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《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(41):12655-12659
Antibodies are important biopharmaceuticals, but almost all existing antibody‐based drugs are limited to targeting antigens located at the cell exterior because of the inability of antibodies to enter the cell interior. Available methods for intracellular delivery of antibodies have major shortcomings. Herein, we report an approach to encapsulate native antibodies in a biodegradable silica nanoquencher (BS‐qNP), which could undergo efficient cellular uptake and intracellular degradation to release antibodies only under hypoxic conditions. By coating the surface of BS‐qNP with cell‐penetrating poly(disulfide)s (CPD), the delivered antibodies (or other proteins) avoided endolysosomal trapping. Doping of the silica coating with a fluorescent dye and a dark hole quencher further endowed BS‐qNP with hypoxia‐responsive fluorescence turn‐on property. Our antibody delivery system thus provides the first platform capable of stable encapsulation, efficient uptake, on‐demand antibody release, and imaging of release/cell state. 相似文献
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Liulin Wang Wei Du Zhangjun Hu Kajsa Uvdal Lin Li Wei Huang 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(40):14164-14181
Fluorophores and probes are invaluable for the visualization of the location and dynamics of gene expression, protein expression, and molecular interactions in complex living systems. Rhodamine dyes are often used as scaffolds in biological labeling and turn‐on fluorescence imaging. To date, their absorption and emission spectra have been expanded to cover the entire near‐infrared region (650–950 nm), which provides a more suitable optical window for monitoring biomolecular production, trafficking, and localization in real time. This review summarizes the development of rhodamine fluorophores since their discovery and provides strategies for modulating their absorption and emission spectra to generate specific bathochromic‐shifts. We also explain how larger Stokes shifts and dual‐emissions can be obtained from hybrid rhodamine dyes. These hybrid fluorophores can be classified into various categories based on structural features including the alkylation of amidogens, the substitution of the O atom of xanthene, and hybridization with other fluorophores. 相似文献
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《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(11):3025-3029
Small‐molecule organic fluorophores spectrally active in the 800–950 nm region are sought‐after for their broad potential in biomedical and material applications. We have developed a new family of brightly fluorescent dyes ( ECX ) to meet this challenge. ECX dyes are transparent to the visible region, while strongly absorbing in the NIR region at approximately 880 nm. They emit at around 915 nm with a fluorescence quantum yield up to 13.3 %. ECX dyes exhibit high chemostability, high photostability, and low tendency to aggregate. Other merits of ECX dyes include low degree of solvatochromism and facile post‐synthetic derivatization. ECX dyes potentially make available the 800–950 nm region for spectroscopic and microscopic applications and are also expected to find broad material applications. 相似文献
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《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(30):8842-8846
Lithium hydride (LiH) has a strong effect on iron leading to an approximately 3 orders of magnitude increase in catalytic ammonia synthesis. The existence of lithium–iron ternary hydride species at the surface/interface of the catalyst were identified and characterized for the first time by gas‐phase optical spectroscopy coupled with mass spectrometry and quantum chemical calculations. The ternary hydride species may serve as centers that readily activate and hydrogenate dinitrogen, forming Fe‐(NH2)‐Li and LiNH2 moieties—possibly through a redox reaction of dinitrogen and hydridic hydrogen (LiH) that is mediated by iron—showing distinct differences from ammonia formation mediated by conventional iron or ruthenium‐based catalysts. Hydrogen‐associated activation and conversion of dinitrogen are discussed. 相似文献
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《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(39):11955-11958
Singlet oxygen is among the reactive oxygen species (ROS) with the shortest life‐times in aqueous media because of its extremely high reactivity. Therefore, designing sensors for detection of 1O2 is perhaps one of the most challenging tasks in the field of molecular probes. Herein, we report a highly selective and sensitive chemiluminescence probe ( SOCL‐CPP ) for the detection of 1O2 in living cells. The probe reacts with 1O2 to form a dioxetane that spontaneously decomposes under physiological conditions through a chemiexcitation pathway to emit green light with extraordinary intensity. SOCL‐CPP demonstrated promising ability to detect and image intracellular 1O2 produced by a photosensitizer in HeLa cells during photodynamic therapy (PDT) mode of action. Our findings make SOCL‐CPP the most effective known chemiluminescence probe for the detection of 1O2. We anticipate that our chemiluminescence probe for 1O2 imaging would be useful in PDT‐related applications and for monitoring 1O2 endogenously generated by cells in response to different stimuli. 相似文献
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