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Multiple effects of polydopamine nanoparticles on Cu^(2+)-mediated Alzheimer's β-amyloid aggregation

Chinese Journal of Chemical Engineering 2023年第2期54卷 144-152页

作者： Xueqing Chen Weiqun Gao Yan Sun Xiaoyan Dong department of Biochemical Engineering School of Chemical Engineering and Technology and Key Laboratory of Systems Bioengineering and Frontiers Science Center for Synthetic Biology(Ministry of Education)Tianjin UniversityTianjin 300350China

Deposition of β-amyloid protein(Aβ) is the main hallmark of Alzheimer's disease(AD), and it has been well recognized that Cu^(2+)-mediated Aβ aggregation plays a crucial role in AD pathological ***^(2+)binding to Aβ can promote the production of reactive oxygen species(ROS) through Fenton-like reactions and produce more toxic Aβ-Cu^(2+)species under Cu^(2+)stimulation. Thus, the development of nanomaterials that can inhibit Cu^(2+)-mediated Aβ aggregation and degrade Aβ-Cu^(2+)complexes is considered an effective strategy for the prevention and treatment of AD. In this study, polydopamine nanoparticles(PDA NPs) were prepared and the results reveal that PDA NPs potently inhibit Cu^(2+)-mediated Aβaggregation and effectively reduce the formation of Aβ-Cu^(2+)complexes. In vitro experiments show that PDA NPs efficiently eliminate ROS generation catalyzed by Cu^(2+)or Aβ-Cu^(2+)complexes, thus rescuing cultured cells by reducing intracellular ROS levels. More importantly, PDA NPs can depolymerize Aβ-Cu^(2+)complexes, and the degradation of Aβ-Cu^(2+)complexes is promoted by near-infrared light irradiation due to their high photothermal conversion ability. In vivo studies reveal that PDA NPs significantly reduce the deposition of Aβ plaques in the presence of Cu^(2+)and extend the lifespan of AD nematodes from 11 to 14 d. Thus, the PDA NPs developed herein are multifunctional against Cu^(2+)-mediated Aβ aggregation for the potential prevention and treatment of AD.

关键词： Protein Aggregation Nanoparticles Photothermal therapy Reactive oxygen species Cu^(2+)chelator

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Facile purification and immobilization of organophosphorus hydrolase on protein-inorganic hybrid phosphate nanosheets

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Chinese Journal of Chemical Engineering 2023年第4期56卷 119-125页

作者： Zhenfu Wang Jie Gao Qinghong Shi Xiaoyan Dong Yan Sun department of Biochemical Engineering School of Chemical Engineering and Technology and Key Laboratory of Systems Bioengineering and Frontiers Science Center for Synthetic Biology(Ministry of Education)Tianjin UniversityTianjin 300350China

Oriented immobilization of enzymes helps to maintain their native structure and proper orientation for high-performance engineering to meet extensive biocatalysis ***,the supporting materials used for orientated immobilization are usually costly or complicated in preparation,affecting their practical *** this work,a facile purification and immobilization method was proposed for enzyme immobilization based on organic-inorganic hybrid calcium phosphate nanocrystal(Ca Ps)induced by Cu^(2+) modified bovine serum albumin(BSA-Cu).Then,the as-prepared hybrid calcium phosphate nanosheet,BSA-Cu@Ca Ps,was utilized for one-pot purification and immobilization of His-tagged organophosphorus hydrolase(OPH)by metal-affinity binding to the incorporated ***-Cu@Ca PsOPH exhibited enhanced p H stability and thermal stability compared to the free ***,BSA-Cu@Ca Ps-OPH could retain more than 75%and 56%of initial activity after reuse 5 and 10 times,*** results demonstrated that this facile strategy was promising for the effective biodegradation of organophosphorus pesticides with the immobilized enzyme.

关键词： Calcium phosphate nanocrystal(CaPs) Biomimetic mineralization Organophosphorus hydrolase(OPH) Oriented immobilization Hydrolysis Methyl parathion

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Rational surface charge engineering of haloalkane dehalogenase for boosting the enzymatic performance in organic solvent solutions

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Chinese Journal of Chemical Engineering 2024年第1期65卷 276-285页

作者： Yin Wu Yan Sun department of Biochemical Engineering School of Chemical Engineering and Technology and Key Laboratory of Systems Bioengineering and Frontiers Science Center for Synthetic Biology(Ministry of Education)Tianjin UniversityTianjin 300350China

Biocatalysis in organic solvents(OSs)has numerous important applications,but native enzymes in OSs often exhibit limited catalytic ***,we proposed a computation-aided surface charge engineering strategy to improve the catalytic performance of haloalkane dehalogenase DhaA in OSs based on the energetic analysis of substrate binding to the DhaA *** variants with enhanced OS resistance were obtained by replacing negative charged residues on the surface with positive charged residue(Arg).Particularly,a four-substitution variant E16R/E93R/E121R/E257R exhibited the best catalytic performance(five-fold improvement in OS resistance and seven-fold half-life increase in 40%(vol)dimethylsulfoxide).As a result,the overall catalytic performance of the variant could be at least 26 times higher than the wild-type *** spectroscopy and molecular dynamics simulation studies revealed that the residue substitution mainly enhanced OS resistance from four aspects:(a)improved the overall structural stability,(b)increased the hydrophobicity of the local microenvironment around the catalytic triad,(c)enriched the hydrophobic substrate around the enzyme molecule,and(d)lowered the contact frequency between OS molecules and the catalytic *** findings validate that computationaided surface charge engineering is an effective and ingenious rational strategy for tailoring enzyme performance in OSs.

关键词： Surface charge engineering Organic solvent resistance Molecular dynamics simulation Haloalkane dehalogenase

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Adaptive Memetic Algorithm with Dual-Level Local Search for Cooperative Route Planning of Multi-Robot Surveillance systems

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Complex System Modeling and Simulation 2024年第2期4卷 210-221页

作者： Hao Cheng Jin Yi Wei Xia Huayan Pu Jun Luo the State Key Laboratory of Mechanical Transmission for Advanced equipment Chongqing UniversityChongqing 400044China the department of Electronics Information and BioengineeringPolitecnico di MilanoMilano 20133Italy

The heightened autonomy and robust adaptability inherent in a multi-robot system have proven pivotal in disaster search and rescue,agricultural irrigation,and environmental *** study addresses the coordination of multiple robots for the surveillance of various key target positions within an *** involves the allocation of target positions among robots and the concurrent planning of routes for each *** tackle these challenges,we formulate a unified optimization model addressing both target allocation and route ***,we introduce an adaptive memetic algorithm featuring dual-level local search *** algorithm operates independently among and within robots to effectively solve the optimization problem associated with *** proposed method’s efficacy is substantiated through comparative numerical experiments and simulated experiments involving diverse scales of robot teams and different target positions.

关键词： multi-robot system surveillance memetic algorithm

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Excitation of the abdominal ganglion affects the electrophysiological activity of indirect flight muscles of the honeybee Apis mellifera

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Insect Science 2024年第4期31卷 1187-1199页

作者： Haojia Ding Shaoze Yan State Key Laboratory of Tribology in Advanced equipment(SKLT) Division of Intelligent and Biomechanical SystemsDepartment of Mechanical EngineeringTsinghua UniversityBeijingChina

Our understanding of the nervous tissues that affect the wing flapping of insects mainly focuses on the brain,but wing flapping is a rhythmic movement related to the central pattern generator in the ventral nerve *** verify whether the neural activity of the abdominal ganglion of the honeybee(Apis mellifera)affects the flapping-wing flight,we profiled the response characteristics of indirect flight muscles to abdominal ganglion ***,a change in the neural activity of ganglion 3 or ganglion 4 has a stronger effect on the electrophysiological activity of indirect flight muscles than that of ganglion *** electrophysiological activity of vertical indirect flight muscles is affected more by the change in neural activity of the abdominal ganglion than that of lateral indirect flight ***,the change in neural activity of the abdominal ganglion mainly causes the change in the muscular activity of indirect wing muscles,but the activity patterns change relatively little and there is little change in the complicated *** work improves our understanding of the neuroregulatory mechanisms associated with the flapping-wing flight of honeybees.

关键词： abdominal ganglion electromyography flapping wing honeybee indirect flight muscle muscular activity

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Generatrix shape optimization of stiffened shells for low imperfection sensitivity

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Science China(Technological Sciences) 2014年第10期57卷 2012-2019页

作者： WANG Bo HAO Peng LI Gang WANG XiaoJun TANG XiaoHan LUAN Yu State Key Laboratory of Structural Analysis for Industrial equipment Department of Engineering Mechanics Dalian University of Technology Beijing Institute of Astronautical systems Engineering

According to previous studies,stiffened shells with convex hyperbolic generatrix shape are less sensitive to *** this study,the effects of generatrix shape on the performances of elastic and plastic buckling in stiffened shells are ***,a more general description of generatrix shape is proposed,which can simply be expressed as a convex B-spline curve(controlled by four key points).An optimization framework of stiffened shells with a convex B-spline generatrix is established,with optimization objective being measured in terms of nominal collapse load,which can be expressed as a weighted sum of geometrically imperfect *** effectiveness of the proposed framework is demonstrated by a detailed comparison of the optimum designs for the B-spline and hyperbolic generatrix *** decrease of imperfection sensitivity allows for a significant weight saving,which is particularly important in the development of future heavy-lift launch vehicles.

关键词： stiffened shell collapse imperfection sensitivity generatrix shape optimization

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Zirconium-mediated Synthesis and Crystal Structure of 3,6-Diiodo-4,5-dialkyl-phthalic Acid Dimethyl Ester

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Chinese Journal of Structural Chemistry 2015年第9期34卷 1347-1356页

作者：李旭东王会李君秋门奕灿曲红梅 Key Laboratory of systems bioengineering Ministry of EducationTianjin Key Laboratory of Biological and Pharmaceutical EngineeringDepartment of Pharmaceutical EngineeringSchool of Chemical Engineering and TechnologyTianjin University

A novel series of para-diiodobenzene derivatives, 3,6-diiodo-4,5-dialkyl-phthalic acid dimethyl esters, were prepared via cycloaddition of two TMS-substituted alkynes and dimethyl acetylenedicarboxylate, which was mediated by zirconocene. After iodination, three new compounds of 3,6-diiodo-4,5-dimethyl（dipropyl, dibutyl）-phthalic acid dimethyl esters （3a, 3b, 3c） were synthesized in high region-selectivity and yields, and characterized by NMR. The crystal structures were determined by single-crystal X-ray diffraction. The crystal of 3a （C12H121204, Mr = 474.02） belongs to the triclinic system, space group Pi with a = 7.6238（10）, b = 9.4571（12）, c = 10.8221（14） A, a = 66.611（10）, fl = 88.511（12）, 7 ： 77.604（11）% V= 697.93（16） A3, Z= 2, F（000） = 444, Dc = 2.256 mg/m3, g = 4.509 mm-1, T=133（2） K, S = 1.014, R = 0.0229 and wR = 0.0547 for 2644 observed reflections with I 〉 20（/）; the crystal of 3b （C16H201204, Mr - 530.12） is of triclinic system, space group Pi with a = 9.4122（19）, b = 10.626（2）, c = 11.353（2） A, a = 97.90（3）, fl = 113.83（3）, y = 110.22（3）°, V= 922.6（3） A3, Z- 2, F（000） = 508, Dc - 1.908 mg/m3, g = 3.422 mm-1, T = 113（2） K, S = 1.115, R = 0.0428 and wR = 0.1072 for 3971 observed reflections with I〉 20（/）; the crystal of 3c （ClsH241204, Mr = 558.17） belongs to the monoclinic system, space group P21/c with a = 26.396（2）, b = 8.7560（8）, c = 25.7970（18） A, fl = 91.721（4）o, V= 5959.6（8） A3, Z = 12, F（000） = 3240, Dc = 1.866 mg/m3,/z = 3.184 mm-l, T= 113（2） K, S = 1.154, R = 0.0424 and wR = 0.0766 for 13056 observed reflections with I 〉 20（/）.

关键词： zirconocene 3,6-diiodo-4,5-dialkyl-phthalic acid dimethyl ester,para-diiodobenzene derivative crystal structure X-ray diffraction NMR

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Fabrication, characterization, in vitro drug release and glucose uptake activity of 14-deoxy,11, 12-didehydroandrographolide loaded polycaprolactone nanoparticles

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Asian Journal of Pharmaceutical Sciences 2017年第4期12卷 353-362页

作者： Nagalakshmi Kamaraj Pooja Yashwanthi Rajaguru Praveen kumar Issac Sujatha Sundaresan department of Biotechnology School of Bioengineering SRM University

Biodegradable polymer based novel drug delivery systems brought a considerable attention in enhancing the therapeutic efficacy and bioavailability of various drugs. 14-deoxy 11, 12-didehydro andrographolide(poorly water soluble compound) loaded polycaprolactone(nanoDDA) was synthesized using the solvent evaporation technique. Nano-DDA was characterized by scanning electron microscopy(SEM) and dynamic light scattering(DLS) studies. Fourier Transform InfraRed Spectroscopy(FTIR) was used to investigate the structural interaction between the drug and the polymer. Functional characterization of the formulation was determined using drug content, cellular uptake and in vitro drug release. 2-deoxy-D-[1-~3H] glucose uptake assay was carried out to assess the antidiabetic potential of nano-DDA in L6 *** nano-DDA displayed spherical shape with a smooth surface(252.898 nm diameter), zeta potential, encapsulation and loading efficiencies of -38.9 mV, 91.98 ± 0.13% and 15.09 ± 0.18% respectively. No structural alteration between the drug and the polymer was evidenced(FTIR analysis). Confocal microscopy studies with rhodamine 123 loaded polycaprolactone nanoparticles(Rh123-PCL NPs) revealed the internalization of Rh123-PCL NPs in a time dependent manner in L6 myoblasts. A dose dependent increase in glucose uptake was observed for nano-DDA with a maximal uptake of 108.54 ± 1.42% at 100 nM on L6 myotubes, thereby proving its anti-diabetic efficacy. A biphasic pattern of in vitro drug release demonstrated an initial burst release at 24 h followed by a sustained release for up to 11 days. To conclude,our results revealed that nano-DDA formulation can be a potent candidate for antidiabetic drug delivery.

关键词： Nanoencapsulation Polycaprolactone 14-deoxy 11,12-didehydro andrographolide Glucose uptake In vitro drug release Cellular uptake

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Crystal Structure,Photoluminescence and Theoretical Studies of Diethyl 4,5-di(thienyl)-3,6-bis(trimethylsilyl)phthalate

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Chinese Journal of Structural Chemistry 2013年第10期32卷 1560-1566页

作者：唐建可牛心蕙蒋丽丽曲红梅 Key Laboratory of systems bioengineering Ministry of EducationTianjin Key Laboratory of Biological and Pharmaceutical EngineeringDepartment of Pharmaceutical Engineering School of Chemical Engineering and TechnologyTianjin University

The crystal structure of the title compound, diethyl 4,5-di（thienyl）-3,6-bis（trime- thylsilyl）phthalate （C26H3404S2Si2, Mr = 530.83）, has been determined by single-crystal X-ray diffraction. The crystal belongs to the orthorhombic system, space group Pccn with a = 43.008（5）, b = 10.9000（12）, c = 11.9357（14） A, V= 5595.3（11） A3, Z = 8, F（000） = 2256, Dc= 1.260 mg/m3, p = 0.305 mm-1, T = 113（2） K, S = 1.090, R = 0.0413 and wR = 0.0969 for 5952 observed reflections with 1 〉 2o（/）. The benzene ring system is planar and makes dihedral angles of 63.7（2） and 72.5（4） with the two thienyl rings A （C（23）-C（26）, S（2）） and B （C（19）-C（22）, S（1））, respectively. The UV-vis absorption and fluorescence of the title compound were discussed. The molecular structure of the title compound has been optimized using DFT method at the B3LYP/6-31G（d） level. The computational results showed that the optimized geometer parameters are consistent well with the experiment data. The vertical ionization potential, vertical electron affinity and frontier orbitals were also discussed.

关键词： crystal structure benzene derivatives orthorhombic system,photoluminescence B3LYP/6-31G(d)

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Synthesis and Properties of Novel Fluorescence Probe Based on 1,8-Naphthalimide for Detection of Hydrogen Sulfide

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Chemical Research in Chinese Universities 2019年第1期35卷 5-11页

作者： MA Yunxia ZHANG Jie QU Hongmei Key Laboratory of systems bioengineering Ministry of EducationDepartment of Pharmaceutical Engineering School of Chemical Engineering and TechnologyTianjin UniversityTianjin 300072P.R.China

Two fluorescence-enhanced probes,4-(2,4-dinitrophenoxy)-N-(2-hydroxyethyl)-1,8-naphthalimide(NTE-1)and 4-(2,4-dinitrophenoxy)-N-[4-(2,4-dinitrophenoxy)phenyl]-1,8-naphthalimide(NTE-2),have been designed and synthesized for detection of H2S.4-Hydroxy-1,8-naphthalimide as fluorophore in combination with 2,4-dinitrophenyl ether as H2S response site constructed the fluorescence *** consequences showed that both NTE-1 and NTE-2 displayed large red-shift(excess 100nm)in absorption spectra and more than 30-fold fluorescence enhancement in response to ***,the dual site probe,NTE-2,displayed wider linear range between fluorescence intensity and concentration of H2S(0-40μmol/L)compared with single site probe,which can be applied to quantita-tive detection of high concentration of *** photomduced electron transfer(PET)response mechanism of probe was further studied by analyzing the distributions of molecular ***,the probes have potential practical applications in the detection of H2S.

关键词： 2,4-Dinitrophenyl ether Dual site Gaussian Photoinduced electron transfer

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