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101.
Dandan Bu Yuying Wang Na Wu Wei Feng Donghui Wei Zhanxian Li Mingming Yu 《中国化学快报》2021,32(5):1799-1802
Based on 4-bromo-1,8-naphthalic anhydride, one novel ratiometric fluorescence H2S-probe (IDNA) was designed and synthesized. Further studies indicate that IDNA can sensitively recognize H2S (detection limit of 7 μmol/L) with good selectivity and anti-interference ability. In addition, IDNA has satisfactory photostability in HeLa cells, ability of mitochondrial co-localization, and can be utilized in fluorescence imaging of H2S. 相似文献
102.
This study was to describe the synthesis of complexes of gadolinium diethylenetriaminepentaacetic acid conjugates of low-molecular-weight chitosan oligosaccharide Gd-DTPA-CSn (n = 6, 8, 11) as a new class of contrast agent as well as its magnetic property in a pilot magnetic resonance imaging. The efficacy of the contrast agent was assessed by measuring the longitudinal relaxivity (r1), FLASH imaging in phantoms in vitro and signal intensity in vivo of the rat abdominal axial imaging. The r1 of Gd-DTPA-CS11 was up to 11.65 mM− 1·s− 1, which was 3 times higher than that of the analogous MRI contrast agent Gd-DTPA in commercial use. In vivo MR images of rat obtained with Gd-DTPA-CS11 showed strong signal enhancement in liver and the vessels of the liver parenchyma during the extended period of time. The present study suggests that the new synthesized gadolinium complexes can be used as a new class of practical liver-specific MRI contrast agent because of its superior performance compared with Gd-DTPA. 相似文献
103.
104.
Yuying Qu Yingchun Li Xiaoli Tan Weixiang Zhai Dr. Guifang Han Dr. Jingli Hou Prof. Guoquan Liu Prof. Yuguang Song Prof. Yangping Liu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(33):7888-7895
Tetrathiatriarylmethyl (TAM, trityl) radicals have found wide applications as spin probes/labels for EPR spectroscopy and imaging, and as polarizing agents for dynamic nuclear polarization. The high hydrophilicity of TAM radicals is essential for their biomedical applications. However, the synthesis of hydrophilic TAM radicals (e.g., OX063) is extremely challenging and has only been reported in the patent literature, to date. Herein, an efficient synthesis of a highly water-soluble TAM radical bis(8-carboxyl-2,2,6,6-tetramethylbenzo[1,2-d:4,5-d′]bis([1,3]dithiol-4-yl)-mono-(8-carboxyl-2,2,6,6-tetrakis(2-hydroxyethyl)benzo[1,2-d:4,5-d′]bis([1,3]dithiol-4-yl)methyl (TFO), which contains four additional hydroxylethyl groups, relative to the Finland trityl radical CT-03, is reported. Similar to OX063, TFO exhibits excellent properties, including high water solubility in phosphate buffer, low log P, low pKa, long relaxation times, and negligible binding with bovine serum albumin. On the other hand, TFO has a sharper EPR line and higher O2 sensitivity than those of OX063. Therefore, in combination with its facile synthesis, TFO should find wide applications in magnetic resonance related fields and this synthetic approach would shed new light on the synthesis of other hydrophilic TAM radicals. 相似文献
105.
Thibaut Van Acker Stijn J.M. Van Malderen Marjolein Van Heerden James Eric McDuffie Filip Cuyckens Frank Vanhaecke 《Analytica chimica acta》2016
Two-dimensional elemental mapping (bioimaging) via laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) was performed on 5 μm thick formalin-fixed, paraffin-embedded kidney tissue sections from Cynomolgus monkeys administered with increasing pharmacological doses of cisplatin. Laterally resolved pixels of 1 μm were achieved, enabling elemental analysis on a (sub-)cellular level. Zones of high Pt response were observed in the renal cortex, where proximal tubules are present, the epithelium of which is responsible for partial reabsorption of cisplatin. Histopathological evaluation, of hematoxylin and eosin-stained serial sections, adjacent to the sections probed via LA-ICP-MS, revealed minimal to mild cisplatin-related lesions (<100 μm) in the renal cortex. Necrotic proximal tubules with sloughed epithelial cells in their lumen could be linked directly to the areas with the highest accumulation of cisplatin, indicating a direct link between cellular concentration and toxicity, thereby providing more insight into the mechanisms through which renal damage occurs. 相似文献
106.
Jatinder Kaur Atul Bhardwaj Frank Wuest 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(10):3326-3337
Live-cell imaging with fluorescent probes is an essential tool in chemical biology to visualize the dynamics of biological processes in real-time. Intracellular disease biomarker imaging remains a formidable challenge due to the intrinsic limitations of conventional fluorescent probes and the complex nature of cells. This work reports the in cellulo assembly of a fluorescent probe to image cyclooxygenase-2 (COX-2). We developed celecoxib-azide derivative 14 , possessing favorable biophysical properties and excellent COX-2 selectivity profile. In cellulo strain-promoted fluorogenic click chemistry of COX-2-engaged compound 14 with non/weakly-fluorescent compounds 11 and 17 formed fluorescent probes 15 and 18 for the detection of COX-2 in living cells. Competitive binding studies, biophysical, and comprehensive computational analyses were used to describe protein-ligand interactions. The reported new chemical toolbox enables precise visualization and tracking of COX-2 in live cells with superior sensitivity in the visible range. 相似文献
107.
Near‐infrared emissive (NIR) porphyrin‐implanted carbon nanodots (PCNDs or MPCNDs) are prepared by selectively carbonization of free base or metal complexes [M = Zn(II) or Mn(III)] of tetra‐(meso‐aminophenyl)porphyrin in the presence of citric acid. The as‐prepared nanodots exhibit spontaneously NIR emission, small size, good aqueous dispersibility, and favorable biocompatibility characteristic of both porphyrins and pristine carbon nanodots. The subcellular localization experiment of nanodots indicates a lysosome‐targeting feature. And the in vitro photodynamic therapy (PDT) results on HeLa cells indicate the nanodots alone have no adverse effect on tumor cells, but display remarkable photodynamic efficacy upon irradiation. Moreover, MnPCNDs containing paramagnetic Mn(III) ions, which possesses good biocompatibility, NIR luminescence, and magnetic resonance imaging and efficient singlet oxygen production, are further studied in magnetic resonance imaging‐guided photodynamic therapy in vivo. 相似文献
108.
Andrew J. Heidenreich Judit E. Puskas Michel Schappacher Emmanuel Ibarboure Alain Deffieux 《Journal of polymer science. Part A, Polymer chemistry》2012,50(6):1238-1247
This article presents the utilization of “molecular amplification” to visualize the molecular architecture of “arborescent” (tree‐like) polystyrenes (arbPSs) using atomic force microscopy (AFM). arbPSs with Mn > 80,000 g/mol were synthesized via initiator‐monomer‐type (inimer) RAFT polymerization of styrene mediated by 4‐vinylbenzyl dithiobenzoate in bulk. These arbPS were then used as macrochain transfer agents for polymerization of vinylbenzyl chloride (VBCl) to give arborescent poly(styrene‐block‐vinylbenzyl chloride) (arbPS‐b‐VBCl). Poly(styryl) diphenylethyl lithium (Mn = 11,000 g/mol) was then grafted onto the VBCl units of the arbPS‐b‐VBCl. The Mn of the amplified arbPSs increased over >10 million g/mol, exceeding the exclusion limit of our size exclusion chromatography equipment. AFM confirmed the proposed branches on branches architecture in the samples, together with lesser branched species. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012 相似文献
109.
New insights into water‐soluble and water‐coordinated copper 15‐metallacrown‐5 gadolinium complexes designed for high‐field magnetic resonance imaging applications 下载免费PDF全文
Marina A. Katkova Galina S. Zabrodina Evgeny V. Baranov Maria S. Muravyeva Evgeny A. Kluev Andrey S. Shavyrin Grigory Yu Zhigulin Sergey Yu Ketkov 《应用有机金属化学》2018,32(7)
The development of contrast agents specifically designed for high‐field magnetic resonance imaging (MRI) is required because the relaxation efficiency of classic Gd(III) contrast agents significantly decreases with increasing magnetic field strengths. With an idea of exploring the unique structure of lanthanide (Ln) 15‐MC‐5 metallacrowns, we developed a series of water‐soluble Gd(III) aqua‐complexes, bearing aminohydroxamate (glycine, α‐alanine, α‐phenylalanine and α‐tyrosine) ligands, with increasing number of water molecules directly coordinated to the Gd(III) ion: Gd(H2O)4[15‐MCCu(II)Glyha‐5](Cl)3 ( 1 (Gd)), Gd(H2O)4[15‐MCCu(II)Alaha‐5](Cl)3 ( 2 (Gd)), Gd(H2O)3[15‐MCCu(II)Phalaha‐5](Cl)3 ( 3 (Gd)) and Gd(H2O)3[15‐MCCu(II)Tyrha‐5](Cl)3 ( 4 (Gd)). In these systems, the Ln(III) central ion is coordinated by five oxygen donor atoms of the ligands and three or four inner‐sphere water molecules. The X‐ray crystal structure of metallacrown Ln(H2O)3,4[15‐MCCu(II)Rha‐5]3+ agrees with density functional theory predictions. The calculations demonstrate that the exchange of coordinated water molecules can proceed easily, resulting in increased relaxivity parameters. The longitudinal relaxivities (r1) of 1 (Gd)– 4 (Gd) in water at ultrahigh magnetic field of 9.4 T were determined to be 11.5, 14.8, 13.9 and 12.2 mM?1 s?1, respectively. The ability to increase the number of Ln(III) inner‐sphere water molecules up to four, the planar metallacrown structure and the rich hydration shell due to strong hydrogen bonds between the [15‐MC‐5] moiety and bulk water molecules provide new opportunities for potential MRI applications. 相似文献
110.