Effect of a Hybrid Micro/Nano-integrated Titanium Surface on Behavior of Rat Osteoblasts

The objective of this study was to investigate the effect of a new combined micro/nanoscale implant surface feature on osteoblasts＇ behaviors including cell morphology, adhesion, proliferation, differentiation, and mineralization in vitro. A new micro/nano-hybrid topography surface was fabricated on commercial pure titanium（Cp Ti） by a two-step sandblasted acid-etching and subsequent alkali-and heattreatment（SA-AH）. The conventional sandblasted/acid-etching（SA） treatment and alkali and heat（AH） treatment were also carried out on the Cp Ti as controls. Surface microstructures of the Ti disc samples were assessed by scanning electron microscopy（SEM）. The neonatal rat calvaria-derived osteoblasts were seeded on these discs and the initial cell morphology was evaluated by SEM and immunofluorescence. Initial adhesion of the cells was then assayed by DAPI staining at 1, 2, and 4 h after seeding. The Cell Counting Kit-8（CCact K8） assay, gene expression of osteoblastic markers（ALP, Col 1, OCN, BSP, OSX, Cbfα1） and Alizarin Red S staining assays were monitored respectively for cell proliferations, differentiation and mineralization. The results show significant differences in osteoblast＇s behaviors on the four kinds of Ti surfaces. Compared with Cp Ti surface, the SA and AH treatment can significantly promote cell adhesion, differentiation and mineralization of osteoblasts. In particular, the combined SA and AH treatments exhibit synergistic effects in comparison with the treatment of SA and AH individually, and are more favorable for stimulating a series of osteogenous responses from cell adhesion to mineralization of osteoblasts. In summary, this study provides some new evidence that the integrated micro/nanostructure on the Cp Ti surface may promote bone osseointegration between the Ti implantbone interfaces in vitro.

Nonlinear frequency conversion in optical nanoantennas and metasurfaces:materials evolution and fabrication

Nonlinear frequency conversion is one of the most fundamental processes in nonlinear optics.It has a wide range of applications in our daily lives,including novel light sources,sensing,and information processing.It is usually assumed that nonlinear frequency conversion requires large crystals that gradually accumulate a strong effect.However,the large size of nonlinear crystals is not compatible with the miniaturisation of modern photonic and optoelectronic systems.Therefore,shrinking the nonlinear structures down to the nanoscale,while keeping favourable conversion efficiencies,is of great importance for future photonics applications.In the last decade,researchers have studied the strategies for enhancing the nonlinear efficiencies at the nanoscale,e.g.by employing different nonlinear materials,resonant couplings and hybridization techniques.In this paper,we provide a compact review of the nanomaterials-based efforts,ranging from metal to dielectric and semiconductor nanostructures,including their relevant nanofabrication techniques.

Temperature-Responsive Tensile Actuator Based on Multi-walled Carbon Nanotube Yarn

Many temperature indicators or sensors show color changes for materials used in food and medical fields.However, they are not helpful for a color-blind person or children who lack judgment. In this paper, we introduce simply fabricated and more useful low-temperature indicator(~30 °C) for devices that actuates using paraffin-infiltrated multiwalled carbon nanotube(MWCNT) coiled yarn. The density difference of MWCNT yarn provides large strain(~330 %)when heat causes the melted polymer to move. Furthermore, the MWCNT yarn decreases the melting point of paraffin.These properties allow control of the actuating temperature. In addition, mechanical strength was enhanced by MWCNT than previously reported temperature-responsive actuators based on shape memory polymers. This simply fabricated temperature indicator can be applied in latching devices for medical and biological fields.

Waste to wealth: Oxygen-nitrogen-sulfur codoped lignin-derived carbon microspheres from hazardous black liquors for high-performance DSSCs

Carbon materials are effective substitutes for Pt counter electrodes(CEs) in dye-sensitized solar cells(DSSCs). However, many of these materials, such as carbon nanotubes and graphene, are expensive and require complex preparation process. Herein, waste lignin, recycled from hazardous black liquors,is used to create oxygen-nitrogen-sulfur codoped carbon microspheres for use in DSSC CEs through the facile process of low-temperature preoxidation and high-temperature self-activation. The large number of ester bonds formed by preoxidation increase the degree of cross-linking of the lignin chains, leading to the formation of highly disordered carbon with ample defect sites during pyrolysis. The presence of organic O/N/S components in the waste lignin results in high O/N/S doping of the pyrolysed carbon,which increases the electrolyte ion adsorption and accelerates the electron transfer at the CE/electrolyte interface, as confirmed by density functional theory(DFT) calculations. The presence of inorganic impurities enables the construction of a hierarchical micropore-rich carbon structure through the etching effect during self-activation, which can provide abundant catalytically active sites for the reversible adsorption/desorption of electrolyte ions. Under these synergistic effects, the DSSCs that use this novel carbon CE achieve a quite high power-conversion efficiency of 9.22%. To the best of our knowledge, the value is a new record reported so far for biomass-carbon-based DSSCs.

Putting PLX5622 into perspective:microglia in central nervous system viral infection

Elucidating the exact contribution of microglia to central nervous system(CNS)pathology has historically been extremely challenging.These resident parenchymal myeloid cells are considered to have critical roles as frontline responders during pathogen invasion and CNS perturbation.Thus,understanding the precise temporal kinetics of microglial function is central to the evolution of novel therapeutics for disease intervention and/or resolution(Spiteri et al.,2022a).The development of PLX5622,a colony-stimulating factor 1 receptor(CSF-1R)inhibitor typically formulated into a rodent chow for simple oral administration has facilitated exploration of microglial functions in disease(Spangenberg et al.,2019).

Corrosion characteristics of single-phase Mg-3Zn alloy thin film for biodegradable electronics

Biodegradable metals as electrodes, interconnectors, and device conductors are essential components in the emergence of transient electronics, either for passive implants or active electronic devices, especially in the fields of biomedical electronics. Magnesium and its alloys are strong candidates for biodegradable and implantable conducting materials because of their high conductivity and biocompatibility, in addition to their well-understood dissolution behavior. One critical drawback of Mg and its alloys is their considerably high dissolution rates originating from their low anodic potential, which disturbs the compatibility to biomedical applications. Herein, we introduce a single-phase thin film of a Mg-Zn binary alloy formed by sputtering, which enhances the corrosion resistance of the device electrode, and verify its applicability in biodegradable electronics. The formation of a homogeneous solid solution of single-phase Mg-3Zn was confirmed through X-ray diffraction and transmission electron microscopy. In addition, the dissolution behavior and chemistry was also investigated in various biological fluids by considering the effect of different ion species. Micro-tensile tests showed that the Mg-3Zn alloy electrode exhibited an enhanced yield strain and elongation in relation to a pure Mg electrode. Cell viability test revealed the high biocompatibility rate of the Mg-3Zn binary alloy thin film. Finally, the fabrication of a wireless heater demonstrated the integrability of biodegradable electrodes and highlighted the ability to prolong the lifecycle of thermotherapy-relevant electronics by enhancing the dissolution resistance of the Mg alloy.

Oxide-based cathode materials for rechargeable zinc ion batteries:Progresses and challenges

With the increasing demands for electrical energy storage technologies,rechargeable zinc ion batteries(ZIBs)have been rapidly developed in recent years owing to their high safety,low cost and high energy storage capability.The cathode is an essential part of ZIBs,which hosts zinc ions and determines the capacity,rate and cycling performance of the battery.The mainstream cathodes for ZIBs are oxidebased materials with tunnel,layer or 3 D crystal structures.In this review,we mainly focus on the latest advanced oxide-based cathode materials in ZIBs,including manganese oxides,vanadium oxides,spinel compounds,and other metal oxide based cathodes.In addition,the mechanisms of zinc storage and recent development in cathode design have been discussed in detail.Finally,current challenges and perspectives for the future research directions of oxide-based cathodes in ZIBs are presented.

Decomposition behaviors of methane hydrate in porous media below the ice melting point by depressurization

The decomposition behaviors of methane hydrate below the ice melting point in porous media with different particle size and different pore size were studied.The silica gels with the particle size of 105–150μm,150–200μm and 300–450μm,and the mean pore diameters of 12.95 nm,17.96 nm and 33.20 nm were used in the experiments.Methane recovery and temperature change curves were determined for each experiment.The hydrate decomposition process in the experiments can be divided into the depressurization period and the isobaric period.The temperature in the system decreases quickly in the depressurization process with the hydrate decomposition and reaches the lowest point in the isobaric period.The hydrate decomposition in porous media below ice-melting point is very fast and no self-perseveration effect is observed.The hydrate decomposition is influenced both by the driving force and the initial hydrate saturation.In the experiments with the high hydrate saturation,the hydrate decomposition will stop when the pressure reaches the equilibrium dissociation pressure.The stable pressure in the experiment with high hydrate saturation exceeds the equilibrium dissociation pressure of bulk hydrate and increases with the decrease of the pore size.

Influence of hierarchical ZSM-5 catalysts with various acidity on the dehydration of glycerol to acrolein

The main challenge in the dehydration of glycerol to acrolein lies in overcoming catalystdeactivation and improving the selectivity to acrolein. The relationship between theacidity in the mesoporous channels and catalytic performance of glycerol dehydration israrely reported. In this work, to investigate the influence of acidity in the mesoporouschannels of hierarchical ZSM-5 catalysts on the dehydration of glycerol to acrolein, a seriesof hierarchical ZSM-5 zeolites with comparable mesoporous volume and mesoporous sizebut different acid properties in mesopores have been successfully prepared via alkalinetreatment. The sample with the abundant mesoporosity and highest acidity display thebest performance.

五配位铝强化硅铝固体酸的固体核磁共振研究

Brønsted酸(B酸)是无定型硅铝(ASAs)表面最重要的催化活性位点.通常认为B酸位的形成只依赖于不饱和四配位铝(AlIV),且仅具有弱B酸性.通过合成五配位铝(AlV)富集的ASAs能够大幅提升高铝硅比(Al/Si)时的B酸含量及强度,克服传统AlIV富集的ASAs的酸性强化瓶颈.本文介绍了AlV在ASAs酸性强化及合成单原子催化剂中的重要作用.通过采用多种二维固体核磁共振(SSNMR)及原位质子NMR技术,证明了AlV能够大量富集在ASAs表面,着重介绍了两种基于AlV的新B酸位的形成机制,并阐明了AlV诱导单原子催化剂在ASAs表面形成的机理.

Dynamic covalent nano-networks comprising antibiotics and polyphenols orchestrate bacterial drug resistance reversal and inflammation alleviation

New antimicrobial strategies are urgently needed to meet the challenges posed by the emergence of drug-resistant bacteria and bacterial biofilms.This work reports the facile synthesis of antimicrobial dynamic covalent nano-networks(aDCNs)composing antibiotics bearing multiple primary amines,polyphenols,and a cross-linker acylphenylboronic acid.Mechanistically,the iminoboronate bond drives the formation of aDCNs,facilitates their stability,and renders them highly responsive to stimuli,such as low pH and high H2O2 levels.Besides,the representative A1B1C1 networks,composed of polymyxin B1(A1),2-formylphenylboronic acid(B1),and quercetin(C1),inhibit biofilm formation of drug-resistant Escherichia coli,eliminate the mature biofilms,alleviate macrophage inflammation,and minimize the side effects of free polymyxins.Excellent bacterial eradication and inflammation amelioration efficiency of A1B1C1 networks are also observed in a peritoneal infection model.The facile synthesis,excellent antimicrobial performance,and biocompatibility of these aDCNs potentiate them as a much-needed alternative in current antimicrobial pipelines.

通过具有高表面能和延长共轭链段的耐溶剂空穴传输材料实现高效喷墨打印QLED

量子点发光二极管(QLED)溶液法制备的特点和喷墨打印高度契合,在印刷显示器领域展现出巨大的应用潜力.制作QLED器件时,下层薄膜的表面能对上层薄膜的铺展起着至关重要的作用,高表面能可以促进不同功能膜层之间的紧密接触并减少漏电流.然而,已报道的交联空穴传输材料(HTM)低的表面能不利于喷墨打印.在此,我们通过分子设计开发了一种可交联HTM及其聚合物,新的聚合物命名为[9-(4-(乙氧基甲基)苯基)-3-(7-(9-(4-(己炔基)乙氧基甲基)苯基)-9H-咔唑-3-基)-9H-芴]-9H-咔唑(PDA-FLCZ),由3,3′-(9,9-二甲基-9H-芴-2,7-二基)双[9-(4-(丙-2-炔-1-氧基)甲基)苯基]-9H-咔唑(DA-FLCZ)聚合得到.这种新型HTM采用原位光热交联和预聚后热交联两种交联策略,都可以在较低的交联温度下形成稳定的网络结构,具有优异的耐溶剂性和较高的表面能.通过优化交联工艺,交联PDA-FLCZ薄膜实现了更高的空穴迁移率和更低的陷阱密度,其对应的旋涂QLED器件的最大外量子效率(EQE)达到17.59%,比基于DA-FLCZ的器件(14.25%)高出23%.此外,基于交联PDA-FLCZ的喷墨打印QLED显示出15.28%的最大EQE,接近其旋涂器件值的90%.

Biomimetic albumin-modified gold nanorods for photothermo-chemotherapy and macrophage polarization modulation

Nanotechnology-based photothermal therapy has attracted great attention in the past decade. Nevertheless, photothermal therapy has some inherent drawbacks, such as the uneven heat production and limited laser penetration, often leading to insufficient treatment outcomes. Here, we developed a combination strategy to improve cancer therapy. The biomimetic albumin-modified gold nanorods(AuNRs) were prepared with incorporation of paclitaxel(PTX). This therapeutic system was characterized by several features. First, the albumin modification enhanced the biocompatibility and colloidal stability. Second, the surface-coated albumin promoted cellular uptake via the albumin-binding protein pathway. Third, PTX was incorporated via hydrophobic interaction between PTX and the albumin lipophilic domain. Fourth, the system can be used for combined photothermo-chemotherapy for yielding synergistic effects. The antitumor activity of the system was evaluated both in vitro and in vivo using the HCT116 colon cancer cell and tumor model. The combination therapy was found with an enhanced treatment efficiency and no obvious side effect. Most importantly, the thermal effect was also discovered with the ability to modulate the tumor microenvironments and suppress the macrophages polarization towards the M2 pro-tumor phenotype. It could be a mechanism for photothermal immunotherapy. The combination strategy and the system provide a potential method for cancer therapy.

Use of compositional and combinatorial nanomaterial libraries for biological studies

The rapid development and production of nanomaterials has created some concerns about their potential hazard on the environment,human health and safety.However,since the list of materials that may generate such concerns is very long,it is impossible to test them all.It is therefore usually recommended to use some small compositional nanomaterial libraries to perform initial toxicity screening,based on which combinatorial libraries are then introduced for more in-depth studies.All nanomaterials in the compositional and combinatorial libraries must be rigorously characterized before any biological studies.In this review,several major categories of physicochemical properties that must be characterized are discussed,along with different analytical techniques that are commonly used.Some case studies from the University of California Center for Environmental Implications of Nanotechnology are also chosen to demonstrate the effective use of compositional and combinatorial nanomaterials libraries to identify the role of some key physicochemical properties and to establish true quantitative structure–activity relationships.Examples on how to use the knowledge generated from those studies to design safer nanomaterials for improved biological applications are also presented.

Evolution of stellated gold nanoparticles:New conceptual insights into controlling the surface processes

Understanding the surface processes(deposition and surface diffusion)that occur at or close to the surface of growing nanoparticles is important for fabricating reproducibly stellated or branched gold nanoparticles with precise control over arm length and spatial orientation of arms around the core.By employing a simple seed-mediated strategy,we investigate the key synthetic variables for precise tuning of in situ surface processes(competition between the deposition and surface diffusion).These variables include the reduction rate of a reaction,the packing density of molecules/ions on the high surface energy facets,and temperature.As a result,the thermodynamically stabilized nanoparticles(cuboctahedron and truncated cube)and kinetic products(cube,concave cube,octapod,stellated octahedron,and rhombic dodecahedron)in different sizes with high quantitative shape yield(>80%)can be obtained depending on the reduction rate of reaction and the packing density of molecules/ions.With computer simulation,we studied the stability of stellated(branched structure)and non-stellated(non-branched structure)gold nanoparticles at high temperature.We construct a morphology phase diagram by varying different synthetic parameters,illustrating the formation of both stellated and non-stellated gold nanoparticles in a range of reaction conditions.The stellated gold nanoparticles display shape-dependent optical properties and can be self-assembled into highly ordered superstructures to achieve an enhanced plasmonic response.Our strategy can be applied to other metal systems,allowing for the rational design of advanced new stellated metal nanoparticles with fascinating symmetry dependent plasmonic,catalytic,and electronic properties for technological applications.

The inaugural Nano Research Young Innovators （NR45） Award in nanobiotechnology

It is our great pleasure to announce awardees of the inaugural 2018 Nano Research Young Innovators （NR45） in nanobiotechnology. Congratulations to all of the 45 outstanding young investigators under 45! They were selected through a competitive process by an award committee from our editorial board. Nano Research is launching the NR45 Award program to young researchers in various fields of nanoscience and nanotechnology, in recognition to their distinguished accomplishments and/or potential to make substantial contributions to their fields. The aim of Nano Research NR45 is to recognize the outstanding contributions of young scientists and together with the Nano Research Symposium integrated in the annual US-SINO Nano Forum provide a platform for communication, discussions and collaborations between scientists inter- nationally. For this inaugural year.

Upconversion nanoparticle mediated optogenetics for targeted deep brain stimulation

Brain is often called the last frontier in science[1].It is such an important organ that controls our mind and behavior,yet we know so little about it.The gel-like tissue is probably the most complicated object in the universe because it contains about 100 billion nerve cells,equal to the number of stars in our galaxy,the Milky Way.Each neuron is connected to thousands of other nerve cells by up to 40,000 individual connections called synapses。

Heteronanostructural metal oxide-based gas microsensors

The development of high-performance,portable and miniaturized gas sensors has aroused increasing interest in the fields of environmental monitoring,security,medical diagnosis,and agriculture.Among different detection tools,metal oxide semiconductor(MOS)-based chemiresistive gas sensors are the most popular choice in commercial applications and have the advantages of high stability,low cost,and high sensitivity.One of the most important ways to further enhance the sensor performance is to construct MOS-based nanoscale heterojunctions(heteronanostructural MOSs)from MOS nanomaterials.However,the sensing mechanism of heteronanostructural MOS-based sensors is different from that of single MOS-based gas sensors in that it is fairly complex.The performance of the sensors is influenced by various parameters,including the physical and chemical properties of the sensing materials(e.g.,grain size,density of defects,and oxygen vacancies of materials),working temperatures,and device structures.This review introduces several concepts in the design of high-performance gas sensors by analyzing the sensing mechanism of heteronanostructural MOS-based sensors.In addition,the influence of the geometric device structure determined by the interconnection between the sensing materials and the working electrodes is discussed.To systematically investigate the sensing behavior of the sensor,the general sensing mechanism of three typical types of geometric device structures based on different heteronanostructural materials are introduced and discussed in this review.This review will provide guidelines for readers studying the sensing mechanism of gas sensors and designing high-performance gas sensors in the future.

Evidence for interlayer coupling and moiréexcitons in twisted WS_(2)/WS_(2)homostructure superlattices

The formation of moirésuperlattices in twisted van der Waals(vdW)homostructures provides a versatile platform for designing the electronic band structure of two-dimensional(2D)materials.In graphene and transition metal dichalcogenides(TMDs)moirésystems,twist angle has been shown to be a key parameter for regulating the moirésuperlattice.However,the effect of the modulation of the twist angle on moirépotential and interlayer coupling has not been the subject of experimental investigation.Here,we report the observation of the modulation of moirépotential and intralayer excitons in the WS_(2)/WS_(2)homostructure.By accurately adjusting the torsion angle of the homobilayers,the depth of the moirépotential can be modulated.The confinement effect of the moirépotential on the intralayer excitons was further demonstrated by the changing of temperature and valley polarization.Furthermore,we show that a detection of atomic reconstructions by the low-frequency Raman mapping to map out inhomogeneities in moirélattices on a large scale,which endows the uniformity of interlayer coupling.Our results provide insights for an in-depth understanding of the behaviors of moiréexcitons in the twisted van der Waals homostructure,and promote the study of electrical engineering and topological photonics.

Effect of layered-coupling in twisted WSe_(2) moiré superlattices

Recently,the discovery of a variety of moiré-related properties in the twisted vertical stacking of two different monolayers has attracted considerable attention.The introduction of small twist angles in transition metal dichalcogenide(TMD)heterostructures leads to the emergence of moirépotentials,which provide a fascinating platform for the study of strong interactions of electrons.While there has been extensive research on moiréexcitons in twisted bilayer superlattices,the capture and study of moiréexcitons in homostructure superlattices with layer-coupling effects remain elusive.Here,we present the observation of moiréexcitons in the twisted 1L-WSe_(2)/1L-WSe_(2)and 1L-WSe_(2)/2L-WSe_(2)homostructures with various layer-coupling interactions.The results reveal that the moirépotential increases(~260%)as the number of underlying layers decreases,indicating the effect of layer coupling on the modulation of the moirépotential.The effects of the temperature and laser power dependence as well as valley polarization on moiréexcitons were further demonstrated,and the crucial spectral features observed were explained.Our findings pave the way for exploring quantum phenomena and related applications of quantum information.