Interactions of phospholipid- and poly(ethylene glycol)-modified surfaces with biological systems: relation to physico-chemical properties and mechanisms

The presence of poly(ethylene glycol) (PEG) at the surface of a liposomal carrier has been clearly shown to extend the circulation lifetime of the vehicle. To this point, the extended circulation lifetime that the polymer affords has been attributed to the reduction or prevention of protein adsorption. However, there is little evidence that the presence of PEG at the surface of a vehicle actually reduces total serum protein binding. In this review we examine all aspects of PEG in order to gain a better understanding of how the polymer fulfills its biological role. The physical and chemical properties of the polymer are explored and compared to properties of other hydrophilic polymers. An evidence based assessment of several in vitro protein binding studies as well as in vivo pharmacokinetics studies involving PEG is included. The ability of PEG to prevent the self-aggregation of liposomes is considered as a possible means by which it extends circulation longevity. Also, a “dysopsonization” phenomenon where PEG actually promotes binding of certain proteins that then mask the vehicle is discussed.

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Poly(ethylene glycol) Diacrylate Iongel Membranes Reinforced with Nanoclays for CO2 Separation

Membranes ◽

10.3390/membranes11120998 ◽

2021 ◽

Vol 11 (12) ◽

pp. 998

Author(s):

Ana R. Nabais ◽

Rute O. Francisco ◽

Vítor D. Alves ◽

Luísa A. Neves ◽

Liliana C. Tomé

Keyword(s):

Ethylene Glycol ◽

Gas Separation ◽

Mechanical Stability ◽

Chemical Properties ◽

Ideal Gas ◽

Gas Permeation ◽

Poly Ethylene Glycol ◽

One Pot ◽

Glycol Diacrylate ◽

Poly Ethylene

Despite the fact that iongels are very attractive materials for gas separation membranes, they often show mechanical stability issues mainly due to the high ionic liquid (IL) content (≥60 wt%) needed to achieve high gas separation performances. This work investigates a strategy to improve the mechanical properties of iongel membranes, which consists in the incorporation of montmorillonite (MMT) nanoclay, from 0.2 to 7.5 wt%, into a cross-linked poly(ethylene glycol) diacrylate (PEGDA) network containing 60 wt% of the IL 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([C2mim][TFSI]). The iongels were prepared by a simple one-pot method using ultraviolet (UV) initiated polymerization of poly(ethylene glycol) diacrylate (PEGDA) and characterized by several techniques to assess their physico-chemical properties. The thermal stability of the iongels was influenced by the addition of higher MMT contents (>5 wt%). It was possible to improve both puncture strength and elongation at break with MMT contents up to 1 wt%. Furthermore, the highest ideal gas selectivities were achieved for iongels containing 0.5 wt% MMT, while the highest CO2 permeability was observed at 7.5 wt% MMT content, due to an increase in diffusivity. Remarkably, this strategy allowed for the preparation and gas permeation of self-standing iongel containing 80 wt% IL, which had not been possible up until now.

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Thermo-responsive polyurethane hydrogels based on poly(ethylene glycol) and poly(caprolactone): Physico-chemical and mechanical properties

Journal of Applied Polymer Science ◽

10.1002/app.43573 ◽

2016 ◽

Vol 133 (25) ◽

Cited By ~ 10

Author(s):

Lucas Polo Fonseca ◽

Rafael Bergamo Trinca ◽

Maria Isabel Felisberti

Keyword(s):

Mechanical Properties ◽

Ethylene Glycol ◽

Poly Ethylene Glycol ◽

Physico Chemical ◽

Poly Ethylene ◽

Poly Caprolactone

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Effects of Poly(Ethylene Glycol) Segment on Physical and Chemical Properties of Poly(Ether Ester) Elastomers

Materials Science Forum ◽

10.4028/www.scientific.net/msf.898.2147 ◽

2017 ◽

Vol 898 ◽

pp. 2147-2157 ◽

Cited By ~ 2

Author(s):

Qiu Shu Xu ◽

Lian Tang ◽

Chao Sheng Wang ◽

Biao Wang ◽

Hua Ping Wang

Keyword(s):

Molecular Weight ◽

Ethylene Glycol ◽

Impact Resistance ◽

Chemical Properties ◽

Weight Ratio ◽

Soxhlet Extraction ◽

Polymerization Process ◽

Poly Ethylene Glycol ◽

Poly Ethylene ◽

Ether Ester

Poly (ether ester) elastomer, a segmented copolymer, recently has attracted a wide attention for its unique properties such as elasticity, low temperature impact resistance and chemistry resistance. In this work, a range of poly (ether ester) s were synthesized via a two-step polymerization method using poly (ethylene terephthalate) (PET) as rigid segment and poly (ethylene glycol) (PEG) as flexible segment. The effects of the molecular weight (1000-8000 g/mol) and the weight ratios with PEG (30/100-70/100) of PET segments on the performance of synthetic copolymers were investigated. The chemical structure, thermal properties and hydrophilic performance of the copolymers were respectively characterized. Additionally, the practical block ratios of PEG/PET were calculated by the 1H-NMR Spectra of the copolymer after Soxhlet extraction. Through the obtained results, it revealed that increasing the molecular weight or content of PEG could enhance the hydrophilic performance of the copolymers and reversely reduce its thermal stability. It was shown that the reactivity of PEG in the polymerization process was weakened when its molecular weight was above 4000 or weight ratio with PTA was higher than 60/100, subsequently affected the practical block ratios of PEG/PET in the resulting poly(ether ester)elastomers.

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