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The carbon dioxide (CO2) separation technology has become a focus recently, and a developed example is the membrane technology. It is an alternative form of enhanced gas separation performance above the Robeson upper bound line resulting in the idea of mixed matrix membranes (MMMs). With attention given to membrane technologies, the MMMs were fabricated to have the most desirable gas separation performance. In this work, blend MMMs were synthesised by using two polymers, namely, poly(ether sulfone) (PES) and poly (ethylene glycol) (PEG). These polymers were dissolved in blend N-methyl-2-pyrrolidone (NMP) and dimethylformamide (DMF) solvents with the functionalised multi-walled carbon nanotubes (MWCNTs-F) fillers by using the mixing solution method. The embedding of the pristine MWCNTs and MWCNTs-F within the new synthesised MMM was then studied towards CO2/N2 separation. In addition, the optimisation of the loading of MWCNTs-F for blend MMM for CO2/N2 separation was also studied. The experimental results showed that the functionalised MWCNTs (MWCNTs-F) were a better choice at enhancing gas separation compared to the pristine MWCNTs (MWCNTs-P). Additionally, the effects of MWCNTs-F at loadings 0.01 to 0.05% were studied along with the polymer compositions for PES:PEG of 10:20, 20:20 and 30:10. Both these parameters of study affect the manner of gas separation performance in the blend MMMs. Overall, the best performing membrane showed a selectivity value of 1.01 + 0.05 for a blend MMM (MMM-0.03F) fabricated with 20 wt% of PES, 20 wt% of PEG and 0.03 wt% of MWCNTs-F. The MMM-0.03F was able to withstand a pressure of 2 bar, illustrating its mechanical strength and ability to be used in the post combustion carbon capture application industries where the flue gas pressure is at 1.01 bar. [ABSTRACT FROM AUTHOR]

In this study, bionanocomposite films based on poly(lactide) (PLA) plasticised with poly(ethylene glycol) (PEG) (7.5 wt%) and reinforced with various contents of nanofibrillated cellulose (NFC) (1, 3, 5 wt%) were prepared. The hydrothermal degradation was investigated through immersion in several aqueous environments at temperatures of 8, 23, 58, and 70 °C as a function of time (7, 15, 30, 60, 90 days). The effect of water immersion on the physicochemical properties of the materials was assessed by monitoring the changes in the morphology, thermo-oxidative stability, thermal properties, and molar mass through field emission scanning electron microscopy (FE-SEM), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and gel permeation chromatography (GPC). The hydrothermal degradation behaviour was not critically affected regardless of the nanofibrillated cellulose content. All the materials revealed certain integrity towards water immersion and hydrolysis effects at low temperatures (8 and 23 °C). The low hydrothermal degradation may be an advantage for using these PLA biocomposites in contact with water at ambient temperatures and limited exposure times. On the other hand, immersion in water at higher temperatures above the glass transition (58 and 70 °C), leads to a drastic deterioration of the properties of these PLA-based materials, in particular to the reduction of the molar mass and the disintegration into small pieces. This hydrothermal degradation behaviour can be considered a feasible option for the waste management of PLA/PEG/NFC bionanocomposites by deposition in hot aqueous environments. [ABSTRACT FROM AUTHOR]

Poly(lactic acid)-poly(ethylene glycol) with Boc-glycine linked copolymer was synthesized from lactic acid, poly(ethylene glycol), and Boc-glycine. The synthesized polymers were characterized by thermogravimetric analysis, differential scanning calorimetry, IR, and NMR spectroscopic techniques. Drug release, stability, and anti-inflammatory studies were conducted in vitro. This targeted polymer may be used in medical applications as a potential drug carrier. [ABSTRACT FROM AUTHOR]

Produced via electrospinning, polyurethane (PU) scaffolds have always attracted the interest of medical applications due of their unique properties such as good adhesion, biocompatibility and excellent mechanical strength. However, the poor hydrophilicity and hemocompatibility of PU presented a problem during PU's application in the manufacturing of biomedical materials. We hypothesized that the incorporation of polyethylene glycol (PEG) and phosphatidylcholine (PC) into electrospinning solution of PU could improve the cell affinity and hemocompatibility. This research focused on fabricating hybrid PU-PEG and PU-PC random/aligned scaffolds through electrospinning technique and comparing their properties as a potential biocompatible scaffold for vascular tissue engineering. PC was doped into a PU solution in order to prepare an electrospun scaffold through the electrospinning technology while crosslinked electrospun PUPEG hybrid scaffolds were fabricated by photoinduced polymerization. The contact angle dramatically decreased from 122.3±0.8° to 39.1±0.8° with doping of PC in electrospinning solution while it decreased from 122.3±0.8° to 41.6±0.8° with doping of PEG. Furthermore, the mechanical properties of PU scaffolds were altered significantly by the addition of PC. The hemolysis and cytocompatibility assays demonstrated that these composite scaffolds could potentially be used as a smalldiameter vascular graft. [ABSTRACT FROM AUTHOR]

Immobilization of bioanalytes (e.g., protein, lipid membrane, and cells) within a microfludic channel is a useful strategy in diverse biological analysis including biosensor, diagnosis, and biochemical reactions. Such microfluidic systems can offer miniaturized platforms with distinct advantages such as reduced use of samples or reagents and increased resolution. In particular, polymeric microfluidic devices (e.g., polydimethylsiloxane (PDMS)) bound to a substrate have been widely used. However the non-specific adsorption of bioanalytes is serious problem for microfluidic biological assays, especially for dilute samples. To overcome such limitations, a simple and widely applicable microfluidic channels combined with polyethylene glycol (PEG) microwells have been developed. In this review, we summarize the methods and application of PEG microwells with a particular emphasis on integrated microfluidic systems. The assembly between PEG microwell and microchannel enables precise delivery and manipulation of the biosamples, leading to development of miniaturized diagnostic assays, microreactors, and multiple screening platforms for tissue engineering and cell biology. [ABSTRACT FROM AUTHOR]

Polyethylene terephthalate/poly(ethylene glycol)/2, 6-naphthalene dicarboxylate (PET/PEG/NDC) copolymers were synthesized and characterized. The results demonstrated that T dramatically decreased-by approximately 20 °C-when 8 wt.% PEG was added to neat PET. However, T slightly increased-by around 6 °C-from the reduced value, when a third ingredient, NDC, was incorporated. The melting temperature T and fusion enthalpy △ H decreased when the 8 wt.% PEG was copolymerized. Further incorporation of NDC into the PET/8 % PEG copolymer, after a small initial increase in T and △ H for PET/8 % PEG/2.3 % NDC, caused substantially reduce in both properties for PET/8 % PEG/9.2 % NDC. A mechanical test revealed that PET/8 % PEG/NDC copolymers maintained high mechanical integrity until degradation, verifying that the inclusion of NDC enhances the weatherability of PET/PEG copolymer. The rheological Cole-Cole plots indicated the occurrence of phase separation in PET/PEG melt, but the incorporation of NDC suppressed this incompatibility. The biodegradation results indicated that the degradation comprised two stages-a period of rapid degradation, which was associated with the hydrolysis of PEG segments, and a period of slow degradation, which was caused by erosion of the short aliphatic segments by the microbes. [ABSTRACT FROM AUTHOR]

A novel thermosensitive block copolymer composed of poly(ethylene glycol) (PEG) and poly( N-( N-Boc-ethylenediamine)methacryloylglycylglycylamide) (PBEMAGG) with pendant amino groups was synthesized via reversible addition-fragmentation chain transfer (RAFT) polymerization. The thermosensitivity of these copolymers was studied with varying temperatures and block lengths of copolymers. The results indicated that the lowest critical solution temperatures (LCST) of this thermosensitive copolymer cover the range from 20 °C up to near 45 °C, and can be easily and precisely regulated by changing the block length or the amount of pendant amino groups. This copolymer with well-controlled LCST and pendant functional groups shows great potential for use as a smart drug-delivery system. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

In this article, the synthesis of two amphiphilic polyaspartamide copolymers, useful to obtain polymeric nanoparticles without using surfactants or stabilizing agents, is described. These copolymers were obtained starting from α,β-poly-(N-2-hydroxyethyl)- dl-aspartamide (PHEA) by following a novel synthetic strategy. In particular, PHEA and its pegylated derivative (PHEA-PEG) were functionalized with poly(lactic acid) (PLA) through 1,1′-carbonyldiimidazole (CDI) activation to obtain PHEA–PLA and PHEA-PEG–PLA graft copolymers, respectively. These copolymers were properly purified and characterized by H-NMR, FT-IR, and Size Exclusion Chromatography (SEC) analyses, which confirmed that derivatization reactions occurred. Nanoparticles were obtained from PHEA–PLA and PHEA-PEG–PLA graft copolymers by using the high pressure homogenization-solvent evaporation method, avoiding the use of surfactants or stabilizing agents. Polymeric nanoparticles were characterized by dimensional analysis, before and after freeze-drying process, and Scanning Electron Microscopy (SEM). Zeta potential measurements and X-ray Photoelectron Spectroscopy (XPS) analysis demonstrated the presence of PEG and/or PHEA onto the PHEA-PEG–PLA and PHEA–PLA nanoparticle surface, respectively. [ABSTRACT FROM AUTHOR]

Poly(ε-caprolactone)-poly(ethylene glycol)-poly(ε-caprolactone) (PCL-PEG-PCL) multiblock copolymers at various hydrophobic-hydrophilic ratios were successfully synthesized by the chain extension of triblock copolymers through isocyanate (hexamethylene diisocyanate). Biodegradable films were prepared from the resulting multiblock copolymers using the casting method. The mechanical properties of the films were improved by chain extension of the triblock copolymers, whereas the films prepared by the triblock copolymers were weak and brittle. Atomic force microscopy (AFM) of the multiblock copolymer film showed that the hydrophilic PEG had segregated on the film surface. This is consistent with the observed contact angle of the films. [ABSTRACT FROM AUTHOR]

Novel amphiphilic and biodegradable gels composed of glucopyranoside, poly (ϵ-caprolactone) (PCL, n =25-63), and poly (ethylene glycol) (PEG, m = 3) were synthesized. Methyl 2,3-di-O-benzyl-α-D-glucopyranoside was used as an initiator for ring-opening polymerization (ROP) of ϵ-caprolactone (ϵ-CL). The primary hydroxyl group (6-OH) in the above sugar derivative acted chemoselectively as the initiator for living ROP of ϵ-CL, yielding sugar-headed PCL with various lengths of PCL-chains The polymerization temperature (60°C) is very important to suppress the competitive initiation reaction from the secondary hydroxyl group (C4-OH). In order to prepare the cross-linker, both α and ω-termini of PEO (n = 3 and 23) were converted to dicarboxylic chlorides, which actually acted as a coupling reagent for tailor-made amphiphilic biodegradable gel having a sequence of "Sugar-PCL-PEG-PCL-Sugar." [ABSTRACT FROM AUTHOR]

Ionic conductivity and mechanical properties of a mixed polymer matrix consisting of poly(ethylene glycol) (PEG) and cyanoresin type M (CRM) with various lithium salts and plasticizer were examined. The CRM used was a copolymer of cyanoethyl pullulan and cyanoethyl poly(vinyl alcohol) with a molar ratio of 1:1, mixed plasticizer was ethylene carbonate (EC) and propylene carbonate (PC) at a volume ratio of 1:1. The conductive behavior of polymer electrolytes in the temperature range of 298∼338 K was investigated. The PEG/LiClO4 complexes exhibited the highest ionic conductivity of ∼10−5 S/cm at 25°C with the salt concentration of 1.5 M. In addition, the plasticized PEG/LiClO4 complexes exhibited improvement of ionic conductivity. However, their complexes showed decreased mechanical properties. The improvement of ionic conductivity and mechanical properties could be obtained from the polymer electrolytes by using CRM. The highest ionic conductivity of PEG/CRM/LiClO4/(EC-PC) was 5.33×10−4 S/cm at 25°C. [ABSTRACT FROM AUTHOR]

. SC102, a poly(ethylene glycol) (PEG-2000) derivative of the second generation photosensitiser temoporfin (Foscan), was evaluated for photodynamic activity utilising two standard animal models: the rabbit, inoculated with the cottontail rabbit papilloma virus (CRPV) and the healthy canine larynx. Optimal drug dose and drug–light interval (DLI) were determined in a series of pharmacokinetic experiments using SC102 administered intravenously at doses of 3 and 30 mg/kg in our standard CRPV rabbit model. Plasma pharmacokinetics in the rabbit showed an elimination half-life of 121±20 h. Peak tumour concentration occurred at 144 h for the 3 mg/kg group and at 240 h for the 30 mg/kg group. The disposition ratio of SC102 between tumour to healthy tissue, at peak tumour levels, was approximately 4 to 1 for both dose levels. Skin tolerance to increasing 652 nm wavelength fluences was excellent. Even in those rabbits given a 30 mg/kg SC102 dose, no significant damage to the skin was observed, even when a fluence of 160 J/cm2 was applied at the optimal drug–light interval of 10 days. Tumour efficacy of SC102 PDT was evaluated in rabbits previously inoculated with CRPV. One time photoactivation of a single 30 mg/kg dose of SC102 at a DLI of 10 days using a fluence of 100 J/cm2 achieved a complete tumour clearance rate of 35%. Two-time photoactivation on days 6 and 10 after single administration of the same dose in a separate group of rabbits, using a fluence of 75 J/cm2 on both occasions, yielded an improved cure rate of 58%. Evaluation of normal tissue tolerance to SC102 PDT was also investigated in the healthy dog larynx model 10 days after an intravenous dose of 30 mg/kg SC102. A fluence of 200 J was determined to be the maximum tolerated dose at which time there was a 4:1 ratio of SC102 between laryngeal mucosa and muscle. The photophysical and pharmacokinetic profiles of SC102 show significant differences from those of Foscan from which it is derived. In these preliminary in vivo experiments we have demonstrated the outstanding tolerance of normal tissues to SC102 PDT using high fluences. We have also shown tumour efficacy with light doses readily achievable in the clinical setting. Disposition of SC102 in the skin is low and photosensitivity risk may disappear within the drug–light interval. Based on these conclusions we believe SC102 PDT may have potential utility as an adjunct to surgical resection of tumours necessitating wide field exposure of normal tissue to activating light. [ABSTRACT FROM AUTHOR]