title: Monitoring the endocytosis of magnetic nanoparticles by cells using permanent micro-flux sources.
abstract: Trapping of cells is essential to perform basic handling operations in cell-based microsystems, such as media exchange, concentration, cell isolation and cell sorting. Cell trapping by magnetophoresis typically requires cell labeling with magnetic nanoparticles. Here we report on endocytotic uptake of 100 nm magnetic nanoparticles by Human Embryonic Kidney 293 cells. The attraction of labeled cells by micro-magnet arrays characterised by very high magnetic field gradients (≤10⁶ T/m) was studied as a function of labeling conditions (nanoparticle concentration in the extracellular medium, incubation time). The threshold incubation conditions for effective magnetophoretic trapping were established. This simple technique may be exploited to minimise the quantity of magnetic nanoparticles needed for efficient cell trapping, thus reducing stress or nanoparticle-mediated toxicity. Nanoparticle internalization into cells was confirmed using both confocal and Transmission Electron Microscopy (TEM).
authors: Ampère Laboratory, CNRS-Université Claude Bernard Lyon 1-Ecole Centrale de Lyon, 69134 Ecully, France. osman.osman@ec-lyon.fr
authors: O
authors: O
authors: Osman
authors: L F
authors: LF
authors: Zanini
authors: M
authors: M
authors: Frénéa-Robin
authors: F
authors: F
authors: Dumas-Bouchiat
authors: N M
authors: NM
authors: Dempsey
authors: G
authors: G
authors: Reyne
authors: F
authors: F
authors: Buret
authors: N
authors: N
authors: Haddour
mesh_terms: D004705:Endocytosis / Q000502:physiology*; D057809:HEK293 Cells; D006801:Humans; D008280:Magnetics; D018613:Microscopy, Confocal; D046529:Microscopy, Electron, Transmission; D053758:Nanoparticles / Q000008:administration & dosage / Q000737:chemistry*