title: Combined atomic force microscopy and optical microscopy measurements as a method to investigate particle uptake by cells.
abstract: We propose a combination of atomic force microscopy (AFM) and optical microscopy for the investigation of particle uptake by cells. Positively and negatively charged polymer microcapsules were chosen as model particles, because their interaction with cells had already been investigated in detail. AFM measurements allowed the recording of adhesion forces on a single-molecule level. Due to the micrometer size of the capsules, the number of ingested capsules could be counted by optical microscopy. The combination of both methods allowed combined measurement of the adhesion forces and the uptake rate for the same model particle. As a demonstration of this system, the correlation between the adhesion of positively or negatively charged polymer microcapsules onto cell surfaces and the uptake of these microcapsules by cells has been investigated for several cell lines. As is to be expected, we find a correlation between both processes, which is in agreement with adsorption-dependent uptake of the polymer microcapsules by cells.
authors.affiliation: Physics Department and Center for Nanoscience, Ludwig Maximilians Universität München, 80799 Munich, Germany.
authors.forename: Almudena
authors.initials: A
authors.lastname: Muñoz Javier
authors.forename: Oliver
authors.initials: O
authors.lastname: Kreft
authors.forename: Alicia
authors.initials: A
authors.lastname: Piera Alberola
authors.forename: Christian
authors.initials: C
authors.lastname: Kirchner
authors.forename: Bernd
authors.initials: B
authors.lastname: Zebli
authors.forename: Andrei S
authors.initials: AS
authors.lastname: Susha
authors.forename: Elias
authors.initials: E
authors.lastname: Horn
authors.forename: Susanne
authors.initials: S
authors.lastname: Kempter
authors.forename: Andre G
authors.initials: AG
authors.lastname: Skirtach
authors.forename: Andrey L
authors.initials: AL
authors.lastname: Rogach
authors.forename: Joachim
authors.initials: J
authors.lastname: Rädler
authors.forename: Gleb B
authors.initials: GB
authors.lastname: Sukhorukov
authors.forename: Martin
authors.initials: M
authors.lastname: Benoit
authors.forename: Wolfgang J
authors.initials: WJ
authors.lastname: Parak
mesh_terms: D000268:Adhesiveness; D002462:Cell Membrane / Q000737:chemistry* / Q000378:metabolism*; D018625:Microscopy, Atomic Force / Q000379:methods*; D018613:Microscopy, Confocal / Q000379:methods*; D008863:Microspheres; D009038:Motion; D011108:Polymers / Q000737:chemistry* / Q000493:pharmacokinetics*
chemical_list: D011108:Polymers