JOURNAL OF MOLECULAR STRUCTURE
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2022
·
IF 3.841
Wei Qin,Xue Han,Junwei Wang,Xie Wang,Jianli Zhang
To design some excellent extractants for the separation of Zr(Ⅳ) and Hf(Ⅳ), a novel set of polyamidoamine dendrimers peripherally modified with salicylaldehyde (Abbreviated as PAMAM-SA) have been synthesized. UV-vis absorption and fluorescent spectrometry were used to study the selectivity of G.1.0, G2.0, G3.0 and G4.0 PAMAM-SA on Zr(Ⅳ) and Hf(Ⅳ) compared with other metal ions, and their extraction/separation performance on Zr(Ⅳ) and Hf(Ⅳ) was also investigated under different pH solutions. The results show that these dendrimers have superior selectivity on Zr(Ⅳ) and Hf(Ⅳ) as compared with Ca 2+ , Mg 2+ , Fe 3+ and Ni 2+ ions. The binding stoichiometry of G1.0, G2.0, G3.0 and G4.0 PAMAM-SA dendrimers with Zr(Ⅳ) is 1:4, 1:8, 1:10, 1:16 molar ratio determined by fluorescent titration respectively and the molar ratio of these dendrimers with hafnium is similar to that of zirconium. Both of the maximum extraction efficiency (EE%) on Zr(Ⅳ) and the separation coefficient (β Zr/Hf ) are following the order of G2.0-PAMAM-SA > G1.0-PAMAM-SA > G3.0-PAMAM-SA > G4.0-PAMAM-SA, and the maximum EE% on Zr(Ⅳ) is up to 98.9% and furthermore the β Zr/Hf is 1.52 for G2.0-PAMAM-SA at lower acid concentration compared with the reported extractants. The favorable higher EE% and β Zr/Hf indicate that G2.0-PAMAM-SA may be potentially employed as a highly selective and efficient extractant to enhance separating zirconium from hafnium.
研究领域:
化学
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材料科学
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DOI
高影响因子
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
·
2021
·
IF 5.279
Zhaohui Guo,Christian M. Pedersen,Pengfei Wang,Minjun Ma,Yingqing Zhao,Yan Qiao,Yingxiong Wang
The isomerization of d-glucose to d-fructose plays a key role in the biochemical and chemical conversion of biomass, and it is therefore desirable to develop and improve catalysts for this reaction. In this study, the environmentally friendly polymer poly(amidoamine) (PAMAM) dendrimer’s properties as catalysts for this isomerization are investigated. The experimental results showed that the PAMAM dendrimers, which have basic terminal groups, can effectively promote the d-glucose isomerization reaction. Under the optimized reaction conditions, d-fructose was generated with a 20% maximum yield and above 90% selectivity. 13C and 2H isotope experiments by NMR were carried out to explore the reaction mechanism. When the reaction was performed in D2O, the C1 signal of d-fructose changed to a triplet, which confirmed that the C1 carbon binds to a deuterium atom, i.e., isotopic exchange. It was also found that the deuterium atom at the C2 position of d-glucose-2-d1 cannot transfer to d-fructose. These data indicate that PAMAM dendrimers catalyze d-glucose isomerization through a mechanism, which includes deprotonation, formation of ene-diol intermediate, and proton exchange with the solvent.
研究领域:
生物化学
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绿色化学
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DOI
高影响因子
Biomaterials Science
·
2019
·Vol. 7
·期 9
·3918-3925
·
IF 5.251
Hailin Cong,Liping Zhou,Qingye Meng,Yixin Zhang,Bing Yu,Youqing Shen,Hao Hu
Polymer gels can be classified as chemical and physical gels, depending on the type of cross-link. Physical gels usually form by physical cross-linking, such as hydrogen bonding, van der Waals and/or p–p interactions, which can avoid the use of additional cross-linking agents. Polyamidoamine (PAMAM) dendrimers possess abundant active groups on their surfaces. Modified dendrimers have been used as versatile linkers in some projects. In this work, polymer gels composed of PAMAM dendrimers without any covalent bonding cross-linking agents were prepared. The number of amino groups and ester groups on the surface of the dendrimers was precisely regulated to help form hydrogen bonds between adjacent dendrimers. The prepared dendrimer-based polymer gels retain the properties of PAMAM dendrimers such as antibacterial properties, and the unique structures make the gels exhibit high compressive strengths but relatively low tensile strengths. Interestingly, the prepared gels show good anti-inflammatory properties in acute inflammation models of mice with ear edema. The inflammatory inhibition rate and hematoxylin–eosin (H&E) staining method were used to confirm the anti-inflammatory effect. This present study demonstrates that the dendrimer-based polymer gels achieved through hydrogen bonding could be a versatile platform for tissue engineering.
研究领域:
材料科学
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生物医学工程
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药理学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
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2018
·Vol. 135
·期 32
·46550
·
IF 1.901
Hongwei Zhao,Bing Liao,Fuwei Nian,Yangyang Zhao,Kun Wang,Hao Pang
In this work, a polyamidoamine dendrimer-based polycarboxylic superplasticizer (DPC) with a crosslinked emanative structure was synthesized via simple free radical polymerization. 1 H-nuclear magnetic resonance and Fourier transform infrared spectroscopy measurements were used for structural characterization. The fluidity, rheology behavior, and compressive strength of the cement/DPC samples were investigated in detail. The DPCs performed better dispersion and dispersion maintaining capabilities, stronger water reduction capability, and higher adsorption amounts than the conventional comb-shaped superplasticizer. The dispersive capacity of the DPC increased with an increasing generation of polyamidoamine dendrimers. Besides, compared with conventional comb-shaped superplasticizer, the addition of DPC led to a delayed and lowered heat flow peak on the hydration of cement paste at early age of hydration process. Furthermore, compressive strength results showed that the cement/DPC samples performed higher compressive strength than blank cement samples. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135 , 46550.
研究领域:
材料科学
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化学工程
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产品关联
DOI
高影响因子
Scientific Reports
·
2015
·Vol. 5
·期 1
·1-10
·
IF 5.578
Xie Jingjing,Wang Jichuang,Chen Hongning,Shen Weiyu,Sinko Patrick J.,Dong Haiyan,Zhao Rongli,Lu Yusheng,Zhu Yewei,Jia Lee
Circulation tumor cells (CTCs) in the bloodstream of early-stage cancer patients carry the important information about valuable biomarkers and biological properties of primary tumor. However, detection and capture of CTCs are challenging owing to their low concentrations. Traditional technologies have the limited detection sensitivity and the low capture efficiency. We, herein, report an effective approach to specifically bind and capture colon cancer HT29 cells by using multiple Sialyl Lewis X antibodies (aSlex)-conjugated PAMAM dendrimers. The conjugation was characterized by using atom force microscope, UV and fluorescence measurements. The capturing and regulating HT29 cells by the aSlex-coated dendrimer conjugate were analyzed by microscopy and flow cytometry. The results indicated that the conjugate showed the enhanced capture of HT29 cells in a concentration-dependent manner and the maximum capture efficiency of 77.88% was obtained within 1 h-exposure. G6-5aSlex-FITC conjugate showed capture efficiency better than FITC-G6-COOH-5aSlex conjugate. G6-5aSlex-FITC conjugate could specifically capture HT29 cells even when the target HT29 cells were diluted with the interfering cells (e.g., RBCs) to a low concentration. The capture resulted in a concentration-dependent restraint of the cell activity. In conclusion, the aSlex-coated dendrimer conjugate displayed the great potential in capturing and restraining colorectal CTCs in blood.
研究领域:
肿瘤学
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纳米医学
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生物化学
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产品关联
DOI
PubMed
高影响因子
Journal of Materials Chemistry B
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2013
·Vol. 1
·期 34
·4259-4266
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IF 0
Longgang Wang,Qinghua Yang,Guanglong Ma,Weifeng Lin,Zhen Wang,Mei Huang,Shengfu Chen
The dendrimer based synthetic enzyme mimic, so-called ‘dendrizyme’, has been of great interest since the early days of dendrimers. However, there is a lack of an effective way to obtain a natural enzyme mimic showing both good biocompatibility and high preservation of catalytic activity in biological complex medium simultaneously. Here we report a novel approach – the synthesis of a generation five dendrimer of poly(amido amine) (PAMAM) incorporating hemin through capping with carboxybetaine acrylamide (CBAA), which could function as peroxidase. Results showed that the nanocapsules of hemin using CBAA-modified PAMAM dendrimers (CBAA-H-PAMAM) exhibited excellent biocompatibility and full preservation of catalytic activity in bovine serum albumin (BSA) solution, compared with free hemin. Results indicated that the ultra-thin shell of zwitterionic CBAA groups reduced nonspecific interaction with proteins while it did not cause any obvious rise in hindrance to mass transfer. Furthermore, the synthetic peroxidase mimic (CBAA-H-PAMAM) exhibited remarkable temperature endurance as compared with natural proteins. Taken together, our results indicate that protein surface mimicking through CBAA attachment might open a new route for synthetic enzymes in biomedical related applications.
研究领域:
生物化学
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材料科学
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医学工程
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DOI
PubMed
MICROCHIMICA ACTA
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2022
·Vol. 189
·期 12
·1-10
·
IF 6.408
Dai Yin,Jiang Wei,Zheng Yani,He Pei,Zhu Ruizhi,Fei Jianwen,Xu Wei,Liu Chunbo,Hong Junli
A selective method for the determination of myosmine (a tobacco alkaloid) was developed using molecularly imprinted polymers (MIPs) based on Fe 3 O 4 @SiO 2 and PAMAM dendrimers. Fe 3 O 4 @SiO 2 with excellent magnetism and rapid separation performance was chosen as carrier for the MIPs. Moreover, the MIPs modified with PAMAM dendrimers exhibited a regular structure and abundant functional groups, which improve the efficiency of imprinting sites. The myosmine concentration was measured by HPLC with PDA detector, and the UV detection wavelength was set to 200 nm. The linear range of this assay was 13.2–400 mg/L with a correlation coefficient of 0.999, and the detection limit was 4.0 mg/L (S/N = 3). The MIPs have been used for the determination of myosmine in cigarettes, and the recovery range was 84.2–93.5%, with RSD values in the range 0.41–3.1%. In conclusion, our MIPs combine advantages of simple preparation and remarkable selectivity, which gives them excellent application prospects for the sensitive determination of trace myosmine in tobacco products. Graphical abstract
研究领域:
分析化学
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材料科学
·
烟草研究
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产品关联
DOI
PubMed
高影响因子
Journal of the Taiwan Institute of Chemical Engineers
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2021
·
IF 5.876
Zhihong Yin,Liandong Zhu,Fan Mo,Shuangxi Li,Dan Hu,Ruoyu Chu,Chenchen Liu,Chaozhen Hu
Cu (II) is one of the most harmful heavy metals in the environment, due to the hazardous effects to aquatic organisms, plants, animals, and human beings. In this work, a novel modified magnetic biochar (MBC@APTES-PAMAM) was prepared by PAMAM dendrimer for the removal of Cu (II). The analysis of structural properties identically demonstrated that the abundant -NH 2 groups were successfully loaded onto magnetic biochar surfaces. The sorption kinetics process of Cu (II) onto MBC@APTES-PAMAM was better fitted by the pseudo-second-order model. Langmuir isotherm model was better described for Cu (II) sorption process. MBC@APTES-PAMAM showed outstanding performances on Cu (II) removal, and the maximal adsorption amount was 251.81 mg/g. Adsorption experiment indicated that MBC@APTES-PAMAM had a higher Cu (II) removal efficiency under the pH range from 2 to 8. The adsorption capacity of Cu (II) onto MBC@APTES-PAMAM was decreased in the presence of competing ions. The existence of surfactant and humic acid had great influences on Cu (II) adsorption process. The Cu (II) adsorption mechanism was connected to the -NH 2 by complexation reaction, due to the increased electrostatic attraction and bridging influences. In addition, MBC@APTES-PAMAM also exhibited comparable removal performances for COD (70.82%), TN (71.10%), TP (100%), NH 3 N (55.03%) and Cu (II) (99.68%) in the practical treatment of landfill leachate. Overall, MBC@APTES-PAMAM is a green, low-cost, and high efficiency adsorbent for Cu (II) removal.
研究领域:
环境科学
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材料科学
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产品关联
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2023
·
IF 5.2
Siqin He,Bin Xu,Ying Liu,Xiaoshuang Yin,Wenzhong Yang,Yun Chen
Polyaminoamide (PAMAM) dendrimers with different generations from 1 G to 5 G were grafted on magnetic core-shell Fe 3 O 4 -SiO 2 composite particles , respectively. Using Fe 3 O 4 as a magnetic center and SiO 2 as the connecting layer, the PAMAM dendrimers with amino functional groups were modified on SiO 2 successfully, while laccase was immobilized to the surface of Fe 3 O 4 -SiO 2 -PAMAM x by covalent cross-linking using amide bond. Under the optimal conditions, the loading capacity of laccase reached 65.5 mg/g, and about 62.8 % of its initial activity of free laccase was reserved. Immobilized laccase degradated 2,4-dichlorophenol (2,4-DCP) with a degradation ratio of 91.5 % after 24 h. The degradation ratio of 82.9 % was maintained after 5 cycles of the operation, and when enhanced to the 10 cycles degradation, the degradation rate was still remained close to 80 %. Compared with free laccase, the comprehensive stability of immobilized laccase was improved significantly, and it displayed the excellent catalytic degradation ability for 2,4-DCP.
研究领域:
环境科学
·
生物技术
✓ 已验证
产品关联
DOI
高影响因子
Materials Science & Engineering C-Materials for Biological Applications
·
2018
·
IF 5.08
Yanshuai Cui,Bo Liang,Longgang Wang,Linlin Zhu,Jianxin Kang,Haotian Sun,Shengfu Chen
The surface charge of dendrimers is one of the key factors that determine their use in nanomedicine. Generation 5 poly(amido amine) dendrimers (G5 PAMAM) encapsulating with fluorescein sodium were employed to study the method to tune surface charge. Firstly, the surface primary amines were reacted with maleic anhydride to introduce double bonds. Then, l -cysteine and cysteamine were conjugated to these double bonds via thiol-ene additions in water, respectively. The surface charges of modified G5 PAMAMs were successfully controlled by tuning the molar ratio of L-cysteine to cysteamine. The surface charges of the resulting modified G5 PAMAMs varied from −16.0 mV to −3.7 mV at physiological pH. In addition, they showed good compatibility with proteins and cells compared with G5 PAMAM. Modified G5 PAMAMs and fibrinogen could coexist in solution without generating noticeable aggregation, while G5 PAMAM induces significant aggregation, indicating these modifications can effectively reduce the interaction force between G5 PAMAM and proteins. Furthermore, modified G5 PAMAMs exhibited negligible hemolysis, while G5 PAMAM caused severe hemolysis. The cytotoxicity assay demonstrated that modified G5 PAMAMs exhibited very low cytotoxicity to both HUVEC cells and KB cells (>90% cell viability) at high concentrations up to 2 mg/mL. The cellular uptake of them was much less efficient compared with that of G5 PAMAM. Moreover, the intravenous injected modified G5 PAMAMs were excreted by kidney with a relatively little accumulation in liver, confirming their good biocompatibility in vivo . It is expected that the modified G5 PAMAMs could be an excellent candidate for contrast agent carriers in the future.
研究领域:
纳米医学
·
生物材料学
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产品关联
DOI
PubMed
高影响因子
MICROCHEMICAL JOURNAL
·
2022
·
IF 5.304
Dandan Guo,Xiaoqian Zhou,Shaohua Huang,Yan Zhu
In this work, achiral metal organic frameworks (MIL-53(Al)–NH 2 ) were synthesized and functionalized with poly (amidoamine) (PAMAM) dendrimers. By dispersing PAMAM grafted MIL-53(Al)–NH 2 to water, the obtained solution exhibited high fluorescence intensity and stability. Due to the strong affinity interaction, fluorescence of the solution was quenched when Cu 2+ was added. Following the addition of lysine to the system, the quenched fluorescence intensity was partially restored based on the chelation between Cu 2+ and lysine. In this case, the fluorescent signal of MIL-53(Al)–NH 2 -PAMAM-Cu 2+ system became turn-on state. Furthermore, because of different chelating abilities with L-lysine and D-lysine, the system exhibited enantioselective fluorescence enhancement. Therefore, the PAMAM grafted MIL-53(Al)–NH 2 were successfully used for enantioselective fluorescence detection of lysine after being quenched by Cu 2+ . The method showed good linearity in both L/D-lysine detection (R 2 = 0.9976–0.9984) and ee values determination (R 2 = 0.9921). The detection limit of L-lysine and D-lysine were 7.52 and 12.2 μmol L −1 , respectively. Reliability of the method was verified by analysis of lysine enantiomers in spiked drinking water samples. Rapid enantioselective fluorescent imaging of lysine enantiomers showed great application prospects in test paper, diagnostic kit and vivo imaging system.
研究领域:
分析化学
·
生物化学
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产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2023
·
IF 9.5
Mengen Ma,Yilin Zeng,Yuzhao Yang,Cuiling Zhang,Yujiao Ma,Shaohang Wu,Chong Liu,Yaohua Mai
The wide-band-gap inorganic CsPbI2Br perovskite material provides a highly matched absorption range with the indoor light spectrum and is expected to be used in the fabrication of highly efficient indoor photovoltaic cells (IPVs) and self-powered low-power Internet of Things (IoT) sensors. However, the defects that cause nonradiative recombination and ion migration are assumed to form leakage loss channels, resulting in a severe impact on the open-circuit voltage (VOC) and the fill factor (FF) of IPVs. Herein, we introduce poly(amidoamine) (PAMAM) dendrimers with multiple passivation sites to fully repair the leakage channels in the devices, taking into account the characteristics of IPVs that are extremely sensitive to nonradiative recombination and shunt resistance. The as-optimized IPVs demonstrate a promising PCE of 35.71% under a fluorescent light source (1000 lux), with VOC increased from 0.99 to 1.06 V and FF improved from 75.21 to 84.39%. The present work provides insight into the photovoltaic mechanism of perovskites under full sun and indoor light, which provides guidance for perovskite photovoltaic technology with industrialization prospects.
研究领域:
材料科学
·
能源技术
·
光电子学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）