Poly ethylene imine

Merdan T, Kunath K, Petersen H, Bakowsky U, Voigt KH, Kopecek J, Kissel T (2005) PEGylation of poly(ethylene imine) affects stability of complexes with plasmid DNA under in vivo conditions in a dose-dependent manner after intravenous injection into mice. Bioconjug Chem 16 785-792... 

Neu M, Germershaus O, Mao S, Voigt KH, Behe M, Kissel T (2007) Crosslinked nanocarriers based upon poly(ethylene imine) for systemic plasmid delivery in vitro characterization and in vivo studies in mice. J Control Release 118 370-380... 

In a system devised to oxidize a dye, glucose oxidase and horseradish peroxidase were coassembled by layer-by-layer alternative adsorption to construct multienzyme films. The peroxidase was adsorbed to poly(styrene sulfonate) while glucose oxidase was adsorbed to poly(ethylene imine), allowing for sequential redox reactions to take place resulting in the subsequent oxidation of the textile dye DA67 [71]. 

A variety of methods for immobilizing polymerized liposomes have been reported. Multiple layers of vesicles were deposited on quartz slides by layer-by-layer assembly (Su 2005). The slides were first coated with a layer of poly(ethylene imine), a... 

In contrast, similar examination of the product obtained by template polymerization of acrylic acid on poly(ethylene imine), using electrophoresis, leads to the conclusion that in this case graft copolymer is absent. 

Paper chromatography was also used to separate the complex obtained by polymerization of acrylic acid in the presence of poly(ethylene imine). In this case, both the complex obtained by mixing of two polymers and the complex obtained in template polymerization gave two distinct spots. No trace was found of any graft copolymer. 

Keywords Applications Cytotoxicity profile Gene delivery Hyperbranched polyamines Poly(amido amine) Poly(amido ester) Poly(ethylene imine) Polyglycerol amines Structure-property dependence Synthesis Transfection efficiency... 

Plasmid (encodes a red-shifted variant of wild-type GFP) PEGylated poly(ethylene imine)... 

The molecular weight of the polymers is controlled by the initiator/monomer ratio. The first hyperbranched polymer obtained via ROP is poly(ethylene imine) (PEI) (Scheme 1). 

Furthermore, we studied the influence of the molecular weight and degree of branching on transfection efficiency and cell toxicity, which is supposed to have influence, as initially analyzed in several adherent cell lines (NIH/3T3, CHO-K1, COS-7, and HeLa), with unfunctionalized poly(ethylene imine)s [91, 95, 96]... 

Scheme I Synthesis of hyperbranched poly(ethylene imine) (PEI) via acid catalyzed ring-opening polymerization of aziridine. Each color represents a different branching unit blue for linear units (L), black for dendritic units (D), red for terminal units (T). PEI has a degree of branching (DB) of 62-73%, the depicted structure represents only a small idealized fragment. Reproduced with permission from [91]...

Lou Y-L, Peng Y-S, Chen B-H et al (2009) Poly(ethylene imine)-g-chitosan using EX-810 as a spacer for nonviral gene delivery vectors. J Biomed Mater Res A 88A(4) 1058-1068... 

Breunig M, Hozsa C, Lungwitz U et al (2008) Mechanistic investigation of poly(ethylene imine)-based siRNA delivery disulfide bonds boost intracellular release of the cargo. J Control Release 130 57-63... 

Griffiths PC, Alexander C, Nilmini R et al (2008) Physicochemical characterization of thermoresponsive poly(N-isopropylacrylamide)-poly(ethylene imine) graft copolymers. Biomacromolecules 9 1170-1178... 

Neural stem cells are known for their sensitivity to the environment. Jan and Kotov reported the differentiation of mouse embryonic neural stem cells on SWNT-polyelectrolyte multilayer thin films [poly(ethylene imine) PEI/SWNT, six layers], which were assembled layer by layer.111 The cells were successfully differentiated to neurons, astrocytes, and oligodendrocytes with a clear formation of neurites. Compared to the widely used poly(L-ornithine) (PLO) substrates, the six-layer PEI/ SWNT thin films exhibited similar properties in terms of biocompatibihty, neurites outgrowth, and the expression of neural markers.111... 

PEDOT PEELS PEG PEG-Si PEI PEO PEP PER PET PG PG-zb Ph phim PHMA PI pia PIXIES poly-(3,4-ethylenedioxythiophene) parallel electron energy loss spectroscopy poly(ethylene glycol) 2-[methoxypoly(ethyleneoxy)propyl]trimethoxysilane poly(ethylene imine) poly(ethylene oxide) poly(ethylene-aZf-propylene) photoelectrorheological (effect) positron emission tomography adaptor protein G Fc domain of PG phenyl benzimidazolate poly(w-hexyl methacrylate) polyisoprene V-4-pyridyl isonicotinamide protein imprinted xerogels with integrated emission sites... 

Scheme 10 Structure of hyperbranched poly(ethylene imine) 26 and functionalization of PEI with a glycidol (PEIXGLY), b gluconic acid (PEI GLU) and c lactobionic acid (PEIXLAC)...

Table 1.B Characterization of Combburst poly(ethylene imine) [89]a (polymeric dendrimer)...

Three different ways have been developed to produce nanoparticle of PE-surfs. The most simple one is the mixing of polyelectrolytes and surfactants in non-stoichiometric quantities. An example for this is the complexation of poly(ethylene imine) with dodecanoic acid (PEI-C12). It forms a solid-state complex that is water-insoluble when the number of complexable amino functions is equal to the number of carboxylic acid groups [128]. Its structure is smectic A-like. The same complex forms nanoparticles when the polymer is used in an excess of 50% [129]. The particles exhibit hydrodynamic diameters in the range of 80-150 nm, which depend on the preparation conditions, i.e., the particle formation is kinetically controlled. Each particle consists of a relatively compact core surrounded by a diffuse corona. PEI-C12 forms the core, while non-complexed PEI acts as a cationic-active dispersing agent. It was found that the nanoparticles show high zeta potentials (approximate to +40 mV) and are stable in NaCl solutions at concentrations of up to 0.3 mol l-1. The stabilization of the nanoparticles results from a combination of ionic and steric contributions. A variation of the pH value was used to activate the dissolution of the particles. 

The second way of forming nanoparticles of PE-surfs is to use water-soluble block-copolymers with one complexable (ionic) block and one non-com-plexable (nonionic) block. For example, the mesomorphous complexes (solid state) between poly(ethylene oxide)—b-poly(ethylene imine)s and dodecanoic acid can easily by dispersed in water to form nanoparticles [117]. The nanoparticles are of core-shell type and have sizes around 200 nm. Their cores are formed by poly( ethylene imine) dodecanoate while their shells consist of poly(ethylene oxide). It was found that the shapes of the nanoparticles depend on the PEI block. They are, for example, prolate if the PEI is linear and spherical if the PEI is branched. 

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