介孔硅纳米颗粒的命运来证明，所述介孔硅纳米颗粒通过眶后注射给药到活小鼠中。这种全身施用的纳米颗粒在体内的成像是特别具有挑战性的，因为在靶组织中探针的浓度低，并且来自组织自体荧光的背景信号相对高。在靶组织中证实了>100倍的对比度改善（相对于稳态成像）。
The luminescence lifetime of nanocrystalline silicon is typically on the order of microseconds, significantly longer than the nanosecond lifetimes exhibited by fluorescent molecules naturally present in cells and tissues. Time-gated imaging, where the image is acquired at a time after termination of an excitation pulse, allows discrimination of a silicon nanoparticle probe from these endogenous signals. Because of the microsecond time scale for silicon emission, time-gated imaging is relatively simple to implement for this biocompatible and nontoxic probe. Here a time-gated system with ~10 ns resolution is described, using an intensified CCD camera and pulsed LED or laser excitation sources. The method is demonstrated by tracking the fate of mesoporous silicon nanoparticles containing the tumor-targeting peptide iRGD, administered by retro-orbital injection into live mice. Imaging of such systemically administered nanoparticles in vivo is particularly challenging because of the low concentration of probe in the targeted tissues and relatively high background signals from tissue autofluorescence. Contrast improvements of >100-fold (relative to steady-state imaging) is demonstrated in the targeted tissues.