Name: in situ detection and single cell quantification of metal oxide nanoparticles using nuclear microprobe analysis
Uploaded: 2018-02-03T13:00:00
Description: Watch this Scientific Journal Video about In Situ Detection and Single Cell Quantification of Metal Oxide Nanoparticles Using Nuclear Microprobe Analysis at JoVE.com

We thank Serge Borderes for directing and editing of the video. The French National Research Agency supports the research program TITANIUMS (ANR CES 2010, n&#176; CESA 009 01). The CNRS and the European Community as an Integrating activity provided the "Support of Public and Industrial Research Using Ion Beam Technology (SPIRIT)" under the EC contract n&#176; 227012. This work has been supported by Marie Curie Actions - Initial Training Networks (ITN) as an "Integrating Activity Supporting Postgraduate Research with Internships in Industry and Training Excellence" (SPRITE, D1.3) under EC contract no. 317169. The C'NANO Grand Sud Ouest and the Region Aquitaine support the research program TOX-NANO (n&#176;20111201003) and the research program POPRA (n&#176; 14006636-034).

1. Sample Holder Preparation
<ol>
	<li>Sample holder design and preparation
	<ol>
		<li>Manufacture a sample holder by drilling a 5 mm x 5 mm square in a 1-mm thick PEEK frame.</li>
		<li>Clean by rinsing with ethanol 70% (v/v) and keep in sterile plates until ready to use. 
		Note. A sample holder appropriate for cell culture and cell handling is required. It needs to be designed for cell culturing, in vitro observations with optical microscopy, and nuclear microprobe analysis and imagin...

<ol>
	<li>Krug, H. F., Wick, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nanotoxicology:+An+Interdisciplinary+Challenge.">Nanotoxicology: An Interdisciplinary Challenge.</a> Angew. Chem. Int. Ed. 50 (6), 1260-1278 (2011).</li><li>Van Hove, M. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=From+surface+science+to+nanotechnology.">From surface science to nanotechnology.</a> Catalysis Today. 113 (3-4), 133-140 (2006).</li><li>Le Trequesser, Q., Seznec, H., Delville, M. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Functionalized+nanomaterials:+their+use+as+contrast+agents+in+bioimaging:+mono-+and+multimodal+approaches.">Functionalized nanomaterials: their use as contrast agents in bioimaging: mono- and multimodal approaches.</a> Nanotox. Rev. 2 (2), 125-169 (2013).</li><li>Oberdorster, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Safety+assessment+for+nanotechnology+and+nanomedicine:+concepts+of+nanotoxicology.">Safety assessment for nanotechnology and nanomedicine: concepts of nanotoxicology.</a> J. Int. Med. , 89-105 (2009).</li><li>Savolainen, K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nanotechnologies,+engineered+nanomaterials+and+occupational+health+and+safety+-+A+review.">Nanotechnologies, engineered nanomaterials and occupational health and safety - A review.</a> Saf. Sci. 48 (8), 957-963 (2010).</li><li>Savolainen, K., Alenius, H., Norppa, H., Pylkkanen, L., Tuomi, T., Kasper, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Risk+assessment+of+engineered+nanomaterials+and+nanotechnologies+-+A+review.">Risk assessment of engineered nanomaterials and nanotechnologies - A review.</a> Toxicol. 269 (2-3), 92-104 (2010).</li><li>Arora, S., Rajwade, J. M., Paknikar, K. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nanotoxicology+and+in+vitro+studies:+The+need+of+the+hour.">Nanotoxicology and in vitro studies: The need of the hour.</a> Toxicol. . Appl. Pharm. 258 (2), 151-165 (2012).</li><li>Donaldson, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Resolving+the+nanoparticles+paradox.">Resolving the nanoparticles paradox.</a> Future Med. 1 (2), 229-234 (2006).</li><li>Schaumann, G. E., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Understanding+the+fate+and+biological+effects+of+Ag-+and+TiO2-nanoparticles+in+the+environment:+The+quest+for+advanced+analytics+and+interdisciplinary+concepts.">Understanding the fate and biological effects of Ag- and TiO2-nanoparticles in the environment: The quest for advanced analytics and interdisciplinary concepts.</a> Sci Total Environ. 535, 3-19 (2014).</li><li>Olesik, J. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Inductively Coupled Plasma Mass Spectrometers. Treatise on Geochemistry. , (2014).</li><li>Krystek, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+review+on+approaches+to+bio-distribution+studies+about+gold+and+silver+engineered+nanoparticles+by+inductively+coupled+plasma+mass+spectrometry.">A review on approaches to bio-distribution studies about gold and silver engineered nanoparticles by inductively coupled plasma mass spectrometry.</a> Microchem. J. 105 (November 2011), 39-43 (2012).</li><li>Le Trequesser, Q., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Multimodal+correlative+microscopy+for+in+situ+detection+and+quantification+of+chemical+elements+in+biological+specimens.+Applications+to+nanotoxicology.">Multimodal correlative microscopy for in situ detection and quantification of chemical elements in biological specimens. Applications to nanotoxicology.</a> J .Chem. Biol. 8 (4), 159-167 (2015).</li><li>Le Trequesser, Q., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Single+cell+in+situ+detection+and+quantification+of+metal+oxide+nanoparticles+using+multimodal+correlative+microscopy.">Single cell in situ detection and quantification of metal oxide nanoparticles using multimodal correlative microscopy.</a> Anal. Chem. 86 (15), 7311-7319 (2014).</li><li>Ackermann, C. M., Lee, S., Chang, C. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Analytical+Methods+for+Imaging+Metals+in+Biology:+From+Transition+Metal+Metabolism+to+Transition+Metal+Signaling.">Analytical Methods for Imaging Metals in Biology: From Transition Metal Metabolism to Transition Metal Signaling.</a> Anal. Chem. 89 (1), 22-41 (2017).</li><li>Legin, A. A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=NanoSIMS+combined+with+fluorescence+microscopy+as+a+tool+for+subcellular+imaging+of+isotopically+labeled+platinum-based+anticancer+drugs.">NanoSIMS combined with fluorescence microscopy as a tool for subcellular imaging of isotopically labeled platinum-based anticancer drugs.</a> Chem. Sci. 5, 3135 (2014).</li><li>Lanni, E. J., Rubakhin, S. S., Sweedler, J. V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mass+spectrometry+imaging+and+profiling+of+single+cells.">Mass spectrometry imaging and profiling of single cells.</a> J. Proteomics. 75 (16), 5036-5051 (2012).</li><li>Waypa, G. B., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hypoxia+triggers+subcellular+compartmental+redox+signaling+in+vascular+smooth+muscle+cells.">Hypoxia triggers subcellular compartmental redox signaling in vascular smooth muscle cells.</a> Circ. Res. 106 (3), 526-535 (2010).</li><li>Dooley, C. T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Imaging+Dynamic+Redox+Changes+in+Mammalian+Cells+with+Green+Fluorescent+Protein+Indicators.">Imaging Dynamic Redox Changes in Mammalian Cells with Green Fluorescent Protein Indicators.</a> J. Biol. Chem. 279 (21), 22284-22293 (2004).</li><li>Hanson, G. T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Investigating+Mitochondrial+Redox+Potential+with+Redox-sensitive+Green+Fluorescent+Protein+Indicators.">Investigating Mitochondrial Redox Potential with Redox-sensitive Green Fluorescent Protein Indicators.</a> J. Biol. Chem. 279 (13), 13044-13053 (2004).</li><li>Chen, X., Mao, S. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Titanium+dioxide+nanomaterials:+Synthesis,+properties,+modifications+and+applications.">Titanium dioxide nanomaterials: Synthesis, properties, modifications and applications.</a> Chem. Rev. 107 (7), 2891-2959 (2007).</li><li>Simon, M., Barberet, P., Delville, M. H., Moretto, P., Seznec, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Titanium+dioxide+nanoparticles+induced+intracellular+calcium+homeostasis+modi+fi+cation+in+primary+human+keratinocytes.+Towards+an+in+vitro+explanation+of+titanium+dioxide+nanoparticles+toxicity.">Titanium dioxide nanoparticles induced intracellular calcium homeostasis modi fi cation in primary human keratinocytes. Towards an in vitro explanation of titanium dioxide nanoparticles toxicity.</a> Nanotox. 5 (June), 125-139 (2011).</li><li>Sorieul, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+ion+beam+facility+for+multidisciplinary+research.">An ion beam facility for multidisciplinary research.</a> Nucl. Instr. Meth. Phys. Res., B. 332, 68-73 (2014).</li><li>Barberet, P., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=First+results+obtained+using+the+CENBG+nanobeam+line:+Performances+and+applications.">First results obtained using the CENBG nanobeam line: Performances and applications.</a> Nucl Instr Meth Phys Res B. 269 (20), 2163-2167 (2011).</li><li>Dev&#232;s, G., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+ImageJ+plugin+for+ion+beam+imaging+and+data+processing+at+AIFIRA+facility.">An ImageJ plugin for ion beam imaging and data processing at AIFIRA facility.</a> Nucl. Instr. Meth. Phys. Res. B. 348, 62-67 (2015).</li><li>Mayer, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> SIMNRA User's Guide, Report IPP 9/113. , (1997).</li><li>Campbell, J. L., Boyd, N. I., Grassi, N., Bonnick, P., Maxwell, J. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Guelph+PIXE+software+package+IV.">The Guelph PIXE software package IV.</a> Nucl. Instr. Meth. Phys. Res. B. 268 (20), 3356-3363 (2010).</li><li>Yu, K., Chang, S., Park, S. J., Lim, J., Lee, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Titanium+Dioxide+Nanoparticles+Induce+Endoplasmic+Reticulum+Stress-Mediated+Autophagic+Cell+Death+via+Mitochondria-+Associated+Endoplasmic+Reticulum+Membrane+Disruption+in+Normal+Lung+Cells.">Titanium Dioxide Nanoparticles Induce Endoplasmic Reticulum Stress-Mediated Autophagic Cell Death via Mitochondria- Associated Endoplasmic Reticulum Membrane Disruption in Normal Lung Cells.</a> PLoS ONE. , 1-17 (2015).</li></ol>

We describe a method providing useful information beyond what is possible with other imaging techniques, especially at the subcellular level. In addition to its imaging ability, nuclear microprobe analysis also offers possibilities of quantification of chemical elements entering in the composition of a biological sample. In the present work, we studied human cell populations and focused down to the analysis of a chosen region of interest based on a single cell exposed to TiO2 NPs. Its combination with other te...

Cellular homeostasis is determined by the uptake control, assimilation, and intracellular localization of different trace elements (ions, metals, exogenous inorganic compounds). These components are frequently in the form of traces, but nevertheless may have a considerable impact in the system physiology. Thus, the study of cell biochemistry in both normal and pathological/stressed situations is a key-step towards an overall understanding of cellular metabolic mechanisms. Therefore, the development of imaging and analytical techniques enabling the investigation of intracellular chemical abundances, structural organization and their related metabolic functions becomes necessary. Very few methods are able to provide an in situ quantitative piece of information concerning the overall chemical nature of a given sample. Apart from methods analyzing samples in the bulk form, in situ analyses consider biological samples in their integrality without losing mass and structural information, thereby preserving their constituent chemicals (trace elements and ions) and proteins. Furthermore, as the nanosciences continue to develop, improved imaging and analytical methods for environmental monitoring at the cellular scale will be necessary to observe and quantify nano-object behaviors and interactions.1
Nanoparticles (NPs) have been defined as objects exhibiting at least one facial dimension in the range 1 and 100 nm.2 Due to their particular physicochemical properties, NPs are extensively used in industry. NPs are employed in bio-applications and in nanomedicine.3,4 Despite the numerous physicochemical characteristics of NPs, they may generate some risks of adverse effects on human health and environment. These risks can be induced by both prolonged and repetitive exposures at various concentration levels and this has not yet been clearly established.5,6,7,8 In particular, the fate of NPs inside cells and the associated cellular responses are, to date, not fully described. This is in part due to the scarcity of methods that allow the detection and quantification of internalized NPs in a single cell.9
The classical analytical tools used to estimate the cellular dose of nanoparticles are microscopies, mass spectrometry (MS), inductively coupled plasma MS (ICP-MS)10,11 and liquid chromatography MS (LC-MS), but they only provide useful information at the macroscopic scale. None of them can provide a precise evaluation of the subcellular NPs content nor the NPs distribution without the use of fractionation methods. A systematic assessment of the dose-response is thus impossible with these methods, as opposed to methods based on atomic spectroscopy such as nuclear microprobe analysis12,13, synchrotron X-ray fluorescence microscopy14, and Secondary Ion Mass Spectrometry (SIMS).15,16 These methods are particularly interesting as they complement observations made using fluorescence microscopy, especially when NPs cannot be labeled with fluorescent molecules and are thus studied in their native state. To some extent, even when NPs are grafted with fluorophores, (i) quantification remains difficult because the tagging level per NP is unknown and (ii) the chemical modification of the NP surface may modify its cellular distribution.
In this article, we focus on a method based on a combination of nuclear microprobe techniques aiming at imaging the morphology and elemental composition of biological specimens in major, minor, and trace concentrations.
Nuclear microprobe analysis proves to be particularly suitable for the measurement of trace chemical elements in biological tissues. Both the beam lateral resolution (0.3 to 1 &#181;m) and sensitivity in chemical element detection (from 1 to 10 &#181;g.g-1 dry mass) are well suited for studies at the cellular level. Nuclear microprobe techniques are based on particles detection (photons, electrons, ions) emitted after the ion beam (typically running at MeV energies) interacts with atoms present in the sample. Interactions occurring in cells are mainly: 1) excitation/ionization of atoms followed by an emission of photons after atoms return to their fundamental state; and 2) diffusion of incoming particles leading to change in their energy and direction. The measurement of emitted particle energy allowsthe identification of atoms involved in the interaction. To perform mapping of elements, the ion microbeam is repeatedly scanned over the sample surface, often over an area of about 100 by 100 &#181;m2 containing several cells. Emitted particles are detected and their energy is recorded for each beam position. Sorting of particles according to the beam position, thus identifying the structure responsible for the emission of such particles is the aim of data treatment. Here, we precisely describe an approach based on fluorescence microscopy and nuclear microprobe analysis to detect as well as to quantify exogenous NPs at the cellular and sub-cellular scales, in order to investigate the consequences of NP interactions with living systems. We shall particularly focus on the opportunities offered by this method in terms of in situ quantification of titanium dioxide nanoparticles (TiO2 NPs) aggregates at the subcellular level.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>Cell culture</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>U2OS</td>
			<td>ATCC, LGC STANDARDS</td>
			<td>ATCC HTB-96</td>
			<td></td>
		</tr>
		<tr>
			<td>Medium MCCOY 5A w/o L-Glutamine</td>
			<td>Dominique DUTSCHER</td>
			<td>L0211-500</td>
			<td></td>
		</tr>
		<tr>
			<td>FBS 500 mL</td>
			<td>Dominique DUTSCHER</td>
			<td>500105U</td>
			<td></td>
		</tr>
		<tr>
			<td>Penicillin/Streptomycin&#160;</td>
			<td>ThermoFisher Scientific</td>
			<td>11548876</td>
			<td></td>
		</tr>
		<tr>
			<td>&#160;L-Glutamine 200 mM, 100 mL&#160;</td>
			<td>Invitrogen</td>
			<td>25030024</td>
			<td></td>
		</tr>
		<tr>
			<td>Geneticin,&#160; 20 mL</td>
			<td>ThermoFisher Scientific</td>
			<td>10092772</td>
			<td></td>
		</tr>
		<tr>
			<td>Trypsin-EDTA 0.25% (v/v)&#160; 500 mL</td>
			<td>ThermoFisher Scientific</td>
			<td>11570626</td>
			<td></td>
		</tr>
		<tr>
			<td>Viromer Red</td>
			<td>Lipocalyx</td>
			<td>VR-01LB-01</td>
			<td></td>
		</tr>
		<tr>
			<td>Matrix-roGFP Plasmid</td>
			<td>AddGene</td>
			<td>#49437</td>
			<td></td>
		</tr>
		<tr>
			<td>Hoechst 33342</td>
			<td>ThermoFisher Scientific</td>
			<td>H3570</td>
			<td>Handle with care</td>
		</tr>
		<tr>
			<td>NPs preparation</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>TiO2 P25 AEROXIDE</td>
			<td>Degussa/Evonik</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Tetramethylrhodamine isothiocyanate (TRITC)</td>
			<td>SIGMA-ALDRICH</td>
			<td>T3163</td>
			<td>Surface modification of NPs</td>
		</tr>
		<tr>
			<td>Sample preparation</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Polycarbonate foil</td>
			<td>Goodfellow</td>
			<td>CT301020</td>
			<td></td>
		</tr>
		<tr>
			<td>Polyether Ether Ketone support (PEEK)</td>
			<td>Matechplast</td>
			<td>A-239-4047</td>
			<td></td>
		</tr>
		<tr>
			<td>Ethanol, ACS absolute</td>
			<td>SIGMA-ALDRICH</td>
			<td>02860-6x1L</td>
			<td></td>
		</tr>
		<tr>
			<td>Chlorform, Anhydrous, 99%</td>
			<td>SIGMA-ALDRICH</td>
			<td>372978-1L&#160;</td>
			<td>Caution toxic</td>
		</tr>
		<tr>
			<td>Formvar 100 g</td>
			<td>Agar Scientific</td>
			<td>AGR1201</td>
			<td>Harmful. Use in a concentration of 10 &#181;g per mL of chloroform</td>
		</tr>
		<tr>
			<td>NaOH</td>
			<td>SIGMA-ALDRICH</td>
			<td>S5881-500G</td>
			<td></td>
		</tr>
		<tr>
			<td>Sample fixation</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Powder, 95% Paraformaldehyde</td>
			<td>SIGMA-ALDRICH</td>
			<td>158127-500G</td>
			<td>Caution toxic. Use as a 4% solution in PBS</td>
		</tr>
		<tr>
			<td>PBS (pH 7.4, without Ca2+ and Mg2+)</td>
			<td>ThermoFisher Scientific</td>
			<td>11503387</td>
			<td></td>
		</tr>
		<tr>
			<td>Prolong Gold Antifade Reagent</td>
			<td>ThermoFisher Scientific</td>
			<td>P36934</td>
			<td></td>
		</tr>
		<tr>
			<td>Triton X-100</td>
			<td>SIGMA-ALDRICH</td>
			<td>93443</td>
			<td>Harmful</td>
		</tr>
		<tr>
			<td>Sample cryofixation</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Liquid nitrogen</td>
			<td>air liquids sante</td>
			<td></td>
			<td>Harmful</td>
		</tr>
		<tr>
			<td>Methylbutane &#62;=99%</td>
			<td>SIGMA-ALDRICH</td>
			<td>&#160;M32631-1L</td>
			<td>Caution toxic</td>
		</tr>
		<tr>
			<td>Aluminium transfer plate</td>
			<td>Home-made</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Distilled and deionized water</td>
			<td>Home-made</td>
			<td></td>
			<td>Produced in the laboratory using the Barnstead Smart2Pure system</td>
		</tr>
		<tr>
			<td>Parafilm</td>
			<td>VWR</td>
			<td>52858-000</td>
			<td></td>
		</tr>
		<tr>
			<td>Equipment</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Barnstead Smart2Pure</td>
			<td>ThermoFisher Scientific</td>
			<td>50129870</td>
			<td></td>
		</tr>
		<tr>
			<td>Biosafety bench, class II</td>
			<td>ThermoFisher Scientific</td>
			<td>MSC-Advantage</td>
			<td></td>
		</tr>
		<tr>
			<td>TC20 automated cell counter</td>
			<td>Biorad</td>
			<td>145-0102SP</td>
			<td></td>
		</tr>
		<tr>
			<td>Counting slides 2 wells</td>
			<td>Biorad</td>
			<td>1450016</td>
			<td></td>
		</tr>
		<tr>
			<td>PIPS detector, 25 mm2, 12 keV energy resolution @5.5 MeV</td>
			<td>Canberra&#160;</td>
			<td>PD25-12-100AM</td>
			<td></td>
		</tr>
		<tr>
			<td>High-resolution Si (Li) solid-state detector,145-eVenergy resolution, @Mn-K&#945;</td>
			<td>Oxford Instruments</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Everhart-Thornley type secondary electron detector (SED)&#160;</td>
			<td>Orsay Physics</td>
			<td>1-SED</td>
			<td></td>
		</tr>
		<tr>
			<td>XRF Calibration Standard sodium or Chlorine as NaCl</td>
			<td>Micromatter</td>
			<td>34381</td>
			<td></td>
		</tr>
		<tr>
			<td>XRF Calibration Standard Magnesium as MgF2</td>
			<td>Micromatter</td>
			<td>34382</td>
			<td></td>
		</tr>
		<tr>
			<td>XRF Calibration Standard Aluminium as Al metal</td>
			<td>Micromatter</td>
			<td>34383</td>
			<td></td>
		</tr>
		<tr>
			<td>XRF Calibration Standard Silicon as SiO</td>
			<td>Micromatter</td>
			<td>34384</td>
			<td></td>
		</tr>
		<tr>
			<td>XRF Calibration Standard Sulfur as CuSx</td>
			<td>Micromatter</td>
			<td>34385</td>
			<td></td>
		</tr>
		<tr>
			<td>XRF Calibration Standard Calcium as CaF2</td>
			<td>Micromatter</td>
			<td>34387</td>
			<td></td>
		</tr>
		<tr>
			<td>XRF Calibration Standard Titanium as Ti metal</td>
			<td>Micromatter</td>
			<td>34388</td>
			<td></td>
		</tr>
		<tr>
			<td>XRF Calibration Standard Iron as Fe metal</td>
			<td>Micromatter</td>
			<td>34389</td>
			<td></td>
		</tr>
		<tr>
			<td>Sonicator 750W</td>
			<td>Sonics Materials</td>
			<td>11743619</td>
			<td></td>
		</tr>
		<tr>
			<td>3MM microprobe</td>
			<td>Bioblock scientific</td>
			<td>220-05</td>
			<td></td>
		</tr>
		<tr>
			<td>Lyophilizer in vacuum</td>
			<td>Elexience</td>
			<td>EK3147</td>
			<td></td>
		</tr>
		<tr>
			<td>Optical microscope Zeiss AxioObserver Z1</td>
			<td>Carl Zeiss MicroImaging, GmbH</td>
			<td>431006-9901</td>
			<td></td>
		</tr>
		<tr>
			<td>Motorized stage xy</td>
			<td>Carl Zeiss MicroImaging, GmbH</td>
			<td>432031-9902</td>
			<td></td>
		</tr>
		<tr>
			<td>EC Plan-Neofluar 20X, NA 0.50 Ph2 M27 objective</td>
			<td>Carl Zeiss MicroImaging, GmbH</td>
			<td>420351-9910</td>
			<td></td>
		</tr>
		<tr>
			<td>Plan-Apochromat 63X, NA 1,40 Ph3M27 objective</td>
			<td>Carl Zeiss MicroImaging, GmbH</td>
			<td>420781-9910</td>
			<td></td>
		</tr>
		<tr>
			<td>Zeiss filterset 02</td>
			<td>Carl Zeiss MicroImaging, GmbH</td>
			<td>488002-9901</td>
			<td></td>
		</tr>
		<tr>
			<td>Zeiss filterset 38HE</td>
			<td>Carl Zeiss MicroImaging, GmbH</td>
			<td>489038-9901</td>
			<td></td>
		</tr>
		<tr>
			<td>Zeiss filterset 31</td>
			<td>Carl Zeiss MicroImaging, GmbH</td>
			<td>000000-1031-350</td>
			<td></td>
		</tr>
		<tr>
			<td>Chemical fume hood</td>
			<td>Erlab</td>
			<td>Captair SD321</td>
			<td></td>
		</tr>
		<tr>
			<td>Particle accelerator</td>
			<td>HVEE</td>
			<td>singletron</td>
			<td></td>
		</tr>
		<tr>
			<td>Software</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>ImageJ software</td>
			<td>National Institutes of health, USA</td>
			<td>ImageJ 1.51</td>
			<td></td>
		</tr>
		<tr>
			<td>SimNRA software</td>
			<td>Max-Planck-Institut f&#252;r Plasmaphysik, Germany</td>
			<td>SIMNRA 6.06</td>
			<td></td>
		</tr>
		<tr>
			<td>Gupix software</td>
			<td>Guelph university, Canada</td>
			<td>GUPIXWIN 2.2.4</td>
			<td></td>
		</tr>
	</tbody>
</table>

in situ detection and single cell quantification of metal oxide nanoparticles using nuclear microprobe analysis

Micro-analytical techniques based on chemical element imaging enable the localization and quantification of chemical composition at the cellular level. They offer new possibilities for the characterization of living systems and are particularly appropriate for detecting, localizing and quantifying the presence of metal oxide nanoparticles both in biological specimens and the environment. Indeed, these techniques all meet relevant requirements in terms of (i) sensitivity (from 1 up to 10 &#181;g.g-1 of dry mass), (ii) micrometer range spatial resolution, and (iii) multi-element detection. Given these characteristics, microbeam chemical element imaging can powerfully complement routine imaging techniques such as optical and fluorescence microscopy. This protocol describes how to perform a nuclear microprobe analysis on cultured cells (U2OS) exposed to titanium dioxide nanoparticles. Cells must grow on and be exposed directly in a specially designed sample holder used on the optical microscope and in the nuclear microprobe analysis stages. Plunge-freeze cryogenic fixation of the samples preserves both the cellular organization and the chemical element distribution. Simultaneous nuclear microprobe analysis (scanning transmission ion microscopy, Rutherford backscattering spectrometry and particle induced X-ray emission) performed on the sample provides information about the cellular density, the local distribution of the chemical elements, as well as the cellular content of nanoparticles. There is a growing need for such analytical tools within biology, especially in the emerging context of Nanotoxicology and Nanomedicine for which our comprehension of the interactions between nanoparticles and biological samples must be deepened. In particular, as nuclear microprobe analysis does not require nanoparticles to be labelled, nanoparticle abundances are quantifiable down to the individual cell level in a cell population, independently of their surface state.

Cell culture and fluorescence imaging of fluorescently labeled TiO2 NPs
We designed a sample holder adapted for cell culture, cell handling as well as multimodal analysis. Specifically, it was important that the holder permitted routine optical microscopy as well as nuclear microprobe analysis and imaging. This sample holder is based on a 2-&#181;m thick polycarbonate...

Watch this Scientific Journal Video about In Situ Detection and Single Cell Quantification of Metal Oxide Nanoparticles Using Nuclear Microprobe Analysis at JoVE.com

In Situ Detection and Single Cell Quantification of Metal Oxide Nanoparticles Using Nuclear Microprobe Analysis

We describe a procedure for the detection of chemical elements present in situ in human cells as well as their in vitro quantification. The method is well-suited to any cell type and is particularly useful for quantitative chemical analyses in single cells following in vitro metal oxide nanoparticles exposure.

In Situ Detection and Single Cell Quantification of Metal Oxide Nanoparticles Using Nuclear Microprobe Analysis

Micro-analytical techniques based on chemical element imaging enable the localization and quantification of chemical composition at the cellular level. ...

Research

JoVE Journal

Chemistry

Using Polystyrene-block-poly(acrylic acid)-coated Metal Nanoparticles as Monomers for Their Homo- and Co-polymerization

Using Polystyrene-block-polyacrylic acid-coated Metal Nanoparticles as Monomers for Their Homo- and Co-polymerization

We present a template-free method for &#8220;polymerizing&#8221; nanoparticles into long chains without side branches. A variety of nanoparticles are ...

Reverse Microemulsion-mediated Synthesis of Monometallic and Bimetallic Early Transition Metal Carbide and Nitride Nanoparticles

A reverse microemulsion is used to encapsulate monometallic or bimetallic early transition metal oxide nanoparticles in microporous silica shells. The ...

Generation of Zerovalent Metal Core Nanoparticles Using n-(2-aminoethyl)-3-aminosilanetriol

Generation of Zerovalent Metal Core Nanoparticles Using n-2-aminoethyl-3-aminosilanetriol

In this work, a facile one-pot reaction for the formation of metal nanoparticles in a water solution through the use of ...

Photochemical Oxidative Growth of Iridium Oxide Nanoparticles on CdSe@CdS Nanorods

We demonstrate a procedure for the photochemical oxidative growth of iridium oxide catalysts on the surface of seeded cadmium selenide-cadmium sulfide ...

Sequencing of Plant Wall Heteroxylans Using Enzymic, Chemical (Methylation) and Physical (Mass Spectrometry, Nuclear Magnetic Resonance) Techniques

Sequencing of Plant Wall Heteroxylans Using Enzymic, Chemical Methylation and Physical Mass Spectrometry, Nuclear Magnetic Resonance Techniques

This protocol describes the specific techniques used for the characterization of reducing end (RE) and internal region glycosyl sequence(s) of ...

Aerosol-assisted Chemical Vapor Deposition of Metal Oxide Structures: Zinc Oxide Rods

Whilst columnar zinc oxide (ZnO) structures in the form of rods or wires have been synthesized previously by different liquid- or vapor-phase routes, ...

Microprobe Capillary Electrophoresis Mass Spectrometry for Single-cell Metabolomics in Live Frog (Xenopus laevis) Embryos

Microprobe Capillary Electrophoresis Mass Spectrometry for Single-cell Metabolomics in Live Frog Xenopus laevis Embryos

The quantification of small molecules in single cells raises new potentials for better understanding the basic processes that underlie embryonic ...

Ligand-Mediated Nucleation and Growth of Palladium Metal Nanoparticles

The size, size distribution and stability of colloidal nanoparticles are greatly affected by the presence of capping ligands. Despite the key contribution ...

Solvothermal Synthesis of MIL-96 and UiO-66-NH2 on Atomic Layer Deposited Metal Oxide Coatings on Fiber Mats

Solvothermal Synthesis of MIL-96 and UiO-66-NH2 on Atomic Layer Deposited Metal Oxide Coatings on Fiber Mats

Metal-organic frameworks (MOFs), which contain reactive metal clusters and organic ligands allowing for large porosities and surface areas, have proven ...