13 research outputs found
Photoresponsive CHA-Integrated Self-Propelling 3D DNA Walking Amplifier within the Concentration Localization Effect of DNA Molecular Framework Enables Highly Efficient Fluorescence Bioimaging
While three-dimensional (3D) DNA
walking amplifiers hold considerable
promise in the construction of advanced DNA-based fluorescent biosensors
for bioimaging, they encounter certain difficulties such as inadequate
sensitivity, premature activation, the need for exogenous propelling
forces, and low reaction rates. In this contribution, a variety of
profitable solutions have been explored. First, a catalytic hairpin
assembly (CHA)-achieved nonenzymatic isothermal nucleic acid amplification
is integrated to enhance sensitivity. Subsequently, one DNA component
is simply functionalized with a photocleavage-bond to conduct a photoresponsive
manner, whereby the target recognition occurs only when the biosensor
is exposed to an external ultraviolet light source, overcoming premature
activation during biodelivery. Furthermore, a special self-propelling
walking mechanism is implemented by reducing biothiols to MnO2 nanosheets, thereby propelling forces that are self-supplied
to a Mn2+-reliant DNAzyme. By carrying the biosensing system
with a DNA molecular framework to induce a unique concentration localization
effect, the nucleic acid contact reaction rate is notably elevated
by 6 times. Following these, an ultrasensitive in vitro detection
performance with a limit of detection down to 2.89 fM is verified
for a cancer-correlated microRNA biomarker (miRNA-21). Of particular
importance, our multiple concepts combined 3D DNA walking amplifier
that enables highly efficient fluorescence bioimaging in live cells
and even bodies, exhibiting a favorable application prospect in disease
analysis
Myosin-Driven Intercellular Transportation of Wheat Germ Agglutinin Mediated by Membrane Nanotubes between Human Lung Cancer Cells
Membrane nanotubes can facilitate direct intercellular communication between cells and provide a unique channel for intercellular transfer of cellular contents. However, the transport mechanisms of membrane nanotubes remain poorly understood between cancer cells. Also largely unknown is the transport pattern mediated by membrane nanotubes. In this work, wheat germ agglutinin (WGA), a widely used drug carrier and potential antineoplastic drug, was labeled with quantum dots (QDs-WGA) as a model for exploring the intercellular transportation <i>via</i> membrane nanotubes. We found that membrane nanotubes allowed effective transfer of QDs-WGA. Long-term single-particle tracking indicated that the movements of QDs-WGA exhibited a slow and directed motion pattern in nanotubes. Significantly, the transport of QDs-WGA was driven by myosin molecular motors in an active and unidirectional manner. These results contribute to a better understanding of cell-to-cell communication for cancer research
Myosin-Driven Intercellular Transportation of Wheat Germ Agglutinin Mediated by Membrane Nanotubes between Human Lung Cancer Cells
Membrane nanotubes can facilitate direct intercellular communication between cells and provide a unique channel for intercellular transfer of cellular contents. However, the transport mechanisms of membrane nanotubes remain poorly understood between cancer cells. Also largely unknown is the transport pattern mediated by membrane nanotubes. In this work, wheat germ agglutinin (WGA), a widely used drug carrier and potential antineoplastic drug, was labeled with quantum dots (QDs-WGA) as a model for exploring the intercellular transportation <i>via</i> membrane nanotubes. We found that membrane nanotubes allowed effective transfer of QDs-WGA. Long-term single-particle tracking indicated that the movements of QDs-WGA exhibited a slow and directed motion pattern in nanotubes. Significantly, the transport of QDs-WGA was driven by myosin molecular motors in an active and unidirectional manner. These results contribute to a better understanding of cell-to-cell communication for cancer research
Myosin-Driven Intercellular Transportation of Wheat Germ Agglutinin Mediated by Membrane Nanotubes between Human Lung Cancer Cells
Membrane nanotubes can facilitate direct intercellular communication between cells and provide a unique channel for intercellular transfer of cellular contents. However, the transport mechanisms of membrane nanotubes remain poorly understood between cancer cells. Also largely unknown is the transport pattern mediated by membrane nanotubes. In this work, wheat germ agglutinin (WGA), a widely used drug carrier and potential antineoplastic drug, was labeled with quantum dots (QDs-WGA) as a model for exploring the intercellular transportation <i>via</i> membrane nanotubes. We found that membrane nanotubes allowed effective transfer of QDs-WGA. Long-term single-particle tracking indicated that the movements of QDs-WGA exhibited a slow and directed motion pattern in nanotubes. Significantly, the transport of QDs-WGA was driven by myosin molecular motors in an active and unidirectional manner. These results contribute to a better understanding of cell-to-cell communication for cancer research
Influence of Three Anionic Gemini Surfactants with Different Chain Lengths on the Optical Properties of a Cationic Polyfluorene
The
effects of three sulfonate gemini surfactants with different
hydrophobic chain lengths (8, 10, and 12 carbon atoms) on the optical
properties of a fluorene-based conjugated cationic polymer polyÂ{[9,9-bisÂ(6′-<i>N</i>,<i>N</i>,<i>N</i>-trimethylammonium)Âhexyl]-fluorene-phenylene}
bromide (PFP) dissolved in DMSO–water solutions (4% v/v) or
water were investigated, respectively. When surfactants with PFP dissolved
in DMSO–water solutions (4% v/v) are incubated, a decrease
in photoluminescence (PL) intensity and a red shift of emission maxima
are obtained at low surfactant concentrations. Intriguingly, two different
Stern–Volmer constants (<i>K</i><sub>SV1</sub> and <i>K</i><sub>SV2</sub>) are obtained and analyzed in detail for
the first time. Further increase in the surfactant concentration enhanced
PL intensity, and distinct blue shifts of both absorption and emission
maxima are observed. Importantly, the turning point between the emission
quenching and enhancement is closely related to the hydrophobic chain
length: the longer the chain length, the earlier the turning point
appears. Simulation studies provide strong evidence to explain these
phenomena. Surface tension measurements show more insight on the interactions
between PFP and surfactant. On the contrary, no emission quenching
is obtained at low surfactant concentrations for PFP dissolved in
water
Verrucaria indet.
Membrane nanotubes can facilitate direct intercellular communication between cells and provide a unique channel for intercellular transfer of cellular contents. However, the transport mechanisms of membrane nanotubes remain poorly understood between cancer cells. Also largely unknown is the transport pattern mediated by membrane nanotubes. In this work, wheat germ agglutinin (WGA), a widely used drug carrier and potential antineoplastic drug, was labeled with quantum dots (QDs-WGA) as a model for exploring the intercellular transportation <i>via</i> membrane nanotubes. We found that membrane nanotubes allowed effective transfer of QDs-WGA. Long-term single-particle tracking indicated that the movements of QDs-WGA exhibited a slow and directed motion pattern in nanotubes. Significantly, the transport of QDs-WGA was driven by myosin molecular motors in an active and unidirectional manner. These results contribute to a better understanding of cell-to-cell communication for cancer research
Myosin-Driven Intercellular Transportation of Wheat Germ Agglutinin Mediated by Membrane Nanotubes between Human Lung Cancer Cells
Membrane nanotubes can facilitate direct intercellular communication between cells and provide a unique channel for intercellular transfer of cellular contents. However, the transport mechanisms of membrane nanotubes remain poorly understood between cancer cells. Also largely unknown is the transport pattern mediated by membrane nanotubes. In this work, wheat germ agglutinin (WGA), a widely used drug carrier and potential antineoplastic drug, was labeled with quantum dots (QDs-WGA) as a model for exploring the intercellular transportation <i>via</i> membrane nanotubes. We found that membrane nanotubes allowed effective transfer of QDs-WGA. Long-term single-particle tracking indicated that the movements of QDs-WGA exhibited a slow and directed motion pattern in nanotubes. Significantly, the transport of QDs-WGA was driven by myosin molecular motors in an active and unidirectional manner. These results contribute to a better understanding of cell-to-cell communication for cancer research
Myosin-Driven Intercellular Transportation of Wheat Germ Agglutinin Mediated by Membrane Nanotubes between Human Lung Cancer Cells
Membrane nanotubes can facilitate direct intercellular communication between cells and provide a unique channel for intercellular transfer of cellular contents. However, the transport mechanisms of membrane nanotubes remain poorly understood between cancer cells. Also largely unknown is the transport pattern mediated by membrane nanotubes. In this work, wheat germ agglutinin (WGA), a widely used drug carrier and potential antineoplastic drug, was labeled with quantum dots (QDs-WGA) as a model for exploring the intercellular transportation <i>via</i> membrane nanotubes. We found that membrane nanotubes allowed effective transfer of QDs-WGA. Long-term single-particle tracking indicated that the movements of QDs-WGA exhibited a slow and directed motion pattern in nanotubes. Significantly, the transport of QDs-WGA was driven by myosin molecular motors in an active and unidirectional manner. These results contribute to a better understanding of cell-to-cell communication for cancer research
Myosin-Driven Intercellular Transportation of Wheat Germ Agglutinin Mediated by Membrane Nanotubes between Human Lung Cancer Cells
Membrane nanotubes can facilitate direct intercellular communication between cells and provide a unique channel for intercellular transfer of cellular contents. However, the transport mechanisms of membrane nanotubes remain poorly understood between cancer cells. Also largely unknown is the transport pattern mediated by membrane nanotubes. In this work, wheat germ agglutinin (WGA), a widely used drug carrier and potential antineoplastic drug, was labeled with quantum dots (QDs-WGA) as a model for exploring the intercellular transportation <i>via</i> membrane nanotubes. We found that membrane nanotubes allowed effective transfer of QDs-WGA. Long-term single-particle tracking indicated that the movements of QDs-WGA exhibited a slow and directed motion pattern in nanotubes. Significantly, the transport of QDs-WGA was driven by myosin molecular motors in an active and unidirectional manner. These results contribute to a better understanding of cell-to-cell communication for cancer research
Fluorescence Detection of H5N1 Virus Gene Sequences Based on Optical Tweezers with Two-Photon Excitation Using a Single Near Infrared Nanosecond Pulse Laser
We
present an analytical platform by combining near-infrared optical
tweezers with two-photon excitation for fluorescence detection of
H5N1 virus gene sequences. A heterogeneous enrichment strategy, which
involved polystyrene (PS) microsphere and quantum dots (QDs), was
adopted. The final hybrid-conjugate microspheres were prepared by
a facile one-step hybridization procedure by using PS microspheres
capturing target DNA and QDs tagging, respectively. Quantitative detection
was achieved by the optical tweezers setup with a low-cost 1064 nm
nanosecond pulse laser for both optical trapping and two-photon excitation
for the same hybrid-conjugate microsphere. The detection limits for
both neuraminidase (NA) gene sequences and hemagglutinin (HA) gene
sequences are 16–19 pM with good selectivity for one-base mismatch,
which is approximately 1 order of magnitude lower than the most existing
fluorescence-based analysis method. Besides, because of the fact that
only signal from the trapped particle is detected upon two-photon
excitation, this approach showed extremely low background in fluorescence
detection and was successfully applied to directly detect target DNA
in human whole serum without any separation steps and the corresponding
results are very close to that in buffer solution, indicating the
strong anti-interference ability of this method. Therefore, it can
be expected to be an emerging alternative for straightforward detecting
target species in complex samples with a simple procedure and high-throughput