Polymer polyethylene glycol

Adsorption on solid matrices, which improves (at optimal protein/support ratios) enzyme dispersion, reduces diffusion limitations and favors substrate access to individual enzyme molecules. Immobilized lipases with excellent activity and stability were obtained by entrapping the enzymes in hydrophobic sol-gel materials [20]. Finally, in order to minimize substrate diffusion limitations and maximize enzyme dispersion, various approaches have been attempted to solubilize the biocatalysts in organic solvents. The most widespread method is the one based on the covalent linking of the amphiphilic polymer polyethylene glycol (PEG) to enzyme molecules [21]. 

Addition of nn-cross-linked polymers (polyethylene glycol, glycerol, snrfactants, liqnid crystals)... 

Polymers (polyethylene-glycols, polyetherurethanes, polymethyl-methacrylate (PMMA)),... 

The influence of neutral polymer polyethylene glycol and two surfactants with different charge, anionic sodium dodecylsulfate and cationic cetyltrimethylammonium bromide, on the intercalation of pre-formed Au nanoparticles into a clay matrix under ultrasonic treatment has been investigated. The polymer (surfactant) addition has been used to modify the active surface area of NaLmontmorillonite and to change the interlamellar space between the clay layers. Then, intercalated polymer (surfactant) in clay composites has been successfully replaced by Au nanoparticles under sonication. 

In this paper, the study of systems formed by Na -montmorillonite and neutral polymer, polyethylene glycol or surfactants with different chemical structure and charge, sodium dodecylsulfate (anionic) and... 

Microwave irradiation Grafting onto method Various catalysts are used [4,4 -Azobis (4-cyanovaleric acid)] Telechelic polymers, polyethylene glycol, poly-dimethyl siloxane... 

On the other hand, biomedical applications are very limited in both in vivo and in vitro conditions due to the high toxicity of these nanoparticles to the cells (You-yu et al., 2014). Therefore, nanoparticles are coated with compounds, such as natural polymers (proteins and carbohydrates) (Nair et al., 2010), synthetic organic polymers (polyethylene glycol), polyvinyl alcohol, poly-L-lactic acid. 

For proteins, alter the hydration layer surrounding the protein by (i) electrolyte addition follow the Hoffmeister series of lyotropic ions (sulfates are preferred to phosphates because of the solubility) (ii) adding hydrophilic, non-ionic polymers, polyethylene glycol (iii) adjusting the pH to shift to zpc (but avoid low pH) (iv) lower the dielectric permeability of the continuous phase by the addition of ethanol, methanol, acetone or isopropanol (v) adding flocculant polyelectrolytes (alginate, pectate, carrogcenan, CMC). 

Surface-Modified Enzymes. Enzymes acting in nearly anhydrous organic solvents always give rise to heterogeneous systems (Sect. 3.1). In order to turn them into homogeneous systems, which can be controlled more easily, proteins can be modified in order to make them soluble in lipophilic organic solvents. This can be readily achieved by covalent attachment of the amphipathic polymer polyethylene glycol (PEG) onto the surface of enzymes [460]. The pros and cons of PEG-modified enzymes are as follows [461, 462] ... 

A review is presented of the literature on the above, covering the basics of steric protection with polymers, polyethylene glycol(PEG) and other polymers for steric protection of liposomes and particles, polymer-protected... 

Figure 6.30 A process for the synthesis of an L-amino acid (leucine) from a racemic hydroxy acid (2-hydroxyisocaproate, i.e. 2-hydroxy-4-methylpentanoate). The reaction is carried out in an ultrafiltration reactor with the cofactor NAD immobilized to a soluble polymer, polyethylene glycol 20 000, so that it remains behind the ultrafiltration membrane with the enzymes...

Sirolimus is insoluble in water, having poor systemic bioavailability estimated at 18% following ingestion of the tablet. The polymers, polyethylene glycol 8000, polyethylene glycol 20000, and poloxamer 188 (a nonionic amphiphilic copolymer surfactant) augment water solubility and miscibility of SRL tablets [1]. Though SRL tablets are taken just once daily, this does not constitute an extended- or delayed-release formulation per se, as the half-life of SRL is approximately 60 hours. 

Methods The MPEG polymer (polyethylene glycol monomethyl ether, Mw approx 5000, free OH approx 0.2 mmol/g) was purified by precipitation of a DCM solution into diethyl ether. Then, the freshly precipitated polymer was dissolved in dry DCM/MeOH (50 1) and was dried by gel filtration under argon over a mixture of silica gel, magnesium sulfate, and Celite (1 0.5 1) followed by concentration under reduced pressure under argon see Note 5). 

Figure 5. Dependence of current density on hydrogen peroxide concentration for cathodes based on different peroxidases, (open circles) NaI04 treated horseradish peroxidase (closed circles) native horseradish peroxidase (open squares) lactoperoxidase (closed squares) Aithromyces ramosus. Each electrode contains approximately 10/ g osmium redox polymer, polyethylene glycol diglycidyl ether crosslinker and 1 to 4/

Gao ZN, Li JF, Wen XL (2002) Vapor pressure osmometry and its applications in the osmotic coefficients determination of the aqueous monomer glycol and polymer polyethylene glycol solutions at various temperature. Chin J Chem 20(4) 310-316... 

Generally, the amphiphilic core/shell stmcture of polymeric micelles is formed from block polymers. Polyethylene glycol (PEG) and polyethylene oxide (PEO) are often used as the hydrophilic blocks. They have been shotvn to prevent recognition by the reticuloendothelial system and increase circulation time in vivo. As in the case of liposomes and niosomes, the grafting of specific ligand molecules on the surface of the polymeric micelles allows... 

Below are quoted two examples of end-groups as they occur in polymers Polyethylene glycols ... 

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