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Various physiological activities and metabolic reactions of cells need to be carried out under the corresponding pH environment. Intracellular GSH as an acid tripeptide and an important reducing substance also plays an important role in maintaining cellular acid-base balance and redox balance. Therefore, developing a method to monitor pH and GSH and their changes in cells is necessary. Herein, we developed a novel turn-on fluorescent silicon nanoparticles (SiNPs) using N -(2-aminoethyl)-3-aminopropyltrimethoxysilane as the silicon source and dithiothreitol as the reducing agent via a one-pot hydrothermal method. It was worth mentioning that the fluorescence intensity of the SiNPs increased along with the acidity increase, making the SiNPs have excellent pH and GSH sensing capability. Furthermore, the pH and GSH sensing performance of the SiNPs in the cell was verified by confocal imaging and flow cytometry experiment. Based on the above, the prepared SiNPs had the potential to be used as an intracellular pH and GSH multimode fluorescent sensing platform and exhibited the ability to distinguish between normal cells and cancer cells.

Poor tumor specificity is one of the key obstacles for clinical applications of nanotheranostic agents, consequently leading to serious side effects and unsatisfactory therapeutic efficacy. Herein, biomolecule-based nanohybrids (named as Hb-PDA-GOx) with multiple stimuli-responsiveness were designed and fabricated to enhance tumor-specific therapy. The nanohybrids embodied two proteins, i.e., hemoglobin (Hb) and glucose oxidase (GOx), which exhibited cascade catalytic activity selectively within the tumor microenvironment (TME). Specifically, GOx catalyzes the overexpressed glucose into gluconic acid and hydrogen peroxide (H 2 O 2 ), which not only initiated starvation therapy (ST) through cutting off the nutrition supply for carcinoma cells, but also provided H 2 O 2 for sequential Fenton reaction induced by Hb that generating biotoxic hydroxyl radicals (•OH) for chemodynamic therapy (CDT). Moreover, localized heat generation from polydopamine (PDA) in the nanohybrids can implement photothermal therapy (PTT) and reinforce the CDT efficacy. Excitingly, effective eradication of solid tumors and significant suppression of metastatic tumors growth were achieved by utilizing Hb-PDA-GOx as a versatile theranostic agent. All these results had been verified by in vitro and/or in vivo experiments. In light of the superior anticancer effects and insignificant systemic toxicity, the as-fabricated biomolecule-based nanohybrids could be employed as a promising agent for tumor-specific therapy. More importantly, the high biocompatibility and biodegradability of the selected biomolecules would facilitate subsequent clinical translation. STATEMENT OF SIGNIFICANCE: (1) A facile one-pot synthesis strategy was proposed to fabricate biomolecule-based tumor theranostic agent with high biocompatibility and biodegradability, which would facilitate subsequent clinical translation; (2) The as-developed theranostic agent was endowed with multiple stimuli-responsiveness for achieving tumor-specific and cascade-enhanced synergistic therapy; (3) The in vivo experiments demonstrated that the as-developed theranostic agent can not only effectively eradicate solid tumors, but also significantly suppress metastatic tumors growth., 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 © 2022 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.)

A rapid and sensitive fluorescence-based immunochromatographic test (ICT) was successfully developed to determine chloramphenicol (CAP) levels in three food products. In this method, lanthanide fluorescent microspheres were used as a label to detect CAP in food samples within 30 min quantitatively, and the result was displayed on the test strip reader. After optimizing detection conditions, the detection limit (LOD) for the three food products was 0.048-0.073 ng g -1 , and the half-maximal inhibitory concentration (IC 50 ) was 0.27 ng mL -1 . Six other veterinary drugs were detected using the test strip, and no cross-reactivity was observed, indicating that the specificity of the method was satisfactory. This method was also successfully applied to determine CAP in honey, egg, and fish samples, with recoveries ranging from 78.73% to 121.12%. The results demonstrated that this test strip had high sensitivity and specificity, and could be used for field detection within 30 min.

For harmonizing the contradiction of nanotheranostic agents between enhanced tumor accumulation and penetration, efficient cell internalization and fast elimination are key tactics for promoting their clinical applications. Herein, programmed stimuli-responsive poly( N -isopropylacrylamide)-carbon dot (PNIPAM-CD) hybrid nanogels are designed to address the abovementioned conflicts. The enlarged particle size of PNIPAM-CDs enables one to effectively improve their accumulation at tumor sites. Once the hybrid nanogels are docked in tumors and exposed to deep-red-light (660 nm) irradiation, heat and reactive oxygen species (ROS) are generated from the CDs, consequently activating photothermal therapy (PTT) and photodynamic therapy (PDT) effects and meanwhile inducing partial degradation of PNIPAM-CDs for deep tissue penetration. Further, enhanced cellular internalization of the functional components can be achieved owing to the pH-responsive charge reversal and temperature-dependent hydrophilic/hydrophobic conversion characteristics of PNIPAM-CDs. Finally, the overexpressed glutathione (GSH) in tumor cells would trigger further cleavage of the partially degraded hybrid nanogels, which is beneficial for their rapid clearance from the body. This work not only proposed a novel strategy to fabricate nanotheranostic agents using just a single functional component (i.e., the versatile CDs) to simplify the preparation process but also achieved effective delivery of agents into tumor cells by overcoming the multiple biological barriers to enhance therapeutic efficacy and decrease side effects.

Biological application of chiral nanoparticles (NPs) has aroused enormous levels of attention over recent years. Here, we synthesized magneto-chiral cobalt hydroxide (Co(OH) 2 ) NPs that exhibited strong chiroptical and unique magnetic properties and applied these NPs to detect and monitor reactive oxygen species (ROS) in living cells and in vivo . Circular dichroism (CD) and magnetic resonance imaging (MRI) signals of the magneto-chiral Co(OH) 2 NPs exhibited a wide intracellular ROS detection range from 0.673 to 612.971 pmol/10 6 cells with corresponding limits of detection (LOD) at 0.087 and 0.179 pmol/10 6 cells, far below that of currently available probes; the LOD for d-aspartic acid coated Co(OH) 2 NPs (d-Co(OH) 2 NPs) was 5.7 times lower than that for l-aspartic acid coated Co(OH) 2 NPs (l-Co(OH) 2 NPs) based on the CD signals. In addition, d-Co(OH) 2 NPs also exhibited dynamic ROS monitoring ability. The high levels of selectivity and sensitivity to ROS in complex biological environments can be attributed to the Co 2+ oxidation reaction on the surface of the NPs. Furthermore, magneto-chiral Co(OH) 2 NPs were able to quantify the levels of ROS in living mice by fluorescence and MRI signals. Collectively, these results reveal that magneto-chiral Co(OH) 2 NPs exhibit a remarkable ability to quantify ROS levels in living organisms, and could therefore provide new tools for exploring chiral nanomaterials as a potential biosensor to investigate biological events.

In this experiment, Panax notoginseng saponins chitosan nanoparticles(PNS-NPs) were prepared by self-assembly and their appearance, particle size, encapsulation efficiency, drug loading, polydispersity index(PDI), Zeta potential, and microstructure were characterized. The prepared PNS-NPs were intact in structure, with an average particle size of(209±0.258) nm, encapsulation efficiency of 42.34%±0.28%, a drug loading of 37.63%±0.85%, and a Zeta potential of(39.8±3.122) mV. The intestinal absorption of PNS-NPs in rats was further studied. The established HPLC method of PNS was employed to investigate the effects of pH, perfusion rate, and different drugs(PNS raw materials, Xuesaitong Capsules, and PNS-NPs). The absorption rate constant(K_a) and apparent permeability coefficient(P_(app)) in the duodenum, jejunum, ileum, and colon were calculated and analyzed. As illustrated by the results, the intestinal absorption of PNS-NPs was increased in the perfusion solution at pH 6.8(P<0.05), and perfusion rate had no significant effect on the K_a and P_(app) of PNS-NPs. The intestinal absorption of PNS-NPs was significantly different from that of PNS raw materials and Xuesaitong Capsules(P<0.05), and the intestinal absorption of PNS-NPs was significantly improved.

Photodynamic therapy (PDT) is frequently used in cancer treatment in clinical settings. However, its applications in stroma-rich solid tumors, e.g., triple negative breast cancer, are limited by abnormal mechanical microenvironments. Solid stress accumulated in stroma-rich solid tumors compresses tumor blood vessels, hampers the delivery of photosensitizers (PSs) in tumor tissues, and poses a major challenge for potent PDT. Here, we report a novel combination strategy to augment PDT based cancer therapy by combining hydroxyethyl starch-chlorin e6 conjugate self-assembled nanoparticles (HES-Ce6 NPs) with the transforming growth factor-β (TGFβ) inhibitor LY2157299 (LY). HES-Ce6 conjugates, as synthesized by one step esterification reaction, could self-assemble into uniform HES-Ce6 NPs, which exhibited enhanced photostability and generated more reactive oxygen species (ROS) under 660 nm laser irradiation than free Ce6. Prior to PDT, intragastric administration of LY decreased collagen deposition, alleviated solid stress, and decompressed tumor blood vessels. As a result, the reconstructed tumor mechanical microenvironment promoted accumulation and penetration of HES-Ce6 NPs into tumor tissues, contributing to augmented antitumor efficacy of HES-Ce6 NP mediated PDT. Modulating tumor mechanical microenvironments using TGFβ blockade to enhance the delivery of PSs in tumors with excessive extracellular matrix represents an efficient strategy for treating stroma-rich solid tumors.

Early and accurate detection of breast cancer plays an important role in improving the survival rates of patients. In this work, we designed and synthesized the Gal-NAc-imprinted nanoparticles (GIPs) via boronate-affinity glycan-oriented surface imprinting strategy. Molecularly imprinted polymers (MIPs) were hybridized with fluorescent silicon nanoparticles (SiNPs) to target Tn antigens. However, the single fluorescent imaging mode is not conducive to obtaining accurate diagnosis, due to its poor tissue penetration. To resolve this obstacle, doping gadolinium (Gd) into SiNPs was adopted to emerge an extra significant magnetic resonance (MR) signal, achieving highly sensitive fluorescence imaging and magnetic resonance imaging (MRI) with high spatial resolution. GIPs had uniform particle size around 31.8 nm, and exhibited satisfactory fluorescence stability. The maximum adsorption capacity of GIPs was 1.15 μM/g with a high imprinting factor (IF) of 7.5. Confocal laser scanning microscope imaging revealed that the GIPs had excellent specific recognition ability with a low cytotoxicity. GIPs also showed an outstanding MR performance on cancer cells. Therefore, the synthesized nanoparticles had desirable performance in dual-model imaging to specifically target recognition cancer cells. It may have a tremendous potential in real biological samples., (Copyright © 2020 Elsevier B.V. All rights reserved.)

This study compared the effects of five types of inorganic nanoparticles (INPs) on the 17β-estradiol (E2) adsorption to graphene oxide (GO). The results showed that INPs increased the equilibrium time for the adsorption of E2 to GO. Higher Brunauer-Emmett-Teller (BET) surface area of INPs resulted in lower diffusion rate of E2, and thus the adsorption rate constant (k 2 ) calculated from pseudo-second-order kinetic model negatively correlated with the BET surface area of INPs (p = 0.037). In addition, INPs decreased the adsorption amount of E2 to GO, and the inhibition effects declined in the order of Al 2 O 3  > ZnO > TiO 2  > SiO 2  > Fe 2 O 3 . This is determined by the interactions between GO and INPs. The positively charged ZnO and Al 2 O 3 strongly heteroaggregate with GO via electrostatic attraction, and then significantly inhibited E2 adsorption to GO. In contrast, the homoaggregation of GO was superior to its heteroaggregation with negatively charged SiO 2 and TiO 2 , and then lower inhibition of E2 adsorption to GO was induced. Fe 2 O 3 with less negative charge (-8.48 mV) led to the lowest inhibition effect on E2 adsorption to GO because of its preferable homoaggregation. The results were further confirmed by Derjaguin-Landau-Verwey-Overbeek calculation, transmission electron microscopy, and sedimentation experiments. This study revealed how the properties of INPs influence their effects on the adsorption of E2 by GO, and the findings are critical to understand the behavior and fate of GO and pollutants in natural aquatic environment., Competing Interests: Declaration of competing interest None., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Tumor penetration is the bottleneck for current cancer nanomedicine, limiting the ultimate antitumor efficacy in the clinic. Herein, by exploiting the well-known instability of indocyanine green (ICG), we report the preparation of near infrared (NIR) light responsive nanoparticles (NP) for enhanced tumor penetration. ICG crosslinks hydroxyethyl starch (HES) and doxorubicin (DOX) conjugates (HES-SS-DOX) via noncovalent interactions, facilitating the formation of ICG@HES-SS-DOX NP. The light triggered degradation of ICG leads to the dissociation of such NP, and the resulting HES-SS-DOX has been shown to penetrate deeper in both H22 tumor spheroids and tumor bearing mice, due to the photothermal effect of ICG. Therefore, the disintegrable ICG@HES-SS-DOX NP have better tumor penetration capacity than their counterparts, which originally cannot dissociate under NIR light stimulation. The reported ICG@HES-SS-DOX NP might be potent in treating malignant tumors with dense extracellular matrices, such as liver and pancreatic cancers. This study opens up a novel functionality of FDA-approved ICG for cancer nanotherapeutics.

Folic acid (FA) has long been used as a specific targeting agent since many cancer cells overexpress folate receptors (FRs). Herein, novel functionalities of FA will be explored: directed self-assembly of nanoparticles for drug delivery together with pH responsive release. By conjugating with dextran (DEX), DEX-FA exerts a pH dependent self-assembly behavior: it self-associates into nanoparticles (NPs) around physiological pH (pH 7) and disassembles at higher pH (pH > 9). Doxorubicin (DOX), a model antitumor drug, has been successfully encapsulated via electrostatic interactions between DOX and FA. Moreover, the pH responsive release behaviors of DOX are controlled by FA. The DOX@DEX-FA NPs exhibit typical FA-FRs-mediated endocytosis in vitro and targeted delivery in vivo, altogether contributing to an enhanced antitumor efficacy, alleviated side effects, and elongated overall survival in a 4T1 subcutaneous tumor-bearing mouse model. The DOX@DEX-FA NPs have been demonstrated to be a simple, safe and efficient nanoplatform, holding significant translation potential for treating FR-overexpressing cancers. This study may present novel functionalities of FA in cancer-targeted nanotherapeutics.

This study strategically fabricates multifunctional nanopyramids to allow the ultrasensitive quantification of dual microRNAs (miR-203 b and miR-21) in living cells and their responsive bioimaging in vivo. The nanopyramids, composed of Au-Cu 9 S 5 nanoparticles (NPs), upconversion NPs (UCNPs), and Ag 2 S NPs, emit two luminescent signals simultaneously with excitation at 808 nm, arising from the UCNPs at 541 nm in the visible region and from the Ag 2 S NPs at 1227 nm in the second window of near-infrared (NIR-II) region. The upconversion luminescence has a linear relationship with miR-203 b from 0.13 to 54.54 fmol per 10 µg RNA and a limit of detection (LOD) of 0.09 fmol per 10 µg RNA , whereas the Ag 2 S NP luminescence has a linear relationship with miR-21 from 0.37 to 43.56 fmol per 10 µg RNA , with a LOD of 0.23 fmol per 10 µg RNA . Significantly, this study demonstrates that the nanopyramids can be successfully used for miRs-responsive bioimaging in a tumor-bearing animal model. Furthermore, taking advantage of the photothermal capabilities of pyramids, the tumors can also be eliminated completely. These nanopyramids not only overcome the obstacles in the simultaneous detection of multiple miRs at the cellular level but also provide a cancer theranostic platform in vivo., (© 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Tracking transplanted stem cells is necessary to clarify cellular properties and improve transplantation success. In this study, we designed and synthesized melanin-based gadolinium 3+ (Gd 3+ )-chelate nanoparticles (MNP-Gd 3+ ) of ∼7 nm for stem cell tracking in vivo. MNP-Gd 3+ possesses many beneficial properties, such as its high stability and sensitivity, shorter T1 relaxation time, higher cell labeling efficiency, and lower cytotoxicity compared with commercial imaging agents. We found that the T1 relaxivity (r 1 ) of MNP-Gd 3+ was significantly higher than that of Gd-DTPA; the nanoparticles were taken up by bone mesenchymal stem cells (BMSCs) via endocytosis and were broadly distributed in the cytoplasm. Based on an in vitro MTT assay, no cytotoxicity of labeled stem cells was observed for MNP-Gd 3+ concentrations of less than 800 µg/mL. Furthermore, we tracked MNP-Gd 3+ -labeled BMSCs in vivo using 3.0T MRI equipment. After intramuscular injection, MNP-Gd 3+ -labeled BMSCs were detected, even after four weeks, by 3T MRI. We concluded that MNP-Gd 3+ nanoparticles at appropriate concentrations can be used to effectively monitor and track BMSCs in vivo. MNP-Gd 3+ nanoparticles have potential as a new positive MRI contrast agent in clinical applications. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 131-137, 2017., (© 2016 Wiley Periodicals, Inc.)

Silicon nanoparticles (SiNPs) have been reported to be synthesized by microwave-assisted methods under high pressure. However, there is still a lack of knowledge about the synthesis of SiNPs via microwave-assisted methods under normal pressure. Here we developed a new, facile, one-pot microwave-assisted method for the synthesis SiNPs (∼4.2 nm) with excellent water solubility under normal pressure by employing glycerol as the solvent. Furthermore, glycerol might be responsible for the photoluminescence quantum yield (PLQY) value up to 47% for the resultant SiNPs. The use of organic solvent could afford less nanoparticle surface defects compared with those prepared in aqueous solution, thus improving the fluorescent efficiency. The as-prepared SiNPs simultaneously featured bright blue-green fluorescence, long lifetime (∼12.8 ns), obvious up-conversion luminescence originating from two-photon absorption, superbly strong photostability, and favorable low toxicity. As a satisfactory probe, the as-synthesized SiNPs were successfully applied in fluorescence imaging of human cervical carcinoma cell lines (HeLa) and zebrafish.

N-(2-hydroxyl) propyl-3-trimethyl ammonium chitosan chloride (HTCC) is hydro-soluble chitosan (CS) derivative, which can be obtained by the reaction between epoxypropyl trimethyl ammonium chloride (ETA) and CS. The preparation parameters for the synthesis of HTCC were optimized by orthogonal experimental design. ETA was successfully grafted into the free amino group of CS. Grafting of ETA with CS had great effect on the crystal structure of HTCC, which was confirmed by the XRD results. HTCC displayed higher capability to form nanoparticles by crosslinking with negatively charged sodium tripolyphosphate (TPP). Ribavrin- (RIV-) loaded HTCC nanoparticles were positively charged and were spherical in shape with average particle size of 200 nm. More efficient drug encapsulation efficiency and loading capacity were obtained for HTCC in comparison with CS, however, HTCC nanoparticles displayed faster release rate due to its hydro-soluble properties. The results suggest that HTCC is a promising CS derivative for the encapsulation of hydrophilic drugs in obtaining sustained release of drugs.

Stereoselective catalysis is common in living systems mediated by natural nanoenzymes. However, few artificial nanomaterials are developed for enantioselective and stereoselective catalysis. In this study, AgxCdyS‐AgCd nanoparticles (NPs) with specific heterojunctions, strong chiral optical activities, and excellent enantioselective catalytic ability are constructed. Similar to photosensitive enzymes, AgxCdyS‐AgCd NPs stabilized with l‐/d‐penicillamine (l‐/d‐AgxCdyS‐AgCd NPs) can serve as photocatalysts, which show the highest catalytic efficiency toward the photodegradation of methyl blue compared with that of Ag2S and CdS NPs and lead to 50% enhancement of photoconversion efficiency of Cr6+ to Cr3+ as well. Moreover, attributed to the higher chiral preference between l‐AgxCdyS‐AgCd NPs and l‐Tartaric acid (l‐TA), d‐AgxCdyS‐AgCd NPs and d‐Tartaric acid (d‐TA), the photoreduction efficiency of Cr6+ to Cr3+ mediated by l‐AgxCdyS‐AgCd NPs with l‐TA, and d‐AgxCdyS‐AgCd NPs with d‐TA samples is enhanced as high as 30% compared with the samples of l‐AgxCdyS‐AgCd NPs with d‐TA, and d‐AgxCdyS‐AgCd NPs with L‐TA. This study establishes a versatile way to construct enantioselective inorganic catalysts for biocatalysis, biomedicine, and other applications. [ABSTRACT FROM AUTHOR]

Hydrogen (H 2) generation from formic acid (FA) decomposition is a promising route in practical application of hydrogen energy. As a promising H 2 supplier, besides the advantage of high H 2 content and excellent stability, FA can also be used as a mild reducing agent. Herein, an in-situ prepared NiAuPd nanoparticles (NPs) supported on amine-functionalized carbon nanotubes (NiAuPd/NH 2 -CNTs) with FA as the reducing agent is successfully developed at room temperature. The as-prepared NiAuPd/NH 2 -CNTs are directly used for the catalytic decomposition of FA, exhibiting excellent activity and 100% H 2 selectivity with the initial turnover frequency (TOF initial) value of 699.1 and 3006.1 mol H 2 mol Pd-1 h-1 at 303 and 333 K, respectively. Moreover, the additive sodium formate (SF) can further facilitate the reduction process and enhance the catalytic performance, with the TOF initial value of 4391.1 mol H 2 mol Pd-1 h-1 at 333 K, which are comparable to most of the reported heterogeneous catalysts with the complicated post-treatment. The excellent catalytic performance of NiAuPd/NH 2 -CNTs is mainly attributed to the high dispersion of NPs and the boost effect of -NH 2 group on O–H cleavage. This work provides a feasible strategy to design in-situ prepared catalysts for the efficient high-quality H 2 generation from FA for fuel cells application. [Display omitted] • NiAuPd/NH 2 -CNTs is successfully synthesized via a simple in-situ reduction method. • NiAuPd/NH 2 -CNTs shows excellent catalytic performance for FA dehydrogenation. • CA and –NH 2 group play key roles in modifying the formation and growth of metal NPs. • Synergistic effect between Ni, Au and Pd can improve the catalytic performance. [ABSTRACT FROM AUTHOR]

In the present study, chiral CuxCoyS nanoparticles (NPs) were developed to selectively induce apoptosis of senescent cells using both an alternating magnetic field (AMF) and near infrared (NIR) photon illumination. The chiral effects on living cells were investigated, and d‐CuxCoyS NPs showed about 2.5 times higher of internalized ability than l‐NPs. By modifying beta 2 macroglobulin (MG), senescent cells were effectively eliminated by d‐CuxCoyS NPs without damaging the activities of normal cells under AMF and photon illumination. Compared to the individual application of NIR illumination and AMF, their synergistic effect induced the production of caspase‐3 with a much shorter treatment time and higher efficiency due to the more serious photon‐induced cellular redox and mechanical damage of cellular skeleton. Moreover, the developed strategy was successfully used to remove senescent cells in vivo. This study developed a controllable way of regulating cell activities using chiral NPs, which will provide a valuable way for treating diseases and promoting health. [ABSTRACT FROM AUTHOR]

MgO nanomaterial (nano-MgO) is a promising candidate in the antibacterial field owing to its high stability, environmental/ecological safety, good biocompatibility, and broad-spectrum antibacterial activity. However, the practical application of MgO nanoparticles is primarily limited by their relatively low antibacterial activity. In the present work, the fabrication of lithium (Li)-doped magnesium oxide (MgO) nanoparticles via a simple, low-cost solution combustion method is reported, and the effect of fuel type of citric acid, urea, and glycine as fuels on the microstructure and antibacterial properties of Li-doped MgO nanoparticles is systematically investigated. X-ray diffraction (XRD) analysis demonstrates that the Li-doped MgO has a cubic structure. Field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) analyses reveal that the Li-doped MgO synthesized using citric acid as the fuel exhibits a uniformly distributed spherical morphology along with the smallest crystallite size (ca. 17.4 nm). In addition, the antibacterial effects of the Li-doped MgO nanoparticles against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) are evaluated by using a bacterial killing/colony forming unit (CFU) assay. The results demonstrate that the antimicrobial activity of the Li-doped MgO varies according to the synthesis fuel, with the citric acid fuel inducing the best antimicrobial activity. The antibacterial mechanisms of the Li-doped MgO nanoparticles are also characterized. [ABSTRACT FROM AUTHOR]

Diverse engineering nanoparticles (NPs) have found their way into the environment due to their extensive applications. The widespread occurrence of NPs may affect the fate of the coexisting pollutants and other types of NPs in natural waters. This study investigated the heteroadsorption of pollutants to multiple NPs in simulated water environment. Particular attention was paid to the impact of two common metal oxide (MO) NPs, Fe 2 O 3 and ZnO, on the adsorption of 17β-estradiol (E2) to carbon nanotubes (CNTs). The results showed that the presence of Fe 2 O 3 and ZnO significantly increased the time to reach adsorption equilibrium for the adsorption of E2 to CNTs. The adsorption amount of E2 increased with increasing Fe 2 O 3 /CNTs ratio due to the adsorption of E2 to Fe 2 O 3 . In contrast, E2 adsorption was slightly inhibited by the presence of ZnO, resulting from the blockage of the adsorption sites on CNT surface by ZnO. DLVO theory calculation exhibited that Fe 2 O 3 were likely to first homoaggregate and then heteroaggregate with CNTs, whereas the electrostatic attraction between oppositely charged ZnO and CNTs favored their heteroaggregation in the heterogeneous systems of CNTs and ZnO. This was confirmed by the transmission electron microscopy images and the thermo-gravimetric analysis. The findings highlighted the significant effects of MO on the adsorption of organic compounds to CNTs, and also provided better understanding of the fate and transport of CNTs and organic contaminants in natural aquatic environments, where they inevitably coexist with MO. [ABSTRACT FROM AUTHOR]

Abstract: The aggregation/sedimentation potentials of TiO2 nanoparticles were studied in mono- and binary systems of Suwannee River fulvic acids (SRFA) and Fe(III) at different pH values. SRFA adsorption significantly enhanced the stability of TiO2 nanoparticles at pH 4, 6 and 8, mainly due to the dramatic increase in negative surface charges. The presence of Fe(III) stabilized aggregation/sedimentation of TiO2 nanoparticles at pH 4 due to the increasing positive charges after Fe(III) sorption, but destabilized aggregation/sedimentation at pH 6 and 8 attributed to the bridging effect of Fe(III)-hydroxy. The formation of COO–Fe(III) complex was found in binary system of SRFA and Fe(III). Thus, the positive charges that Fe(III) imparted to nanoparticles were neutralized by SRFA. Compared with those in mono-system of Fe(III), SRFA enhanced aggregation/sedimentation at pH 4, while stabilized TiO2 nanoparticles at higher pH in binary system of SRFA and Fe(III). The sedimentation rates of TiO2 nanoparticles showed relatively lower coefficient with zeta potentials (−0.883, P <0.01) than with hydrodynamic particle sizes (0.964, P <0.01), due to the steric hindrance of SRFA and the bridging effect of Fe(III)-hydroxy, which was confirmed by DLVO calculation. These results have important implications for prediction of the stability and fate of nanoparticles in natural water. [Copyright &y& Elsevier]

Formic acid (HCOOH, FA), a common liquid hydrogen storage material, has attracted tremendous research interest. However, the development of efficient, low-cost and high-stable heterogeneous catalyst for selective dehydrogenation of FA remains a major challenge. In this paper, a simple co-reduction method is proposed to synthesize nitrogen-phosphorus co-functionalized rGO (NPG) supported ultrafine NiCoPd-CeO x nanoparticles (NPs) with a mean size of 1.2 nm. Remarkably, the as-prepared Ni 0.2 Co 0.2 Pd 0.6 -CeO x /NPG shows outstanding catalytic activity for FA dehydrogenation, affording a high TOF value of 6506.8 mol H 2 mol Pd−1 h−1 at 303 K and a low activation energy of 17.7 kJ mol−1, which is better than most of the reported heterogeneous catalysts, and can be ascribed to the combined effect of well-dispersed ultrafine NiCoPd-CeO x NPs, modified Pd electronic structure, and abundant active sites. The reaction mechanism of dehydrogenation of FA is also discussed. Furthermore, the optimized Ni 0.2 Co 0.2 Pd 0.6 -CeO x /NPG shows excellent stability over 10th run with 100% conversion and 100% H 2 selectivity, which may provide more possibilities for practical application of FA system on fuel cells. [Display omitted] • N–P co-functionalized rGO supported ultrafine NiCoPd-CeO x NPs are successfully synthesized via a simple co-reduction method. • NPG has a positive effect on improving the distribution and controlling particle size. • The Ni 0.2 Co 0.2 Pd 0.6 -CeO x /NPG exhibits high activity towards FA dehydrogenation, giving a TOF of 6506.8 h−1 at 303 K. • The Ni 0.2 Co 0.2 Pd 0.6 -CeO x /NPG shows excellent stability and activity even after 10th run. [ABSTRACT FROM AUTHOR]

Abstract: A novel natural rubber/silica (NR/SiO2) nanocomposite is developed by combining self-assembly and latex-compounding techniques. The results show that the SiO2 nanoparticles are homogenously distributed throughout NR matrix as nano-clusters with an average size ranged from 60 to 150nm when the SiO2 loading is less than 6.5wt%. At low SiO2 contents (⩽4.0wt%), the NR latex (NRL) and SiO2 particles are assembled as a core-shell structure by employing poly (diallyldimethylammonium chloride) (PDDA) as an inter-medium, and only primary aggregations of SiO2 are observed. When more SiO2 is loaded, secondary aggregations of SiO2 nanoparticles are gradually generated, and the size of SiO2 cluster dramatically increases. The thermal/thermooxidative resistance and mechanical properties of NR/SiO2 nanocomposites are compared to the NR host. The nanocomposites, particularly when the SiO2 nanoparticles are uniformly dispersed, possess significantly enhanced thermal resistance and mechanical properties, which are strongly depended on the morphology of nanocomposites. The NR/SiO2 has great potential to manufacture medical protective products with high performances. [Copyright &y& Elsevier]

Abstract: A novel polyvinylalcohol/silica (PVA/SiO2) nano-composite is prepared with the self-assembly monolayer (SAM) technique. The SiO2 nano-particles are homogenously distributed throughout the PVA matrixes as nano-clusters with an average diameter ranged from 15 to 240nm depending on the SiO2 contents. Using differential scanning calorimetry (DSC), the non-isothermal crystallisation behaviour and kinetics of the PVA/SiO2 nano-composites are investigated and compared to those of the pure PVA. There are strong dependences of the degree of crystallinity (Xc), peak crystallisation temperature (Tp), half time of crystallisation (t1/2), and Ozawa exponent (m) on the SiO2 content and cooling rate. The crystallisation activation energy (E) calculated with the Kissinger model is markedly lower when a small amount of SiO2 is added, then gradually increases and finally becomes higher than that of the pure PVA when there is more than 10% SiO2 in the composite. [Copyright &y& Elsevier]

Two Schiff base ligands 2-((ethylamino)methyl)-6-methoxyphenol (HL 1) and (E)-2-(((2-(dimethylamino)ethyl)imino)methyl)-6-methoxyphenol (HL 2) with bi-nucleating or tri-nucleating mode have been successfully prepared via an one step organic condensation reaction, which were further applied in the synthesis of three new Cu(II) and Ni(II)-based coordination complexes [Cu(L 1) 2 ](EtOH) (1), [Ni(L 1) 2 ](EtOH) (2) and [Cu(L 2)(HL 2)(SCN)](MeOH) 2 (3). Furthermore, a hand grinding technique has been used to decrease the particle diameter of complexes 1 – 3 , thus forming nano-complexes. In biological activity research, we revealed the important function of nanoparticle 1 in the treatment of breast cancer. Mitochondria is critical in generating intracellular energy, and play a vital role in regulating cells life and death. Therefore, the apoptosis of MCF7 breast cancer cells after treated with nanoparticles was detected by Annexin V-FITC/PI method. The results showed that nanoparticles 1 could significantly raise apoptotic cells number, but not nanoparticles 2–3. Moreover, we assessed the mitochondrial membrane potential and reactive oxygen species (ROS) in MCF7 cancer cells, finally we draw this conclusion, nanoparticle 1 could damage the mitochondrial membrane, leading increased ROS level, and cause the apoptotic cell death. • Three new Cu(II) and Ni(II)-based coordination complexes were synthesized. • A hand grinding technique has been used to get nano-complexes. • We revealed the important function of nanoparticle 1 in the treatment of breast cancer. [ABSTRACT FROM AUTHOR]

This study investigated the water-organic co-solvent for the fractionation of lignin in camellia oleifera shell and further fabrication of lignin nanoparticles (LNPs). The highest dissolution (88.6 wt%) of lignin was obtained in H 2 O/GVL (3/7, v/v) co-solvent, which was mainly ascribed to the adjacent Hildebrand solubility parameter (δ) between lignin and co-solvent. The LNPs prepared by solvent-shifting method and precipitation exhibited round or oval shape with even distribution. Among which, LNPs obtained from the lignin fraction dissolved in H 2 O-ethanol co-solvent (denoted as LNP-ETH) showed the smallest average particle size of 136 nm and the highest negative zeta potential of − 39.6 mV, which implied the relatively stable lignin nanoparticles prepared from H 2 O-ETH co-solvent. The structural analysis of lignin nanoparticles revealed that LNPs maintained the lignin aromatic skeleton, C-O-C/C-C linkages and basic structural units (G, S and H). So far, this research offered great potential for the preparation of lignin-based materials from abundant forestry waste camellia shell. [Display omitted] • Well-distributed and small-sized LNPs were obtained from waste camellia shell. • The highest dissolution (88.6 wt%) of lignin was obtained in H 2 O/GVL co-solvent. • LNP-ETH showed the smallest average particle size of 136 nm. • The highest negative zeta potential of − 39.6 mV was observed in LNP-ETH. • LNPs maintained the lignin aromatic skeleton and basic structural units. [ABSTRACT FROM AUTHOR]

In recent years, the solution enhanced dispersion in supercritical fluids (SEDS) technique is widely applied to produce fine and small particles of drugs and other active ingredients. However, this technique still cannot be used to generate particles in the submicrometer range for specific compounds, such as carotenoids. In this study, a modified SEDS technique is explored and applied in the preparation of β-carotene nanoparticles with relatively narrow size distribution. This novel technique, termed SEDS-EM, combines a traditional SEDS technique with ultrasonication from the supercritical antisolvent with enhanced mass transfer precipitation technique (SAS-EM). For this new technique, the β-carotene solution is premixed with the antisolvent (supercritical CO2) in a coaxial nozzle; then the mixed solution is sprayed from the coaxial nozzle onto a surface vibrating at an ultrasonic frequency. The solution jet is dispersed by the coaxial nozzle and further atomized into very small droplets by the ultrasonic vibrating surface. This combination of a coaxial nozzle and the ultrasound field enhances the mass transfer between the solution and the antisolvent. The resultant β-carotene particles decreased in size from the micrometer range (2–5 μm) by SEDS to the nanometer range (20–205 nm) by SEDS-EM. This smaller particle size can be controlled by the power supplied from the attached ultrasound transducer utilized in SEDS-EM. The size and morphology of the particles are observed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The effects of the process parameters on the β-carotene yield are discussed. The crystallography transformation of the processed and unprocessed β-carotene is characterized by XRD and FTIR. The particle precipitation in sub and near critical regions of the DCM-CO2binary system is also discussed. [ABSTRACT FROM AUTHOR]