title: Aggregation of liposomes induced by calcium: a structural and kinetic study.
abstract: In this work, the calcium-induced aggregation of phosphatidylserine liposomes is probed by means of the analysis of the kinetics of such process as well as the aggregate morphology. This novel characterization of liposome aggregation involves the use of static and dynamic light-scattering techniques to obtain kinetic exponents and fractal dimensions. For salt concentrations larger than 5mM, a diffusion-limited aggregation regime is observed and the Brownian kernel properly describes the time evolution of the diffusion coefficient. For slow kinetics, a slightly modified multiple contact kernel is required. In any case, a time evolution model based on the numerical resolution of Smoluchowski's equation is proposed in order to establish a theoretical description for the aggregating system. Such a model provides an alternative procedure to determine the dimerization constant, which might supply valuable information about interaction mechanisms between phospholipid vesicles.
authors.affiliation: Grupo de Física de Fluidos y Biocoloides, Departamento de Física Aplicada, Universidad de Granada, E-18071 Granada, Spain.
authors.forename: Sándalo
authors.initials: S
authors.lastname: Roldán-Vargas
authors.forename: Alberto
authors.initials: A
authors.lastname: Martín-Molina
authors.forename: Manuel
authors.initials: M
authors.lastname: Quesada-Pérez
authors.forename: Ramon
authors.initials: R
authors.lastname: Barnadas-Rodríguez
authors.forename: Joan
authors.initials: J
authors.lastname: Estelrich
authors.forename: José
authors.initials: J
authors.lastname: Callejas-Fernández
mesh_terms: D002118:Calcium / Q000737:chemistry*; D003102:Colloids / Q000737:chemistry*; D003198:Computer Simulation; D004058:Diffusion; D007700:Kinetics; D008081:Liposomes / Q000737:chemistry*; D008956:Models, Chemical; D008958:Models, Molecular; D008968:Molecular Conformation; D009391:Nephelometry and Turbidimetry / Q000379:methods*; D010743:Phospholipids / Q000737:chemistry*
chemical_list: D003102:Colloids; D008081:Liposomes; D010743:Phospholipids; D002118:Calcium