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Polymer Hydrogels (polymer + hydrogel)

Distribution by Scientific Domains

Polymers and Materials Science	75%

Selected Abstracts

Influence of Solute Charge and Hydrophobicity on Partitioning and Diffusion in a Genetically Engineered Silk-Elastin-Like Protein Polymer Hydrogel

MACROMOLECULAR BIOSCIENCE, Issue 10 2010
Adam A. Dinerman
Abstract The influence of solute hydrophobicity and charge on partitioning and diffusion in physically crosslinked networks of a genetically engineered SELP polymer was investigated. A series of fluorescent dyes were used to assess the impact of solute charge and hydrophobicity on release behavior. The mechanism of solute release from the SELP hydrogel appeared to vary as a function of dye hydrophobicity. The extent of FITC attachment to amine-terminated G4 dendrimers influenced SELP hydrogel partitioning more than dendrimer diffusion properties. Results suggest the possibility of controlling solute release from SELP hydrogels by modifying the hydrophobicity and surface charge of drugs and drug/polymer conjugates as well as the possibility of "designing-in" solute-specific interactions. [source]

Reversible Hydrogen Storage in Hydrogel Clathrate Hydrates

ADVANCED MATERIALS, Issue 23 2009
Fabing Su
The use of inexpensive hydrogels as supports to significantly improve H2 enclathration kinetics and capacities in THF,H2O clathrate hydrate with respect to bulk solutions is demonstrated. Polymer hydrogels give rise to significant rate and capacity enhancements for hydrogen clathrate formation with respect to unmixed bulk systems, suggesting potential for accelerated gas-storage kinetics in clathrate-based technologies. [source]

Bile acid sequestrants based on cationic dextran hydrogel microspheres.

JOURNAL OF PHARMACEUTICAL SCIENCES, Issue 6 2001

Abstract Cationic dextran hydrogel microspheres with pendant quaternary ammonium groups having alkyl substituents (C2,C12) at quaternary nitrogen were synthesized. The in vitro sorption of sodium salts of four bile acids (glycocholic, cholic, taurocholic, and deoxycholic acids) with these hydrogels was studied as a function of substituent alkyl chain length and bile acid hydrophobicity. Sorption experiments were performed in phosphate buffer solutions (pH 7.4) containing one bile salt (individual sorption) or mixtures of several bile salts (competitive sorption). Parameters for individual sorption were calculated taking into consideration the stoichiometric and cooperative binding of bile salts to oppositely charged polymer hydrogels. The results show that the increase in the length of the alkyl chain of the substituent leads to an increase in both ionization constant K0 and overall stability constant of binding K, but decreases the cooperativity parameter u. The competitive sorption studies indicate that the hydrogels display a good affinity for both dihydroxylic and trihydroxylic bile salts. The molar ratio of maximum amounts bound for the two types of bile acid is 2 to 1, which is much lower than those reported for other cationic polymers recommended as bile acid sequestrants. The binding constants for the sorption of bile salts by some dextran hydrogels are 20,30 times higher than those obtained for cholestyramine under similar sorption conditions. © 2001 Wiley-Liss, Inc. and the American Pharmaceutical Association J Pharm Sci 90:681,689, 2001 [source]

Thermosensitive and Dissolution Properties in Nanocomposite Polymer Hydrogels

MACROMOLECULAR RAPID COMMUNICATIONS, Issue 17 2009
Chia-Jung Wu
Abstract We investigate the phase transition behavior and dissolution resistant properties of thermo-sensitive nanocomposite hydrogels made from PEO-PPO-PEO triblock copolymer (Pluronic F127) and Laponite silicate nanoparticles. The rapid dissolution properties of F127 copolymer hydrogels usually limit their use as sustained release drug carriers. We overcome this limitation by synergistic combination of nanoparticle gelation characteristics with polymer thermo-sensitivity. We present a proof of concept that the temperature-dependent phase transitions can be shifted as a function of hydrogel composition and that the dissolution of the polymer hydrogels as well as the release of a model drug, albumin, can be significantly slowed down by addition of nanoparticles. The dissolution resistant properties generated will prove useful in the future formulation, processing and application of our polymer hydrogels for sustained release drug delivery carriers. [source]