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H Yamamoto, R Matsumura, H Takaoki, S Katsurabayashi, A Hirano-Iwata, M Niwano
The structure and connectivity of cultured neuronal networks can be controlled by using micropatterned surfaces. Here, we demonstrate that the direction of signal propagation can be precisely controlled at a single-cell resolution by growing primary neurons on micropatterns. To achieve this, we first examined the process by which axons develop and how synapses form in micropatterned primary neurons using immunocytochemistry. By aligning asymmetric micropatterns with a marginal gap, it was possible to pattern primary neurons with a directed polarization axis at the single-cell level...
July 25, 2016: Applied Physics Letters
Fred Etoc, Jakob Metzger, Albert Ruzo, Christoph Kirst, Anna Yoney, M Zeeshan Ozair, Ali H Brivanlou, Eric D Siggia
The earliest aspects of human embryogenesis remain mysterious. To model patterning events in the human embryo, we used colonies of human embryonic stem cells (hESCs) grown on micropatterned substrate and differentiated with BMP4. These gastruloids recapitulate the embryonic arrangement of the mammalian germ layers and provide an assay to assess the structural and signaling mechanisms patterning the human gastrula. Structurally, high-density hESCs localize their receptors to transforming growth factor β at their lateral side in the center of the colony while maintaining apical localization of receptors at the edge...
October 13, 2016: Developmental Cell
Elena Scarpa, Alice Roycroft, Eric Theveneau, Emmanuel Terriac, Matthieu Piel, Roberto Mayor
No abstract text is available yet for this article.
October 15, 2016: Biology Open
Katrin Niegelhell, Michael Suessenbacher, Katrin Jammernegg, Thomas Ganner, Daniel Schwendenwein, Helmut Schwab, Franz Stelzer, Harald Plank, Stefan Spirk
The creation of nano- and micropatterned polymer films is a crucial step for innumerous applications in science and technology. However, there are several problems associated with environmental aspects concerning the polymer synthesis itself, crosslinkers to induce the patterns as well as toxic solvents used for the preparation and even more important development of the films (e.g. chlorobenzene). In this paper, we present a facile method to produce micro- and nanopatterned biopolymer thin films using enzymes as so called biodevelopers...
October 13, 2016: Biomacromolecules
Alessia Deglincerti, Fred Etoc, M Cecilia Guerra, Iain Martyn, Jakob Metzger, Albert Ruzo, Mijo Simunovic, Anna Yoney, Ali H Brivanlou, Eric Siggia, Aryeh Warmflash
Fate allocation in the gastrulating embryo is spatially organized as cells differentiate into specialized cell types depending on their positions with respect to the body axes. There is a need for in vitro protocols that allow the study of spatial organization associated with this developmental transition. Although embryoid bodies and organoids can exhibit some spatial organization of differentiated cells, methods that generate embryoid bodies or organoids do not yield consistent and fully reproducible results...
November 2016: Nature Protocols
Ying Chen, Zhiyang Zhao, Alamgir Karim, R A Weiss
Surface memory effects for micropattern and nanopattern are demonstrated for shape memory compounds composed of mixtures of the zinc salt of a sulfonated poly(ethylene-co-propylene-co-ethylidene norbornene) ionomer and three different low molar mass fatty acids (FAs): lauric acid (LA), stearic acid (SA), and zinc stearate (ZnSt). This work shows the ability to tune the surface pattern switching temperature (Tc ) by simply varying the FA melting point. The melting point of the FA in the ionomer compound is depressed from that of the pure FA due to strong dipolar interactions between the ionomer and the FAs...
October 10, 2016: Macromolecular Rapid Communications
Yu Xia, Gerardo Cedillo-Servin, Randall D Kamien, Shu Yang
Two-dimensional liquid crystal elastomer (LCE) sheets with preprogrammed topological defects are prepared by aligning liquid crystal monomers within micropatterned epoxy channels, followed by photopolymerization. Upon heating, the LCE films form various three-dimensional structures in agreement with theoretical design. The miniaturized LCE actuators offer large area work capacities (≈1.05 J m(-2) ) to lift over 700 times their own weight.
September 15, 2016: Advanced Materials
Zhi-Chun Shao, Yan Zhao, Wanyu Zhang, Yanping Cao, Xi-Qiao Feng
Sinusoidal wrinkling will occur in a planar film-substrate bilayer when the uniaxial compressive strain imposed to the system exceeds a critical value. However, when a core-shell soft cylinder is subjected to axial compression, surface wrinkling patterns may evolve from the sinusoidal mode to the diamond-like mode, depending on the modular ratio and the curvature of the system. Inspired by this phenomenon, we here propose a simple yet robust strategy to fabricate hierarchical wrinkling patterns by controlling the curvature of a film-substrate system...
September 28, 2016: Soft Matter
Tatjana J Autenrieth, Stephanie C Frank, Alexandra M Greiner, Dominik Klumpp, Benjamin Richter, Mario Hauser, Seong-Il Lee, Joel Levine, Martin Bastmeyer
Although much is known about chemotaxis- induced by gradients of soluble chemical cues - the molecular mechanisms involved in haptotaxis (migration induced by substrate-bound protein gradients) are largely unknown. We used micropatterning to produce discontinuous gradients consisting of μm-sized fibronectin-dots arranged at constant lateral but continuously decreasing axial spacing. Parameters like gradient slope, protein concentration and size or shape of the fibronectin dots were modified to determine optimal conditions for directional cell migration in gradient patterns...
October 10, 2016: Integrative Biology: Quantitative Biosciences From Nano to Macro
Richard De Mets, Katharina Hennig, Lionel Bureau, Martial Balland
Mechanical interactions between cells and their microenvironment are crucial for fundamental biological processes ranging from migration to differentiation. This has led, over the last decades, to the development of new ways to culture cells. Living cells are now grown not only on glass coverslips, where they completely lose the mechanical and geometrical constraints coming from their microenvironment, but also on soft patterned substrates that mimic the rigidity and spatial information of their in vivo niches...
October 18, 2016: Biomaterials Science
Daniel F Milano, Robert J Natividad, Yasuhiro Saito, Catherine Y Luo, Senthil K Muthuswamy, Anand R Asthagiri
Epithelial-mesenchymal transition (EMT) is a complex process by which cells acquire invasive properties that enable escape from the primary tumor. Complete EMT, however, is not required for metastasis: circulating tumor cells exhibit hybrid epithelial-mesenchymal states, and genetic perturbations promoting partial EMT induce metastasis in vivo. An open question is whether and to what extent intermediate stages of EMT promote invasiveness. Here, we investigate this question, building on recent observation of a new invasive property...
October 4, 2016: Biophysical Journal
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
Metin Uz, Anup D Sharma, Pratish Adhikari, Donald S Sakaguchi, Surya K Mallapragada
: In this study, a poly(lactic acid) (PLLA) porous film with longitudinal surface micropatterns was fabricated by a dry phase inversion technique to be used as potential conduit material for peripheral nerve regeneration applications. The presence of a nerve growth factor (NGF) gradient on the patterned film surface and protein loaded, surface-eroding, biodegradable, and amphiphilic polyanhydride (PA) microparticles within the film matrix, enabled co-delivery of neurotrophic factors with controlled release properties and enhanced neurite outgrowth from PC12 cells...
September 29, 2016: Acta Biomaterialia
Meredith A Roberts, Surya S Kotha, Kiet T Phong, Ying Zheng
In vitro platforms to study endothelial cells and vascular biology are largely limited to 2D endothelial cell culture, flow chambers with polymer or glass based substrates, and hydrogel-based tube formation assays. These assays, while informative, do not recapitulate lumen geometry, proper extracellular matrix, and multi-cellular proximity, which play key roles in modulating vascular function. This manuscript describes an injection molding method to generate engineered vessels with diameters on the order of 100 µm...
2016: Journal of Visualized Experiments: JoVE
Julie Fredonnet, Julie Foncy, Jean-Christophe Cau, Childérick Séverac, Jean Marie François, Emmanuelle Trévisiol
Microarrays are established research tools for genotyping, expression profiling, or molecular diagnostics in which DNA molecules are precisely addressed to the surface of a solid support. This study assesses the fabrication of low-density oligonucleotide arrays using an automated microcontact printing device, the InnoStamp 40(®). This automate allows a multiplexed deposition of oligoprobes on a functionalized surface by the use of a MacroStamp(TM) bearing 64 individual pillars each mounted with 50 circular micropatterns (spots) of 160 µm diameter at 320 µm pitch...
2016: Microarrays
Fiona M Watt
Mammalian epidermis is maintained through proliferation of stem cells and differentiation of their progeny. The balance between self-renewal and differentiation is controlled by a variety of interacting intrinsic and extrinsic factors. Although the nature of these interactions is complex, they can be modeled in a reductionist fashion by capturing single epidermal stem cells on micropatterned substrates and exposing them to individual stimuli, alone or in combination, over defined time points. These studies have shown that different extrinsic stimuli trigger a common outcome-initiation of terminal differentiation-by activating different signaling pathways and eliciting different transcriptional responses...
September 26, 2016: Developmental Cell
Carlos Carbonell, Adam B Braunschweig
Future nanomanufacturing tools will prepare organic materials with complex four-dimensional (4D) structure, where the position (x, y, z) and chemical composition within a volume is controlled with sub-1 μm spatial resolution. Such tools could produce substrates that mimic biological interfaces, like the cell surface or the extracellular matrix, whose topology and chemical complexity combine to direct some of the most sophisticated biological events. The control of organic materials at the nanoscale-level of spatial resolution could revolutionize the assembly of next generation optical and electronic devices or substrates for tissue engineering or enable fundamental biological or material science investigations...
September 19, 2016: Accounts of Chemical Research
Greg M Harris, Nicolas N Madigan, Karen Z Lancaster, Lynn W Enquist, Anthony J Windebank, Jeffrey Schwartz, Jean E Schwarzbauer
Spinal cord and peripheral nerve injuries require the regeneration of nerve fibers across the lesion site for successful recovery. Providing guidance cues and soluble factors to promote neurite outgrowth and cell survival can enhance repair. The extracellular matrix (ECM) plays a key role in tissue repair by controlling cell adhesion, motility, and growth. In this study, we explored the ability of a mesenchymal ECM to support neurite outgrowth from neurons in the superior cervical ganglia (SCG). Length and morphology of neurites extended on a decellularized fibroblast ECM were compared to those on substrates coated with laminin, a major ECM protein in neural tissue, or fibronectin, the main component of a mesenchymal ECM...
September 15, 2016: Matrix Biology: Journal of the International Society for Matrix Biology
Satoshi Watanabe, Munetoyo Iida, Mutsuyoshi Matsumoto
We discuss an alternate method for calcification in microcapillaries for fabricating calcium phosphate films using silicone molds and calcifying solutions. Calcium phosphate films with a line/space of 5-50 µm were fabricated by controlling the concentrations of calcium chloride and sodium phosphate solutions. Plate-type crystals of hydroxyapatite were grown when the calcium phosphate films were immersed in hydroxyapatite precursors. In the initial stage of hydroxyapatite crystal growth, the c-plane of the crystals was grown parallel to the substrates, and subsequently the growth followed with the c-plane growing perpendicular to the substrates...
October 1, 2016: Journal of Oleo Science
Chenchu Zhang, Yanlei Hu, Wenqiang Du, Peichao Wu, Shenglong Rao, Ze Cai, Zhaoxin Lao, Bing Xu, Jincheng Ni, Jiawen Li, Gang Zhao, Dong Wu, Jiaru Chu, Koji Sugioka
Rapid integration of high-quality functional devices in microchannels is in highly demand for miniature lab-on-a-chip applications. This paper demonstrates the embellishment of existing microfluidic devices with integrated micropatterns via femtosecond laser MRAF-based holographic patterning (MHP) microfabrication, which proves two-photon polymerization (TPP) based on spatial light modulator (SLM) to be a rapid and powerful technology for chip functionalization. Optimized mixed region amplitude freedom (MRAF) algorithm has been used to generate high-quality shaped focus field...
2016: Scientific Reports
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