title: Uptake of fluorescent iron oxide nanoparticles by oligodendroglial OLN-93 cells.
abstract: To investigate the cellular accumulation and intracellular localization of dimercaptosuccinate-coated iron oxide nanoparticles (D-IONPs) in oligodendroglial cells, we have synthesized IONPs that contain the fluorescent dye BODIPY (BP) in their coat (BP-D-IONPs) and have investigated the potential effects of the absence or presence of this dye on the particle uptake by oligodendroglial OLN-93 cells. Fluorescent BP-D-IONPs and non-fluorescent D-IONPs had similar hydrodynamic diameters and ζ-potentials of around 60 nm and -58 mV, respectively, and showed identical colloidal stability in physiological media with increasing particle size and positivation of the ζ-potential in presence of serum. After exposure of oligodendroglial OLN-93 cells to BP-D-IONPs or D-IONPs in the absence of serum, the specific cellular iron content increased strongly to around 1,800 nmol/mg. This strong iron accumulation was lowered for both types of IONPs by around 50 % on exposure of the cells at 4 °C and by around 90 % on incubation in presence of 10 % serum. The accumulation of both D-IONPs and BP-D-IONPs in the absence of serum was not affected by endocytosis inhibitors, whereas in the presence of serum inhibitors of clathrin-dependent endocytosis lowered the particle accumulation by around 50 %. These data demonstrate that oligodendroglial cells efficiently accumulate IONPs by an endocytotic process which is strongly affected by the temperature and the presence of serum and that BP-D-IONPs are a reliable tool to monitor by fluorescence microscopy the uptake and cellular fate of D-IONPs.
authors.affiliation: Center for Biomolecular Interactions Bremen, University of Bremen, PO. Box 330440, 28334, Bremen, Germany.
authors.forename: Charlotte
authors.initials: C
authors.lastname: Petters
authors.forename: Felix
authors.initials: F
authors.lastname: Bulcke
authors.forename: Karsten
authors.initials: K
authors.lastname: Thiel
authors.forename: Ulf
authors.initials: U
authors.lastname: Bickmeyer
authors.forename: Ralf
authors.initials: R
authors.lastname: Dringen
mesh_terms: D000818:Animals; D002460:Cell Line; D004705:Endocytosis; D005290:Ferric Compounds / Q000378:metabolism*; D005456:Fluorescent Dyes / Q000378:metabolism*; D053768:Metal Nanoparticles; D008856:Microscopy, Fluorescence; D009836:Oligodendroglia / Q000378:metabolism*; D010316:Particle Size; D051381:Rats
chemical_list: D005290:Ferric Compounds; D005456:Fluorescent Dyes; C000499:ferric oxide