Search

PROteolysis TArgeting Chimeras have received increasing attention due to their capability to induce potent degradation of various disease-related proteins. However, the effective and controlled cytosolic delivery of current small-molecule PROTACs remains a challenge, primarily due to their intrinsic shortcomings, including unfavorable solubility, poor cell permeability, and limited spatiotemporal precision. Here, we develop a near-infrared light-controlled PROTAC delivery device (abbreviated as USDPR) that allows the efficient photoactivation of PROTAC function to achieve enhanced protein degradation. The nanodevice is constructed by encapsulating the commercial BRD4-targeting PROTACs (dBET6) in the hollow cavity of mesoporous silica-coated upconversion nanoparticles, followed by coating a Rose Bengal (RB) photosensitizer conjugated poly-L-lysine (PLL-RB). This composition enables NIR light-activatable generation of cytotoxic reactive oxygen species due to the energy transfer from the UCNPs to PLL-RB, which boosts the endo/lysosomal escape and subsequent cytosolic release of dBET6. We demonstrate that USDPR is capable of effectively degrading BRD4 in a NIR light-controlled manner. This in combination with NIR light-triggered photodynamic therapy enables an enhanced antitumor effect both in vitro and in vivo . This work thus presents a versatile strategy for controlled release of PROTACs and codelivery with photosensitizers using an NIR-responsive nanodevice, providing important insight into the design of effective PROTAC-based combination therapy.

Personal protective masks play critical role in preventing the disease epidemic and resisting pathogenic bacterial infestation. However, large quantities of masks were disposed during COVID-19 epidemic, which caused environmental problem and huge economic burden. Herein, we developed reusable masks with inherent antimicrobial and self-cleaning features under solar irradiation. With spun-bonded nonwoven fabrics (SNF) layer as substrate, copper sulfide@polydopamine nanoparticles are deposited on SNF layer (CuS@PDA NPs -SNF), which presents excellent photocatalytic activity. Under solar irradiation, CuS@PDA NPs produce abundant of singly linear oxygen ( 1 O 2 ), which inactivates pathogenic bacteria with high efficiency over 99%. Interestingly, CuS@PDA NPs -SNF cannot cause high temperature to bring any uncomfortable to the person, which is suitable for human to wear in daily life. Such design effectively protect person from the transmission of viral aerosol. Meanwhile, CuS@PDA NPs -SNF masks are reusable and still maintain robust bactericidal ability after washing. The sunlight-mediated self-sterilization at low temperature endows CuS@PDA NPs -SNF masks as powerful personal protective equipment for daily protection, which also provides an instructive way for reducing the environmental impact., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Sonocatalysis has attracted excellent research attention to eradicate hazardous pollutants from the environment effectively. This work synthesised an organic/inorganic hybrid composite catalyst by coupling Fe 3 O 4 @MIL-100(Fe) (FM) with ZnS nanoparticles using the solvothermal evaporation method. Remarkably, the composite material delivered significantly enhanced sonocatalytic efficiency for removing tetracycline (TC) antibiotics in the presence of H 2 O 2 compared to bare ZnS nanoparticles. By adjusting different parameters such as TC concentration, catalyst dosage and H 2 O 2 amount, the optimized composite (20 %Fe 3 O 4 @MIL-100(Fe)/ZnS) removed 78.25% antibiotic in 20 min at the cost of 1 mL of H 2 O 2 . These much superior activities are attributed to the efficient interface contact, effective charge transfer, accelerated transport capabilities and strong redox potential for the superior acoustic catalytic performance of FM/ZnS composite systems. Based on various characterization, free radical capture experiments and energy band structures, we proposed a mechanism for the sonocatalytic degradation of tetracycline based on S-scheme heterojunctions and Fenton like reactions. This work will provide an important reference for developing ZnS-based nanomaterials to study sonodegradation of pollutants., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Authors. Published by Elsevier B.V. All rights reserved.)

In this study, chitosan nanoparticles (HF-CD NPs) were synthesized by an ionic gelation method using negatively charged carboxymethyl-β-cyclodextrin and positively charged 2-hydroxypropyltrimethyl ammonium chloride chitosan bearing folic acid. The surface morphology of HF-CD NPs was spherical or oval, and they possessed relatively small particle size (192 ± 8 nm) and positive zeta potential (+20 ± 2 mV). Meanwhile, doxorubicin (Dox) was selected as model drug to investigate the prepared nanoparticles' potential to serve as a drug delivery carrier. The drug loading efficiency of drug-loaded nanoparticles (HF-Dox-CD NPs) was 31.25%. In vitro release profiles showed that Dox release of nanoparticles represented a pH-sensitive sustained and controlled release characteristic. At the same time, the antioxidant activity of nanoparticles was measured, and chitosan nanoparticles possessed good antioxidant activity and could inhibit the lipid peroxidation inside the cell and avoid material infection. Notably, CCK-8 assay testified that the nanoparticles were safe drug carriers and significantly enhanced the antitumor activity of Dox. The nanoparticles possessed good antioxidant activity, pH-sensitive sustained controlled release, enhanced antitumor activity, and could be expected to serve as a drug carrier in future with broad application prospects.

Lipid-based nanoparticles (LBNPs) are biocompatible and biodegradable vesicles that are considered to be one of the most efficient drug delivery platforms. Due to the prominent advantages, such as long circulation time, slow drug release, reduced toxicity, high transfection efficiency, and endosomal escape capacity, such synthetic nanoparticles have been widely used for carrying genetic therapeutics, particularly nucleic acids that can be applied in the treatment for various diseases, including congenital diseases, cancers, virus infections, and chronic inflammations. Despite great merits and multiple successful applications, many extracellular and intracellular barriers remain and greatly impair delivery efficacy and therapeutic outcomes. As such, the current state of knowledge and pitfalls regarding the gene delivery and construction of LBNPs will be initially summarized. In order to develop a new generation of LBNPs for improved delivery profiles and therapeutic effects, the modification strategies of LBNPs will be reviewed. On the basis of these developed modifications, the performance of LBNPs as therapeutic nanoplatforms have been greatly improved and extensively applied in immunotherapies, including infectious diseases and cancers. However, the therapeutic applications of LBNPs systems are still limited due to the undesirable endosomal escape, potential aggregation, and the inefficient encapsulation of therapeutics. Herein, we will review and discuss recent advances and remaining challenges in the development of LBNPs for nucleic acid-based immunotherapy.

Conventional tumor chemotherapy is limited by its low therapeutic efficacy and side effects, which severely hold back its further application as a first-line agent in clinic. To improve the cure efficacy of cancer, nanozyme with enzyme-like activity has now been extensively investigated as a new strategy for tumor treatment. Herein, an anti-tumor platform based on manganese oxides (MnO x ) modified poly (lactic-co-glycolic acid) (PLGA)@polydopamine (PDA) nanoparticles (PP-MnO x NPs) as an oxidase mimic was developed. PP-MnO x NPs could not only produce abundant reactive oxygen species to inhibit tumor growth taking advantage of their oxidase-like activity, but also encapsulate and release antitumor drug (artesunate) to function as chemotherapy, achieving remarkable synergistic chemo-catalytic therapeutic effects. As an oxidase mimics, PP-MnO x NPs induced the decrease of mitochondrial membrane potential, down-regulation of Bcl-2, as well as activation of Bax and Caspase-3, demonstrating that the apoptosis triggered by PP-MnO x NPs was mediated via mitochondrial pathways. Importantly, the artesunate in PP-MnO x NPs further promoted this apoptosis. In addition, Mn ions released from PP-MnO x NPs facilitated the tumor-microenvironment-specific T1-weighted magnetic resonance imaging. Taken together, this study well clarifies the antitumor mechanism of artesunate-loaded PP-MnO x NPs and offer a synergistic chemo-catalytic strategy for tumor theranostics., (Copyright © 2021 Elsevier B.V. All rights reserved.)

In our previous work, cationic functionalized chitosan was chemically conjugated with superoxide dismutase (SOD) to yield a unique nanoparticle-like conjugate O-HTCC-SOD that has demonstrated superior potential in treating reactive oxygen species (ROS)-related disorders to SOD. Considering contribution of ROS to pathogenesis of osteoarthritis, O-HTCC-SOD was firstly measured for effect on rat chondrocytes exposure to monoiodoacetate (MIA). O-HTCC-SOD was nontoxic to chondrocytes and had more long-acting and intracellular protection effects on chondrocytes against MIA-induced oxidative damage due to its superior elimination of intracellular ROS to SOD. Pharmacokinetic analysis demonstrated that O-HTCC-conjugated SOD significantly prolonged half-life and residence in rat joint cavity, and improved bioavailability compared with unmodified SOD. Intra-articular injection of O-HTCC-SOD significantly attenuated mechanical allodynia in MIA-induced osteoarthritis rats, dramatically suppressed gross morphological and histological lesions of articular cartilage, and greatly enhanced in vivo antioxidant capacity and anti-inflammatory effect. But native SOD had no obvious therapeutic effects. Consequently, the nanoparticle-like conjugate O-HTCC-SOD of the excellent efficacy resulted from its targeted intracellular ROS clearance capability and improved pharmacokinetic profiles, opening up a novel avenue for disease-modifying osteoarthritis drugs., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Rationale: Structural stability and size controllability are critical issues to semiconducting polymer nanoparticles (SPNs), which currently show great potential for theranostic applications. Methods: Herein, multi-responsive semiconducting polymer semi-interpenetrating nanoparticles (PDPP3T@PNIPAMAA IPNs) with highly stable structure and uniform size have been successfully designed by semi-interpenetrating technique. Results: It is proposed for the first time that PDPP3T@PNIPAMAA IPNs were prepared with "reinforced concrete" particle structure, which is even resistant to organic solvent such as ethanol and THF. By adjusting the polymerization time, the obtained PDPP3T@PNIPAMAA IPNs exhibit uniform and controllable particle size with extremely low polydispersity index (~0.037) at 1 h of reaction time. The presence of pH/light/GSH multi-responsive semi-interpenetrating network in PDPP3T@PNIPAMAA IPNs dramatically increase their drug loading efficiency (92.64%), which is significantly higher than previously reported comparable SPNs-based drug delivery systems. Additionally, PDPP3T@PNIPAMAA-DOX IPNs further provide improved therapeutic efficacy by the combination of chemotherapy and photothermal therapy with controllably regulated release of doxorubicin (DOX). In vitro and in vivo results indicate that PDPP3T@PNIPAMAA-DOX IPNs are able to release drugs at controlled rate by pH/light/GSH regulation and offer PAI-guided chemo/photothermal combined therapy with excellent therapeutic efficacy. Conclusions: The semi-interpenetrating network method may be generally extended for the preparation of a wide range of organic polymer nanoparticles to achieve ultrahigh structural stability, precise particle size controllability and excellent drug loading capacity., Competing Interests: Competing Interests: The authors have declared that no competing interest exists., (© The author(s).)

Nanoparticles (NPs) have enormous potential to improve disease diagnosis and treatment due to their intrinsic electronic, optical, magnetic, mechanical, and physiological properties. To realize their full potential for nanomedicine, NPs must be biocompatible and targetable toward specific biomolecules to ensure selective sensing, imaging, and drug delivery in complex environments such as living cells, tissues, animals, and human bodies. In this Account, we summarize our efforts to impart specific biocompatibility and biorecognition functionality to NPs by developing strategies to integrate inorganic and organic NPs with functional DNA (fDNA), including aptamers, DNAzymes, and aptazymes to create fDNA-NPs. These hybrid NPs take advantage of fDNA's ability to either bind targets or catalyze reactions in the presence of targets selectively and utilize their unique physicochemical properties including small size, low immunogenicity, and ease of synthesis and chemical modification in comparison with other molecules such as antibodies. By integrating inorganic NPs such as gold NPs, quantum dots, and iron oxide nanoparticles with fDNA, we designed stimuli-responsive fDNA-NPs that exhibit target induced assembly and disassembly of NPs, resulting in a variety of colorimetric, fluorescent, and magnetic resonance imaging (MRI)-based sensors for diagnostic of a broad range of analytes. To impart both biocompatibility and selectivity on inorganic NPs for targeted bioimaging, we have demonstrated DNA-mediated surface functionalization, shape-controlled synthesis, and coordinative assembly of such NPs as specific bioprobes. A highlight is provided on the construction of fDNA-based nanoprobes with light-activatable sensing and imaging functions, which provides precise control of recognition properties of fDNA with high spatiotemporal resolution. To explore the potential of organic NPs for biosensing applications, we have developed an enzyme-responsive fDNA-liposome as a universal sensing platform compatible with diverse biological targets as well as different detection methods including fluorescence, MRI, or temperature, making possible point-of-care diagnostics. To expand the application regime of organic NPs, we collaborated with the Zimmerman group to prepare single-chain block copolymer-based NPs and incorporated it with a variety of functions, including monovalent DNA for assembly, tunable surface chemistry for cellular imaging, and coordinative Cu(II) sites for catalyzing intracellular click reactions, demonstrating the potential of using organic NPs to create promising fDNA-NP systems with programmable functionalities. Furthermore, we survey our recent endeavor in integration of cell-specific aptamers with different NPs for targeted drug delivery, showing that introducing stimuli-responsive properties into NPs that target tumor microenvironments would enable safer and more effective therapy for cancers. Finally, current challenges and future perspectives in fDNA-mediated engineering of NPs for biomedical applications are discussed.

A versatile and straightforward strategy for the encapsulation of semiconducting polymer nanoparticles (SPNs) using biocompatible polydopamine (PDA) as both the protection and versatile bioconjugation layer is proposed. In addition to providing stable functionalized SPNs, this approach provides SPNs with a flexible surface for further modification with various functional ligands. In this study, three representative surface modifiers including a small molecule (folic acid, FA), a peptide (cRGD) and a stealth polymer (SH-PEG) were conjugated onto the surface of SPNs. Specifically, PDA encapsulation can reliably form SPNs that are uniform in size (∼65 nm) and facilitate the rapid purification of SPN bioconjugates by centrifugation which is difficult to achieve using traditional methods for preparing SPN bioconjugates. Compared to pristine PSBTBT NPs, the synthesized PSBTBT@PDA NPs simultaneously showed more excellent structural stability, significantly enhanced PA brightness and amplified PTT efficacy. Benefiting from the outstanding PA and PTT performances, it is possible for the PSBTBT@PDA NPs to ablate tumors more effectively compared to PSBTBT NPs. Our study thus demonstrates that the PDA encapsulated SPNs should be a promising theranostic agent for PA imaging and PTT.

Highly stable semiconducting polymer nanoparticles (NPs) (poly(9,9-dioctylfluorenyl-2,7-diyl) (PFO)/ poly(fluorene-2,7-ylenevinylene-co-phenylene) (PFV)-dopamine (DA) NPs) with previously unreported core-shell structure are developed for ratiometric sensing of intracellular pH values. PFO/PFV-DA NPs comprise central polyfluorene (PFO) as donor and PFV as acceptor, in which the donor and acceptor are spatially separated into the central core and nanoparticle shell. Specifically, thick PFV shells can not only significantly minimize the quenching interference of dopamine on the emission of standard reference (PFO), but are also able to maximize its accessibility to pH-sensitive dopamine and lead to sensitive response to pH changes. The resulting core-shell PFO/PFV NPs are structurally and optically stable, which can avoid the photobleaching and leakage of materials issues compared to traditional semiconducting polymer nanoparticles (SPNs)-based fluorescence resonance energy transfer (FRET) systems containing small molecules. Additionally, the designed compact PFO/PFV-DA NPs show quantitative response to the pH values in aqueous media and are capable of mapping intracellular pH fluctuations by ratiometric imaging. This work may open up opportunities for the generalizability of the consistent ratiometric emission intensity strategy based on core-shell structured SPNs nanoprobes for highly sensitive biological sensing., (© 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Nasopharyngeal carcinoma (NPC) is a common epithelial malignancy that occurs in the nasopharynx and it is one of the high incidences of malignant tumors in China. As previous reports, berberine hydrochloride (BH) possesses a repressive effect on the proliferation of various cancer types. But the application of BH was hampered for a long time due to its hydrophobic properties, along with poor stability and bioavailability. In this study, folate acid modified chitosan nanoparticles loaded berberine hydrochloride (BH/FA-CTS NPs) were prepared by the ionic cross-linking technique, the physicochemical properties and the influence of BH/FA-CTS NPs on proliferation, migration and apoptosis in human nasopharyngeal carcinoma CNE-1 cells were studied in vitro and in vivo. Results of scanning electron microscopy (SEM) images showed that BH/FA-CTS NPs were sphere and the diameter was 258.2±9.1 nm. The drug loading and encapsulation efficiency were 8.17±1.12% and 87.73±4.21%, respectively. The drug release kinetics exhibited a slower and sustained release over a period of 48 h. Moreover, results of MTT assay and scratch assay displayed that BH/FA-CTS NPs inhibited proliferation and migration of CNE-1 cells remarkably. BH/FA-CTS NPs promoted apoptosis and necrosis of CNE-1 cells. And BH/FA-CTS NPs displayed distinguished higher tumor inhibition than control group, free BH and BH/CTS NPs in vivo. Therefore, as a nanocomposite, BH/FA-CTS NPs provide a new method and option for the treatment of nasopharyngeal carcinoma patients.

Rare-earth (RE)-doped upconversion nanocrystals (UCNCs) are deemed as the promising candidates of luminescent nanoprobe for biological imaging and labeling. A number of methods have been used for the fabrication of UCNCs, but their assembly into porous architectures with desired size, shape and crystallographic phase remains a long-term challenging task. Here we report a facile, anion-induced hydrothermal oriented-explosive method to simultaneously control size, shape and phase of porous UCNCs. Our results confirmed the anion-induced hydrothermal oriented-explosion porous structure, size and phase transition for the cubic/hexagonal phase of NaLuF4 and NaGdF4 nanocrystals with various sizes and shapes. This general method is very important not only for successfully preparing lanthanide doped porous UCNCs, but also for clarifying the formation process of porous UCNCs in the hydrothermal system. The synthesized UCNCs were used for in vitro and in vivo CT imaging, and could be acted as the potential CT contrast agents.

The clinical application of small interfering RNA (siRNA) has been restricted by their poor intracellular uptake, low serum stability, and inability to target specific cells. During the last several decades, a great deal of effort has been devoted to exploring materials for siRNA delivery. In this study, biodegradable, tumor-targeted, self-assembled peptide nanoparticles consisting of cyclo(Arg-Gly-Asp-d-Phe-Lys)-8-amino-3,6-dioxaoctanoic acid-β-maleimidopropionic acid (hereafter referred to as RPM) were found to be an effective siRNA carrier both in vitro and in vivo. The nanoparticles were characterized based on transmission electron microscopy, circular dichroism spectra, and dynamic light scattering. In vitro analyses showed that the RPM/VEGFR2-siRNA exhibited negligible cytotoxicity and induced effective gene silencing. Delivery of the RPM/VEGFR2 (zebrafish)-siRNA into zebrafish embryos resulted in inhibition of neovascularization. Administration of RPM/VEGFR2 (mouse)-siRNA to tumor-bearing nude mice led to a significant inhibition of tumor growth, a marked reduction of vessels, and a down-regulation of VEGFR2 (messenger RNA and protein) in tumor tissue. Furthermore, the levels of IFN-α, IFN-γ, IL-12, and IL-6 in mouse serum, assayed via enzyme-linked immunosorbent assay, did not indicate any immunogenicity of the RPM/VEGFR2 (mouse)-siRNA in vivo. In conclusion, RPM may provide a safe and effective delivery vector for the clinical application of siRNAs in tumor therapy.

The migration and selective localization of graphene nanoplatelets (GNPs) in a polypropylene/high melt strength polypropylene (PP/HMSPP) blend under elongational and shear forces are studied. The effects of elongational flow upon the elongational rheology, X‐ray diffraction patterns, thermal properties, and mechanical properties are investigated. The results show that the elongational viscosity and melt strength of HMSPP are higher than those of PP under elongational flow, whereby HMSPP shows elongational strain hardening behavior, and the migrating of GNPs from the PP to the HMSPP phase is hindered. As a result, the GNPs are constrained to remain at the interface between the two phases. In addition, the elongational force can exfoliate GNPs more effectively, and the orientation of GNPs along the phase interface will reduce the migration rate of GNPs at the interface, while precisely controlling the location of the GNPs at the phase interface. Thus, more thermal conductivity pathways are constructed and, hence, the thermal conductivity of the PP/HMSPP/GNPs composite prepared under elongational flow is higher than that prepared under shear flow. The present work provides a new method for the preparation of highly thermally conductive polymer composites. [ABSTRACT FROM AUTHOR]

Exfoliation of graphene nanoplatelets (GNP) in polymer melts is one of the key challenges when applying melt mixing for preparing polymer-based composite. And the GNP can be exfoliated better within the polymer matrix under the elongational flow field than under the shear flow field. Here, we design three extrusion dies with different convergent-divergent channels to explore the exfoliation mechanism of GNP in polymer melt under elongational flow. The flow field in the convergent-divergent channels is numerically simulated, and the results demonstrate that elongational flow plays a dominant role in the convergent-divergent channel when compared to shear flow. The exfoliation states of GNP in different channels are assessed by the thickness and interlayer space of GNP using analysis of scanning electron micrographs, transmission electron micrographs, and X-ray diagrams. And a significant enhancement (increased by 103%) in the in-plane thermal conductivity of PP (polypropylene)/GNP composites extruded by the designed convergent-divergent channel further demonstrates the GNP are exfoliated efficiently under the elongational flow. Furthermore, an exfoliation model is used to estimate the required stress and explore the exfoliation mechanism of GNP. And the exfoliation mechanism of GNP is associated with the applied stress and the angle between the applied stress and the normal direction of GNP. This work could provide experimental and theoretical guidance for the preparation of high-performance composite filled with layered nanosheets. [ABSTRACT FROM AUTHOR]

Polydopamine (PDA) has been found to be as functional materials in a wide range of applications. However, the degradation behavior and mechanism of PDA are still in debate. For well understanding the degradation, PDA nanoparticles (PDA NPs) were prepared by oxidation and self-polymerization of dopamine and employed to study the degradation properties. We systematically studied the degradation of PDA NPs by adjusting the pH value, temperature and alkali strength of the system. PDA NPs were more prone to degrade under alkaline conditions above pH 11.0, and the stronger the alkalinity (pH 13.0) induced the faster the degradation rate. The analysis results for the entire degradation process showed that the size of the PDA NPs firstly decreased and then the morphology of PDA NPs changed from spheres to nanosheets with degradation time. After 120 h of degradation, PDA was completely degraded into monomers and oligomers with three or four repeat units that can be soluble in water. Moreover, PDA showed good biocompatibility. This study would give a strong evidence to confirm the degradation of PDA and help for designing the new PDA materials in biomedical and environmental fields. [ABSTRACT FROM AUTHOR]

The tribological performance of carbon-fiber-reinforced polymer (CFRP) incorporated by different content of graphite nanoplatelets (GNPs) was investigated. By high pressure compression molding, the orientation of GNPs in the in-plane direction increases with the increase of GNPs content, which is beneficial to the formation of GNPs tribofilm during the friction. The results of the friction experiment show that reductions were achieved for the friction coefficient (44.7 %) and wear rate (77.8 %) of the CFRP with 15 wt% GNPs. Further, under different friction conditions including different sliding speeds, loads, time, and temperatures, the mechanism of the formation and destruction of the GNPs tribofilm was found to have a significant effect on the friction properties of CFRP. [ABSTRACT FROM AUTHOR]

The preparation and dielectric properties of silver-polydopamine/poly (vinylidene fluoride) (Ag-PDOP/PVDF) composite films with suppressed dielectric loss are reported. The dielectric loss tangents of the composite films were found to be rather low similar to that of pure PVDF over the frequency range 100 Hz to 30 kHz, almost regardless of the Ag content, and even lower than that of pristine PVDF in the relatively high frequency region. The nanoscale structure comprised of Ag nanoparticles (Ag NPs), isolated by the PDOP coating and the PVDF matrix, hindered the formation of percolative networks, resulting in the decreased conduction loss in the composite films, even at a high filler loading. The strong interfacial interaction between the Ag@PDOP particles and the PVDF matrix also contributed to the restrained interfacial loss. Consequently, these composite films had higher permittivity and smaller dielectric loss than the PVDF matrix at relatively high frequencies, and would thus be attractive for physically small capacitor applications in electronics and electric power systems. [ABSTRACT FROM AUTHOR]

[Display omitted] • The introduction of elongational flow enlarges the volume ratio range of the formation of co-continuous structure. • The graphene nanoplatelets are oriented along the phase interface and remain at the interface steadily. • The conductivity of composites prepared under the elongational flow improve significantly compare with shear flow. Controlling the filler selective distribution at the interface of co-continuous polymer blend is an effective way to fabricate high performance composites. In this work, the graphene nanoplatelets (GNPs) were distributed at the interface of co-continuous polypropylene (PP)/polyamides 6(PA6) blend by melt blending under the elongational flow generated by convergent-divergent channels. And the formation of co-continuous structure and migration mechanism of GNPs in the PP/PA6 blend under the elongational flow were discussed based on the analysis of rheological measurement, scanning electron micrographs, selective etching experiment and thermal conductivity measurement. The results show that both PP and PA6 phase are elongated into fibrous phase structure under the elongational flow. This indeed enlarge the volume ratio range of composites forming co-continuous structure. And GNPs are oriented along the phase interface and stay at the interface during migration under the elongational flow, which can improve its in-plane thermal conductivity. The in-plane thermal conductivity of the PP/PA6/GNPs composites prepared under the elongational flow are all higher than those prepared under the shear flow. Particularly, the composite prepared under the elongational flow with the 65/35 vol ratio of PP/PA6 still kept a co-continuous structure and the GNPs distributed at the interface. Its in-plane thermal conductivity reached a maximum value of 1.13 W/m K. [ABSTRACT FROM AUTHOR]

In this paper, we report the development of a facile one-pot hydrothermal method for the controlled synthesis of monodispersed BaGdF5 :Yb/Er nanoparticles for computed tomography ( CT) and magnetic resonance ( MR) imaging. The as-prepared nanoparticles have uniform size with a diameter of 20-25 nm. MTT tests show that the cell viability surpasses 90% even with a concentration of nanoparticles of 500 µg/ mL, suggesting that the as-prepared BaGdF5 :Yb/Er nanoparticles possess low toxicity. For both BaGdF5 :Yb/Er nanoparticles and iopromide, the Hounsfield unit ( HU) values increase with the their concentration. The slope of BaGdF5 :Yb/Er nanoparticles is about 26.47, which is much higher than that of iopromide (16.98), indicating a better CT imaging effect. Interestingly, we find that the synthesized BaGdF5 :Yb/Er nanoparticles exhibit paramagnetism. Our in vitro and in vivo imaging experiments demonstrate that the synthesized monodispersed BaGdF5 :Yb/Er nanoparticles can serve as effective contrast agents for CT and MR imaging. [ABSTRACT FROM AUTHOR]

The effective and locally sustained delivery of hydrophobic drug with hydrogels as carriers is still a challenge owing to the inherent incompatibility of hydrophilic hydrogel network and hydrophobic drug. One promising approach is to use porous hydrogels to encapsulate and deliver hydrophobic drug in the form of nanoparticles to the disease sites. However, this approach is currently limited by the inability to load concentrated hydrophobic drug nanoparticles into the hydrogels because of the severe nanoparticle aggregation during the loading process. In this article, we firstly designed and fabricated efficient drug nanoparticles embedded hydrogels for hydrophobic drug delivery by incorporating monodisperse silybin (hydrophobic drug for liver protection) nanoparticles into acrylated hyaluronic acid (HA-AC) based hydrogels through in situ cross-linking. The silybin nanoparticles embedded hydrogel scaffolds proved to be a good sustained release system with a long period of 36 h. The drug release from this hybrid hydrogels could be modulated by tuning HA-AC concentration, cross-linking ratio, chain length of cross-linker and drug loading amount. The different kinetic models were applied, and it was observed that the release profile of silybin best followed the Hixson-Crowell model for the release of drug from the hydrogels embedding silybin nanoparticles. It could be envisioned that this process would significantly advance the potential applications of hydrogel scaffolds mediated hydrophobic drug delivery in clinical therapies. [ABSTRACT FROM AUTHOR]

Abstract: This work introduces an effective, inexpensive, and large-scale production approach to the synthesis of Fe2O3 nanoparticles with a favorable configuration that 5nm iron oxide domains in diameter assembled into a mesoporous network. The phase structure, morphology, and pore nature were characterized systematically. When used as anode materials for lithium-ion batteries, the mesoporous Fe2O3 nanoparticles exhibit excellent cycling performance (1009mAhg−1 at 100mAg−1 up to 230cycles) and rate capability (reversible charging capacity of 420mAhg−1 at 1000mAg−1 during 230cycles). This research suggests that the mesoporous Fe2O3 nanoparticles could be suitable as a high rate performance anode material for lithium-ion batteries. [Copyright &y& Elsevier]

Abstract: A simple approach is proposed to prepare C-SiO2 composites as anode materials for lithium ion batteries. In this novel approach, nano-sized silica is soaked in sucrose solution and then heat treated at 900°C under nitrogen atmosphere. Transmission electron microscopy (TEM) and X-ray diffraction (XRD) analysis shows that SiO2 is embedded in amorphous carbon matrix. The electrochemical test results indicate that the electrochemical performance of the C-SiO2 composites relates to the SiO2 content of the composite. The C-SiO2 composite with 50.1% SiO2 shows the best reversible lithium storage performance. It delivers an initial discharge capacity of 536mAhg−1 and good cyclability with the capacity of above 500mAhg−1 at 50th cycle. Electrochemical impedance spectra (EIS) indicates that the carbon layer coated on SiO2 particles can diminish interfacial impedance, which leads to its good electrochemical performance. [Copyright &y& Elsevier]

Abstract: Monodispersed amphiphilic FePt nanoparticles with the diameter of about 4nm were synthesized by high temperature pyrolysis of iron(III) acetylacetonate and platinum(II) acetylacetonate. Their amphiphilicity is contributed to the tetraethylene glycol (TEG) and oleic acid (OA) on the surface, which is confirmed by FTIR and XPS spectra. They provide a superparamagnetic property with the saturation magnetization (Ms) of about 25emu/g and the transverse relaxivity (r 2) of about 122.6mM−1 s−1 in aqueous solutions. Furthermore, FePt nanoparticles show low cytotoxicity in living cells. They can be uptaken by HeLa cells effectively and result in the obvious decrease of T 2 relaxation time after internalization. [Copyright &y& Elsevier]

Chitosan nanoparticles have been considered as potential candidates for drug loading/release in drug delivery systems. In this paper, nanoparticles (HACAFNP) loading adriamycin based on 2-hydroxypropyltrimethyl ammonium chloride chitosan grafting folic acid (HACF) were synthesized. The surface morphology of the novel nanoparticles was spherical or oval, and the nanoparticles exhibited a relatively small hydrodynamic diameter (85.6 ± 2.04 nm) and positive zeta potential (+21.06 ± 0.96 mV). The drug release of nanoparticles was assayed and represented a burst effect followed by a long-term steady release. Afterward, the antioxidant efficiencies of nanoparticles were assayed. In particular, the target nanoparticles exhibited significant enhancement in radical scavenging activities. Cytotoxicities against cancer cells (MCF-7, BGC-823, and HEPG-2) were estimated in vitro, and results showed nanoparticles inhibited the growth of cancer cells. It's worth noting that the inhibition index of HACAFNP against BGC-823 cells was 71.19% with the sample concentration of 25 μg/mL, which was much higher than the inhibitory effect of ADM. It was demonstrated that the novel nanoparticles with dramatically enhanced biological activity, reduced cytotoxicity, and steady release could be used as the practical candidates for drug loading/release in a delivery system. [ABSTRACT FROM AUTHOR]

In this study, electrochemiluminescence (ECL) from luminol incorporated ion-selective nanoparticles is observed that enables the analysis of aqueous ions (e.g. calcium ions). Aqueous calcium ions are known to transport into the nanoparticles and bind with the ionophore, which leads to the generation of more luminol anions in the nanoparticles to maintain electric neutrality. The presence of more luminol anions increases the electro-oxidation rate and induces an enhanced ECL intensity. The increase of ECL intensity is observed to be linearly dependent on the calcium concentrations from 1 to 500 μM, supporting the ECL determination of aqueous ions. The successful exhibition of these ECL based ion-selective nanosensors will not only provide a universal strategy for the ion detection, but also offer a new detection mechanism in ion-selective opotodes. [ABSTRACT FROM AUTHOR]

The aim of this study was to overcome drawbacks of the inhomogeneous dispersion and facile agglomeration of nano-ZnO/poly(N-isopropylacrylamide) composite hydrogels (nano-ZnO/PNIPAm composite hydrogels) during synthesis and improve the anti-mold property of the nano-ZnO/PNIPAm composite hydrogels. Here, nano-ZnO/PNIPAm composite hydrogels were prepared by the radical polymerization method. Fourier transform infrared (FTIR) spectroscopy, transmission electron microscopy (TEM), differential scanning calorimeter (DSC), and dynamic light scattering (DLS) were used to characterize the effects of different dispersants on the particle sizes, dispersions, and phase transition characteristics of the nano-ZnO/PNIPAm composite hydrogels. The anti-mold properties of nano-ZnO/PNIPAm composite hydrogels were studied. Results revealed that the nano-ZnO/PNIPAm composite hydrogel prepared by the addition of nano-ZnO dispersion liquid exhibited the smallest particle size, the most homogeneous dispersion, and the highest stability. The addition of the dispersant did not change the phase transition characteristics of nano-ZnO/PNIPAm, and the nano-ZnO/PNIPAm composite hydrogels (Pf) exhibited good anti-mold properties to the bamboo mold. [ABSTRACT FROM AUTHOR]

• Ag-Bi/C film exhibited both adsorptive and catalytic properties. • Ag-Bi/C film was synthesized by immersion-calcination method. • Nanoparticles of Ag and Bi in Ag-Bi/C film were stable, and the film showed excellent renewability. Ag-Bi/C film was synthesized by immersion-calcination method and its efficient performance to remove Rhodamine B (RhB) in aqueous solution was reported in this article. Ag-Bi/C film showed synergistic behaviours of catalytic degradation and adsorption in removing RhB at the room temperature. Ag-Bi/C film could interact with H 2 O 2 to promote the degradation of RhB, and the pseudo-first-order kinetic model fitted best to describe the catalytic oxidation process. Ag-Bi/C film with porous structure also could adsorb RhB, and the adsorption fitted well with the pseudo-second-order kinetic model. Due to the core-shell structure caused by the carbon coating, nanoparticles of Ag and Bi in the film had great stability, which made Ag-Bi/C film have excellent recycling performance. [ABSTRACT FROM AUTHOR]

Abstract: Ca9Co12O28 nanoparticles with size of about 25nm were prepared by Pechini process at 850°C for 4h. The as-obtained nanoparticles demonstrated initial charge/discharge capacities of 908 and 816mAh/g and a stable discharge capacity of 210mAh/g after 50 cycles. Different morphologies of Ca9Co12O28 as multilayer structure and micro-plates were also obtained by solid-state reaction and coprecipitation-precursor technique at 850°C for 20h. When they were studied in the charge/discharge experiments of lithium ion batteries, the initial discharge capacities reached values of 762 and 790mAh/g, together with stable discharge capacities of 141 and 151mAh/g after 50 cycles, respectively, which were both lower than those of nanoparticles. [Copyright &y& Elsevier]

• AuNPs were modified by using acrylamide. • GO nanosheets were modified by using dithiothreitol. • AuNPs@GO nanosheets were fabricated via "click chemistry". • Micropatterned AuNPs@GO nanosheets were manufactured via a predesigned mask. Here, the micropatterned gold nanoparticles (AuNPs) on graphene oxide (GO) nanosheet (AuNPs@GO) was fabricated via thiol-Michael addition click reaction under ultraviolet (UV) light. First, AuNPs and GO were both functionalized by acrylamide and dithiothreitol, respectively, which were characterized by transmission electron microscope (TEM), X-ray photoelectron spectroscopy (XPS), dynamic light scattering (DLS) and ultraviolet–visible spectroscopy (UV–vis). The size of acrylamide modified AuNPs increased to 52.8 ± 16.5 nm compared to bare AuNPs (44.1 ± 14.5 nm). The AuNPs@GO could be fabricated under the UV-light, and the UV–vis signal varied depending on the concentration of AuNPs. Also, the micropatterned structure of AuNPs@GO nanosheet was accomplished by using a designed mask, which showed a high potential for cancer diagnosis and therapy. [ABSTRACT FROM AUTHOR]

[Display omitted] Pelargonic acid vanillylamide (PAVA), a capsaicin-type dacryagogue agent utilized for counter-terrorism and riot control, possesses a low stimulus threshold. This characteristic can lead to environmental contamination following its application and may easily result in secondary stimulation to personnel. Cobalt-doped Ti 3 C 2 -MXene nanosheets (Co 3 O 4 /Ti 3 C 2 @C) were synthesized for the purpose of activating peracetic acid (PAA) and degrading PAVA. A carbon layer was coated on the surface of Ti 3 C 2 -MXene nanosheets to address the challenge of poor oxygen resistance in MXenes, thus preventing a significant decline in surface reactivity. The BET surface area of Co 3 O 4 /Ti 3 C 2 @C was expanded to 149.6 m2/g, significantly exceeding that of Ti 3 C 2 (13.0 m2/g) and Co 3 O 4 (56.4 m2/g). With 0.5 mg/mL of Co 3 O 4 /Ti 3 C 2 @C and 0.35 mM of PAA, 100 mg/L of PAVA was completely degraded within 60 min. The augmented BET surface area and the presence of more active sites confer remarkable PAA activation and catalytic degradation properties toward PAVA. Parameters such as initial pH, PAVA concentration, catalyst dosage, and PAA concentration on PAVA degradation were systematically assessed. Furthermore, the reusability and stability of the nanocomposite were substantiated through recycling tests. Radical quenching experiments and electron paramagnetic resonance analysis demonstrated the acetylperoxy radical (CH 3 CO 3 ) as the primary species responsible for PAVA degradation. This research serves as an illustration of the utilization of MXene and transition metal activated PAA in wastewater treatment. [ABSTRACT FROM AUTHOR]

Herein we described a deoxyribonucleic acid (DNA) calculator for sensitive detection of the determination of adenosine triphosphate (ATP) using gold nanoparticles (GNP) and PicoGreen fluorescence dye as signal transducer, and ATP and single-stranded DNA (DNA-M′) as activators. The calculator-related performances including linearity, reaction time, logic gate, and selectivity were investigated, respectively. The results revealed that this oligonucleotide sensor was highly sensitive and selective. The detection range was 50–500 nmol/L (R2 = 0.99391) and the detection limit was 46.5 nmol/L. The AND DNA calculator was successfully used for the ATP detection in human urine. Compared with other methods, this DNA calculator has the characteristics of being label-free, non-enzymic, simple, and highly sensitive. [ABSTRACT FROM AUTHOR]

Nd 2 Fe 14 C-based magnet is prepared by a mechanochemical method, namely high-energy ball-milling Nd 2 Fe 11 B x (x = 0–0.15) alloy in heptane (C 7 H 16 ), followed by annealing to 850 °C in vacuum. Under the action of high-energy ball-milling, Nd 2 Fe 11 B x react with heptane to form NdH 2+δ , Fe-(CB), C, etc. H 2 is released and Nd 2 Fe 17 , Nd 2 Fe 17 C x (x = 0–3), Nd 2 Fe 14 C, Nd carbides and α-Fe are formed in the subsequent annealing. C amount depends on ball-milling time t . Long time ball milling or high C content suppresses the formation of 2:17 phase and favors the formation of 2:14:1 phase in the final products. Excessive ball-milling results in the quick increase of α-Fe. The maximum of magnetically hard Nd 2 Fe 14 C is obtained at t = 4 h. For Nd 2 Fe 11 samples, there exists considerable quantity of Nd carbides and α-Fe phase appears earlier and increases rapidly with extending the ball-milling time t . The addition of B element shortens the ball-milling time of the formation of maximum Nd 2 Fe 14 C and prominently suppresses the formation of Nd carbide and α-Fe. The optimum magnetic properties, coercivity i H c of 1193.7 kA/m, remanence M r of 580.9 kA/m, maximum magnetic energy product ( BH ) max of 91.7 kJ/m 3 is approaching to its theoretic value of 99.2 kJ/m 3 for isotropic Nd 2 Fe 14 C magnet, are obtained in Nd 2 Fe 11 B 0.06 alloy ball milled for 3.5 h. [ABSTRACT FROM AUTHOR]

The surface modification of Pt/C catalyst with Ag and the electrocatalytic oxidation of ethanol on the Ag–modified Pt/C catalysts are investigated. The Ag–modified Pt/C catalysts are prepared by means of the potentiostatic deposition of Ag on the Pt nanoparticles loaded on carbon black and coated on glassy carbon (GC) electrodes. Instrumental analysis and electrochemical analysis show that the metal nanoparticles are well distributed on carbon black and the surface of the Pt nanoparticles is partially covered by Ag. Cyclic voltammetric (CV) results display that the deposition of Ag leads to a significant improvement in the activity of Pt/C for ethanol oxidation in alkaline solution. In a wide range of Ag loadings, the Ag–modified Pt/C catalysts show more negative onset oxidation potential and much higher peak current density than the Pt/C catalyst, though Ag has no catalytic activity for ethanol oxidation. [ABSTRACT FROM AUTHOR]

Highlights • The Cr 0.4 Pd 0.6 /MIL-101-NH 2 was achieved by impregnation-reduction method. • The Cr 0.4 Pd 0.6 /MIL-101-NH 2 is efficient catalyst for FA dehydrogenation. • NH 2 has an important effect on the formation of ultrafine size nanoparticles. • NH 2 and Cr contribute to the modification of electronic structure of Pd. Abstract Ultrafine and well dispersed CrPd nanoparticles are successfully immobilized on NH 2 -functionalized porous metal-organic framework MIL-101 by a facile sequential impregnation-reduction approach. By virtue of the bimetallic synergistic effect between Cr and Pd and the strong metal-support interaction between CrPd nanoparticles and MIL-101-NH 2 support, the resulting Cr 0.4 Pd 0.6 /MIL-101-NH 2 catalyst exhibits excellent catalytic activity for the generation of hydrogen from formic acid, affording an excellent initial turn over frequency value as high as 2009 mol H 2 mol Pd−1 h−1 at 323 K, which is much higher than most of the reported noble metal heterogeneous catalysts for this catalytic reaction under similar conditions. [ABSTRACT FROM AUTHOR]

[Display omitted] • Exfoliation and distribution behavior for different diameter GNPs in composites during a physical foaming were discussed. • Visualization analysis was used to investigate the effect of saturation pressure on polymer/GNPs composites under scCO 2 treatment. • Molecular dynamics simulations were used to analyze the GNPs exfoliation during a foaming process. The effects of supercritical CO 2 (scCO 2) on polymer chains' mobility and graphene nanoplatelets (GNPs) exfoliation and distribution in a microcellular foaming process are investigated by the molecular dynamics (MD) simulations and experiments. The results of MD simulations and visualization analysis confirm that the synergistic effect of scCO 2 molecules and polystyrene (PS) chains is beneficial for them to penetrate into the interlayer of GNPs during the scCO 2 treatment at high saturation pressure. The scanning electron microscope images show that some cells exist in the interlayer of GNPs in the foam fabricated in the highest saturation pressure and shortest depressurization time. With foaming in different depressurization time, the growing cells facilitate the movement of GNPs after their exfoliation, leading to alignment around the cells. As compared to large diameter GNPs, the GNPs with small diameter rearrange easily and distribute more homogeneously due to lower resistance of GNPs' movement. [ABSTRACT FROM AUTHOR]

Highlights: [•] Graphene-encapsulated Fe2O3 nanorice was fabricated at room temperature. [•] The Fe2O3 nanorice was uniformly wrapped in the graphene sheets. [•] The composite shows higher capacity retention after 500 cycles. [•] The morphology of the Fe2O3 nanorice in the composite was kept after 500 cycles. [Copyright &y& Elsevier]

• In-situ growth method is adopted to prepare the hybrid of ZIF-67 and carbon nanofibers (CNF). • CoN-HPCNF-900 exhibits superior ORR and OER bifunctional catalytic activity. • Superb performance is obtained for CoN-HPCNF-900-based zinc-air battery. Developing highly active and robust bifunctional non-precious oxygen electrocatalysts for oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) is of paramount importance for enhancing the efficiency of zinc-air battery. Herein, Co nanoparticles anchored in N doped hollow and porous carbon nanofibers (CoN-HPCNF) are obtained via an in-situ growth-pyrolysis approach with the hybrid of ZIF-67 and carbon nanofibers as the precursor. Originating from its high surface area, firm and hierarchical porous structure, effective doping of N as well as synergistic effect from Co nanoparticles and HPCNF, the optimized CoN-HPCNF shows prominent bifunctional catalytic activity and long-term stability toward OER and ORR. Importantly, the assembled aqueous zinc-air battery with the prepared catalyst as the air cathode delivers a peak power density of 126.6 mW cm−2 and narrow charge-discharge voltage gap together with excellent operation durability (more than 280 h at the current density of 5 mA cm−2), outdoing the commercial precious metal catalysts (Pt/C + IrO 2). [ABSTRACT FROM AUTHOR]