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Nanomaterials, Volume 10, Issue 11 (November 2020) – 232 articles

Cover Story (view full-size image): The SnO2 nanosheet transistor at a 4.5 nm thickness has achieved record-high 136 cm2/Vs field-effect mobility among top-gate metal-oxide transistors, significantly better 1.5 × 108 on-current/off-current than standard silicon transistors, and fast turn-on 0.11 V/decade subthreshold slope for low power operation. This transistor was fabricated at a 350 °C temperature on amorphous SiO2 dielectric of the integrated circuit (IC), which is much lower than the typical 1000 °C for single-crystal silicon transistors. This high-performance device and the energy-saving low-temperature process are the key technologies for monolithic three-dimensional brain-mimicking ICs that have extremely large interconnect density, superior fast speed, and ultralow power consumption. View this paper.
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Article
Hair Follicle Targeting and Dermal Drug Delivery with Curcumin Drug Nanocrystals—Essential Influence of Excipients
Nanomaterials 2020, 10(11), 2323; https://doi.org/10.3390/nano10112323 - 23 Nov 2020
Cited by 7 | Viewed by 996
Abstract
Many active pharmaceutical ingredients (API) possess poor aqueous solubility and thus lead to poor bioavailability upon oral administration and topical application. Nanocrystals have a well-established, universal formulation approach to overcome poor solubility. Various nanocrystal-based products have entered the market for oral application. However, [...] Read more.
Many active pharmaceutical ingredients (API) possess poor aqueous solubility and thus lead to poor bioavailability upon oral administration and topical application. Nanocrystals have a well-established, universal formulation approach to overcome poor solubility. Various nanocrystal-based products have entered the market for oral application. However, their use in dermal formulations is relatively novel. Previous studies confirmed that nanocrystals are a superior formulation principle to improve the dermal penetration of poorly soluble API. Other studies showed that nanocrystals can also be used to target the hair follicles where they create a drug depot, enabling long acting drug therapy with only one application. Very recent studies show that also the vehicle in which the nanocrystals are incorporated can have a tremendous influence on the pathway of the API and the nanocrystals. In order to elucidate the influence of the excipient in more detail, a systematic study was conducted to investigate the influence of excipients on the penetration efficacy of the formulated API and the pathway of nanocrystals upon dermal application. Results showed that already small quantities of excipients can strongly affect the passive dermal penetration of curcumin and the hair follicle targeting of curcumin nanocrystals. The addition of 2% ethanol promoted hair follicle targeting of nanocrystals and hampered passive diffusion into the stratum corneum of the API, whereas the addition of glycerol hampered hair follicle targeting and promoted passive diffusion. Propylene glycol was found to promote both pathways. In fact, the study proved that formulating nanocrystals to improve the bioefficacy of poorly soluble API upon dermal application is highly effective. However, this is only true, if the correct excipient is selected for the formulation of the vehicle. The study also showed that excipients can be used to allow for a targeted dermal drug delivery, which enables to control if API should be delivered via passive diffusion and/or as drug reservoir by depositing API in the hair follicles. Full article
(This article belongs to the Special Issue Implementation of Nanomaterials for Drug Delivery)
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Article
Synthesis and Catalytic Application of Silver Nanoparticles Supported on Lactobacillus kefiri S-Layer Proteins
Nanomaterials 2020, 10(11), 2322; https://doi.org/10.3390/nano10112322 - 23 Nov 2020
Cited by 1 | Viewed by 653
Abstract
Research on nanoparticles obtained on biological supports is a topic of growing interest in nanoscience, especially regarding catalytic applications. Silver nanoparticles (AgNPs) have been studied due to their low toxicity, but they tend to aggregation, oxidation, and low stability. In this work, we [...] Read more.
Research on nanoparticles obtained on biological supports is a topic of growing interest in nanoscience, especially regarding catalytic applications. Silver nanoparticles (AgNPs) have been studied due to their low toxicity, but they tend to aggregation, oxidation, and low stability. In this work, we synthesized and characterized AgNPs supported on S-layer proteins (SLPs) as bidimensional regularly arranged biotemplates. By different reduction strategies, six AgNPs of variable sizes were obtained on two different SLPs. Transmission electron microscopy (TEM) images showed that SLPs are mostly decorated by evenly distributed AgNPs; however, a drastic reduction by NaBH4 led to large AgNPs whereas a smooth reduction with H2 or H2/NaBH4 at low concentration leads to smaller AgNPs, regardless of the SLP used as support. All the nanosystems showed conversion values between 75–80% of p-nitrophenol to p-aminophenol, however, the increment in the AgNPs size led to a great decrease in Kapp showing the influence of reduction strategy in the performance of the catalysts. Density functional theory (DFT) calculations indicated that the adsorption of p-nitrophenolate species through the nitro group is the most favored mechanism, leading to p-aminophenol as the only feasible product of the reaction, which was corroborated experimentally. Full article
(This article belongs to the Special Issue Nanostructured Catalysts for Sustainable Applications)
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Article
From Chip Size to Wafer-Scale Nanoporous Gold Reliable Fabrication Using Low Currents Electrochemical Etching
Nanomaterials 2020, 10(11), 2321; https://doi.org/10.3390/nano10112321 - 23 Nov 2020
Viewed by 640
Abstract
We report a simple, scalable route to wafer-size processing for fabrication of tunable nanoporous gold (NPG) by the anodization process at low constant current in a solution of hydrofluoric acid and dimethylformamide. Microstructural, optical, and electrochemical investigations were employed for a systematic analysis [...] Read more.
We report a simple, scalable route to wafer-size processing for fabrication of tunable nanoporous gold (NPG) by the anodization process at low constant current in a solution of hydrofluoric acid and dimethylformamide. Microstructural, optical, and electrochemical investigations were employed for a systematic analysis of the sample porosity evolution while increasing the anodization duration, namely the small angle X-ray scattering (SAXS) technique and electrochemical impedance spectroscopy (EIS). Whereas the SAXS analysis practically completes the scanning electronic microscopy (SEM) investigations and provides data about the impact of the etching time on the nanoporous gold layers in terms of fractal dimension and average pore surface area, the EIS analysis was used to estimate the electroactive area, the associated roughness factor, as well as the heterogeneous electron transfer rate constant. The bridge between the analyses is made by the scanning electrochemical microscopy (SECM) survey, which practically correlates the surface morphology with the electrochemical activity. The results were correlated to endorse the control over the gold film nanostructuration process deposited directly on the substrate that can be further subjected to different technological processes, retaining its properties. The results show that the anodization duration influences the surface area, which subsequently modifies the properties of NPG, thus enabling tuning the samples for specific applications, either optical or chemical. Full article
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Article
Novel Pt-Ag3PO4/CdS/Chitosan Nanocomposite with Enhanced Photocatalytic and Biological Activities
Nanomaterials 2020, 10(11), 2320; https://doi.org/10.3390/nano10112320 - 23 Nov 2020
Cited by 4 | Viewed by 1499
Abstract
Decorating photocatalysts with noble metal nanoparticles (e.g., Pt) often increases the catalysts’ photocatalytic activity and biomedical properties. Here, a simple and inexpensive method has been developed to prepare a Pt-Ag3PO4/CdS/chitosan composite, which was characterized and used for the visible [...] Read more.
Decorating photocatalysts with noble metal nanoparticles (e.g., Pt) often increases the catalysts’ photocatalytic activity and biomedical properties. Here, a simple and inexpensive method has been developed to prepare a Pt-Ag3PO4/CdS/chitosan composite, which was characterized and used for the visible light-induced photocatalytic and antibacterial studies. This synthesized composite showed superior photocatalytic activity for methylene blue degradation as a hazardous pollutant (the maximum dye degradation was observed in 90 min of treatment) and killing of Gram positive bacterial (Staphylococcus aureus and Bacillus cereus) as well as Gram negative bacteria (Klebsiella pneumoniae, Salmonella typhimurium, Escherichia coli, and Pseudomonas aeruginosa) under visible light irradiation. The antibacterial activity of CdS, CdS/Ag3PO4, and Pt-Ag3PO4/CdS/chitosan against E. coli, Pseudomonas aeruginosa, Salmonella typhimurium, Klebsiella pneumoniae, Staphylococcus aureus, and Bacillus cereus showed the zone of inhibition (mm) under visible light and under dark conditions at a concentration of 20 µg mL−1. Furthermore, the cell viability of the CdS/chitosan, Ag3PO4, Ag3PO4/CdS/chitosan, and Pt-Ag3PO4/CdS/chitosan were investigated on the human embryonic kidney 293 cells (HEK-293), Henrietta Lacks (HeLa), human liver cancer cell line (HepG2), and pheochromocytoma (PC12) cell lines. In addition, the results indicated that the photodegradation rate for Pt-Ag3PO4/CdS/chitosan is 3.53 times higher than that of CdS and 1.73 times higher than that of the CdS/Ag3PO4 composite. Moreover, Pt-Ag3PO4/CdS/chitosan with an optimal amount of CdS killed large areas of different bacteria and different cells separately in a shorter time period under visible-light irradiation, which shows significantly higher efficiency than pure CdS and other CdS/Ag3PO4 composites. The superb performances of this composite are attributed to its privileged properties, such as retarded recombination of photoinduced electron/hole pairs and a large specific surface area, making Pt-Ag3PO4/CdS/chitosan a valuable composite that can be deployed for a range of important applications, such as visible light-induced photocatalysis and antibacterial activity. Full article
(This article belongs to the Special Issue Design and Fabrication of Organic/Inorganic Nanocomposites)
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Article
Enhancing and Tuning the Nonlinear Optical Response and Wavelength-Agile Strong Optical Limiting Action of N-octylamine Modified Fluorographenes
Nanomaterials 2020, 10(11), 2319; https://doi.org/10.3390/nano10112319 - 23 Nov 2020
Cited by 1 | Viewed by 862
Abstract
Fluorographene has been recently shown to be a suitable platform for synthesizing numerous graphene derivatives with desired properties. In that respect, N-octylamine-modified fluorographenes with variable degrees of functionalization are studied and their nonlinear optical properties are assessed using 4 ns pulses. A [...] Read more.
Fluorographene has been recently shown to be a suitable platform for synthesizing numerous graphene derivatives with desired properties. In that respect, N-octylamine-modified fluorographenes with variable degrees of functionalization are studied and their nonlinear optical properties are assessed using 4 ns pulses. A very strong enhancement of the nonlinear optical response and a very efficient optical limiting action are observed, being strongly dependent on the degree of functionalization of fluorographene. The observed enhanced response is attributed to the increasing number of defects because of the incorporation of N-heteroatoms in the graphitic network upon functionalization with N-octylamine. The present work paves the way for the controlled covalent functionalization of graphene enabling a scalable access to a wide portfolio of graphene derivatives with custom-tailored properties. Full article
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Review
An Updated Review on Silver Nanoparticles in Biomedicine
Nanomaterials 2020, 10(11), 2318; https://doi.org/10.3390/nano10112318 - 23 Nov 2020
Cited by 17 | Viewed by 3216
Abstract
Silver nanoparticles (AgNPs) represent one of the most explored categories of nanomaterials for new and improved biomaterials and biotechnologies, with impressive use in the pharmaceutical and cosmetic industry, anti-infective therapy and wound care, food and the textile industry. Their extensive and versatile applicability [...] Read more.
Silver nanoparticles (AgNPs) represent one of the most explored categories of nanomaterials for new and improved biomaterials and biotechnologies, with impressive use in the pharmaceutical and cosmetic industry, anti-infective therapy and wound care, food and the textile industry. Their extensive and versatile applicability relies on the genuine and easy-tunable properties of nanosilver, including remarkable physicochemical behavior, exceptional antimicrobial efficiency, anti-inflammatory action and antitumor activity. Besides commercially available and clinically safe AgNPs-based products, a substantial number of recent studies assessed the applicability of nanosilver as therapeutic agents in augmented and alternative strategies for cancer therapy, sensing and diagnosis platforms, restorative and regenerative biomaterials. Given the beneficial interactions of AgNPs with living structures and their nontoxic effects on healthy human cells, they represent an accurate candidate for various biomedical products. In the present review, the most important and recent applications of AgNPs in biomedical products and biomedicine are considered. Full article
(This article belongs to the Special Issue Nanostructured Materials for Biomedicine and Bioengineering)
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Review
Nanoparticles Engineering by Pulsed Laser Ablation in Liquids: Concepts and Applications
Nanomaterials 2020, 10(11), 2317; https://doi.org/10.3390/nano10112317 - 23 Nov 2020
Cited by 17 | Viewed by 1327
Abstract
Laser synthesis emerges as a suitable technique to produce ligand-free nanoparticles, alloys and functionalized nanomaterials for catalysis, imaging, biomedicine, energy and environmental applications. In the last decade, laser ablation and nanoparticle generation in liquids has proven to be a unique and efficient technique [...] Read more.
Laser synthesis emerges as a suitable technique to produce ligand-free nanoparticles, alloys and functionalized nanomaterials for catalysis, imaging, biomedicine, energy and environmental applications. In the last decade, laser ablation and nanoparticle generation in liquids has proven to be a unique and efficient technique to generate, excite, fragment and conjugate a large variety of nanostructures in a scalable and clean way. In this work, we give an overview on the fundamentals of pulsed laser synthesis of nanocolloids and new information about its scalability towards selected applications. Biomedicine, catalysis and sensing are the application areas mainly discussed in this review, highlighting advantages of laser-synthesized nanoparticles for these types of applications and, once partially resolved, the limitations to the technique for large-scale applications. Full article
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Review
A Review of Carbon Dots Produced from Biomass Wastes
Nanomaterials 2020, 10(11), 2316; https://doi.org/10.3390/nano10112316 - 23 Nov 2020
Cited by 17 | Viewed by 2007
Abstract
The fluorescent carbon dot is a novel type of carbon nanomaterial. In comparison with semiconductor quantum dots and fluorescence organic agents, it possesses significant advantages such as excellent photostability and biocompatibility, low cytotoxicity and easy surface functionalization, which endow it a wide application [...] Read more.
The fluorescent carbon dot is a novel type of carbon nanomaterial. In comparison with semiconductor quantum dots and fluorescence organic agents, it possesses significant advantages such as excellent photostability and biocompatibility, low cytotoxicity and easy surface functionalization, which endow it a wide application prospect in fields of bioimaging, chemical sensing, environmental monitoring, disease diagnosis and photocatalysis as well. Biomass waste is a good choice for the production of carbon dots owing to its abundance, wide availability, eco-friendly nature and a source of low cost renewable raw materials such as cellulose, hemicellulose, lignin, carbohydrates and proteins, etc. This paper reviews the main sources of biomass waste, the feasibility and superiority of adopting biomass waste as a carbon source for the synthesis of carbon dots, the synthetic approaches of carbon dots from biomass waste and their applications. The advantages and deficiencies of carbon dots from biomass waste and the major influencing factors on their photoluminescence characteristics are summarized and discussed. The challenges and perspectives in the synthesis of carbon dots from biomass wastes are also briefly outlined. Full article
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Editorial
Recent Progress in Antimicrobial Nanomaterials
Nanomaterials 2020, 10(11), 2315; https://doi.org/10.3390/nano10112315 - 23 Nov 2020
Cited by 4 | Viewed by 629
Abstract
Bacterial infections are a well-known and serious problem in numerous areas of everyday life, causing death, pain, and huge added costs to healthcare worldwide [...] Full article
(This article belongs to the Special Issue Recent Progress in Antimicrobial Nanomaterials)
Article
Supramolecular Porphyrin Nanostructures Based on Coordination-Driven Self-Assembly and Their Visible Light Catalytic Degradation of Methylene Blue Dye
Nanomaterials 2020, 10(11), 2314; https://doi.org/10.3390/nano10112314 - 22 Nov 2020
Cited by 6 | Viewed by 921
Abstract
A series of porphyrin triads (14), in which each triad is composed of a Sn(IV) porphyrin and two free-base (or Zn(II)) porphyrins, was synthesized and their self-assembled nanostructures were studied. Depending on the substituent on porphyrin moieties, each triad [...] Read more.
A series of porphyrin triads (14), in which each triad is composed of a Sn(IV) porphyrin and two free-base (or Zn(II)) porphyrins, was synthesized and their self-assembled nanostructures were studied. Depending on the substituent on porphyrin moieties, each triad was self-assembled into a different nanostructure. In particular, the cooperative coordination of 3-pyridyl groups in the Sn(IV) porphyrin with the axial Zn(II) porphyrins in triad 4 leads to forming uniform nanofibers with an average width of 10–22 nm. Other triads without the coordinating interaction between the central Sn(IV) porphyrin and the axial porphyrins formed irregularly shaped aggregates in contrast. The morphologies of nanofiber changed drastically upon the addition of pyrrolidine, in which pyrrolidine molecules break down the self-assembly process by coordinating with the axial Zn(II) porphyrins. All porphyrin aggregates exhibited efficient photocatalytic performances on the degradation of methylene blue dye under visible light irradiation. The degradation efficiencies after 2 h were observed to be between 70% and 95% for the aggregates derived from the four triads. Full article
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Article
Electric and Photocatalytic Properties of Graphene Oxide Depending on the Degree of Its Reduction
Nanomaterials 2020, 10(11), 2313; https://doi.org/10.3390/nano10112313 - 22 Nov 2020
Cited by 1 | Viewed by 884
Abstract
When graphene oxide is reduced, the functional groups are released and the structure becomes more ordered. The degree of reduction might be tunable with the process parameters. In our work, graphene oxide is prepared and the effect of thermal and chemical reduction is [...] Read more.
When graphene oxide is reduced, the functional groups are released and the structure becomes more ordered. The degree of reduction might be tunable with the process parameters. In our work, graphene oxide is prepared and the effect of thermal and chemical reduction is investigated. The samples are characterized with TG/DTA-MS, SEM-EDX, TEM, XPS, ATR-FTIR, Raman spectroscopy and XRD. Their electrical resistance, cyclic voltammetry and photocatalytic activity data are investigated. The conductivity can be varied by several orders of magnitude, offering a tool to match its electrical properties to certain applications. Low temperature reduction in air offers a material with the highest capacitance, which might be used in supercapacitors. The bare graphene oxide has considerably larger photocatalytic activity than P25 TiO2. Reduction decreases the activity, meaning that reduced graphene oxide can be used as an electron sink in composite photocatalysts, but does not contribute to the photocatalytic activity by itself. Full article
(This article belongs to the Special Issue Latest Developments in Photocatalytic Materials and Processes)
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Article
A Large-Area and Nanoscale Graphene Oxide Diaphragm-Based Extrinsic Fiber-Optic Fabry–Perot Acoustic Sensor Applied for Partial Discharge Detection in Air
Nanomaterials 2020, 10(11), 2312; https://doi.org/10.3390/nano10112312 - 22 Nov 2020
Cited by 2 | Viewed by 716
Abstract
This article presents an extrinsic fiber-optic acoustic sensor applied for partial discharge (PD) detection in air. A Fabry–Perot (F-P) cavity consisting of a single-mode fiber (SMF) and a graphene oxide (GO) film, whose thickness and effective vibration diameter are approximately 500 nm and [...] Read more.
This article presents an extrinsic fiber-optic acoustic sensor applied for partial discharge (PD) detection in air. A Fabry–Perot (F-P) cavity consisting of a single-mode fiber (SMF) and a graphene oxide (GO) film, whose thickness and effective vibration diameter are approximately 500 nm and 4.377 mm, respectively, is used as this sensing core, and the manufacturing process of GO diaphragms and this sensing probe is illustrated to be simple and controllable. Performance tests indicate that this proposed sensor maintains a linear acoustic-pressure response and a flat frequency response in the range of 200 Hz to 20 kHz, while being an omnidirectional sensor and having high working stability during a ten-day test period. Additionally, PD detection results show that the minimum PD size detected by this proposed sensor in air was approximately 100 pC, which demonstrates that this proposed sensor can achieve high-sensitivity PD detection in air. Full article
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Article
Development of a Bioactive Flowable Resin Composite Containing a Zinc-Doped Phosphate-Based Glass
Nanomaterials 2020, 10(11), 2311; https://doi.org/10.3390/nano10112311 - 22 Nov 2020
Cited by 3 | Viewed by 833
Abstract
Flowable resins used for dental restoration are subject to biofilm formation. Zinc has antibacterial properties. Thus, we prepared a zinc-doped phosphate-based glass (Zn-PBG) to dope a flowable resin and evaluated the antibacterial activity of the composite against Streptococcus mutans (S. mutans) [...] Read more.
Flowable resins used for dental restoration are subject to biofilm formation. Zinc has antibacterial properties. Thus, we prepared a zinc-doped phosphate-based glass (Zn-PBG) to dope a flowable resin and evaluated the antibacterial activity of the composite against Streptococcus mutans (S. mutans) to extrapolate the preventative effect toward secondary caries. The composites were prepared having 0 (control), 1.9, 3.8, and 5.4 wt.% Zn-PBG. The flexural strength, elastic modulus, microhardness, depth of cure, ion release, inhibition zone size, and number of colony-forming units were evaluated and analyzed using ANOVA. The flexural strength of the control was significantly higher than those of Zn-PBG samples (p < 0.05). However, all samples meet the International Standard, ISO 4049. The microhardness was not significantly different for the control group and 1.9 and 3.8 wt.% groups, but the 5.4 wt.% Zn-PBG group had a significantly lower microhardness (p < 0.05). Further, the composite resins increasingly released P, Ca, Na, and Zn ions with an increase in Zn-PBG content (p < 0.05). The colony-forming unit count revealed a significant reduction in S. mutans viability (p < 0.05) with increase in Zn-PBG content. Therefore, the addition of Zn-PBG to flowable composite resins enhances antibacterial activity and could aid the prevention of secondary caries. Full article
(This article belongs to the Special Issue Antibacterial Activity of Nanoparticles)
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Article
Treatment of Breast Cancer-Bearing BALB/c Mice with Magnetic Hyperthermia using Dendrimer Functionalized Iron-Oxide Nanoparticles
Nanomaterials 2020, 10(11), 2310; https://doi.org/10.3390/nano10112310 - 22 Nov 2020
Cited by 16 | Viewed by 1538
Abstract
The development of novel nanoparticles for diagnostic and therapeutic applications has been one of the most crucial challenges in cancer theranostics for the last decades. Herein, we functionalized iron oxide nanoparticles (IONPs) with the fourth generation (G4) of poly amidoamine (PAMAM) [...] Read more.
The development of novel nanoparticles for diagnostic and therapeutic applications has been one of the most crucial challenges in cancer theranostics for the last decades. Herein, we functionalized iron oxide nanoparticles (IONPs) with the fourth generation (G4) of poly amidoamine (PAMAM) dendrimers (G4@IONPs) for magnetic hyperthermia treatment of breast cancer in Bagg albino strain C (BALB/c)mice. The survival of breast cancer cells significantly decreased after incubation with G4@IONPs and exposure to an alternating magnetic field (AMF) due to apoptosis and elevation of Bax (Bcl-2 associated X)/Bcl-2(B-cell lymphoma 2) ratio. After intratumoral injection of G4@IONPs, tumor-bearing BALB/c mice were exposed to AMF for 20 min; this procedure was repeated three times every other day. After the last treatment, tumor size was measured every three days. Histopathological and Immunohistochemical studies were performed on the liver, lung, and tumor tissues in treated and control mice. The results did not show any metastatic cells in the liver and lung tissues in the treatment group, while the control mice tissues contained metastatic breast cancer cells. Furthermore, the findings of the present study showed that magnetic hyperthermia treatment inhibited tumor growth by increasing cancer cell apoptosis, as well as reducing the tumor angiogenesis. Full article
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Article
Barium Titanate (BaTiO3) Nanoparticles Exert Cytotoxicity through Oxidative Stress in Human Lung Carcinoma (A549) Cells
Nanomaterials 2020, 10(11), 2309; https://doi.org/10.3390/nano10112309 - 22 Nov 2020
Cited by 1 | Viewed by 1058
Abstract
Barium titanate (BaTiO3) nanoparticles (BT NPs) have shown exceptional characteristics such as high dielectric constant and suitable ferro-, piezo-, and pyro-electric properties. Thus, BT NPs have shown potential to be applied in various fields including electro-optical devices and biomedicine. However, very [...] Read more.
Barium titanate (BaTiO3) nanoparticles (BT NPs) have shown exceptional characteristics such as high dielectric constant and suitable ferro-, piezo-, and pyro-electric properties. Thus, BT NPs have shown potential to be applied in various fields including electro-optical devices and biomedicine. However, very limited knowledge is available on the interaction of BT NPs with human cells. This work was planned to study the interaction of BT NPs with human lung carcinoma (A549) cells. Results showed that BT NPs decreased cell viability in a dose- and time-dependent manner. Depletion of mitochondrial membrane potential and induction of caspase-3 and -9 enzyme activity were also observed following BT NP exposure. BT NPs further induced oxidative stress indicated by induction of pro-oxidants (reactive oxygen species and hydrogen peroxide) and reduction of antioxidants (glutathione and several antioxidant enzymes). Moreover, BT NP-induced cytotoxicity and oxidative stress were effectively abrogated by N-acetyl-cysteine (an ROS scavenger), suggesting that BT NP-induced cytotoxicity was mediated through oxidative stress. Intriguingly, the underlying mechanism of cytotoxicity of BT NPs was similar to the mode of action of ZnO NPs. At the end, we found that BT NPs did not affect the non-cancerous human lung fibroblasts (IMR-90). Altogether, BT NPs selectively induced cytotoxicity in A549 cells via oxidative stress. This work warrants further research on selective cytotoxicity mechanisms of BT NPs in different types of cancer cells and their normal counterparts. Full article
(This article belongs to the Section Biology and Medicines)
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Editorial
Application of Novel Plasmonic Nanomaterials on SERS
Nanomaterials 2020, 10(11), 2308; https://doi.org/10.3390/nano10112308 - 22 Nov 2020
Viewed by 526
Abstract
During these past two decades, the fabrication of ultrasensitive surface-enhanced Raman scattering (SERS) substrates has explosed by using novel plasmonic materials such bimetallic materials (e [...] Full article
(This article belongs to the Special Issue Application of Novel Plasmonic Nanomaterials on SERS)
Article
Defect Engineering Enhances the Charge Separation of CeO2 Nanorods toward Photocatalytic Methyl Blue Oxidation
Nanomaterials 2020, 10(11), 2307; https://doi.org/10.3390/nano10112307 - 21 Nov 2020
Cited by 2 | Viewed by 761
Abstract
Defect-rich photocatalytic materials with excellent charge transfer properties are very popular. Herein, Sm-doped CeO2 nanorods were annealed in a N2 atmosphere to obtain the defective Sm-doped CeO2 photocatalysts (Vo–Sm–CeO2). The morphology and structure of Vo–Sm–CeO2 were systematically [...] Read more.
Defect-rich photocatalytic materials with excellent charge transfer properties are very popular. Herein, Sm-doped CeO2 nanorods were annealed in a N2 atmosphere to obtain the defective Sm-doped CeO2 photocatalysts (Vo–Sm–CeO2). The morphology and structure of Vo–Sm–CeO2 were systematically characterized. The Vo–Sm–CeO2 nanorods demonstrated an excellent photodegradation performance of methyl blue under visible light irradiation compared to CeO2 nanorods and Sm–CeO2. Reactive oxygen species including OH, ·O2, and h+ were confirmed to play a pivotal role in the removal of pollutants via electron spin resonance spectroscopy. Doping Sm enhances the conductivity of CeO2 nanorods, benefiting photogenerated electrons being removed from the surface reactive sites, resulting in the superior performance. Full article
(This article belongs to the Special Issue Photocatalytic Nanomaterials for Pollutant Remediation)
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Article
Dynamic Behavior of Magnetically Affected Rod-Like Nanostructures with Multiple Defects via Nonlocal-Integral/Differential-Based Models
Nanomaterials 2020, 10(11), 2306; https://doi.org/10.3390/nano10112306 - 21 Nov 2020
Cited by 2 | Viewed by 587
Abstract
Through considering both nonlocality and surface energy effects, this paper suggests suitable mathematical-continuum-based models for free vibration of nanorods with multiple defects acted upon by a bidirectional-transverse magnetic field. By employing both theories of elasticity of Eringen and Gurtin–Murdoch, the equations of motion [...] Read more.
Through considering both nonlocality and surface energy effects, this paper suggests suitable mathematical-continuum-based models for free vibration of nanorods with multiple defects acted upon by a bidirectional-transverse magnetic field. By employing both theories of elasticity of Eringen and Gurtin–Murdoch, the equations of motion for the magnetically affected-damaged rod-like nanostructures are derived using the nonlocal-differential-based and the nonlocal-integral-based models. The local defects are modeled by a set of linearly appropriate axial springs at the interface of appropriately divided nanorods. Through constructing the nonlocal-differential equations of motion for sub-divided portions and by imposing the appropriate interface conditions, the natural frequencies as well as the vibrational modes are explicitly obtained for fixed–free and fixed–fixed nanorods with low numbers of defects. The extracted nonlocal-integral governing equations are also solved for natural frequencies using the finite-element technique. For a particular situation, the model’s results are successfully verified with those of another work. Subsequently, the effects of nonlocality, surface energy, defect’s location, nanorod’s diameter, magnetic field strength, and number of defects on the dominant free vibration response of the magnetically defected nanorods with various end conditions are displayed and discussed. Full article
(This article belongs to the Special Issue Mechanics of Nanostructures and Nanomaterials)
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Article
Making van der Waals Heterostructures Assembly Accessible to Everyone
Nanomaterials 2020, 10(11), 2305; https://doi.org/10.3390/nano10112305 - 21 Nov 2020
Cited by 3 | Viewed by 1315
Abstract
Van-der Waals heterostructures assembled from one or few atomic layer thickness crystals are becoming increasingly more popular in condensed matter physics. These structures are assembled using transfer machines, those are based on mask aligners, probe stations or are home-made. For many laboratories it [...] Read more.
Van-der Waals heterostructures assembled from one or few atomic layer thickness crystals are becoming increasingly more popular in condensed matter physics. These structures are assembled using transfer machines, those are based on mask aligners, probe stations or are home-made. For many laboratories it is vital to build a simple, convenient and universal transfer machine. In this paper we discuss the guiding principles for the design of such a machine, review the existing machines and demonstrate our own construction, that is powerful and fast-in-operation. All components of this machine are extremely cheap and can be easily purchased using common online retail services. Moreover, assembling a heterostructure out of exfoliated commercially available hexagonal boron nitride and tungsten diselenide crystals with a pick-up technique and using the microphotolumenescence spectra, we show well-resolved exciton and trion lines, as a results of disorder suppression in WSe2 monolayer. Our results thus show that technology of the two-dimensional materials and heterostructures becomes accessible to anyone. Full article
(This article belongs to the Special Issue 2D Materials and Their Heterostructures and Superlattices)
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Article
Gas Sensing with Solar Cells: The Case of NH3 Detection through Nanocarbon/Silicon Hybrid Heterojunctions
Nanomaterials 2020, 10(11), 2303; https://doi.org/10.3390/nano10112303 - 21 Nov 2020
Cited by 3 | Viewed by 995
Abstract
Photovoltaic (PV) cells based on single-walled carbon nanotube (SWCNT)/silicon (Si) and multiwalled carbon nanotube (MWCNT)/Si junctions were tested under exposure to NH3 in the 0–21 ppm concentration range. The PV cell parameters remarkably changed upon NH3 exposure, suggesting that these junctions, [...] Read more.
Photovoltaic (PV) cells based on single-walled carbon nanotube (SWCNT)/silicon (Si) and multiwalled carbon nanotube (MWCNT)/Si junctions were tested under exposure to NH3 in the 0–21 ppm concentration range. The PV cell parameters remarkably changed upon NH3 exposure, suggesting that these junctions, while being operated as PV cells, can react to changes in the environment, thereby acting as NH3 gas sensors. Indeed, by choosing the open-circuit voltage, VOC, parameter as read-out, it was found that these cells behaved as gas sensors, operating at room temperature with a response higher than chemiresistors developed on the same layers. The sensitivity was further increased when the whole current–voltage (I–V) curve was collected and the maximum power values were tracked upon NH3 exposure. Full article
(This article belongs to the Special Issue Nanostructured Gas Sensors)
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Article
CXCL12-PLGA/Pluronic Nanoparticle Internalization Abrogates CXCR4-Mediated Cell Migration
Nanomaterials 2020, 10(11), 2304; https://doi.org/10.3390/nano10112304 - 20 Nov 2020
Cited by 2 | Viewed by 855
Abstract
Chemokine-induced chemotaxis mediates physiological and pathological immune cell trafficking, as well as several processes involving cell migration. Among them, the role of CXCL12/CXCR4 signaling in cancer and metastasis is well known, and CXCR4 has been often targeted with small molecule-antagonists or short CXCL12-derived [...] Read more.
Chemokine-induced chemotaxis mediates physiological and pathological immune cell trafficking, as well as several processes involving cell migration. Among them, the role of CXCL12/CXCR4 signaling in cancer and metastasis is well known, and CXCR4 has been often targeted with small molecule-antagonists or short CXCL12-derived peptides to limit the pathological processes of cell migration and invasion. To reduce CXCR4-mediated chemotaxis, we adopted a different approach. We manufactured poly(lactic acid-co-glycolic acid) (PLGA)/Pluronic F127 nanoparticles through microfluidics-assisted nanoprecipitation and functionalized them with streptavidin to docking a biotinylated CXCL12 to be exposed on the nanoparticle surface. Our results show that CXCL12-decorated nanoparticles are non-toxic and do not induce inflammatory cytokine release in THP-1 monocytes cultured in fetal bovine and human serum-supplemented media. The cell internalization of our chemokine receptor-targeting particles increases in accordance with CXCR4 expression in FBS/medium. We demonstrated that CXCL12-decorated nanoparticles do not induce cell migration on their own, but their pre-incubation with THP-1 significantly decreases CXCR4+-cell migration, thereby antagonizing the chemotactic action of CXCL12. The use of biodegradable and immune-compatible chemokine-mimetic nanoparticles to reduce cell migration opens the way to novel antagonists with potential application in cancer treatments and inflammation. Full article
(This article belongs to the Special Issue Immune Responses to Nanomaterials for Biomedical Applications)
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Article
Fabrication of Flexible Multilayer Composite Capacitors Using Inkjet Printing
Nanomaterials 2020, 10(11), 2302; https://doi.org/10.3390/nano10112302 - 20 Nov 2020
Cited by 1 | Viewed by 529
Abstract
This paper shows a straightforward method for printing multilayer composite capacitors with three dielectric layers on flexible substrates. As known from multilayer ceramic chip capacitors (MLCCs), it is possible to create a parallel connection of the layers without enlarging the needed area. Hence, [...] Read more.
This paper shows a straightforward method for printing multilayer composite capacitors with three dielectric layers on flexible substrates. As known from multilayer ceramic chip capacitors (MLCCs), it is possible to create a parallel connection of the layers without enlarging the needed area. Hence, the overall capacitance is increased, as the capacitances of the single dielectric layers add up. To realize printed capacitors, a special ceramic/polymer composite ink is used. The ink consists of surface-modified Ba0.6Sr0.4TiO3 (BST), a polymeric crosslinking agent and a thermal initiator, which allows an immediate polymerization of the ink, leading to very homogenous layers. The dielectric behavior of the capacitors is examined for each completed dielectric layer (via impedance spectroscopy) so that the changes with every following layer can be analyzed. It is demonstrated that the concept works, and capacitors with up to 3420 pF were realized (permittivity of ~40). However, it was also shown that the biggest challenge is the printing of the needed silver electrodes. They show a strong coffee stain effect, leading to thicker edge areas, which are difficult to overprint. Only with the help of printed supporting structures was it possible to lower the failure rate when printing thin dielectric layers. Full article
(This article belongs to the Section Nanocomposite Materials)
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Communication
Biomimetic Nanoparticles Potentiate the Anti-Inflammatory Properties of Dexamethasone and Reduce the Cytokine Storm Syndrome: An Additional Weapon against COVID-19?
Nanomaterials 2020, 10(11), 2301; https://doi.org/10.3390/nano10112301 - 20 Nov 2020
Cited by 4 | Viewed by 2453
Abstract
Recent studies on coronavirus infectious disease 2019 (COVID-19) pathophysiology indicated the cytokine release syndrome induced by the virus as the main cause of mortality. Patients with severe COVID-19 infection present a systemic hyper inflammation that can lead to lung and multi-organ injuries. Among [...] Read more.
Recent studies on coronavirus infectious disease 2019 (COVID-19) pathophysiology indicated the cytokine release syndrome induced by the virus as the main cause of mortality. Patients with severe COVID-19 infection present a systemic hyper inflammation that can lead to lung and multi-organ injuries. Among the most recent treatments, corticosteroids have been identified to be effective in mitigating these catastrophic effects. Our group has recently developed leukocyte-derived nanovesicles, termed leukosomes, able to target in vivo the inflamed vasculature associated with pathological conditions including cancer, cardiovascular diseases, and sepsis. Herein, to gain insights on the anti-inflammatory properties of leukosomes, we investigated their ability to reduce uncontrolled inflammation in a lethal model of lipopolysaccharide (LPS)-induced endotoxemia, recapitulating the cytokine storm syndrome observed in COVID-19 infection after encapsulating dexamethasone. Treated animals showed a significant survival advantage and an improved immune response resolution, as demonstrated by a cytokine array analysis of pro- and anti-inflammatory cytokines, chemokines, and other immune-relevant markers. Our results showed that leukosomes enhance the therapeutic activity of dexamethasone and better control the inflammatory response compared to the free drug. Such an approach could be useful for the development of personalized therapies in the treatment of hyperinflammation related to infectious diseases, including the ones caused by COVID-19. Full article
(This article belongs to the Special Issue Nanomedicine and Biomimetic Drug Delivery Systems)
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Article
Microwave-Assisted Synthesis of Chalcopyrite/Silver Phosphate Composites with Enhanced Degradation of Rhodamine B under Photo-Fenton Process
Nanomaterials 2020, 10(11), 2300; https://doi.org/10.3390/nano10112300 - 20 Nov 2020
Viewed by 625
Abstract
A new composite by coupling chalcopyrite (CuFeS2) with silver phosphate (Ag3PO4) (CuFeS2/Ag3PO4) was proposed by using a cyclic microwave heating method. The prepared composites were characterized by scanning and transmission electron [...] Read more.
A new composite by coupling chalcopyrite (CuFeS2) with silver phosphate (Ag3PO4) (CuFeS2/Ag3PO4) was proposed by using a cyclic microwave heating method. The prepared composites were characterized by scanning and transmission electron microscopy and X-ray diffraction, Fourier-transform infrared, UV–Vis diffuse reflectance spectroscopy, and X-ray photoelectron spectroscopy. Under optimum conditions and 2.5 W irradiation (wavelength length > 420 nm, power density = 0.38 Wcm−2), 96% of rhodamine B (RhB) was degraded by CuFeS2/Ag3PO4 within a 1 min photo-Fenton reaction, better than the performance of Ag3PO4 (25% degradation within 10 min), CuFeS2 (87.7% degradation within 1 min), and mechanically mixed CuFeS2/Ag3PO4 catalyst. RhB degradation mainly depended on the amount of hydroxyl radicals generated from the Fenton reaction. The degradation mechanism of CuFeS2/Ag3PO4 from the photo-Fenton reaction was deduced using a free radical trapping experiment, the chemical reaction of coumarin, and photocurrent and luminescence response. The incorporation of CuFeS2 in Ag3PO4 enhanced the charge separation of Ag3PO4 and reduced Ag3PO4 photocorrosion as the photogenerated electrons on Ag3PO4 were transferred to regenerate Cu2+/Fe3+ ions produced from the Fenton reaction to Cu+/Fe2+ ions, thus simultaneously maintaining the CuFeS2 intact. This demonstrates the synergistic effect on material stability. However, hydroxyl radicals were produced by both the photogenerated holes of Ag3PO4 and the Fenton reaction of CuFeS2 as another synergistic effect in catalysis. Notably, the degradation performance and the reusability of CuFeS2/Ag3PO4 were promoted. The practical applications of this new material were demonstrated from the effective performance of CuFeS2/Ag3PO4 composites in degrading various dyestuffs (90–98.9% degradation within 10 min) and dyes in environmental water samples (tap water, river water, pond water, seawater, treated wastewater) through enhanced the Fenton reaction under sunlight irradiation. Full article
(This article belongs to the Special Issue Application of Nanomaterials in Photocatalysis)
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Article
Studies on Carrier Recombination in GaN/AlN Quantum Dots in Nanowires with a Core–Shell Structure
Nanomaterials 2020, 10(11), 2299; https://doi.org/10.3390/nano10112299 - 20 Nov 2020
Viewed by 635
Abstract
GaN quantum dots embedded in nanowires have attracted much attention due to their superior optical properties. However, due to the large surface-to-volume ratio of the nanowire, the impacts of surface states are the primary issue responsible for the degradation of internal quantum efficiency [...] Read more.
GaN quantum dots embedded in nanowires have attracted much attention due to their superior optical properties. However, due to the large surface-to-volume ratio of the nanowire, the impacts of surface states are the primary issue responsible for the degradation of internal quantum efficiency (IQE) in heterostructured dot-in-nanowires. In this paper, we investigate the carrier recombination mechanism of GaN/AlN dot-in-nanowires with an in situ grown AlN shell structure. Ultraviolet photoelectron spectroscopy (UPS) measurements were performed to describe the band bending effect on samples with different shell thicknesses. Temperature-dependent photoluminescence (TDPL) data support that increasing the AlN shell thickness is an efficient way to improve internal quantum efficiency. Detailed carrier dynamics was analyzed and combined with time-resolved photoluminescence (TRPL). The experimental data are consistent with our physical model that the AlN shell can effectively flatten the band bending near the surface and isolate the surface non-radiative recombination center. Our systematic research on GaN/AlN quantum dots in nanowires with a core–shell structure may significantly advance the development of a broad range of nanowire-based optoelectronic devices. Full article
(This article belongs to the Section Synthesis, Interfaces and Nanostructures)
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Article
Optimized Preparation of Nanosized Hollow SSZ-13 Molecular Sieves with Ultrasonic Assistance
Nanomaterials 2020, 10(11), 2298; https://doi.org/10.3390/nano10112298 - 20 Nov 2020
Cited by 1 | Viewed by 578
Abstract
Because of its unique eight-membered ring pore structure and the arrangement of cations in its structure, the SSZ-13 molecular sieve has a higher affinity for CO2 than other gases, meaning it has attracted more attention than other porous materials for CO2 [...] Read more.
Because of its unique eight-membered ring pore structure and the arrangement of cations in its structure, the SSZ-13 molecular sieve has a higher affinity for CO2 than other gases, meaning it has attracted more attention than other porous materials for CO2 adsorption. However, the expensive template and long preparation time limits the industrial production of SSZ-13. In this work, a hollow structure was successfully introduced into the nanosized SSZ-13 molecular sieve with ultrasonic treatment. The effects of the amount of seed added and the ultrasonic time on the structure were investigated. When the amount of seed added was 0.5 wt.% and the ultrasonic time was 60 min, the sample showed a hollow cubic crystal with a diameter of about 50 nm. The specific surface area reached 791.50 m2/g, and the mesoporous ratio was 66.3%. The samples were tested for CO2 adsorption performance at 298 K. It was found that the hollow sample prepared in this work has higher CO2 adsorption capacity compared with the SSZ-13 zeolite prepared with conventional methods. When the adsorption pressure was 0.27 bar, the adsorption amount reached 2.53 mmol/g. The hollow SSZ-13 molecular sieve reached a CO2 adsorption capacity of 4.24 mmol/g at 1 bar. Full article
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Article
Manganese Ferrite Nanoparticles (MnFe2O4): Size Dependence for Hyperthermia and Negative/Positive Contrast Enhancement in MRI
Nanomaterials 2020, 10(11), 2297; https://doi.org/10.3390/nano10112297 - 20 Nov 2020
Cited by 6 | Viewed by 1303
Abstract
We synthesized manganese ferrite (MnFe2O4) nanoparticles of different sizes by varying pH during chemical co-precipitation procedure and modified their surfaces with polysaccharide chitosan (CS) to investigate characteristics of hyperthermia and magnetic resonance imaging (MRI). Structural features were analyzed by [...] Read more.
We synthesized manganese ferrite (MnFe2O4) nanoparticles of different sizes by varying pH during chemical co-precipitation procedure and modified their surfaces with polysaccharide chitosan (CS) to investigate characteristics of hyperthermia and magnetic resonance imaging (MRI). Structural features were analyzed by X-ray diffraction (XRD), high-resolution transmission electron microscopy (TEM), selected area diffraction (SAED) patterns, and Mössbauer spectroscopy to confirm the formation of superparamagnetic MnFe2O4 nanoparticles with a size range of 5–15 nm for pH of 9–12. The hydrodynamic sizes of nanoparticles were less than 250 nm with a polydispersity index of 0.3, whereas the zeta potentials were higher than 30 mV to ensure electrostatic repulsion for stable colloidal suspension. MRI properties at 7T demonstrated that transverse relaxation (T2) doubled as the size of CS-coated MnFe2O4 nanoparticles tripled in vitro. However, longitudinal relaxation (T1) was strongest for the smallest CS-coated MnFe2O4 nanoparticles, as revealed by in vivo positive contrast MRI angiography. Cytotoxicity assay on HeLa cells showed CS-coated MnFe2O4 nanoparticles is viable regardless of ambient pH, whereas hyperthermia studies revealed that both the maximum temperature and specific loss power obtained by alternating magnetic field exposure depended on nanoparticle size and concentration. Overall, these results reveal the exciting potential of CS-coated MnFe2O4 nanoparticles in MRI and hyperthermia studies for biomedical research. Full article
(This article belongs to the Special Issue Nanotechnologies and Nanomaterials: Selected Papers from CCMR)
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Article
Preparation of Monodispersed Cs0.33WO3 Nanocrystals by Mist Chemical Vapor Deposition for Near-Infrared Shielding Application
Nanomaterials 2020, 10(11), 2295; https://doi.org/10.3390/nano10112295 - 20 Nov 2020
Cited by 3 | Viewed by 643
Abstract
In this study, single-phase Cs0.33WO3 nanocrystals were synthesized by a novel mist chemical vapor deposition method. As prepared, Cs0.33WO3 nanocrystals exhibited a microsphere-like appearance constructed with angular crystal grains with an average size of about 30–40 nm. [...] Read more.
In this study, single-phase Cs0.33WO3 nanocrystals were synthesized by a novel mist chemical vapor deposition method. As prepared, Cs0.33WO3 nanocrystals exhibited a microsphere-like appearance constructed with angular crystal grains with an average size of about 30–40 nm. Characterization by X-ray photoelectron spectroscopy indicated that Cs0.33WO3 nanocrystals consisted of mixed chemical valence states of tungsten ions W6+ and W5+, inducing many free electrons, which could scatter and absorb near-infrared (NIR) photons by plasmon resonance. These Cs0.33WO3 microspheres consisted of a loose structure that could be crushed to nanoscale particles and was easily applied for producing long-term stable ink after milling. Herein, a Cs0.33WO3/polymer composite was successfully fabricated via the ultrasonic spray coating method using mixed Cs0.33WO3 ink and polyurethane acrylate solution. The composite coatings exhibited excellent IR shielding properties. Remarkably, only 0.9 mg cm−2 Cs0.33WO3 could shield more than 70% of NIR, while still maintaining the visible light transmittance higher than 75%. Actual measurement results indicate that it has really good heat insulation properties and shows good prospect in heat insulation window applications. Full article
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Article
Highly Efficient Antimicrobial Activity of CuxFeyOz Nanoparticles against Important Human Pathogens
Nanomaterials 2020, 10(11), 2294; https://doi.org/10.3390/nano10112294 - 20 Nov 2020
Cited by 1 | Viewed by 831
Abstract
The development of innovative antimicrobial materials is crucial in thwarting infectious diseases caused by microbes, as drug-resistant pathogens are increasing in both number and capacity to detoxify the antimicrobial drugs used today. An ideal antimicrobial material should inhibit a wide variety of bacteria [...] Read more.
The development of innovative antimicrobial materials is crucial in thwarting infectious diseases caused by microbes, as drug-resistant pathogens are increasing in both number and capacity to detoxify the antimicrobial drugs used today. An ideal antimicrobial material should inhibit a wide variety of bacteria in a short period of time, be less or not toxic to normal cells, and the fabrication or synthesis process should be cheap and easy. We report a one-step microwave-assisted hydrothermal synthesis of mixed composite CuxFeyOz (Fe2O3/Cu2O/CuO/CuFe2O) nanoparticles (NPs) as an excellent antimicrobial material. The 1 mg/mL CuxFeyOz NPs with the composition 36% CuFeO2, 28% Cu2O and 36% Fe2O3 have a general antimicrobial activity greater than 5 log reduction within 4 h against nine important human pathogenic bacteria (including drug-resistant bacteria as well as Gram-positive and Gram-negative strains). For example, they induced a >9 log reduction in Escherichia coli B viability after 15 min of incubation, and an ~8 log reduction in multidrug-resistant Klebsiella pneumoniae after 4 h incubation. Cytotoxicity tests against mouse fibroblast cells showed about 74% viability when exposed to 1 mg/mL CuxFeyOz NPs for 24 h, compared to the 20% viability for 1 mg/mL pure Cu2O NPs synthesized by the same method. These results show that the CuxFeyOz composite NPs are a highly efficient, low-toxicity and cheap antimicrobial material that has promising potential for applications in medical and food safety. Full article
(This article belongs to the Special Issue Nanomaterials for Biomedical Applications)
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Article
An OMV-Based Nanovaccine Confers Safety and Protection against Pathogenic Escherichia coli via Both Humoral and Predominantly Th1 Immune Responses in Poultry
Nanomaterials 2020, 10(11), 2293; https://doi.org/10.3390/nano10112293 - 20 Nov 2020
Cited by 2 | Viewed by 711
Abstract
Avian pathogenic Escherichia coli (APEC) infection in poultry causes enormous economic losses and public health risks. Bacterial outer membrane vesicles (OMVs) and nano-sized proteolipids enriched with various immunogenic molecules have gained extensive interest as novel nanovaccines against bacterial infections. In this study, after [...] Read more.
Avian pathogenic Escherichia coli (APEC) infection in poultry causes enormous economic losses and public health risks. Bacterial outer membrane vesicles (OMVs) and nano-sized proteolipids enriched with various immunogenic molecules have gained extensive interest as novel nanovaccines against bacterial infections. In this study, after the preparation of APEC O2-derived OMVs (APEC_OMVs) using the ultracentrifugation method and characterization of them using electron microscopy and nanoparticle tracking analyses, we examined the safety and vaccination effect of APEC_OMVs in broiler chicks and investigated the underlying immunological mechanism of protection. The results showed that APEC_OMVs had membrane-enclosed structures with an average diameter of 89 nm. Vaccination with 50 μg of APEC_OMVs had no side effects and efficiently protected chicks against homologous infection. APEC_OMVs could be effectively taken up by chicken macrophages and activated innate immune responses in macrophages in vitro. APEC_OMV vaccination significantly improved activities of serum non-specific immune factors, enhanced the specific antibody response and promoted the proliferation of splenic and peripheral blood lymphocytes in response to mitogen. Furthermore, APEC_OMVs also elicited a predominantly IFN-γ-mediated Th1 response in splenic lymphocytes. Our data revealed the involvement of both non-specific immune responses and specific antibody and cytokine responses in the APEC_OMV-mediated protection, providing broader knowledge for the development of multivalent APEC_OMV-based nanovaccine with high safety and efficacy in the future. Full article
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