Formyl-Ended Heterobifunctional Poly(ethylene oxide): Synthesis of Poly(ethylene oxide) with a Formyl Group at One End and a Hydroxyl Group at the Other End

Nagasaki, Yukio; Kutsuna, Takahiko; Iijima, Michihiro; Kato, Masaru; Kataoka, Kazunori; Kitano, Shigeru; Kadoma, Yoshihito

doi:10.1021/bc00032a012

Cited by 98 publications

(63 citation statements)

References 12 publications

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“…We have previously demonstrated several types of heterotelechelic PEG synthesis. For example, acetal-PEG-OK was easily prepared via the anionic polymerization of ethylene oxide initiated with potassium 3,3-diethoxypropanolate [41]. Because the end group of the product is potassium alcoholate, it is possible to prepare acetal-PEG-b-PAMA by simply adding AMA monomer to the reaction mixture after the complete consumption of ethylene oxide monomer [42].…”

Section: Synthesis Of Acetal-peg-b-pama Via Anionic Polymerization Tementioning

confidence: 99%

Engineering of poly(ethylene glycol) chain-tethered surfaces to obtain high-performance bionanoparticles

Nagasaki

2010

Science and Technology of Advanced Materials

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A poly(ethylene glycol)-b-poly [2-(N,N-dimethylamino)ethyl methacrylate] block copolymer possessing a reactive acetal group at the end of the poly(ethylene glycol) (PEG) chain, that is, acetal-PEG-b-PAMA, was synthesized by a proprietary polymerization technique. Gold nanoparticles (GNPs) were prepared using the thus-synthesized acetal-PEG-b-PAMA block copolymer. The PEG-b-PAMA not only acted as a reducing agent of aurate ions but also attached to the nanoparticle surface. The GNPs obtained had controlled sizes and narrow size distributions. They also showed high dispersion stability owing to the presence of PEG tethering chains on the surface. The same strategy should also be applicable to the fabrication of semiconductor quantum dots and inorganic porous nanoparticles. The preparation of nanoparticles in situ, i.e. in the presence of acetal-PEG-b-PAMA, gave the most densely packed polymer layer on the nanoparticle surface; this was not observed when coating preformed nanoparticles. PEG/polyamine block copolymer was more functional on the metal surface than PEG/polyamine graft copolymer, as confirmed by angle-dependent x-ray photoelectron spectroscopy. We successfully solubilized the C 60 fullerene into aqueous media using acetal-PEG-b-PAMA. A C 60 /acetal-PEG-b-PAMA complex with a size below 5 nm was obtained by dialysis. The preparation and characterization of these materials are described in this review.

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Section: Synthesis Of Acetal-peg-b-pama Via Anionic Polymerization Tementioning

confidence: 99%

Engineering of poly(ethylene glycol) chain-tethered surfaces to obtain high-performance bionanoparticles

Nagasaki

2010

Science and Technology of Advanced Materials

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“…) was synthesized following procedures reported by Nagasaki et al [16] and characterized with 1 H NMR (CDCl 3 ; determined 91 % acetal conversion into aldehyde groups) and gel permeation chromatography (GPC) (TSK-gel G3000PWXL and TSK-gel G4000PWXL; 10 mm LiCl in N,N-dimethylformamide (DMF); 0.8 mL min …”

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confidence: 99%

pH‐Responsive Multi‐PEGylated Dual Cationic Nanoparticles Enable Charge Modulations for Safe Gene Delivery

et al. 2007

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In gene therapy, the cytotoxicity of many polycations is undesirable and has been attributed to nonspecific membrane destabilizing effects and intracellular polyplex-mediated toxicity. To help prolong the pharmacokinetic profile of nonviral vehicles for gene delivery, the cationic surface charge of current systems is typically shielded through the conjugation of polyethylene glycol (PEG) chains to the particle surface. However, the design of an intelligent polycation with environment-sensing charge modulations is essential to minimize cytotoxicity and enhance gene expression. We have designed a novel di-cationic block copolymer, poly(aspartate-hydrazide)-block-poly(L-lysine), capable of pH-mediated endosomal membrane disruption based on charge interactions, which has negligible toxicity elsewhere to the cell. The poly(L-lysine) segment, with a high pK(a) value of approximately 9.4, preferentially forms a poly-ion complex with the negative phosphate groups of pDNA, whereas the pH-responsive poly(aspartate-hydrazide) segment, with the comparatively lower pK(a) approximately 5.0, is characterized by a substantial fraction of unprotonated amino groups at physiological pH. As a consequence, complexation between such a polymer and pDNA leads to the formation of a two-layered nanoparticle. In particular, the nanoparticle possesses an unprotonated pH-responsive segment to serve as both a scaffold for acid-labile linkages of various moieties such as aldehyde-PEG and to transition from neutral to charged for disrupting endosomal membranes, and safely enhancing gene expression. Our system supports an endosomal escape mechanism based on charge interactions rather than the proton-sponge effect, and may be an important step towards engineering new classes of intelligent nonviral vectors.

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“…The systematic research on the synthesis of heteroPEGs, such as NH2-PEG-OH and CHO-PEG-OH [6,7], can be applied to new heteroPEG macromonomer synthesis, having a polymerizable end along with a functional group at the other end [8]. Surface plasma polymerization of heteroPEG macromonomer would give tree-like tethered chain on the surface (Fig.…”

Section: Introductionmentioning

confidence: 99%

“…It should be noted that this end-functionalized PEG/PLA is a major outcome of our systematic research on the synthesis of heteroPEG [6,7]. When one of the functional end-groups in the heteroPEG selectively initiates the polymerization of a hydrophobic monomer, a new heterobifunctional AB block copolymer can be created, keeping the other functional group at the PEG chain end available.…”

Section: Introductionmentioning

confidence: 99%

Novel Approaches for The Construction of Cell Specific Surfaces using Heterobifunctinal Poly(ethylene glycol) (PEG).

Otsuka

Nakashima

Nagasaki

et al. 2000

J. Photopol. Sci. Technol.

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Formyl-Ended Heterobifunctional Poly(ethylene oxide): Synthesis of Poly(ethylene oxide) with a Formyl Group at One End and a Hydroxyl Group at the Other End

Cited by 98 publications

References 12 publications

Engineering of poly(ethylene glycol) chain-tethered surfaces to obtain high-performance bionanoparticles

Engineering of poly(ethylene glycol) chain-tethered surfaces to obtain high-performance bionanoparticles

pH‐Responsive Multi‐PEGylated Dual Cationic Nanoparticles Enable Charge Modulations for Safe Gene Delivery

Novel Approaches for The Construction of Cell Specific Surfaces using Heterobifunctinal Poly(ethylene glycol) (PEG).

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