Read by QxMD icon Read

microcontact printing

Meiyu Gai, Johannes Frueh, Tianyi Tao, Arseniy V Petrov, Vladimir V Petrov, Evgeniy V Shesterikov, Sergei I Tverdokhlebov, Gleb B Sukhorukov
Long term encapsulation combined with spatiotemporal release for a precisely defined quantity of small hydrophilic molecules on demand remains a challenge in various fields ranging from medical drug delivery, controlled release of catalysts to industrial anti-corrosion systems. Free-standing individually sealed polylactic acid (PLA) nano- and microchamber arrays were produced by one-step dip-coating a PDMS stamp into PLA solution for 5 s followed by drying under ambient conditions. The wall thickness of these hydrophobic nano-microchambers is tunable from 150 nm to 7 μm by varying the PLA solution concentration...
May 17, 2017: Nanoscale
Lian Wong, John Pegan, Basia Gabela-Zuniga, Michelle Khine, Kara E McCloskey
The vascularization of tissue grafts is critical for maintaining viability of the cells within a transplanted graft. A number of strategies are currently being investigated including very promising microfluidics systems. Here, we explored the potential for generating a vasculature-patterned endothelial cells (EC) that could be integrated into distinct layers between sheets of primary cells. Bioinspired from the leaf veins, we generated a reverse mold with a fractal vascular-branching pattern that models the unique spatial arrangement over multiple length scales that precisely mimic branching vasculature...
May 10, 2017: Biofabrication
Meiyu Gai, Johannes Frueh, Valeriya L Kudryavtseva, Alexey M Yashchenok, Gleb B Sukhorukov
Efficient depot systems for entrapment and storage of small water-soluble molecules are of high demand for wide variety of applications ranging from implant based drug delivery in medicine and catalysis in chemical processes to anticorrosive systems in industry where surface-mediated active component delivery is required on a time and site specific manner. This work reports the fabrication of individually sealed hollow-structured polyelectrolyte multilayer (PEM) microchamber arrays based on layer-by-layer self-assembly as scaffolds and microcontact printing...
May 5, 2017: ACS Applied Materials & Interfaces
Shivani Sathish, Sébastien G Ricoult, Kazumi Toda-Peters, Amy Q Shen
Microfluidic systems integrated with protein and DNA micro- and nanoarrays have been the most sought-after technologies to satisfy the growing demand for high-throughput disease diagnostics. As the sensitivity of these systems relies on the bio-functionalities of the patterned recognition biomolecules, the primary concern has been to develop simple technologies that enable biomolecule immobilization within microfluidic devices whilst preserving bio-functionalities. To address this concern, we introduce a two-step patterning approach to create micro- and nanoarrays of biomolecules within microfluidic devices...
April 21, 2017: Analyst
Thuan Beng Saw, Amin Doostmohammadi, Vincent Nier, Leyla Kocgozlu, Sumesh Thampi, Yusuke Toyama, Philippe Marcq, Chwee Teck Lim, Julia M Yeomans, Benoit Ladoux
Epithelial tissues (epithelia) remove excess cells through extrusion, preventing the accumulation of unnecessary or pathological cells. The extrusion process can be triggered by apoptotic signalling, oncogenic transformation and overcrowding of cells. Despite the important linkage of cell extrusion to developmental, homeostatic and pathological processes such as cancer metastasis, its underlying mechanism and connections to the intrinsic mechanics of the epithelium are largely unexplored. We approach this problem by modelling the epithelium as an active nematic liquid crystal (that has a long range directional order), and comparing numerical simulations to strain rate and stress measurements within monolayers of MDCK (Madin Darby canine kidney) cells...
April 12, 2017: Nature
Nobuyuki Tanaka, Tadahiro Yamashita, Asako Sato, Viola Vogel, Yo Tanaka
The geometrical confinement of small cell colonies gives differential cues to cells sitting at the periphery versus the core. To utilize this effect, for example to create spatially graded differentiation patterns of human mesenchymal stem cells (hMSCs) in vitro or to investigate underpinning mechanisms, the confinement needs to be robust for extended time periods. To create highly repeatable micro-fabricated structures for cellular patterning and high-throughput data mining, we employed here a simple casting method to fabricate more than 800 adhesive patches confined by agarose micro-walls...
2017: PloS One
Fan Wu, De-Wen Zhang, Jian Wang, Michael Watkinson, Steffi Krause
A copper(I)-catalyzed azide alkyne cycloaddition (CuAAC) reaction combined with microcontact printing was used successfully to pattern alkyne-terminated self-assembled organic monolayer-modified silicon surfaces. Despite the absence of a copper peak in X-ray photoelectron spectra, copper contamination was found and visualized using light-addressable potentiometric sensors (LAPS) and scanning photo-induced impedance microscopy (SPIM) after the "click"-modified silicon surfaces were rinsed with hydrochloric acid (HCl) solution, which was frequently used to remove copper residues in the past...
March 24, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
Nikhil Bhalla, Shivani Sathish, Amy Q Shen
This work demonstrates, for the first time, the use of lithium niobate as a biosensor that detects local refractive index changes triggered by the presence of biomolecules on its surface. The sensitivity of the sensor was found to be 242±16 nm/RIU. As a case study, we immobilized proteins (IgG antibodies) using micro-contact printing to demonstrate sensing capabilities of the device. The validated proof of concept lays a foundation for developing lithium niobate based novel optical biosensors.
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
Joung-Hyun Lee, Lance C Kam
The immune synapse has emerged as a compelling example of structural complexity within cell-cell interfaces. This chapter focuses on the use of microcontact printing to isolate and investigate how spatial organization of signaling molecules drives the function of immune cells. In the process detailed here, multiple rounds of microcontact printing are combined to create patterned surfaces that control the relative spatial localization of CD3 and CD28 signaling in T cells, effectively replacing an antigen presenting cell with an engineered surface...
2017: Methods in Molecular Biology
Nikhil Bhalla, Shivani Sathish, Amy Q Shen, Nikhil Bhalla, Shivani Sathish, Amy Q Shen, Shivani Sathish, Amy Q Shen, Nikhil Bhalla
This work demonstrates, for the first time, the use of lithium niobate as a biosensor that detects local refractive index changes triggered by the presence of biomolecules on its surface. The sensitivity of the sensor was found to be 242±16 nm/RIU. As a case study, we immobilized proteins (IgG antibodies) using micro-contact printing to demonstrate sensing capabilities of the device. The validated proof of concept lays a foundation for developing lithium niobate based novel optical biosensors.
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
Gyeongyeop Han, Daehwa Hong, Bong Soo Lee, EunRae Ha, Ji Hun Park, Insung S Choi, Sung Min Kang, Jungkyu K Lee
Herein we demonstrate a systematic investigation of chemically functionalizable, non-biofouling agarose films over large-area glass surfaces. Agarose films, prepared with various concentrations of aqueous agarose, were activated by using periodate oxidation to generate aldehyde groups at the termini of the agarose chains. The non-biofouling efficacy and binding capabilities of the activated films were evaluated by using protein and cellular patterning, performed by using a microarrayer, microcontact printing, and micromolding in capillaries...
February 20, 2017: Chemistry, An Asian Journal
Peng Xiao, Nianxiang Qiu, Jincui Gu, Shuai Wang, Jiang He, Chih-Feng Huang, Jiawei Zhang, Youju Huang, Tao Chen
Graphene oxide (GO), which is structurally analogous to graphene, was used as the ink to precisely tune the surface activity of graphene, without diminishing the outstanding properties of the 2D sp(2) network, via microcontact printing-induced multiple π-π stacking interactions. The GO/graphene hybrids, thus, provide a robust platform for chemical/photo-active GO for further chemical modification with multifunctionality.
January 26, 2017: Chemical Communications: Chem Comm
Inga Lilge, Siyu Jiang, Holger Schönherr
The fabrication of 3D cell microenvironments exploiting versatile, long-term stable passivating poly(acryl amide) brushes in a microwell format and the study of the behavior of fibroblast and pancreatic tumor cells in wells of systematically varied shape and size is reported. The microwells, which are obtained by combining micromolding in capillaries with microcontact printing of initiator monolayers for subsequent surface-initiated polymerization of acrylamide and controlled functionalization with fibronectin (FN), expose cell adhesive areas inside the wells and protein and cell resistant brushes on the topside plateaus...
January 3, 2017: Macromolecular Bioscience
Yuksel Temiz, Robert D Lovchik, Emmanuel Delamarche
The miniaturization of immunoassays using microfluidic devices is attractive for many applications, but an important challenge remains the patterning of capture antibodies (cAbs) on the surface of microfluidic structures. Here, we describe how to pattern cAbs on planar poly(dimethylsiloxane) (PDMS) stamps and how to microcontact print the cAbs on a dry-film resist (DFR). DFRs are new types of photoresists having excellent chemical resistance and good mechanical, adhesive, and optical properties. Instead of being liquid photoresists, DFRs are thin layers that are easy to handle, cut, photo-pattern, and laminate over surfaces...
2017: Methods in Molecular Biology
Yongqing Xia, Ying Tang, Han Wu, Jing Zhang, Zongyi Li, Fang Pan, Shengjie Wang, Xiaojuan Wang, Hai Xu, Jian Ren Lu
Interfaces between materials and cells play a critical role in cell biomedical applications. Here, a simple, robust, and cost-effective method is developed to fabricate patterned thermoresponsive poly(N-isopropylacrylamide-co-styrene) microgel strips on a polyethyleneimine-precoated, non-thermoresponsive cell-adherent glass coverslip. The aim is to investigate whether cell sheets could be harvested from these cell-adherent surfaces patterned with thermoresponsive strips comprised of the microgels. We hypothesize that if the cell-to-cell interaction is strong enough to retain the whole cell sheet from disintegration, the cell segments growing on the thermoresponsive strips may drag the cell segments growing on the cell-adherent gaps to detach, ending with a whole freestanding and transferable cell sheet...
January 18, 2017: ACS Applied Materials & Interfaces
T P Vinod, Jay M Taylor, Abhiteja Konda, Stephen A Morin
The directed assembly of micro-/nanoscale objects relies on physical or chemical processes to generate structures that are not possible via self-assembly alone. A relatively unexplored strategy in directed assembly is the "active" manipulation of building blocks through deformations of elastomeric substrates. This manuscript reports a method which uses macroscopic mechanical deformations of chemically modified silicone films to realize the rational assembly of microscopic polymer structures. Specifically, polystyrene microparticles are deposited onto polydimethylsiloxane substrates using microcontact-printing where, through a process that involved stretching/relaxing the substrates and bonding of the particles, they are elaborated into microstructures of various sizes, shapes, symmetries, periodicities, and functionalities...
February 2017: Small
Meiyu Gai, Johannes Frueh, Valeriya L Kudryavtseva, Rui Mao, Maxim V Kiryukhin, Gleb B Sukhorukov
Polyelectrolyte complexes (PEC) are formed by mixing the solutions of oppositely charged polyelectrolytes, which were hitherto deemed "impossible" to process, since they are infusible and brittle when dry. Here, we describe the process of fabricating free-standing micro-patterned PEC films containing array of hollow or filled microchambers by one-step casting with small applied pressure and a PDMS mould. These structures are compared with polyelectrolyte multilayers (PEM) thin films having array of hollow microchambers produced from a layer-by-layer self-assembly of the same polyelectrolytes on the same PDMS moulds...
November 10, 2016: Scientific Reports
Moritz Buhl, Matthias Tesch, Sebastian Lamping, Johanna Moratz, Armido Studer, Bart Jan Ravoo
This paper reports microcontact printing (μCP) to immobilize an alkoxyamine initiator (regulator) on glass and silicon substrates and subsequent surface-initiated alternating nitroxide-mediated copolymerization (siNMP) of hexafluoroisopropyl acrylate (HFIPA) and 7-octenylvinyl ether (OVE). The resulting patterned polymer brushes are analyzed by using atomic force microscopy (AFM). In addition, site-specific post-functionalization of the alternating polymer brushes by applying two orthogonal surface reactions is achieved with thiols and amines through μCP...
May 2, 2017: Chemistry: a European Journal
Richard Gondosiswanto, Christian A Gunawan, David B Hibbert, Jason B Harper, Chuan Zhao
Lab-on-a-chip systems have gained significant interest for both chemical synthesis and assays at the micro-to-nanoscale with a unique set of benefits. However, solvent volatility represents one of the major hurdles to the reliability and reproducibility of the lab-on-a-chip devices for large-scale applications. Here we demonstrate a strategy of combining nonvolatile and functionalized ionic liquids with microcontact printing for fabrication of "wall-less" microreactors and microfluidics with high reproducibility and high throughput...
November 16, 2016: ACS Applied Materials & Interfaces
Yujie Zhu, Jose M Moran-Mirabal
Supported lipid bilayers (SLBs) provide an excellent model system for studying structural and functional characteristics of biomembranes. Patterning model membranes on solid supports has elicited much interest because lipid bilayer arrays at cellular or sub-cellular scales provide attractive platforms for reconstituting tissue-like conditions for cell culture, and for creating simplified physiological environments to study biological processes. Phase-segregated SLB patterns can be especially useful for such studies, as the selective functionalization of the lipid phases with different lipids, receptors or proteins can be achieved to mimic the key features of plasma membrane...
October 4, 2016: Langmuir: the ACS Journal of Surfaces and Colloids
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"