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Lei Wang, Kathryn A Stevens, Paul Haupt-Renaud, R Kenneth Marcus
A new, trilobal shaped capillary-channeled polymer fiber is under development to address the issues of poor A-term performance of the previous eight-channeled form. The trilobal geometry should provide better packing homogeneity due to the fewer potential orientations of the symmetric fiber geometry. Comparisons of separation efficiency and peak shape were made between the two fiber shapes through several dynamic parameters. Column hydrodynamics were investigated with two marker compounds, uracil and bovine serum albumin, with van Deemter plots of those two compounds revealing differences in the packing qualities between the different fiber shapes...
December 12, 2017: Journal of Separation Science
Jianmin Chen, Weiyue Huang, Ziyao Huang, Shiqi Liu, Yaling Ye, Qinglian Li, Meiping Huang
Dissolving microneedles (MNs) offered a simple, minimally invasive method for meloxicam (MX) delivery to the skin. However, the fabrication of dissolving MNs still faced some challenges, such as significant time consumption, loss of drug activity, and difficulty in regulating MN drug loading. To address these issues, we developed the tip-dissolving (TD) MNs. Several kinds of drugs were encapsulated successfully, and the quantity of MX ranged from 37.23 ± 8.40 to 332.53 ± 13.37 μg was precisely controlled...
December 7, 2017: AAPS PharmSciTech
Min Zheng, Nigel W Moriarty, Yanting Xu, Jeffrey R Reimers, Pavel V Afonine, Mark P Waller
Accurately refining biomacromolecules using a quantum-chemical method is challenging because the cost of a quantum-chemical calculation scales approximately as nm, where n is the number of atoms and m (≥3) is based on the quantum method of choice. This fundamental problem means that quantum-chemical calculations become intractable when the size of the system requires more computational resources than are available. In the development of the software package called Q|R, this issue is referred to as Q|R#1. A divide-and-conquer approach has been developed that fragments the atomic model into small manageable pieces in order to solve Q|R#1...
December 1, 2017: Acta Crystallographica. Section D, Structural Biology
Slađana Strmečki, Emil Paleček
Previously, it has been shown that proteins and some polysaccharides (PSs) catalyse hydrogen evolution, producing electrochemical signals on mercury electrodes. The catalytic hydrogen evolution reaction (CHER) of the above-mentioned biomacromolecules was studied by voltammetric and chronopotentiometric stripping (CPS) methods. To obtain more information about electrode processes involving CHER, here we used protein such as BSA, and chitosan as a PS; in addition, we investigated dextran as a control PS not involved in CHER...
November 29, 2017: Bioelectrochemistry
Nathaniel P Chongsiriwatana, Jennifer S Lin, Rinki Kapoor, Modi Wetzler, Jennifer A C Rea, Maruti K Didwania, Christopher H Contag, Annelise E Barron
Many organisms rely on antimicrobial peptides (AMPs) as a first line of defense against pathogens. In general, most AMPs are thought to kill bacteria by binding to and disrupting cell membranes. However, certain AMPs instead appear to inhibit biomacromolecule synthesis, while causing less membrane damage. Despite an unclear understanding of mechanism(s), there is considerable interest in mimicking AMPs with stable, synthetic molecules. Antimicrobial N-substituted glycine (peptoid) oligomers ("ampetoids") are structural, functional and mechanistic analogs of helical, cationic AMPs, which offer broad-spectrum antibacterial activity and better therapeutic potential than peptides...
December 1, 2017: Scientific Reports
Satoru Unzai
Researchers in the field of structural biology, especially X-ray crystallography and protein nuclear magnetic resonance, are interested in knowing as much as possible about the state of their target protein in solution. Not only is this knowledge relevant to studies of biological function, it also facilitates determination of a protein structure using homogeneous monodisperse protein samples. A researcher faced with a new protein to study will have many questions even after that protein has been purified. Analytical ultracentrifugation (AUC) can provide all of this information readily from a small sample in a non-destructive way, without the need for labeling, enabling structure determination experiments without any wasting time and material on uncharacterized samples...
November 29, 2017: Biophysical Reviews
T Gopinath, Sarah E D Nelson, Gianluigi Veglia
Magic angle spinning (MAS) solid-state NMR (ssNMR) spectroscopy is emerging as a unique method for the atomic resolution structure determination of native membrane proteins in lipid bilayers. Although 13C-detected ssNMR experiments continue to play a major role, recent technological developments have made it possible to carry out 1H-detected experiments, boosting both sensitivity and resolution. Here, we describe a new set of 1H-detected hybrid pulse sequences that combine through-bond and through-space correlation elements into single experiments, enabling the simultaneous detection of rigid and dynamic domains of membrane proteins...
December 2017: Journal of Magnetic Resonance
Lawrence P Fernando, Jamal S Lewis, Brian C Evans, Craig L Duvall, Benjamin G Keselowsky
Poly(lactic-co-glycolic acid) (PLGA) is widely used as a vehicle for delivery of pharmaceutically relevant payloads. PLGA is readily fabricated as a nano- or microparticle (MP) matrix to load both hydrophobic and hydrophilic small molecular drugs as well as biomacromolecules such as nucleic acids and proteins. However, targeting such payloads to the cell cytosol is often limited by MP entrapment and degradation within acidic endolysosomes. Poly(propylacrylic acid) (PPAA) is a polyelectrolyte polymer with membrane disruptive capability triggered at low pH...
November 22, 2017: Journal of Biomedical Materials Research. Part A
JiaFeng Huang, RiBang Wu, CuiLing Wu, Dan Liu, Jiang Zhang, BinQiang Liao, Ming Lei, Xiao Xiao, ChangBei Ma, HaiLun He
The C-terminal domains of proteases play crucial roles in hydrolysis, substrate adsorption and targeted binding. Identifying and characterizing interactions between C-terminal domains and biomacromolecules can help to examine the diversity as well as the substrate-binding ability of C-terminal domains and to explore novel functions. The bacterial pre-peptidase C-terminal (PPC) domain is a typical C-terminal domain normally found at the C-terminus of bacterial secreted proteases. In this work, we successfully demonstrated that 8-anilinonaphthalene-1-sulfonic acid (ANS) could be used to rapidly determine the interactions between this C-terminal domain and biomacromolecules...
November 18, 2017: Journal of Biotechnology
Imtiyaz Ahmad Bhat, Waseem Feeroze Bhat, Mohd Akram, Kabir-Ud-Din
Herein, we have examined the interaction of oxy-diester novel twin tailed (gemini) surfactant, 2,2(')-[(oxybis(ethane-1,2-diyl))bis(oxy)]bis(N-hexadecyl-N,Ndimethyl-2-oxoethanaminium) dichloride (C16-E2O-C16) with hen egg white lysozyme (HEWL), utilizing a spectroscopic and molecular docking techniques. Steady-state fluorescence infers ground state C16-E2O-C16-HEWL complex formation. Other spectroscopic results validated the conformational, structural and micro-environmental changes in HEWL upon interaction with C16-E2O-C16...
November 14, 2017: International Journal of Biological Macromolecules
Samuel F Cousin, Pavel Kadeřávek, Nicolas Bolik-Coulon, Fabien Ferrage
Many of the functions of biomacromolecules can be rationalized by the characterization of their conformational energy landscapes: the structures of the dominant states, transitions between states and motions within states. Nuclear magnetic resonance (NMR) spectroscopy is the technique of choice to study internal motions in proteins. The determination of motions on picosecond to nanosecond timescales requires the measurement of nuclear spin relaxation rates at multiple magnetic fields. High sensitivity and resolution are obtained only at high magnetic fields, so that, until recently, site-specific relaxation rates in biomolecules were only measured over a narrow range of high magnetic fields...
2018: Methods in Molecular Biology
Caroline I Biggs, Trisha L Bailey, Ben Graham, Christopher Stubbs, Alice Fayter, Matthew I Gibson
Antifreeze proteins from polar fish species are remarkable biomacromolecules which prevent the growth of ice crystals. Ice crystal growth is a major problem in cell/tissue cryopreservation for transplantation, transfusion and basic biomedical research, as well as technological applications such as icing of aircraft wings. This review will introduce the rapidly emerging field of synthetic macromolecular (polymer) mimics of antifreeze proteins. Particular focus is placed on designing polymers which have no structural similarities to antifreeze proteins but reproduce the same macroscopic properties, potentially by different molecular-level mechanisms...
November 16, 2017: Nature Communications
Miao Chen, Wen Luo, Zhimin Zhang, Ranhao Wang, Yuqiu Zhu, Hua Yang, Xiaoqing Chen
Surface-enhanced Raman scattering (SERS) based biosensing in biological fluids is constrained by nonspecific macromolecules adsorptions and disposable property of the SERS substrate. Here, novel multi-Au nanoparticles-embedded mesoporous silica microspheres (AuNPs/mSiO2) was prepared using a one-pot method, which served as reliable substrates for SERS enhancement associated with salient features of self-filtering ability and reusability. The fabrication and physical characterization of AuNPs/mSiO2 microspheres were discussed, and SERS activity of this novel substrates was investigated by using 4-mercaptobenzoic acid (4-MBA) as Raman probe...
November 15, 2017: ACS Applied Materials & Interfaces
Xuewei Liu, Danfeng Shi, Shuangyan Zhou, Hongli Liu, Huanxiang Liu, Xiaojun Yao
Molecular dynamics (MD) simulations can provide not only plentiful dynamical structural information on biomacromolecules but also a wealth of energetic information about protein and ligand interactions. Such information is very important to understanding the structure-function relationship of the target and the essence of protein-ligand interactions and to guiding the drug discovery and design process. Thus, MD simulations have been applied widely and successfully in each step of modern drug discovery. Areas covered: In this review, the authors review the applications of MD simulations in novel drug discovery, including the pathogenic mechanisms of amyloidosis diseases, virtual screening and the interaction mechanisms between drugs and targets...
November 15, 2017: Expert Opinion on Drug Discovery
Patrik Stenström, Erik Hjorth, Yuning Zhang, Oliver C J Andrén, Simon Guette-Marquet, Marianne Schultzberg, Michael Malkoch
Amine functional polymers, especially cationically charged, are interesting biomacromolecules for several reasons, including easy cell membrane entrance, their ability to escape endosomes through the proton sponge effect, spontaneous complexation and delivery of drugs and siRNA, and simple functionalization in aqueous solutions. Dendrimers, a subclass of precision polymers, are monodisperse and exhibit a large and exact number of peripheral end groups in relation to their size and have shown promise in drug delivery, biomedical imaging and as antiviral agents...
November 22, 2017: Biomacromolecules
Kensuke Kurihara, Muneyuki Matsuo, Takumi Yamaguchi, Sota Sato
BACKGROUND: To imitate the essence of living systems via synthetic chemistry approaches has been attempted. With the progress in supramolecular chemistry, it has become possible to synthesize molecules of a size and complexity close to those of biomacromolecules. Recently, the combination of precisely designed supramolecules with biomolecules has generated structural platforms for designing and creating unique molecular systems. Bridging between synthetic chemistry and biomolecular science is also developing methodologies for the creation of artificial cellular systems...
November 9, 2017: Biochimica et Biophysica Acta
Wei-Ting Chen, Shao-Sian Li, Jinn P Chu, Kuei Chih Feng, Jem-Kun Chen
In this study, a photoresist template with well-defined contact hole array was fabricated, to which radio frequency magnetron sputtering process was then applied to deposit an alloyed Zr55Cu30Al10Ni5 target, and finally resulted in ordered metallic glass nanotube (MGNT) arrays after removal of the photoresist template. The thickness of the MGNT walls increased from 98 to 126nm upon increasing the deposition time from 225 to 675s. The wall thickness of the MGNT arrays also increased while the dimensions of MGNT reduced under the same deposition condition...
October 18, 2017: Biosensors & Bioelectronics
Weining Wan, Honglin Huang, Jitao Lv, Ruixia Han, Shuzhen Zhang
The uptake, translocation and biotransformation of organophosphate esters (OPEs) by wheat (Triticum aestivum L.) were investigated by a hydroponic experiment. The results demonstrated that OPEs with higher hydrophobicity were more easily taken up by roots, and OPEs with lower hydrophobicity were more liable to be translocated acropetally. A total of 43 metabolites including dealkylated, oxidatively dechlorinated, hydroxylated, methoxylated, and glutathione- and glucuronide- conjugated products were detected derived from eight OPEs, with di-esters formed by direct dealkylation from the parent tri-esters as the major products, followed with hydroxylated tri-esters...
November 10, 2017: Environmental Science & Technology
Li-Wei Chang, Tyler K Lytle, Mithun Radhakrishna, Jason J Madinya, Jon Vélez, Charles E Sing, Sarah L Perry
Biomacromolecules rely on the precise placement of monomers to encode information for structure, function, and physiology. Efforts to emulate this complexity via the synthetic control of chemical sequence in polymers are finding success; however, there is little understanding of how to translate monomer sequence to physical material properties. Here we establish design rules for implementing this sequence-control in materials known as complex coacervates. These materials are formed by the associative phase separation of oppositely charged polyelectrolytes into polyelectrolyte dense (coacervate) and polyelectrolyte dilute (supernatant) phases...
November 2, 2017: Nature Communications
Jin Zhang, Ting Zheng, Emine Alarçin, Batzaya Byambaa, Xiaofei Guan, Jianxun Ding, Yu Shrike Zhang, Zhongming Li
Stimuli-responsive porous polymer materials have promising biomedical application due to their ability to trap and release biomacromolecules. In this work, a class of highly porous electrospun fibers is designed using polylactide as the polymer matrix and poly(ethylene oxide) as a porogen. Carbon nanotubes (CNTs) with different concentrations are further impregnated onto the fibers to achieve self-sealing functionality induced by photothermal conversion upon light irradiation. The fibers with 0.4 mg mL(-1) of CNTs exhibit the optimum encapsulation efficiency of model biomacromolecules such as dextran, bovine serum albumin, and nucleic acids, although their photothermal conversion ability is slightly lower than the fibers with 0...
November 2, 2017: Small
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