Activatable Fluorescence/MRI Bimodal Platform for Tumor Cell Imaging via MnO2 Nanosheet鈥揂ptamer Nanoprobe

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• 作者：Zilong Zhao ; Huanhuan Fan ; Gaofeng Zhou ; Huarong Bai ; Hao Liang ; Ruowen Wang ; Xiaobing Zhang ; Weihong Tan
• 刊名：Journal of the American Chemical Society
• 出版年：2014
• 出版时间：August 13, 2014
• 年：2014
• 卷：136
• 期：32
• 页码：11220-11223
• 全文大小：262K
• ISSN：1520-5126

文摘

A novel dual-activatable fluorescence/MRI bimodal platform is designed for tumor cell imaging by using a redoxable manganese dioxide (MnO₂) nanosheet鈥揳ptamer nanoprobe. The redoxable MnO₂ nanosheet acts as a DNA nanocarrier, fluorescence quencher, and intracellular glutathione (GSH)-activated MRI contrast agent. In the absence of target cells, neither fluorescence signaling nor MRI contrast of the nanoprobe is activated. In the presence of target cells, the binding of aptamers to their targets weakens the adsorption of aptamers on the MnO₂ nanosheets, causing partial fluorescence recovery, illuminating the target cells, and also facilitating the endocytosis of nanoprobes into target cells. After endocytosis, the reduction of MnO₂ nanosheets by GSH further activates the fluorescence signals and generates large amounts of Mn²⁺ ions suitable for MRI. This platform should facilitate the development of various dual-activatable fluorescence/MRI bimodalities for use in cells or in vivo.