scholarly journals Synthesis of Dextran/Methoxy Poly(ethylene glycol) Block Copolymer

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Young-Il Jeong ◽  
Dong-Gon Kim ◽  
Dae-Hwan Kang
Keyword(s):  
Block Copolymer ◽  
Ethylene Glycol ◽  
Gel Permeation Chromatography ◽  
Hydroxyl Group ◽  
Poly Ethylene Glycol ◽  
Nmr Spectrum ◽  
H Nmr ◽  
Glucose Molecule ◽  
Poly Ethylene ◽  
End Group

We synthesized a block copolymer composed of dextran and methoxy poly(ethylene glycol) (mPEG). To accomplish this, the end group of dextran was modified by reductive amination. The aminated dextran (Dextran-NH2) showed the intrinsic peaks of both dextran at 3~5.5 ppm and hexamethylene diamine at 1~2.6 ppm at1H nuclear magnetic resonance (NMR) spectrum. The amino end group of dextran was conjugated with mPEG to make the block copolymer consisting of dextran/mPEG (abbreviated as DexPEG). The synthesized aminated dextran and DexPEG were characterized using1H NMR and gel permeation chromatography (GPC). The molecular weight and conjugation yield were estimated by comparing the intensity ratio of the proton peaks of the glucose molecule (4.9 ppm and 3.3~4.0 ppm) to that of the ethylene group of mPEG (3.7 ppm). Abundant hydroxyl group in the dextran chain can be used as a source of bioactive agent conjugation.

Characterizing Poly(ε-caprolactone)-b-Chitooligosaccharide-b-Poly(ethylene glycol) (PCP) Copolymer Micelles for Doxorubicin (DOX) Delivery: Effects of Crosslinked of Amine Groups

2006 ◽  
Vol 6 (9) ◽  
pp. 2902-2911 ◽  
Author(s):  
Tze-Wen Chung ◽  
Der-Zen Liu ◽  
Jui-Hsiang Hsieh ◽  
Xian-Chan Fan ◽  
Jean-Dean Yang ◽  
...  
Keyword(s):  
Ethylene Glycol ◽  
Polymeric Micelles ◽  
Average Molecular Weight ◽  
Gel Permeation Chromatography ◽  
Infrared Spectrometry ◽  
Burst Release ◽  
Poly Ethylene Glycol ◽  
H Nmr ◽  
Amine Groups ◽  
Poly Ethylene

New amine-groups containing tri-block copolymers and micelles that consisting of poly(ε-caprolactone)-b-chitooligosaccharide-b-poly(ethylene glycol) (PCL-b-COS-b-PEG, PCP), were synthesized, characterized, and evaluated for delivering doxorubicin (DOX) with or without crosslinked amine groups by genipin. The characteristics of the PCP copolymers of Fourier-transform infrared spectrometry (FT-IR) verify the amine and ester groups of the COS and the PCL of the copolymers, respectively. 1H nuclear magnetic resonance (1H NMR) spectra verify the structures of the PCP copolymers consisting two PCL and PEG polymers reacted onto the COS block. In addition, gel permeation chromatography (GPC) determines the number average molecular weight of the triblock copolymers (Mn) of approximately 11340 Da/mole. The PCP copolymers can self-assemble to form polymeric micelles at the critical micelle concentration (CMC) of 1.0 μM as determined by the UV-VIS absorption spectra. The mean diameter of the PCP micelles is 90 nm, as determined using a dynamic light-scattering (DLS) analyzer. Moreover, the zeta potentials of PCP micelles change from neutral to cationic state when pH of suspension mediums varied from 7.4 to 3.0. For evaluating delivery characteristics of hydrophobic DOX, it was loaded into PCP micelles with or without crosslinked by genipin. The burst release and release period of DOX for the crosslinked micelles are significantly reduced (P < 0.003, n = 3, for pH = 7.4) and sustained (e.g., 8 days), respectively, than those non-crosslinked ones (e.g., 4 days). In conclusion, new tri-block amine groups containing PCP copolymers are synthesized that can self-assemble as PCP micelles. After post-crosslinked amine groups of DOX loaded the micelles, they can effectively reduce the burst release and sustain the release of DOX at different pH dissolution mediums. Further applications of PCP copolymers and micelles for drug delivery can be explored in future.

Mixed layers of DPPC and a linear poly(ethylene glycol)-b-hyperbranched poly(glycerol) block copolymer having a cholesteryl end group

2012 ◽  
Vol 290 (7) ◽  
pp. 579-588 ◽  
Author(s):  
Xiaoju Peng ◽  
Anna Maria Hofmann ◽  
Sascha Reuter ◽  
Holger Frey ◽  
Jörg Kressler
Keyword(s):  
Block Copolymer ◽  
Ethylene Glycol ◽  
Poly Ethylene Glycol ◽  
Hyperbranched Poly ◽  
Linear Poly ◽  
Poly Ethylene ◽  
Mixed Layers ◽  
End Group

Synthesis and Characterization of a Novel Triblock Copolymer Containing Double-hydrophilic Blocks and Poly(fluoroalkyl methacrylate) Block via Oxyanioninitiated Polymerization

e-Polymers ◽  
2006 ◽  
Vol 6 (1) ◽  
Author(s):  
Jie Xu ◽  
Peihong Ni ◽  
Jiang Mao
Keyword(s):  
Ethylene Glycol ◽  
Diblock Copolymer ◽  
Triblock Copolymer ◽  
Triblock Copolymers ◽  
Gel Permeation Chromatography ◽  
Monomethyl Ether ◽  
Critical Aggregation Concentration ◽  
Hydroxyl Group ◽  
Poly Ethylene Glycol ◽  
Poly Ethylene

AbstractA new triblock copolymer consisted of a double-hydrophilic diblock and a fluorinated block, namely poly(ethylene glycol)-b-poly[2-(dimethyl amino)-ethylmethacrylate]-b-poly(2,2,3,3,4,4,5,5-octafluoropentylmeth acrylate) (MePEG-b-PDMAEMA-b-POFPMA), was synthesized via oxyanioninitiated copolymerization. The hydroxyl group of poly(ethylene glycol) monomethyl ether (MePEG) reacted with potassium methylsulfinyl carbanion (DMSO-K+) and converted into a potassium alcoholate macroinitiator (MePEG-K). It could initiate DMAEMA monomer to yield a hydrophilichydrophilic diblock copolymer. If not quenched, the living chain could be subsequently used to initiate a second fed monomer such as OFPMA to produce a new triblock copolymer MePEG-b-PDMAEMA-b-POFPMA. As a comparison, the analogous triblock copolymers with different lengths of PDMAEMA and identical length of POFPMA were prepared. These copolymers were characterized by the measurements of 1H NMR, 19F NMR, and gel permeation chromatography (GPC). The results indicated that they had relatively low polydispersities (Mw/Mn̅ :1.25 −1.27) . The comparison of the critical aggregation concentration (CAC) of diblock copolymer MePEG-b- PDMAEMA and triblock copolymer MePEG-b-PDMAEMA-b-POFPMA has been investigated by measurements of surface tension and electrical conductivity. It was also found that the lower critical solution temperatures (LCSTs) of the di- and triblock copolymers varied with different factors, including the chemical structure, the length of DMAEMA block, and the concentration of the aqueous solution.

scholarly journals End group functionalization of poly(ethylene glycol) with phenolphthalein: towards star-shaped polymers based on supramolecular interactions

2014 ◽  
Vol 10 ◽  
pp. 2263-2269 ◽  
Author(s):  
Carolin Fleischmann ◽  
Hendrik Wöhlk ◽  
Helmut Ritter
Keyword(s):  
Ethylene Glycol ◽  
Cycloaddition Reaction ◽  
Supramolecular Interactions ◽  
Poly Ethylene Glycol ◽  
Naked Eye ◽  
Vis Spectroscopy ◽  
End Group Functionalization ◽  
Interesting Approach ◽  
Poly Ethylene ◽  
End Group

The synthesis of a new phenolphthalein azide derivative, which can be easily utilized in polymer analogous reactions, is presented. The subsequent cycloaddition reaction with propargyl-functionalized methoxypoly(ethylene glycol) yielded polymers bearing phenolphthalein as the covalently attached end group. In presence of per-β-cyclodextrin-dipentaerythritol, the formation of stable inclusion complexes was observed, representing an interesting approach towards the formation of star shaped polymers. The decolorization of a basic polymer solution caused by the complexation was of great advantage since this behavior enabled following the complex formation by UV–vis spectroscopy and even the naked eye.

scholarly journals Local Toxicity of Topically Administrated Thermoresponsive Systems: In Vitro Studies with In Vivo Correlation

2018 ◽  
Vol 47 (3) ◽  
pp. 426-432 ◽  
Author(s):  
Sivan Yogev ◽  
Ayelet Shabtay-Orbach ◽  
Abraham Nyska ◽  
Boaz Mizrahi
Keyword(s):  
Block Copolymer ◽  
Ethylene Glycol ◽  
Medical Devices ◽  
Poly Lactic Acid ◽  
Poly Ethylene Glycol ◽  
Thermoresponsive Polymers ◽  
Wide Range ◽  
Poly Ethylene

Thermoresponsive materials have the ability to respond to a small change in temperature—a property that makes them useful in a wide range of applications and medical devices. Although very promising, there is only little conclusive data about the cytotoxicity and tissue toxicity of these materials. This work studied the biocompatibility of three Food and Drug Administration approved thermoresponsive polymers: poly( N-isopropyl acrylamide), poly(ethylene glycol)-poly(propylene glycol)-poly(ethylene glycol) tri-block copolymer, and poly(lactic acid-co-glycolic acid) and poly(ethylene glycol) tri-block copolymer. Fibroblast NIH 3T3 and HaCaT keratinocyte cells were used for the cytotoxicity testing and a mouse model for the in vivo evaluation. In vivo results generally showed similar trends as the results seen in vitro, with all tested materials presenting a satisfactory biocompatibility in vivo. pNIPAM, however, showed the highest toxicity both in vitro and in vivo, which was explained by the release of harmful monomers and impurities. More data focusing on the biocompatibility of novel thermoresponsive biomaterials will facilitate the use of existing and future medical devices.

scholarly journals Sizing and Thermal Stability of Prepared Tetraaminophthalocyaninatocopper(II) Derivatives-grafted Polymers

2016 ◽  
Vol 13 (2) ◽  
pp. 221-234
Author(s):  
Baghdad Science Journal
Keyword(s):  
Thermal Stability ◽  
Ethylene Glycol ◽  
Group Analysis ◽  
Condensation Polymerization ◽  
Grafted Polymers ◽  
Poly Ethylene Glycol ◽  
Molecular Weights ◽  
Poly Ethylene ◽  
Thermal Stability Of ◽  
End Group

Different polymers were prepared by condensation polymerization of sebacic anhydride and adipic anhydride with ethylene glycol and poly(ethylene glycol). Their number average molecular weights were determined by end group analysis. Then, they were grafted on the prepared phthalocyaninatocopper(II) compounds with the general formula (NH2)4PcCu(II) having amino groups of 3,3',3'',3'''- or 4,4',4'',4'''- positions. All prepared polymers, compounds, and phthalocyaninatocopper(II)-grafted polymers were characterized by FTIR. The sizing measurements were carried out in 3,3',3'',3'''- (NH2)4PcCu(II) and 4,4',4'',4'''- (NH2)4PcCu(II) compounds with and without grafting polymers. The results showed that the grafting process led to decreasing in particle size and increasing in surface area. The grafting process was reflected positively on the thermal degradation of 3,3',3'',3'''- (NH2)4PcCu(II) and 4,4',4'',4'''- (NH2)4PcCu(II) grafted polymers. They had higher thermal stability accompanied with higher char residue and T50% weight loss with 3,3',3'',3'''-(NH2)4PcCu(II) and their grafted polymers being the best.

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