title: Aggregation-Induced Emission Luminogen-Embedded Silica Nanoparticles Containing DNA Aptamers for Targeted Cell Imaging.
abstract: Conventional fluorophores usually undergo aggregation-caused quenching (ACQ), which limits the loading amount of these fluorophores in nanoparticles for bright fluorescence imaging. On the contrary, fluorophores with aggregation-induced emission (AIE) characteristics are strongly fluorescent in their aggregate states and have been an ideal platform for developing highly fluorescent nanomaterials, such as fluorescent silica nanoparticles (FSNPs). In this work, AIE luminogens based on salicylaldehyde hydrazones were embedded in silica nanoparticles through a facile noncovalent approach, which afforded AIE-FSNPs emitting much brighter fluorescence than that of some commercial fluorescein-doped silica and polystyrene nanoparticles. These AIE-FSNPs displaying multiple fluorescence colors were fabricated by a general method, and they underwent much less fluorescence variation due to environmental pH changes compared with fluorescein-hybridized FSNPs. In addition, a DNA aptamer specific to nucleolin was functionalized on the surface of AIE-FSNPs for targeted cell imaging. Fluorescent microscopy and flow cytometry studies both revealed highly selective fluorescence staining of MCF-7 (a cancer cell line with nucleolin overexpression) over MCF-10A (normal) cells by the aptamer-functionalized AIE-FSNPs. The fluorescence imaging in different color channels was achieved using AIE-FSNPs containing each of the AIE luminogens, as well as photoactivatable fluorescent imaging of target cells by the caged AIE fluorophore.
authors.affiliation: Department of Chemistry, Beijing Key Laboratory for Microanalytical Methods and Instrumentation, Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical Biology (Ministry of Education), Tsinghua University , Beijing 100084, China.
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Wang
authors.affiliation: National Institute of Metrology , Beijing 100029, China.
authors.forename: Panshu
authors.initials: P
authors.lastname: Song
authors.affiliation: Department of Chemistry, Beijing Key Laboratory for Microanalytical Methods and Instrumentation, Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical Biology (Ministry of Education), Tsinghua University , Beijing 100084, China.
authors.forename: Lu
authors.initials: L
authors.lastname: Peng
authors.affiliation: Department of Chemistry, Beijing Key Laboratory for Microanalytical Methods and Instrumentation, Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical Biology (Ministry of Education), Tsinghua University , Beijing 100084, China.
authors.forename: Aijun
authors.initials: A
authors.lastname: Tong
authors.affiliation: Department of Chemistry, Beijing Key Laboratory for Microanalytical Methods and Instrumentation, Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical Biology (Ministry of Education), Tsinghua University , Beijing 100084, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Xiang
mesh_terms: D000906:Antibodies / Q000378:metabolism; D052157:Aptamers, Nucleotide / Q000737:chemistry*; D016923:Cell Death / Q000187:drug effects; D005456:Fluorescent Dyes / Q000737:chemistry*; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D061986:MCF-7 Cells; D053758:Nanoparticles / Q000737:chemistry* / Q000633:toxicity; D012822:Silicon Dioxide / Q000737:chemistry* / Q000633:toxicity; D013050:Spectrometry, Fluorescence; D055672:Static Electricity; D014466:Ultraviolet Rays
chemical_list: D000906:Antibodies; D052157:Aptamers, Nucleotide; D005456:Fluorescent Dyes; D012822:Silicon Dioxide
keywords: DNA aptamer; aggregation-induced emission; cell imaging; photoactivatable fluorescence; silica nanoparticle