Formation of annexin-a5 protein/block copolymer micelle complexes : QCM-D and PAGE experiments

The Annexin-A5 (Anx5) protein is a specific marker of the exposure of phosphatidylserine molecules at the surface of cells, which occurs in processes such as apoptosis and platelet activation. Decoration of self-assembled block copolymer nanostructures by Anx5 is of particular interest in micelle-me...

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Publié dans:Langmuir : the ACS journal of surfaces and colloids. - 1985. - 24(2008), 21 vom: 04. Nov., Seite 12189-95
Auteur principal: Schmidt, Vanessa (Auteur)
Autres auteurs: Giacomelli, Cristiano, Gounou, Celine, Lai-Kee-Him, Josephine, Brisson, Alain R, Borsali, Redouane
Format: Article en ligne
Langue:English
Publié: 2008
Accès à la collection:Langmuir : the ACS journal of surfaces and colloids
Sujets:Journal Article Research Support, Non-U.S. Gov't Annexin A5 Micelles Polymers
Description
Résumé:The Annexin-A5 (Anx5) protein is a specific marker of the exposure of phosphatidylserine molecules at the surface of cells, which occurs in processes such as apoptosis and platelet activation. Decoration of self-assembled block copolymer nanostructures by Anx5 is of particular interest in micelle-mediated target drug delivery or in vivo magnetic resonance imaging, the Anx5 imparting (bio)functionality to the system. In this work, the reversible binding of the Anx5 onto polystyrene-b-poly(2-phosphatethyl methacrylate-co-2-hydroxyethyl methacrylate) (PS-b-P(PEMA-co-HEMA)) block copolymer micelles in the presence of Ca2+ ions is described using Quartz crystal microbalance with dissipation monitoring (QCM-D) and polyacrylamide gel electrophoresis (PAGE) analysis. QCM-D experiments confirmed the binding process as well as its reversibility and dependence on the characteristics of macromolecular assemblies, such as the number of phosphonic diacid groups (Pmic) and hydrodynamic diameter (2RH). A linear relationship between the amount of micelles and the amount of protein bound onto the micelle surface until a saturation point was established by QCM-D. The amount of Anx5 bound to PS-b-P(PEMA-co-HEMA) micelles was successfully quantified by PAGE experiments in nondenaturing conditions, which also corroborated that the binding process is mediated by Ca2+ ions. The ability of such surface (bio)-functionalized nanoparticle systems to stabilize and transport hydrophobic loads was highlighted by transmission electron microscopy (TEM) of assemblies with entrapped iron oxide particles
Description:Date Completed 01.12.2008
Date Revised 30.10.2008
published: Print-Electronic
Citation Status MEDLINE
ISSN:1520-5827
DOI:10.1021/la8024815