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https://www.readbyqxmd.com/read/27905575/protoporphyrin-ix-modified-chitosan-g-oligo-nipaam-polymeric-micelles-from-physical-stabilization-to-permeability-characterization-in-vitro
#1
Inbar Schlachet, Alejandro Sosnik
Two main hurdles persist towards the more extensive bench-to-bed side translation of non-parenteral polymeric micelles. The first pertains to their thermodynamically-driven disassembly under uncontrolled dilution conditions in the biological milieu and upon interaction with biomacromolecules (e.g., proteins). The second is related to the relatively poor understanding of the pathways by which polymeric micelles improve the bioavailability of the payload by mucosal routes (e.g., intestinal). In this work, a chitosan-g-oligo(N-isopropylacrylamide) (CS-g-oligo(NiPAAm)) copolymer was modified with non-cytotoxic amounts of protoporphyrin IX (PP), a planar molecule of amphiphilic character that undergoes self-aggregation in water by forming π-π stacked supramolecular structures, to induce micellization under disfavored conditions and to serve as a fluorescent tracer for the measurement of the micelle permeability across a model of the intestinal epithelium in vitro...
December 1, 2016: Biomaterials Science
https://www.readbyqxmd.com/read/27873288/cardioprotective-effect-of-aloe-vera-biomacromolecules-conjugated-with-selenium-trace-element-on-myocardial-ischemia-reperfusion-injury-in-rats
#2
Yang Yang, Ming Yang, Fen Ai, Congxin Huang
The present study was undertaken to evaluate the cardioprotection potential and underlying molecular mechanism afforded by a selenium (Se) polysaccharide (Se-AVP) from Aloe vera in the ischemia-reperfusion (I/R) model of rats in vivo. Myocardial I/R injury was induced by occluding the left anterior descending coronary artery (LAD) for 30 min followed by 2-h continuous reperfusion. Pretreatment with Se-AVP (100, 200, and 400 mg/kg) attenuated myocardial damage, as evidenced by reduction of the infarct sizes, increase in serum and myocardial endogenous antioxidants (superoxide dismutase (SOD), glutathione peroxidase (GSH), and catalase (CAT)), and decrease in the malondialdehyde (MDA) level in the rats suffering I/R injury...
November 21, 2016: Biological Trace Element Research
https://www.readbyqxmd.com/read/27864764/fret-flim-for-visualizing-and-quantifying-protein-interactions-in-live-plant-cells
#3
Alejandra Freire Rios, Tatyana Radoeva, Bert De Rybel, Dolf Weijers, Jan Willem Borst
Proteins are the workhorses that control most biological processes in living cells. Although proteins can accomplish their functions independently, the vast majority of functions require proteins to interact with other proteins or biomacromolecules. Protein interactions can be investigated through biochemical assays such as co-immunoprecipitation (co-IP) or Western blot analysis, but such assays lack spatial information. Here we describe a well-developed imaging method, Förster resonance energy transfer (FRET) analyzed by fluorescence lifetime imaging microscopy (FLIM), that can be used to visualize protein interactions with both spatial and temporal resolution in live cells...
2017: Methods in Molecular Biology
https://www.readbyqxmd.com/read/27863136/biological-and-environmental-surface-interactions-of-nanomaterials-characterization-modeling-and-prediction
#4
REVIEW
Ran Chen, Jim E Riviere
The understanding of nano-bio interactions is deemed essential in the design, application, and safe handling of nanomaterials. Proper characterization of the intrinsic physicochemical properties, including their size, surface charge, shape, and functionalization, is needed to consider the fate or impact of nanomaterials in biological and environmental systems. The characterizations of their interactions with surrounding chemical species are often hindered by the complexity of biological or environmental systems, and the drastically different surface physicochemical properties among a large population of nanomaterials...
November 8, 2016: Wiley Interdisciplinary Reviews. Nanomedicine and Nanobiotechnology
https://www.readbyqxmd.com/read/27816460/cuprac-colorimetric-and-electroanalytical-methods-determining-antioxidant-activity-based-on-prevention-of-oxidative-dna-damage
#5
Seda Uzunboy, Sema Demirci Çekiç, Ece Eksin, Arzum Erdem, Reşat Apak
An unbalanced excess of oxygen/nitrogen species (ROS/RNS) can give oxidative hazard to DNA and other biomacromolecules under oxidative stress conditions. While the 'comet' assay for measuring DNA damage is neither specific nor practical, monitoring oxidative changes on individual DNA bases and other oxidation products needs highly specialized equipment and operators. Thus, we developed a modified CUPRAC (cupric ion reducing antioxidant capacity) colorimetric method to determine the average total damage on DNA produced by Fenton oxidation, taking advantage of the fact that the degradation products of DNA but not the original macromolecule is CUPRAC-responsive...
November 2, 2016: Analytical Biochemistry
https://www.readbyqxmd.com/read/27810769/effects-of-gene-carrier-polyethyleneimines-on-the-structure-and-binding-capability-of-bovine-serum-albumin
#6
Zhiyong Guo, Zhijie Kong, Yanshan Wei, Hua Li, Yajing Wang, Aimin Huang, Lin Ma
Polyethyleneimine (PEI), one of the most effective non-viral gene carriers, is also cytotoxic, however the molecular basis is poorly understood. Little is known about the effects of PEI on the structure and functions of the biomacromolecules. In this work, fluorescence, UV-vis absorption, circular dichroism (CD) spectroscopy and zeta-potential measurement were conducted to reveal the interaction between PEIs (average molecular weight 25, 10 and 1.8kDa) and bovine serum albumin (BSA), and to evaluate the effects on the conformation of BSA as long as its binding capability to the model compounds, 8-anilino-1-naphthalenesulfonic acid (ANS) and quercetin...
October 17, 2016: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
https://www.readbyqxmd.com/read/27806190/dendrimeric-guanidinoneomycin-for-cellular-delivery-of-bio-macromolecules
#7
Aurora Sganappa, Ezequiel Wexselblatt, Maria Cristina Bellucci, Jeffrey D Esko, Gabriella Tedeschi, Yitzhak Tor, Alessandro Volonterio
We present the synthesis of polymeric amino- and guanidinoglycosides prepared by tethering neomycin and guanidinoneomycin to PAMAM dendrimers of generations 2 and 4. The ability of these conjugates to promote cellular uptake of high-molecular-weight cargo is discussed, together with their cytotoxicity and mechanisms of entry. We demonstrate that the presence of multiple guanidinoneomycin carriers on the PAMAM surface plays an important role in promoting cellular uptake of the dendrimers, maintaining the heparan sulfate specificity and negligible cytotoxicity typical of monomeric guanidinoglycoside molecular transporters...
November 2, 2016: Chembiochem: a European Journal of Chemical Biology
https://www.readbyqxmd.com/read/27802720/the-rheo-raman-microscope-simultaneous-chemical-conformational-mechanical-and-microstructural-measures-of-soft-materials
#8
Anthony P Kotula, Matthew W Meyer, Francesca De Vito, Jan Plog, Angela R Hight Walker, Kalman B Migler
The design and performance of an instrument capable of simultaneous Raman spectroscopy, rheology, and optical microscopy are described. The instrument couples a Raman spectrometer and optical microscope to a rotational rheometer through an optically transparent base, and the resulting simultaneous measurements are particularly advantageous in situations where flow properties vary due to either chemical or conformational changes in molecular structure, such as in crystallization, melting, gelation, or curing processes...
October 2016: Review of Scientific Instruments
https://www.readbyqxmd.com/read/27797530/theory-and-simulation-of-cholesteric-film-formation-flows-of-dilute-collagen-solutions
#9
O F Aguilar Gutierrez, Alejandro D Rey
Dilute isotropic collagen solutions are usually flow processed into monodomain chiral nematic thin films for obtaining highly ordered materials by a multistep process that starts with complex inhomogeneous flow kinematics. Here we present rigorous theory and simulation of the initial precursors during flow steps in cholesteric collagen film formation. We first extract the molecular shape parameter and rotational diffusivity from previously reported simple shear data of dilute collagen solutions, where the former leads the reactive parameter (tumbling function) which determines the net effect of vorticity and strain rate on the average orientation and where the latter establishes the intensity of strain required for flow-birefringence, both crucial quantities for controlled film formation flow...
October 31, 2016: Langmuir: the ACS Journal of Surfaces and Colloids
https://www.readbyqxmd.com/read/27773338/biomacromolecules-based-core-shell-architecture-toward-biomedical-applications
#10
Wei Cui, Anhe Wang, Jie Zhao, Junbai Li
Polyelectrolyte multilayer capsules have become a novel and promising class of hybrid materials with great potential since they can be applied in various areas, such as pharmaceutical sciences, biotechnology, and biomedicine. The concept of using such carriers for biology application is diagnosis and treatment of diseases for convenience, safety and specific targeting. Therefore, the development of biocompatible, biodegradable and specific characteristic nanostructure material is highly desirable. Much effort has been devoted to exploring innovative and effective techniques to fabricate such materials...
October 6, 2016: Advances in Colloid and Interface Science
https://www.readbyqxmd.com/read/27768314/monomer-oligomer-quasi-racemic-protein-crystallography
#11
Shuai Gao, Man Pan, Yong Zheng, Yichao Huang, Qingyun Zheng, Demeng Sun, Lining Lu, Xiaodan Tan, Xianglong Tan, Huan Lan, Jiaxing Wang, Tian Wang, Jiawei Wang, Lei Liu
Racemic or quasi-racemic crystallography recently emerges as a useful technology for solution of the crystal structures of biomacromolecules. It remains unclear to what extent the biomacromolecules of opposite handedness can differ from each other in racemic or quasi-racemic crystallography. Here we report a finding that monomeric d-ubiquitin (Ub) has propensity to cocrystallize with different dimers, trimers, and even a tetramer of l-Ub. In these cocrystals the unconnected monomeric d-Ubs can self-assemble to form pseudomirror images of different oligomers of l-Ub...
October 21, 2016: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/27759491/dna-binding-study-of-anticancer-drug-cytarabine-by-spectroscopic-and-molecular-docking-techniques
#12
Nahid Shahabadi, Monireh Falsafi, Maryam Maghsudi
The interaction of anticancer drug cytarabine with calf thymus DNA (CT-DNA) was investigated in vitro under simulated physiological conditions by multispectroscopic techniques and molecular modeling study. The fluorescence spectroscopy and UV absorption spectroscopy indicated drug interacted with CT-DNA in a groove-binding mode, while the binding constant of UV-vis and the number of binding sites were 4.0 ± 0.2 × 10(4) L mol(-1) and 1.39, respectively. The fluorimetric studies showed that the reaction between the drugs with CT-DNA is exothermic...
October 19, 2016: Nucleosides, Nucleotides & Nucleic Acids
https://www.readbyqxmd.com/read/27750002/superior-performance-of-polyurethane-based-on-natural-melanin-nanoparticles
#13
Yang Wang, Ting Li, Xuefei Wang, Piming Ma, Huiyu Bai, Weifu Dong, Yi Xie, Mingqing Chen
Melanin, a kind of well-known multifunctional biomacromolecules that are widely available in large quantities from a variety of natural sources. In this work, Polyurethane (PU) /melanin nanocomposites with enhanced tensile strength and toughness were successfully fabricated via in situ polymerization. It was found that the tensile strength (σ), elongation-at-break (εmax) and work to fracture (W) were increased from 5.6 MPa, 770% and 33 MJ/m3 for PU to 51.5 MPa, 1880% and 413 MJ/m3 for PU/melanin (2 wt %) nanocomposite, respectively...
October 17, 2016: Biomacromolecules
https://www.readbyqxmd.com/read/27748399/vectorization-of-biomacromolecules-into-cells-using-extracellular-vesicles-with-enhanced-internalization-induced-by-macropinocytosis
#14
Ikuhiko Nakase, Kosuke Noguchi, Ikuo Fujii, Shiroh Futaki
Extracellular vesicles (EVs, exosomes) are approximately 30- to 200-nm-long vesicles that have received increased attention due to their role in cell-to-cell communication. Although EVs are highly anticipated to be a next-generation intracellular delivery tool because of their pharmaceutical advantages, including non-immunogenicity, their cellular uptake efficacy is low because of the repulsion of EVs and negatively charged cell membranes and size limitations in endocytosis. Here, we demonstrate a methodology for achieving enhanced cellular EV uptake using arginine-rich cell-penetrating peptides (CPPs) to induce active macropinocytosis...
October 17, 2016: Scientific Reports
https://www.readbyqxmd.com/read/27740660/fluorescent-glycoprobes-a-sweet-addition-for-improved-sensing
#15
Xiao-Peng He, Yi Zang, Tony D James, Jia Li, Guo-Rong Chen, Juan Xie
The development of small-molecule fluorescent probes for the detection of ions and biomacromolecules and for cellular and in vivo imaging has been a very active research area. Nevertheless, many problems exist for traditional probes including their poor water solubility, toxicity and the inability to target specific tissues. Because of the enhanced water solubility, biocompatibility and targeting ability for specific cells, there has been an emerging movement to use carbohydrates as either the backbone or as a warhead to decorate conventional fluorescent probes, producing "glycoprobes" with enhanced properties...
October 14, 2016: Chemical Communications: Chem Comm
https://www.readbyqxmd.com/read/27725629/fabrication-of-fibrillosomes-from-droplets-stabilized-by-protein-nanofibrils-at-all-aqueous-interfaces
#16
Yang Song, Ulyana Shimanovich, Thomas C T Michaels, Qingming Ma, Jingmei Li, Tuomas P J Knowles, Ho Cheung Shum
All-aqueous emulsions exploit spontaneous liquid-liquid separation and due to their water-based nature are particular advantageous for the biocompatible storage and processing of biomacromolecules. However, the ultralow interfacial tensions characteristic of all-aqueous interfaces represent an inherent limitation to the use of thermally adsorbed particles to achieve emulsion stability. Here, we use protein nanofibrils to generate colloidosome-like two-dimensional crosslinked networks of nanostructures templated by all-aqueous emulsions, which we term fibrillosomes...
October 11, 2016: Nature Communications
https://www.readbyqxmd.com/read/27722717/-light-up-protein-protein-interaction-through-bioorthogonal-incorporation-of-a-turn-on-fluorescent-probe-into-%C3%AE-lactamase
#17
Rui Hu, Hong-Kin Yap, Yik-Hong Fung, Yong Wang, Wing-Lam Cheong, Lok-Yan So, Chui-Shan Tsang, Lawrence Yoon Suk Lee, Warrick Ken Cheung Lo, Jian Yuan, Ning Sun, Yun-Chung Leung, Guoqiang Yang, Kwok-Yin Wong
Fluorescent labeling of biomacromolecules to 'light up' biological events through non-invasive methods is of great importance, but is still challenging in terms of fluorophore properties and the labeling methods used. Herein, we designed and synthesized a biocompatible and conformation sensitive tetraphenylethene derivative EPB with aggregation induced emission (AIE) properties. By introducing EPB into TEM-1 β-lactamase (TEM-1 Bla) through a two-step approach, a conformation-dependent fluorescent sensor EPB104-Bla was genetically engineered, which was applied to monitor the protein-protein interaction (PPI) with β-lactamase inhibitor protein (BLIP)...
October 4, 2016: Molecular BioSystems
https://www.readbyqxmd.com/read/27722335/dipeptide-concave-nanospheres-based-on-interfacially-controlled-self-assembly-from-crescent-to-solid
#18
Juan Wang, Guizhi Shen, Kai Ma, Tifeng Jiao, Kai Liu, Xuehai Yan
Concave nanospheres based on the self-assembly of simple dipeptides not only provide alternatives for modeling the interactions between biomacromolecules, but also present a range of applications for purification and separation, and delivery of active species. The kinetic control of the peptide assembly provides a unique opportunity to build functional and dynamic nanomaterials, such as concave nanospheres. In this work, we report dipeptide-based concave nanospheres with structures from crescent-like to solid interior by interfacially controlled self-assembly in combination with covalent formation of building blocks, driven by synergistic thermodynamic and kinetic control...
November 16, 2016: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/27710927/biomacromolecule-immobilization-grafting-of-fish-scale-collagen-peptides-onto-aminolyzed-p-3hb-co-4hb-scaffolds-as-a-potential-wound-dressing
#19
S Vigneswari, V Murugaiyah, G Kaur, H P S Abdul Khalil, A A Amirul
Polyhydroxyalkanoate (PHA) is a microbial polymer that has been at the forefront of many attempts at tissue engineering. However, the surface of poly(3-hydroxybutyrate-co-4-hydroxybutyrate) (P(3HB-co-4HB)) is hydrophobic with few recognition sites for cell attachment. Various concentrations of fish-scale collagen peptides (FSCPs) were incorporated into P(3HB-co-4HB) copolymer by aminolysis. Later, FSCPs were introduced onto the aminolyzed P(3HB-co-4HB) scaffolds. Introduction of the FSCP groups was verified using Fourier transform infrared spectroscopy and the ninhydrin method...
October 6, 2016: Biomedical Materials
https://www.readbyqxmd.com/read/27704088/fourier-transform-infrared-spectroscopy-on-external-perturbations-inducing-secondary-structure-changes-of-hemoglobin
#20
Rui Lu, Wen-Wei Li, Abraham Katzir, Yosef Raichlin, Boris Mizaikoff, Han-Qing Yu
The secondary structure of proteins and their conformation are intimately related to their biological functions. In this study, heat-induced changes in the secondary structure and conformation of hemoglobin were investigated via infrared attenuated total reflection (IR-ATR) spectroscopy. The secondary structure changes of hemoglobin were derived from IR-ATR spectra using second derivatives and curve fitting. Thereby, the thermal denaturation temperature ranges and the secondary structure changes with temperature were revealed...
October 17, 2016: Analyst
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