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Porcine epidemic diarrhea virus (PEDV) is a highly infectious pathogen with a high mortality rate, which poses a serious threat to newborn piglets. A rapid, safe and effective vaccine is necessary for protecting pigs from PED infection. Nanoparticles have become molecular scaffolds for displaying soluble antigens due to their unique physical and chemical properties. Here, a vaccine candidate was based on the display of PEDV S1 protein on a mi3 nanoparticle platform using SpyTag/SpyCatcher technology. The size, zeta potential and microstructure of the S1-mi3 NPs were investigated, and their effects on the uptake of antigen-presenting cells (APCs) and maturation of dendritic cells (DCs) were analyzed. Mice were immunized via muscular and intranasal administrations, and the levels of humoral, cellular and mucosal immune responses were analyzed. As a result, S1 proteins were surface-displayed on NPs successfully, which self-assembled into nanoparticles composed of 60 subunits and showed superior safety and stability. In addition, mi3 NPs promoted antigen internalization and dendritic cell (DCs) maturation. In the mouse model, S1-mi3 NPs significantly increased the PEDV-specific antibody including serum IgG, secretory IgA (SIgA) and neutralizing antibodies (NAb). Furthermore, S1-mi3 NPs elicited more CD3 + CD4 + and CD3 + CD8 + T cell and cellular immune-related cytokines (IFN-γ and IL-4) compared to monomeric S1. In particular, it can induce an effective germinal center-specific (GC) B cell response, which is closely related to the production of neutralizing antibodies. Overall, S1-mi3 NPs are a promising subunit vaccine candidate against PEDV, and this self-assembly NPs also provide an attractive platform for improving vaccine efficacy against emerging pathogens., Competing Interests: Declaration of Competing Interest All the authors involved in the article declare no conflict of interest., (Copyright © 2024. Published by Elsevier B.V.)

From modular vaccine production to protein assembly on nanoparticles, the SpyCatcher/SpyTag system provides a convenient plug-and-display procedure. Here, we established a general-purpose immunoaffinity chromatography (IAC) method for SpyTagged proteins (Spy&IAC). SpyTags are displayed on the surface of nanoparticles to induce high-affinity monoclonal antibodies, allowing the specific capture of the target protein. Taking the key core antigenic regions of two coronaviruses that are currently more threatened in the field of human and animal diseases, the nucleocapsid (N) protein of SARS-CoV-2 and the COE protein of porcine epidemic diarrhea virus (PEDV) as model proteins, a purification model with SpyTag at the N-terminal or C-terminal expressed in E. coli or mammalian cells was constructed. After the efficient elution of Spy&IAC, the final yield of several proteins is about 3.5-15 mg/L culture, and the protein purity is above 90 %. Purification also preserves the assembly function and immunogenicity of the protein to support subsequent modular assembly and immunization programs. This strategy provides a general tool for the efficient purification of SpyTagged proteins from different expression sources and different tag positions, enabling the production of modular vaccines at lower cost and in a shorter time, which will prepare the public health field for potential pandemic threats., Competing Interests: Declaration of competing interest A patent is being filed for this work (China Patent Application No. 202210827934.7 and No. 202210827939.X)., (Copyright © 2022 Elsevier B.V. All rights reserved.)

A novel hyaluronic acid (HA)-modified hybrid nanocomplex HA-SeSe-COOH/siR-93C@PAMAM, which could efficiently deliver siRNA into tumor cells via a redox-mediated intracellular disassembly, was constructed for enhanced antitumor efficacy. Thereinto, siR-93C (siRNA) and positive PAMAM were firstly mixed into the electrostatic nano-intermediate, and then diselenide bond (-SeSe-)-modified HA was coved to shield excessive positive charges. This hybrid nanocomplex displayed uniform dynamic sizes, high stability, controlled zeta potential and narrow PDI distribution. Moreover, the -SeSe- linkage displayed GSH/ROS dual responsive properties, improving intracellular trafficking of siRNA. In vitro assays in A549 cell line presented that HA-SeSe-COOH/siR-93C@PAMAM has low cytotoxicity, rapid lysosomal escape and significant transfection efficiency; besides, an efficient proliferation inhibition ability and enhanced apoptosis. Furthermore, in animal studies, this negative-surfaced hybrid nanocomplex showed a prolonged circulation in blood and improved inhibition of tumor growth. All these results verified our hypothesis in this study that diselenide bonds-modified HA could promote not only stability and safety of nanoparticles in vivo but also intracellular behavior of siRNA via redox-dual sensitive properties; furthermore, this hybrid nanocomplex provided a visible potential approach for siRNA delivery in the antitumor field.

This study aimed to analyze the effect of the deep learning algorithm on ultrasound elastography on the treatment of cervical cancer with clustered regularly interspaced short palindromic repeats (CRISPR) short hairpin ribonucleic acid (shRNA) nanoparticles, aiming to provide a reference for the clinical application of deep learning to analyze the therapeutic effect of the disease. In this study, CRISPR and shRNA plasmid nanoparticle drugs were used to treat 55 patients with cervical cancer in the experimental group, and normal saline was injected to another 53 patients in the control group, so compare the effect of nanoparticles in the treatment of cervical cancer. Professional doctors and the recurrent neural network (RNN) intelligent algorithm were used to score cervical cancer based on the ultrasound elastograph images by taking blue, green, and red (BGR) as diagnosis criteria. As a result, the experimental group had a total of 217 points before drug administration and a total of 224 points after drug administration. Each patient had an average increase of 0.13 points. The control group had a total of 200 points before drug administration and a total of 223 points after drug administration, and each patient had an average increase of 0.43 points. The experimental group was obviously different from the control group ( P < 0.05). Each tissue image output by the RNN was clearer than the original image, and the score given by intelligent calculation was faster than that of professional doctors. The monitoring effect of the deep learning RNN intelligent algorithm on the therapeutic effect of nanomedicine was analyzed. It was found that the average accuracy of the experimental group and the control group was 98.95% and 90.34%, respectively; and the experimental group was greatly different from the control group ( P < 0.05). In short, nano-CRISPR and shRNA drugs had remarkable effects on the treatment of cervical cancer, and the scores given by the deep learning intelligent algorithm were faster and more accurate, which provided theoretical guidance for the clinical application of deep learning algorithms to analyze the treatment effects of diseases., Competing Interests: The authors declare that they have no conflicts of interest., (Copyright © 2021 Minghui Li et al.)

microRNA-mediated direct cardiac reprogramming, directly converts fibroblasts into induced cardiomyocyte-like cells (iCMs), which holds great promise in cardiac regeneration therapy. However, effective approaches to deliver therapeutic microRNA into cardiac fibroblasts (CFs) to induce in vivo cardiac reprogramming remain to be explored. Herein, a non-viral biomimetic system to directly reprogram CFs for cardiac regeneration after myocardial injury was developed by coating FH peptide-modified neutrophil-mimicking membranes on mesoporous silicon nanoparticles (MSNs) loaded with microRNA1, 133, 208, and 499 (miR Combo). Through utilizing the natural inflammation-homing ability of neutrophil membrane protein and FH peptide's high affinity to tenascin-C (TN-C) produced by CFs, this nanoparticle could realize sequential targeting to CFs in the injured heart and precise intracellular delivery of miRCombo, which induced reprogramming resident CFs into iCMs. In a mouse model of myocardial ischemia/reperfusion injury, intravenous injection of the nanoparticles successfully delivered miRCombo into fibroblasts and led to efficient reprogramming, resulting in improved cardiac function and attenuated fibrosis. This delivery system is minimally invasive and bio-safe, providing a proof-of-concept for biomimetic and sequential targeting nanomedicine delivery system for microRNA-mediated reprogramming therapy in multiple diseases., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Diabetic nephropathy (DN) is a frequent and severe microvascular complication associated with oxidative stress of diabetes mellitus. A novel astaxanthin-based natural antioxidant nanosystem, namely AST-GLU-LIP, with preferential renal uptake and bioavailability were prepared and applied for treatment of diabetic nephropathy in rats. Our results of kidney-targeted evaluation showed that glucose-PEG 600 -DSPE ligand modified AST liposomes could be specifically transported by overexpressed GLUT1 on the membrane of glomerular mesangial cells and achieved excellent kidney-targeted drug delivery. In addition, the results of pharmacodynamics and therapeutics in DN rats demonstrated that AST-GLU-LIP could improve the bioavailability and antioxidant capacity of AST to scavenge redundant ROS induced by oxidative stress. AST-GLU-LIP could also significantly improve the renal pathological morphology to protect the kidney as a therapeutic drug for diabetic nephropathy., (Copyright © 2020. Published by Elsevier B.V.)

The study on the safety of nanomaterials in eyes is still in its early stages. In this study, we put our focus on the effect of one important nanoparticle feature - large surface area - to assess eye safety. To this end, mesoporous silica nanoparticles (MSiNPs) were for the first time employed as a model to evaluate their toxicity in eyes. The porosity of the MSiNPs endows them with a large surface area and the ability to attach to surrounding chemical or biological molecules, further enhancing their surface reactivity and toxic effects. Therefore, to better mimic MSiNP exposure in real environments, we also introduced other hazardous substances such as silver ions (Ag+) to the system and then investigated their synergistic nanotoxicity. Our results showed that the exposure to MSiNPs-Ag+ and even Ag+ at a safe dose, resulted in more significant toxicity than the MSiNPs alone, as evidenced from cell viability, apoptosis, reactive oxygen species (ROS) production, and DNA damage experiments. RNA-Sequencing analysis revealed that the mRNA surveillance signalling pathway plays a unique role in regulating MSiNPs-Ag+-induced cytotoxicity. Besides this, severe corneal damage and dry eye were observed in rat models upon exposure to MSiNPs-Ag+ compared to MSiNPs. Most importantly, we also proposed a protein corona-based therapy to treat MSiNP-induced corneal disease, where the corneal damage could be rescued by fetal bovine serum (FBS) treatment.

Zedoary turmeric oil (ZTO) has a strong antitumor activity. However, its volatility, insolubility, low bioavailability, and difficulty of medication owing to oily liquid limit its clinical applications. Solid lipid nanoparticles can provide hydrophobic environment to dissolve hydrophobic drug and solidify the oily active composition to decrease the volatility and facilitate the medication. Chitosan has been widely used in pharmaceutics in recent years and coating with chitosan further enhances the internalization of particles by cells due to charge attract. Here, Chitosan (CS)-coated solid lipid nanoparticles (SLN) loaded with ZTO was prepared and characterized using dynamic laser scanner (DLS) and transmission electron microscope (TEM). The uptake and distribution of drug were evaluated in vitro and in vivo. The average sizes of ZTO-SLN and CS-ZTO-SLN were 134.3 ± 3.42 nm and 210.7 ± 4.59 nm, respectively. CS coating inverted the surface charge of particles from -8.93 ± 1.92 mV to +9.12 ± 2.03 mV. The liver accumulation of CS-ZTO-SLN was higher than ZTO-SLN (chitosan-uncoated particles) by analysis of tissue homogenate using HPLC, and the bioavailability of ZTO was also obviously improved. The results suggested that SLN coated with CS improved the features of ZTO formulation and efficiently deliver drug to the liver., Competing Interests: Declaration of competing interest The authors declare that there is no conflict of interest regarding the publication of this paper., (Copyright © 2020. Published by Elsevier B.V.)

Trace anionic dyes in wastewater are difficult to be rapidly and efficiently removed because they are completely soluble and poorly biodegradable. Herein, a facile and environmentally friendly adsorbent was fabricated via the surface functioned SiO 2 with abundant amine groups of polyethyleneimine (PEI). The structural characterization indicated that PEI was successfully immobilized on the SiO 2 surface. The adsorption performance of SiO 2 -PEI was evaluated using acid orange II (AOII) as model pollutant. The adsorption of AOII on SiO 2 -PEI displayed high removal rates in the pH range of 2.0-9.0, and exhibited ultrafast removal (99.1% removal rate at 10 min). The adsorption behavior fitted well with the Langmuir isotherm and pseudo-second-order kinetic model, and the maximum uptake capability of AOII was higher than 705.3 mg/g. The excellent adsorption capacity of AOII on SiO 2 -PEI mainly relied on the electrostatic attraction between the sulfonic acid group of AOII and amine group of PEI in the adsorption process. Additionally, other anionic dyes like acid fuchsin and direct sky blue 5B could also be fast and efficiently removed by SiO 2 -PEI. This work is expected to open new possibilities for the ultrafast removal of anionic dye pollutants., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Nature-inspired nanoparticles, from pathogens to mammalian cells, have attracted increasing attention, for their specific functions and unparalled features that are often desired in designing drug/gene delivery nonviral vectors. However, the applications of nonviral vectors are still suffering from the limits of low drug loading efficiency and/or low gene transfection efficiency. Herein, a novel carrier-free nanodrug-based virus-surface-mimicking gene delivery nanosystem is designed by condensing doxorubicin nanoparticles (DNPs) onto the surface of the PEI/DNA nanocomplex through electrostatic force, which would prolong the blood circulation time of PEI/DNA and confer high drug loading characteristics to the PEI/DNA nanosystem. Meanwhile, the gene transfection efficiency of DNA can also be enhanced for the increased roughness of coated DNPs. The in vitro and in vivo results demonstrate that carrier-free nanodrug-based gene delivery nanosystems with high drug loading efficiency (97.5%) as well as a rough surface can enhance the endocytosis of the nanoparticles, and consequently enhance the chemo/gene co-therapy of cancers. This is the first time soft materials are used to design virus-surface-mimicking nanocarriers, avoiding the side effects of inorganic materials caused by their non-degradable property. Importantly, our delicate design opens a new pathway to develop nature-inspired nanoparticles for cancer synergistic therapy.

Cell membrane-camouflaged nanoparticles for cancer therapy have received a burgeoning interest over the past years. However, the low drug loading and intratumoral release efficiency, and lack of precise targeting remains a big challenge; in addition, foreign carriers used may pose an expected burden in the course of metabolism. In this study, we designed and fabricated a novel NIR-responsive highly targeted carrier-free nanosystem by coating the exactly identical source of cracked cancer cell membranes (CCCMs) specifically derived from the homologous tumors onto the surface of the co-assembly nanoparticles of doxorubicin (DOX) and FDA-approved photothermal agent, indocyanine green (ICG). The nanosystems exhibited a high drug loading capacity (89.8%), cancer cell self-recognized ability and immune escape function. Further, the nanodrugs could be efficiently released for the membrane disturbance triggered by photothermal effect of ICG under NIR irradiation. The tumor-bearing mice model demonstrated that the self-carried DOX NPs@ICG@CCCM nanoparticles possessed a strong synergistic chemo-/photothermal therapeutic efficacy against tumors in vivo. The present strategy could be developed as a universal approach for designing and constructing carrier-free theranostic nanovehicles by intentionally selecting specific cancer cell membrane and the inner loading cargoes., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

The efficacious delivery of drugs to the heart is an important treatment strategy for various heart diseases. Nanocarriers have shown increasing promise in targeted drug delivery systems. The success of nanocarriers for delivering drugs to therapeutic sites in the heart mainly depends on specific target sites, appropriate drug delivery carriers and effective targeting ligands. Successful targeted drug delivery suggests the specific deposition of a drug in the heart with minimal effects on other organs after administration. This review discusses the pathological manifestations, pathogenesis, therapeutic limitations and new therapeutic advances in various heart diseases. In particular, we summarize the recent advances in heart-targeted nanoscale drug delivery systems, including dendrimers, liposomes, polymer-drug conjugates, microparticles, nanostents, nanoparticles, micelles and microbubbles. Current clinical trials, the commercial market and future perspective are further discussed in the conclusions.

Nanoparticles containing DNA complexed with the cationic polymer polyethylenimine are efficient vehicles to transduce DNA into cells and organisms. DNA/polyethylenimine nanoparticles (DNPs) also elicit rapid and systemic release of proinflammatory cytokines that promote antitumor immunity. In this study, we report that DNPs possess previously unrecognized immunomodulatory attributes due to rapid upregulation of IDO enzyme activity in lymphoid tissues of mice. IDO induction in response to DNP treatment caused dendritic cells and regulatory T cells (Tregs) to acquire potent regulatory phenotypes. As expected, DNP treatment stimulated rapid increase in serum levels of IFN type I (IFN-αβ) and II (IFN-γ), which are both potent IDO inducers. IDO-mediated Treg activation was dependent on IFN type I receptor signaling, whereas IFN-γ receptor signaling was not essential for this response. Moreover, systemic IFN-γ release was caused by TLR9-dependent activation of NK cells, whereas TLR9 signaling was not required for IFN-αβ release. Accordingly, DNPs lacking immunostimulatory TLR9 ligands in DNA stimulated IFN-αβ production, induced IDO, and promoted regulatory outcomes, but did not stimulate potentially toxic, systemic release of IFN-γ. DNP treatment to induce IDO and activate Tregs blocked Ag-specific T cell responses elicited in vivo following immunization and suppressed joint pathology in a model of immune-mediated arthritis. Thus, DNPs lacking TLR9 ligands may be safe and effective reagents to protect healthy tissues from immune-mediated destruction in clinical hyperimmune syndromes.

Background: The COVID-19 pandemic is a persistent global threat to public health. As for the emerging variants of SARS-CoV-2, it is necessary to develop vaccines that can induce broader immune responses, particularly vaccines with weak cellular immunity. Methods: In this study, we generated a double-layered N-S1 protein nanoparticle (N-S1 PNp) that was formed by desolvating N protein into a protein nanoparticle as the core and crosslinking S1 protein onto the core surface against SARS-CoV-2. Results: Vaccination with N-S1 PNp elicited robust humoral and vigorous cellular immune responses specific to SARS-CoV-2 in mice. Compared to soluble protein groups, the N-S1 PNp induced a higher level of humoral response, as evidenced by the ability of S1-specific antibodies to block hACE2 receptor binding and neutralize pseudovirus. Critically, N-S1 PNp induced Th1-biased, long-lasting, and cross-neutralizing antibodies, which neutralized the variants of SARS-CoV-2 with minimal loss of activity. N-S1 PNp induced strong responses of CD4+ and CD8+ T cells, mDCs, Tfh cells, and GCs B cells in spleens. Conclusions: These results demonstrate that N-S1 PNp vaccination is a practical approach for promoting protection, which has the potential to counteract the waning immune responses against SARS-CoV-2 variants and confer broad efficacy against future new variants. This study provides a new idea for the design of next-generation SARS-CoV-2 vaccines based on the B and T cells response coordination. [ABSTRACT FROM AUTHOR]

Photocatalysis is considered as an effective technique for mitigating ecological risks posed by residual tetracycline (TC). To improve the efficiency of this technique, it is necessary to enable photocatalysts to produce highly reactive species, such as singlet oxygen (1O2). However, due to the high activation energy of 1O2, photocatalysts can hardly produce 1O2 without assistance from external oxidants. Herein, we find that the size-reduced α-Fe2O3 nanoparticles (∼ 4 nm) that anchored on g-C3N4 nanotube (α-Fe2O3@CNNT) can spontaneously generate 1O2 for degradation of TC. In comparison, only hydroxyl radical (·OH) can be produced by g-C3N4 nanotube loaded with ∼ 14 nm α-Fe2O3 nanoparticles (α-Fe2O3/CNNT). Owing to the high reactivity of the 1O2 species, the photocatalytic degradation rate (Kapp) of TC with α-Fe2O3@CNNT (0.056 min−1) was 1.8 times higher than that of α-Fe2O3/CNNT. The experimental results and theoretical calculations suggested that reducing the size of α-Fe2O3 nanoparticles anchored on g-C3N4 nanotube decreased the surface electron density of α-Fe2O3, which induces the generation of high-valent Fe(IV) active sites over α-Fe2O3@CNNT and turns the degradation pathway into a unique 1O2 dominated process. This study provides a new insight on the generation of 1O2 for effective degradation of environmental pollutant. [ABSTRACT FROM AUTHOR]

Porcine Epidemic diarrhea virus (PEDV), which can result in severe vomiting, diarrhea, dehydration and death in newborn piglets, poses a great threat to the pig industry around the world. The S1 subunit of S protein is crucial for triggering neutralizing antibodies binding to the receptor. Based on the advantages of high immunogenicity and precise assembly of nanoparticles, the mi3 nanoparticles and truncated S1 protein were assembled by the SpyTag/SpyCatcher system and then expressed in HEK293F cells, whereafter high-efficiency monoclonal antibodies (mAbs) were produced and identified. The obtained five mAbs can bind to various genotypes of PEDV, including a mAb (12G) which can neutralize G1 and G2 genotypes of PEDV in vitro. By further identification of monoclonal antibody target sequences, 507FNDHSF512 and 553LFYNVTNSYG562 were first identified as B-cell linear epitopes, in which 553LFYNVTNSYG562 was a neutralizing epitope. Alanine scans identified the key amino acid sites of two epitopes. Moreover, the results of multiple sequence alignment analysis showed that these two epitopes were highly conserved in various subtype variants. In brief, these findings can serve as a basis for additional research of PEDV and prospective resources for the creation of later detection and diagnostic techniques. • Highly immunogenic S1 protein nanoparticle was produced. • High-titer mAbs induced by S1 protein nanoparticle were generated, and a mAb 12G can neutralize G1 and G2 genotypes of PEDV in vitro. • 507FNDHSF512 and 553LFYNVTNSYG562 were first identified as B-cell linear epitopese, and the key amino acid sites were identified. [ABSTRACT FROM AUTHOR]

A novel N H TiO 2 photocatalyst was prepared via hydrothermal synthesis followed by a thermal treatment in NH 3 and H 2 atmospheres. The results showed that benzene with the initial concentration of 150 ppm (±5 ppm) could be thoroughly removed by N H TiO 2 under visible light irradiation. The influences of doping and hydrogenation on properties of TiO 2 samples were investigated. It is suggested that the disordered surface layer introduced by hydrogenation contributes to the excellent photocatalytic activity of N H TiO 2 . The synergistic effect of N doping and surface oxygen vacancies was also confirmed by ultraviolet–visible diffuse reflectance spectra and photoluminescence. Moreover, the diverse role of oxygen vacancies in different positions of TiO 2 has been focused on. [ABSTRACT FROM AUTHOR]

Optimizing the surface texture of silicon wafer to improve the light trapping performance and effective carrier lifetime of silicon surface is an efficient and low-cost way to enhance the energy conversion efficiency of mono-crystalline silicon PERC solar cells. In this paper, a simple method was adopted to prepare inverted pyramids with different sizes by varying the ρ value (ρ = [HF]/([HF]+[H 2 O 2 ]) of Cu metal assisted chemical etching (Cu-MACE) etching solution. The chemical mechanism of formation, etching rate, surface reflectivity, and effective minority carrier lifetime mapping of different silicon surface structures were systematically investigated. Moreover, the solar energy absorption rate of these different surface structures were studied by the finite difference time domain (FDTD) method. The results show that when the ρ value was between 25% and 90%, the etching rate of Cu nanoparticles increases with increasing ρ value. The final results reveal that the surface reflectivity, effective minority carrier lifetime and the light absorption were optimal when ρ∼75%, and the uniformity of corresponding inverted pyramid texture is the best. By utilizing the best inverted pyramid texture, the highest efficiency is 22.69%, corresponding Voc is 680.42 mV, Jsc is 41.20 mA/cm2, and FF is 80.94% on the 156.75 × 156.75 mm2 for large area mono-crystalline silicon PERC solar cell. • The optimized inverted pyramid structure were obtained. • The efficiency of such mono-Si PERC solar cells reached 22.68%. • The weighted average reflectance can be as low as 5.45%. • Various inverted pyramid structures prepared by a simple method. • FDTD solution were performed to evaluate the light absorption of different structural parameters. [ABSTRACT FROM AUTHOR]

Abstract: The composite of hollow glass microspheres coated by SnO2 nanoparticles has been successfully fabricated via sol-gel method. The phase structures, morphologies, particle size, shell thickness, chemical compositions of the composite have been characterized by XRD, FESEM, and EDX. The results show that SnO2 coating on hollow glass microspheres can be achieved, and the coating layers are constituted by SnO2 nanoparticles of mean size ca. 15 nm. The SnO2 coating layers grow thicker with the increased concentration of SnCl4. The effects of parameters (reaction temperature, concentration of NaOH and SnCl4, and time) were investigated to yield SnO2 coating on hollow glass microspheres, and the UV–vis absorption spectra of the composites were studied. [Copyright &y& Elsevier]

Abstract: Magnetite (Fe3O4) nanoparticles have been successfully synthesized by sol–gel method combined with annealing under vacuum. The phase structures, morphologies, particle sizes, chemical composition, and magnetic properties of Fe3O4 nanoparticles have been characterized by X-ray diffraction, field emission scanning electron microscopy, energy-dispersive X-ray spectrometer and vibrating sample magnetometer (VSM). The results indicate that the size, the corresponding saturation magnetization value and coercivity value of Fe3O4 nanoparticles increase with the increase of synthesized temperature. And the phase transformation of Fe3O4 nanoparticles has been studied under different atmospheres and temperatures. [Copyright &y& Elsevier]

Abstract: The silica nanolayer with different thickness was coated on the spherical cobalt nanoparticles (an average diameter of 67nm) to form core–shell structure by the controlled hydrolysis and condensation of tetraethyl orthosilicate (TEOS). This coating process was based on the use of silane coupling agent 3-mercaptopropyltrimethoxysilane (HS-(CH2)3Si(OCH3)3, MPTS) as a primer to render the cobalt surface vitreophilic, thus rendering cobalt surface compatible with silica. The control over the silica coating layer thickness can be achieved by varying the reaction time. The cobalt nanoparticles and the cobalt coated with silica shell were confirmed by transmission electron microscopy (TEM). X-ray photoelectron spectroscopy (XPS) was used to gain insight into the way in which the MPTS is bound to the surface of the cobalt nanoparticles. Result of the thermogravimetric analysis (TGA) and differential thermal analysis (DTA) indicate that the thermal stability of cobalt/silica is better than that of pure cobalt nanoparticles. Magnetic properties of these powders have been evaluated. These cobalt/silica core–shell nanoparticles can be utilized as precursors for making property-tunable magnetic nanoparticles, thin films, and multilayered core–shell structure nanocomposites. [Copyright &y& Elsevier]

Abstract: Carbon fibers have been successfully coated with Fe3O4 nanoparticles coating layers via sol–gel method combined with annealing under vacuum. The phase structures and morphologies of the composite have been characterized by XRD and FESEM. The results show that a complete and uniform Fe3O4 nanoparticles coating on carbon fibers can be obtained in the temperature range of 300–550°C. The coating layers with thickness ca. 800nm are composed by Fe3O4 nanoparticles of mean sizes ca. 30nm. The surface properties of Fe3O4 nanoparticles detached from carbon fibers/Fe3O4 composite have been analyzed by XPS and FTIR. [Copyright &y& Elsevier]

Abstract: W/WS2 inorganic fullerene-like (IF) nanoparticles with core–shell structure are synthesized by the reaction of tungsten nanospheres and sulfur at relatively low temperatures (380–600°C) under hydrogen atmosphere, in which tungsten nanospheres were prepared by wire electrical explosion method. Images of transmission electron microscopy and high-resolution transmission electron microscopy show that the composite particles are of core–shell structure with spherical shape and the shell thickness is about 10nm. X-ray powder diffraction results indicate that the interlayer spacing of IF-WS2 shell decreases and approaches that of 2H-WS2 with increasing annealing temperatures, representing an expansion of 3.3–1.6%. A mechanism of IF-WS2 formation via sulfur diffusion into fullerene nanoparticles is discussed. Thermal analysis shows that the nanoparticles obtained at different temperatures exhibit similar thermal stability and the onset temperature of oxidization is about 410°C. Encapsulating hard tungsten core into IF-WS2 and the spherical shape of the core–shell structures may enhance their performance in tribological applications. [Copyright &y& Elsevier]

Abstract: SiO2-coated martensite stainless steel nanoparticles were prepared using wire electrical explosion technique combined with sol–gel technique, and their structural and magnetic properties were studied. The coating silica on stainless steel nanoparticles was based on the use of silane coupling agent 3-mercaptopropyltrimethoxysilane (HS-(CH2)3Si(OCH3)3, MPTS) as a primer to render the stainless steel surface vitreophilic, thus rendering stainless steel surface compatible with silica. The control over the silica coating layer thickness can be achieved by varying the reaction time. For stainless steel nanoparticles, their saturation and remnant magnetizations decreased upon silica coating, and their saturation magnetizations obviously decreased with increasing the thickness of SiO2 coating layer. These stainless steel/silica core–shell nanoparticles can be utilized as precursors for making property-tunable magnetic nanoparticles, thin films, and multilayered core–shell structure nanocomposites. [Copyright &y& Elsevier]

Abstract: TiO2/CoFe2O4 composite nanoparticles with a core–shell structure have been obtained. The core CoFe2O4 nanoparticles were synthesized via co-precipitation method, and the shell TiO2 nanocrystals were derived via sol–gel technology followed by heat-treatment at 450 °C. The morphology and the crystalline structure of composite nanoparticles were characterized by transmission electron microscopy (TEM) and X-ray diffraction, respectively. The as-prepared composite particles can be utilized as a magnetic photocatalyst, which can be fluidized and recovered by an applied magnetic field enhancing both the separation and mixing efficiency for recyclable fluids. Magnetic properties and photocatalytic activities of these powders have been evaluated. [Copyright &y& Elsevier]

Abstract: The spherical nickel nanoparticles (an average diameter of 75nm) were prepared by wire electrical explosion method, and silica was coated on nickel forming complete coverage by the controlled hydrolysis and condensation of tetraethyl orthosilicate (TEOS). The method was based on the use of silane coupling agent 3-mercaptopropyltrimethoxysilane (HS-(CH2)3Si(OCH3)3, MPTS) as a primer to render the nickel surface vitreophilic, thus rendering nickel surface compatible with silica. The thickness of SiO2 coating layer increases with the increasing reaction time. The nickel nanoparticles and the nickel coated with silica shell were confirmed by transmission electron microscopy (TEM). X-ray photoelectron spectroscopy (XPS) was used to gain insight into the way in which the MPTS is bound to surface of the nickel nanoparticles. Result of the thermogravimetric analysis (TGA) and differential thermal analysis (DTA) indicate that the thermal stability of nickel/silica is better than of pure nickel nanoparticles. Magnetic properties of these powders have been evaluated. These nickel/silica core–shell nanoparticles can be utilized as precursors for making property-tunable magnetic nanoparticles, thin films, and multilayered core–shell structure nanocomposites. [Copyright &y& Elsevier]

Abstract: In this work, 3D SnO2 with a hierarchical structure, which was built by numerous one-dimensional tetragonal prism nanorods, had been firstly synthesized by a facile one-step hydrothermal route at 200°C in the presence of cetyltrimethylammonium bromide (CTAB). The cationic surfactant CTAB played a key role in forming the 3D SnO2 hierarchical structure composed of nanorods. In addition, the novel SnO2 hierarchical structure exhibited good gas-sensing properties. The gas sensor showed good selectivity to ethanol gas. Moreover, a linear dependence of the sensitivity on the ethanol concentration was observed, it suggested that the sensor fabricated by SnO2 hierarchical structures is very suitable to detect ethanol with low concentration. [Copyright &y& Elsevier]