摘要
Construction of multifunctional/multimodality nanoparticles for cancer diagnosis and therapy has become an attractive area of investigation. In this report, we designed a multimodality nanoprobe for cell labeling, and can be detectable by both magnetic resonance and near infrared (NIR) fluorescence imaging. Multiple hydrophobic superparamagnetic iron oxide (SPIO) nanocrystals are self-assembled into nanocomposites in water phase with the help of partially alkylated hyperbranched polycation, polyethylenimine (PEI), which already conjugated with the indocyanine dye Cy5.5 and can be used for cell imaging under NIR fluorescence imaging. The amphiphilic PEI/SPIO nanocomposites have a strong T 2 relaxivity. The iron uptake process in MCF-7/Adr displays a time dependent behavior. Confocal laser scanning microscopy reveals that the nanoprobes are internalized into the cytoplasm of MCF-7/Adr after 24 h labeling. Both MR and NIR fluorescence imaging showed strong image contrast against unlabeled cells. Under a clinical MRI scanner, labeled cells in gelatin phantom present much darker images than controlled ones. The T2 relaxation rate of the labeled cells is 98.2 s 1 , significantly higher than that of the control ones of 2.3 s 1 . This study provides an important alternative to label MCF-7/Adr at optimized low dosages with high efficiency, and may be useful to label other biologically important cells and track their behaviors in vivo.
Construction of multifunctional/multimodality nanoparticles for cancer diagnosis and therapy has become an attractive area of investigation. In this report, we designed a multimodality nanoprobe for cell labeling, and can be detectable by both magnetic resonance and near infrared （NIR） fluorescence imaging. Multiple hydrophobic superparamagnetic iron oxide （SPIO） nanocrystals are self-assembled into nanocomposites in water phase with the help of partially alkylated hyperbranched polycation, polyethyl- enimine （PEI）, which already conjugated with the indocyanine dye Cy5.5 and can be used for cell imaging under NIR fluores- cence imaging. The amphiphilic PEI/SPIO nanocomposites have a strong T2 relaxivity. The iron uptake process in MCF-7/Adr displays a time dependent behavior. Confocal laser scanning microscopy reveals that the nanoprobes are internalized into the cy- toplasm of MCF-7/Adr after 24 h labeling. Both MR and NIR fluorescence imaging showed strong image contrast against unla- beled cells. Under a clinical MRI scanner, labeled cells in gelatin phantom present much darker images than controlled ones. The T2 relaxation rate of the labeled cells is 98.2 s-1, significantly higher than that of the control ones of 2.3 s-1. This study provides an important alternative to label MCF-7/Adr at optimized low dosages with high efficiency, and may be useful to label other biolog- ically important cells and track their behaviors in vivo.
基金
supported by the Program for New Century Excellent Talents in University (NCET-06-0781)
the Distinguished Young Scholars Project of Sichuan Province (06ZQ026-007)
the Doctoral Fund of Ministry of Education of China (20090181110068)
the National Natural Science Foundation of China (20974065, 51173117 and 50830107)
关键词
荧光成像
纳米粒子
聚阳离子
近红外
多模态
磁铁矿
两亲性
超顺磁性氧化铁
multifunctional, superparamagnetic iron oxide, multimodality, magnetic resonance imaging, near infrared fluorescenceimaging
