title: Growth of cationic lipid toward bilayer lipid membrane by solution spreading: scanning probe microscopy study.
abstract: The growth of cationic lipid dioctadecyldimethylammonium bromide (DODAB) toward bilayer lipid membrane (BLM) by solution spreading on cleaved mica surface was studied by atomic force microscopy (AFM). Bilayer of DODAB was formed by exposing mica to a solution of DODAB in chloroform and subsequently immersing into potassium chloride solution for film developing. AFM studies showed that at the initial stage of the growth, the adsorbed molecules exhibited the small fractal-like aggregates. These aggregates grew up and expanded laterally into larger patches with time and experienced from monolayer to bilayer, finally a close-packed bilayer film (5.4+/-0.2 nm) was approached. AFM results of the film growth process indicated a growth mechanism of nucleation, growth and coalescence of dense submonolayer, it revealed the direct information about the film morphology and confirmed that solution spreading was an effective technique to prepare a cationic bilayer in a short time.
authors.affiliation: State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, People's Republic of China.
authors.forename: Li
authors.initials: L
authors.lastname: Wang
authors.forename: Yonghai
authors.initials: Y
authors.lastname: Song
authors.forename: Xiaojun
authors.initials: X
authors.lastname: Han
authors.forename: Bailin
authors.initials: B
authors.lastname: Zhang
authors.forename: Erkang
authors.initials: E
authors.lastname: Wang
mesh_terms: D000538:Aluminum Silicates; D002412:Cations; D002725:Chloroform / Q000737:chemistry; D008051:Lipid Bilayers / Q000737:chemistry*; D018625:Microscopy, Atomic Force / Q000379:methods*; D008956:Models, Chemical; D011189:Potassium Chloride / Q000737:chemistry; D000644:Quaternary Ammonium Compounds / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D000538:Aluminum Silicates; D002412:Cations; D008051:Lipid Bilayers; D000644:Quaternary Ammonium Compounds; C015831:dimethyldioctadecylammonium; D011189:Potassium Chloride; D002725:Chloroform; C011934:mica