Surface miscibility of EPC/DOTAP/DOPE in binary and ternary mixed monolayers |
| |
Authors: | Rigoletto Thais de Paula Zaniquelli Maria Elisabete Darbello Santana Maria Helena Andrade de la Torre Lucimara Gaziola |
| |
Affiliation: | a Departamento de Processos Biotecnológicos, Faculdade de Engenharia Química, Universidade Estadual de Campinas, UNICAMP, 13083-970 Campinas, SP, Brazil;b Departamento de Química, Faculdade de Filosofia Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, 14040-901 Ribeirão Preto, SP, Brazil;c Centro Universitário das Faculdades Associadas de Ensino-UNIFAE, 13870-377 São João da Boa Vista, SP, Brazil |
| |
Abstract: | Surface pressure (π)-molecular area (A) curves were used to characterize the packing of pseudo-ternary mixed Langmuir monolayers of egg phosphatidylcholine (EPC), 1,2-dioleoyl-3-trimethylammonium propane (DOTAP) and L-α-dioleoyl phosphatidylethanolamine (DOPE). This pseudo-ternary mixture EPC/DOPE/DOTAP has been successfully employed in liposome formulations designed for DNA non-viral vectors. Pseudo-binary mixtures were also studied as a control. Miscibility behavior was inferred from π-A curves applying the additivity rule by calculating the excess free energy of mixture (ΔG(Exc)). The interaction between the lipids was also deduced from the surface compressional modulus (C(s)(-1)). The deviation from ideality shows dependence on the lipid polar head type and monolayer composition. For lower DOPE concentrations, the forces are predominantly attractive. However, if the monolayer is DOPE rich, the DOTAP presence disturbs the PE-PE intermolecular interaction and the net interaction is then repulsive. The ternary monolayer EPC/DOPE/DOTAP presented itself in two configurations, modulated by the DOPE content, in a similar behavior to the DOPE/DOTAP monolayers. These results contribute to the understanding of the lipid interactions and packing in self-assembled systems associated with the in vitro and in vivo stability of liposomes. |
| |
Keywords: | Langmuir monolayers Gene delivery Egg phosphatidylcholine 1,2-Dioleoyl-3-trimethylammonium propane smCaps" >l-α -Dioleoyl phosphatidylethanolamine |
本文献已被 ScienceDirect PubMed 等数据库收录! |
|