INTERNATIONAL JOURNAL OF PHARMACEUTICS
·
2016
·
IF 3.994
Kang Chen,Qing Chen,Kuanglei Wang,Jia Zhu,Weinan Li,Wenpan Li,Lipeng Qiu,Guannan Guan,Mingxi Qiao,Xiuli Zhao,Haiyang Hu,Dawei Chen
The present report describes the synthesis of a hydroxyl terminal PAMAM dendrimer (PAMAM-OH) derivative (PAMSPF). The hydroxyls of PAMAM-OH were attached to S-Methyl- l -cysteine (SMLC) via an acid-labile ester bond, named as β-thiopropionate bond, followed by modification with folic acid (FA) through a polyethylene glycol (PEG) linker. The degrees of attachment of SMLC and FA to the PAMAM-OH backbone were 83.9% and 12.8%, respectively. PAMSPF could condense DNA to form spherical nanoparticles with particle sizes of ∼200 nm and remain stable in the presence of heparin and nuclease . The β-thiopropionate bond in PAMSPF was hydrolyzed completely and the DNA release rate was 95.8 ± 3.3% after incubation under mildly acidic conditions at 37 °C for 3 h. PAMSPF/DNA was less cytotoxic to KB and HepG2 cells and exhibited a higher gene transfection efficiency than native PAMAM/DNA. The uptake assays showed that PAMSPF/DNA entered KB cells within 0.5 h through folate receptor-mediated endocytosis and escaped from endosomes within 2 h. In addition, PAMSPF/DNA displayed long circulation time along with excellent targeting of tumor sites in vivo. These findings demonstrate that PAMSPF is an excellent carrier for safe and effective gene delivery.
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Reaction Kinetics Mechanisms and Catalysis
·
2017
·Vol. 122
·期 1
·525-538
·
IF 1.264
Li Xin,Meng Fanhui,Cheng Yang,Gao Yuan,Li Zhong
Mesoporous silica (SiO 2 ) supported highly dispersed Ni catalysts with ZrO 2 and surfactant β-cyclodextrin (CD) were prepared by the impregnation method, and their catalytic performance for three-phase methanation of CO were evaluated. It is shown that ZrO 2 promotes the dispersion of Ni species on mesoporous SiO 2 , leading to the increase in Ni dispersion and methanation activity. For the ZrO 2 content, the optimum is 5 wt%. Moreover, when adding CD in the preparation of Ni5Zr/SiO 2 catalyst, CD was found effectively enhanced the dispersion of Ni species and interaction between Ni species and support, leading to a smaller size of NiO particles and more exposed active surfaces, which promotes the CO adsorption capacity. As the molar ratio of CD/Ni rises, the crystallite size of metallic Ni decreased. Ni5Zr/SiO 2 (1:5) catalyst prepared with 5 wt% ZrO 2 and 1:5 molar ratio of CD/Ni shows the optimal catalytic activity for the three-phase CO methanation reaction. This is because of the highest dispersion of metallic Ni and smallest size of NiO particles.
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MICROCHIMICA ACTA
·
2016
·Vol. 183
·期 10
·2823-2830
·
IF 4.831
Zhong Yaping,Deng Chun,He Yu,Ge Yili,Song Gongwu
The authors describe a method for increasing the peroxidase-like catalytic properties of copper nanoclusters (Cu-NCs) that are used in non-enzymatic assays. The Cu-NCs were prepared by utilizing 6-thio-β-cyclodextrin as both the template and as effective modulators for increasing the peroxidase-like properties of the Cu-NCs. The β-CD-coated Cu-NCs have an average diameter of 2 nm, are stable in aqueous solutions, display strong fluorescence with excitation/emission peak wavelengths of 360/450 nm, and possess peroxidase-like catalytic activity which makes them a useful enzyme mimic. We have applied the findings to non-enzymatic photometric determination (at 650 nm) of (a) H 2 O 2 in the concentration range of 0.02 to 10 mM using the β-CD/Cu-NC assisted oxidation of tetramethylbenzidine by H 2 O 2 , and (b) glucose in the concentration range of 0.04 to 20 mM after addition of glucose oxidase and formation of H 2 O 2 . The detection limits (at an S/N ratio of 3) are 0.2 μM for H 2 O 2 and 0.4 μM for glucose. The β-CD coating is found to result in a strong increase in the reaction rate, probably because the cavity of β-CD acts as a pocket for the recognition and catalysis of substrate. Hence, the binding specificity becomes similar to that of natural enzymes.
The peroxidase-like catalytic activity of Cu-NCs in non-enzymatic sensors is strongly enhanced by utilizing mono-6-thio-β-cyclodextrin (mono-6-SH-β-CD) as both the template molecule and the effective rate modulator.
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BIOSENSORS & BIOELECTRONICS
·
2017
·
IF 7.78
Hong Ke,Haifeng Sha,Yinfang Wang,Weiwei Guo,Xin Zhang,Zhiming Wang,Chusen Huang,Nengqin Jia
Electrochemiluminescent (ECL) assay has gradually drawn increasing interest in the biomedical analysis. This paper proposed a new methodology for ultrasensitive and facile detection of Alzheimer's disease marker β-amyloid (Aβ) by fabricating a sandwich-type ECL sensing platform. Herein, electrochemiluminescence resonance energy transfer (ECL-RET) was employed to determine Aβ concentration, which can be attributed to the quenching effect from RET between Ru(bpy) 3 2+ and gold nanorods (GNRs) acting as ECL-RET electron donor and acceptor, respectively. In this protocol, mesoporous carbon nanospheres were adopted to immobilize ECL reactant Ru(bpy) 3 2+ and antibody via nafion to acquire the RET donor nanocomposites (MOCs/nafion/Ru(bpy) 3 2+ /antibody), which were tightly interconnected with epoxy group functionalized Fe 3 O 4 nanoparticles . It is of vital importance that GNRs with exquisite rod shape were synthesized and exhibited a typical absorption peak at 650 nm to quench ECL signal of Ru(bpy) 3 2+ effectively. In addition, the ECL emission decreased linearly with the logarithm of Aβ concentration in a wide linear range from 1.0 × 10 −5 to 100 ng/mL with a detection limit of 4.2 × 10 −6 ng/mL. Furthermore, distinctive and desirable properties were verified to declare the promise for being applicable to analyze the Aβ content in real Alzheimer's cerebrospinal fluid samples with satisfactory results.
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INTERNATIONAL JOURNAL OF POLYMER ANALYSIS AND CHARACTERIZATION
·
2017
·
IF 0
Shouhui Yi,Bo Yang,Rongqiang Liao
A series of novel pendant polymers, composed of a poly(ε-lysine) (ε-PL) (w: 4,000 g mol−1) main chain and three kinds of amino acid β-cyclodextrin (CD) derivatives, were prepared by 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride and N-hydroxysuccinimide-assisted synthesis and characterized by nuclear magnetic resonance, Fourier transform infrared spectroscopy, thermal gravimetric analysis, X-ray power diffraction, and scanning electron microscopy. Cytotoxicity and moisture absorption of the pendant polymers were also tested. Compared with ε-PL, all the pendant polymers exhibited lower moisture absorption and cytotoxicity. The synthesis method of the pendant polymers is simple, feasible, and has good practicability. We suggest these polymers have potential applications in many fields, especially in gene delivery vector and drug delivery systems.
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ANALYTICAL CHEMISTRY
·
2016
·
IF 5.886
Fengli Qu,Minghui Yang,Avraham Rasooly
The protease BACE1 (the β-site amyloid precursor protein cleaving enzyme 1) catalyzes the first step in the synthesis of β-amyloids (Aβ), peptides that accumulate in the brain in Alzheimer’s disease (AD). Measurement of BACE1 activity is important for the development of BACE1 inhibitors to slow or stop AD. To measure BACE1 cleavage of the electrode-immobilized substrate peptide, we developed a redox-generating hydroxyapatite (HAP) probe which generates electrochemical current by reaction of the nanoparticle with molybdate (MoO42–). The probe combines alkaline phosphatase (ALP) for dual signal amplification and Aβ antibody to bind the probe to the immobilized peptide substrate on the surface of the electrode. We measured the activity of BACE1 at concentrations ranging from 0.25 to 100 U/mL. The use of the dual-signal HAP–ALP probe increased the signal by an order of magnitude compared to HAP-only probe, enabling detection limits as low as 0.1 U/mL. To measure the inhibition of BACE1 activity, the BACE1 inhibitor OM99-2 was added to 25 U/mL of BACE1 in concentrations ranging from 5 to 150 nM. The observed detection limit of inhibition is 10 nM of OM99-2. These results demonstrate the capabilities of this novel biosensor to measure BACE1 activity and inhibitors of BACE1 activity. To the best of our knowledge this is the first report that reaction of HAP nanoparticles with molybdate can generate electrochemical current. This dual signal amplification strategy can be extended to other electrochemical assays and adapted for wide applications.
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INTERNATIONAL JOURNAL OF ONCOLOGY
·
2017
·Vol. 51
·期 2
·615-624
·
IF 3.079
Saisai Wang,Yong Shen,Runfeng Qiu,Zhiliang Chen,Zhehang Chen,Wenbin Chen
Accumulating evidence shows that 18 β-glycyrrhetinic acid (GRA) has antitumor activities in breast, ovarian cancer and leukemia, while its role in colorectal cancer remains unknown. In the present study, we investigated the effect of GRA in colorectal cancer cells LoVo, SW480 and SW620 and studied the underlying molecular mechanisms. Results showed that GRA had potent inhibitory effects on colorectal cancer cell proliferation in a dose- and time-dependent manner in vitro and in vivo. Growth inhibition was mediated by pro-apoptosis, as evident from Annexin V-FITC staining, the reduced expression of survivin and the induced expression of cleaved PARP. Furthermore, GRA treatment resulted in marked reduction of cell migration, invasion and wound healing capability, accompanying by the downregulated MMP expression. Moreover, GRA decreased the protein levels of p-PI3K, p-AKT, p-STAT3, p-JNK, p-p38 and p-NF-κB p65, of which the phosphorylation of PI3K and STAT3 decreased as early as 2 h after the GRA treatment. These results suggest that regulation of the apoptosis, invasion and migration of colorectal cancer cells by GRA might be through suppressing PI3K and STAT3 signaling pathways. the present study indicated that GRA could be a potential effective therapy for patients with colorectal cancer.
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JOURNAL OF MOLECULAR STRUCTURE
·
2017
·
IF 1.753
Xin Gao,Hongna Bi,Huijun Zuo,Jingjing Jia,Lin Tang
The purpose of this study was to explore the effect of residue tetracycline hydrochloride (TCH) in milk on molecular structure and activity of β-Gal. Inhibition kinetics assay showed the TCH inhibited β-Gal activity reversibly in a competitive manner. In addition, differences in the activity of β-Gal in the absence and presence of TCH as a function of pH and temperature were found although the optimum pH and temperature of β-Gal remained similar. Fluorescence experiment results showed that TCH effectively quenched the intrinsic fluorescence of β-Gal via static quenching. Thermodynamic parameters delineated the major roles of electrostatic forces played between β-Gal and TCH. Additionally, synchronous fluorescence and circular dichroism spectra (CD spectra) results indicated the secondary structure of β-Gal was changed due to the formation of β-Gal−TCH complexes. The molecular docking further revealed that TCH interacted with some amino acid residues of β-Gal, affecting the active site of the enzyme and thus leading to change in enzyme activity . These alterations in conformation and activity of β-Gal should be taken into consideration while using β-Gal for producing oligosaccharide prebiotics on dairy industries.
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RSC Advances
·
2017
·Vol. 7
·期 31
·19205-19210
·
IF 3.108
Jing Yan,Honghu Yao,Junhao Li,Shiman He,Qili Wu,Xianfeng Yang,Wasim Ullah Khan,Jianxin Shi,Mingmei Wu
To meet the increasing requirement, much effort has been devoted to enhance the emission intensity and tailor the emission color of rare earth phosphors. However, limited contributions have been made to the up-conversion (UC) of nanorods by complete epitaxial growth on each facet to achieve this requirement. In this study, we propose a facile epitaxial growth route to grow anisotropic hexagonal β-NaYF4:Yb3+/Ho3+@β-NaYbF4:Er3+, β-NaYF4:Yb3+/Ho3+@β-NaYF4, and β-NaYbF4:Er3+@β-NaYF4 core/shell nanorods, which were realized by adding hexagonal β-NaYF4:Yb3+/Ho3+ or β-NaYbF4:Er3+ nanorods as a core-nanostructure into a solution containing cubic α-NaYbF4:Er3+ or α-NaYF4 nanoparticles as the shell-precursor. During epitaxial growth-induced phase transformation, the precursor nanoparticles disappeared gradually in the solution and consequently corresponding β-phased shell yielded on each outer facet of each β-phased nanorod core. Eventually, the nanorod core was covered completely with a uniformly grown β-NaYbF4:Er3+ or β-NaYF4 shell. The UC emission of either β-NaYF4:Yb3+/Ho3+ or β-NaYbF4:Er3+ core can be enhanced by the outer shell due to the decrease in the number of surface defects. In addition, tailored UC emissions could be obtained by controlling the shell components and thickness, typically in the core/shell nanorods of β-NaYF4:Yb3+/Ho3+@β-NaYbF4:Er3+. The tunable colors with improved emission in these core/shell nanorods may find wider applications in multicolor labeling and anti-counterfeiting.
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LUMINESCENCE
·
2017
·Vol. 32
·期 7
·1221-1226
·
IF 1.509
Xuanping Tan,Jidong Yang,Qiong Yang,Qin Li
In this work, a highly sensitive, citrate anion-capped gold nanoparticles (AuNPs)-based assay for the determination of propranolol in real samples with resonance Rayleigh scattering (RRS) and colorimetry was developed. When AuNPs were prepared by the sodium citrate reduction method, citrate anions self-assembled on the surface of AuNPs to form supramolecular complex anions. In BR 4.6 buffer solution, propranolol was positively charged and could bind with AuNPs to form larger aggregates through electrostatic force and hydrophobic effects. This results in remarkable enhancement of the RRS intensity and a color change in the AuNPs solution from red to blue via purple. Thus, a highly sensitive RRS and colorimetric assay the for detection of propranolol was developed with a linear range of 0.2–5.2 and 8–112 ng/ml, respectively. In addition, no difference was seen when comparing R -propranolol with S -propranolol, therefore, this method could not be used in the recognition of chiral propranolol. However, upon addition of other β-adrenergic blockers, no phenomenon like that seen with propranolol was observed, meaning that this method can be used for determining the presence of propranolol in a mixture β-adrenergic blockers. Finally, the optimum conditions, factors influencing the reaction, its mechanism and the reasons for enhancement of the RRS were discussed.
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高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Yuchen Li,Qi Wang,Xuetong Zhao,Binlang He,Yongjian Xiao,Jing Guo,Lijun Yang,Ruijin Liao
Sodium β- alumina (SBA) electrolytes are among the most excellent candidates for all-solid-state batteries due to their high electrochemical performances and low cost of sodium resources. However, thermally sintering at above 1400 °C is required to fabricate high dense SBA electrolytes, thus giving rise to a huge energy consumption. Here, dense SBA electrolytes and (1- x )SBA- x NaPF 6 ( x = 5, 10, 15, 20 wt%) composites were fabricated using cold sintering process (CSP) below 300 °C with 2 mol/L NaOH solution as transient chemistry. The ionic conductivity of SBA electrolytes is significantly enhanced from 5.53×10 -6 S cm -1 to 5.91 × 10 −4 S cm −1 as 15 wt% NaPF 6 was introduced to the composite, which is comparable with the SBA sintered above 1400 °C. CSP may provide a promising approach for the fabrication of solid-state electrolytes by avoiding the detrimental impact of high temperature heat treatment.
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CHEMOSPHERE
·
2024
·
IF 8.1
Yalong Duan,Ruxia Zhang,Pengfei Han,Ngie Hing Wong,Jaka Sunarso,Shaomin Liu,Jiang Yu
This work reports the ion exchange fabrication of maghemite (γ-Fe 2 O 3 ) modified NaY zeolite (Fe 2 O 3 @Y) with bifunction of adsorption and catalysis. The Fe 3+ successfully replaced the Na + in the β cage of zeolite in the ion exchange process and coordinated with framework oxygens to form magnetic γ-Fe 2 O 3 . Therefore, most of the γ-Fe 2 O 3 particles were confined in the β cages, which resulted in the high dispersal and stability of the catalyst. The Fe 2 O 3 @Y could remove methylene blue (MB) model pollutants up to 59.02 and 61.47% through the adsorption and catalysis process, respectively. The hydrogen bond between the OH − ions around the Fe 2 O 3 @Y surface and the N and O presented in the MB molecules enabled the chemical adsorption to MB, which accorded with the pseudo-second-order kinetic model. Further, the H + existed in the solution and the β cage of zeolite promoted the collapse of micro-nano bubbles (MNBs). Then, the γ-Fe 2 O 3 catalyst would be activated by high temperature and oxidated OH − to produce hydroxyl radicals for pollutant degradation . Thus, pollutant removal was attributed to the combined effects of adsorption and catalysis in the Fe 2 O 3 @Y + MNB system. In this work, the Fe 2 O 3 @Y was demonstrated as a potentially magnetic adsorbent or MNB catalyst for wastewater treatment .
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