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Semiconductor electrocatalysis with weak conductivity can accumulate extremely high carriers at semiconductor-electrolyte interface by self-gating effect, which strongly promotes electrocatalytic efficiency. The correlation between semiconductor carrier mobility and electrocatalysis performance is still unclear. Herein atomic-thin transition metal dichalcogenides based composites have been developed for hydrogen evolution reaction (HER) performed with on-chip microdevices. Electrical and electrochemical measurement of individual flack verified the key role of high carrier mobility for enhanced HER activity. Carrier mobility regulation further demonstrated its high dependence with HER performance under self-gating. Our study provides new insight into the carrier mobility of the semiconductor in the electrocatalysis, paving the way for designing high-performance semiconductor catalysts.

The oxygen vacancy-rich perovskite La0.9FeO3−δ was employed as an electrocatalyst to reduce nitrate to ammonia and obtained the highest NH3 yield of 1024.8 μg h−1 cm−2 at −1.0 V (vs. RHE) and a faradaic efficiency of 78.1% at −0.8 V (vs. RHE).

Machine learning approach was employed to guide the fabrication of blue carbon dots(CDs) with excellent result. The quantum yield of the CDs can increase up to 200% and can be used as fluorescent probes for bleaching teeth H2O2 detection.

Supplementary material and methods

Supplementary Table S1. Antibodies Used in the Study Supplementary Table S2. Characterization of LPD NPs Supplementary Table S3. Primers Used in the Study Supplementary Table S4. Blood Chemistry after Treatments Supplementary Figure S1. Morphology and in vivo biodistribution of LPD NPs. Supplementary Figure S2. Histology (H&E, left; IF, right; adjacent sections) of mice bearing UMUC3/3T3 tumors. Supplementary Figure S3. Calculation of DiI positive cells in each cell population within UMUC/3T3 xenograft tumors by flow cytometry (n=4). Supplementary Figure S4. In vitro transfection efficiency of sTRAIL or TRAIL loaded LPD on UMUC3 bladder cancer cell line. Supplementary Figure S5. Neighboring tumor-suppressive effect of the secreted TRAIL protein. Supplementary Figure S6. qPCR quantitation of relative mRNA levels of sTRAIL in the UMUC3/3T3 tumors after different treatments. Supplementary Figure S7. ELISA quantification of the expression and secretion of sTRAIL protein in the UMUC3/3T3 tumors after different treatments. Supplementary Figure S8. Collagen remodeling during the dose escalation of sTRAIL LPD. Supplementary Figure S9. Remodeling of tumor microenvironment after sTRAIL LPD treatment. Supplementary Figure S10. Histology (both fibroblast staining and collagen staining) of orthotopic BXPC3-Luc2 mouse xenograft. Supplementary Figure S11. sTRAIL LPD inhibited the metastasis of BXPC3-Luc2 tumors Supplementary Figure S12. Expression of GFP within different cell populations of BXPC3-Luc2 tumors after 3 doses of sTRAIL or TRAIL NPs (co-expressing GFP). Supplementary Figure S13. Collagen staining of tumors from mice treated with PBS and sTRAIL LPD NP, respectively. Supplementary Figure S14. In vivo cytotoxicity evaluation and organ distribution of sTRAIL or TRAIL LPD. Supplementary Figure S15. Apoptosis of neighboring tumor cells reduces the activation of fibroblasts.

The off-target distribution of anticancer nanoparticles to fibroblasts creates a barrier to the effective treatment of desmoplastic tumors. However, we hypothesized that this nanoparticle detriment might be exploited to target the expression of secreted cytotoxic proteins from tumor-associated fibroblasts (TAF) as an anticancer strategy. In addressing this hypothesis, plasmids encoding the secretable TNF-related factor sTRAIL were loaded into lipid-coated protamine DNA complexes and administered by infusion in a murine xenograft model of human desmoplastic bladder carcinoma. Three doses were sufficient to generate approximately 70% of TAFs as sTRAIL-producing cells. sTRAIL triggered apoptosis in tumor cell nests adjacent to TAFs. Furthermore, it reverted residual fibroblasts to a quiescent state due to insufficient activation, further compromising tumor growth and remodeling the microenvironment to favor second-wave nanotherapy. We confirmed the efficacy of this strategy in an orthotopic xenograft model of human pancreatic cancer, where the desmoplastic stroma is well known to be a major barrier to the delivery of therapeutic nanoparticles. Collectively, our results offer a proof of concept for the use of nanoparticles to modify TAFs as an effective strategy to treat desmoplastic cancers. Cancer Res; 77(3); 719–31. ©2016 AACR.

An integrated physiologically based modeling framework is presented for predicting pharmacokinetics and bioavailability of subcutaneously administered monoclonal antibodies in cynomolgus monkeys, based on in silico structure-derived metrics characterizing antibody size, overall charge, local charge, and hydrophobicity. The model accounts for antibody-specific differences in pinocytosis, transcapillary transport, local lymphatic uptake, and pre-systemic degradation at the subcutaneous injection site and reliably predicts the pharmacokinetics of five different wild-type mAbs and their Fc variants following intravenous and subcutaneous administration. Significant associations were found between subcutaneous injection site degradation rate and the antibody's local positive charge of its complementarity-determining region (R = 0.56, p = 0.0012), antibody pinocytosis rate and its overall positive charge (R = 0.59, p = 0.00063), and antibody paracellular transport and its overall charge together with hydrophobicity (R = 0.63, p = 0.00096). Based on these results, population simulations were performed to predict the relationship between bioavailability and antibody local positive charge. In addition, model simulations were conducted to calculate the relative contribution of absorption pathways (lymphatic and blood), pre-systemic degradation pathways (interstitial and lysosomal), and the influence of injection site lymph flow on antibody bioavailability and pharmacokinetics. The proposed physiologically based modeling framework integrates fundamental mechanisms governing antibody subcutaneous absorption and disposition, with structured-based physiochemical properties, to predict antibody bioavailability and pharmacokinetics in vivo.

Compared to traditional rigid-bodied robots, soft robots are constructed using physically flexible/elastic bodies and electronics to mimic nature and enable novel applications in industry, healthcare, aviation, military,etc.

Strong, reversible, and self-cleaning adhesion in the toe pads of geckos allow the lizards to climb on a variety of vertical and inverted surfaces, regardless of the surface conditions, whether hydrophobic or hydrophilic, smooth or tough, wet or dry, clean or dirty. Development of synthetic gecko-inspired surfaces has drawn a great attention over the past two decades. Despite many external-stimuli responsive mechanisms (i.e., thermal, electrical, magnetic) have been successfully demonstrated, smart adhesives controlled by light signals still substantially lag behind. Here, in this report, we integrate tetramethylpiperidinyloxyl (TEMPO)-doped polydopamine (PDA), namely, TDPDA, with PDMS micropillars using a template-assisted casting method, to achieve both improved adhesion and self-cleaning performances. To the best of our knowledge, this is the first report on PDA being used as a doping nanoparticle in bioinspired adhesive surfaces to achieve highly efficient self-cleaning controllable by light signals. Notably, the adhesion of the 5% TDPDA-PDMS sample is ∼688.75% higher than that of the pure PDMS at the individual pillar level, which helps to explain the highly efficient self-cleaning mechanism. The sample surfaces (named TDPDA-PDMS) can efficiently absorb 808 nm wavelength of light and heat up from 25 °C to 80.9 °C in 3 min with NIR irradiation. The temperature rise causes significant reduction of adhesion, which results in outstanding self-cleaning rate of up to 55.8% within five steps. The exploration of the photoenabled switching mechanism with outstanding sensitivity may bring the biomimetic smart surfaces into a new dimension, rendering varied applications, e.g., in miniaturized climbing robot, artificial intelligence programmable manipulation/assembly/filtration, active self-cleaning solar panels, including high output sensors and devices in many engineering and biomedical frontiers.

The current preparation methods of carbon quantum dots (CDs) involve many reaction parameters, which leads to many possibilities in the synthesis processes and high uncertainty of the resultant production performance. Recently, machine learning (ML) methods have shown great potential in correlating the selected features in many applications, which can help understand the relevant structure-function relationships of CDs and discover better synthesis recipes as well. In this work, we employ the ML approach to guide the blue CD synthesis in microwave systems. After optimizing the synthesis parameters and conditions, the quantum yield (QY) increases to about 200% higher than the average value of the prepared samples without ML guidance. The obtained CDs are applied as fluorescent probes to monitor hydrogen peroxide (H

A model-based framework is presented to predict monoclonal antibody (mAb) pharmacokinetics (PK) in humans based on

There is a high demand for hydrogels with multifunctional performance (a combination of adhesive, mechanical, and electrical properties) in biological, tissue engineering, robotics, and smart device applications. However, a majority of existing hydrogels are relatively rigid and brittle, with limited stretchability; this hinders their application in the emerging field of flexible devices. In this study, cheap and abundant potato residues were used with polyacrylamide (PAM) to fabricate a multifunctional hydrogel, and chitosan was used for the design of a three-dimentional (3D) network-structured hydrogel. The as-prepared hydrogels exhibited excellent stretchability, with an extension exceeding 900% and a recovery degree of over 99%. Due to the combination of physical and chemical cross-linking properties and the introduction of dopamine, the designed hydrogel exhibits a remarkable self-healing ability (80% mechanical recovery in 2 h), high tensile strength (0.75 MPa), and ultra-stretchability (900%). The resultant products offer superior properties compared to those of previously reported tough and self-healing hydrogels for wound adhesion. Chitosan and potato residues were used as scaffold materials for the hydrogels with excellent mechanical properties. In addition, in vitro experiments show that these hydrogels feature excellent antibacterial properties, effectively hindering the reproduction of bacteria. Moreover, the ternary hydrogel can act as a strain sensor with high sensitivity and a gauge factor of 1.6. The proposed strategy is expected to serve as a reference for the development of green and recyclable conductive polymers to fabricate hydrogels. The proposed hydrogel can also act as a suitable strain sensor for bio-friendly devices such as smart wearable electronic devices and/or for health monitoring.

Geckos have the extraordinary ability to adhere and move across varied surfaces, while keeping their tiny high-aspect-ratio foot-hairs intact for thousands of attachment-detachment cycles. Inspired...

The high diffusion rate of sulfur with respect to metal oxide creates precursors that deviate from the stoichiometric ratio, leading to poor growth controllability and defects in the as-grown transition metal dichalcogenides (TMDCs). The introduction of a sulfur precursor with a high melting point is a hopeful strategy to solve these problems. Here, we first introduce sodium sulfate (Na2SO4) as a sulfur precursor, which plays roles in tuning diffusion of source precursors and balancing their mass flux based on the temperature-confined decomposition of Na2SO4. We deduced the specific growth process by characterizing the composition of intermediates; the results show that emissions of sulfur and metal sources were synchronously released and spanning the entire growth stage. This temperature-controlled source-feeding system reduced the diffusion gap between sulfur and metal, which promoted a faster kinetics for reactions. Moreover, this method has the wide applicability for producing other TMDCs.

Designing effective catalysts by controlling morphology and structure is key to improving the energy efficiency of fuel cells. A good understanding of the effects of specific structures on electrocatalytic activity, selectivity, and stability is needed. Here, we propose a facile method to synthesize PtCu bimetallic nanostructures with controllable compositions by using Cu nanowires as a template and ascorbic acid as a reductant. A further annealing process provided the alloy PtCu with tunable crystal structures. The combination of distinct structures with tunable compositions in the form of PtCu nanowires provides plenty of information for better understanding the reaction mechanism during catalysis. HClO4 cyclic voltammetry (CV) tests confirmed that various phase transformations occurred in bimetallic and alloy samples, affecting morphology and unit cell structures. Under a bifunctional synergistic effect and the influence of the insertion of a second metal, the two series of structures show superior performance toward methanol electrooxidation. Typically, the post-product alloy A-Pt14Cu86 with a cubic structure (a = 3.702 A) has better methanol oxidation reaction (MOR) catalysis performance. Density functional theory (DFT) calculations were performed to determine an optimal pathway using the Gibbs free energy and to verify the dependence of the electrocatalytic performance on the lattice structure via overpotential changes. Bimetallic PtCu has high CO tolerance, maintaining high stability. This work provides an approach for the systematic design of novel catalysts and the exploration of electrocatalytic mechanisms for fuel cells and other related applications.

Countless organisms in nature have adapted high-aspect-ratio micro-/nano-fibrillar arrays on their functional surfaces for achieving special and often optimized functionalities using earthly abundant materials. At the core of nanoscience and nanotechnology, rationally mimicking nature offers a promising route to create multifunctional superstructures that capture organisms and biological materials’ intriguing responsive and self-adjusting properties. Prior work has demonstrated that hierarchical vertically aligned multi-walled carbon nanotube (VA-MCNT) arrays can achieve ten folds of adhesive force comparing to the fibrillar structures of the gecko toe pads. However, little is known with regard to their wettability at the ultimate atomistic level, and how this may influence the adhesive performance and/or self-cleaning capabilities, despite water condensation and bridging are common phenomena at this length scale. In present study, molecular dynamics (MD) simulations were performed using Large-Scale Atomic / Molecular Massively Parallel Simulator (LAMMPS). Results indicate that commonly believed hydrophobic defect free CNTs (i.e., carbon sp2 hybridization without any dangling bonds) become super-hydrophilic at this length/temporal scale. The critical factors that influence the number of H-Bonds in water are: i) tube-tube spacing; and ii) shape/size and position of the water nanodroplet; and iii) how many droplets exists and how many nanotubes are bridged by the droplets. Chirality has little effect on the water interfacial behaviors. Future work will focus on the effect of water condensation and bridging on the adhesive and self-cleaning properties of carbon-based bio-inspired fibrillar dry adhesives considering defects and saline water.

Self-cleaning surfaces are desirable in many engineering applications where low energy consumption, reusability and sustainability are of the biggest concerns. Inspired by the gecko’s unique ‘dry self-cleaning’ hierarchical structures. Here we fabricated artificial Fe 3 O 4 /PDMS composites that show robust self-cleaning capabilities. The enhanced adhesion performance is attributable to the decrease of PDMS polymerization degree and the load transfer between PDMS matrix and Fe 3 O 4 magnetic particles. The self-cleaning surfaces showed up to 24.3% self-cleaning rate with as few as 4 steps. Simulation result indicated that the changing of cross linking between Fe 3 O 4 and PDMS is the main reason for the enhanced self-cleaning surfaces. This work reveals an alternative route of making high-performance self-cleaning smart surfaces that are applicable in the textile industry, robotic locomotion/gripping technology, outer-space explorations and tissue engineering.

Shape engineering plays a crucial role in the application of two-dimensional (2D) layered metal dichalcogenide (LMD) crystalline materials in terms of physical and chemical property modulation. How...

Fibroblast growth factor 21 (FGF21) serves as an essential biomarker for early detection and diagnosis of nonalcoholic fatty liver disease (NAFLD). It has received a great deal of attention recently in efforts to develop an accurate and effective method for detecting low levels of FGF21 in complex biological settings. Herein, we demonstrate a label-free, simple and high-sensitive field-effect transistor (FET) biosensor for FGF21 detection in a nonaqueous environment, directly utilizing two-dimensional molybdenum disulfide (MoS2) without additional absorption layers. By immobilizing anti-FGF21 on MoS2 surface, this biosensor can achieve the detection of trace FGF21 at less than 10 fg mL−1. High consistency and satisfactory reproducibility were demonstrated through multiple sets of parallel experiments for the MoS2 FETs. Furthermore, the biosensor has great sensitivity to detect the target FGF21 in complex serum samples, which demonstrates its great potential application in disease diagnosis of NAFLD. Overall, this study shows that thin-layered transition-metal dichalcogenides (TMDs) can be used as a potential alternative platform for developing novel electrical biosensors with high sensitivity and selectivity.

Present study reports a controllable phase transformation of nickel (Ni) from amorphous to cubic crystal structures on tungsten (W) substrate by electrodeposition. X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy and energy dispersive spectroscopy were used to characterize the microstructure, micro-constituents and surface morphology of as-prepared Ni. The microstructure of Ni was strongly affected by the applied overpotential and deposition time. It is demonstrated that by controlling these two parameters either amorphous or cubic crystal structure of Ni on the W substrate could be obtained. The crystallization mechanism is discussed based on Gibbs crystal growth theory and Ostwald’s rule. It is concluded that W substrate, acting as a heat sink, can effectively promote the thermal stability of amorphous Ni, based on the data from differential scanning calorimetry and Kissinger’s model. This work contributes to the elucidation of the crystallization mechanism of Ni on W powder substrates, and proves that, better than alloying with other elements, incorporating powder substrates will significantly improve the crystallization temperature, hence the thermostability of amorphous Ni.

Substitutional doping has been proven to be an effective route to engineer band gap, transport characteristics, and magnetism in transition metal dichalcogenides. Herein, we demonstrate substitutio...

Two-dimensional layered molybdenum disulfide (MoS2) is a promising catalyst for hydrogen evolution reaction (HER), and a good replacement for platinum (Pt) in elelctrochemical water splitting. Most transition metal dichalcogenides (TMDs) show excellent catalytic activity, which stems from their active sites located along the edges. However, small density of the active sites in the basal plane, largely limits TMDs performance. To enhance the HER catalysis activity of MoS2, we developed an efficient and scalable approach to significantly increase the overall electrochemically active sites using mild sodium hypochlorite (NaClO) solution anisotropic etching. The effect is further enhanced by oxygen-plasma pretreatment of the material, which - upon chemical etching - leads to highly porous and highly reactive structure. The resulting chemically activated MoS2 (ca-MoS2) was systematically characterized and optimized. The optimized ca-MoS2 powder exhibits enhanced HER performance with an overpotential of 0.34 V at a current density of 0.5 mA cm−2 in this experiment due to the increasing active sites, and the Tafel slope also smaller than other samples. This chemical etching method provides new ways to design atomic structure modification, including controlling layered TMD electrochemical property and new type of transistor fabrication.

Glucose effectiveness, defined as the ability of glucose itself to increase glucose utilization and inhibit hepatic glucose production, is an important mechanism maintaining normoglycemia. We conducted a minimal modeling analysis of glucose effectiveness at zero insulin (GEZI) using intravenous glucose tolerance test data from subjects with type 2 diabetes (T2D, n=154) and non-diabetic (ND) subjects (n=343). A hierarchical statistical analysis was performed, which provided a formal mechanism for pooling the data from all study subjects, to yield a single composite population model that quantifies the role of subject specific characteristics such as weight, height, age, sex, and glucose tolerance. Based on the resulting composite population model, GEZI was reduced from 0.021 min–1 (standard error – 0.00078 min–1) in the ND population to 0.011 min–1 (standard error – 0.00045 min–1) in T2D. The resulting model was also employed to calculate the proportion of the non–insulin-dependent net glucose uptake in each subject receiving an intravenous glucose load. Based on individual parameter estimates, the fraction of total glucose disposal independent of insulin was 72.8% ± 12.0% in the 238 ND subjects over the course of the experiment, indicating the major contribution to the whole-body glucose clearance under non-diabetic conditions. This fraction was significantly reduced to 48.8% ± 16.9% in the 30 T2D subjects, although still accounting for approximately half of the total in the T2D population based on our modeling analysis. Given the potential application of glucose effectiveness as a predictor of glucose intolerance and as a potential therapeutic target for treating diabetes, more investigations of glucose effectiveness in other disease conditions can be conducted using the hierarchical modeling framework reported herein.

In this study, apple pectin (AP) and tomato pectin (TP) were demonstrated to be a high-ester (74.8%) polysaccharide with the weight-average molecular weight (

Oral plaque biofilms are highly resilient microbial assemblies that are challenging to eradicate. Herein, we describe the synthesis and study of pH-positive, doxycycline (DOX)-loaded nanocarriers to combat pathogenic biofilms. The mixed shell-core nanoparticles consisted of quaternary ammonium chitosan (TMC) as a positively charged section, which targeted nanoparticles to negatively charged biofilm surfaces. In addition liposomes were used as a DOX loading tool to eradicate the multidrug-resistant biofilm. In a drug release test, DOX release was pH-dependent with t1/2 = 0.75 h and 2.3 h for release at pH 4.5 and 6.8, respectively. Furthermore, TMC-Lip-DOX NPs could adhere to the biofilm and efficiently remove the biofilm from the hydroxyapatite (HA) surface. Furthermore, TMC-Lip-DOX NPs had biocomaptible properties and were non-toxic to MC3T3-E1 cells. This constitutes a highly effective pathway to control oral plaque biofilms and has a good potential use for dental biofilm therapies.

Growth of large-area, uniform, and high-quality monolayer transition-metal dichalcogenides (TMDs) for practical and industrial applications remains a long-standing challenge. The present study demonstrates a modified predeposited chemical vapor deposition (CVD) process by employing an annealing procedure before sulfurization, which helps in achieving large-area, highly uniform, and high-quality TMDs on various substrates. The annealing procedure resulted in a molten liquid state of the precursors in the CVD process, which not only facilitated a uniform redistribution of the precursor on the substrate (avoid the aggregation) because of the uniform redistribution of the liquid precursor on the substrate but more importantly avoided the undesired multilayer growth via the self-limited lateral supply precursors mechanism. A 2 in. uniform and continuous monolayer WS2 film has been synthesized on the SiO2/Si substrate. Moreover, uniform monolayer WS2 single crystals can be prepared on more general and various substrates including sapphire, mica, quartz, and Si3N4 using the same growth procedure. Besides, this growth mechanism can be generalized to synthesize other monolayer TMDs such as MoS2 and MoS2/WS2 heterostructures. Hence, the present method provides a generalized attractive strategy to grow large-area, uniform, single-layer two-dimensional (2D) materials. This study has significant implications in the advancement of batch production of various 2D-material-based devices for industrial and commercial applications.

Hydraulic fracturing has become one of the most popular techniques for exploring sustainable energy sources. However, friction is associated with the entire fracturing process, presenting significant challenges for development. Facing the huge friction challenges, this review is elaborated in the following three aspects: (1) the fundamentals of hydraulic fracturing, including three aspects of rock fracture mechanism, fracturing fluid, and proppant; (2) the friction challenges in hydraulic fracturing, which mainly exist in friction along the path and friction near wellbore; (3) hydraulic fracturing drag reduction technologies, which are considered proppant segment plug, fracturing fluid viscosity enhancement, and proppant surface modification technologies. Therefore, we should not only understand the challenges in hydraulic fracturing but also know how to mitigate them. Additionally, we call for a strong focus on environmentally friendly, green friction-reducing technologies for oil and gas fields in the future development of the fracturing industry.

Hongshaquan coal (HSQ), a kind of high-alkali and rich-iron coal, is burned in a 20 MW liquid slagging cyclone furnace. The migration and transformation characteristics of elements are examined. The deposition probe and oil cooling circulation system are used to investigate the ash deposition characteristics of HSQ. In addition, the microscopic morphology, crystal structure and chemical composition of the slag are studied to explain the effect of element migration on ash deposition and slag. The results show that the growth process of deposition on probe 1 can be divided into four stages. The final stable relative heat flux of probe 1 and probe 2 is 0.585 and 0.85, respectively. The average concentration of Na2O in ash is 4.53%. Na, K, Ca, Mg and S are enriched in the low temperature area of the boiler to form sulfate which leads to the agglomeration of ash particles. The main mineral phases of the slag are silicates and iron-containing compounds. The average concentration of Fe2O3 in the slag sample is 36.73%. Iron will be enriched in the slag and form a low-temperature eutectic with the silicon-calcium-magnesium–aluminum system to reduce the melting point of the ash. The granulated slag has a lower degree of crystallinity and is closer to the characteristics of glassy slag, which is due to the low content of Na2O, CaO and high silicon-to-aluminum ratio in the ash.

In this work, a composite sponge was produced by physically mixing hydroxybutyl chitosan with chitosan to form a porous spongy material through vacuum freeze-drying. Hydrophilic and macroporous composite hydroxybutyl chitosan sponge was developed via the incorporation of chitosan into hydroxybutyl chitosan. The composite sponge showed higher porosity (about 85%), greater water absorption (about 25 times), better softness and lower blood-clotting index (BCI) than those of chitosan sponge and hydroxybutyl chitosan sponge. The composite sponge with good hydrophilic could absorb the moisture in the blood to increase blood concentration and viscosity, and become a semi-swelling viscous colloid to clog the capillaries. Cytocompatibility tests with L929 cells and HUVEC cells demonstrated that composite sponge were no cytotoxicity, and could promote the growth of fibroblasts. It made up for the shortcomings of hydroxybutyl chitosan with unfavorable antibacterial effect to achieve a higher level of antibacterial (>99.99% reduction). Eventually, the vivo evaluations in Sprague-Dawley rats revealed that epithelial cells attached to the composite sponge and penetrated into the interior, in addition to this, it was also proved that the composite sponge (HC-1) had a better ability to promote wound healing and helped for faster formation of skin glands and re-epithelialization. The obtained data encourage the use of this composite sponge for wound dressings.

The hemostatic properties of surface modified chitosan nonwoven had been investigated. The succinyl groups, carboxymethyl groups and quaternary ammonium groups were introduced into the surface of chitosan nonwoven (obtained NSCS, CMCS and TMCS nonwoven, respectively). For blood clotting, absorbance value (0.105±0.03) of NSCS1 nonwoven was the smallest (CS 0.307±0.002, NSCS2 0.148±0.002, CMCS1 0.195±0.02, CMCS2 0.233±0.001, TMCS1 0.191±0.002, TMCS2 0.345±0.002), which indicated the stronger hemostatic potential. For platelet aggregation, adenosine diphosphate agonist was added to induce the nonwoven to adhered platelets. The aggregation of platelet with TMCS2 nonwoven was highest (10.97±0.16%). Further research of blood coagulation mechanism was discussed, which indicated NSCS and CMCS nonwoven could activate the intrinsic pathway of coagulation to accelerate blood coagulation. NSCS1 nonwoven showed the shortest hemostatic time (147±3.7s) and the lowest blood loss (0.23±0.05g) in a rabbit ear artery injury model. These results demonstrated that these surface modified chitosan nonwoven dressings could use as a promising hemostatic intervention, especially NSCS nonwoven dressing.

Gecko lizards have a remarkable climbing capability that enables them to adapt to a variety of environments. Although the hierarchical structures and adhesion mechanism of gecko feet have been studied extensively, there lacks a fundamental understanding of adhesion at relatively low temperature, in particular below icing point. Here, we study the adhesion forces of nanoscale gecko spatulae and setae on multiple surfaces in a broad range of temperature from 40 to -10°C. Results demonstrate that the adhesion force of a single gecko spatula on a mica substrate at -10 °C increased by ∼100% compared with that at room temperature. The adhesion and friction forces of a single seta also display similar trends. It is found that hydrogen bonds play a key role in the temperature-induced tunable adhesion. Emulating gecko feet, we have fabricated fibrillary adhesive surfaces and tested them under different environments. Like their biological counterparts, regulating temperature can tune their adhesion and self-cleaning capacity. This study shed lights on the adhesion mechanism of gecko at low temperature, and provides a base for the design of new generations of smart tires, climbing robots and/or biomedical devices that would perform robustly under extreme environments.

The Ce 3 + -doped YAG crystal has drawn considerable interest because of its important application in the white light-emitting diodes. However, the fundamental understanding of its microstructure is still lacking. In this work, the structural evolution and electronic properties of Ce 3 + -doped YAG crystal are systematically studied on the basis of the density functional theory (DFT) as well as Crystal structure Analysis by Particle Swarm Optimization (CALYPSO) method. A novel stable phase with cage-like structure and C 222 space group of Ce 3 + -doped YAG crystal has been reported. The calculations of the electronic band structure indicate that the Ce 3 + -doped YAG possesses a conductive character because the Fermi level is crossed through by the conduction band. By analyzing the electronic density of states (DOS), we conclude that the reason of the elimination of the insulated character can be attributed to the impurity Ce 3 + . The bond character between the Ce-O and Y-O are identified by the calculation of the electron localization function (ELF). These results can offer significant information for exploring new rare-earth doped laser materials and also provide useful insights to elucidate some experimental phenomena.

Rare-earth neodymium ions (Nd3+) doped CaTiO3 crystal shows excellent light-emitting properties which give rise to the development of new-generation laser devices. However, the structural evolutions of the trivalent Nd3+ doped CaTiO3 (CaTiO3:Nd) crystal are still not clear. Herein, we report a systematic first-principles study on the geometrical structures and electronic properties of CaTiO3:Nd. Based on the crystal structure analysis by particle swarm optimization (CALYPSO) method combined with density functional theory, we uncover a novel layered grid structure with Pm space group. The Ca2+ ion in the host crystal is replaced by the Nd3+ ion. The simulated XRD spectrums match fairly well with the experimental data, which demonstrating the validity of the obtained ground state structure. The calculated band structures manifest that the conduction band pass through the Fermi level, suggesting a conductive character of CaTiO3:Nd. The results of density of states (DOS) demonstrate that the impurity Nd3+ ions can trigger a phase transition of CaTiO3 from semiconductor to conductor. The analysis of electron localization function (ELF) for CaTiO3:Nd indicates that the interaction between Ca-O is mainly ionic bond. These results could provide significant insights for exploring new laser materials.

The chitosan based on purified regeneration could be dissolved in 6wt% aqueous NaOH without freeze-thawing cycles and acetylation processing, and such a solution system was effective and different from other dissolving methods Upon heating, a tough hydrogel was constructed from the chitosan (purified regeneration) alkaline solution. The results of XRD, TEM, SEM and rheology analysis proved that chitosan easily aggregated in the solution and formed a nanofibers network to gelate at elevated temperature and concentration. The merely chitosan hydrogel had a uniform network structure and its (5wt%) compressive fracture stress could reach 0.2MPa. Furthermore, the hydrogels exhibited excellent biodegradability, blood compatibility and cellular compatibility. Therefore, the tough chitosan hydrogels may have a wide range of applications in biomedicine.

The effective combination of drugs promoting antiangiogenesis and apoptosis effects has proven to be a promising collaborative tumor antidote; and the codelivery of small interfering RNA (siRNA) and chemotherapy agents within one efficient vehicle has gained more attention over single regimen administration. Herein, vascular endothelial growth factor specific siRNA (siVEGF) and paclitaxel (PTX) were introduced as therapeutic companions and coencapsulated into naturally mimic high-density lipoproteins (rHDL/siVEGF-PTX), so that various mechanisms of treatment can occur simultaneously. The terminal nanoparticles share capacity of specific-targeting to tumor cells overexpressed scavenger receptor class B type I (SR-BI) and deliver siVEGF and PTX into cytoplasm by a nonendocytosis mechanism. By exchanging HDL core lipids with hydrophobic therapeutics, rHDL/siVEGF-PTX possessed particle size of ∼160 nm, surface potential of ∼-20 mV, and desirable long-term storage stability. In vitro results confirmed that the parallel activity of siVEGF and PTX displayed enhanced anticancer efficacy. The half-maximal inhibitory concentration (IC

The off-target distribution of anticancer nanoparticles to fibroblasts creates a barrier to the effective treatment of desmoplastic tumors. However, we hypothesized that this nanoparticle detriment might be exploited to target the expression of secreted cytotoxic proteins from tumor-associated fibroblasts (TAF) as an anticancer strategy. In addressing this hypothesis, plasmids encoding the secretable TNF-related factor sTRAIL were loaded into lipid-coated protamine DNA complexes and administered by infusion in a murine xenograft model of human desmoplastic bladder carcinoma. Three doses were sufficient to generate approximately 70% of TAFs as sTRAIL-producing cells. sTRAIL triggered apoptosis in tumor cell nests adjacent to TAFs. Furthermore, it reverted residual fibroblasts to a quiescent state due to insufficient activation, further compromising tumor growth and remodeling the microenvironment to favor second-wave nanotherapy. We confirmed the efficacy of this strategy in an orthotopic xenograft model of human pancreatic cancer, where the desmoplastic stroma is well known to be a major barrier to the delivery of therapeutic nanoparticles. Collectively, our results offer a proof of concept for the use of nanoparticles to modify TAFs as an effective strategy to treat desmoplastic cancers. Cancer Res; 77(3); 719–31. ©2016 AACR.

Cutaneous chronic wounds are characterized by impaired wound healing which may lead to infection and even amputation. To surmount this problem, we developed a chitin whisker (CW)/carboxymethyl chitosan nanoparticles (CMCS NPs)/thermosensitive hydroxybutyl chitosan (HBC) composite hydrogel (CW/NPs/HBC-HG) as a wound dressing for treating chronic wounds. Upon introduction of CWs, the composite hydrogel exhibited a significant decrease in gelation temperature and enhanced mechanical properties. The storage modulus (G') of the CW/NPs/HBC-HG was 3.6 times that of the NPs/HBC-HG at 37 °C and the ex vivo rat skin test also showed that the mechanical properties were significantly improved. Linezolid, a wide-spectrum antibiotic, was dissolved directly in the water phase of the composite hydrogel, and the antibacterial activity of the composite hydrogel against Escherichia coli and Staphylococcus aureus was up to 99% until 7 days. When recombinant human epidermal growth factor (rhEGF) was encapsulated into the NPs, the CW/NPs/HBC-HG offered prolonged cell proliferation activity up to 5 days. More importantly, the in vivo chronic wound healing model evaluation in diabetic rats revealed that the CW/NPs/HBC-HG dressing promoted wound healing and accelerated reepithelialization, collagen deposition and angiogenesis. These findings demonstrated that CW/NPs/HBC-HG is a promising dressing for chronic wounds.

Shape engineering plays a crucial role in the application of two-dimensional (2D) layered metal dichalcogenide (LMD) crystalline materials in terms of physical and chemical property modulation. However, controllable growth of 1T phase tin disulfide (SnS