摘要：Scaffolds play a crucial role in tissue engineering. Biodegradable polymers with great processing flexibility are the predominant scaffolding materials. Synthetic biodegradable polymers with well-defined structure and without immunological concerns associated with naturally derived polymers are widely used in tissue engineering. The synthetic biodegradable polymers that are widely used in tissue engineering, including polyesters, polyanhydrides, polyphosphazenes, polyurethane, and poly(glycerol sebacate) are summarized in this article. New developments in conducting polymers, photoresponsive polymers, amino-acid-based polymers, enzymatically degradable polymers, and peptide-activated polymers are also discussed. In addition to chemical functionalization, the scaffold designs that mimic the nano and micro features of the extracellular matrix(ECM) are presented as well, and composite and nanocomposite scaffolds are also reviewed.

摘要：New multilayer coatings were produced by incorporating alternating soft and hard DLC layers enabled by varying the bias voltage during deposition process while maintaining a constant hard-to-soft layer thickness *** coatings were deposited onto a Cr/Cr Cxgraded layer by closed field unbalanced magnetron sputtering(CFUBMS).The cross-sectional analysis of the coatings showed that the multilayer coatings possess sharp interfaces between the soft and hard layers with the hard to soft layer thickness ratio(1:1.33)constant in all the *** analysis uncovered the increasing sp^(3)character of the DLC coatings as a result of decreasing ID/IGratio and increasing full width at half maximum(FWHM)values of the G band peak induced supposedly by an increase in bias voltage during hard layer *** tests showed an increase in hardness of the DLC coatings which can be correlated with the increase in the sp^(3)content of the coatings as well as decreasing sp^(2)-C cluster size,as calculated from the ID/***,the coatings exhibited excellent plastic deformation resistance and adhesion strength upon microindentation and scratch testing,*** further investigations are required to assess coating durability,the multilayer design could offer the DLC coatings with a rare opportunity to combine the high hardness with damage resistance with a constant bilayer thickness and without the need to introduce complex multilayer system.

摘要：Regulation of osteogenic differentiation of bone mesenchymal stromal cells （BMSCs） plays a critical role in bone regeneration. As small non-coding RNAs, microRNAs （miRNAs） play an important role in stem cell differentiation through regulating target-mRNA expression. Unfortunately, highly efficient and safe delivery of miRNAs to BMSCs to regulate their osteogenic differentiation remains challenging. Conventional inorganic nanocrystals have shown increased toxicity owing to their larger size precluding renal clearance. Here, we developed novel, surface-engineered, ultra-small gold nanoparticles （USAuNPs, 〈10 nm） for use as highly efficient miR-5106-delivery systems to enable regulation of BMSC differentiation. We exploited the effects of AuNPs coated layer-by-layer with polyethylenimine （PEI） and liposomes （Lipo） to enhance miR-5106-delivery activity and subsequent BMSC differentiation capacity. The PEI- and Lipo-coated AuNPs （Au@PEI@Lipo） showed negligible cytotoxicity, good miRNA-5106-binding affinity, highly efficient delivery of miRNAs to BMSCs, and long-term miRNA expression （21 days）. Additionally, compared with commercial Lipofectamine 3000 and 25 kD PEI, the optimized Au@PEI@Lipo-miR-5106 nanocomplexes significantly enhanced BMSC differentiation into osteoblast-like cells through activation of the Sox9 transcription factor. Our findings reveal a promising strategy for the rational design of ultra-small inorganic nanoparticles as highly efficient miRNA-delivery platforms for tissue regeneration and disease therapy.

摘要：J-aggregates of cyanine have shown great merits in tumor photothermal therapy(PTT)due to their distinct redshift absorption as well as superior photothermal conversion efficiency(PCE).However,due to the complexity of intermolecular interactions,especially the impact of steric hindrance on aggregation,exploring effective strategies to regulate the aggregation modes of organic materials remains ***,steric hindrance-regulated J-aggregation of near-infrared(NIR)cyanine was reported based on Pt-coordinated cyanine self-assembly with unexpected“butterfly effect”.Two Pt-coordinated cyanine dimers CyR-Pt(R=Me and Et)were synthesized and spontaneously self-assembled into aggregates in aqueous ***-Pt aggregates were loose and amorphous *** replacing ethyl with methyl to reduce steric hindrance,a tiny change resulted in the generation of tightly stacked cyanine J-aggregates(thickness less than 3 nm)observed in CyMe-Pt ***,this unexpected“butterfly effect”enabled CyMe-Pt J-aggregates to effectively inhibit reactive oxygen species and greatly improve its ***,CyMe-Pt J-aggregates with NIR-II absorption exhibited outstanding photothermal stability and higher PCE(η=37%)than CyEt-Pt disordered aggregates(η=20%).Evident tumor suppression performance of CyMe-Pt J-aggregates was validated under 980 nm laser irradiation,demonstrating its great potential in tumor PTT.

摘要：The structural complexity of supported metal catalysts,playing significant role in a wide range of chemical technologies,have prevented us from deeply understanding their catalytic mechanisms at atomic level.A fundamental understanding of the nature of active sites and structure–performance relationship of supported metal catalysts from a comprehensive view will open up numerous new opportunities for the development of advanced catalysts to address the global challenges in energy conversion and environmental *** review surveys the effects of multiple factors,including the metal size,shape,support,alloy and ligand modifier,on the coordinated environment of active center and further their influence on the catalytic reactions,aiming to provide guidance for the design of industrialized heterogeneous catalysts with extraordinary ***,the key structure characterization techniques in determining the coordination structure of active metal sites,especially the dynamic coordination structure change under the reaction condition,are well summarized.A brief summary is finally provided together with personal perspectives on the further development in the field of heterogeneous metal catalysts.

摘要：Surface plasmon resonance(SPR)of metals may provide a way to improve light absorption and utilization of semiconductors,achieving better solar light conversion and photocatalysis *** study uses the advantages of SPR in metallic Bi and artificial defects to cooperatively enhance the photocatalytic performance of *** catalysts were prepared by partial reduction of BiOI to form Bi@defective BiOI,which showed highly enhanced visible photocatalytic activity for NOx *** effects of reductant quantity on the photocatalytic performance of Bi@defective BiOI were *** as-prepared photocatalyst(Bi/BiOI-2)using 2 mmol of reductant NaBH4 showed the most efficient visible light photocatalytic *** enhanced activity can be ascribed to the synergistic effects of metallic Bi and oxygen *** electrons from the valence band tend to accumulate at vacancy states;therefore,the increased charge density would cause the adsorbed oxygen to transform more easily into superoxide radicals and,further,into hydroxyl *** radicals are the main active species that oxidize NO into final *** SPR effect of elemental Bi enables the improvement of visible light absorption efficiency and the promotion of charge carrier separation,which are crucial factors in boosting *** adsorption and reaction processes on Bi/BiOI-2 were dynamically monitored by in situ infrared spectroscopy(FT-IR).The Bi/BiOI photocatalysis mechanism co-mediated by elemental Bi and oxygen vacancies was proposed based on the analysis of intermediate products and DFT *** present work could provide new insights into the design of high-performance photocatalysts and understanding of the photocatalysis reaction mechanism for air-purification applications.

摘要：Heterostructured photocatalysts provide an effective way to achieve enhanced photocatalytic performances through efficient charge *** both wide-and narrow-band-gap photocatalysts have been widely investigated,the charge separation and transfer mechanism at the contacting interface of the two has not been fully ***,a novel SrTiO3/BiOI(STB)heterostructured photocatalyst was successfully fabricated by using a facile *** heterostructure in the photocatalyst extends the photoabsorption to the visible light range,and thus,high photocatalytic NO removal performance can be achieved under visible light irradiation.A combination of experimental and theoretical evidences indicated that the photogenerated electrons from the BiOI semiconductor can directly transfer to the SrTiO3 surface through a preformed electron delivery *** electron transfer was expected between the SrTiO3 and BiOI surfaces under light irradiation,and leads to efficient ROS generation and thus a high NO conversion ***,in situ diffused reflectance infrared Fourier transform spectroscopy revealed that STB can better inhibit the accumulation of the toxic intermediate NO2 and catalyze the NO oxidation more *** work presents a new insight into the mechanism of the interfacial charge separation in heterostructures and provides a simple strategy to promote the photocatalytic technology for efficient and safe air purification.

摘要：本文设计合成了两种具有不同连接方式(亚胺键和sp^(2)-C-CN键)的三嗪基共价有机框架(COFs)材料.连接单元的微小变化导致可见光驱动制氢性能的巨大差异.具有sp^(2)碳连接方式的全π共轭二维COFs在450 nm波长处表现出13.48%的外量子效率,优于已报道的COFs光催化剂.而亚胺键的二维COFs几乎没有光活性.借助光电化学研究和量子化学计算进一步研究了二维COFs的催化机理,为太阳能转化高性能有机光催化剂的制备提供了新的见解.

摘要：The rational design and construction of inexpensive and highly active electrocatalysts for hydrogen evolution reaction(HER)is of great importance for water ***,we develop a facile approach for preparation of porous carbon-confined Ru-doped Cu nanoparticles(denoted as Ru-Cu@C)by direct pyrolysis of the Ru-exchanged Cu-BTC metal–organic *** served as the electrocatalyst for HER,strikingly,the obtained Ru-Cu@C catalyst exhibits an ultralow overpotential(only 20 mV at 10 mA cm^(-2))with a small Tafel slope of 37 m V dec^(-1)in alkaline *** excellent performance is comparable or even superior to that of commercial Pt/C *** functional theory(DFT)calculations confirm that introducing Ru atoms into Cu nanocrystals can significantly alter the desorption of H_(2) to achieve a close-to-zero hydrogen adsorption energy and thereby boost the HER *** strategy gives a fresh impetus to explore low-cost and high-performance catalysts for HER in alkaline media.

摘要：Solar-driven vapor generation by localized solar heating of a photothermal material is an environmentally friendly approach for seawater desalination and wastewater *** this work,inspired by the leaf transpiration in nature,we designed a novel bionic leaf to realize highly efficient solar vapor *** leaf-inspired three-dimensional(3D)material structure had a hydrophilic polyvinyl alcohol(PVA)foam layer(equivalence to the mesophyll tissue layer in a leaf)with high porosity and low thermal conductivity,a photothermal polypyrrole(PPy)layer(equivalence to the chlorophyll layer in a leaf)coated on the PVA foam,and a micro/nano-scale porous hydrophobic surface layer(equivalence to the stomal layer in a leaf).The PVA network had microchannels for water transportation and reducing water evaporation enthalpy,the PPy layer absorbed and converted solar energy to heat water locally,and the hydrophobic porous surface layer enhanced the rate of vapor *** asfabricated vapor generator based on the bionic-leaf structure achieved an impressive high evaporation rate of 3.09 kg m^(−2) h^(−1) under one sun irradiation(1 kW m^(−2)).The prototype vapor generator desalinated and purified brine and seawater successfully under natural *** solar vapor generator based on the biomimetic structure provides a potential low-cost and highly efficient water purification technology to help mitigate the global water crisis using sustainable energy.