title: Interaction of chitosan and mucin in a biomembrane model environment.
abstract: Chitosans have been widely exploited in biological applications, including drug delivery and tissue engineering, especially owing to their mucoadhesive properties, but the molecular-level mechanisms for the chitosan action are not known in detail. It is believed that chitosan could affect the mucus by interacting with the proteins mucins, in a process mediated by the cell membrane. In this study we used Langmuir monolayers of dimyristoylphosphatidic acid (DMPA) as simplified membrane models to investigate the interplay between the activity of mucins and chitosan. Surface pressure and surface potential measurements were performed with DMPA monolayers onto which chitosan and/or mucin was adsorbed. We found that the expanding effect from mucin was considerably reduced when chitosan was injected after mucin had been adsorbed on the DMPA monolayer. The results were consistent with the formation of complexes between mucin and chitosan, thus highlighting the importance of electrostatic interactions. Furthermore, chitosan could remove mucin that was co-deposited along with DMPA in Langmuir-Blodgett (LB) films, which could be ascribed to molecular-level interactions between chitosan and mucin inferred from the FTIR spectra of the LB films. In conclusion, the results with Langmuir and LB films suggest that electrostatic interactions are crucial for the mucoadhesive mechanism, which is affected by the complexation between chitosan and mucin.
authors.affiliation: Instituto de Física de São Carlos, Grupo de Polímeros Prof. Bernhard Gross, Universidade de São Paulo, 369, São Carlos, SP, Brazil.
authors.forename: Cristiane A
authors.initials: CA
authors.lastname: Silva
authors.forename: Thatyane M
authors.initials: TM
authors.lastname: Nobre
authors.forename: Felippe J
authors.initials: FJ
authors.lastname: Pavinatto
authors.forename: Osvaldo N
authors.initials: ON
authors.lastname: Oliveira
mesh_terms: D000818:Animals; D002462:Cell Membrane / Q000737:chemistry / Q000378:metabolism; D048271:Chitosan / Q000737:chemistry / Q000378:metabolism*; D020404:Glycerophospholipids / Q000737:chemistry / Q000378:metabolism*; D008562:Membrane Glycoproteins / Q000737:chemistry / Q000378:metabolism*; D008567:Membranes, Artificial; D009077:Mucins / Q000737:chemistry / Q000378:metabolism*; D017550:Spectroscopy, Fourier Transform Infrared; D055672:Static Electricity; D013552:Swine
chemical_list: D020404:Glycerophospholipids; D008562:Membrane Glycoproteins; D008567:Membranes, Artificial; D009077:Mucins; C025602:dimyristoylphosphatidic acid; D048271:Chitosan