title: Interaction of chitosan with cell membrane models at the air-water interface.
abstract: In this paper we employed phospholipid Langmuir monolayers as membrane models to probe interactions with chitosan. Using a combination of surface pressure--area and surface potential--area isotherms and rheological measurements with the pendent drop technique, we observed that chitosan interacts with phospholipid molecules at the air-water interface. We propose a model in which chitosan interacts with the phospholipids mainly through electrostatic interactions, but also including H-bonding and hydrophobic forces, depending on the phospholipid packing density. At large areas per molecule, chitosan in the subphase adsorbs onto the monolayer, expanding it. At small areas per molecule, chitosan is located in the subsurface. Indeed, a mixed chitosan-phospholipid monolayer can be transferred onto solid supports, even at high surface pressures. The effects of chitosan on the viscoelastic properties of phospholipid monolayers may be taken as evidence for the ability of chitosan to disrupt cell membranes.
authors.affiliation: Instituto de Física de São Carlos, Universidade de São Paulo, São Carlos, Brazil.
authors.forename: Felippe J
authors.initials: FJ
authors.lastname: Pavinatto
authors.forename: Adriana
authors.initials: A
authors.lastname: Pavinatto
authors.forename: Luciano
authors.initials: L
authors.lastname: Caseli
authors.forename: David S Dos
authors.initials: DS
authors.lastname: Santos
authors.forename: Thatyane M
authors.initials: TM
authors.lastname: Nobre
authors.forename: Maria E D
authors.initials: ME
authors.lastname: Zaniquelli
authors.forename: Osvaldo N
authors.initials: ON
authors.lastname: Oliveira
mesh_terms: D000388:Air; D002462:Cell Membrane / Q000737:chemistry*; D048271:Chitosan / Q000737:chemistry*; D006860:Hydrogen Bonding; D057927:Hydrophobic and Hydrophilic Interactions; D008954:Models, Biological; D010743:Phospholipids; D011312:Pressure; D012212:Rheology; D055672:Static Electricity; D014867:Water / Q000737:chemistry*
chemical_list: D010743:Phospholipids; D014867:Water; D048271:Chitosan