Morphological and Nanomechanical Behavior of Supported Lipid Bilayers on Addition of Cationic Surfactants

• Type: Article in International Scientific Journal
• Date: 2013

Authors

Lia M C Lima (Author) Other; Marina I Giannotti (Author) Other; Lorena Redondo Morata (Author) Other; Luisa L C Vale (Author) FCUP; Eduardo F Marques (Author) FCUP; Fausto Sanz (Author) Other

Journal

Title: Langmuir

Vol. 29

Pages: 9352-9361

ISSN: 0743-7463

Publisher: American Chemical Society

Indexing

ISI Web of Knowledge - 22 Citations

Scopus - 22 Citations

Scientific classification

FOS: Engineering and technology > Materials engineering

Associated Projects

115212_2009 - Uma nova abordagem à veiculação de fármacos: lipossomas cataniónicos e nanotubos baseados em derivados de aminoácidos

Other information

Authenticus ID: P-006-92V

DOI: 10.1021/la400067n

Abstract (EN): The addition of surfactants to lipid bilayers is important for the modulation of lipid bilayer properties (e.g., in protein reconstitution and development of nonviral gene delivery vehicles) and to provide insight on the properties of natural biomembranes. In this work, the thermal behavior, organization, and nanomechanical stability of model cationic lipid-surfactant bilayers have been investigated. Two different cationic surfactants, hexadecyltrimethylammonium bromide (CTAB) and a novel derivative of the amino acid serine (Ser16TFAc), have been added (up to 50 mol %) to both liposomes and supported lipid bilayers (SLBs) composed by the zwitterionic phospholipid DPPC. The thermal phase behavior of mixed liposomes has been probed by differential scanning calorimetry (DSC), and the morphology and nanomechanical properties of mixed SLBs by atomic force microscopy based force spectroscopy (AFM-FS). Although DSC thermograms show different results for the two mixed liposomes, when both are deposited on mica substrates similar trends on the morphology and the mechanical response of the lipid-surfactant bilayers are observed. DSC thermograms indicate microdomain formation in both systems, but while CTAB decreases the degree of organization on the liposome bilayer, Ser16TFAc ultimately induces the opposite effect. Regarding the AFM-FS studies, they show that microphase segregation occurs for these systems and that the effect is dependent on the surfactant content. In both SLB systems, different microdomains characterized by their height and breakthrough force F-b are formed. The molecular organization and composition is critically discussed in the light of our experimental results and literature data on similar lipid-surfactant systems.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 10