bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fluorination Enhances Serum Stability of Bioreducible Poly(amido amine) Polyplexes and Enables Efficient Intravenous siRNA Delivery
Authors: Chen Gang , Wang Kaikai , Wang Yixin , Wu Pengkai , Sun Minjie , Oupický David 
Published: December 2017

AbstractThe use of small interfering RNA (siRNA) in cancer treatment has been limited by the lack of effective systemic delivery methods. Although synthetic polycations have been widely explored in siRNA delivery, polycation/siRNA polyplexes often suffer from insufficient stability in vivo. Here, rationally designed siRNA delivery systems that meet the requirements for systemic siRNA delivery to distant tumors are reported. The hypothesis that modular design of delivery systems based on poly(amido amine)s that combine fluorination for systemic stability with bioreducibility for easy intracellular siRNA release, and PEGylation for improved safety and colloidal stability will overcome problems with contradicting siRNA delivery demands is tested. PEGylated, fluorinated, and bioreducible copolymers (PEG‐PCD‐F) with different degree of fluorination are thus synthesized. The fluorinated copolymers readily formed polyplexes with siRNA and achieved greatly improved gene silencing efficacy in multiple cell lines in vitro when compared with nonfluorinated controls. The results show fluorination‐induced enhancement of stability, cellular uptake, and endosomal escape of the polyplexes, while exhibiting efficient siRNA release in reducing intracellular environment. PEG‐PCD‐F polyplexes with siRNA against Bcl2 inhibit breast tumor growth following systemic intravenous administration. The results provide strong evidence of successful combination of bioreducibility with fluorination and PEGylation to achieve systemic siRNA polyplex delivery.
A Fluorescent Biofunctional DNA Hydrogel Prepared by Enzymatic Polymerization
Authors: Geng Jinhui , Yao Chi , Kou Xiaohong , Tang Jianpu , Luo Dan , Yang Dayong 
Published: December 2017

AbstractDNA has arisen as a promising building material for the construction of hydrogels owing to its unique properties such as designability and biocompatibility. All‐DNA hydrogels with only DNA molecules may have limited applications; hence a composite DNA hydrogel with multifunctional moieties is highly desired to cater for specific applications. Herein, a multifunctional DNA hydrogel is created by incorporating DNA with silver nanoclusters (AgNCs), in which AgNCs render the hydrogel simultaneously with fluorescent and antibacterial functions. A circular DNA is rationally designed, which allows for the elongation of DNA chain via an enzymatic polymerization as well as the formation of AgNCs onto DNA scaffolds. The resultant hybrid DNA hydrogel not only shows distinctive morphology and mechanical properties, but also exhibits fluorescent and antibacterial functions. These characteristics, along with its biocompatibility, will allow the hydrogel to be suitable for a variety of potential biomedical applications such as tissue engineering, wound dressing, biosensing, and bioimaging.
Current Approaches to Bone Tissue Engineering: The Interface between Biology and Engineering
Authors: Li Jiao Jiao , Ebied Mohamed , Xu Jen , Zreiqat Hala 
Published: December 2017

AbstractThe successful regeneration of bone tissue to replace areas of bone loss in large defects or at load‐bearing sites remains a significant clinical challenge. Over the past few decades, major progress is achieved in the field of bone tissue engineering to provide alternative therapies, particularly through approaches that are at the interface of biology and engineering. To satisfy the diverse regenerative requirements of bone tissue, the field moves toward highly integrated approaches incorporating the knowledge and techniques from multiple disciplines, and typically involves the use of biomaterials as an essential element for supporting or inducing bone regeneration. This review summarizes the types of approaches currently used in bone tissue engineering, beginning with those primarily based on biology or engineering, and moving into integrated approaches in the areas of biomaterial developments, biomimetic design, and scalable methods for treating large or load‐bearing bone defects, while highlighting potential areas for collaboration and providing an outlook on future developments.
Selective Cell Penetrating Peptide‐Functionalized Polymersomes Mediate Efficient and Targeted Delivery of Methotrexate Disodium to Human Lung Cancer In Vivo
Authors: Yang Weijing , Xia Yifeng , Fang Yuan , Meng Fenghua , Zhang Jian , Cheng Ru , Deng Chao , Zhong Zhiyuan 
Published: December 2017

AbstractIt is a long challenge to develop nanomedicines that simultaneously possess tumor cell selectivity and penetration functions. Here, it is reported that selective cell penetrating peptide (RLWMRWYSPRTRAYGC)‐functionalized polymersomes (SCPP‐PS) mediate efficient and targeted delivery of methotrexate disodium (MTX) to human lung cancer in vivo. SCPP‐PS with an SCPP density of 18.7% is self‐crosslinked, has a small size (63–65 nm), and high MTX loading (up to 19.4 wt%), shows selective uptake and fast penetration into A549 lung cancer cells, and efficiently releases MTX intracellularly. Interestingly, MTX‐loaded SCPP‐PS (MTX‐SCPP‐PS) displays much lower IC50 than those of MTX‐PS and free MTX. Installing SCPP to polymersomes has no detrimental effect to their long blood circulation time but significantly increases drug accumulation in A549 tumor (5.3% injected dose per gram at 8 h post injection). Remarkably, SCPP‐PS exhibits deep penetration in to A549 tumors. MTX‐SCPP‐PS completely inhibits tumor progression and significantly improves survival rates in mice bearing A549 lung tumor xenografts as compared to MTX‐PS and free MTX groups (median survival time: 75 vs 45 and 38 d, respectively), without causing noticeable adverse effects. These results highlight that functionalization of nanomedicines with SCPP is a feasible strategy to achieve efficient and targeted tumor therapy.
Thermoresponsive Supramolecular Chemotherapy by “V”‐Shaped Armed β‐Cyclodextrin Star Polymer to Overcome Drug Resistance
Authors: Fan Xiaoshan , Cheng Hongwei , Wang Xiaoyuan , Ye Enyi , Loh Xian Jun , Wu Yun‐Long , Li Zibiao 
Published: December 2017

AbstractPump mediated drug efflux is the key reason to result in the failure of chemotherapy. Herein, a novel star polymer β‐CD‐v‐(PEG‐β‐PNIPAAm)7 consisting of a β‐CD core, grafted with thermo‐responsive poly(N‐isopropylacrylamide) (PNIPAAm) and biocompatible poly(ethylene glycol) (PEG) in the multiple “V”‐shaped arms is designed and further fabricated into supramolecular nanocarriers for drug resistant cancer therapy. The star polymer could encapsulate chemotherapeutics between β‐cyclodextrin and anti‐cancer drug via inclusion complex (IC). Furthermore, the temperature induced chain association of PNIPAAm segments facilitated the IC to form supramolecular nanoparticles at 37 °C, whereas the presence of PEG impart great stability to the self‐assemblies. When incubated with MDR‐1 membrane pump regulated drug resistant tumor cells, much higher and faster cellular uptake of the supramolecular nanoparticles were detected, and the enhanced intracellular retention of drugs could lead to significant inhibition of cell growth. Further in vivo evaluation showed high therapeutic efficacy in suppressing drug resistant tumor growth without a significant impact on the normal functions of main organs. This work signifies thermo‐responsive supramolecular chemotherapy is promising in combating pump mediated drug resistance in both in vitro and in vivo models, which may be encouraging for the advanced drug delivery platform design to overcome drug resistant cancer.
Utilization of Peroxide Reduction Reaction at Air–Liquid–Solid Joint Interfaces for Reliable Sensing System Construction
Authors: Song Zhiqian , Xu Chenlong , Sheng Xia , Feng Xinjian , Jiang Lei 
Published: December 2017

AbstractThe utilization of hydrogen peroxide (H2O2) cathodic reaction is an ideal approach to develop reliable biosensors that are immune to interferences arising from oxidizable endogenous/exogenous species in biological solutions. However, practical application of such a detection scheme is limited due to the significantly fluctuating oxygen levels in solutions, as oxygen can be reduced at similar potentials. Herein, this limitation is addressed by developing a novel electrode system with superhydrophobicity‐mediated air–liquid–solid joint interfaces, which allows the rapid and continuous transport of oxygen from the air phase to the electrode surface and provides a fixed interfacial oxygen concentration. Using cathodic measurement of the enzymatic product H2O2, the sensing platform is applied to detect glucose, a model analyte, achieving a remarkably high selectivity (≈2% signal modulation due to common biologic interferents), sensitivity (18.56 µA cm−2 mm−1), and a dynamic linear range up to 80 × 10−3m. The utility of H2O2 reduction reaction at triphase interface to achieve reliable sensing platforms is general, and hence has broad potential in the fields of medical research, clinical diagnosis, and environmental analysis.
Combined Effect of the Microstructure and Underlying Surface Curvature on the Performance of Biomimetic Adhesives
Authors: Kizilkan Emre , Gorb Stanislav N. 
Published: December 2017

AbstractThe importance of the geometry of the micro‐/nanosized attachment elements for adhesive characteristics of gecko‐inspired microstructured surfaces has been comprehensively discussed in recent years. Due to the complex hierarchical structure of these systems, they possess a broad range of adhesion control capabilities by either passive or active adaptability of their underlying structures to the specific substrate and/or behavioral situation. Here, the influence of macroscopic geometry of backing layers hosting biomimetic microstructured surfaces is examined. The flat, convex, and concave macroscopic configurations of the bioinspired microstructured adhesive surfaces are examined on their adhesive performance under varying degrees of curvature and preloads. Microstructured surfaces demonstrated an adhesion range differing by up to a factor of 2 alone through varying backing layer configuration. The results can aid in understanding the influence of curvature geometry on hierarchically structured adhesive systems and the implementation of biomimetic structured surfaces in applications such as robots and grippers optimized for different sized objects.
3D‐Printed Biomimetic Super‐Hydrophobic Structure for Microdroplet Manipulation and Oil/Water Separation
Authors: Yang Yang , Li Xiangjia , Zheng Xuan , Chen Zeyu , Zhou Qifa , Chen Yong 
Published: December 2017

AbstractBiomimetic functional surfaces are attracting increasing attention for various technological applications, especially the superhydrophobic surfaces inspired by plant leaves. However, the replication of the complex hierarchical microstructures is limited by the traditional fabrication techniques. In this paper, superhydrophobic micro‐scale artificial hairs with eggbeater heads inspired by Salvinia molesta leaf was fabricated by the Immersed surface accumulation three dimensional (3D) printing process. Multi‐walled carbon nanotubes were added to the photocurable resins to enhance the surface roughness and mechanical strength of the microstructures. The 3D printed eggbeater surface reveals interesting properties in terms of superhydrophobilicity and petal effect. The results show that a hydrophilic material can macroscopically behave as hydrophobic if a surface has proper microstructured features. The controllable adhesive force (from 23 μN to 55 μN) can be easily tuned with different number of eggbeater arms for potential applications such as micro hand for droplet manipulation. Furthermore, a new energy‐efficient oil/water separation solution based on our biomimetic structures was demonstrated. The results show that the 3D‐printed eggbeater structure could have numerous applications, including water droplet manipulation, 3D cell culture, micro reactor, oil spill clean‐up, and oil/water separation.
Wet‐Transfer of Freestanding Dense Colloidal Quantum Dot Films and Their Photonic Device Application
Authors: Han Changhyun , Jung Hyunho , Lee Jongho , Lee Myungjae , Park Yeonsang , Cho Kyung‐Sang , Jeon Heonsu 
Published: December 2017

AbstractA method of wet‐transferring a densely packed colloidal quantum dot (CQD) film is reported herein. Layers of poly(vinyl alcohol) (sacrificial layer) and poly(methyl methacrylate) (temporary mechanical support) are spin‐coated below and above the CQD film, respectively; the two layers are eventually removed, resulting in a single CQD film on an alien substrate. CQD films as large as 1 cm × 1 cm are transferred to any substrate, including flexible and prepatterned ones, with very little mechanical or optical damage. The wet‐transfer method can be repeated to form a CQD heterostructure. A CQD distributed feedback (DFB) laser is also demonstrated by transferring a thick CdSe‐based CQD layer (for both optical gain and waveguiding) on top of a surface grating structure. The resultant CQD structure exhibits a single‐mode DFB lasing action, with a high spontaneous emission factor (β ≈ 10−3), owing to a strong vertical mode confinement and smooth surface morphologies on both sides of the CQD waveguide layer.
Room‐Temperature Red–Green–Blue Whispering‐Gallery Mode Lasing and White‐Light Emission from Cesium Lead Halide Perovskite (CsPbX3, X = Cl, Br, I) Microstructures
Authors: Guo Pengfei , Hossain Mohammad Kamal , Shen Xia , Sun Haibin , Yang Wenchao , Liu Chaoping , Ho Chun Yuen , Kwok Cheuk Kai , Tsang Sai‐Wing , Luo Yongsong , Ho Johnny C. , Yu Kin Man 
Published: December 2017

AbstractWavelength‐tunable nano/microlasers are essential components for various highly integrated and multifunctional photonic devices. Based on the different band gap/composition of inorganic cesium lead halide perovskite materials, broad band light absorption and emission devices can be achieved. Herein, a vapor–liquid–solid route for growing cesium lead halide perovskite (CsPbX3, X = Cl, Br, I) microcrystal structures is demonstrated. These square‐shaped microstructures exhibit strong blue, green, and red photoluminescence, indicating that their band gaps can be engineered to cover the entire visible range. Optically pumped red–green–blue whispering‐gallery mode lasers based on the controlled composition of these microcrystals are successfully realized at room temperature. Moreover, rationally designed white‐light‐emitting chips with high brightness are fabricated utilizing these metal halide perovskite microstructures grown on sapphire. All these results evidently suggest a feasible route to the design of red–green–blue lasers and white‐light emitters for potential applications in full‐color displays as well as photonic devices.
Potassium Ion Assisted Synthesis of Organic–Inorganic Hybrid Perovskite Nanobelts for Stable and Flexible Photodetectors
Authors: Zhu Bai‐Sheng , He Zhen , Yao Ji‐Song , Chen Chen , Wang Kun‐Hua , Yao Hong‐Bin , Liu Jian‐Wei , Yu Shu‐Hong 
Published: December 2017

AbstractLow‐dimensional organic–inorganic hybrid perovskites with controllable morphologies are attractive for high‐performance optoelectronic devices. In particular, the 1D organic–inorganic hybrid perovskite nanowires/nanobelts are promising for flexible photodetectors due to high photoresponsivity and strain endurance capability. Herein, a novel and large‐scale synthesis of (C4H9NH3)2PbBr4 organic–inorganic hybrid perovskite nanobelt achieved by the potassium ions assisted controllable crystal growth during the precipitation process in solutions is reported. The obtained (C4H9NH3)2PbBr4 perovskite nanobelts exhibit high‐efficient photoluminescence and superior stability under ambient conditions. Furthermore, these nanobelts are used as photoresponsive materials to fabricate flexible photodetectors, which show much higher switching ratio than that of photodetectors based on (C4H9NH3)2PbBr4 microplatelets. Attractively, after repeated bending for 1000 times, the nanobelt‐based photodetector only shows less than 10% decay in switching ratio in contrast to at least 40% of switching ratio decay for the microplatelets‐based photodetector. The reported potassium ion assisted large‐scale synthesis of (C4H9NH3)2PbBr4 nanobelts paves a new avenue for the application of organic–inorganic hybrid perovskites in flexible optoelectronic devices.
Dynamically Tunable Deep Subwavelength High‐Order Anomalous Reflection Using Graphene Metasurfaces
Authors: Wang Chao , Liu Wenwei , Li Zhancheng , Cheng Hua , Li Zhi , Chen Shuqi , Tian Jianguo 
Published: December 2017

AbstractGraphene‐based metasurfaces have emerged as promising photoelectric devices that can dynamically control the behavior of electromagnetic waves. The high‐order anomalous reflection provides an additional degree of freedom in the field of photonic research. Here, a series of gradient graphene metasurfaces with high‐order modes to manipulate the wavefront of reflected light is proposed. By properly arranging the graphene nanostructures, 5‐order anomalous reflection and 15‐order high‐quality Laguerre–Gaussian beams are achieved. Furthermore, the efficiency of the metasurfaces is dynamically controlled by tuning the electrostatic gating to change the Fermi energy of graphene. This work offers a new idea for the development of tunable wavefront‐controlling devices and contributes to a wide range of applications in photonic systems.
Nanosizing Ammonia Borane with Nickel: A Path toward the Direct Hydrogen Release and Uptake of BNH Systems
Authors: Lai Qiwen , Rawal Aditya , Quadir Md Zakaria , Cazorla Claudio , Demirci Umit B. , Aguey‐Zinsou Kondo‐Francois 
Published: December 2017

AbstractAmmonia borane (AB), with one of the highest hydrogen content (19.6 mass%), has attracted much attention as a potential hydrogen storage material. However, its complex and multistep thermal decomposition process has left the idea that AB can only be an irreversible hydrogen storage material. Herein, we demonstrate the potential of a novel nanosizing strategy in overcoming current drawbacks. By (a) successfully restricting the particle size of AB to the nanoscale (≈50 nm), and (b) discreetly encapsulating the synthesised nanosized AB particles within a nickel (Ni) matrix, AB showed unforeseen hydrogen reversibility along its decomposition path. Owing to the catalytic effect of Ni and the embedment of AB with the Ni matrix, this nanosizing approach reduced the hydrogen release temperature, suppressed the melting of AB and the production of volatiles by‐products including diborane and borazine. But more remarkably, this approach enabled the reversible release and uptake of pure hydrogen at 200 °C and 6 MPa H2 pressure, only. Reversibility is thought to occur through an iminoborane oligomer resulting from the initial decomposition of the nanosized AB/Ni matrix. This result demonstrates for the first time the possibility of tailoring.
Multilayered Flexible Fibers with High Performance for Wearable Supercapacitor Applications
Authors: Garcia‐Torres Jose , Crean Carol 
Published: December 2017

AbstractMultilayered flexible fibers, consisting of carbon black–carbon nanotube fibers, manganese oxides, and conducting polymers, are fabricated for use as electrodes in supercapacitors. Carbon‐based fibers are initially prepared by wet‐spinning using carbon‐based nanomaterials (carbon black and carbon nanotubes) and chitosan as a matrix. Subsequent coatings with manganese oxides and conducting polymers form a multilayered structure. Different MnO2 crystalline structures (ε‐MnO2, γ‐MnO2) are grown onto the fiber by electrodeposition and different conducting polymers (polyethylenedioxythiophene and polypyrrole) used as a conductive wrapping. Each layer improves the performance of the fiber by adding different functionalities. While MnO2 improves the capacitance of the fiber, the presence of conducting polymers creates a conductive network increasing the capacitance further and conferring cycling stability. Capacitance values up 600 F g−1 and capacitance retention of 90% can be achieved with these multilayered hybrid fibers. A symmetric supercapacitor device, prepared from two hybrid fibers, shows no significant change in properties when the device is bent, demonstrating their potential in flexible electronic devices and wearable energy systems.
High‐Performance Activated Carbons Synthesized from Nanocellulose for CO2 Capture and Extremely Selective Removal of Volatile Organic Compounds
Authors: Xu Chao , Ruan Chang‐Qing , Li Yunxiang , Lindh Jonas , Strømme Maria 
Published: December 2017

AbstractA series of sustainable activated carbons (ACs) with large surface areas and tunable pore sizes is synthesized from Cladophora cellulose and its chemically modified derivatives in a one‐step physical carbonization/activation process. The molecular structure of the cellulose precursors and the carbonization/activation atmosphere (N2 or CO2) significantly influence the pore structure of the ACs. When using oxidized cellulose and its further cross‐linkages as the precursor, the ACs have a large volume of ultramicropores (pore diameter < 0.8 nm). Activation in CO2 results in ACs with surface areas up to 1241 m2 g−1. These ACs have a high CO2 uptake capacity (2.29 mmol g−1 at 0.15 bar, 5.52 mmol g−1 at 1 bar; 273 K) and a high CO2–over–N2 selectivity (42 at 273 K). In addition, the capacity of the ACs to adsorb vapors of volatile organic compounds (VOCs) is remarkable, with values up to 0.97 mmol g−1 at very low VOC concentrations (200 ppmv). The ACs have ultrahigh VOCs–over–N2 selectivity up to 9.35 × 103 at 293 K for 0.02 vol%/99.8 vol% of benzene/N2 mixture. It is anticipated that these ACs will be useful as sorbents for the postcombustion capture of CO2 and for indoor removal and direct air capture of various VOCs.
Hydrolytically Stable MOF in 3D‐Printed Structures
Authors: Halevi Oded , Tan Joel M. R. , Lee Pooi See , Magdassi Shlomo 
Published: December 2017

AbstractMetal–organic frameworks (MOFs) are a well‐developed field of materials, having a high potential for various applications such as gas storage, water purification, and catalysis. Despite the continuous discoveries of new MOFs, so far there are only a limited number of industrial applications, partially due to their low chemical stability and limited mechanical properties, as well as difficulties in integration within functional devices, Herein, a new approach is presented toward the fabrication of MOF‐based devices, utilizing direct 3D printing. By this method, 3D, flexible, and hydrolytically stable MOF‐embedded polymeric structures are fabricated. It is found that the adsorption capacity of the 3D‐printed MOF is retained, with significantly improved hydrolytic stability of the printed MOFs (copper benzene‐1,3,5‐tricarboxylate) compared to the MOF only. It is expected that applying 3D printing technologies, for the fabrication of functional MOF objects such as filters and matrices for columns and flow reactors, will open the way for utilization of this important class of materials.