title: Direct measurement of hydrophobic forces on cell surfaces using AFM.
abstract: Although hydrophobic forces are of great relevance in biological systems, quantifying these forces on complex biosurfaces such as cell surfaces has been difficult owing to the lack of appropriate, ultrasensitive force probes. Here, chemical force microscopy (CFM) with hydrophobic tips was used to measure local hydrophobic forces on organic surfaces and on live bacteria. On organic surfaces, we found an excellent correlation between nanoscale CFM and macroscale wettability measurements, demonstrating the sensitivity of the method toward hydrophobicity and providing novel insight into the nature of hydrophobic forces. Then, we measured hydrophobic forces associated with mycolic acids on the surface of mycobacteria, supporting the notion that these hydrophobic compounds represent an important permeation barrier to drugs.
authors.affiliation: Unité de Chimie des Interfaces, Université Catholique de Louvain, Croix du Sud 2/18, Louvain-La-Neuve, Belgium.
authors.forename: David
authors.initials: D
authors.lastname: Alsteens
authors.forename: Etienne
authors.initials: E
authors.lastname: Dague
authors.forename: Paul G
authors.initials: PG
authors.lastname: Rouxhet
authors.forename: Alain R
authors.initials: AR
authors.lastname: Baulard
authors.forename: Yves F
authors.initials: YF
authors.lastname: Dufrêne
mesh_terms: D001422:Bacterial Adhesion / Q000502:physiology*; D002462:Cell Membrane / Q000737:chemistry / Q000378:metabolism* / Q000648:ultrastructure; D057927:Hydrophobic and Hydrophilic Interactions; D018625:Microscopy, Atomic Force; D009161:Mycobacterium / Q000166:cytology / Q000378:metabolism* / Q000648:ultrastructure; D009171:Mycolic Acids / Q000737:chemistry*; D010539:Permeability; D013499:Surface Properties
chemical_list: D009171:Mycolic Acids