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microcontact printing

D John, M Zimmermann, A Böker
A simple route towards patchy particles with anisotropic patches with respect to a different functionality and directionality is presented. This method is based on microcontact printing of positively charged polyethylenimine (PEI) on silica particles using wrinkled stamps. Due to the wrinkled surface, the number of patches on the particles as well as the distance between two patches can be controlled.
April 16, 2018: Soft Matter
David Moore, Ravi F Saraf
Microcontact printing (µCP) is a valuable technique used to fabricate complex patterns on surfaces for applications such as sensors, cell seeding, self-assembled monolayers of proteins and nanoparticles, and micromachining. The process is very precise but is typically confined to depositing a single type of ink per print, which limits the complexity of using multifunctionality patterns. Here we describe a process by which two inks are printed concomitantly in a single operation to create an alternating pattern of hydrophobic and hydrophilic characteristics...
April 4, 2018: ACS Applied Materials & Interfaces
Adriana R Kyvik, Carlos Luque-Corredera, Daniel Pulido, Miriam Royo, Jaume Veciana, Judith Guasch, Imma Ratera
Stimuli-responsive self-assembled monolayers (SAMs) are used to confer switchable physical, chemical, or biological properties to surfaces through the application of external stimuli. To obtain spatially and temporally tunable surfaces, we present microcontact printed SAMs of an hydroquinone molecule that are used as a dynamic interface to immobilize different functional molecules either via Diels Alder or Michael thiol addition reactions upon the application of a low potential. In spite of the use of such reactions and the potential applicability of the resulting surfaces in different fields ranging from sensing to biomedicine through data storage or clean up, a direct comparison of the two functionalization strategies on a surface has not yet been performed...
April 4, 2018: Journal of Physical Chemistry. B
Andres Canales, Seongjun Park, Antje Kilias, Polina Anikeeva
Multifunctional devices for modulation and probing of neuronal activity during free behavior facilitate studies of functions and pathologies of the nervous system. Probes composed of stiff materials, such as metals and semiconductors, exhibit elastic and chemical mismatch with the neural tissue, which is hypothesized to contribute to sustained tissue damage and gliosis. Dense glial scars have been found to encapsulate implanted devices, corrode their surfaces, and often yield poor recording quality in long-term experiments...
March 21, 2018: Accounts of Chemical Research
Maria E Piroli, Ehsan Jabbarzadeh
Human stem cells hold significant potential for the treatment of various diseases. However, their use as a therapy is hampered because of limited understanding of the mechanisms by which they respond to environmental stimuli. Efforts to understand extracellular biophysical cues have demonstrated the critical roles of geometrical and mechanical signals in determining the fate of stem cells. The goal of this study was to explore the interplay between cell polarity and matrix stiffness in stem cell lineage specification...
June 2018: Annals of Biomedical Engineering
Marc Zimmermann, Daniela John, Dmitry Grigoriev, Nikolay Puretskiy, Alexander Böker
A straightforward approach for the precise multifunctional surface modification of particles with three-dimensional patches using microcontact printing is presented. By comparison to previous works it was possible to not only control the diameter, but also to finely tune the thickness of the deposited layer, opening up the way for three-dimensional structures and orthogonal multifunctionality. The use of PEI as polymeric ink, PDMS stamps for microcontact printing on silica particles and the influence of different solvents during particle release on the creation of functional particles with three-dimensional patches are described...
March 28, 2018: Soft Matter
Junfei Xia, Yuting Qiu, Xiaojie Xun, Liyuan Ma, Jingjiao Guan, Ming Su
Cell population based toxicity assays cannot distinguish responses of single cells and sub-cellular organelles; while single cell assays are limited by low statistical power due to small number of cells examined. This article reports a new single cell array based toxicity assay, in which cell responses at population level, single cell level and sub-cellular level can be obtained simultaneously at high throughput. The single cell array was produced by microcontact printing and selected area cell attachment, and exposed to damaging X-ray radiation, which was followed by fluorescence imaging after staining...
May 12, 2018: Analytica Chimica Acta
Christoph Buten, Sebastian Lamping, Martin Körsgen, Heinrich F Arlinghaus, Craig Jamieson, Bart Jan Ravoo
In this paper, we show that carboxylic acid-functionalized molecules can be patterned by photochemical microcontact printing on tetrazole-terminated self-assembled monolayers. Upon irradiation, tetrazoles eliminate nitrogen to form highly reactive nitrile imines, which can be ligated with several different nucleophiles, carboxylic acids being the most reactive. As a proof of concept, we immobilized trifluoroacetic acid to monitor the reaction with X-ray photoelectron spectroscopy. Moreover, we also immobilized peptides and fabricated carbohydrate-lectin as well as biotin-streptavidin microarrays using this method...
February 6, 2018: Langmuir: the ACS Journal of Surfaces and Colloids
Shuhuan Hu, Ting-Hsuan Chen, Yanhua Zhao, Zuankai Wang, Raymond H W Lam
Microcontact printing (μCP) is widely used to create patterns of biomolecules essential for studies of cell mechanics, migration, and tissue engineering. However, different types of μCPs may create micropatterns with varied protein-substrate adhesion, which may change cell behaviors and pose uncertainty in result interpretation. Here, we characterize two μCP methods for coating extracellular matrix (ECM) proteins (stamp-off and covalent bond) and demonstrate for the first time the important role of protein-substrate adhesion in determining cell behavior...
January 30, 2018: Langmuir: the ACS Journal of Surfaces and Colloids
Jens Moeller, Aleksandra K Denisin, Joo Yong Sim, Robin E Wilson, Alexandre J S Ribeiro, Beth L Pruitt
Polyacrylamide gels functionalized with extracellular matrix proteins are commonly used as cell culture platforms to evaluate the combined effects of extracellular matrix composition, cell geometry and substrate rigidity on cell physiology. For this purpose, protein transfer onto the surface of polyacrylamide hydrogels must result in geometrically well-resolved micropatterns with homogeneous protein distribution. Yet the outcomes of micropatterning methods have not been pairwise evaluated against these criteria...
2018: PloS One
Nikhil Bhalla, Shivani Sathish, Casey James Galvin, Robert Anthony Campbell, Abhishek Sinha, Amy Q Shen
Large-scale plasmonic substrates consisting of metal-insulator nanostructures coated with a bio-recognition layer can be exploited for enhanced label-free sensing, by utilizing the principle of localized surface plasmon resonance (LSPR). Most often the uniformity and thickness of the bio-recognition layer determines the sensitivity of plasmonic resonances as the inherent LSPR sensitivity of nanomaterials is limited to 10-20 nm from the surface. However, due to time-consuming nanofabrication processes, there is limited work on both the development of large-scale plasmonic materials, and the subsequent surface functionalizing with bio-recognition layers...
December 13, 2017: ACS Applied Materials & Interfaces
Lidia Escutia-Guadarrama, Genaro Vázquez-Victorio, David Martínez-Pastor, Brenda Nieto-Rivera, Marcela Sosa-Garrocho, Marina Macías-Silva, Mathieu Hautefeuille
We present the rapid-prototyping of type I collagen micropatterns on poly-dimethylsiloxane substrates for the biomimetic confinement of cells using the combination of a surface oxidation treatment and 3-aminopropyl triethoxysilane silanisation followed by glutaraldehyde crosslinking. The aim of surface treatment is to stabilise microcontact printing transfer of this natural extracellular matrix protein that usually wears out easily from poly-dimethylsiloxane, which is not suitable for biomimetic cell culture platforms and lab-on-chip applications...
January 2017: Journal of Tissue Engineering
S Neupane, P Losada-Pérez, S Vivegnis, Z Mekhalif, J Delhalle, A Bashir, F U Renner
Controlling the molecular organization of organic self-assembled monolayers (SAM) is of utmost importance in nanotechnology, molecular electronics, and surface science. Here we propose two well-differentiated approaches, double printing based on microcontact printing (μ-cp) and molecular backfilling adsorption, to produce complex alkanethiol films. The resulting films on model Au surfaces were characterized by atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), and contact angle measurements...
January 9, 2018: Langmuir: the ACS Journal of Surfaces and Colloids
Richard Gondosiswanto, D Brynn Hibbert, Yu Fang, Chuan Zhao
Ionic liquids (IL) have been regarded as promising electrolytes as substitutes for volatile aqueous or organic solvents for electrochemical gas sensors. However, ILs are viscous, and the slow diffusion of gas molecules leads to poor sensitivity and sluggish response times. Herein, we describe a strategy using an array of microstrips of IL containing magnetic nanoparticles as nanostirrers for enhanced mass transport and gas sensing. Magnetic CoFe2 O4 nanoparticles are synthesized and dispersed in a hydrophobic IL [BMP][Ntf2 ]...
December 13, 2017: ACS Applied Materials & Interfaces
Wilke C de Vries, Matthias Tesch, Armido Studer, Bart Jan Ravoo
We present the preparation of ligand-conjugated redox-responsive polymer nanocontainers by the supramolecular decoration of cyclodextrin vesicles with a thin redox-cleavable polymer shell that displays molecular recognition units on its surface. Two widely different recognition motifs (mannose-Concanavalin A and biotin-streptavidin) are compared and the impact of ligand density on the nanocontainer surface as well as an additional functionalization with nonadhesive poly(ethylene glycol) is studied. Aggregation assays, dynamic light scattering, and a fluorometric quantification reveal that the molecular recognition of ligand-conjugated polymer nanocontainers by receptor proteins is strongly affected by the multivalency of interactions and the association strength of the recognition motif...
December 6, 2017: ACS Applied Materials & Interfaces
Elaine J Su, Amy E Herr
Cell-matrix and cell-cell interactions influence intracellular signalling and play an important role in physiologic and pathologic processes. Detachment of cells from the surrounding microenvironment alters intracellular signalling. Here, we demonstrate and characterise an integrated microfluidic device to culture single and clustered cells in tuneable microenvironments and then directly analyse the lysate of each cell in situ, thereby eliminating the need to detach cells prior to analysis. First, we utilise microcontact printing to pattern cells in confined geometries...
December 5, 2017: Lab on a Chip
Tony W Hsiao, Patrick A Tresco, Vladimir Hlady
The surface concentration gradient of two extracellular matrix (ECM) macromolecules was developed to study the migratory and morphological responses of astrocytes to molecular cues typically found in the central nervous system injury environment. The gradient, prepared using microcontact printing, was composed of randomly positioned micrometer-sized dots of aggrecan (AGG) printed on a substrate uniformly coated with laminin (LN). AGG dots were printed in an increasing number along the 1000 μm long and 50 μm wide gradient area which had on each end either a full surface coverage of AGG or LN...
September 11, 2017: Biointerphases
Victor M Aguilar, Benjamin D Cosgrove
Adult muscle stem cells (also called satellite cells) are an anatomically defined population of cells that are essential for muscle regeneration. In aging and dystrophic diseases, muscle stem cells (MuSCs) exhibit functional and molecular heterogeneity; therefore, single-cell assay technologies are critical to illuminate the mechanisms of pathological stem cell dysfunction. Here, we describe the process of generating mechanically tunable hydrogels with micro-scale well features ("microwells") using micro-contact printing for clonal muscle stem cell culture assays...
2017: Methods in Molecular Biology
Miquel Avella-Oliver, Javier Carrascosa, Rosa Puchades, Ángel Maquieira
A novel label-free biosensing approach based on bioreceptor networks patterned as diffractive gratings (biogratings) has been developed. Nanogrooved structures were used as optically active scaffolds for producing arrays of functional BSA biogratings on low energy surfaces by a water-assisted variant of microcontact printing. An analytical scanner, comprising a LightScribe compact disk drive, was developed to measure the diffraction patterns of these biogratings, thus allowing biointeractions to be quantitatively sensed in a multiplex and label-free fashion by means of diffraction efficiency changes...
September 5, 2017: Analytical Chemistry
Anthony Fernandez, Markville Bautista, Ramunas Stanciauskas, Taerin Chung, Fabien Pinaud
Patterning cells on microcontact-printed substrates is a powerful approach to control cell morphology and introduce specific mechanical cues on a cell's molecular organization. Although global changes in cellular architectures caused by micropatterns can easily be probed with diffraction-limited optical microscopy, studying molecular reorganizations at the nanoscale demands micropatterned substrates that accommodate the optical requirements of single molecule microscopy techniques. Here, we developed a simple micropatterning strategy that provides control of cellular architectures and is optimized for nanometer accuracy single molecule tracking and three-dimensional super-resolution imaging of plasma and nuclear membrane proteins in cells...
August 9, 2017: ACS Applied Materials & Interfaces
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