基于DNA的细胞膜功能化

细胞膜在细胞与外界环境间的物质运输、能量转换和信息传递等过程中起着重要作用,研究和控制细胞膜上的分子的相互作用,对理解和操控细胞的生理功能具有重要意义。脱氧核糖核酸(Deoxyribonucleic acid, DNA)分子具有精确自组装和可编程的特性,是一种研究生物膜分子相互作用的新工具。本综述中,我们概括了DNA分子修饰细胞膜的方法,随后介绍了基于DNA分子的监测、控制细胞膜分子相互作用的工作以及DNA分子介导细胞连接的研究,并分析了上述研究的局限性。最后,我们对基于DNA的细胞膜功能化研究进行总结与展望,以期促进对细胞膜功能的新认识,获得控制细胞功能的新方法。     

Thermodynamic properties of gaseous cerium phosphate studied by Knudsen effusion mass spectrometry

Gaseous CePO₂ has been identified by Knudsen effusion mass spectrometry during vaporization of CeO₂ and magnesium diphosphate from tungsten double, two‐temperature effusion cell. Structure and molecular parameters of gaseous cerium phosphate under study were determined using quantum chemical calculations. On the basis of equilibrium constants measured for gas‐phase reaction, standard formation enthalpy of CePO₂ was determined to be ?508 ± 41 kJ ? mol^?1 at the temperature 298 K.     

骨架非稠合的电子受体在聚合物太阳能电池中的应用

Non-fullerene electron acceptors have attracted enormous attention of the research community owing to their advantages of optoelectronic and chemical tunabilities for promoting high-performance polymer solar cells (PSCs). Among them, fused-ring electron acceptors (FREAs) are the most popular ones with the good structural planarity and rigidity, which successfully boost the power conversion efficiencies (PCEs) of PSCs to over 14%. In considering the cost-control of future scale-up applications, it is also worthwhile to explore novel structures that are easy to synthesize and still maintain the advantages of FREAs. In this work, we design and synthesize a new electron acceptor with an unfused backbone, 5, 5'-((2, 5-bis((2-hexyldecyl)oxy)-1, 4-phenylene)bis(thiophene-2-yl))bis(methanylylidene)) bis(3-oxo-2, 3-dihydro-1H-indene-2, 1-diylidene))dimal-ononitrile (ICTP), which contains two thiophenes and one alkoxy benzene as the core and 2-(3-oxo-2, 3-dihydroinden-1-ylidene) malononitrile (IC) as the terminal groups. The synthetic route to ICTP involves only three steps, with high yields. Density functional theory calculations indicate that the non-covalent interactions, O…H and O…S, help reinforce the space conformation between the central core and the terminals. ICTP shows broad and strong absorption in the long-wavelength range between 500 and 760 nm. The highest occupied molecular orbital and lowest unoccupied molecular orbital levels of ICTP were measured to be -5.56 and -3.84 eV by cyclic voltammetry. The suitable absorption and energy levels make ICTP a good acceptor candidate for medium bandgap polymer donors. The best devices based on PBDB-T:ICTP showed a PCE of 4.43%, with an open circuit voltage (V_OC) of 0.97 V, a short circuit current density (J_SC) of 8.29 mA∙cm^-2, and a fill factor (FF) of 0.55, after adding 1% 1, 8-diiodooctane (DIO) as the solvent additive. Atomic force microscopy revealed that DIO could ameliorate the strong aggregation in the blended film and lead to a smoother film surface. The hole and electron mobilities of the optimized device were measured to be 9.64 and 2.03 × 10^-5 cm²∙V^-1∙s^-1, respectively, by the space-charge-limited current method. The relatively low mobilities might be responsible for the moderate PCE. Further studies can be performed to enlarge the conjugation length by including more aromatic rings. This study provides a simple strategy to design non-fullerene acceptors and a valuable reference for the future development of PSCs.     

Two-Photon Absorption and Cell Imaging of Fluorene-Functionalized Epicocconone Analogues

Epicocconone 1 is a natural chromophore isolated from the fungus Epicoccum nigrum that has shown applications in proteomics and fluorescent microscopy thanks to its unique pro-fluorescence properties. The modification of the skeleton of the natural product by replacing the triene side chain by a fluorenyl scaffold can noticeably increase the fluorophore's absorption coefficient. The synthesis of the analogues of the natural product has been made possible by the use of a palladium-catalyzed carbonylation reaction, allowing the construction of the β-keto-dioxinone key intermediate. Two-photon absorption cross-section measurements of the fluorenyl epicocconone analogues show a structure dependency with values ranging from 60 to 280 GM and live cell imaging show intense staining of intracellular vesicle-like structures around the nucleus.     

Design,Synthesis, and Phenotypic Profiling of Pyrano‐Furo‐Pyridone Pseudo Natural Products

Natural products (NPs) inspire the design and synthesis of novel biologically relevant chemical matter, for instance through biology‐oriented synthesis (BIOS). However, BIOS is limited by the partial coverage of NP‐like chemical space by the guiding NPs. The design and synthesis of “pseudo NPs” overcomes these limitations by combining NP‐inspired strategies with fragment‐based compound design through de novo combination of NP‐derived fragments to unprecedented compound classes not accessible through biosynthesis. We describe the development and biological evaluation of pyrano‐furo‐pyridone (PFP) pseudo NPs, which combine pyridone‐ and dihydropyran NP fragments in three isomeric arrangements. Cheminformatic analysis indicates that the PFPs reside in an area of NP‐like chemical space not covered by existing NPs but rather by drugs and related compounds. Phenotypic profiling in a target‐agnostic “cell painting” assay revealed that PFPs induce formation of reactive oxygen species and are structurally novel inhibitors of mitochondrial complex I.     

Screening potential antagonists of epidermal growth factor receptor from Marsdenia tenacissima via cell membrane chromatography model assisted by HPLC–ESI–IT–TOF–MS

Marsdenia tenacissima, or Tongguanteng in Chinese, is a traditional Chinese herb and has a broad application in clinical practice for its pharmacological effects of treating asthma, pneumonia, tonsillitis, pharyngitis tumors, etc. However, few studies have reported the screening of the active components of this medicine for tumor therapy. In this work, a two‐dimensional analytical system was developed to screen antagonists of epidermal growth factor receptor (EGFR) from M. tenacissima. A fraction was retained on the EGFR cell membrane chromatography (CMC) column, separated and identified as tenacissoside G (TG), tenacissoside H (TH) and tenacissoside I (TI) by two‐dimensional HPLC–IT–TOF–MS. Molecular docking and 3‐(4,5‐dimethyl‐2‐thiazolyl)‐2,5‐diphenyl‐2‐H‐tetrazolium bromide (MTT) assay were carried out to assess the activity of TS (including TG, TH and TI). Molecular docking results showed that the binding mode of TS on EGFR is similar to that of gefitinib. The MTT assay demonstrated that gefitinib and TS (especially TI) could inhibit the growth of EGFR highly expressed cell lines in a dose‐dependent manner in the range of 5–50 μmol/L. In conclusion, the two‐dimensional EGFR/CMC–HPLC–IT–TOF–MS system could be a useful approach in drug discovery from traditional Chinese medicines for searching for potential antitumor candidates.     

Synthesis and properties of mono‐ and di‐fluoro‐substituted 2,3‐didodecylquinoxaline‐based polymers for polymer solar cells

We synthesized two new alternating polymers, namely P(Tt‐FQx) and P(Tt‐DFQx) , incorporating electron rich tri‐thiophene and electron deficient 6‐fluoroquinoxaline or 6,7‐difluoroquinoxaline derivatives. Both polymers P(Tt‐FQx) and P(Tt‐DFQx) exhibited high thermal stabilities and the estimated 5% weight loss temperatures are 425 and 460 °C, respectively. Polymers P(Tt‐FQx) and P(Tt‐DFQx) displayed intense absorption band between 450 and 700 nm with an optical band gap (E_g) of 1.78 and 1.80 eV, respectively. The determined highest occupied/lowest unoccupied molecular orbital's (HOMO/LUMO) of P(Tt‐DFQx) (?5.48 eV/?3.68 eV) are slightly deeper than those of P(Tt‐FQx) ( ?5.32 eV/?3.54 eV). The polymer solar cells fabricated with a device structure of ITO/PEDOT:PSS/ P(Tt‐FQx) or P(Tt‐DFQx) :PC₇₀BM (1:1.5 wt %) + 3 vol % DIO/Al offered a maximum power conversion efficiency (PCE) of 3.65% with an open‐circuit voltage (V_oc) of 0.59 V, a short‐circuit current (J_sc) of 10.65 mA/cm² and fill factor (FF) of 59% for P(Tt‐FQx) ‐based device and a PCE of 4.36% with an V_oc of 0.69 V, a J_sc of 9.92 mA/cm², and FF of 63% for P(Tt‐DFQx) ‐based device. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019 , 57, 545–552     

Synthesis and Characterization of Phenolphthalein‐Containing Sulfonated Poly(arylene ether phosphine oxide)s by Direct Polycondensation for Proton Exchange Membrane

A series of novel phenolphthalein‐containing sulfonated poly(arylene ether phosphine oxide)s (sPAEPP) with various sulfonation degrees were synthesized by direct polycondensation. The structure of sPAEPP was confirmed by ¹H‐NMR, ¹³C‐NMR, and IR spectroscopy. The high‐molecular weight of these polymers was determined by gel permeation chromatography (GPC). The transparent, tough, and flexible membranes could be achieved by solution casting. The macroscopic properties and microstructure of the obtained membranes were investigated in detail. The results showed that these sPAEPP membranes displayed excellent properties in terms of swelling, proton conductivity, and methanol permeability. For example, sPAEPP‐100 membrane exhibited an appropriate water uptake of 33.1%, a swelling ratio of only 11.7% (lower than 20.1% of Nafion 117), a proton conductivity of 0.11 S cm^?1 (similar to that of Nafion 117) at 80 °C, and a methanol permeability of 4.82 × 10^?7 cm² s^?1. Meanwhile, it also presented outstanding oxidative stability. Atomic force microscope (AFM) micrographs showed that the hydrophilic domains of the sPAEPP‐100 membrane formed connected and narrow ionic channels, which contributed to its high proton conductivity and good dimensional stability. As a result, sPAEPP‐100 membrane displays excellent application prospect for fuel cells. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019 , 57, 1097–1104     

借助液体透射电镜原位分析钯纳米棒的可控性氧化刻蚀

借助原位液体透射电镜,我们观察并研究了钯纳米棒溶液环境下的氧化刻蚀的微观行为及机理。通过改变钯纳米棒所处的液体环境,有效地控制了钯纳米棒的氧化刻蚀行为。由于端部具有较高的反应活性,钯纳米棒在氯化铁溶液中的氧化刻蚀会选择沿着轴向进行,具有明显的各向异性。当反应在超薄液层进行时,钯纳米棒的氧化刻蚀会变为准各向同性。这种行为是由于超薄溶液中溶解产物以及氧化物的扩散被抑制,在纳米棒端部选择性发生的氧化刻蚀会受到阻碍。最后,我们发现在钯纳米棒端部选择性沉积金,可以保护纳米棒的端部不受氧化,从而能控制刻蚀沿着钯纳米棒的径向进行。本文的研究结果对贵金属纳米晶的结构参数的精确调控以利于实际应用具有重要的意义。     

Synthesis,cytotoxicity, apoptosis and cell cycle arrest of a monoruthenium(II)-substituted Dawson polyoxotungstate

By 5-h reaction of cis-[Ru^IICl₂(DMSO)₄] (M2) with K₁₀[α₂-P₂W₁₇O₆₁] (M3) in ice-cooled, HCl-acidic aqueous solution, a water-soluble 1:2-type diamagnetic ruthenium(II) complex of formula K₁₈[Ru^II(DMSO)₂(P₂W₁₇O₆₁)₂]·35H₂O (M1) was unexpectedly obtained as an analytically pure, homogeneous tan-colored solid, in which two DMSO ligands are coordinated to the ruthenium(II) atom. The cytotoxic potential of the complex was tested on C33A, DLD-1, and HepG-2 cancer cells and human normal embryonic lung fibroblasts cell MRC-5; the viability of the treated cells was evaluated by MTT assay. The mode of cell death was assessed by morphological study of DNA damage and apoptosis assays. Compound M1 induced cell death in a dose-dependent manner, and the mode of cell death was essentially apoptosis though necrosis was also noticed. Cell cycle analysis by flow cytometry indicated that M1 caused cell cycle arrest and accumulated cells in S phase.