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Hydrogel Surface (hydrogel + surface)
Selected AbstractsFunctional Hydrogel Surfaces: Binding Kinesin-Based Molecular Motor Proteins to Selected Patterned Sites,ADVANCED FUNCTIONAL MATERIALS, Issue 8 2005T. Yu Abstract Hydrogel microstructures with micrometer-scale topography and controllable functionality have great potential for numerous nanobiotechnology applications including, for example, three-dimensional structures that exhibit controlled interactions with proteins and cells. Taking advantage of the strong affinity of histidine (His) residues for metal-ion,nitrilotriacetic acid (NTA) complexes, we have chemically modified hydrogels to enable protein immobilization with retention of activity by incorporating 2-methacrylamidobutyl nitrilotriacetic acid, an NTA-containing monomer that can be copolymerized with a series of monomers to form NTA-containing hydrogels. By varying the NTA-monomer composition in the hydrogels, it is possible to control the amount of protein bound to the hydrogel surface. The retention of biological activity was demonstrated by microtubule gliding assays. Normally, hydrogels are resistant to protein binding, but we have selected these materials because of their porous nature. Bringing together hydrogel functionalization and soft-lithography patterning techniques, it was possible to create a hybrid hydrogel superstructure that possesses binding specificity to His-tagged protein in selected sites. This type of surface and microstructure is not only advantageous for motor protein integration, but it can also be generally applied to the formation of His-tagged molecules for sensors and biochip applications. [source] Direct Microfabrication of Topographical and Chemical Cues for the Guided Growth of Neural Cell Networks on Polyamidoamine HydrogelsMACROMOLECULAR BIOSCIENCE, Issue 8 2010Gabriel Dos Reis Abstract Cell patterning is an important tool for organizing cells in surfaces and to reproduce in a simple way the tissue hierarchy and complexity of pluri-cellular life. The control of cell growth, proliferation and differentiation on solid surfaces is consequently important for prosthetics, biosensors, cell-based arrays, stem cell therapy and cell-based drug discovery concepts. We present a new electron beam lithography method for the direct and simultaneous fabrication of sub-micron topographical and chemical patterns, on a biocompatible and biodegradable PAA hydrogel. The localized e-beam modification of a hydrogel surface makes the pattern able to adsorb proteins in contrast with the anti-fouling surface. By also exploiting the selective attachment, growth and differentiation of PC12 cells, we fabricated a neural network of single cells connected by neuritis extending along microchannels. E-beam microlithography on PAA hydrogels opens up the opportunity of producing multifunctional microdevices incorporating complex topographies, allowing precise control of the growth and organization of individual cells. [source] Sialic Acid Engineering of Thin Hydrogel MembranesMACROMOLECULAR RAPID COMMUNICATIONS, Issue 9 2007Stéphane Woerly Abstract We report the synthesis of glycosylated hydrogel membranes of poly{[N -(2-hydroxypropyl)methacrylamide]- co -(2-hydroxyethyl methacrylate)} with the aim of developing bioactivated polymer substrates for cell culture. 3,-Sialyllactose, the saccharidic portion of the GM3 ganglioside involved in cell-cell recognition over a wide range of biological processes, was chemically modified with an acrylate group and incorporated into the growing macromolecular network of hydrogels by free radical crosslinking copolymerization. The incorporation and accessibility of the sialic acid residues at the hydrogel surface was verified by enzyme linked immunosorbent assay using mouse monoclonal anti-GM3, and by electron microscopy after labeling with lectin-gold nanoparticles. The water content was further characterized by thermogravimetry. [source] Photopolymerization of alicyclic methacrylate hydrogels for controlled releasePOLYMERS FOR ADVANCED TECHNOLOGIES, Issue 7 2009Jing Han Abstract Alicyclic hydroxy methacrylate monomer, o -hydroxycyclohexyl methacrylate (HCMA), was synthesized and characterized by Fourier transformed infrared spectroscopy (FT-IR) and proton nuclear magnetic resonance spectroscopy (1H-NMR). Photopolymerization kinetics of HCMA was investigated via real-time infrared spectroscopy (RT-IR). Polymeric network hydrogels based on hydroxyethyl methacrylate (HEMA) and HCMA were prepared by using the photopolymerization technique. Mechanical strength, swelling characteristic, and controlled release behavior of hydrogels with various feed compositions were studied. Poly(HEMA-co-HCMA) hydrogel had higher storage modulus than that of poly(HEMA) hydrogel as investigated by dynamic mechanical analysis (DMA). Acid orange 8 was used as a model drug for the investigation of drug release behavior of copolymeric hydrogels. Results indicated that increase in HCMA ratio in hydrogel composition could reduce the swelling rate and prolong the release time. Scanning electron microscopy (SEM) was also utilized to study the surface morphology of hydrogels, and the results indicated that HCMA content influenced pore diameter on the hydrogel surface. Copyright © 2008 John Wiley & Sons, Ltd. [source] A New Approach for Adipose Tissue Regeneration Based on Human Mesenchymal Stem Cells in Contact to Hydrogels,an In Vitro Study,ADVANCED ENGINEERING MATERIALS, Issue 10 2009Kirsten Peters In this study an approach for adipose tissue regeneration based on human mesenchymal stem cells and hydrogels as supporting matrix was evaluated. The gelatin-based hydrogels developed in this study were cytocompatible and stem cell adhesion onto hydrogel surfaces was higher as compared to tissue culture polystyrene. Furthermore, the adipogenic differentiation degree was increased. These results are promising for future applications of hydrogels in adipose tissue regeneration strategies. [source] Patterned Hydrogels for Controlled Platelet Adhesion from Whole Blood and PlasmaADVANCED FUNCTIONAL MATERIALS, Issue 15 2010Tobias Ekblad Abstract This work describes the preparation and properties of hydrogel surface chemistries enabling controlled and well-defined cell adhesion. The hydrogels may be prepared directly on plastic substrates, such as polystyrene slides or dishes, using a quick and experimentally simple photopolymerization process, compatible with photolithographic and microfluidic patterning methods. The intended application for these materials is as substrates for diagnostic cell adhesion assays, particularly for the analysis of human platelet function. The non-specific adsorption of fibrinogen, a platelet adhesion promoting protein, is shown to be completely inhibited by the hydrogel, provided that the film thickness is sufficient (>5,nm). This allows the hydrogel to be used as a matrix for presenting selected bioactive ligands without risking interference from non-specifically adsorbed platelet adhesion factors, even in undiluted whole blood and blood plasma. This concept is demonstrated by preparing patterns of proteins on hydrogel surfaces, resulting in highly controlled platelet adhesion. Further insights into the protein immobilization and platelet adhesion processes are provided by studies using imaging surface plasmon resonance. The hydrogel surfaces used in this work appear to provide an ideal platform for cell adhesion studies of platelets, and potentially also for other cell types. [source] Protein Immobilization: Capturing Complex Protein Gradients on Biomimetic Hydrogels for Cell-Based Assays (Adv. Funct.ADVANCED FUNCTIONAL MATERIALS, Issue 21 2009Mater. A versatile microfluidic strategy to rapidly and selectively immobilize gradients of virtually any desired protein on soft poly(ethylene glycol) (PEG) hydrogel surfaces is developed by S. Cosson et al. on page 3411. The selectivity and orthogonality of the chosen protein immobilization schemes allows for forming parallel and orthogonal overlapping gradients of multiple proteins. This platform can be exploited to perform a wealth of cell-based assays on biomimetic surfaces. [source] Capturing Complex Protein Gradients on Biomimetic Hydrogels for Cell-Based AssaysADVANCED FUNCTIONAL MATERIALS, Issue 21 2009Steffen Cosson Abstract A versatile strategy to rapidly immobilize complex gradients of virtually any desired protein on soft poly(ethylene glycol) (PEG) hydrogel surfaces that are reminiscent of natural extracellular matrices (ECM) is reported. A microfluidic chip is used to generate steady-state gradients of biotinylated or Fc-tagged fusion proteins that are captured and bound to the surface in less than 5,min by NeutrAvidin or ProteinA, displayed on the surface. The selectivity and orthogonality of the binding schemes enables the formation of parallel and orthogonal overlapping gradients of multiple proteins, which is not possible on conventional cell culture substrates. After patterning, the hydrogels are released from the microfluidic chip and used for cell culture. This novel platform is validated by conducting single-cell migration experiments using time-lapse microscopy. The orientation of cell migration, as well as the migration rate of primary human fibroblasts, depends on the concentration of an immobilized fibronectin fragment. This technique can be readily applied to other proteins to address a wealth of biological questions with different cell types. [source] | ||||||||||