The Polymerization of Ethylenimine

Jones, Giffin D.; Langsjoen, Arne; Neumann, Sister Mary Marguerite Christine; Zomlefer, Jack

doi:10.1021/jo01184a002

Cited by 128 publications

(43 citation statements)

References 8 publications

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“…Acid-catalyzed polymerization of aziridine leads to branched PEI, whereas ring opening polymerization of 2-ethyl-2-oxazoline leads to the N-substituted polymer, which can be transformed via hydrolysis into linear PEI [58,156] based on the acid-catalyzed polymerization mechanism of aziridine suggested by Dick and Ham [20]. Moreover, measurements using quantitative C-13 nuclear resonance spectroscopy showed that the degree of branching was actually 1 : 1 : 1 for most commercially available PEIs, suggestive of a more branched structure [21].…”

Section: Pei: Polymer Structure and Molecular Weightmentioning

confidence: 99%

Recent advances in rational gene transfer vector design based on poly(ethylene imine) and its derivatives

Neu

Fischer

Kissel

2005

The Journal of Gene Medicine

804

638

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The continually increasing wealth of knowledge about the role of genes involved in acquired or hereditary diseases renders the delivery of regulatory genes or nucleic acids into affected cells a potentially promising strategy. Apart from viral vectors, non-viral gene delivery systems have recently received increasing interest, due to safety concerns associated with insertional mutagenesis of retro-viral vectors. Especially cationic polymers may be particularly attractive for the delivery of nucleic acids, since they allow a vast synthetic modification of their structure enabling the investigation of structure-function relationships. Successful clinical application of synthetic polycations for gene delivery will depend primarily on three factors, namely (1) an enhancement of the transfection efficiency, (2) a reduction in toxicity and (3) an ability of the vectors to overcome numerous biological barriers after systemic or local administration. Among the polycations presently used for gene delivery, poly(ethylene imine), PEI, takes a prominent position, due to its potential for endosomal escape. PEI as well as derivatives of PEI currently under investigation for DNA and RNA delivery will be discussed. This review focuses on structure-function relationships and the physicochemical aspects of polyplexes which influence basic characteristics, such as complex formation, stability or in vitro cytotoxicity, to provide a basis for their application under in vivo conditions. Rational design of optimized polycations is an objective for further research and may provide the basis for a successful cationic polymer-based gene delivery system in the future.

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Section: Pei: Polymer Structure and Molecular Weightmentioning

confidence: 99%

Recent advances in rational gene transfer vector design based on poly(ethylene imine) and its derivatives

Neu

Fischer

Kissel

2005

The Journal of Gene Medicine

804

638

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“…The molecular weight of PEl was estimated as 9000 from viscosity data. 8 Figure 1 shows a conductometric titration curve for PEl obtained without taking into account the effect of dilution. According to the statement of the manufacturer, the approximate ratio of primary, secondary, and tertiary amines in this PEl was said to be 1 : 2 : 1.…”

Section: Methodsmentioning

confidence: 99%

Formation of a Polyelectrolyte Complex from Carboxymethyl Cellulose and Poly(ethylenimine)

Sato

Nakajima

1975

Polym J

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Formation of a polyelectrolyte complex was investigated as a function of pH by using carboxymethyl cellulose and poly(ethylenimine) as polyanion and polycation components, respectively. Experimental data on turbidity and conductometric and potentiometric titrations led to the conclusion that the formation of the polyelectrolyte complex did not obey stoichiometry. Such a result may be attributed to the less flexible nature of the polyanion molecular chains and to the distribution of ionizable groups on the chains of both components.KEY WORDS Polyelectrolyte Complex I Stoichiometry 1 Carboxymethyl Cellulose I Poly(ethylenimine) 1 Turbidity 1 When a polyelectrolyte reacts with an oppositely charged polyelectrolyte in an aqueous solution, a polyelectrolyte complex is formed. The complex formation with polyelectrolytes may differ from salt formation with microelectrolytes from the viewpoint of molecular conformations, i.e., the formation of a polyelectrolyte complex may not necessarily always be stoichiometric, if, for example, the chain are rigid. The reaction to form a polyelectrolyte complex is influenced by the degree of polymerization, the ionic strength of the medium, the reaction temperature, etc., and depends on pH if at least either the polyanion or the polycation is a weak polyelectrolyte. The polyelectrolyte complex is obtained in the state of a precipitate, a gel or a sol, depending on conditions. In a previous paper/ we have reported a thermodynamic investigation on the complex coacervation phenomena, a phase separation in which polyelectrolytes participate, by using a polycation and a polyanion, both prepared from poly(vinyl alcohol).Backbone chains of vinyl polymers, for example, are regarded to be flexible, while chains of polysaccharides and of polypeptides under some particular conditions are considered to be rigid. The chain flexibility of component polymers should affect the formation and the structure of the complex.In most papers reported to data, complex formations performed under a stoichiometric relation have been investigated. The colloid titration 2 ' 3 is performed under such a conditions. Michaels 4 has pointed out that the reaction of two strong polyelectrolytes with opposite charges, sodium poly(styrene sulfonate) and poly(vinylbenzyl trimethyl ammonium chloride), was stoichiometric. Hosono 5 examined the complex formation from partially sulfated poly(vinyl alcohol) and poly(vinyl alcohol) partially acetallyzed with diethoxy ethyl trimethyl ammonium salt, both of which are strong polyelectrolyte, and has pointed out that the reaction was stoichiometric and did not depend on the pH of the medium.With respect to complexes made by reaction of a strong polyelectrolyte with a weak polyelectrolyte, Fuoss, et al.,6 showed that poly(4-vinyl-n-N-butyl pyridonium bromide) (strong polybase) reacted with sodium polyacrylate (weak polyacid) in nearly stoichiometrical equivalence, and Hosono, et al.,7 have pointed out that partially sulfated poly(vinyl alcohol) reacted with partially aminoa...

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“…The relationship of Am to the reduced viscosity of the 1.0% aqueous solution (a measure of the molecular weight) is shown in figure 9. e was calculated to be about 0.1 from the slope of the reduced viscosity (for *~slo/C~ > 0.2) according to G. D. Jones et al (9). This indicates that the polyethylene imine molecules lie nearly flatly on the membrane surface.…”

Section: Thickness Of the Layers Of Polyethylene Imine On The Surfacementioning

confidence: 97%

Modification of properties of ion exchange membranes V. Structure of cationic polyelectrolyte on the surface of cation exchange membranes

Sata

Izuo

1978

Colloid Polymer Sci

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The Polymerization of Ethylenimine

Cited by 128 publications

References 8 publications

Recent advances in rational gene transfer vector design based on poly(ethylene imine) and its derivatives

Recent advances in rational gene transfer vector design based on poly(ethylene imine) and its derivatives

Formation of a Polyelectrolyte Complex from Carboxymethyl Cellulose and Poly(ethylenimine)

Modification of properties of ion exchange membranes V. Structure of cationic polyelectrolyte on the surface of cation exchange membranes

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