title: Nanoscale characterization of vesicle adhesion by normalized total internal reflection fluorescence microscopy.
abstract: We recently proposed a straightforward fluorescence microscopy technique to study adhesion of Giant Unilamellar Vesicles. This technique is based on dual observations which combine epi-fluorescence microscopy and total internal reflection fluorescence (TIRF) microscopy: TIRF images are normalized by epi-fluorescence ones. By this way, it is possible to map the membrane/substrate separation distance with a nanometric resolution, typically ~20 nm, with a maximal working range of 300-400 nm. The purpose of this paper is to demonstrate that this technique is useful to quantify vesicle adhesion from ultra-weak to strong membrane-surface interactions. Thus, we have examined unspecific and specific adhesion conditions. Concerning unspecific adhesion, we have controlled the strength of electrostatic forces between negatively charged vesicles and various functionalized surfaces which exhibit a positive or a negative effective charge. Specific adhesion was highlighted with lock-and-key forces mediated by the well defined biotin/streptavidin recognition.
authors.affiliation: Laboratoire de Nanotechnologie et d'Instrumentation Optique, Institut Charles Delaunay, UMR CNRS 6281, Université de Technologie de Troyes, 12 Rue Marie Curie, CS 42060, 10 004 Troyes Cedex, France.
authors.forename: Marcelina
authors.initials: M
authors.lastname: Cardoso Dos Santos
authors.affiliation: Laboratoire de Nanotechnologie et d'Instrumentation Optique, Institut Charles Delaunay, UMR CNRS 6281, Université de Technologie de Troyes, 12 Rue Marie Curie, CS 42060, 10 004 Troyes Cedex, France. Electronic address: cyrille.vezy@utt.fr.
authors.forename: Cyrille
authors.initials: C
authors.lastname: Vézy
authors.affiliation: Laboratoire de Nanotechnologie et d'Instrumentation Optique, Institut Charles Delaunay, UMR CNRS 6281, Université de Technologie de Troyes, 12 Rue Marie Curie, CS 42060, 10 004 Troyes Cedex, France. Electronic address: rodolphe.jaffiol@utt.fr.
authors.forename: Rodolphe
authors.initials: R
authors.lastname: Jaffiol
mesh_terms: D002448:Cell Adhesion; D002462:Cell Membrane; D008856:Microscopy, Fluorescence / Q000379:methods*; D036103:Nanotechnology; D053835:Unilamellar Liposomes
chemical_list: D053835:Unilamellar Liposomes
keywords: Fluorescence nanoscopy; Membrane–surface interaction; Total internal reflection fluorescence (TIRF); Vesicle adhesion