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Hydrogel Membranes (hydrogel + membrane)

Distribution by Scientific Domains
Polymers and Materials Science71%

Selected Abstracts

Sialic Acid Engineering of Thin Hydrogel Membranes

MACROMOLECULAR RAPID COMMUNICATIONS, Issue 9 2007
Stéphane 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]

Mathematical Model for Surface-Initiated Photopolymerization of Poly(ethylene glycol) Diacrylate

MACROMOLECULAR THEORY AND SIMULATIONS, Issue 9 2006
Seda K
Abstract Summary: A general mathematical model has been developed to describe the surface initiated photopolymerization of PEG-DA forming crosslinked hydrogel membranes upon the surface of a substrate. Such membranes are formed by photopolymerizing a PEG-DA prepolymer solution by initiation with eosin-Y-functionalized surfaces and TEA using VP as accelerator. Experimental measurements of the thickness of hydrogel membranes compare well with the model. The model is developed by using the pseudo-kinetic approach and the method of moments, and is capable of predicting the crosslink density and thickness of the hydrogel membrane. Parametric sensitivity of the effects of PEG-DA, VP and coinitiator TEA concentration towards the crosslink density and the thickness of the hydrogel is also investigated. The results obtained for different PEG-DA and VP concentrations suggest that the concentration ratio of these two monomers is a key parameter in controlling the gel thickness and permeability. This model can also be applied to systems where drugs, proteins or cells are encapsulated through surface initiated photopolymerization to predict the growth and crosslink density profiles of the encapsulating membrane. In a previous study we have experimentally demonstrated that these membranes could be made to attach covalently to the surface of the underlying substrate. Comparison of experimental measurements and model simulation of PEG-DA hydrogel membrane thickness versus laser duration at high PEG-DA concentrations. [source]

Diffusional properties of chitosan hydrogel membranes

JOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 6 2001
Barbara Krajewska
Abstract Chitosan membranes were prepared by a solvent evaporation technique, followed by crosslinking with glutaraldehyde and coating with BSA. The effects of crosslinking and BSA coating on the pore structure of such prepared hydrogel chitosan membranes were determined. The diffusion rates of 12 non-electrolytes ranging in molecular radius between 2.5 and 14,Å through the membranes were measured, and the results were interpreted in terms of the capillary pore model and free volume model of solute diffusional transport through hydrogel membranes. Glutaraldehyde crosslinking was found to reduce the membrane water content and consequently the membrane pore size and surface porosity, whereas further BSA coating brought about the opposite effect. The latter effect lessened with an increase in glutaraldehyde pretreatment of the membranes. The optimal chitosan membrane preparation, compromising between the solute flux and membrane stability and durability was obtained when the membranes were crosslinked with glutaraldehyde at concentrations between 0.01 and 0.1% (w/w). The knowledge of transport properties and of physical strength of the membranes is of importance for the development of chitosan-based controlled release systems. © 2001 Society of Chemical Industry [source]

Sialic Acid Engineering of Thin Hydrogel Membranes

MACROMOLECULAR RAPID COMMUNICATIONS, Issue 9 2007
Stéphane 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]

Mathematical Model for Surface-Initiated Photopolymerization of Poly(ethylene glycol) Diacrylate

MACROMOLECULAR THEORY AND SIMULATIONS, Issue 9 2006
Seda K
Abstract Summary: A general mathematical model has been developed to describe the surface initiated photopolymerization of PEG-DA forming crosslinked hydrogel membranes upon the surface of a substrate. Such membranes are formed by photopolymerizing a PEG-DA prepolymer solution by initiation with eosin-Y-functionalized surfaces and TEA using VP as accelerator. Experimental measurements of the thickness of hydrogel membranes compare well with the model. The model is developed by using the pseudo-kinetic approach and the method of moments, and is capable of predicting the crosslink density and thickness of the hydrogel membrane. Parametric sensitivity of the effects of PEG-DA, VP and coinitiator TEA concentration towards the crosslink density and the thickness of the hydrogel is also investigated. The results obtained for different PEG-DA and VP concentrations suggest that the concentration ratio of these two monomers is a key parameter in controlling the gel thickness and permeability. This model can also be applied to systems where drugs, proteins or cells are encapsulated through surface initiated photopolymerization to predict the growth and crosslink density profiles of the encapsulating membrane. In a previous study we have experimentally demonstrated that these membranes could be made to attach covalently to the surface of the underlying substrate. Comparison of experimental measurements and model simulation of PEG-DA hydrogel membrane thickness versus laser duration at high PEG-DA concentrations. [source]

The controlled release behavior and pH- and thermo-sensitivity of alginate/poly(vinyl alcohol) blended hydrogels

POLYMERS FOR ADVANCED TECHNOLOGIES, Issue 8 2009
Win-Chun Jao
Abstract Poly(vinyl alcohol) (PVA) was blended with sodium alginate (Alg) in various ratios and crosslinked with calcium chloride and made into hydrogel membranes. The dependence of the swelling behavior of these Alg-Ca/PVA hydrogels on pH was investigated. The temperature-dependent swelling behavior of the semi-interpenetrating network (semi-IPN) hydrogels was examined at temperatures from 2 to 45°C and the enthalpy of mixing (,Hmix) was determined at various temperatures. The molecular structure of the hydrogels was studied by infrared spectroscopy and their water structure in the semi-IPN hydrogels was measured by differential scanning calorimetry (DSC). The influence of Ca2+ content on the network structure of Alg-Ca/PVA hydrogels was investigated in terms of the compressive elastic modulus, effective crosslinking density, and the polymer,solvent interaction parameter based on the Flory theory. The loading of alizarin red S (ARS) followed the Langmuir isotherm mechanism and the release kinetics of ARS from the Alg-Ca/PVA hydrogels followed the Fickian diffusion mechanism. Copyright © 2008 John Wiley & Sons, Ltd. [source]