title: Applications of biosensing atomic force microscopy in monitoring drug and nanoparticle delivery.
abstract: BACKGROUND
  The therapeutic effects of medicinal drugs not only depend on their properties, but also on effective transport to the target receptor. Here we highlight recent developments in this discipline and show applications of atomic force microscopy (AFM) that enable us to track the effects of drugs and the effectiveness of nanoparticle delivery at the single molecule level.
  
  
  METHODS
  Physiological AFM imaging enables visualization of topographical changes to cells as a result of drug exposure and allows observation of cellular responses that yield morphological changes. When we upgrade the regular measuring tip to a molecular biosensor, it enables investigation of functional changes at the molecular level via single molecule force spectroscopy.
  
  
  CONCLUSIONS
  Biosensing AFM techniques have generated powerful tools to monitor drug delivery in (living) cells. While technical developments in actual AFM methods have simplified measurements at relevant physiological conditions, understanding both the biological and technical background is still a crucial factor. However, due to its potential impact, we expect the number of application-based biosensing AFM techniques to further increase in the near future.
authors.affiliation: University of Kiel, Institute of Materials Science Biocompatible Nanomaterials , Kaiserstr.2, 24143 Kiel , Germany.
authors.forename: Constanze
authors.initials: C
authors.lastname: Lamprecht
authors.forename: Peter
authors.initials: P
authors.lastname: Hinterdorfer
authors.forename: Andreas
authors.initials: A
authors.lastname: Ebner
mesh_terms: D000818:Animals; D015374:Biosensing Techniques; D016503:Drug Delivery Systems / Q000379:methods*; D016903:Drug Monitoring / Q000379:methods*; D006801:Humans; D018625:Microscopy, Atomic Force; D053758:Nanoparticles; D036103:Nanotechnology
keywords: atomic force microscopy; drug delivery; force spectroscopy; molecular interactions; nanoparticle; single molecules; tip functionalization