Binding characteristics between polyethylene glycol (PEG) and proteins in aqueous solution.

Preferential hydration and solubility of proteins in aqueous solutions of polyethylene glycol

An ecological new approach for treating Cr(VI)-containing industrial wastewater: Photochemical reduction

Synthesis, characterization and performance of asymmetric polyethersulfone (PES) ultrafiltration membranes with polyethylene glycol of different molecular weights as additives

BackgroundBiodegradable polymers are commonly used as dermal fillers in plastic surgery. Among these, poly-L-lactic acid (PLLA) distinguishes itself owing to its good biocompatibility, degradability, and ability to act as a collagen stimulator.ObjectivesIn this study, the differential behavior of PLLA microspheres with varying microscopic morphology and surface hydrophilicity was investigated both in vitro and in vivo.MethodsThe introduction of short hydrophilic polyethylene glycol (PEG) chains into the PLLA molecule was employed to modify the morphology and enhance the surface hydrophilicity of the microspheres. The morphology and physicochemical properties of the PLLA and PLLA-b-PEG microspheres were characterized. Irregular PLLA particles, PLLA, and PLLA-b-PEG microspheres were implanted into the subcutaneous tissue of rabbit models, and at 4, 26, and 52 weeks after implantation, biopsy samples were collected for hematoxylin and eosin and Masson’s trichrome staining to evaluate differences in the tissue response between different implants.ResultsThe results of in vitro research demonstrated that while the addition of short-chain hydrophilic PEG afforded a smoother surface for the microspheres, it had no significant effect on the molecular weight and degradation rate of PLLA. The histological examination revealed that the PLLA-b-PEG microspheres exhibited enhanced biocompatibility compared with the pure PLLA microspheres, while the irregular PLLA particles showed the highest inflammatory response among the 3 materials.ConclusionsIn this study, we found that the properties of PLLA were improved upon modification by short-chain PEG without reducing the collagen regeneration ability, thereby affording a better histocompatibility.Level of Evidence: 5 (Therapeutic)

Allergy evaluation of messenger RNA vaccine reactions is crucial, with a specific role for polyethylene glycol testing

Effect of polyethylene glycol (PEG) chain organization on the physicochemical properties of poly( d, l-lactide) (PLA) based nanoparticles

Copolymer membranes prepared by bulk copolymerization of polyethylene glycol dimethacrylates of three different degrees of polymerization as macromonomer and benzyl methacrylate as comonomer were used for the separation of aqueous ethanol solutions in both pervaporation and evapomeation. The copolymer membranes preferentially permeated water from an aqueous ethanol solution in evapomeation. In pervaporation, ethanol was predominantly permeated from an aqueous ethanol solution through the copolymer membranes containing a long polyethylene glycol (PEG) chain above about 20 wt% PEG content in a copolymer. This result was attributed to a remarkable swelling of the copolymer membrane containing a long PEG chain by the aqueous ethanol solution in pervaporation. In evapomeation, both the separation factors and the permeation rates through these membranes are not much affected by the ethanol concentration in the feed vapor. In pervaporation, they were significantly dependent on the ethanol concentration ...

The purpose of the present study was to investigate the effect of polyethylene glycol (PEG) molecular weights (6000, 12000 and 20000) as solid dispersion (SD) carriers on the dissolution behavior of simvastatin. SDs with various drug : carrier ratios were prepared by solvent method and evaluated for dissolution rate. Differential scanning calorimetry (DSC), X-ray diffraction (XRD), infrared spectroscopy and solubility studies were also performed on the optimum SD formulation. Samples prepared with all three types of PEG showed improved drug dissolution compared to intact drug and corresponding physical mixtures. Meanwhile, the best result was obtained by PEG 12000 with drug : carrier ratio of 1:7 which showed a 3-fold increase in dissolution rate compared to the intact drug. Based on DSC and XRD, no crystalline change occurred during the sample preparation. Solubility studies revealed that increasing the PEG molecular weight resulted in higher phase solubility of drug. In addition, saturated solubility of the optimum SD was significantly higher than that of intact drug and the related physical mixture (24.83, 8.74 and 8.88 μg/mL, respectively) that could be due to the decreased particle size and aggregation. The results confirmed the influence of PEG molecular weight on drug dissolution rate from solid dispersion systems.

The four cysteine proteinases, papain, chymopapain, caricain, and endoproteinase Gly-C were isolated and purified as the catalytically competent species from the commercially available latex of the tropical treeCarica papaya L. Their free thiol function (cysteine-25), which is essential for activity, was protected in the form of a mixed disulfide containing a 5 kDa polyethylene glycol (PEG) chain. The second (nonessential) free thiol function (cysteine-117) of chymopapain was blocked similarly. Caricain was also derivatized through acylation of its amino functions by PEG chains (average: 15 moles of PEG per mole of enzyme). The Chromatographic behavior of these conjugates was examined on ion-exchange and hydrophobic gels and compared to the Chromatographic behavior of the unpegylated proteinases. The results indicated that charge-shielding effects by PEG chain(s), surrounding the different proteinases, plays(play) a key role in the course of separation of pegylated and unpegylated species by ion-exchange chromatography. Similarly, PEG chain(s) is(are) able to mask hydrophobic regions on the surface of the proteinases. However, the affinity showed by PEG itself for the hydrophobic ligands immobilized on the matrix is the preponderant factor determining the behavior of the PEG-proteinases conjugates on Fractogel TSKButyl-650.

Polyethylene glycol (PEG) is a preferred hydrophilic polymer as an additive for casting solutions. In this study, polymeric membranes containing 1,10-phenanthroline and different molecular weights of polyethylene glycol (PEG) are tested for the morphological change and metal retention on the membrane surface. Additives in the form of PEGs with molecular weights of 400 Da, 600 Da, and 6000 Da were used. The morphology of each membrane was examined using scanning electron microscopy (SEM). It appears that copper has more retention than cadmium in all membrane components in SEM–EDS analysis. FTIR spectra findings provided evidence that PEG binds to the PVC backbone through hydrogen bonds involving chlorine atoms in the PVC and hydrogen atoms in the hydroxyl groups of PEG. The porosity of the membrane was determined by gravimetric method. The molecular weight of PEG in the membrane seems to be increasing, the porosity of the membrane improved. The porosity of the membrane obtained with PVC/ PEG/ 1,10-phenanthroline is 62.85 for PEG 400, 80.00 for PEG 600 and 83.50 for PEG 6000. The order of metal retention on the surface of the membranes consisting of PVC-1,10 phenanthroline and PEGs are Cu > Cd, indicating that with its large diameter (140 pm), cadmium cannot settle into the pores as much as copper. Except for PEG 600, the retention of both metals decreased with the addition of phenanthroline to the membrane containing PEG. The amorphous structure was detected from the XRD of the membranes. Thermal analysis of the membrane was determined by TG-DSC.Graphical

Effect of molecular weight of PEG on membrane morphology and transport properties

Polyethylene glycol hypersensitivity, patient outcomes in a 7-year retrospective study

Synthesis and characterization of a novel alginate–poly(ethylene glycol) graft copolymer

The interaction of water within synthetic and natural hydrogel systems is of fundamental importance in biomaterial science. A systematic study is presented on the swelling behavior and states of water for a polyethylene glycol-diacrylate (PEGDA)-based model neutral hydrogel system that goes beyond previous studies reported in the literature. Hydrogels with different network structures are crosslinked and swollen in different combinations of water and phosphate-buffered saline (PBS). Network variables, polyethylene glycol (PEG) molecular weight (MW), and weight fraction are positively correlated with swelling ratio, while “non-freezable bound water” content decreases with PEG MW. The presence of ions has the greatest influence on equilibrium water and “freezable” and “non-freezable” water, with all hydrogel formulations showing a decreased swelling ratio and increased bound water as ionic strength increases. Similarly, the number of “non-freezable bound water” molecules, calculated from DSC data, is greatest—up to six molecules per PEG repeat unit—for gels swollen in PBS. Fundamentally, the balance of osmotic pressure and non-covalent bonding is a major factor within the molecular structure of the hydrogel system. The proposed model explains the dynamic interaction of water within hydrogels in an osmotic environment. This study will point toward a better understanding of the molecular nature of the water interface in hydrogels.

The molecular structures of polyethylene glycol (PEG) and chitosan (CS) are illustrated as follows: 1 CS 2 PEG The intermolecular interactions between these two polymers were studied by viscometry with a thermodynamic parameter α, which was first proposed by Sun et al. The weight additive rule of the intrinsic viscosity of polyblend relating to the values of each polymeric constituent was attested to with PEG/CS polyblend. The calculation formula of Huggins coefficient for polyblend, km, was theoretically deduced, and a very simple expression of α was obtained. First, the values of α for PEG/CS blends with different PEG molecular weight were estimated from the experimental viscosity data of the polyblends with different mixed ratio. According to these values of α, it can be predicted that an attractive interaction exists between the molecule of PEG and that of CS. Second, the viscosity of CS was measured in pseudo-solvents (PEG dissolved in 0.01N sodium chloride aqueous solution) with different PEG concentrations. From these viscosity data, the values of cross Huggins coefficient are calculated to be all larger than the values of the Huggins coefficient both for CS and for PEG. On the revised α criterion, the dissimilar molecular interaction in PEG/CS polyblend is demonstrated to be attractive too. © 1998 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 36: 1275–1281, 1998