Analytical Methods
·
2015
·Vol. 7
·期 9
·3883-3887
·
IF 1.821
Hao-Ming Lv,Yi Chen,Jian Lei,Chak-Tong Au,Shuang-Feng Yin
Nitroxyl is a highly reactive compound that irreversibly dimerizes and subsequently dehydrates to yield nitrous oxide and water, making its direct detection in cells or in vivo difficult. In this paper, a novel fluorescent probe 1 based on the excited state intramolecular proton transfer (ESIPT) mechanism for the detection of nitroxyl was developed for the first time. It consists of 2-(2′-hydroxyphenyl)-benzothiazole as the fluorophore, linked via an ester moiety to a diphenylphosphinobenzoyl group. The probe exhibited high sensitivity and selectivity toward nitroxyl in the presence of biologically relevant species. Moreover, the potential for biological applications of the probe was confirmed by employing it for fluorescence imaging of nitroxyl in living cells.
研究领域:
生物化学
·
分析化学
·
细胞生物学
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DOI
高影响因子
Analytical Methods
·
2019
·Vol. 11
·期 6
·832-843
·
IF 2.378
Qiujuan Ma,Junhong Xu,Guojiang Mao,Xiaoyu Guo,Beibei Liang,Yu Bai,Chunyan Wang
In this work, we developed a novel fluorescent probe 1 for quantitative detection of nitroxyl (HNO). Probe 1 consisted of a naphthalene backbone and 2-(diphenylphosphino)benzoate which was used as a nitroxyl recognition unit. The probe exhibited an intense fluorescence turn-on response to nitroxyl via aza-ylide formation and its subsequent Staudinger ligation to release compound 2. The probe can be applied to the quantification of nitroxyl with a linear range from 5.0 × 10−8 to 9.0 × 10−6 mol L−1. The detection limit of probe 1 toward nitroxyl was estimated to be 43 nM. Furthermore, probe 1 displayed a much higher selectivity for nitroxyl than other biologically relevant species. Importantly, owing to the high cell permeability and low cytotoxicity of probe 1, it was successfully applied to cell imaging of nitroxyl in living cells. The probe is expected to be a useful chemical tool for investigating the detailed functions and mechanisms of HNO in living systems.
研究领域:
分析化学
·
生物化学
·
医学
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DOI
高影响因子
PROCESS SAFETY AND ENVIRONMENTAL PROTECTION
·
2015
·
IF 2.551
Guibin Lu,Caixing Zhang,Liping Chen,Wanghua Chen,Ting Yang,Yishan Zhou
To study the thermal hazard of β-nitroso-α-naphthol, both dynamic and isothermal tests were performed with a differential scanning calorimeter (DSC). The dynamic tests indicated that the initial decomposition temperature of β-nitroso-α-naphthol ranged from 153 °C to 173 °C. The interrupt-rescanning method verified the autocatalytic characteristic of β-nitroso-α-naphthol decomposition. DSC curves obtained at five constant temperatures confirmed that the decomposition of β-nitroso-α-naphthol was an autocatalytic reaction. Activation energy E was 149 ± 8 kJ mol −1 calculated by Kissinger method. E values calculated by induction period method and isothermal method were in line with that obtained by Friedman method. On the basis of the kinetic analysis, the safety parameter SADT of β-nitroso-α-naphthol in 50 kg standard packaging was 81 °C based on Semenov model and 67 °C based on Frank-Kamenetskii model.
研究领域:
化学动力学
·
热安全分析
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DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2023
·
IF 8.2
Pin Chen,Huan Cheng,Jinhu Tian,Haibo Pan,Shiguo Chen,Xingqian Ye,Jianle Chen
In recent years, the incidence of inflammatory bowel disease has gradually increased. Traditional drugs can reduce inflammation, but cannot be targeting released and often require the coordination with delivery systems. However, a good targeting performance delivery system is still scarce currently. Inflammation can trigger oxidative stress, producing large amounts of oxides such as nitric oxide (NO). Based on this, the present experiment innovatively designed a hydrogel delivery system with NO response that could be inflammation targeting. The hydrogel is composed of sodium alginate modified with glycerol methacrylate, crosslinked with NO response agent by photo-crosslinking method, which have low swelling (37 %) and good mechanical properties with a stable structure even at 55 °C. The results of in vitro digestion also indicated that the hydrogel had a certain tolerance to gastrointestinal digestion. And in the NO environment, it was interestingly found that the structure and mechanical properties of the hydrogels changed significantly. Moreover, hydrogels have good biocompatibility, which ensures their safe use in vivo. In conclusion, this NO-responsive-based delivery system is feasible and provides a new approach for drugs and active factors targeting delivery in the future.
研究领域:
生物材料学
·
药物递送系统
·
炎症研究
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产品关联
DOI
PubMed
高影响因子
Materials Today Communications
·
2020
·
IF 2.678
Lili Wang,Panpan Hao,Xiaomeng Chu,Yujuan Sun,Xuteng Xing,Shaojie Liu,Erjun Tang,Xiaodong Xu
With 2,2,6,6-tetramethylpiperidin-4-yl methacrylate (TMPM) and styrene (St) as monomers, the block copolymer brush of PS-PSt-PTMPM was grafted on micro-sized polystyrene microsphere via the electron transfer regenerated catalyst atom transfer radical polymerization (ARGET ATRP). The piperidine groups of PTMPM block were then oxidized to nitroxide radicals by 3-chlorobenzoic acid and PSt block was sulfonated with sulfuric acid to give the dual-functionalized block copolymer brush of PS-PSH-PTMA containing both nitroxide radicals and sulfonic acid groups. PS-PSH-PTMA was used for the direct esterification of methacrylic acid (MAA) and methoxy poly(ethylene glycol) (MPEG) for synthesis of methoxy poly(ethylene glycol) methyl acrylates (MPEGMA) instead of free acid catalyst of p-toluene sulfonic acid and free inhibitor of 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO), since the immobilized TEMPO units prevented the undesired radical self-polymerisation and the immobilized sulfonic acid residues catalyzed the esterification. The results showed that the esterification rate of MPEGMA with PS-PSH-PTMA as catalyst and inhibitor was over 99% and the reaction rate was twice as high as that with p-toluene sulfonic acid as catalyst and TEMPO as inhibitor. Furthermore, PS-PSH-PTMA could be easily recovered by filtration and the recycling performance was excellent.
研究领域:
高分子化学
·
催化化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry B
·
2024
·
IF 6.1
Ziwei Duan,Jialei Han,Yadong Liu,Xinyu Zhao,Bo Wang,Shuaishuai Cao,Dalin Wu
Magnetic resonance imaging (MRI) has emerged as a pivotal tool in contemporary medical diagnostics, offering non-invasive and high-resolution visualization of internal structures. Contrast agents are essential for enhancing MRI resolution, accurate lesion detection, and early pathology identification. While gadolinium-based contrast agents are widely used in clinical, however, safety concerns have prompted exploration of metal-free alternatives, including fluorine and nitroxide radical-based MRI contrast agents. Fluorine-containing compounds exhibit excellent MRI capabilities, with 19F MRI providing enhanced resolution and quantitative assessment. Nitroxide radicals, such as PROXYL and TEMPO, offer paramagnetic properties for MRI contrast. Despite their versatility, nitroxide radicals suffer from lower relaxivity values (r1) compared to gadolinium. Dual-modal imaging, combining 1H and 19F MRI, has gained prominence for its comprehensive insights into biological processes and disease states. However, existing dual-modal agents predominantly utilize gadolinium-organic ligands without incorporating nitroxide radicals. Here, we introduce a novel dual-modal MRI contrast agent (J-CA) featuring a Janus asymmetric nanostructure synthesized via seeded emulsion polymerization and post-modification. J-CA demonstrates excellent in vitro and in vivo performance in both 19F and 1H MRI, with T2 relaxation time of 5 ms and r1 of 0.31 mM-1·s-1, ensuring dual-modal imaging capability. Moreover, J-CA exhibits superior biocompatibility and organ targeting, making it a promising candidate for precise lesion imaging and disease diagnosis. This work introduces a new avenue for metal-free dual-modal MRI, addressing safety concerns associated with traditional contrast agents.
研究领域:
医学诊断
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磁共振成像 (MRI)
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造影剂
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纳米技术
·
生物医学工程
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF POLYMER RESEARCH
·
2023
·Vol. 30
·期 9
·1-8
·
IF 2.8
Qiao Xiaoguang,Dong Xin,shi Ge,He Yanjie,Pang Xinchang
The postsynthesis polymeric modifications by grafting from the active sites were the primary focus of the structurally tailored and engineered macromolecular (STEM) gels. Therefore, Reversible-deactivation radical polymerization (RDRP) techniques have been employed to more precisely tailor and tune STEM gels. In contrast to atom transfer radical polymerization (ATRP) and reversible addition-fragmentation chain transfer polymerization (RAFT), nitroxide-mediated polymerization (NMP) is known to have the advantages of simple components and pure products. Here we report the preparation of polydimethylsiloxane (PDMS) composite gel networks through oxygen tolerance NMP process, with tert-Butyl acrylate (tBA) and fluorinated monomer 2-(Perfluorooctyl)ethyl methacrylate (FMA) as functional comonomers. Compared with conventional radical polymerization (FRP) method, composite gels prepared through NMP method showed higher swelling rate and elongation at break, which proved that the network structure formed by NMP was more uniform. In addition to better thermal stability and toughness, the dormant polymer chain could be reactivated and lead to the “living” post-modification of PDMS gel matrix.
研究领域:
材料科学
·
高分子化学
·
材料工程
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产品关联
DOI
高影响因子
Applied Materials Today
·
2019
·
IF 8.013
Ozioma Udochukwu Akakuru,M. Zubair Iqbal,Chuang Liu,Jie Xing,Zhenni Wei,Zhenqi Jiang,Qianlan Fang,Bo Yuan,Elvis Ikechukwu Nosike,Jianbi Xia,Yinhua Jin,Jianjun Zheng,Aiguo Wu
Magnetic resonance imaging (MRI) signal intensities in tissues are usually enhanced by the injection of metal-based contrast agents (CAs) in patients. Some of these metal compounds have been linked to incurable nephrogenic systemic fibrosis and other neurological disorders, leading to their discontinuation. Herein, we report the design, synthesis, and characterization of a self-assembled metal-free CA which is based on an organic nitroxide radical (4-carboxy-TEMPO) compartmentalized in the biocompatible, biodegradable natural polymer, chitosan (CS), alongside folate targeting for in vivo tumor MRI. This extension conceivably heralds a new application for CS-TEMPO, which hitherto was used in macro-sizes as initiators for grafting CS to various polymers. Significantly, the folic acid (FA)-modified metal-free CA (CS-TEMPO-FA; average size ∼113 nm) is substantially benign, with no evidence of acute toxicity; it exhibits desirable pharmacokinetic profile, enhanced stability in highly reducing environments, high nitroxide loading (molecular relaxivity ∼18.56 mM −1 s −1 ), and effective tumor targeting. This latter characteristic ameliorates the non-specific uptake of CAs by normal cells. CS-TEMPO-FA nanoparticles demonstrate commensurate contrast enhancement of the tumor region up to 1 h post-injection when injected into 4T1 tumor-bearing mice, a contrast enhancement capability hitherto unattained by TEMPO-based CAs. This work points to CS-TEMPO-FA as a potential alternative to metal-based CAs as well as an active folate-targeted metal-free CA for long-term longitudinal tumor MRI which ameliorates the otherwise short in vivo lifetimes of typical organic radicals-based CAs.
研究领域:
生物医学工程
·
纳米技术
·
材料科学
·
医学成像
·
药学
✓ 已验证
产品关联
DOI
高影响因子
Polymer Chemistry
·
2016
·Vol. 7
·期 14
·2511-2520
·
IF 5.687
Jiahui Su,Hong Huang,Yanyan Cui,Yingyin Chen,Xiaoxuan Liu
Two types of photoactive polymers with an alkoxyphenyl ketone moiety at their backbone centers were synthesized through atom transfer radical polymerization. A facile protocol for preparing α,ω-heterotelechelic polymers was developed, employing nitroxide with different functional groups (e.g., hydroxyl, propargyl, glycidyl, and polyethylene glycol) coupled with macromolecular radicals generated via the Norrish-type I photoreaction under mild UV irradiation from the said polymers. Experimental conditions such as solvent effects and irradiaton time were investigated to optimize the efficiency of reaction functionality. The number-average molecular weights of the photoactive polymers and α,ω-heterotelechelic polymers were determined by gel permeation chromatography. Material structures were further confirmed by 1H NMR and FT-IR spectroscopy. The end group activity of α,ω-heterotelechelic polymers obtained from this reaction was further demonstrated using the Cu-catalyzed azide–alkyne click reactions between PS-N3 and polystyrene capped with a propargyl group.
研究领域:
高分子化学
·
材料科学
·
光化学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）