bluuebunny/crossref_metadata_2025_split huggingface dataset:
Shape Transformable Strategies for Drug Delivery
Authors: Jia Wenfeng , Wang Yushan , Liu Rui , Yu Xiangrong , Gao Huile 
Published: February 2021

AbstractIn tumor therapy, nanodrug delivery systems have gained momentum in the last decade. However, its efficacy remains insufficient for clinical applications. The physical properties of nanoparticles, including size, shape, and surface characteristics, can strongly affect the delivery efficacy. Ironically, research on shape function is relatively scarce, although the nanoparticle shape greatly impacts their performance; for example, nanorods with a high aspect ratio (AR) achieve greater accumulation, but their penetration is relatively weak. Hence, rather than selecting a suitable AR to balance them, the strategy of a transformable AR (i.e., transformation) is ideal in this case. Nanoparticle transformation can be achieved by either internal stimuli (such as pH and enzymes) or external stimuli (such as light) spatially and temporally with precision, thereby dramatically enhancing the efficiency of drug delivery. Thus, nanoparticle transformation is becoming a promising prospect for improving cancer treatment. In this review, first, the effect of shape on drug delivery is summarized, then, the recently transformable drug delivery systems are reviewed, and finally, the future direction of shape‐transformable nanoparticles in tumor therapy is discussed.
Designing High‐Valence Metal Sites for Electrochemical Water Splitting
Authors: Sun Hainan , Xu Xiaomin , Song Yufei , Zhou Wei , Shao Zongping 
Published: February 2021

AbstractElectrochemical water splitting is a critical energy conversion process for producing clean and sustainable hydrogen; this process relies on low‐cost, highly active, and durable oxygen evolution reaction/hydrogen evolution reaction electrocatalysts. Metal cations (including transition metal and noble metal cations), particularly high‐valence metal cations that show high catalytic activity and can serve as the main active sites in electrochemical processes, have received special attention for developing advanced electrocatalysts. In this review, heterogenous electrocatalyst design strategies based on high‐valence metal sites are presented, and associated materials designed for water splitting are summarized. In the discussion, emphasis is given to high‐valence metal sites combined with the modulation of the phase/electronic/defect structure and strategies of performance improvement. Specifically, the importance of using advanced in situ and operando techniques to track the real high‐valence metal‐based active sites during the electrochemical process is highlighted. Remaining challenges and future research directions are also proposed. It is expected that this comprehensive discussion of electrocatalysts containing high‐valence metal sites can be instructive to further explore advanced electrocatalysts for water splitting and other energy‐related reactions.
Recent Progress in 2D‐Nanomaterial‐Based Triboelectric Nanogenerators
Authors: Liu Yaqian , Ping Jianfeng , Ying Yibin 
Published: February 2021

AbstractThe integration of triboelectric nanogenerators (TENGs) and 2D nanomaterials brings about 2D‐nanomaterial‐based TENGs (2D‐TENGs) that promote the rapid development of self‐powered sensing systems and wearable electronics. Extraordinary physical, electronic, chemical, and optical properties of 2D nanomaterials endow 2D‐TENGs with improved output performance. This review presents the state of the art of 2D‐TENGs with respect to basic classifications, enhancement mechanisms, special advantages, output performances, and applications in energy harvesting and self‐powered sensing. Furthermore, several challenges that can impede applications of 2D‐TENGs are discussed.
Biodegradable Hydrophobic Injectable Polymers for Drug Delivery and Regenerative Medicine
Authors: Arun Yuvaraj , Ghosh Radhakanta , Domb Abraham J. 
Published: February 2021

AbstractBiodegradable, hydrophobic, and injectable liquid polymers are capable of achieving the minimally invasive, sustained, and local release of drugs. These hydrophobic injectable polymers also have potential in the area of regenerative medicine where the biomaterial should be stable for a certain period and then degrade to allow the growth of cells/tissues. This review presents exclusive coverage of biocompatible hydrophobic injectable pasty or liquid polymers that can be injected without the use of any solvent for drug delivery, tissue augmentation, and regenerative medicine application. The synthesis methodologies of several major types of hydrophobic pasty polymers used in the biomedical fields and their properties with the foremost criteria to serve as injectable biomaterial for localized drug delivery and regenerative medicine is described. The hydrophobic biodegradable injectable polymers discussed are aliphatic polyesters, polycarbonates and polyanhydrides, prepared from: lactic acid, glycolic acid, caprolactone, aliphatic diols and diacids, hydroxy fatty acids, and triglycerides such as castor oil.
Passivation Properties and Formation Mechanism of Amorphous Halide Perovskite Thin Films
Authors: Rigter Susan A. , Quinn Xueying L. , Kumar Rishi E. , Fenning David P. , Massonnet Philippe , Ellis Shane R. , Heeren Ron M. A. , Svane Katrine L. , Walsh Aron , Garnett Erik C. 
Published: February 2021

AbstractLead halide perovskites are among the most exciting classes of optoelectronic materials due to their unique ability to form high‐quality crystals with tunable bandgaps in the visible and near‐infrared using simple solution precipitation reactions. This facile crystallization is driven by their ionic nature; just as with other salts, it is challenging to form amorphous halide perovskites, particularly in thin‐film form where they can most easily be studied. Here, rapid desolvation promoted by the addition of acetate precursors is shown as a general method for making amorphous lead halide perovskite films with a wide variety of compositions, including those using common organic cations (methylammonium and formamidinium) and anions (bromide and iodide). By controlling the amount of acetate, it is possible to tune from fully crystalline to fully amorphous films, with an interesting intermediate state consisting of crystalline islands embedded in an amorphous matrix. The amorphous lead halide perovskite has a large and tunable optical bandgap. It improves the photoluminescence quantum yield and lifetime of incorporated crystalline perovskite, opening up the intriguing possibility of using amorphous perovskite as a passivating contact, as is currently done in record efficiency silicon solar cells.
Statistical Piezotronic Effect in Nanocrystal Bulk by Anisotropic Geometry Control
Authors: Liu Shuhai , Han Ming , Feng Xiaolong , Yu Qiuhong , Gu Long , Wang Longfei , Qin Yong , Wang Zhong Lin 
Published: February 2021

AbstractUtilizing inner‐crystal piezoelectric polarization charges to control carrier transport across a metal‐semiconductor or semiconductor–semiconductor interface, piezotronic effect has great potential applications in smart micro/nano‐electromechanical system (MEMS/NEMS), human‐machine interfacing, and nanorobotics. However, current research on piezotronics has mainly focused on systems with only one or rather limited interfaces. Here, the statistical piezotronic effect is reported in ZnO bulk composited of nanoplatelets, of which the strain/stress‐induced piezo‐potential at the crystals’ interfaces can effectively gate the electrical transport of ZnO bulk. It is a statistical phenomenon of piezotronic modification of large numbers of interfaces, and the crystal orientation of inner ZnO nanoplatelets strongly influence the transport property of ZnO bulk. With optimum preferred orientation of ZnO nanoplatelets, the bulk exhibits an increased conductivity with decreasing stress at a high pressure range of 200–400 MPa, which has not been observed previously in bulk. A maximum sensitivity of 1.149 µS m−1 MPa−1 and a corresponding gauge factor of 467–589 have been achieved. As a statistical phenomenon of many piezotronic interfaces modulation, the proposed statistical piezotronic effect extends the connotation of piezotronics and promotes its practical applications in intelligent sensing.
Rubidium Fluoride Modified SnO2 for Planar n‐i‐p Perovskite Solar Cells
Authors: Zhuang Jing , Mao Peng , Luan Yigang , Chen Ningli , Cao Xiaofei , Niu Guosheng , Jia Feifei , Wang Fuyi , Cao Shaokui , Wang Jizheng 
Published: February 2021

AbstractRegulating the electron transport layer (ETL) has been an effective way to promote the power conversion efficiency (PCE) of perovskite solar cells (PSCs) as well as suppress their hysteresis. Herein, the SnO2 ETL using a cost‐effective modification material rubidium fluoride (RbF) is modified in two methods: 1) adding RbF into SnO2 colloidal dispersion, F and Sn have a strong interaction, confirmed via X‐ray photoelectron spectra and density functional theory results, contributing to the improved electron mobility of SnO2; 2) depositing RbF at the SnO2/perovskite interface, Rb+ cations actively escape into the interstitial sites of the perovskite lattice to inhibit ions migration and reduce non‐radiative recombination, which dedicates to the improved open‐circuit voltage (Voc) for the PSCs with suppressed hysteresis. In addition, double‐sided passivated PSCs, RbF on the SnO2 surface, and p‐methoxyphenethylammonium iodide on the perovskite surface, produces an outstanding PCE of 23.38% with a Voc of 1.213 V, corresponding to an extremely small Voc deficit of 0.347 V.
Intracellular Mutual Promotion of Redox Homeostasis Regulation and Iron Metabolism Disruption for Enduring Chemodynamic Therapy
Authors: Liu Yang , Zhai Shaojie , Jiang Xingwu , Liu Yanyan , Wang Kun , Wang Chaochao , Zhang Meng , Liu Xuanyong , Bu Wenbo 
Published: February 2021

AbstractIntracellular redox homeostasis and the iron metabolism system in tumor cells are closely associated with the limited efficacy of chemodynamic therapy (CDT). Despite extensive attempts, maintaining high levels of intracellular catalysts (free iron) and reactants (H2O2) while decreasing the content of reactive oxygen species (ROS) scavengers (especially glutathione (GSH)) for enduring CDT still remains great challenges. Herein, SS bond‐rich dendritic mesoporous organic silica nanoparticles (DMON) are utilized as GSH‐depleting agents. After co‐loading Fe0 and a catalase inhibitor (3‐amino‐1,2,4‐triazole (AT)), a novel biodegradable nanocarrier is constructed as DMON@Fe0/AT. In the mildly acidic tumor microenvironment, on‐demand ferrous ions and AT are intelligently released. AT suppresses the activity of catalase for H2O2 hoarding, and the exposed DMON weakens ROS scavenging systems by persistently depleting intracellular GSH. The highly efficient •OH production by DMON@Fe0/AT can effectively attack mitochondria and downregulate the expression of ferroportin 1, which can disrupt the cellular iron metabolism system, leading to the desired retention of iron in the cytoplasm. More importantly, DMON@Fe0/AT exhibits a much more efficient CDT killing effect on 4T1 tumor cells than plain Fe0 nanoparticles, benefiting from their synergistic redox regulation and iron metabolism disruption. Overall, the as‐prepared intelligent, degradable DMON@Fe0/AT provides an innovative strategy for enduring CDT.
Highly Efficient Room‐Temperature Phosphorescence Based on Single‐Benzene Structure Molecules and Photoactivated Luminescence with Afterglow
Authors: Ma Liangwei , Sun Siyu , Ding Bingbing , Ma Xiang , Tian He 
Published: February 2021

AbstractRecently, a remarkable advance has been made for metal‐free room‐temperature phosphorescence (RTP) crystals with high phosphorescence quantum yield. However, amorphous, especially heavy‐atom‐free, RTP materials still suffer from low quantum yield due to the transition‐forbidden character of phosphorescence and the relatively poor suppression of nonradiative transition in amorphous materials. In this study, a series of single‐benzene structure‐based high intersystem crossing yield phosphor is obtained. After embedding into polyvinyl alcohol matrix, all these phosphor exhibits efficient phosphorescence emission (ФP, up to 44.0%). Besides, photo‐switchable phosphorescence emission can be obtained by doping these molecules into a polymethyl methacrylate (PMMA) matrix. The phosphorescence can be gradually switched on by consuming the residual oxygen in the PMMA matrix under continuous UV light irradiation. Furthermore, the phosphorescence will be spontaneously switched off under ambient conditions. Taking advantage of the photoactivation character, this material has potential in information storage and anti‐counterfeiting.
Molecular Engineering of Mesogenic Constituents Within Liquid Crystalline Elastomers to Sharpen Thermotropic Actuation
Authors: McCracken Joselle M. , Donovan Brian R. , Lynch Kelsey M. , White Timothy J. 
Published: February 2021

AbstractLiquid crystalline elastomers (LCE) are stimuli‐responsive materials with a distinguished mechanical response. LCE have been subject to numerous recent functional examinations in robotics, health sciences, and optics. The liquid crystallinity of the elastomeric polymer networks of LCE are largely derived from liquid crystalline monomer precursors. Recent reports have utilized commercially available liquid crystalline diacrylate monomers in chain extension reactions to prepare LCE. These reactions have been largely based on monomeric precursors originally to enhance the and thermal stability of optical films. Here, it is demonstrated that preparing LCE via a liquid crystalline diacrylate with reduced mesogen–mesogen interaction enhances and sharpens the thermotropic actuation of these materials. Robust composition‐response correlations are demonstrated in LCE prepared by three common synthetic methods. The enhanced thermotropic response of LCE prepared from this precursor increases the thermomechanical efficiency by sixfold. Accordingly, this work addresses important limitations in utilizing the thermal response of LCE in robotics, health care, and consumer goods.
Engineering the MSC Secretome: A Hydrogel Focused Approach
Authors: Wechsler Marissa E. , Rao Varsha V. , Borelli Alexandra N. , Anseth Kristi S. 
Published: February 2021

AbstractThe therapeutic benefits of exogenously delivered mesenchymal stromal/stem cells (MSCs) have been largely attributed to their secretory properties. However, clinical translation of MSC‐based therapies is hindered due to loss of MSC regenerative properties during large‐scale expansion and low survival/retention post‐delivery. These limitations might be overcome by designing hydrogel culture platforms to modulate the MSC microenvironment. Hydrogel systems could be engineered to i) promote MSC proliferation and maintain regenerative properties (i.e., stemness and secretion) during ex vivo expansion, ii) improve MSC survival, retention, and engraftment in vivo, and/or iii) direct the MSC secretory profile using tailored biochemical and biophysical cues. Herein, it is reviewed how hydrogel material properties (i.e., matrix modulus, viscoelasticity, dimensionality, cell adhesion, and porosity) influence MSC secretion, mediated through cell–matrix and cell–cell interactions. In addition, it is highlighted how biochemical cues (i.e., small molecules, peptides, and proteins) can improve and direct the MSC secretory profile. Last, the authors’ perspective is provided on future work toward the understanding of how microenvironmental cues influence the MSC secretome, and designing the next generation of biomaterials, with optimized biophysical and biochemical cues, to direct the MSC secretory profile for improved clinical translation outcomes.
Molecular Imaging of Infarcted Heart by Biofunctionalized Gold Nanoshells
Authors: Muñoz‐Ortiz Tamara , Hu Jie , Ortgies Dirk H. , Shrikhande Shreya , Zamora‐Perez Paula , Granado Miriam , González‐Hedström Daniel , de la Fuente‐Fernández María , García‐Villalón Ángel Luis , Andrés‐Delgado Laura , Martín Rodríguez Emma , Aguilar Río , Alfonso Fernando , García Solé José , Rivera Gil Pilar , Jaque Daniel , Rivero Fernando 
Published: February 2021

AbstractThe unique combination of physical and optical properties of silica (core)/gold (shell) nanoparticles (gold nanoshells) makes them especially suitable for biomedicine. Gold nanoshells are used from high‐resolution in vivo imaging to in vivo photothermal tumor treatment. Furthermore, their large scattering cross‐section in the second biological window (1000–1700 nm) makes them also especially adequate for molecular optical coherence tomography (OCT). In this work, it is demonstrated that, after suitable functionalization, gold nanoshells in combination with clinical OCT systems are capable of imaging damage in the myocardium following an infarct. Since both inflammation and apoptosis are two of the main mechanisms underlying myocardial damage after ischemia, such damage imaging is achieved by endowing gold nanoshells with selective affinity for the inflammatory marker intercellular adhesion molecule 1 (ICAM‐1), and the apoptotic marker phosphatidylserine. The results here presented constitute a first step toward a fast, safe, and accurate diagnosis of damaged tissue within infarcted hearts at the molecular level by means of the highly sensitive OCT interferometric technique.
Pathways of Developing High‐Energy‐Density Flexible Lithium Batteries
Authors: Chang Jian , Huang Qiyao , Gao Yuan , Zheng Zijian 
Published: February 2021

AbstractFlexible lithium‐based batteries (FLBs) enable the seamless implementation of power supply to flexible and wearable electronics. They not only enhance the energy capacity by fully utilizing the available space but also revolutionize the form factors of future device design. To date, how to simultaneously acquire high energy density and excellent mechanical flexibility is the major challenge of FLBs. Here, a critical discussion for guiding the future development of FLBs toward high energy density and high flexibility is presented. First, the industrial criteria of FLBs for several desirable applications of flexible and wearable electronics are summarized. Then, strategies to achieve flexibility of FLBs are discussed, with highlights of representative examples. The performance of FLBs is benchmarked with a flexible battery plot. New materials and cell design principles are analyzed to realize high‐energy‐density and high‐flexibility FLBs. Other important aspects of FLBs including materials to improve the cycling stability and safety are also discussed.
Recent Advances in Inorganic Chiral Nanomaterials
Authors: Liu Junjun , Yang Lin , Qin Ping , Zhang Shiqing , Yung Ken Kin Lam , Huang Zhifeng 
Published: February 2021

AbstractInorganic nanoparticles offer a multifunctional platform for biomedical applications in drug delivery, biosensing, bioimaging, disease diagnosis, screening, and therapies. Homochirality prevalently exists in biological systems composed of asymmetric biochemical activities and processes, so biomedical applications essentially favor the usage of inorganic chiral nanomaterials, which have been widely studied in the past two decades. Here, the latest investigations are summarized including the characterization of 3D stereochirality, the bionic fabrication of hierarchical chirality, extension of the compositional space to poly‐elements, studying optical activities with the (sub‐)single‐particle resolution, and the experimental demonstration in biomedical applications. These advanced studies pave the way toward fully understanding the two important chiral effects (i.e., the chiroptical and enantioselective effects), and prospectively promote the flexible design and fabrication of inorganic chiral nanoparticles with engineerable functionalities to solve diverse practical problems closely associated with environment and public health.
Quantitative Prediction of the Electro‐Mechanical Response in Organic Crystals
Authors: Landi Alessandro , Peluso Andrea , Troisi Alessandro 
Published: February 2021

AbstractOrganic semiconductors’ inherent flexibility makes them appealing for advanced applications such as wearable electronics, e‐skins, or pressure sensors, and can even be used to enhance their intrinsic electronic properties. Unfortunately, these applications for organic materials are currently hindered by the lack of a quantitative understanding of the interplay between their electrical and mechanical properties. In this work, this gap is filled by presenting an accurate methodology able to predict quantitatively the effects of external deformation on the charge transport properties of any organic semiconductors. Three prototypical materials are investigated, showing that the experimental variation of charge carrier mobility with strain is fully reproduced, even in a wide range of deformations applied along different crystal axes. The results indicate that the intrinsic electro‐mechanical response of the materials varies by orders of magnitude within the class of organic semiconductors, a difference rationalized observing that the mobility trend is primarily influenced by the transfer integrals’ variation, rather than by a modification of the crystal phonons. In light of its robustness, accuracy, and low computational cost, this protocol represents an ideal tool to quantify the electro‐mechanical response in new organic compounds, thus establishing a reliable route for a full exploitation of strain engineering in advanced technologies.
Biocatalytic Yarn for Peroxide Decomposition with Controlled Liquid Transport
Authors: Yuan Yue , Zhang Yuxuan , Bilheux Hassina , Salmon Sonja 
Published: February 2021

AbstractA robust biocatalytic yarn with controllable liquid transport properties is created by coating thin layers of chitosan containing catalase onto a cellulosic yarn. The resulting material integrates enzyme catalytic functionality with protective coating properties of chitosan and structural functionality of the textile. Mild immobilization conditions and good affinity between the two polysaccharides minimize enzyme inactivation during the preparation steps and prevent enzyme from leaching during peroxide decomposition testing and washing, providing a novel and versatile enzyme immobilization strategy. The catalytic efficiency of enzymes in a reaction containing solid, liquid, and gas phases is facilitated when dissolved enzyme substrate is transported by liquid flowing through the coated textile structure. The flow‐through configuration decomposes at least two times more peroxide in a twenty‐times smaller reaction zone volume compared to a stirred tank configuration. Liquid transport through the yarn and liquid spatial distribution within the yarn are investigated by in situ neutron radiography and neutron computed tomography, revealing a constrained wicking mechanism that benefits biocatalytic yarn performance. This new class of sustainable and flexible biocatalytic textile matrices has beneficial multifunctional properties, not previously described, that are applicable for numerous small‐ and large‐scale applications including controlled flow reactors and reactive filtration.