Imaging and Organelle Distribution of Fluorescent InGaP/ZnS Nanoparticles in Glial Cells By: Maik Behrendt, Dusica Maysinger, Ken McDonald, R. Anne McKinney, Ewa Przybytkowski, Marinella G. Sandros Behrendt, M., Sandros, M.G., McKinney, R.A., McDonald, K., Przybytkowski, E., Tabrizian, M., Maysinger, D. (2009). Imaging and organelle distribution of fluorescent InGaP/ZnS nanoparticles in glial cells. Nanomedicine, 4(7), 747-761. doi: 10.2217/nnm.09.64 Made available courtesy of Future Medicine Ltd.: http://dx.doi.org/10.2217/nnm.09.64 ***© Future Medicine Ltd. Reprinted with permission. No further reproduction is authorized without written permission from Future Medicine Ltd. This version of the document is not the version of record. Figures and/or pictures may be missing from this format of the document. *** Abstract: Aim: To assess the effects of oleic acid treatment on subcellular distribution of indium gallium phosphide–zinc sulfide (InGaP/ZnS) nanoparticles in microglia and astrocytes. Materials & methods: The extent of colocalization between the nanoparticles and organelles was assessed by confocal microscopy, spectrofluorometry and cell sorting. Results: Cell treatment with a common fatty acid (oleic acid) within the range of physiological concentrations markedly enhanced the InGaP/ZnS uptake by microglia and afforded their colocalization within lipid droplets/lysosomes but not with mitochondria. Conclusion: These results suggest that the availability of mono-unsaturated fatty acids, such as oleic acid, in different cells could significantly alter nanoparticle uptake and localization, which can in turn affect the functions of cells and tissues coexposed to nanoparticles. Keywords: cell organelles | imaging | lipid droplets | lysosomes | microglia | mitochondria | quantum dots Article: One of the challenges in nanomedicine is the determination of the distribution of nanoparticulate carriers and nanoparticles in the body, as well as in individual cells, in real time [1] . Most of the single cell studies performed to date were done in different cell lines, but studies in primary neural cultures are still relatively sparse [2-6] . The main objective of the present study was to examine the intra-organelle distribution of indium gallium phosphide-zinc sulfide (InGaP/ZnS)- coated nanoparticles in primary neural glial cells obtained from the cortical brain region, and to assess the role of exogenous oleic acid as a putative agent that can influence nanoparticle subcellular distribution. The rationale for selecting InGaP/ZnS nanoparticles is that they have excellent photophysical properties and they are less toxic within a low nanomolar concentration range (1-10 nM) than several other nanoparticles [7,8] . Primary cortical-dispersed mixed culture