Thermotropic liquid-crystalline behavior of some single- and double-chained pyridinium amphiphiles

Sudhölter, E.J.R.; Engberts, Jbfn; Dejeu, Wh

doi:10.1021/j100207a035

Cited by 77 publications

(46 citation statements)

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“…The resulting alcohol was tosylated, followed by bromination or iodination with LiBr or NaI in acetone: (4-bromobutyl)-trimethylammonium bromide was synthesized as described (21). The general procedure is outlined in Fig.…”

Section: Synthesis Of Amphiphilesmentioning

confidence: 99%

Novel pyridinium surfactants for efficient, nontoxic in vitro gene delivery

Woude

Wagenaar

Meekel

et al. 1997

Proc. Natl. Acad. Sci. U.S.A.

193

159

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Novel, double-chained pyridinium compounds have been developed that display highly efficient DNA transfection properties. The transfection efficiency of several of these compounds is enhanced by an order of magnitude, when compared with the transfection efficiency accomplished with the widely used cationic lipid system, lipofectin. Most importantly, the pyridinium compounds were found to be essentially nontoxic toward cells. Using various reporter genes, such as ␤-galactosidase and pNEO (a gene construct that renders cells resistent to antibiotic derivatives of neomycin like G418), we demonstrate that the enhanced efficiency relates to the fact that a relative higher number of cells in the population is transfected (Ϸ50% in the case of COS cells) by the pyridinium derivatives, whereas the delivery of DNA per cell is also enhanced. Furthermore, application of the pyridinium derivatives shows little cellular preference in their ability to transfect cells. By systematically modifying the structure of the pyridinium amphiphile, i.e., by changing either the headgroup structure or the alkyl chains, some insight was obtained that may lead to unraveling the mechanism of amphiphile-mediated transfection, and thus to protocols that further optimize the carrier properties of the amphiphile. Our results reveal that unsaturated alkyl chains enhance the transfection properties of the pyridinium-based amphiphiles. Preliminary experiments suggest that the structure-dependent improvement of transfection efficiency, when comparing pyridinium derivatives with lipofectin, likely relates to the mechanism of delivery rather than the packaging of the amphiphile͞DNA complex.

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Section: Synthesis Of Amphiphilesmentioning

confidence: 99%

Novel pyridinium surfactants for efficient, nontoxic in vitro gene delivery

Woude

Wagenaar

Meekel

et al. 1997

Proc. Natl. Acad. Sci. U.S.A.

193

159

View full text Add to dashboard Cite

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“…Moreover, it was observed that the 1-methyl-4-alkoxycarbonylpyridinium iodides salts have thermochromic properties. Color changes were observed on heating at both crystal to crystal and crystal to mesophase transitions, while such an observation could not be made for the 1-methyl-4-alkylpyridinium iodides salts [4,12,13].…”

Section: N-methyl Pyridinium Saltsmentioning

confidence: 89%

“…The N-decyl pyridinium salts exhibit SmA mesomorphism, regardless of the counterion, while their N-methyl counterparts show decomposition and no liquid crystalline properties for iodine and nitrate anions, and, for the remaining anions (BF 4 − , ClO 4 − , and DS), the salts decompose before reaching the isotropic phase from the previous SmA phase, suggesting that the thermal properties (melting point, mesophase range, and clearing or decomposition temperature) are sensitive to counterion exchange. Moreover, the two pyridinium salts with DS as counterion are similar in terms of thermal behavior, and this was explained by XRD studies.…”

Section: Progress and Developments In Ionic Liquids 296mentioning

confidence: 99%

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Ionic Liquid Crystals Based on Pyridinium Salts

Cı̂rcu¹

2017

Progress and Developments in Ionic Liquids

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“…Em solventes apolares, micelas são denominadas de reversas ou inversas. As verdadeiras micelas reversas são soluções binárias compostas de detergente e solvente apolar, sem a presença de água (Sudholter & Engberts, 1982;Ravey et al, 1984;Guveli, 1984). Existem controvérsias sobre essa possibilidade de agregação sem água ou qualquer impureza polar (Eicke & Christen, 1978), mas o que no momento importa é que o termo micela reversa também é usado para sistemas ternários (detergente-água-óleo).…”

Section: Introductionunclassified

Aplicação de modelos simples em fenômenos envolvendo monocamadas e micelas

Dias¹

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Dedico este singelo trabalho a minha filhota, Pollyana Hammoud Dias, e a memória de meu pai, Gilberto Luiz Dias. À minha esposa, Nabiha Mohamad Hammoud Dias, pela sua compreensão e pela dedicação com que trata a nossa família.Ao CNPq, pelo apoio financeiro. ii-) Influência da interação eletrostática (neste caso, repulsiva) e tamanho de domínios nas isotermas de monocamadas iônicas insolúveis. Índiceiii-) Influência do tamanho e polaridade do pool aquoso de micelas reversas de AOT na reprotonação de sondas fotoácidas aniônicas. AbstractThe present work focus on the proposition or extension of simple models

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Thermotropic liquid-crystalline behavior of some single- and double-chained pyridinium amphiphiles

Cited by 77 publications

References 0 publications

Novel pyridinium surfactants for efficient, nontoxic in vitro gene delivery

Novel pyridinium surfactants for efficient, nontoxic in vitro gene delivery

Ionic Liquid Crystals Based on Pyridinium Salts

Aplicação de modelos simples em fenômenos envolvendo monocamadas e micelas

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