查找使用阿拉丁产品的科研文献

Rheological aspects in fabricating pullulan-whey protein isolate emulsion suitable for electrospraying: Application in improving β-carotene stability

Ben Niu,Ping Shao,Simin Feng,Dan Qiu,Peilong Sun

Beta-carotene has been used as a food colorant and functional ingredient, but these applications are limited due to its poor stability. The aim of this work was to improve the stability of β-carotene by encapsulating it in electrosprayed particles. The electrohydrodynamic behavior of pullulan solution was studied and the influence of encapsulation and core-to-wall ratio on the stability of β-carotene at different temperatures and relative humidity were investigated. The specific viscosity of the polymer solution increased linearly with the concentration until 5% w/w concentration. The critical entanglement concentration of the pullulan was found to be 4.58% wt. Among the various concentrations of pullulan studied, 3% w/w pullulan solution yielded spherical, monodisperse nanoparticles. Electrosprayed particles with 1:50 core-to-wall ratio had highest encapsulation efficiency. The rate of β-carotene loss displayed first order reaction kinetic within 14 days, while displayed diffusion limited mode after 14 days storage. The retention of β-carotene from the electrosprayed particles accelerated markedly with decreasing temperatures and relative humidity. This study provides a strategy for the preparation of promising electrosprayed particles to improve the stability of β-carotene.

Ru nanoclusters confined on α/β cobalt hydroxide nanosheets as efficient bifunctional oxygen electrocatalysts for Zn–air batteries

Yu Zhang,Ting Hu,Changwang Ke,Fengyan Han,Weiping Xiao,Xiaofei Yang

Rational regulation of the coordination environment of Ru active sites by employing layered transition metal hydroxides as the substrate could achieve high catalytic performance towards the oxygen evolution reaction (OER) and the oxygen reduction reaction (ORR). However, it is still challenging to clarify the interactions between the Ru catalysts and the layered transition metal hydroxides in different phases and also to unveil the mechanism responsible for the boosted performance. Herein, we report novel Ru nanocluster-decorated few-layer Co(OH)2 nanosheets, which are employed as a model to investigate the structure–property relationship between zero-dimensional (0D) noble metal catalysts and two-dimensional (2D) substrates toward electrochemical reactions. The obtained α-Co(OH)2-Ru catalyst exhibits a very low potential difference (ΔE) of 0.557 V between the half-wave potential towards the ORR and the potential at 10 mA cm−2 towards the OER, which is smaller than those of β-Co(OH)2-Ru (0.614 V), α-Co(OH)2 (0.774 V) and β-Co(OH)2 (0.897 V). Density functional theory (DFT) calculations further reveal that the reaction energy barrier of the rate-determining step of α-Co(OH)2-Ru is much smaller than those of β-Co(OH)2-Ru and Ru, implying that the strong electronic interactions between Ru nanoclusters and layered α-Co(OH)2 nanosheets contribute majorly to the enhanced catalytic performance. Furthermore, the optimized α-Co(OH)2-Ru nanohybrid is employed as the air electrode to assemble rechargeable Zn–air batteries, which possesses a power density of 187.8 mW cm−2 and a long-term durability of 400 cycles without obvious attenuation.

Experimental and molecular docking investigations on the inclusion mechanism of the complex of phloridzin and hydroxypropyl-β-cyclodextrin

Chun-Ling Zhang,Jie-Chao Liu,Wen-Bo Yang,Da-Lei Chen,Zhong-Gao Jiao

Phloridzin is a nutraceutical. Its use in food, medicine and cosmetics is limited because of its low aqueous solubility and stability limits, but it can be improved by complexing with cyclodextrins. In this study, we investigated the inclusion mechanism between phloridzin and hydroxylpropyl-β-cyclodextrin (HP-β-CD) using isothermal titration calorimetry (ITC), ultraviolet–visible spectrometry (UV), infrared spectrometry (IR), proton nuclear magnetic resonance spectroscopy ( 1 H NMR) and molecular docking simulations. The ITC results found that the equilibrium binding constant of HP-β-CD with phloridzin was higher than that of β-CD. Their inclusion was a spontaneous process with negative ΔG, ΔH and ΔS values. UV spectra showed that the aqueous solubility of phloridzin was enhanced by HP-β-CD. Our IR analysis verified the inclusion complexation of phloridzin into the HP-β-CD cavity. The Autodock determined that the substitution distribution of HP-β-CD influenced not only the orientation and depth degree of phloridzin within the cavity, but also the binding energies.

Linear-branched poly(β-amino esters)/DNA nano-polyplexes for effective gene transfection and neural stem cell differentiation

Yuheng Cao,Haobo He,Kaili Cao,Yongyang Liu,Dehua Huang,Tuanwei Li,Guangcun Chen

Controllable regulation of stem cell differentiation is a critical concern in stem cell-based regenerative medicine. In particular, there are still great challenges in controlling the directional differentiation of neural stem cells (NSCs) into neurons. Herein, we developed a novel linear-branched poly(β-amino esters) (S4-TMPTA-BDA-DT, STBD) through a two-step reaction. The synthesized linear-branched polymers possess multiple positively charged amine terminus and degradable intermolecular ester bonds, thus endowing them with excellent properties such as high gene load, efficient gene delivery, and effective gene release and transcription in cells. In the mCherry transfection test, a high transfection efficiency of approximately 70% was achieved in primary NSCs after a single transfection. Moreover, STBD also showed high biocompatibility to NSCs without disturbing their viability and neural differentiation. With the high gene delivery property, STBD is capable of delivering siRNA (shSOX9) expression plasmid into NSCs to significantly interfere with the expression of SOX9, thus enhancing the neuronal differentiation and maturation of NSCs. The STBD/DNA nano-polyplex represents a powerful non-viral approach of gene delivery for manipulating the differentiation of stem cells, showing broad application prospects in NSC-based regenerative therapy for treating neurodegenerative diseases.

Electrochemical biosensor for hydroxymethylated DNA detection and β-glucosyltransferase activity assay based on enzymatic catalysis triggering signal amplification

Huanshun Yin,Zhiqing Yang,Haiyan Wang,Yunlei Zhou,Shiyun Ai

A simple and sensitive electrochemical biosensor was fabricated for hydroxymethylated DNA detection and T4 β-glucosyltransferase activity assay based on the glycosylation of hydroxymethylated DNA and Hpa II restriction endonuclease system triggering signal amplification. After immobilizing double-stranded DNA (dsDNA) on the surface of carboxyl functionalized Fe 3 O 4 nanoparticle, the glycosylation reaction of hydroxymethylated cytosine can be performed with the catalytic effect of T4 β-glucosyltransferase using uridine diphosphoglucose as glucose donor. Then, 4-mercaptophenylboronic acid (4-MPBA) can be further reacted with glucose and captured on Fe 3 O 4 nanoparticle surface. After the dsDNA was digested by Hpa II, the fragment with 4-MPBA can be released from Fe 3 O 4 nanoparticle surface. After magnetic separation, this fragment can be further modified on gold electrode surface through the interaction between Au and −SH, which can result in a decreased electrochemical signal of [Fe(CN) 6 ] 3− . According to this detection strategy, the electrochemical biosensor showed high sensitivity with the low detection limits of 0.14   nM and 0.27 unit/mL for hydroxymethylated DNA and T4 β-glucosyltransferase. The fabricated biosensor also presented high selectivity and acceptable reproducibility. In addition, the inhibition activity of 4-phenylimidazole towards T4 β-glucosyltransferase was also investigated. This work provides a novel platform for hydroxymethylated DNA detection, T4 β-glucosyltransferase activity assay and its inhibition screening.

Hyaluronic-acid-based β-cyclodextrin grafted copolymers as biocompatible supramolecular hosts to enhance the water solubility of tocopherol

Parbeen Singh,Li Wu,Xiaohong Ren,Wei Zhang,Yan Tang,Yongli Chen,Andrew Carrier,Xu Zhang,Jiwen Zhang

Hyaluronic acid (HA), a common biopolymer found in the extracellular fluid, was grafted with β-cyclodextrin (β-CD) to form a composite polymer that could form inclusion complexes with tocopherol (VE), enhancing its water-solubility and serving as a model drug delivery system . Herein, different copolymers were prepared with varying HA:β-CD ratios and characterized. VE loading capacity was directly correlated with increased β-CD composition in the polymers and morphological changes were observed upon VE binding. The host materials and their VE inclusion complexes are not cytotoxic, and are thus useful for VE and drug delivery.

Silver Ion-Histidine Interplay Switches Peptide Hydrogel from Antiparallel to Parallel β-Assembly and Enables Controlled Antibacterial Activity

Yuchen Guo,Sha Wang,Hanhan Du,Xiaolong Chen,Hao Fei

Understanding the chemical absorption process of silver ions helps the rational design of functional materials for effective release to minimize unwanted toxicity. To this end, a histidine-containing aliphatic peptide (IH6) was designed to immobilize the silver ion (Ag+) through coordinate interaction. Using circular dichroism spectroscopy, Ag+ was found to dose-dependently induce parallel β-sheet conformation of IH6 to a saturation molar ratio of 1:2. A conformational switch of IH6 from antiparallel to parallel β-sheet assembly upon Ag + coordination was further revealed by Fourier transform infrared spectroscopy. The resultant Ag-IH6 hydrogel displayed substantially enhanced mechanical strength as well as controlled release of Ag+. Ag-IH6 hydrogel thus exhibited strong dose-dependent bactericidal activities that can be tuned selectively, sparing the cocultured human keratinocytes in normal. Overall, the study demonstrates an unusual silver ion-induced peptide conformational switch between β-structure subtypes and the bilateral effects on hydrogel-based chemical control of silver ion absorption and release, thus, revealing the potential in antibacterial applications.

Intradermal injection of icariin-HP-β-cyclodextrin improved traumatic brain injury via the trigeminal epineurium-brain dura pathway

Wei Yang,Yong-Hui Han,Heng-Cai Wang,Cui-Tao Lu,Xi-Chong Yu,Ying-Zheng Zhao

Using Multifunctional Peptide Conjugated Au Nanorods for Monitoring β-amyloid Aggregation and Chemo-Photothermal Treatment of Alzheimer's Disease

Meng Li,Yijia Guan,Andong Zhao,Jinsong Ren,Xiaogang Qu

Development of sensitive detectors of Aβ aggregates and effective inhibitors of Aβ aggregation are of diagnostic importance and therapeutic implications for Alzheimer's disease (AD) treatment. Herein, a novel strategy has been presented by self-assembly of peptide conjugated Au nanorods (AuP) as multifunctional Aβ fibrillization detectors and inhibitors. Our design combines the unique high NIR absorption property of AuNRs with two known Aβ inhibitors, Aβ15-20 and polyoxometalates (POMs). The synthesized AuP can effectively inhibit Aβ aggregation and dissociate amyloid deposits with NIR irradiation both in buffer and in mice cerebrospinal fluid (CSF), and protect cells from Aβ-related toxicity upon NIR irradiation. In addition, with the shape and size-dependent optical properties, the nanorods can also act as effective diagnostic probes to sensitively detect the Aβ aggregates. This is the first report to integrate 3 segments, an Aβ-targeting element, a reporter and inhibitors, in one drug delivery system for AD treatment.

High accessibility to active sites of hierarchical nanocrystalline Zr-β zeolite in ethanol–acetaldehyde conversion to 1,3-butadiene

Haoxi Jiang,Liping Yi,Guochao Yang,Lingtao Wang

Hierarchical Zr-β zeolite is a promising catalyst in the conversion of ethanol to 1,3-butadiene owing to the improved accessibility of active sites inside the zeolite to bulky substrates. Accordingly, hierarchical nanocrystalline Zr-β zeolite with sufficient intercrystalline mesoporosity and microporosity was prepared in this work via silanization-based hydrothermal synthesis. A systematic investigation was conducted to determine the effect of the secondary porosity on the textural, acidic and catalytic properties. The results suggested that neither acid amount, strength nor location varied with the additional secondary porosity. However, an appropriate proportion of micropores and mesopores would provide significant contributions to enhanced catalytic performance, arising from the available confined environment around the active sites inside the micropores, enhanced accessibility of such sites and improved diffusion of reactants and products due to mesopores.

Superior TRAIL gene expression and cancer cell apoptosis mediated by highly branched-linear poly(β-amino ester)s

Zhao Yitong,Bo Tao,Wang Chenfei,Yao Dingjin,Pan Chaolan,Xu Weiyi,Zhou Hao,Li Ming,Zhang Si

Extensive efforts have been dedicated to enhancing the expression of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) in cancer cells for the development of effective cancer treatments. However, highly safe and efficient delivery of TRAIL gene remains a significant challenge, especially using cationic polymers. Here, a series of highly branched-linear poly(β-amino ester)s (H-LPAEs) are developed through a unique oligomer branching strategy. H-LPAEs exhibit a more uniform distribution of linear segments and branching units, leading to excellent DNA condensation and favorable physicochemical properties of H-LPAE/DNA polyplexes. In SW1353 and BMSC cells, the optimized H-LPAEs, H-LPAE B4−S5−TMPTA , achieves superior gene transfection efficiency of 58.0% and 33.4%, which were 2.5-fold and 2.0-fold higher than that of the leading commercial gene transfection reagent, Lipofectamine 3000. Excitingly, H-LPAE B4−S5−TMPTA mediated 56.7% and 28.1% cell apoptosis in HepG2 cells and HeLa cells highlighting its potential application in cancer gene therapy. In addition, locally administered H-LPAE B4−S5−TMPTA delivered TRAIL DNA to HepG2 xenograft tumors and inhibited tumor growth in vivo. This study not only proposes a novel strategy for synthesizing poly(β-amino ester)s with a unique branched-linear topology but also identifies a promising candidate for highly efficient TRAIL gene transfection.

USP43 impairs cisplatin sensitivity in epithelial ovarian cancer through HDAC2-dependent regulation of Wnt/β-catenin signaling pathway

Pei Lipeng,Zhao Feng,Zhang Yi

Epithelial ovarian cancer (EOC) is the leading cause of cancer death all over the world. USP43 functions as a tumor promoter in various malignant cancers. Nevertheless, the biological roles and mechanisms of USP43 in EOC remain unknown. In this study, USP43 was highly expressed in EOC tissues and cells, and high expression of USP43 were associated with a poor prognosis of EOC. USP43 overexpression promoted EOC cell proliferation, enhanced the ability of migration and invasion, decreased cisplatin sensitivity and inhibited apoptosis. Knockdown of USP43 in vitro effectively retarded above malignant progression of EOC. In vivo xenograft tumors, silencing USP43 slowed tumor growth and enhanced cisplatin sensitivity. Mechanistically, USP43 inhibited HDAC2 degradation and enhanced HDAC2 protein stability through its deubiquitylation function. USP43 diminished the sensitivity of EOC cells to cisplatin through activation of the Wnt/β-catenin signaling pathway mediated by HDAC2. Taken together, the data in this study revealed the functions of USP43 in proliferation, migration, invasion, chemoresistance of EOC cells, and the mechanism of HDAC2-mediated Wnt/β-catenin signaling pathway. Thus, USP43 might serve as a potential target for the control of ovarian cancer progression.