检索结果-南通市图书馆

Elucidation of the early infection machinery of hepatitis B virus by using bio-nanocapsule

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2016年第38期22卷 8489-8496页

作者： Qiushi Liu Masaharu Somiya Shun'ichi Kuroda Department of Biomolecular Science and Reaction The Institute of Scientific and Industrial ResearchOsaka University

Currently, hepatitis B virus(HBV), upon attaching to human hepatocytes, is considered to interact first with heparan sulfate proteoglycan(HSPG) via an antigenic loop of HBV envelope S protein. Then, it is promptly transferred to the sodium taurocholate cotransporting polypeptide(NTCP) via the myristoylated N-terminal sequence of pre-S1 region(from Gly-2 to Gly-48, HBV genotype D), and it finally enters the cell by endocytosis. However, it is not clear how HSPG passes HBV to NTCP and how NTCP contributes to the cellular entry of HBV. Owing to the poor availability and the difficulty of manipulations, including fluorophore encapsulation, it has been nearly impossible to perform biochemical and cytochemical analyses using a substantial amount of HBV. A bio-nanocapsule(BNC), which is a hollow nanoparticle consisting of HBV envelope L protein, was efficiently synthesized in Saccharomyces cerevisiae. Since BNC could encapsulate payloads(drugs, genes, proteins) and specifically enter human hepatic cells utilizing HBV-derived infection machinery, it could be used as a model of HBV infection to elucidate the early infection machinery. Recently, it was demonstrated that the N-terminal sequence of pre-S1 region(from Asn-9 to Gly-24) possesses low p H-dependent fusogenic activity, which might play a crucial role in the endosomal escape of BNC payloads and in the uncoating process of HBV. In this minireview, we describe a model in which each domain of the HBV L protein contributes to attachment onto human hepatic cells through HSPG, initiation of endocytosis, interaction with NTCP in endosomes, and consequent provocation of membrane fusion followed by endosomal escape.

关键词： Bio-nanocapsule endosomal escape Hepatitis B virus Heparan sulfate proteoglycan Sodium taurocholate cotransporting polypeptide

Stability analysis of drugdynamics model: A mat hematical approach

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Biomathematics 2019年第4期12卷 153-184页

作者： Koyel Chakravarty D.C.Dalal Department of Mathematics Indian Institute of Technology Guwahati Guwahati 781039 India Faculty of Science and Technology ICFAI University TripuraTripura 799210India

In this paper, a mathematical model of drug release from polymeric matrix and consequent intracellular drug transport is proposed and analyzed. Modeling of drug release is done through solubilization dynamics of drug particles, diffusion of the solubilized drug through the polymeric matrix in addition to reversible dissociation/recrystallization process. The interaction between drug-receptor, drug-plasma proteins along with other intracellular endosomal events is modeled. This leads to a mixed system of partial and ordinary differential equations with associated pertinent set of initial and boundary conditions. Furthermore, besides the stability of the proposed model, several sub-models are also studied for their stability criteria. Prominence is provided to the reduced model system having requisite relevance to the original system where quasi steady state approximation (QSSA) theory is utilized. For the model to be potent enough to generate appropriate predictive results for drug delivery, the stability properties of equilibrium in the mathematical model are analyzed both analytically and numerically. Numerical simulation in the embodiment of graphical representations speaks about various vital characteristics of the underlying physical phenomena along with the importance and sensitized impact of the model parameters controlling significant biological functions. Probed new therapies and clinical procedures could be assessed considering the present mathematical model and its analysis as the basis framework in order to effectively enhance therapeutic efficacy and improved patient compliance. The present study confirms the necessity of stability analysis study so that advocated mathematical model can effectively complement the real physiological behavior of pharmacokinetics.

关键词： Mathematical model drug polymeric matrix endosomal events quasi steady state approximation (QSSA) stability

Synthesis, Biophysical Characterization and <i>in Vitro</i>Transfection Activity of Novel Bivalent Amine Cationic Lipids in the Absence of Dioleoylphosphatidylethanolamine (DOPE)

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Pharmacology & Pharmacy 2014年第11期5卷 1015-1028页

作者： Addai-Mensah Donkor Micheal Spelios Michalakis Savva Division of Pharmaceutical Sciences Arnold & Marie Schwartz College of Pharmacy and Health Sciences Long Island University New York USA Faculty of Applied Sciences Department of Applied Chemistry and Biochemistry University for Development Studies Navrongo Campus Upper East Region Ghana

In this paper, a novel series of bis [(aminoethyl)]-amine cationic lipid derivatives have been synthesized and identified to purity by NMR and Elemental analysis. B16-F0 cells were transfected with cationic lipid/pEGFP-N1 and cationic lipid/ß-gal lipoplexes complexed at +/- charge ratios of 1:1, 2:1, and 4:1. Dimyristoyl derivative showed highest activity at charge ratio 2:1 and both dimyristoyl and dioleoyl derivatives showed similar ß-gal activity at charge ratios 4:1. In 40 mM tris buffer pH 7.2 the dioleoyl derivative was able to fully complex with and retard pDNA at charge ratios above 2:1. None of the other lipid derivatives, dilauroyl, dimyristoyl, dipalmitoyl and distearoyl were able to fully neutralize the plasmid DNA at charge ratios similar to those used in the transfection experiment. The gel-to-liquid phase transition temperatures for dimyristoyl, dipalmitoyl and distearoyl were determined by a fluorescence anisotropy method to be 27.5°C, 32.5°C and 39°C, respectively. A gel-to-liquid crystalline phase transition temperature below 37°C, appears to be the crucial property that cationic lipids have to possess in order to mediate high levels of in vitro transfection activity in the absence of other helper lipids.

关键词： Gene Delivery Cationic Lipid Acyl Chain Fluidity Elasticity Lipoplex Transfection Non-Viral Vector DOPE endosomal Release TNS

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

主旨报告

神经药理学报 2019年第2期9卷 1-7页

PL-1 Presynaptic endosomal Cathepsin D Regulates the Biogenesis of GABAergic Synaptic Vesicles DUAN Shu-min Zhejiang University School of Medicine,Hangzhou,310058,China Dr. Shumin Duan is a professor at Zhejiang University School of Medicine,China. He got his Ph. D. from Kyushu University in Japan in 1991 and received a postdoctoral training at University of Hawaii and University of California at San Francisco during 1997-1999. His research interests include the function and the mechanisms of neuronglia interactions in health and disease and neural circuit mechanisms of brain functions. He is an academician of Chinese Academy of Sciences and a member of the Academy of Sciences for the Developing World (TWAS). He is the president of Chinese Society for Neuroscience and a council member of International Brain Research Organization. He serves as the Editor-in-Chief of Neuroscience Bulletin and an editorial board member in several international neuroscience journals.

关键词： Presynaptic endosomal Cathepsin Biogenesis