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Modification of Cellulose Nanofibrils with Luminescent Carbon Dots

Publication year: 2014
Authors: Junkka K. 1, Guo J. 1, Filpponen I. 1, Lainen J. 1, Rojas O.J. 1,2
Published in: Biomacromolecules, 2014, Vol. 15 (3), p. 876–881
Films and hydrogels consisting of cellulose nanofibrils (CNF) were modified by covalent EDC/NHS coupling of luminescent, water-dispersible carbon dots (CDs). [...]

Effects of Composition of Oligo(ethylene glycol)-Based Mixed Monolayers on Peptide Grafting and Human Immunoglobulin Detection

Publication year: 2014
Authors: Islam N. †, Gurgel P.V. †, Rojas O.J. †‡, Carbonell R.G. †§
Published in: Journal of Physical Chemistry, 2014, Vol. 118 (10), p. 5361–5373
Alkanethiols carrying ethylene glycol units (EGn, n = 3 or 6) with amine termini (EG3NH2 or EG6NH2) were coadsorbed with a “diluent”, hydroxyl-terminated alkanethiol (EG3OH), to form mixed self-assembled monolayers (SAMs). The mixed SAMs were characterized, and hexameric peptide ligand His-Trp-Arg-Gly-Trp-Val (HWRGWV), which shows affinity binding toward the Fc (constant fragment) of human immunoglobulin (IgG), was grafted onto different dilutions of EG6NH2–EG3OH mixed SAMs for preparation of IgG detection surfaces. [...]

The effect of coatings on the performance of the microelectrode arrays

Publication year: 2014
Authors: Sivasubramaniapandian Manoj
Published in: Master's Thesis
Microelectrode arrays (MEAs) are pretreated with suitable surface molecules prior to culturing of cells, since the properties of the substrate have a decisive effect on the adhesion, migration, differentiation, and the growth of the cells. The purpose of this thesis is to study a few of these coating materials, and to evaluate their impact on the performance of the MEA. [...]

Triggering Protein Adsorption on Tailored Cationic Cellulose Surfaces

Publication year: 2014
Authors: Mohan T. 1, Niegelhell K. 4, Pinto Zarth C.S. 2, Kargl R. 3, Köstler S. 5, Ribitsch V. 1, Heinze T. 2, Spirk S. 1,4, Stana-Kleinschek K. 3
Published in: Biomacromolecules, 2014, Vol. 15 (11), p. 3931–3941
The equipment of cellulose ultrathin films with BSA (bovine serum albumin) via cationization of the surface by tailor-made cationic celluloses is described. In this way, matrices for controlled protein deposition are created, whereas the extent of protein affinity to these surfaces is controlled by the charge density and solubility of the tailored cationic cellulose derivative. [...]

An impedimetric study of DNA hybridization on paper-supported inkjet-printed gold electrodes

Publication year: 2014
Authors: Ihalainen P. 1, Pettersson F. 2, Pesonen M. 2, Viitala T. 3, Määttänen A.1, Österbacka R. 2, Peltonen J. 1
Published in: Nanotechnology, 2014, Vol. 25, Issue 9
In this study, two different supramolecular recognition architectures for impedimetric detection of DNA hybridization have been formed on disposable paper-supported inkjet-printed gold electrodes. The gold electrodes were fabricated using a gold nanoparticle based ink. The first recognition architecture consists of subsequent layers of biotinylated self-assembly monolayer (SAM), streptavidin and biotinylated DNA probe. [...]

A universal molecular translator for non-nucleic acid targets that enables dynamic DNA assemblies and logic operations

Publication year: 2014
Authors: Tang W., Hu S., Wang H., Zhao Y., Li N., Liu F.*
Published in: Chemical Communications, 2014, Vol. 50, Issue 92, p. 14352-14355
A universal molecular translator based on the target-triggered DNA strand displacement was developed, which was able to convert various kinds of non-nucleic acid targets into a unique output DNA. [...]

Self-assembly of flagellin on Au(111) surfaces

Publication year: 2014
Authors: González Orive A. 1, Pissinis D.E. 2, Diaz C. 2, Miñán A. 2, Benítez G.A. 2, Rubert A. 2, Daza Millone A. 2, Rumbo M. 3, Hernández Creus A. 1, Salvarezza R.C. 2, Schilardi P.L. 4
Published in: Journal of Colloid and Interface Science, Vol. 433 (2014), p. 86–93
The adsorption of flagellin monomers from Pseudomonas fluorescens on Au(111) has been studied by Atomic Force Microscopy (AFM), Scanning Tunneling Microscopy (STM), X-ray Photoelectron Spectroscopy (XPS), Surface Plasmon Resonance (SPR), and electrochemical techniques. [...]

Dynamic and equilibrium performance of sensors based on short peptide ligands for affinity adsorption of human IgG using surface plasmon resonance

Publication year: 2014
Authors: Islam N. 1, Shen F. 1, Gurgel P.V. 1, Rojas O.J. 2, Carbonell R.G. 3
Published in: Biosensors and Bioelectronics, Vol. 58, 2014, p. 380-387
This paper characterizes the potential of novel hexameric peptide ligands for on-line IgG detection in bioprocesses. Surface Plasmon Resonance (SPR) was used to study the binding of human IgG to the hexameric peptide ligand HWRGWV, which was covalently grafted to alkanethiol self-assembled monolayers (SAM) on gold surfaces. [...]

Control of the Morphology of Lipid Layers by Substrate Surface Chemistry

Publication year: 2014
Authors: Niko Granqvist *†, Marjo Yliperttula †, Salla Välimäki ‡, Petri Pulkkinen ‡, Heikki Tenhu ‡, and Tapani Viitala *†
Published in: Langmuir, 2014, Vol. 30 (10), p. 2799–2809
In this study, surface coatings were used to control the morphology of the deposited lipid layers during vesicle spreading, i.e., to control if liposomes self-assemble on a surface into a supported lipid bilayer or a supported vesicular layer. [...]

Effect of gold nanoparticles on the structure and electron-transfer characteristics of glucose oxidase redox polyelectrolyte-surfactant complexes

Publication year: 2014
Authors: Cortez M.L. a,b, Marmisollé W. a, Pallarola D. b, Pietrasanta L.I. c, Murgida D.H. a, Ceolín M. b, Azzaroni O. b, Battaglini F. a
Published in: Chemistry A European Journal, 2014, Vol. 20, Issue 41, p. 13037–13404
Efficient electrical communication between redox proteins and electrodes is a critical issue in the operation and development of amperometric biosensors. The present study explores the advantages of a nanostructured redox-active polyelectrolyte-surfactant complex containing [Os(bpy)2Clpy](2+) (bpy=2,2'-bipyridine, py= pyridine) as the redox centers and gold nanoparticles (AuNPs) as nanodomains for boosting the electron-transfer propagation throughout the assembled film in the presence of glucose oxidase (GOx). [...]

Poly(l-lactide-co-2-(2-methoxyethoxy)ethyl methacrylate): A biodegradable polymer with protein resistance

Publication year: 2014
Authors: Jinbao Xua (a), Xuelin Fan (b), Jinxian Yang (b), Chunfeng Ma (a),Xiaodong Ye (b), Guangzhao Zhanga,(b)
Published in: Colloids and Surfaces B: Biointerfaces, Vol. 116 (2014), p. 531–536
We have synthesized poly(l-lactide-co-2-(2-methoxyethoxy)ethyl methacrylate) (LA-co-MEO2MA) containing both degradable and protein resistant units via hybrid copolymerization with(1-tert-butyl-4,4,4-tris(dimethylamino)-2,2-bis[tris(dimethylamino)phophoranylidenamino]-2Λ5, Λ5-catenadi(phosphazene) (t-BuP4) as the catalyst. [...]

Elucidating the Signal Responses of Multi-Parametric Surface Plasmon Resonance Living Cell Sensing: A Comparison between Optical Modeling and Drug–MDCKII Cell Interaction Measurements

Publication year: 2013
Authors: Tapani Viitala 1, Niko Granqvist 1, Susanna Hallila 1, Marjo Yliperttula 1, Manuela Raviña 2
Published in: PLoS ONE, 2013, Vol. 8(8), e72192
In vitro cell-based assays are widely used during the drug discovery and development process to test the biological activity of new drugs. Most of the commonly used cell-based assays, however, lack the ability to measure in real-time or under dynamic conditions (e.g. constant flow). In this study a multi-parameter surface plasmon resonance approach in combination with living cell sensing has been utilized for monitoring drug-cell interactions in real-time, under constant flow and without labels. [...]

Application of Paper-Supported Printed Gold Electrodes for Impedimetric Immunosensor Development

Publication year: 2013
Authors: Ihalainen P. 1, Majumdar H. 2,†, Viitala T. 3, Törngren B. 1, Närjeoja T. 4, Määttänen A. 1, Sarfraz J. 1, Härmä H. 4, Yliperttula M. 3, Österbacka R. 2, Peltonen J. 1
Published in: Biosensors, 2013, Vol. 3, p. 1-17
In this article, we report on the formation and mode-of-operation of an affinity biosensor, where alternate layers of biotin/streptavidin/biotinylated-CRP-antigen/anti-CRPantibody are grown on printed gold electrodes on disposable paper-substrates. [...]

Characterizing Ultrathin and Thick Organic Layers by Surface Plasmon Resonance Three-Wavelength and Waveguide Mode Analysis

Publication year: 2013
Authors: Niko Granqvist †, Huamin Liang †, Terhi Laurila †, Janusz Sadowski ‡, Marjo Yliperttula †, and Tapani Viitala *†
Published in: Langmuir, 29 (27), pp 8561–8571
A three-wavelength angular-scanning surface plasmon resonance based analysis has been utilized for characterizing optical properties of organic nanometer-thick layers with a wide range of thicknesses. [...]

Self-Defensive Biomaterial Coating Against Bacteria and Yeasts: Polysaccharide Multilayer Film with Embedded Antimicrobial Peptide

Publication year: 2013
Authors: Dr. G. Cado, L. Séon, Dr. T. Garnier, Dr. A. Parat,Dr. Y. Frère, Dr. L. Jierry, Prof. P. Schaaf, Dr. F. Boulmedais (1); R. Aslam, Dr. R. Fabre, A. Chassepot, Dr. J.-C. Voegel,Dr. B. Senger, Prof. P. Schaaf, Dr M.-H. Metz-Boutigue (2); Prof. F. Schneider (3); Dr. H. Kerdjoudj (4); Dr. L. Jierry, Prof. P. Schaaf, Dr. F. Boulmedais (5); Prof. P. Schaaf (6)
Published in: Advanced Functional Materials, 2013
Prevention of pathogen colonization of medical implants is a major medicaland fi nancial issue since infection by microorganisms constitutes one of the most serious complications after surgery or critical care. Immobilization ofantimicrobial molecules on biomaterials surfaces is an efficient approach to prevent biofilm formation. Herein, the first self-defensive coating against both bacteria and yeasts is reported where the release of the antimicrobial peptide is triggered by enzymatic degradation of the film due to the pathogens themselves. [...]

Rapid and sensitive detection of maize chlorotic mottle virus using surface plasmon resonance-based biosensor

Publication year: 2013
Authors: Chang Zeng (a), Xin Huang (a), Jiangmin Xu (a), Guifen Li (a), Jie Ma (a), Hai-Feng Ji (b), Shuifang Zhu (a), Hongjun Chen (a)
Published in: Analytical Biochemistry, Vol. 440 (2013), p. 18–22
We report a biosensor based on surface plasmon resonance (SPR) for the selective detection of maizechlorotic mottle virus (MCMV). [...]

Water-Wettable Polypropylene Fibers by Facile Surface Treatment Based on Soy Proteins

Publication year: 2013
Authors: Salas C. 1,3, Genzer J. 2, Lucia L.A 1, Hubbe A.M. 1, Rojas O.J. 1,2, 4
Published in: ACS Applied Materials & Interfaces, 2013, Vol. 5, p. 6541 − 6548
Modification of the wetting behavior of hydrophobic surfaces is essential in a variety of materials, including textiles and membranes that require control of fluid interactions, adhesion, transport processes, sensing, etc. This investigation examines the enhancement of wettability of animportant class of textile materials, viz., polypropylene (PP) fibers, by surface adsorption of different proteins from soybeans, including soyflour, isolate, glycinin, and β-conglycinin. [...]

Biofunctionalization of titanium surface with multilayer films modified by heparin-VEGF-fibronectin complex to improve endothelial cell proliferation and blood compatibility

Publication year: 2013
Authors: H. G. Wang (1,2), T. Y. Yin (1,2), S. P. Ge (1,2), Q. Zhang (1,2), Q. L. Dong (1,2), D. X. Lei (1,2), D. M. Sun (1,2), G. X. Wang (1,2)
Published in: Journal of Biomedical Materials Research Part A, 2013, Vol. 101A, p. 413–420
In-stent restenosis and subsequent thrombosis remain a significant complication following the implantation of coronary stents. Different approaches have been used in developing novel coronary stents to protect against thrombosis and minimize restenosis. In the present study, we designed a biomacromolecular layer-by-layer coating with heparin, vascular endothelial growth factor (VEGF), and bronectin onto nickel-free titanium surface to improve blood compatibility and endothelial cell proliferation. [...]

Self-assembly of pyridine-modified lipoic Acid derivatives on gold and their interaction with thyroxine (t4)

Publication year: 2013
Authors: Albers WM, Milani R, Tappura K, Munter T, Resnati G, Metrangolo P.
Published in: International Journal of Molecular Sciences, 2013 Feb 6;14(2):3500-13.
Pyridyl derivatives of lipoic acid were prepared as ligands for the study of the interaction with thyroxine (T4). Thin self-assembled films of the ligands were prepared in 70% ethanol on gold and their interaction with T4 was studied by titration experiments in an aqueous buffer solution using Surface Plasmon Resonance (SPR). [...]

Vesicular and non-vesicular transport feed distinct glycosylation pathways in the Golgi

Publication year: 2013
Authors: D'Angelo G. 1, Uemura T., Chuang C.C., Polishchuk E., Santoro M., Ohvo-Rekilä H., Sato T., Di Tullio G., Varriale A., D'Auria S., Daniele T., Capuani F., Johannes L., Mattjus P., Monti M., Pucci P., Williams R.L., Burke J.E., Platt F.M., Harada A., De Matteis M.A.
Published in: Nature Research Letter, 2013, Vol. 501, p. 7465
Newly synthesized proteins and lipids are transported across the Golgi complex via different mechanisms whose respective roles are not completely clear. We previously identified a non-vesicular intra-Golgi transport pathway for glucosylceramide (GlcCer)—the common precursor of the different series of glycosphingolipids—that isoperated by the cytosolic GlcCer-transfer protein FAPP2 (also known as PLEKHA8). [...]