Polyethylenimine PEI

Malek A, Czubayko F, Aigner A (2008) PEG grafting of polyethylenimine (PEI) exerts different effects on DNA transfection and siRNA-induced gene targeting efficacy. J Drug Target 16 124-139... 

Elfinger M, Pfeifer C, Uezguen S, Golas MM, Sander B, Maucksch C, Stark H, Aneja MK, Rudolph C (2009) Self-assembly of ternary insulin-polyethylenimine (PEI)-DNA nanoparticles for enhanced gene delivery and expression in alveolar epithelial cells. Biomacromolecules 10 2912-2920... 

Fig. 4. Extent of binding of methyl orange at pH 7.0 and 25°C as a function of free (nonbound) dye concentrations (1) polyethylenimine with 8.4% of residues acylated by lauroyl groups (2) polyethylenimine with 11.5% of residues acylated by hexanoyl groups (3) polyethylenimine with 10% of residues acylated by butyrl (O) or isobutyrl ( ) groups (4) Polyethylenimine, PEI-600 (5) bovine serum albumin.

Polyethylenimine (PEI) stock The transfection reagent (Aldrich, catalogue number 40,872-7 25 kDa branched PEI ). Stock solution of PEI is prepared as follows prepare stock solution of 100 mg/ml PEI in water, mix and further dilute to 1 mg/ml, neutralize with HCI and filter sterilize store 5 ml aliquots frozen. 

The use of a monolithic stirred reactor for carrying out enzyme-catalyzed reactions is presented. Enzyme-loaded monoliths were employed as stirrer blades. The ceramic monoliths were functionalized with conventional carrier materials carbon, chitosan, and polyethylenimine (PEI). The different nature of the carriers with respect to porosity and surface chemistry allows tuning of the support for different enzymes and for use under specific conditions. The model reactions performed in this study demonstrate the benefits of tuning the carrier material to both enzyme and reaction conditions. This is a must to successfully intensify biocatalytic processes. The results show that the monolithic stirrer reactor can be effectively employed in both mass transfer limited and kinetically limited regimes. 

An interesting polymer constrained to a relatively compact conformation is polyethylenimine (PEI), which can be prepared by suitable polymerization of ethylenimine (Fig. 2) to give a highly branched rather than a linear macromolecule.19 The structure of a segment of this polymer is shown in Fig. 2. Approximately 25% of its nitrogens are primary amines, 50% secondary, and 25% tertiary.19 The branching of the polymer may be represented schematically as shown in Fig. 3. 

Fig. 6. Rates of esterolysis of p-nitrophenyl caproate at pH7.3 and 25°C in presence of a derivative of polyethylenimine (PEI-600) containing 10% of its residues alkylated with dodecyl groups and 15% alkylated with methyleneimidazole substituents. The numbers shown adjacent to each curve are the residue molar concentrations of imidazole groups in solution. Initial concentration of substrate was 1 x 10-4M.

Wiseman, J.W., Goddard, C.A., McLelland, D., Colledge, W.H. (2003). A comparison of linear and branched polyethylenimine (PEI) with DCChol/DOPE liposomes for gene delivery to epithelial cells in vitro and in vivo. Gene Then, 10(19), 1654—1662. 

Polymethylmethacrylate (PMMA) Polyisodecylmethacrylate Polyacrylic acid (PAA) Polyacrylamide (PAAm) Hydrolyzed polyacrylamide Glyoxylyzed polyacrylamide Polyisobutylene (PIB) Polyethyleneoxide (PEO) Polystyrene Polystyrenesulfonate Polyethylenimine (PEI) Polyvinylalcohol (PVA) Polyvinylpyrrolidone (PVP) Poly-cw-isoprene (PCIP)... 

Mui et al., 2000 Ross et al., 1998). The high transfection efficacy of the cationic polymer polyethylenimine (PEI) involves its strong buffering capacity, inducing osmotic swelling of endosomes leading to their rupture. 

Erbacher, P., Bettinger, T., Belguise-Valladier, P., Zou, S., Coll, J.L., Behr, J.P. et al (1999) Transfection and physical properties of various saccharide, poly(ethylene glycol) and antibody-derivatized polyethylenimines (PEI). J. Gene Med., 1,210-222. 

Poulain, L., Ziller, C., Muller, C.D., Erbacher, P., Bettinger, T., Rodier, J.-F. and Behr, J.-P. (2000) Ovarian carcinoma cells are effectively transfected by polyethylenimine (PEI) derivatives. Cancer Gene Ther., 7, 644-652. 

Werth S, Urban-Klein B, Dai L, Hdbel S, Grzelinski M, Bakowsky U, Czubayko F, Aigner A (2006) A low molecular weight fraction of polyethylenimine (PEI) displays increased transfection efficiency of DNA and siRNA in fresh or lyophilized complexes. J Control Release 112(2) 257-270... 

Peng Q, Zhong Z, Zhuo R (2008) Disulfide cross-linked polyethylenimines (PEI) prepared via thiolation of low molecular weight PEI as highly efficient gene vectors. Bioconjug Chem 19 499-506... 

Synthetic polymer. Among the cationic synthetic polymers used for gene delivery are polyethylenimine (PEI), polyamidoamine dendrimers, and poly(2-dimethylaminoethyl methacrylate).161-164 Depending on the flexibility (or rigidity) of the polymers, they form either a small (<100 nm) DNA polyplex or a large (>1 to 10 pm) DNA polyplex.165 More detailed physicochemical properties and their transfection efficacy are to be discussed. 

Several polycations with a good buffering capacity below physiological pH, such as lipopolyamines and polyamidoamine polymers, have proved to be efficient transfection agents (Boussif et al., 1995). Two of the most popular methods based on polycations are discussed below diethylami-noethyl-dextran (DEAE-dextran) and polyethylenimine (PEI). 

Polyethylenimines (PEIs) with Adducts that Self-assemble into Catalytic Moieties... 

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