title: Physical factors affecting plasmid DNA compaction in stearylamine-containing nanoemulsions intended for gene delivery.
abstract: Cationic lipids have been used in the development of non-viral gene delivery systems as lipoplexes. Stearylamine, a cationic lipid that presents a primary amine group when in solution, is able to compact genetic material by electrostatic interactions. In dispersed systems such as nanoemulsions this lipid anchors on the oil/water interface confering a positive charge to them. The aim of this work was to evaluate factors that influence DNA compaction in cationic nanoemulsions containing stearylamine. The influence of the stearylamine incorporation phase (water or oil), time of complexation, and different incubation temperatures were studied. The complexation rate was assessed by electrophoresis migration on agarose gel 0.7%, and nanoemulsion and lipoplex characterization was done by Dynamic Light Scattering (DLS). The results demonstrate that the best DNA compaction process occurs after 120 min of complexation, at low temperature (4 ± 1 °C), and after incorporation of the cationic lipid into the aqueous phase. Although the zeta potential of lipoplexes was lower than the results found for basic nanoemulsions, the granulometry did not change. Moreover, it was demonstrated that lipoplexes are suitable vehicles for gene delivery.
authors.affiliation: Laboratório de Sistemas Dispersos (LASID), Universidade Federal do Rio Grande do Norte (UFRN), Natal/RN, Brazil. socrates@ufrnet.br.
authors.forename: André Leandro
authors.initials: AL
authors.lastname: Silva
authors.forename: Francisco
authors.initials: F
authors.lastname: Alexandrino
authors.forename: Lourena Mafra
authors.initials: LM
authors.lastname: Verissimo
authors.forename: Lucymara Fassarella
authors.initials: LF
authors.lastname: Agnez-Lima
authors.forename: Lucila Carmem Monte
authors.initials: LC
authors.lastname: Egito
authors.forename: Anselmo Gomes
authors.initials: AG
authors.lastname: de Oliveira
authors.forename: Eryvaldo Socrates Tabosa
authors.initials: ES
authors.lastname: do Egito