12 research outputs found

    Facile Synthesis of Fluorescent Silica-Doped Polyvinylpyrrolidone Composites: From Cross-Linked Composite Film to Core–Shell Nanoparticles

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    Fluorescent silica-doped polyvinylpyrrolidone (PVP) composites with high optical properties have been successfully prepared in a one-pot synthesis through the incorporation of silica nanoparticles and dye molecules into the cross-linked PVP. Scanning electron microscopy, transmission electron microscopy, and fluorescence spectrometry are used to investigate the morphologies and optical properties of the composites. By adjusting the PVP content and reaction time, fluorescent silica-doped PVP film and fluorescent PVP-covered silica core–shell nanoparticles are obtained without stirring and under magnetic stirring, respectively. Because both the silica nanoparticles and the dye molecules react with ring-opened PVP, the composites exhibit highly stable optical properties. The obtained fluorescent composites may have potential applications in sensing and photovoltaic systems. The facile approach can be extended to the preparation of multifunctional fluorescent PVP composites by introducing other types of oxides

    Self-Assembly and Disassembly of Amphiphilic Zwitterionic Perylenediimide Vesicles for Cell Membrane Imaging

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    Animal cells have complicated dynamics of cell membrane structures which require desirable dyes for in vivo imaging. Here, an asymmetric amphiphilic zwitterionic perylenediimide (ZP) derivative has been constructed by introducing an octyl chain and a zwitterionic head to each imide position of perylenediimide chromophore. ZP could self-assemble into vesicles in aqueous solution. The aggregated ZP vesicles have been explored to image cell inner or surface membrane structures by a controlled disassembly process. After being taken up into cells, ZP vesicles disassemble into monomers and then incorporate into cell inner membranes. The vesicles can also disassemble in acid food and incorporate into cell surface membrane of gut cells. The research provides a new tool to label the complicated cell membrane structures with up to 3 days long-term labeling for life science applications

    “On–off–on” Switchable Sensor: A Fluorescent Spiropyran Responds to Extreme pH Conditions and Its Bioimaging Applications

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    A novel spiropyran that responds to both extreme acid and extreme alkali and has an “on–off–on” switch is reported. Benzoic acid at the indole N-position and carboxyl group at the indole 6-position contribute to the extreme acid response. The ionizations of carboxyl and phenolic hydroxyl groups cause the extreme alkali response. Moreover, the fluorescent imaging in bacterial cells under extreme pH conditions supports the mechanism of pH response

    Quantitative Detection Method of Hydroxyapatite Nanoparticles Based on Eu<sup>3+</sup> Fluorescent Labeling in Vitro and in Vivo

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    One major challenge for application of hydroxyapatite nanoparticles (nHAP) in nanomedicine is the quantitative detection method. Herein, we exploited one quantitative detection method for nHAP based on the Eu<sup>3+</sup> fluorescent labeling via a simple chemical coprecipitation method. The trace amount of nHAP in cells and tissues can be quantitatively detected on the basis of the fluorescent quantitative determination of Eu<sup>3+</sup> ions in nHAP crystal lattice. The lowest concentration of Eu<sup>3+</sup> ions that can be quantitatively detected is 0.5 nM using DELFIA enhancement solution. This methodology can be broadly applicable for studying the tissue distribution and metabolization of nHAP in vivo

    Terrylenediimide-Based Intrinsic Theranostic Nanomedicines with High Photothermal Conversion Efficiency for Photoacoustic Imaging-Guided Cancer Therapy

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    Activatable theranostic nanomedicines involved in photothermal therapy (PTT) have received constant attention as promising alternatives to traditional therapies in clinic. However, the theranostic nanomedicines widely suffer from instability and complicated nanostructures, which hamper potential clinical applications. Herein, we demonstrated a terrylenediimide (TDI)-poly­(acrylic acid) (TPA)-based nanomedicine (TNM) platform used as an intrinsic theranostic agent. As an exploratory paradigm in seeking biomedical applications, TDI was modified with poly­(acrylic acid)­s (PAAs), resulting in eight-armed, star-like TPAs composed of an outside hydrophilic PAA corona and an inner hydrophobic TDI core. TNMs were readily fabricated <i>via</i> spontaneous self-assembly. Without additional vehicle and cargo, the as-prepared TNMs possessed a robust nanostructure and high photothermal conversion efficiency up to approximately 41%. The intrinsic theranostic properties of TNMs for use in photoacoustic (PA) imaging by a multispectral optoacoustic tomography system and in mediating photoinduced tumor ablation were intensely explored. Our results suggested that the TNMs could be successfully exploited as intrinsic theranostic agents for PA imaging-guided efficient tumor PTT. Thus, these TNMs hold great potential for (pre)­clinical translational development

    Perylene-cored Star-shaped Polycations for Fluorescent Gene Vectors and Bioimaging

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    Two star polycations, poly­(2-aminoethyl methacrylate) (PAEMA, <b>P1</b>) and poly­(2-(dimethylamino)­ethyl methacrylate) (PDMAEMA, <b>P2</b>), have been synthesized with perylene diimide (PDI) as the central fluorophore. <sup>1</sup>H NMR and <sup>13</sup>C NMR are used to confirm the successful synthesis of a macromolecular initiator. Using ATRP strategy, <b>P1</b> and <b>P2</b> are obtained with narrow molecular weight distribution. The star polymers have good fluorescence properties in aqueous solution, which provides fluorescent tracing and imaging during gene delivery. Both <b>P1</b> and <b>P2</b> can efficiently condense DNA into stable nanoparticles. Transfection studies demonstrate that <b>P1</b> and <b>P2</b> deliver DNA into live cells with higher efficiency and lower cytotoxicity than polyethylenimine (PEI, 25 kDa). <b>P2</b> shows higher capacity for gene delivery than <b>P1</b> due to its better buffering and faster rate of cellular internalization

    DataSheet_1_Calcium nutrition nanoagent rescues tomatoes from mosaic virus disease by accelerating calcium transport and activating antiviral immunity.docx

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    As an essential structural, metabolic and signaling element, calcium shows low remobilization from old to young tissues in plants, restricting the nutrient-use efficiency and control efficacy against mosaic virus disease. Nanotechnology has been applied to prevent/minimize nutrient losses and improve the accessibility of poorly-available nutrients. Herein, the current study applied a star polycation (SPc) to prepare a calcium nutrition nanoagent. The SPc could assemble with calcium glycinate through hydrogen bond and Van der Waals force, forming stable spherical particles with nanoscale size (17.72 nm). Transcriptomic results revealed that the calcium glycinate/SPc complex could activate the expression of many transport-related genes and disease resistance genes in tomatoes, suggesting the enhanced transport and antiviral immunity of SPc-loaded calcium glycinate. Reasonably, the calcium transport was accelerated by 3.17 times into tomato leaves with the help of SPc, and the protective effect of calcium glycinate was remarkably improved to 77.40% and 67.31% toward tomato mosaic virus with the help of SPc after the third and fifth applications. Furthermore, SPc-loaded calcium glycinate could be applied to increase the leaf photosynthetic rate and control the unusual fast growth of tomatoes. The current study is the first success to apply nano-delivery system for enhanced calcium transport and antiviral immunity, which is beneficial for increasing nutrient-use efficiency and shows good prospects for field application.</p

    Bifunctional Magnetic-Fluorescent Nanoparticles: Synthesis, Characterization, and Cell Imaging

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    A new type of bifunctional magnetic-fluorescent Fe<sub>3</sub>O<sub>4</sub>@SiO<sub>2</sub>–PDI–PAA/Ca<sup>2+</sup> nanoparticles has been prepared by coating PDI-cored star polymers (PDI–PAA) onto the surface of Fe<sub>3</sub>O<sub>4</sub>@SiO<sub>2</sub> core–shell nanostructures. The morphology and properties of the composite nanoparticles are investigated by transmission electron microscopy, ultraviolet–visible spectrometry, fluorescence spectrometry, and vibrating sample magnetometry. The composite nanoparticles display a strong red emission and superparamagnetic behavior at room temperature. The cell viability and uptake assays reveal good biocompatibility of these hybrid nanoparticles. Hence, the composite nanoparticles are of potential to be further explored as therapeutic vector in biomedical field
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