title: Imaging interactions of metal oxide nanoparticles with macrophage cells by ultra-high resolution scanning electron microscopy techniques.
abstract: Use of engineered metal oxide nanoparticles in a plethora of biological applications and custom products has warned about some possible dose-dependent cytotoxic effects. Macrophages are key components of the innate immune system used to study possible toxic effects and internalization of different nanoparticulate materials. In this work, ultra-high resolution field emission scanning electron microscopy (FE-SEM) was used to offer new insights into the dynamical processes of interaction of nanomaterials with macrophage cells dosed with different concentrations of metal oxide nanoparticles (CeO(2), TiO(2) and ZnO). The versatility of FE-SEM has allowed obtaining a detailed characterization of processes of adsorption and endocytosis of nanoparticles, by using advanced analytical and imaging techniques on complete unstained uncoated cells, including secondary electron imaging, high-sensitive backscattered electron imaging, X-ray microanalysis and stereoimaging. Low voltage BF/DF-STEM confirmed nanoparticle adsorption and internalization into endosomes of CeO(2) and TiO(2), whereas ZnO develop apoptosis after 24 h of interaction caused by dissolution and invasion of cell nucleus. Ultra-high resolution scanning electron microscopy techniques provided new insights into interactions of inorganic nanoparticles with macrophage cells with high spatial resolution.
authors.affiliation: Department of Physics and Astronomy, The University of Texas at San Antonio, One UTSA Circle, San Antonio, TX 78249, USA. miguel.yacaman@utsa.edu
authors.forename: Germán
authors.initials: G
authors.lastname: Plascencia-Villa
authors.forename: Clarise R
authors.initials: CR
authors.lastname: Starr
authors.forename: Linda S
authors.initials: LS
authors.lastname: Armstrong
authors.forename: Arturo
authors.initials: A
authors.lastname: Ponce
authors.forename: Miguel
authors.initials: M
authors.lastname: José-Yacamán
mesh_terms: D000327:Adsorption; D000818:Animals; D001693:Biological Transport, Active; D002460:Cell Line; D002563:Cerium / Q000633:toxicity; D004577:Electron Probe Microanalysis; D008264:Macrophages / Q000187:drug effects* / Q000378:metabolism / Q000648:ultrastructure*; D053768:Metal Nanoparticles / Q000737:chemistry / Q000633:toxicity* / Q000648:ultrastructure*; D051379:Mice; D008855:Microscopy, Electron, Scanning / Q000379:methods; D017348:Microscopy, Electron, Scanning Transmission; D036103:Nanotechnology; D010316:Particle Size; D014025:Titanium / Q000633:toxicity; D015034:Zinc Oxide / Q000633:toxicity
chemical_list: C009495:titanium dioxide; D002563:Cerium; C030583:ceric oxide; D014025:Titanium; D015034:Zinc Oxide