Polyethylene glycol linear

Schaffert D, Kiss M, Rodl W, Shir A, Levitzki A, Ogris M, Wagner E (2011) Poly(I C)-mediated tumor growth suppression in EGF-receptor overexpressing tumors using EGF-polyethylene glycol-linear polyethylenimine as carrier. Pharm Res 28 731-741... 

Polyethylene glycol (PEG) consists of repeating units of ethylene glycol forming linear or branched polymers with different molecular masses. Pegylation is the process by which PEG chains are covalently attached to lEN molecules. Pegylation confers a number of properties on lEN-a molecules, such as sustained blood levels that enhance antiviral effectiveness and reduce adverse reactions, as well as a longer half-life and improved patient compliance (Kozlowski et al. 2001). 

In the previously described electrophoretic methods, the capillary was filled with electrolytes only. Another mode of operation in capillary electrophoresis involves filling the capillary with gel or viscous polymer solutions. If desired, a column can be packed with particles and equipped with a frit.68 This mode of analysis has been favorably used for the size determination of biologically important polymers, such as DNA, proteins, and polysaccharides. The most frequently used polymers in capillary gel electrophoresis are cross-linked or linear polyacrylamide,69 cellulose derivatives,70-75 agarose,76 78 and polyethylene glycols. 

In their efforts to construct stimuli-responsive, supramolecular amphiphiles, Frechet et al. [126-129] reported the synthesis of a novel series of AB and ABA block copolymers via the Williamson ether synthesis (e.g., 47, Fig. 21). Polyethylene glycols (PEGs) of different lengths were used as the linear hydrophilic B block while polyaryl ether dendrons of different sizes were used as the hydro-phobic A block. These copolymers were characterized by optical microscopy,... 

Antipina et al. (1972) also investigated the complexation of polyethylene glycols) with linear polymethacrylic and acrylic acids of molecular... 

The FT-Raman spectra of a range of drugs (theophylline, indomethacin, diclofenac, and promethazine) in several polymers (sodium alginate, hydroxy-propylmethylcellulose, and polyethylene glycol) have been obtained [56,57]. In these studies, the linearity of response of Raman scattering to species concentration was exploited to analyze diclofenac at concentrations of 0.01-6.0% w/w... 

Fig. 4.9. Dependence of resolution on analyzer pressure linear MALDI-TOF spectra of polyethylene glycol 400 recorded at a pressure of 4 x lO" Pa (left) and 5 x 10 Pa (right). Adapted from Ref. [40] with permission. John Wiley Sons, 1994.

Typically, the liquid permeabilities are obtained with water being the permeate and expressed in terms of L/h-m -bar. The gas permeabilities are often expressed in terms of air or nitrogen permeabilities. The retention characteristics can be generally and generically obtained by using some model molecules. The most commonly used model molecules are polyethylene glycol (PEG) polymers which are linear and flexible in nature, and... 

Aqueous SEC Experiments. Aqueous SEC separations were carried out at ambient temperature using two column sets of MicroPak TSK PW Type gel which were investigated for linearity of molecular weight calibration curve using polyethylene glycol (PEG) and polyethylene oxide (PEO) narrow MWD standards. Columns were matched in pore volume as closely as possible to promote linearity of the molecular weight calibration cuiA e. Column set A consisted... 

Macrogol is also an osmotic laxative. Macrogol 4000 is a long linear polymer, also known as polyethylene glycol. It is not absorbed from the gut into the bloodstream, but remains in the gut where it causes water to be drawn into the lower bowel. Anaphylaxis to macrogol has been described. 

The influence of the structure of the main chain on the chymotrypsin catalyzed release of p-nitroaniline is shown in Fig. 15. Oligopeptide p-nitroanili-des were attached to HPMA copolymers (as side-chains) and to polyethylene glycol (end-point attachment). From the values of kcat/KM it is evident that all oligopeptide p-nitroanilides attached to PEG were cleaved faster than those attached to HPMA copolymers. It appeared that the PEG substrates fit better into the active site of chymotrypsin due to the linearity and flexibility of the PEG molecule, and the type of spacer attachments [255]. 

Indeed, at very high polymer concentrations enhancement of these effects occurs. Recent studies by Franks et al. 23) on the rheological behaviour and freeze fracture electron microscopical analysis of several synthetic linear flexible polymers, including poly(vinylpyrrolidone) and polyethylene glycol) in concentrated solutions, suggest that these molecules do not form a network mesh but rather exhibit aggregation. Anionic polysaccharides, on the other hand, are known to form an anisotropic packing array in condensed films. These films may be stretched to enhance orientation and be used for X-ray diffraction studies... 

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. 

Cyanuric chloride was used by Okumura et al. (2) to crosslink the a-cyclodex-trin portion of linear polyethylene glycol polyrotaxane containing an ethylene amine termini. 

Although these peak areas were sufficient to quantify quinaldic acid on Carbowax columns, residual water present in the extracts of the ion-exchange resins interfered in previous experiments using water-sensitive polydimethylsiloxane stationary phases. The change to a polyethylene glycol stationary phase eliminated the water interferences, and good linear calibration curves for methyl quinaldate were then obtained. 

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