Polyethylene glycol copolymers

VandeVondele S, Voros J, Hubbell JA (2003) Rgd-grafted poly-l-lysine-graft- (polyethylene glycol) copolymers block non-specific protein adsorption while promoting cell adhesion. Biotechnol Bioeng 82 784—790... 

Materials that typify thermoresponsive behavior are polyethylene- polyethylene glycol) copolymers that are used to fiinchonalize the surfaces of polyethylene films (smart surfaces). When the copolymer is immersed in water, the poly(elhylene glycol) functionalities at the surfaces have solvation behavior similar to poly(ethylene glycol) itself. The ability to design a smart surface in these cases is based on the observed behavior of inverse temperature-dependent solubility of poly(alkene oxidejs in water. 

Kalivoda et al. in 2012 studied the use of blends of different polymeric carriers to enhance the dissolution rate of the poorly water-soluble model drug fenofibrate via HME technology. Copovidone (COP), polyvinyl caprolactam-polyvinyl acetate-polyethylene glycol copolymer (PVCL-PVAc-PEG) and hypromellose 2910/5 (HPMC) were used as a polymeric carriers. Hot-melt extruded feno-flbrate was evaluated by DSC and x-ray diffractometry. Dissolution studies showed that there was a significant increase in the dissolution rate of the hot-melt extruded fenofibrate compared to the pure drug or physical mixture of drug and polymeric carriers. These researchers reported that the fenofibrate extrudates exhibited a 7.6- to 12.1-fold supersaturation and provided superior dissolution performance than marketed formulations Lipidil and Lipidil -Ter. 

Polyvinyl alcohol-polyethylene glycol copolymer Kollicoat IR 45 208... 

Recent work on crystallinity measurements is reported below sulfur containing ether ketones [14], polyethylene glycol [15], polystyrene (PS) [16, 17], (PC) [18], polyphenylene alkene diyls [19, 20], isotactic polypropylene [20, 21], polyethylene [21, 22], polyimide [23], poly(2,5 bis (4-methoxyphenyl) oxycarbonyl styrene [24], polyazomethine esters [25], PET-polybutylene terephthalate blends [26], polycyclohexyl ethylene copolymers [27], polycaprolactone [28], syndiotactic polystyrene [29, 30], polyvinylidene fluoride-trifluorethylene copolymer [30], polyethers [31], isotactic methyl methacrylate [32], soy protein isolate polymers [33], polyamide 6/66 [34], polytrimethylene-2,6-naphthalate [35, 36], PE like polyesters [37], polycyclohexadiene [38], p-dioxolone, L-lactide - polyethylene glycol copolymers [39], ethylene - methacrylic acid copolymers and ionomers [40]. 

Figure 2.3 Schematic diagram of CRLXIOI [8], a linear cyclodextrin-polyethylene glycol copolymer conjugated with camptothecin (CPT). Reproduced with permission from J. Cheng, K.T. Khin, and M.E. Davis, Molecular Pharmaceutics,...

Most of the commercial polymers consist of polyether blocks separated by polyamide blocks. The polyether blocks may be based on polyethylene glycol, polypropylene glycol or, more commonly, polytetramethylene ether glycol. The polyamides are usually based on nylon 11 but may be based on nylons 6 or 66 even a copolymer, e.g. 6/11. 

Polymers such as the acrylic PVM/MA copolymer are added to prevent bacteria from breaking down pyrophosphates. Other long polymers used are polyethylene glycol (PEG) in various weights (PEG-6, PEG-8, PEG-40, etc.), and polypropylene glycol (PPG). 

A series of poly(ester-urethane) urea triblock copolymers have been synthesized and characterized by Wagner et al/ using PCL, polyethylene glycol, and 1,4 diisocyanatobutane with either lysine ethyl ester or putrescine, as the chain extender. These materials have shown the elongation at break from 325% to 560% and tensile strengths from 8 to 20 MPa. Degradation products of this kind of materials did not show any toxicity on cells. 

The anionic method of polymerization is most useful for the synthesis of low molecular weight hydroxy-terminated oligomers and polymers that are to be further processed. For example, the treatment of hydroxy-terminated oligomers with isocyanates has been used to obtain polyester-urethanes (9,20), while triblock copolymers (PCL-PEG-PCL) are prepared by initiating the polymerization of e-caprolactone with the disodium alcoholate from polyethylene glycol (26). 

II. B polyethylene glycol, ethylene oxide, polystyrene, diisocyanates (urethanes), polyvinylchloride, chloroprene, THF, diglycolide, dilac-tide, <5-valerolactone, substituted e-caprolactones, 4-vinyl anisole, styrene, methyl methacrylate, and vinyl acetate. In addition to these species, many copolymers have been prepared from oligomers of PCL. In particular, a variety of polyester-urethanes have been synthesized from hydroxy-terminated PCL, some of which have achieved commercial status (9). Graft copolymers with acrylic acid, acrylonitrile, and styrene have been prepared using PCL as the backbone polymer (60). 

Carboxymethylcellulose, polyethylene glycol Combination of a cellulose ether with clay Amide-modified carboxyl-containing polysaccharide Sodium aluminate and magnesium oxide Thermally stable hydroxyethylcellulose 30% ammonium or sodium thiosulfate and 20% hydroxyethylcellulose (HEC) Acrylic acid copolymer and oxyalkylene with hydrophobic group Copolymers acrylamide-acrylate and vinyl sulfonate-vinylamide Cationic polygalactomannans and anionic xanthan gum Copolymer from vinyl urethanes and acrylic acid or alkyl acrylates 2-Nitroalkyl ether-modified starch Polymer of glucuronic acid... 

Ethoxylated methylcarboxylates Propoxyethoxy glyceryl sulfonate Alkylpropoxyethoxy sulfate as surfactant, xanthan, and a copolymer of acrylamide and sodium 2-acrylamido-2-methylpropane sulfonate Carboxymethylated ethoxylated surfactants (CME) Polyethylene oxide (PEG) as a sacrificial adsorbate Polyethylene glycols, propoxylated/ethoxylated alkyl sulfates Mixtures of sulfonates and nonionic alcohols Combination of lignosulfonates and fatty amines Alkyl xylene sulfonates, polyethoxylated alkyl phenols, octaethylene glycol mono n-decyl ether, and tetradecyl trimethyl ammonium chloride Anionic sodium dodecyl sulfate (SDS), cationic tetradecyl trimethyl ammonium chloride (TTAC), nonionic pentadecylethoxylated nonylphenol (NP-15), and nonionic octaethylene glycol N-dodecyl ether Dimethylalkylamine oxides as cosurfactants and viscosifiers (N-Dodecyl)trimethylammonium bromide Petrochemical sulfonate and propane sulfonate of an ethoxylated alcohol or phenol Petrochemical sulfonate and a-olefin sulfonate... 

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,... 

Fused silica capillary columns of various internal bores and of lengths in the range 25 to 50 m are mainly employed for analytical separations. A variety of polar and non-polar column types are available including those open tubular types with simple wall coatings (WCOT), those with coatings dispersed on porous solid-supports to increase adsorbent surface area (SCOT) and porous layer open tubular (PLOT) columns. Important stationary phases include polyethylene glycol, dimethylpolysiloxane and different siloxane copolymers. Various sample introduction procedures are employed including ... 

If mono-hydroxyl functionalized polyethylene glycol), HO-PEG, is added to Ca(NTMS2)2.THF2, then addition of LA affords the diblock PEG-b-PLA (Mn= 15,500, Mn calc = 15,500, Mw/Mn = 1.03).832 Using a similar strategy the reaction of CaFI2 with telechelic diol HO-(PEG)-OH, followed by polymerization of L-LA results in a triblock structure, PLA-b-PEG-b-PLA of narrow polydispersity (1.02-1.08).835 836 Triblock copolymers of morpholine-2,5-diones with PEO have also been prepared in this manner.837... 

It should be pointed out that the addition of substances, which could improve the biocompatibility of sol-gel processing and the functional characteristics of the silica matrix, is practiced rather widely. Polyethylene glycol) is one of such additives [110— 113]. Enzyme stabilization was favored by formation of polyelectrolyte complexes with polymers. For example, an increase in the lactate oxidase and glycolate oxidase activity and lifetime took place when they were combined with poly(N-vinylimida-zole) and poly(ethyleneimine), respectively, prior to their immobilization [87,114]. To improve the functional efficiency of entrapped horseradish peroxidase, a graft copolymer of polyvinylimidazole and polyvinylpyridine was added [115,116]. As shown in Refs. [117,118], the denaturation of calcium-binding proteins, cod III parvalbumin and oncomodulin, in the course of sol-gel processing could be decreased by complexation with calcium cations. 

Knorr V, Ogris M, Wagner E (2008) An acid sensitive ketal-based polyethylene glycol-oligoethylenimine copolymer mediates improved transfection efficiency at reduced toxicity. Pharm Res 25 2937-2945... 

Nathan, A., Zalipsky, S., Ertel, S.I., Agathos, S.N., Yarmush, M.L., and Kohn, J. (1993) Copolymers of lysine and polyethylene glycol A new family of functionalized drug carriers. Bioconjugate Chem. 4, 54-62. 

Bioerodible polymers offer a unique combination of properties that can be tailored to suit nearly any controlled drug delivery application. By far the most common bioerodible polymers employed for biomedical applications are polyesters and polyethers (e.g., polyethylene glycol), polylactide, polyglycolide and their copolymers). These polymers are biocompatible, have good mechanical properties, and have been used in... 

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