Structural characterization of cationic bilayers of biological interest and of their assemblies with DNA

• Grant number: 11/13079-9
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: September 01, 2011
• End date: August 31, 2014
• Field of knowledge: Physical Sciences and Mathematics - Physics - Condensed Matter Physics
• Principal Investigator: Maria Teresa Moura Lamy
• Grantee: Julio Henrique Kravcuks Rozenfeld
• Host Institution: Instituto de Física (IF). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

DiC14-amidine and DODAB are cationic lipids that present biological applications in nucleic acid delivery to cells and in the generation of immune responses. DiC14-amidine has two titratable groups (amine and amidine) and its bilayer structure is sensitive to pH. DODAB has a quaternary ammonium group with a permanent charge that is independent of pH. The aim of this project is to characterize the structures of bilayers prepared with DODAB, DiC14-amidine or lipids containing longer alkyl chains, namely DiC16- and DiC18-amidine, which may also have interesting biological properties. The effects of temperature, pH and presence of DNA molecules will be investigated. The bilayer structures will be compared to the ones formed by the zwiterionic lipids DMPC, DPPC and DSPC, which have alkyl chains of the same size as those of the cationic lipids. The characterization of the structure and colloid stability of these lipid bilayers will be achieved by using techniques such as electron paramagnetic resonance spectroscopy, fluorescence spectroscopy, differential scanning calorimetry, turbidimetry and dynamic light scattering. The immune responses induced by supramolecular assemblies of DODAB bilayers and plasmids coding for human papillomavirus (HPV) antigens will be tested in vivo. This work will be performed in collaboration with the groups of Professors Jean-Marie Ruysschaert (Brussels, Belgium) and Luís Carlos de Souza Ferreira (São Paulo, Brazil). (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

ROZENFELD, JULIO H. K.; DUARTE, EVANDRO L.; RUYSSCHAERT, JEAN-MARIE; LONEZ, CAROLINE; LAMY, M. TERESA. Structural characterization of novel cationic diC16-amidine bilayers: Evidence for partial interdigitation. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES, v. 1848, n. 1, p. 7-pg., 2015-01-01. (11/13079-9)