Poly(ethylene glycol) (PEG) side-chain functionalized lactide analogues have been synthesized in four steps from commercially available L-lactide. The key step in the synthesis is the 1,3-dipolar cycloaddition between PEG-azides and a highly strained spirolactide-heptene monomer, which proceeds in high conversions. The PEG-grafted lactides analogues were polymerized via ring-opening polymerization using triazacyclodecene as organocatalyst to give well-defined tri- and hepta-(ethylene glycol)-poly(lactide)s (PLA) with molecular weights above 10 kDa and polydispersity indices between 1.6 and 2.1. PEG-poly(lactide) (PLA) with PEG chain M(n) 2000 was also prepared but GPC analysis showed a bimodal profile indicating the presence of starting macromonomer. Cell adhesion assays were performed using MC3T3 E-1 osteoblast-like cells demonstrating that PEG-containing PLA reduces cell adhesion significantly when compared to unfunctionalized PLA. 相似文献
A series of multiblock poly(ether urethane)s comprising poly(ethylene glycol) (PEG), and poly(propylene glycol) (PPG) segments were synthesized. Their aqueous solutions exhibited thermogelling behavior at critical gelation concentrations (CGC) ranging from 8 to 12 wt%. The composition and structural information of the copolymers were studied by GPC and 1H NMR. The critical micellization concentration (CMC) and thermodynamic parameters for micelle formation were determined at different temperatures. The temperature response of the copolymer solutions were studied and found to be associated with the composition of the copolymers. 相似文献
(Lactic acid, ethylene glycol, malonic or succinic acid) copolymers [(LA-EG-MA) and (LA-EG-SA) copolymers] were synthesized with different monomer feed ratios by direct polycondensation. The copolymers were characterized in terms of various properties such as acid value and number average molecular weight. The aerobic biodegradation under controlled composting conditions of commercially available and laboratory synthesized poly(l-lactic acid) (PLA) and synthesized copolymers was carried out according to ISO 14855-1:2005. The biodegradability of tested materials was found to be strongly dependent on the lactic acid content, ranging from 94% (method A) and 104% (method B) to 43% (method A) and 46% (method B) over the 110-days of the 50 °C composting. 相似文献
Sorption of poly(ethylene glycol) on poly(ethylene terephthalate) track membranes was studied at different pH. The hydrophilic-hydrophobic properties of the intact membranes and those modified with poly(ethylene glycol) are compared. The membrane-aqueous human serum albumin and membrane-aqueous insulin adhesive tensions were determined for modified membranes. The competitive sorption of human serum albumin and poly(ethylene glycol) from aqueous solution on the track membranes is analyzed. 相似文献
Summary: The reaction of triphosgene with poly(ethylene glycol) yielded poly(ethylene glycol) dichloroformate. This difunctional cross‐linker was allowed to react with poly(ε‐caprolactone) bearing carbanionic sites obtained by activation with lithium diisopropylamide. The reaction resulted in the cross‐linking of poly(ε‐caprolactone) chains by poly(ethylene glycol) segments, giving copolymer networks that gel in both organic and aqueous media.
Schematic of the PCL‐g‐PEG copolymers synthesized here. 相似文献
A biocompatible complex has been prepared as gene carrier via electrostatic interaction, which is composed of a polycation, that is, poly[(dimethylamino)ethyl methacrylate] end-capped with cholesterol moiety (Chol-PDMAEMA30), along with a polyanion named poly(aspartic acid)-grafted-poly(ethylene glycol) (PASP-g-PEG). The complexes have less cytotoxicity compared to the case of alone Chol-PDMAEMA30 or branched polyethylenimine (PEI) system. In the present study, biocompatible complexes have been prepared as gene carrier via electrostatic interaction, which is composed of a polycation, that is, poly[(dimethylamino)ethyl methacrylate] end-capped with cholesterol moiety (Chol-PDMAEMA30), along with a polyanion named poly(aspartic acid)-grafted-poly(ethylene glycol) (PASP-g-PEG). We first synthesized polysuccinimide (PSI) via condensation polymerization of aspartic acid, and then used PEG-NH2 to react with the partial pentacyclic rings of PSI to yield a kind of graft copolymer polysuccinimide-grafted-poly(ethylene glycol) (PSI-g-PEG). After hydrolysis of the residual succinimide units, a new biodegradable and biocompatible graft copolymer PASP-g-PEG was prepared successfully. Chol-PDMAEMA30 was synthesized via oxyanion-initiated polymerization, as reported in our previous literature. We investigated the interactions between every pair among calf thymus DNA, Chol-PDMAEMA30, and PASP-g-PEG by agarose gel retardation assay. The results indicate that the prepared complexes could completely bind DNA and may become more stable during systemic circulation. The complexes have less cytotoxicity compared to the case of alone Chol-PDMAEMA30 or branched polyethylenimine (PEI) system. Furthermore, the physicochemical properties of the complexes were also investigated by zeta potential, transmission electron microscopy (TEM) and dynamic light scattering (DLS) measurements. These biodegradable and biocompatible polymeric carriers have potential applications in gene delivery. 相似文献
Poly(acrylic acid)s (PAAs) modified with a series of fluorocarbon group (Rf) end-capped Poly(ethylene glycol) (PEG) macromonomers(number of ethylene oxide unit:1,9,23,45) and corresponding copolymers without fluorocarbon end groups were synthesized.It was found that the effect of the hydrophobic association of fluorocarbon groups on the solution viscosity prevailed over that of the hydrogen bond between grafted PEG and the backbone.Rheological measurement on the aqueous solutions of these poly(acrylic acid-co-Rf-PEG macromonomer) s demonstrated that the best thickening performance was shown when the number of ethylene oxide unit (EO number) was 23. 相似文献
Poly (L-lactide)-poly (ethylene glycol) multiblock copolymers with predetermined block lengths were synthesized by polycondensation of PLA diols and PEG diacids. These copolymers presented special properties, such as better miscibility between the two components, low crystallinity and better hydrophilicity, which can be modulated by adjusting the block lengths of the two components. 相似文献
Amphiphilic graft copolymers composed of biocompatible bacterial poly(3-hydroxyalkanoate) and poly(ethylene glycol) have been synthesized by thiol-ene addition. They were demonstrated to form well-defined nanoscale vesicles in water by cryo-transmission electron microscopy. 相似文献
Block copolymers were synthesized by ring‐opening polymerization of L ‐lactide or D ‐lactide in the presence of mono‐ or dihydroxyl poly(ethylene glycol), using zinc metal as catalyst. The resulting copolymers were characterized by various techniques, namely 1H NMR spectroscopy, differential scanning calorimetry (DSC), X‐ray diffractometry, and Raman spectrometry. The composition of the copolymers was designed such that they were water soluble. Bioresorbable hydrogels were prepared from aqueous solutions containing both poly(L ‐lactide)/poly(ethylene glycol) and poly(D ‐lactide)/poly(ethylene glycol) block copolymers. Rheological studies confirmed the formation of hydrogels resulting from stereocomplexation between poly(L ‐lactide) and poly(D ‐lactide) blocks.
Ring‐opening polymerization of L (D )‐lactide in the presence of dihydroxyl PEG using zinc powder as catalyst. 相似文献
In this study, ethylene glycol polyesteramide (Eg-PEA) was synthesized from N,N-bis (2-hydroxy ethyl) pongamia oil fatty amide and ethylene glycol tetraacetic acid (EGTA) through condensation polymerization. It was further modified by toluene 2,4-diisocynate in different wt.% (20, 25, 30, and 35) to obtain urethane-modified polyesteramide (Eg-UPEA). The synthesized resins were characterized using FT-IR, 1H NMR, and 13C NMR spectroscopic techniques, and molecular weight was determined by gel permeation chromatography (GPC). Physico-chemical and physico-mechanical analyses were carried out by standard laboratory methods. Thermal studies of Eg-UPEA were undertaken by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) techniques. To evaluate corrosion prevention performance Eg-UPEA-coated mild steel strips were investigated by potentiodynamic polarization in different corrosive media (5 wt.% NaCl, 3 wt.% HCL, 2.5 wt.% NaOH, and tap water) at room temperature. Thermal analysis revealed that Eg-UPEA30 may find application as an environmentally friendly corrosion protective coating and may be safely used up to 250°C. 相似文献
A number of highly functionalized dioxocyclams with acetic acid side chains on the secondary amine sites and ethylene glycol side chains on 6 and 13-positions (12a, 12b) or a tetra(ethylene glycol) side chain linking the 6 and 13 positions (15) were synthesized and characterized, as was a bis-dioxocyclam bridged across the 6 and 13 positions by tetra(ethylene glycol) groups (16). These were screened for their ability to complex Gd3+. Only ligands 15 and 16, having tetra(ethylene glycol) groups, formed such complexes. 相似文献