Poly 尾-Cyclodextrin/TPdye Nanomicelle-based Two-Photon Nanoprobe for Caspase-3 Activation Imaging in Live Cells and Tissues

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• 作者：Huijuan Yan ; Leiliang He ; Wenjie Zhao ; Jishan Li ; Yue Xiao ; Ronghua Yang ; Weihong Tan
• 刊名：Analytical Chemistry
• 出版年：2014
• 出版时间：November 18, 2014
• 年：2014
• 卷：86
• 期：22
• 页码：11440-11450
• 全文大小：572K
• ISSN：1520-6882

文摘

Two-photon excitation (TPE) with near-infrared (NIR) photons as the excitation source has important advantages over conventional one-photon excitation (OPE) in the field of biomedical imaging. 尾-cyclodextrin polymer (尾CDP)-based two-photon absorption (TPA) fluorescent nanomicelle exhibits desirable two-photon-sensitized fluorescence properties, high photostability, high cell-permeability and excellent biocompatibility. By combination of the nanostructured two-photon dye (TPdye)/尾CDP nanomicelle with the TPE technique, herein we have designed a TPdye/尾CDP nanomicelle-based TPA fluorescent nanoconjugate for enzymatic activity assay in biological fluids, live cells and tissues. This sensing system is composed of a trans-4-[p-(N,N-diethylamino)styryl]-N-methylpyridinium iodide (DEASPI)/尾CDP nanomicelle as TPA fluorophore and carrier vehicle for delivery of a specific peptide sequence to live cell through fast endocytosis, and an adamantine (Ad)-GRRRDEVDK-BHQ2 (black hole quencher 2) peptide (denoted as Ad-DEVD-BHQ2) anchored on the DEASPI/尾CDP nanomicelle鈥檚 surface to form TPA DEASPI/尾CDP@Ad-DEVD-BHQ2 nanoconjugate by the 尾CD/Ad host鈥揼uest inclusion strategy. Successful in vitro and in vivo enzymatic activities assay of caspase-3 was demonstrated with this sensing strategy. Our results reveal that this DEASPI/尾CDP@Ad-DEVD-BHQ2 nanoconjugate not only is a robust, sensitive and selective sensor for quantitative assay of caspase-3 in the complex biological environment but also can be efficiently delivered into live cells as well as tissues and act as a 鈥渟ignal-on鈥?fluorescent biosensor for specific, high-contrast imaging of enzymatic activities. This DEASPI/尾CDP@Ad-DEVD-BHQ2 nanoconjugate provides a new opportunity to screen enzyme inhibitors and evaluate the apoptosis-associated disease progression. Moreover, our design also provides a methodology model scheme for development of future TPdye/尾CDP nanomicelle-based two-photon fluorescent probes for in vitro or in vivo determination of biological or biologically relevant species.