12 research outputs found
Facile Synthesis of Fluorescent Silica-Doped Polyvinylpyrrolidone Composites: From Cross-Linked Composite Film to Core–Shell Nanoparticles
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
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
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
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
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)-polyÂ(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
polyÂ(acrylic acid)Âs (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)Âclinical
translational development
Perylene-cored Star-shaped Polycations for Fluorescent Gene Vectors and Bioimaging
Two
star polycations, polyÂ(2-aminoethyl methacrylate) (PAEMA, <b>P1</b>) and polyÂ(2-(dimethylamino)Âethyl 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
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
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