17 research outputs found
Nanomagnetic-Mediated Drug Delivery for The Treatment of Dental Disease
Maintaining the vitality of the dental pulp, the highly innervated and highly vascular, innermost layer of the tooth, is a critical goal of any dental procedure. Upon injury, targeting the pulp with specific therapies is challenging because it is encased in hard tissues. This project describes a method that can effectively deliver therapeutic agents to the pulp. This method relies on the use of nanoparticles that can be actively steered using magnetic forces to the pulp, traveling through naturally occurring channels in the dentin (the middle layer of the tooth). This method can reduce the inflammation of injured pulp and improve the penetration of dental adhesives into dentin. Such a delivery method would be less expensive, and both less painful and less traumatic than existing therapeutic options available for treatment of injured dental pulp. This technique would be simple and could be readily translated to clinical use
Rapid detection of influenza A viruses using a real-time reverse transcription recombinase-aided amplification assay
IntroductionInfluenza A viruses (IAVs) are important pathogens of respiratory infections, causing not only seasonal influenza but also influenza pandemics and posing a global threat to public health. IAVs infection spreads rapidly, widely, and across species, causing huge losses, especially zoonotic IAVs infections that are more harmful. Fast and sensitive detection of IAVs is critical for controlling the spread of this disease.MethodsHere, a real-time reverse transcription recombinase-aided amplification (real-time RT-RAA) assay targeting conserved positions in the matrix protein gene (M gene) of IAVs, is successfully established to detect IAVs. The assay can be completed within 20 min at 42°C.ResultsThe sensitivity of the real-time RT-RAA assay was 142 copies per reaction at 95% probability, which was comparable to the sensitivity of the RT-qPCR assay. The specificity assay showed that the real-time RT-RAA assay was specific to IAVs, and there was no cross-reactivity with other important viruses. In addition, 100%concordance between the real-time RT-RAA and RT-qPCR assays was achieved after testing 120 clinical specimens.DiscussionThe results suggested that the real-time RT-RAA assay we developed was a specific, sensitive and reliable diagnostic tool for the rapid detection of IAVs
New species of Limnophyes Eaton (Diptera, Chironomidae) from China and synonymy of L. fuscipygmus Tokunaga, 1940
Two new species, L. minerus Liu & Yan, sp. nov. and L. subtilus Liu & Yan, sp. nov. are described and illustrated as adult males. Limnophyes minimus (Meigen, 1818) is assigned as a senior synonym of L. minerus Tokunaga, 1940. A key to males of Limnophyes from China is presented
Controlled Growth Cu<sub>2</sub>S Nanoarrays with High-Performance Photothermal Properties
The controlled growth of Cu2S nanoarrays was constructed by a facile two-step impregnation synthesis route. The as-synthesized Cu2S/CuO@Cu samples were precisely characterized in terms of surface morphology, phase, composition, and oxidation states. At the laser irradiation of 808 nm, Cu2S/CuO@Cu heated up to 106 °C from room temperature in 120 s, resulting in an excellent photothermal conversion performance. The Cu2S/CuO@Cu exhibited excellent cycling performance—sustaining the photothermal performance during five heating-cooling cycles. The finite difference time domain (FDTD) simulation of optical absorption and electric field distributions assured the accuracy and reliability of the developed experimental conditions for acquiring the best photothermal performance of Cu2S/CuO@Cu
Designated-Tailoring on {100} Facets of Cu2O Nanostructures: From Octahedral to Its Different Truncated Forms
A facile template-free controlled synthesis of Cu2O architectures from octahedral to its different truncated forms is
successfully achieved. It is found that the precursor formation temperature is crucial to the designated-tailoring on the {100} facets of
Cu2O crystals, which can modify the ratio (R) between
the growth rates along the 〈100〉 and 〈111〉 directions, leading to the formation of the initial structures with different shapes. The multiple morphologies can be evolved from these varied
initial structures via the synergic effect of oriented attachment and ripening mechanism. This template-free complex precursor-based solution route has provided
an innovative approach to design the {100} facets with different sizes to further enrich the current morphologies of Cu2O crystals
Wearable Noninvasive Glucose Sensor Based on Cu<sub>x</sub>O NFs/Cu NPs Nanocomposites
Designing highly active material to fabricate a high-performance noninvasive wearable glucose sensor was of great importance for diabetes monitoring. In this work, we developed CuxO nanoflakes (NFs)/Cu nanoparticles (NPs) nanocomposites to serve as the sensing materials for noninvasive sweat-based wearable glucose sensors. We involve CuCl2 to enhance the oxidation of Cu NPs to generate Cu2O/CuO NFs on the surface. Due to more active sites endowed by the CuxO NFs, the as-prepared sample exhibited high sensitivity (779 μA mM−1 cm−2) for noninvasive wearable sweat sensing. Combined with a low detection limit (79.1 nM), high selectivity and the durability of bending and twisting, the CuxO NFs/Cu NPs-based sensor can detect the glucose level change of sweat in daily life. Such a high-performance wearable sensor fabricated by a convenient method provides a facile way to design copper oxide nanomaterials for noninvasive wearable glucose sensors
Wearable, stable, highly sensitive hydrogel–graphene strain sensors
A stable and highly sensitive graphene/hydrogel strain sensor is designed by introducing glycerol as a co-solvent in the formation of a hydrogel substrate and then casting a graphene solution onto the hydrogel in a simple, two-step method. This hydrogel-based strain sensor can effectively retain water in the polymer network due to the formation of strong hydrogen bonding between glycerol and water. The addition of glycerol not only enhances the stability of the hydrogel over a wider temperature range, but also increases the stretchability of the hydrogel from 800% to 2000%. The enhanced sensitivity can be attributed to the graphene film, whereby the graphene flakes redistribute to optimize the contact area under different strains. The careful design enables this sensor to be used in both stretching and bending modes. As a demonstration, the as-prepared strain sensor was applied to sense the movement of finger knuckles. Given the outstanding performance of this wearable sensor, together with the proposed scalable fabrication method, this stable and sensitive hydrogel strain sensor is considered to have great potential in the field of wearable sensors
Immobilized Seed-Mediated Growth of Two-Dimensional Array of Metallic Nanocrystals with Asymmetric Shapes
Bottom-up fabrication
of such arrays with specific orientation
of nanoparticles remains a challenge. In this paper, we report an
immobilized seed-mediated growth strategy for the fabrication of two-dimensional
(2D) arrays of mono- and bimetallic polyhedral nanocrystals with well-defined
shapes and orientations on a substrate. This method relies on the
controlled solution-phase deposition of metals (<i>i.e.</i>, Au and Pd) on a selectively exposed surface of self-assembled seed
nanoparticles that are immobilized on a substrate through collapsed
polymer brushes. By using this approach, we demonstrated the preparation
of various 2D arrays of shaped Au nanocrystals and Au core/Pd shell
nanocrystals with asymmetric geometry of two halves and controlled
orientations with respect to the substrate. The shape evolution of
seeds to final nanocrystals was systematically monitored and evaluated
by electron microscopic imaging. Our study suggests that the shape
and orientation of nanocrystals within arrays is determined by the
preferential orientation of assembled seed nanoparticles on the substrate
and controllable deposition of metals on exposed crystal facets of
immobilized seeds. The synthetic approach we developed presents an
important addition to current tools for the fabrication of substrate-supported
functional nanostructures
Sweat-based wearable energy harvesting-storage hybrid textile devices
This study demonstrates the first example of a stretchable and wearable textile-based hybrid supercapacitor–biofuel cell (SC–BFC) system. The hybrid device, screen-printed on both sides of the fabric, is designed to scavenge biochemical energy from the wearer's sweat using the BFC module and to store it in the SC module for subsequent use. The BFC relies on lactate, which is oxidized enzymatically to generate electricity. The generated bioenergy is stored directly and rapidly in the printed in-plane SCs. The SC energy-storage module employs MnO2/carbon nanotube composites that offer high areal capacitance and cycling electrochemical stability. Both printed SC and BFC devices rely on optimal elastomer-containing ink formulations and serpentine structure patterns that impart a stable electrochemical performance after a variety of mechanical deformations. Such a fabrication route ensures that the energy-harvesting and storage properties of the two integrated devices are not compromised. The SC–BFC hybrid system can thus deliver stable output over long charging periods, boost the voltage output of the BFC, and exhibit favorable cycling ability. Such attractive performance, demonstrated in successful on-body testing, along with the unique architecture and low-cost scalable fabrication, make the new garment-ased hybrid energy device useful for meeting the power and mechanical resiliency requirements of wearable electronics and smart textiles
Cooperative Assembly of Magneto-Nanovesicles with Tunable Wall Thickness and Permeability for MRI-Guided Drug Delivery
This
article describes the fabrication of nanosized magneto-vesicles
(MVs) comprising tunable layers of densely packed superparamagnetic
iron oxide nanoparticles (SPIONs) in membranes via cooperative assembly
of polymer-tethered SPIONs and free poly(styrene)-<i>b</i>-poly(acrylic acid) (PS-<i>b</i>-PAA). The membrane thickness
of MVs could be well controlled from 9.8 to 93.2 nm by varying the
weight ratio of PS-<i>b</i>-PAA to SPIONs. The increase
in membrane thickness was accompanied by the transition from monolayer
MVs, to double-layered MVs and to multilayered MVs (MuMVs). This can
be attributed to the variation in the hydrophobic/hydrophilic balance
of polymer-grafted SPIONs upon the insertion and binding of PS-<i>b</i>-PAA onto the surface of nanoparticles. Therapeutic agents
can be efficiently encapsulated in the hollow cavity of MVs and the
release of payload can be tuned by varying the membrane thickness
of nanovesicles. Due to the high packing density of SPIONs, the MuMVs
showed the highest magnetization and transverse relaxivity rate (<i>r</i><sub>2</sub>) in magnetic resonance imaging (MRI) among
these MVs and individual SPIONs. Upon intravenous injection, doxorubicin-loaded
MuMVs conjugated with RGD peptides could be effectively enriched at
tumor sites due to synergetic effect of magnetic and active targeting.
As a result, they exhibited drastically enhanced signal in MRI, improved
tumor delivery efficiency of drugs as well as enhanced antitumor efficacy,
compared with groups with only magnetic or active targeting strategy.
The unique nanoplatform may find applications in effective disease
control by delivering imaging and therapy to organs/tissues that are
not readily accessible by conventional delivery vehicles