title: Mass spectrometry and imaging analysis of nanoparticle-containing vesicles provide a mechanistic insight into cellular trafficking.
abstract: Rational design of nanocarriers for drug delivery approaches requires an unbiased knowledge of uptake mechanisms and intracellular trafficking pathways. Here we dissected these processes using a quantitative proteomics approach. We isolated intracellular vesicles containing superparamagnetic iron oxide polystyrene nanoparticles and analyzed their protein composition by label-free quantitative mass spectrometry. The proteomic snapshot of organelle marker proteins revealed that an atypical macropinocytic-like mechanism mediated the entry of nanoparticles. We show that the entry mechanism is controlled by actin reorganization, atypical macropinocytic signaling, and ADP-ribosylation factor 1. Additionally, our proteomics data demonstrated a central role for multivesicular bodies and multilamellar lysosomes in trafficking and final nanoparticle storage. This was confirmed by confocal microscopy and cryo-TEM measurements. By quantitatively analyzing the protein composition of nanoparticle-containing vesicles, our study clearly defines the routes of nanoparticle entry, intracellular trafficking, and the proteomic milieu of a nanoparticle-containing vesicle.
authors.affiliation: Max Planck Institute for Polymer Research , Ackermannweg 10, 55128 Mainz, Germany.
authors.forename: Daniel
authors.initials: D
authors.lastname: Hofmann
authors.forename: Stefan
authors.initials: S
authors.lastname: Tenzer
authors.forename: Markus B
authors.initials: MB
authors.lastname: Bannwarth
authors.forename: Claudia
authors.initials: C
authors.lastname: Messerschmidt
authors.forename: Simone-Franziska
authors.initials: SF
authors.lastname: Glaser
authors.forename: Hansjörg
authors.initials: H
authors.lastname: Schild
authors.forename: Katharina
authors.initials: K
authors.lastname: Landfester
authors.forename: Volker
authors.initials: V
authors.lastname: Mailänder
mesh_terms: D001692:Biological Transport; D004705:Endocytosis; D013058:Mass Spectrometry / Q000379:methods*; D046529:Microscopy, Electron, Transmission; D053758:Nanoparticles; D040901:Proteomics
keywords: endocytosis; endosomes; intracellular trafficking; macropinocytosis-like; magnetic purification; multilamellar lysosomes; multivesicular bodies; nanoparticles; vesicles