The effect of surface charge on nonspecific uptake and cytotoxicity of CdSe/ZnS core/shell quantum dots

• Vladimir V. Breus,
• Anna Pietuch,
• Marco Tarantola,
• Thomas Basché and
• Andreas Janshoff

Beilstein J. Nanotechnol. 2015, 6, 281–292, doi:10.3762/bjnano.6.26

• CdSe cores. Pretreatment of cells with pharmacological inhibitors suggested that the uptake of nanoparticles was largely due to receptor-independent endocytosis or spontaneous entry for carboxylated and zwitterionic QDs, while for amine-functionalized particles, formation of vesicles was observed. The

• carried out for 30 min at room temperature, cells were then washed and taken to a microscope. Inhibition of endocytosis MDCKII cells were pretreated with 25 μg/mL chlorpromazine [44], 30 μg/mL 5-(N,N-dimethyl)amiloride [45] and 1 μg/mL filipin III [46] (predissolved in dimethyl sulfoxide 0.5 μg/μL) upon

• overall fluorescent signal by applying standard deviation (for QDs) and averaging (for cells), post-processing algorithms to a 20-frame image sequence obtained during each measurement. CPZ: chlorpromazine (inhibitior of clathrin-mediated endocytosis), DMA: dimethylamyloride hydrochloride (inhibitor of

Tailoring the ligand shell for the control of cellular uptake and optical properties of nanocrystals

• Johannes Ostermann,
• Christian Schmidtke,
• Christopher Wolter,
• Jan-Philip Merkl,
• Hauke Kloust and
• Horst Weller

Beilstein J. Nanotechnol. 2015, 6, 232–242, doi:10.3762/bjnano.6.22

• general (positively or negatively) show a much more efficient adsorption of these proteins needed for the recognition by macrophages [33][34]. Other cell types follow the endocytotic process, which can be receptor mediated or unspecific. For the uptake via endocytosis a positive surface charge has shown

• tested samples and the obtained results are summarized in Table 2. None of the samples showed unspecific adhesion or uptake on A549 cells in serum containing medium after 4 h, although the containers range in a suitable size range between 40 and 80 nm for endocytosis [22]. Even the positively charged

Mechanical properties of MDCK II cells exposed to gold nanorods

• Anna Pietuch,
• Bastian Rouven Brückner,
• David Schneider,
• Marco Tarantola,
• Christina Rosman,
• Carsten Sönnichsen and
• Andreas Janshoff

Beilstein J. Nanotechnol. 2015, 6, 223–231, doi:10.3762/bjnano.6.21

• fluorescence and dark-field microscopy. Conclusion: We found that cells exposed to CTAB coated gold nanorods display a concentration-dependent stiffening that cannot be explained by the presence of CTAB alone. The stiffening results presumably from endocytosis of particles removing excess membrane area from

• . Although it is conceivable that excessive endocytosis leads to a loss of excess surface area the collapse of the plasma membrane on the elastic and considerably stiff actomyosin cortex is also important to explain the mechanical response. Therefore, we will base the following discussion mainly on the

• wrapped by the plasma membrane and thereby consuming all excess surface area. A reduction of surface area immediately leads to apparent cell stiffening at larger strains. Enforced endocytosis leads to a decrease in overall membrane area that causes increased resistance against area dilatation. Pre-stress

Caveolin-1 and CDC42 mediated endocytosis of silica-coated iron oxide nanoparticles in HeLa cells

• Nils Bohmer and
• Andreas Jordan

Beilstein J. Nanotechnol. 2015, 6, 167–176, doi:10.3762/bjnano.6.16

• line. Cells were transfected with specific siRNAs against Caveolin-1, Dynamin 2, Flotillin-1, Clathrin, PIP5Kα and CDC42. Knockdown of Caveolin-1 reduces endocytosis of superparamagnetic iron oxide nanoparticles (SPIONs) and silica-coated iron oxide nanoparticles (SCIONs) between 23 and 41%, depending

• on the surface characteristics of the nanoparticles and the experimental design. Knockdown of CDC42 showed a 46% decrease of the internalization of PEGylated SPIONs within 24 h incubation time. Knockdown of Dynamin 2, Flotillin-1, Clathrin and PIP5Kα caused no or only minor effects. Hence endocytosis

• in HeLa cells of iron oxide nanoparticles, used in this study, is mainly mediated by Caveolin-1 and CDC42. It is shown here for the first time, which proteins of the endocytotic pathway mediate the endocytosis of silica-coated iron oxide nanoparticles in HeLa cells in vitro. In future studies more

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

• CAM has been studied by SCFS. It was shown by SCFS that collagen I binding integrins down-regulate the avidity of fibronectin binding integrins by an increased endocytosis in HeLa cells [30]. The classical SCFS setup, where the adhesion of a cantilever-bound cell to a substrate is probed, has a

Synthesis of boron nitride nanotubes and their applications

• Saban Kalay,
• Zehra Yilmaz,
• Ozlem Sen,
• Melis Emanet,
• Emine Kazanc and
• Mustafa Çulha

Beilstein J. Nanotechnol. 2015, 6, 84–102, doi:10.3762/bjnano.6.9

• addition, the authors evaluated the toxicity of BNNTs according to the cell type and endocytosis ability of the cells. In particular, RAW 264.7 had high endocytosis capability as compared to A549 and 3T3-L1 cell types, and HEK293 showed low endocytosis capability. The results showed that the BNNTs slightly

• related to the cell type and the ability to perform endocytosis [77]. The morphology and viability of the GC–BNNTs-exposed HUVECs cells were also investigated [71]. The cells were incubated at increasing concentrations of GC–BNNTs for 48 and 72 h. The cell morphology and cell viability by amido black

Mammalian cell growth on gold nanoparticle-decorated substrates is influenced by the nanoparticle coating

• Christina Rosman,
• Sebastien Pierrat,
• Marco Tarantola,
• David Schneider,
• Eva Sunnick,
• Andreas Janshoff and
• Carsten Sönnichsen

Beilstein J. Nanotechnol. 2014, 5, 2479–2488, doi:10.3762/bjnano.5.257

• with the negatively charged membrane [21][22], and to the sedimentation behavior of the particles which is related to their colloidal stability under physiological conditions [33]. The uptake was likely caused by non-specific endocytosis or macropinocytosis. Therefore, we expected an even stronger

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

• models and indicate that these models have to be extended in order to capture the interaction between nanomaterials and biological membranes correctly. Keywords: cells; endocytosis; engulfment; fission; gel phase; giant unilamellar lipid vesicles (GUV); lipid membranes; liquid phase; nanoparticle

• small nanoparticles can directly penetrate cell and model membranes [7][8], particles significantly larger than the membrane thickness (3–4 nm) are usually taken up by endocytosis [9][10]. The physical aspects of an interaction between cell membranes and nanoparticles are still not well understood

• . Especially the dependence of the uptake efficiency on the particle size is still an important topic [11][12]. Usually, a complex cell machinery is involved in endocytosis. However, particle uptake including the engulfment by the membrane has also been reported for red blood cells, which are known for not

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

• intravenous injection mostly by liver and spleen macrophages and is retained there for more than two weeks [26]. In contrast to other cells, macrophages express scavenger receptor A on their surface, which mediates endocytosis of diverse ligands including modified low density lipoproteins and which has been

• implicated in the development of atherosclerosis [27]. In vitro studies showed that this receptor is engaged in the internalization of negatively charged ResovistTM, a SPIO of 20–60 nm in size, by human macrophages via clathrin-mediated endocytosis. Hence, the uptake of negatively charged nanoparticles of

• surface of immune cells. In contrast, monocytic leukemia cells internalize nanoparticles by endocytosis. Also in vivo, intravenously injected negatively charged particles accumulate mainly in the liver, known to harbour macrophages of the reticuloendothelial system named Kupffer cells. In contrast

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

• Technology (KIT), 76131 Karlsruhe, Germany Department of Physics, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA 10.3762/bjnano.5.248 Abstract Engineered nanomaterials are known to enter human cells, often via active endocytosis. Mechanistic details of the interactions between

• 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

• , especially in view of possible implications regarding biosafety and biomedical applications of nanomaterials [1][2][3][4][5]. Because NPs have sizes similar to those of biological molecules and assemblies such as proteins or viruses, they are able to invade cells by hijacking the cellular endocytosis

Anticancer efficacy of a supramolecular complex of a 2-diethylaminoethyl–dextran–MMA graft copolymer and paclitaxel used as an artificial enzyme

• Yasuhiko Onishi,
• Yuki Eshita,
• Rui-Cheng Ji,
• Masayasu Onishi,
• Takashi Kobayashi,
• Masaaki Mizuno,
• Jun Yoshida and
• Naoji Kubota

Beilstein J. Nanotechnol. 2014, 5, 2293–2307, doi:10.3762/bjnano.5.238

• , it is suggested that the condensed DNA, which is taken into the cell by endocytosis, is protected from decomposition within the cell and its penetration of the nuclear membrane is also increased [11]. In addition, DDMC is considered to be more stable than DEAE–dextran to the action of the dextran

• -degrading enzyme dextransucrase. The polymer micelle of DDMC forms a complex with DNA, undergoes endocytosis, and a small proportion of the complex is transported to the nucleus. However, analysis of gene expression by using DDMC/DNA has revealed that the majority of the complex is found not in the nucleus

• difficult to induce a nuclear shift, and the majority of gene expression from a DDMC/DNA complex may be outside of the nucleus after endocytosis, except during cell division. The introduction of a shift in location is considered an effect of the drug in the DDMC/PTX complex. ATP-binding cassette

Nanoencapsulation of ultra-small superparamagnetic particles of iron oxide into human serum albumin nanoparticles

• Matthias G. Wacker,
• Mahmut Altinok,
• Stephan Urfels and
• Johann Bauer

Beilstein J. Nanotechnol. 2014, 5, 2259–2266, doi:10.3762/bjnano.5.235

• tumors due to the enhanced permeability and retention effect [5]. While circulating through the blood stream, these colloids undergo an opsonization by the immune system followed by endocytosis into macrophages. Particles of greater diameters are rapidly cleared from the plasma and smaller colloidal

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

• through clathrin-dependent endocytosis and by macropinocytosis and that silver agglomerates were formed in the cytoplasm following the uptake of these nanoparticles [11]. There is a general consensus that dissolved silver ions are responsible for the majority of the biological effects on various cells and

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

• adsorption and desorption can vary widely. A NP covered by a protein adsorption layer is disguised and, therefore, the initial encounter between the NP and a cell, which may trigger the endocytosis machinery by activating specific receptors [17], is governed by the properties of the protein layer rather than

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

• biological media (i.e., in the presence of proteins) the surface of silver nanoparticles is rapidly coated by a protein corona that influences their physicochemical and biological properties including cellular uptake. Silver nanoparticles are taken up by cell-type specific endocytosis pathways as

• such as macropinocytosis, clathrin- and caveolin-mediated endocytosis, and clathrin- and caveolin-independent endocytosis [81][82][83]. Other possible mechanisms such as receptor-mediated diffusion through membrane pores and passive uptake by van der Waals or steric interactions (summarized as adhesive

• interactions) have been suggested [84]. As we have reported, silver nanoparticles were mostly taken up by hMSC through clathrin-dependent endocytosis and macropinocytosis but not through caveolin-dependent endocytosis, as shown by flow cytometry (scattergram analysis) [77]. From the literature it is known that

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

• as dark, approximately 20 nm-diameter particles. It is known that a cell can engulf nanoscale extracellular matter by endocytosis and formation of endosomes [32][33][34][35]. Hence, examination by TEM will not only focus on the localization of intracellular PLLA nanoparticles, but will contain

• . For example, the endosome in Figure 5C may originate from the endocytosis of a single magnetite nanocrystal from the incubation dispersion. However, this is the only intracellular endosome we could find that contains exclusively one single magnetite particle. Thus, endosomal PLLA NPs with magnetite

• (observed by the increase of free magnetite in Figure 6) starts already within the first 24 h after endocytosis. In correlation with the CLSM localization of the PLLA particles, the early endosomes are more or less homogeneously distributed over the intracellular cytoplasm (Figure 2A). A specific

Carbon-based smart nanomaterials in biomedicine and neuroengineering

• Antonina M. Monaco and
• Michele Giugliano

Beilstein J. Nanotechnol. 2014, 5, 1849–1863, doi:10.3762/bjnano.5.196

• key aspect for biological applications of NDs. Vaijayanthimala and colleagues [75] reported that cellular uptake was strictly related to the surface functionalisation of NDs and that it took place through clathrin-mediated, energy-dependent, endocytosis processes. Schrand et al. [76] also investigated

In vitro and in vivo interactions of selected nanoparticles with rodent serum proteins and their consequences in biokinetics

• Wolfgang G. Kreyling,
• Stefanie Fertsch-Gapp,
• Martin Schäffler,
• Blair D. Johnston,
• Nadine Haberl,
• Christian Pfeiffer,
• Jörg Diendorf,
• Carsten Schleh,
• Stephanie Hirn,
• Manuela Semmler-Behnke,
• Matthias Epple and
• Wolfgang J. Parak

Beilstein J. Nanotechnol. 2014, 5, 1699–1711, doi:10.3762/bjnano.5.180

• of the PEG shell. Our in vitro studies clearly demonstrated the rapid binding of serum proteins to AuNP. This is likely reflected in the in vivo biokinetics results found after intravenous injection which led to a predominant accumulation in the liver and Kupffer cell endocytosis. Yet, the fact that

• epithelial lung lining fluid containing 0.9% NaCl the instillate was spread out and diluted such that Ag+ ions formed AgCl, which precipitated and possibly formed nano-sized AgCl particles [27]. These AgCl nanoparticles also underwent endocytosis in the lung epithelium. Subsequently they were dissolved

Different endocytotic uptake mechanisms for nanoparticles in epithelial cells and macrophages

• Dagmar A. Kuhn,
• Dimitri Vanhecke,
• Benjamin Michen,
• Fabian Blank,
• Peter Gehr,
• Alke Petri-Fink and
• Barbara Rothen-Rutishauser

Beilstein J. Nanotechnol. 2014, 5, 1625–1636, doi:10.3762/bjnano.5.174

• mechanisms, that is, phagocytosis, macropinocytosis, clathrin- and caveolin-mediated endocytosis, were investigated using a mouse macrophage (J774A.1) and a human alveolar epithelial type II cell line (A549). In order to deduce the involved pathway in nanoparticle uptake, selected inhibitors specific for one

• suggested that macropinocytosis and phagocytosis, as well as clathrin-mediated endocytosis, play a crucial role. The uptake of 40 nm nanoparticles in alveolar epithelial A549 cells was inhibited after depletion of cholesterol in the plasma membrane (preventing caveolin-mediated endocytosis) and inhibition

• of clathrin-coated vesicles (preventing clathrin-mediated endocytosis). Our data showed that a combination of several distinguishable endocytotic uptake mechanisms are involved in the uptake of 40 nm polystyrene nanoparticles in both the macrophage and epithelial cell line. Keywords: cell lines

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

• routes of cellular endocytosis. While some evidence exists to support the direct membrane translocation of a select number of NP materials (typically partly hydrophobic and very small, as discussed later) the overwhelming evidence to date supports endocytosis as the common route of NP uptake. Thus, once

• NPs are associated to the outer cell plasma membrane they are typically internalized by endocytosis [39][40]. While a variety of different endocytotic pathways exist, which can be quite different in detail (to appreciate the complexity of endocytosis, we refer the reader to the review by Iversen et al

• (cf. Figure 4). Inside those intracellular vesicles the NPs are in an environment (acidic pH, enzymes) completely different from that in the cytosol (cf. Figure 5). Endocytosis and the endosomal escape dilemma have to be taken into account in particular concerning the delivery applications of NPs, in

Protein-coated pH-responsive gold nanoparticles: Microwave-assisted synthesis and surface charge-dependent anticancer activity

• Dickson Joseph,
• Nisha Tyagi,
• Christian Geckeler and
• Kurt E.Geckeler

Beilstein J. Nanotechnol. 2014, 5, 1452–1462, doi:10.3762/bjnano.5.158

• the attached charged particles through endocytosis or other methods [55]. Because of their higher positive surface charge, HIS-AuNPs are easily internalized by cells, after which they cause cell death. A recent report suggests that the interior of lysosomes possesses an acidic pH (pH 4–5), and it

• charged nanoparticles are formed that binds randomly to the cationic sites, which then undergoes endocytosis [59]. In this study, exposure to OVA-AuNPs resulted in a high cell viability due to the poor ability of the nanoparticles to internalize into the cells because of their low level of cellular

The cell-type specific uptake of polymer-coated or micelle-embedded QDs and SPIOs does not provoke an acute pro-inflammatory response in the liver

• Markus Heine,
• Alexander Bartelt,
• Oliver T. Bruns,
• Denise Bargheer,
• Artur Giemsa,
• Barbara Freund,
• Ludger Scheja,
• Christian Waurisch,
• Alexander Eychmüller,
• Rudolph Reimer,
• Horst Weller,
• Peter Nielsen and
• Joerg Heeren

Beilstein J. Nanotechnol. 2014, 5, 1432–1440, doi:10.3762/bjnano.5.155

• canonical lipoprotein receptor-mediated apolipoprotein E-dependent endocytosis into hepatocytes. Future studies by using radiolabelled QDs are needed to quantify the precise contribution of different hepatic cell types for QDs-micelles uptake. However, only 5–10% of liver cells are Kupffer cells [25][33

Nanodiamond-DGEA peptide conjugates for enhanced delivery of doxorubicin to prostate cancer

• Amanee D Salaam,
• Patrick Hwang,
• Roberus McIntosh,
• Hadiyah N Green,
• Ho-Wook Jun and
• Derrick Dean

Beilstein J. Nanotechnol. 2014, 5, 937–945, doi:10.3762/bjnano.5.107

• size and zeta potential are particularly important for drug delivery applications as they give representations of size limitations and potential colloidal stability issues of a system. NDs permeate the cell membrane by endocytosis [20][36][37]. Through this pathway, NDs can effectively deliver drugs

Manipulation of isolated brain nerve terminals by an external magnetic field using D-mannose-coated γ-Fe₂O₃ nano-sized particles and assessment of their effects on glutamate transport

• Tatiana Borisova,
• Natalia Krisanova,
• Arsenii Borуsov,
• Roman Sivko,
• Ludmila Ostapchenko,
• Michal Babic and
• Daniel Horak

Beilstein J. Nanotechnol. 2014, 5, 778–788, doi:10.3762/bjnano.5.90

• level, nanoparticles can pass through the plasma membrane of the cells by means of endocytosis [27]. Opposite point of view argues that uptake of nanoparticles into the cells does not occur by endocytic processes, but rather by diffusion or adhesive interactions [28]. In this study, we have presented a

Near-infrared dye loaded polymeric nanoparticles for cancer imaging and therapy and cellular response after laser-induced heating

• Tingjun Lei,
• Alicia Fernandez-Fernandez,
• Romila Manchanda,
• Yen-Chih Huang and
• Anthony J. McGoron

Beilstein J. Nanotechnol. 2014, 5, 313–322, doi:10.3762/bjnano.5.35

• the cells through an endocytosis pathway (Supporting Information File 1, Figure S5). Calculated image ratio values, R, from the fluorescence microscope images show that the NP formulation produces a higher intracellular fluorescence intensity (R = 3.75 ± 0.54) (mean ± SD) than the free dye (R = 2.89