Polyethylene glycol inclusion

Efforts should be made to stabilize an enzyme s activity. Certain agents (such as glycerol, ammonium ions, boric acid, polyethylene glycol, and even talcum powder or bentonite clay) have proven widely to be effective enzyme stabilizers. For multisubstrate enzymes, inclusion of one particular substrate with the enzyme (in the absence of other substrates or cofactors) often stabilizes an enzyme s catalytic activity. Such a substrate may also assist in unlocking the enzyme from a particularly inactive conformational form. In addition to substrates, other ligands and effectors (including reaction products. 

BritP 586224(1947) CA 41, 7120(1947) (Inclusion of 0.4% of polyethylene glycol ether contg at least 8 carbon atoms)... 

Scanning electron microscopic examination before and after dissolution and in vivo implantation show no significant changes in surface topography for the implants prepared as they are clinically used, that is, without additives. However, distinct changes in surface characteristics and the appearance of pores are evident with the inclusion of water-soluble additives such as polyethylene glycol 400. 

Research Focus Method of preparing viscoelastic polymers using crosslinked polyrotaxane inclusion complexes consisting of polyethylene glycol (PEG)-carboxyhc acid and a-cyclodextrin. 

Preparation of inclusion complex of polyethylene glycol-carboxylic acid and a-cyclodextrin... 

Nakajima et al. (1) prepared liquid crystalline polyrotaxane derivatives containing the mesogenic group 4-cyano-4 -hydroxybiphenyl attached to the a-cyclodextrin component of linear polyethylene glycol containing an a-cyclodextrin inclusion complex with an adamantane termini. 

Inclusion properties of molecular nanotubes composed of crosslinked a-cyclodextrin was investigated [47], Induced circular dichroism was used to probe the formation and dissociation of complexes between the nanotubes and azobenzene modified polyethylene glycol), either with or without a hydrophobic alkyl chain. The inclusion complex between the nanotubes and polymers formed at room temperature, and the polymers dissociated from the nanotubes with increasing temperature. 

In the inclusion compounds of such alcoholic guests with the dipeptide (2), the one-dimensional channel was not constructed, but a zero-dimensional pocket-type cavity was formed. Therefore, we wondered whether polyethylene glycol)s (PEG)... 

Akazome, M., Takahashi, T., Sonobe, R., and Ogura, K. (2001) Inclusion of polyethylene glycol)s by crystalline (R)-(l-naphthyl)glycyl-(i )-phenylglycine, Supramolecular Chem. 13, 109-136. 

Recently a CD-insulin complex was encapsulated in polymethacrylic acid-chi-tosan-polyether[polyethylene glycol (PEG)-propylene glycol] copolymer PMCP nanoparticles from the free-radical polymerization of methacrylic acid in the presence of chitosan and polyether in a medium free of solvents or surfactants. Particles had a size distribution of 500-800 nm. The HP-B-CD inclusion complex with insulin was encapsulated into the nanoparticles, resulting in a pH-dependent release profile as seen in Figure 2. The biological activity of insulin was demonstrated with enzyme-... 

Singh et all studied the interaction of various barbiturates with polyethylene glycol 4000 and found that phe-nobarbital formed a complex with the glycol. The solubility of the complexed phenobarbital was much lower than the intrinsic solubility of phenobarbital in the absence of polyethylene glycol 4000. Utilizing the everted sac technique to measure the rate of intestinal permeability, they found that the decreased solubility greatly decreased the rate of permeation. The other three barbiturates studied, pentobarbital, barbital, and barbituric acid, did not interact with the polyethylene glycol 4000 and the inclusion of this material did not decrease their rates of intestinal permeation. 

Immobilization through inclusion into a gel, similarly to immobilization by adsorption, is a physical method of protein fixation. Advantages of such a method are its simplicity and the absence of chemical modification of the enzyme molecules. Polyacrylamide, polyethylene glycol methacrylate, polysaccharide, polyionite, as well as various inorganic gels are used. 

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