Ethylene imine, structure

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... 

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]...

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)...

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. 

Crosslinked resins of polyethylene imine structure have been prepared by various methods, including the reactions of polyethylene imine with epichlorohydrine 14), with allyl chloride 15), with ethylene dibromide, 6) or dichloride 17), and with toluene diisocyanate l8>. 

As a final example of a system exhibiting a typical two length-scale self-assembled structure we mention the acid-base complexes of poly(ethylene oxide)-fc/ock-poly(ethylene imine) (PEO-fo-PEI) with dodecanoic acid investigated by Thiinemann and coworkers [137]. A 2 1 ratio of amino func-... 

Poly(imines) are polymers that contain in their backbone amino nitrogens connected by single bonds to carbon atoms. Some of these polymers have a simple structure like poly(ethylene imine) or [-CH2-CH2-NH-]n. The polymer is obtained from the polymerization of aziridine, typically generating a mix of linear and branched macromolecules with about 25% primary amine groups, 50% secondary amine groups, and 25% tertiary amine groups. The polymer is used in paper industry and for various other purposes that make use of its anionic character [1]. 

Fig. 6 Chemical structures of branched copolymers (x and y denote number averages of repeating units) a polyallylamine-gra/t-poly( /-methyl L-glutamate) (PAAx-g-PMLGluy, X = 175, y = 14), b poly(ethylene oxide)- Zoc/c-(branched-poly(ethylene imine)-gra/t-poly(y-benzyl L-glutamate)) (PEOx- -PEIy-g-PBLGlu2(o.4j+i) x = 113, y = 233, z = 0.2-2.9), and c poly(ethylene oxide)-MocA -([G-3]-dendritic poly(L-lysine)-acetal) (PEOx- -[G-3]-PALLys, x = 113, 227)...

Modification of the drug structure by the covalent attachment of a water-solubilizing group through a biodegradable linker (e.g. poly(ethylene glycol) (PEG), poly(ethylene imine) (PEI), a water-soluble polymethacrylate derivative, a poly(amino acid) such as poly... 

Lattermann et al. reported the first metallomesogenic dendrimer when they described results on trigonal bipyramidal metal complexes of ethylene-imine dendrimers of the first and second generation, based on derivatives of tris(2-aminoethyl)amine. Complexes of cobalt, nickel, copper, and zinc were prepared and found to exhibit relatively low temperature mesophases, which generally possessed hexagonal columnar structures. These materials therefore provided the first examples of metallomesogenic dendrimers [72,73]. 

Copolymer complexes of mono- and dialkyl esters of itaconic acid modified by ethylene imines, with C0CI2 and CUCI2, have been obtained with the following structure [73,74]. 

Ethylene imine is a colorless mobile liquid hoving on omine-like odor, with the obove structure. 

Since the first generation of polycations for cell transfection, such as poly (ethylene imine) (PEI, commercially available as ExGen500 or jetPEI in its linear form or as Lipofectamine, which is hyperbranched PEI incorporated in cationic lipids) [18,19], poly(L-lysine) (PLL) [20], poly(amido amine) (PAMAM, Starburst) [8], poly(propylene imine) (PPI) [21, 22], and their derivatives, various other architectures and structural motifs have been designed in order to surpass the... 

Poly(ethylene imine) (PEI) has also been employed for capping a preassembled octahedral iron(III) complex with H2LIO2O (Scheme 4-17) in DMSO in the presence of triethylamine [141]. The formation of amide Unkages has been proved by the presence of a band at 1641 cm" in the IR spectra. However, the formation of a bicapped cage structure remains imcertain. 

PEM were extensively studied in the last decade [1, 4,15] but the knowledge about their structure and properties as a function of the preparation conditions or post preparation treatment still needs to be completed and systematized with precise studies on their stability and response to various external stimuli. The aim of the present work was to summarise data about film swelling and water uptake of PEM prepared from polyallylamine hydrochlo-ride/polysodium 4-styrenesulfonate (PAH/PSS) using different preparation procedures or post preparation treatment. A layer of highly branched poly(ethylene imine) (PEI) is often used as a first layer to anchor subsequent layers to the support material [1] when PEM are formed... 

Self-organization processes proceeding in IPECs are not timited by the nanometer scale, pronouncedly manifesting themselves on the scale corresponding to mesostructures and in bulk. The self-organization can lead to the selective formation of highly ordered structures. An example of such a stracture is stoichiometric IPEC formed by PA anions and protonated linear poly(ethylene imine) (PEI) cations. The study of chemical transformatirais in such macromolecular co-assemblies provided evidence that more than about 80% (mol) of interpolymer salt bonds can be converted to covalent amide braids, as illustrated by Scheme (11) ... 

An understanding of the structure, property relationship in the PET-PEI-Surlyn interface is necessary in order to facilitate the design of laminate structure with desirable performance properties. Therefore, we wish to characterize the chemical nature of the poly(ethylene imine), and polyvinylamine in the tie coat layer between poly(ethylene terepthalate) and Surlyn . 

Figure 9 Effect of Compositiou on Peel Strength, Structure of Protonated Poly (ethylene imine), Poor Peel Strength.

Schematic representation to the reversible temperature-induced control over osmotic flux (top) and the structure of the utilized thermoresponsive butylated branched poly(ethylene imine) (Noh eta ., 2012). 

The polymer can be made into a branch structure by ring-opening polymerizing ethylene imine under an acidic catalyst. Also, a linear polymer can be made by hydrolyzing the poly(N-formylethylene imine) obtained by the ring-opening polymerization of 2-oxazoline with boron trifluoride or sulfuric acid. 

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