Increasing throughput of AFM-based single cell adhesion measurements through multisubstrate surfaces

• Miao Yu,
• Nico Strohmeyer,
• Jinghe Wang,
• Daniel J. Müller and
• Jonne Helenius

Beilstein J. Nanotechnol. 2015, 6, 157–166, doi:10.3762/bjnano.6.15

• replaced after characterizing 4 cells on each coating. If a cell showed morphological changes during the experiments, it was discarded. Adhesion forces were extracted from force–distance curves using JPK data processing software. Fluorescence microscopy and UV–vis spectroscopy Fluorescence microscopy was

Multifunctional layered magnetic composites

• Maria Siglreitmeier,
• Baohu Wu,
• Tina Kollmann,
• Martin Neubauer,
• Gergely Nagy,
• Dietmar Schwahn,
• Vitaliy Pipich,
• Damien Faivre,
• Dirk Zahn,
• Andreas Fery and
• Helmut Cölfen

Beilstein J. Nanotechnol. 2015, 6, 134–148, doi:10.3762/bjnano.6.13

• confirmed by TGA measurements, and that the structure of the demineralized nacre organic matrix has not significantly changed compared with the original nacre. Nacre organic matrix – Light microscopy and fluorescence microscopy Original nacre (Haliotis laevigata) used for materials synthesis was analyzed by

• . Laptev (University of Konstanz) for performing the SQUID measurements, Dr. Joachim Hentschel and Lauretta Nejedli for microtomy services (Electron Microscopy Center at the University of Konstanz). Fluorescence microscopy images were acquired at the Bioimaging Center at the University of Konstanz (BIC

Intake of silica nanoparticles by giant lipid vesicles: influence of particle size and thermodynamic membrane state

• Florian G. Strobl,
• Florian Seitz,
• Christoph Westerhausen,
• Armin Reller,
• Adriano A. Torrano,
• Christoph Bräuchle,
• Achim Wixforth and
• Matthias F. Schneider

Beilstein J. Nanotechnol. 2014, 5, 2468–2478, doi:10.3762/bjnano.5.256

• Experimental section for definition) is Cs ≈ 10 m2/L in all experiments. The interaction of particles and vesicles is then observed by fluorescence microscopy. Uptake of particles induced by double layer force To enable an uptake as described before, there must be a sufficient attractive force between the

• experiment. This procedure is not necessary in the case of gel-phase vesicles. A suitable GUV, i.e., an isolated unilamellar vesicle without membrane inclusions, was chosen for further examination by fluorescence microscopy (Zeiss Axiovert 200M). The nanoparticles dispersed in glucose medium were applied to

Poly(styrene)/oligo(fluorene)-intercalated fluoromica hybrids: synthesis, characterization and self-assembly

• Giuseppe Leone,
• Francesco Galeotti,
• William Porzio,
• Guido Scavia,
• Luisa Barba,
• Gianmichele Arrighetti,
• Giovanni Ricci,
• Chiara Botta and
• Umberto Giovanella

Beilstein J. Nanotechnol. 2014, 5, 2450–2458, doi:10.3762/bjnano.5.254

• silicates, while the polymer matrix is completely dark, which confirms that the whole amount of the emissive TF is confined in between the fluoromica layers. The AFM images reported as inset of Figure 4a–c confirm the large-scale morphology observed by fluorescence microscopy and reveal an organization and

• spectra of PT5 (a), PT15 (b), PT30 (c) and TF films (d). Fluorescence microscopy image, corresponding AFM magnification X,Y = 20 µm (inset) and cluster profile of PT5 (a) PT15 (b) and PT30 (c) films. d) AFM detail of a typical cluster. (a–c) Microscopy images of films of PT5, PT15 and PT30 cast under

• breath figure conditions. (d–f) Fluorescence microscopy images of PT5, PT15 and PT30 films prepared under the same conditions, after the addition of free TF (0.4% w/w). (g) Highly ordered microporous film of PT30 after optimization of parameters. (h) AFM view of a 10 × 10 µm2 area of the same film. All

Synthesis and characterization of fluorescence-labelled silica core-shell and noble metal-decorated ceria nanoparticles

• Rudolf Herrmann,
• Markus Rennhak and
• Armin Reller

Beilstein J. Nanotechnol. 2014, 5, 2413–2423, doi:10.3762/bjnano.5.251

• intense peak at 540 nm (to be followed by fluorescence microscopy), a secondary peak at 575 nm, and a shoulder at 630 nm, together with a tail down to ca. 700 nm. Both MPD and BPD could be attached to Stöber type [9] silica NP [5] which were successfully applied in biological investigations [10][11], as

Functionalized polystyrene nanoparticles as a platform for studying bio–nano interactions

• Cornelia Loos,
• Tatiana Syrovets,
• Anna Musyanovych,
• Volker Mailänder,
• Katharina Landfester,
• G. Ulrich Nienhaus and
• Thomas Simmet

Beilstein J. Nanotechnol. 2014, 5, 2403–2412, doi:10.3762/bjnano.5.250

• either PS-COOH or PS-NH2 (each at 100 µg/mL) for 72 h, analyzed by using fluorescence microscopy and quantified by using ImageJ. The graphs show the amounts of apoptotic (annexin V+) and late apoptotic or necrotic (propidium iodide+) cells. Camptothecin: positive control. Results are mean ± SEM, n = 3

Nanoparticle interactions with live cells: Quantitative fluorescence microscopy of nanoparticle size effects

• Li Shang,
• Karin Nienhaus,
• Xiue Jiang,
• Linxiao Yang,
• Katharina Landfester,
• Volker Mailänder,
• Thomas Simmet and
• G. Ulrich Nienhaus

Beilstein J. Nanotechnol. 2014, 5, 2388–2397, doi:10.3762/bjnano.5.248

• machinery in order to trigger the subsequent internalization. Keywords: cell membrane; endocytosis; fluorescence microscopy; nanoparticle; size effect; Introduction Understanding the interaction between engineered nanomaterials and living matter has attracted increasing attention in recent years

• [24][25][26][27]. Because of the inevitable protein corona formation in any biological environment, one has also to be aware that experiments on cultured cells may yield results different from in vivo studies. Over the past few years, we have used spinning disk confocal fluorescence microscopy to

• varying concentrations (1–10 nM), fluorescence microscopy was performed over time courses of typically 1–2 h. Quantitative analysis of the image sequences revealed that the amount of NPs associated with the membrane scaled, within the error, with the NP concentration in solution (Figure 3a). The fraction

Interaction of dermatologically relevant nanoparticles with skin cells and skin

• Annika Vogt,
• Fiorenza Rancan,
• Sebastian Ahlberg,
• Berouz Nazemi,
• Chun Sik Choe,
• Maxim E. Darvin,
• Sabrina Hadam,
• Ulrike Blume-Peytavi,
• Kateryna Loza,
• Jörg Diendorf,
• Matthias Epple,
• Christina Graf,
• Eckart Rühl,
• Martina C. Meinke and
• Jürgen Lademann

Beilstein J. Nanotechnol. 2014, 5, 2363–2373, doi:10.3762/bjnano.5.245

• chose in order to investigate skin penetration of topically applied silica particles (Figure 1a). Here, conventional fluorescence microscopy of skin sections yielded no evidence for the penetration of 42–300 nm fluorescent silica particles in excised human skin. The data are in accordance with

• cellular uptake (a). Labeling of particles with fluorescein enabled the visualization of particle accumulation on skin sections and in hair follicle openings by using fluorescence microscopy (b). However, single particles on the skin surface could only be visualized after preparation of silica particles

• from skin tissue pretreated with fluorescent 42 nm particles identified a small percentage of cells associated with particles (d, boxed areas in representative flow cytometry images). Single cell fluorescence microscopy confirmed the presence of cell-associated particles that are highly suggestive for

Coating with luminal gut-constituents alters adherence of nanoparticles to intestinal epithelial cells

• Heike Sinnecker,
• Katrin Ramaker and
• Andreas Frey

Beilstein J. Nanotechnol. 2014, 5, 2308–2315, doi:10.3762/bjnano.5.239

• cells was analyzed via fluorescence microscopy (Figure 2). Quantitative results were obtained by comparing fluorescence intensities using image analysis software, whereby values obtained with untreated NPs (control without protein pretreatment) were set to 100% fluorescence intensity. We found that, in

• -2 cells in the presence of proteinaceous compounds. Differently sized NPs, without or with pretreatment with different protein mixtures, were incubated with Caco-2 cells. After extensive washing, particle adherence to and/or uptake by the cells was determined by fluorescence microscopy. Values were

• . Either differently sized NPs or Caco-2 cells were preincubated with buffer or with different proteins before interacting with each other. Particle adherence to the cells was determined by fluorescence microscopy. Values were normalized to intensities obtained with untreated cells and particles (mean + SD

Effect of silver nanoparticles on human mesenchymal stem cell differentiation

• Christina Sengstock,
• Jörg Diendorf,
• Matthias Epple,
• Thomas A. Schildhauer and
• Manfred Köller

Beilstein J. Nanotechnol. 2014, 5, 2058–2069, doi:10.3762/bjnano.5.214

• added. After 14 d or 21 d, the cells were washed twice with RPMI and incubated with Calcein-AM (1 µM) at 37 °C for 30 min under cell culture conditions. Subsequently, the adherent cells were washed again with RPMI and analyzed by fluorescence microscopy (Olympus MVX10, Olympus, Hamburg, Germany

• Bodipy493/503 for 15 min. Subsequently, cells were washed twice with distilled water, and the adipogenic differentiation rates of hMSCs were assessed with an EVOS xl core light microscope (PEQLAB Biotechnologie GMBH, Erlangen, Germany) or by fluorescence microscopy (Olympus BX63, Olympus, Hamburg, Germany

• of nano-silver by hMSCs and the influence of nanoparticulate or ionic silver on the viability and differentiation potential of these cells. The viability and adipogenic, osteogenic and chondrogenic differentiation potential were examined qualitatively and quantitatively through light and fluorescence

Effects of surface functionalization on the adsorption of human serum albumin onto nanoparticles – a fluorescence correlation spectroscopy study

• Pauline Maffre,
• Stefan Brandholt,
• Karin Nienhaus,
• Li Shang,
• Wolfgang J. Parak and
• G. Ulrich Nienhaus

Beilstein J. Nanotechnol. 2014, 5, 2036–2047, doi:10.3762/bjnano.5.212

• Succinylation and amination (Figure 6) of HSA (Sigma-Aldrich, Milwaukee, WI) were performed according to published protocols [22][49]. Fluorescence microscopy Sample preparation 10 min prior to the FCS measurement, 10 µL of the QD solution (≈1 nM) were added to 10 µL of protein solution (at varying

Carbon nano-onions (multi-layer fullerenes): chemistry and applications

• Juergen Bartelmess and
• Silvia Giordani

Beilstein J. Nanotechnol. 2014, 5, 1980–1998, doi:10.3762/bjnano.5.207

• fluorescent CNO nanomaterial that accumulated in the organisms and could be observed by fluorescence microscopy. Control experiments with non-CNO fed specimens were performed, excluding auto-fluorescence as reason for the observed luminescence of the organisms. Following their initial work describing in vivo

PVP-coated, negatively charged silver nanoparticles: A multi-center study of their physicochemical characteristics, cell culture and in vivo experiments

• Sebastian Ahlberg,
• Alexandra Antonopulos,
• Jörg Diendorf,
• Ralf Dringen,
• Matthias Epple,
• Rebekka Flöck,
• Wolfgang Goedecke,
• Christina Graf,
• Nadine Haberl,
• Jens Helmlinger,
• Fabian Herzog,
• Frederike Heuer,
• Stephanie Hirn,
• Christian Johannes,
• Stefanie Kittler,
• Manfred Köller,
• Katrin Korn,
• Wolfgang G. Kreyling,
• Fritz Krombach,
• Jürgen Lademann,
• Kateryna Loza,
• Eva M. Luther,
• Marcelina Malissek,
• Martina C. Meinke,
• Daniel Nordmeyer,
• Anne Pailliart,
• Jörg Raabe,
• Fiorenza Rancan,
• Barbara Rothen-Rutishauser,
• Eckart Rühl,
• Carsten Schleh,
• Andreas Seibel,
• Christina Sengstock,
• Lennart Treuel,
• Annika Vogt,
• Katrin Weber and
• Reinhard Zellner

Beilstein J. Nanotechnol. 2014, 5, 1944–1965, doi:10.3762/bjnano.5.205

• demonstrated for hMSC, primary T-cells, primary monocytes, and astrocytes. A visualization of particles inside cells is possible by X-ray microscopy, fluorescence microscopy, and combined FIB/SEM analysis. By staining organelles, their localization inside the cell can be additionally determined. While primary

• dissolution process in cells (including the localization of low concentrations of small nanoparticles as well as silver ions) imaging at the Ag L3,2 edges is a promising option for future work. Focused ion beam (FIB) and optical microscopy (phase contrast microscopy; fluorescence microscopy; confocal laser

• cultured with 20 µg mL−1 silver nanoparticles at 37 °C for 24 h. Phase microscopy (Figure 9A) and fluorescence microscopy (Figure 9B) images were taken of identical cell areas (merge, Figure 9C). Agglomerated silver nanoparticles were detected in perinuclear regions (Figure 9A; black arrow). As shown in

Imaging the intracellular degradation of biodegradable polymer nanoparticles

• Anne-Kathrin Barthel,
• Martin Dass,
• Melanie Dröge,
• Jens-Michael Cramer,
• Daniela Baumann,
• Markus Urban,
• Katharina Landfester,
• Volker Mailänder and
• Ingo Lieberwirth

Beilstein J. Nanotechnol. 2014, 5, 1905–1917, doi:10.3762/bjnano.5.201

• )-encapsulated ovalbumin nanoparticles into macrophage cells [14]. They used DQ ovalbumin, which is a self-quenched ovalbumin conjugate that exhibits fluorescence after proteolytic degradation. Following the degradation process, they employed confocal fluorescence microscopy and found that the degradation rate

Biocompatibility of cerium dioxide and silicon dioxide nanoparticles with endothelial cells

• Claudia Strobel,
• Martin Förster and
• Ingrid Hilger

Beilstein J. Nanotechnol. 2014, 5, 1795–1807, doi:10.3762/bjnano.5.190

• with Alexa-Fluor®-546 Phalloidin (5 units/ml; 20 min at room temperature; Life Technologies GmbH, Germany), and the cell nuclei with Hoechst 33258 (0.2 µg/mL; AppliChem GmbH, Germany). The cells were embedded in Permafluor® (Thermo Fisher, USA) and analyzed via fluorescence microscopy (Evos fl; PEQLAB

Influence of surface-modified maghemite nanoparticles on in vitro survival of human stem cells

• Michal Babič,
• Daniel Horák,
• Lyubov L. Lukash,
• Tetiana A. Ruban,
• Yurii N. Kolomiets,
• Svitlana P. Shpylova and
• Oksana A. Grypych

Beilstein J. Nanotechnol. 2014, 5, 1732–1737, doi:10.3762/bjnano.5.183

• cells (in terms of optical density) in cultures in presence and absence of the particles (control) were compared. Fluorescence microscopy Polypeptides of cell cytoplasm were stained with 0.001% ThR aqueous solution for 2–5 min and observed by fluorescence microscopy under excitation at 510 nm and

Precise quantification of silica and ceria nanoparticle uptake revealed by 3D fluorescence microscopy

• Adriano A. Torrano and
• Christoph Bräuchle

Beilstein J. Nanotechnol. 2014, 5, 1616–1624, doi:10.3762/bjnano.5.173

• combines the advantages of confocal fluorescence microscopy with fast and precise semi-automatic image analysis. In this work we present how this method was applied to investigate the impact of 310 nm silica nanoparticles on human vascular endothelial cells (HUVEC) in comparison to a cancer cell line

• unusual uptake behavior could be cell division. Keywords: ceria nanoparticles; fluorescence microscopy; image analysis; nanotoxicology; silica nanoparticles; Introduction Measuring the interaction between nanoparticles and cells is a mandatory step for the investigation of nanoparticles designed for

• of a culture well and nanoparticles are added to this culture to interact with the cells. Fluorescence microscopy is commonly the method of choice to visualize this interaction because it can be performed on live cells with high spatial and temporal resolution. Finally, outcomes of the uptake process

In vitro interaction of colloidal nanoparticles with mammalian cells: What have we learned thus far?

• Moritz Nazarenus,
• Qian Zhang,
• Mahmoud G. Soliman,
• Pablo del Pino,
• Beatriz Pelaz,
• Susana Carregal-Romero,
• Joanna Rejman,
• Barbara Rothen-Rutishauser,
• Martin J. D. Clift,
• Reinhard Zellner,
• G. Ulrich Nienhaus,
• James B. Delehanty,
• Igor L. Medintz and
• Wolfgang J. Parak

Beilstein J. Nanotechnol. 2014, 5, 1477–1490, doi:10.3762/bjnano.5.161

• microscopy (TEM), in which also the structure of the intracellular organelles can be resolved (cf. Figure 6), or with fluorescence microscopy, in which the intracellular organelles have been co-stained with a fluorescent marker [65][66][67]. However, these data have to be interpreted carefully. In particular

• . Scheme depicting the different mechanisms of cellular endocytosis. Reproduced with permission from [41]. Copyright (2011) Elsevier. Fluorescence microscopy image showing the granular structure of internalized NPs inside A549 lung cancer cells (two types of iron oxide NPs with different surface chemistry

The protein corona protects against size- and dose-dependent toxicity of amorphous silica nanoparticles

• Dominic Docter,
• Christoph Bantz,
• Dana Westmeier,
• Hajo J. Galla,
• Qiangbin Wang,
• James C. Kirkpatrick,
• Peter Nielsen,
• Michael Maskos and
• Roland H. Stauber

Beilstein J. Nanotechnol. 2014, 5, 1380–1392, doi:10.3762/bjnano.5.151

• enzymatic/biochemical assays [30], we, here, present an automated high-throughput microscopy based approach, generally applicable to reliably and reproducibly assessing the cell vitality following exposure to nanomaterial. By uUsing the ArrayScan® VTI fluorescence microscopy imaging platform [31], we

• of live and dead cells by fluorescence microscopy. Only living cells are able to convert the virtually non-fluorescent cell-permeable calcein-AM to the intensely fluorescent calcein, resulting in an intense uniform green fluorescence of living cells. EthD-1 is however excluded by the intact plasma

• standardized studies. To this end, high-throughput testing is a key strategy to fill current gaps in knowledge and to systematically build nanomaterial structure–activity relationships (nanoSAR) [30]. By using adequate fluorescence microscopy imaging platforms, dual-color fluorescence cell vitality assay

PEGylated versus non-PEGylated magnetic nanoparticles as camptothecin delivery system

• Paula M. Castillo,
• Mario de la Mata,
• Maria F. Casula,
• José A. Sánchez-Alcázar and
• Ana P. Zaderenko

Beilstein J. Nanotechnol. 2014, 5, 1312–1319, doi:10.3762/bjnano.5.144

• text. Infrared spectra of USM[CPT] (top, blue solid line), CPT (center, grey dotted line) and USM-PEG[CPT] (bottom, red solid line). A: Fluorescence microscopy images of H460 cell cultures: control (left); with bare USM (middle); with PEGylated USM (right). B: Fluorescence microscopy images of the H460

Model systems for studying cell adhesion and biomimetic actin networks

• Dorothea Brüggemann,
• Johannes P. Frohnmayer and
• Joachim P. Spatz

Beilstein J. Nanotechnol. 2014, 5, 1193–1202, doi:10.3762/bjnano.5.131

• ]. Erb and Engel later showed by cryoelectron and fluorescence microscopy that activated integrin αIIbβ3 reconstituted into liposomes and planar bilayers was present in a nonclustered state and was equally distributed within the membrane. When fibrinogen was bound to the proteolipid structures the

• minimal cell system. The scale bar represents 10 μm (Reprinted with permission from [54]. Copyright (2009) Elsevier Ltd.) Dependence of actin/α-actinin network structures on the vesicle size. The 3D reconstructions of networks by confocal fluorescence microscopy (at a temperature of 4 °C). (A) Examples of

The softening of human bladder cancer cells happens at an early stage of the malignancy process

• Jorge R. Ramos,
• Joanna Pabijan,
• Ricardo Garcia and
• Malgorzata Lekka

Beilstein J. Nanotechnol. 2014, 5, 447–457, doi:10.3762/bjnano.5.52

• show that in human bladder cancer cells, both the expression level of actin (in particular, β-actin) and its 3D-organization in the probing volume govern the elastic properties. The organization of actin filaments present on the surface of a cell as probed by AFM and fluorescence microscopy is not

• types of malignant cells, HTB-9 (grade II, carcinoma) and HT-1376 (grade III, carcinoma) do not show the presence of stress fibers. These results are consistent with fluorescence microscopy images of actin filaments stained by using phalloidin that was labeled with Alexa Fluor 488 dye (Figure 2, panels

• ) showed various organizations of the actin cytoskeleton as observed by fluorescence microscopy. In non-malignant HCV29 cells, both short actin filaments and stress fibers are visible. Similarly, both structures are present in cancerous T24 cells (transitional cell carcinoma). The two other cancerous cells

Extracellular biosynthesis of gadolinium oxide (Gd₂O₃) nanoparticles, their biodistribution and bioconjugation with the chemically modified anticancer drug taxol

• Shadab Ali Khan,
• Sanjay Gambhir and
• Absar Ahmad

Beilstein J. Nanotechnol. 2014, 5, 249–257, doi:10.3762/bjnano.5.27

• ) and X-ray photoemission spectroscopy (XPS). The Gd2O3–taxol bioconjugate was confirmed by UV–vis spectroscopy and fluorescence microscopy and was purified by using high performance liquid chromatography (HPLC). Keywords: bioconjugation; biodistribution; gadolinium oxide; humicola sp; transmission

• -1601 PC) operated at a resolution of 1 nm. Fluorescence microscopy Fluorescence measurements of Gd2O3–taxol bioconjugate were carried out by using a Perkin Elmer LS-50B spectrofluorimeter with a slit width of 7 nm for both monochromators and a scan speed of 100 nm/min. Purification of Gd2O3–taxol

Apertureless scanning near-field optical microscopy of sparsely labeled tobacco mosaic viruses and the intermediate filament desmin

• Alexander Harder,
• Mareike Dieding,
• Volker Walhorn,
• Sven Degenhard,
• Andreas Brodehl,
• Christina Wege,
• Hendrik Milting and
• Dario Anselmetti

Beilstein J. Nanotechnol. 2013, 4, 510–516, doi:10.3762/bjnano.4.60

• versatile and extensively used in applications ranging from nanotechnology to life sciences. In fluorescence microscopy luminescent dyes serve as position markers. Moreover, they can be used as active reporters of their local vicinity. The dipolar coupling of the tip with the incident light and the

• ; fluorescence microscopy; Introduction Scanning near-field optical microscopy (SNOM) provides sub-wavelength optical resolution [1]. The sample is excited by the strongly confined near-field at the tip apex, which is induced by the dipolar coupling between the incident light and the probe. Moreover, coupling

Porous polymer coatings as substrates for the formation of high-fidelity micropatterns by quill-like pens

• Michael Hirtz,
• Marcus Lyon,
• Wenqian Feng,
• Andrea E. Holmes,
• Harald Fuchs and
• Pavel A. Levkin

Beilstein J. Nanotechnol. 2013, 4, 377–384, doi:10.3762/bjnano.4.44

• . Comparison of printed phloxine B solution on different substrates. Fluorescence microscopy images of the printed solution on (a) paper, (b) nylon, (c) porous HEMA polymer film, and (d) nitrocellulose. Corresponding in situ bright-field images with delivery microchannel cantilever still in place for (e) paper

• containing BSA (green), respectively (inset shows a fluorescence microscopy image of one of the pristine bromophenol blue patterns, scale bar equals 100 µm). Supporting Information Supporting Information File 4: Figures S1 and S2. Acknowledgements This work was carried out with the support of the Karlsruhe