Protein corona – from molecular adsorption to physiological complexity

• Lennart Treuel,
• Dominic Docter,
• Michael Maskos and
• Roland H. Stauber

Beilstein J. Nanotechnol. 2015, 6, 857–873, doi:10.3762/bjnano.6.88

• longer circulation times in the blood as well as altered bio-distribution upon injection in mice [155]. Attempts were also made to coat NPs by specific proteins. For example, transferrin, well known to be internalized via its cognate receptor, was used to create a protein corona and study its effect on

• the polymer shell), by live HeLa cells in the presence or absence of human transferrin (TF) and human serum albumin (HSA) in phosphate-buffered saline (PBS) medium. They studied the uptake of the NPs by quantitative confocal fluorescence microscopy. For comparison, they also studied the cellular

• uptake of fluorescently labeled (ca. 1:1 ratio) transferrin and HSA molecules. Whilst transferrin was endocytosed in significant amounts, HSA was barely internalized by HeLa cells under otherwise identical conditions. In contrast, the uncoated NPs were taken up in large amounts, whereas the presence of

Silica micro/nanospheres for theranostics: from bimodal MRI and fluorescent imaging probes to cancer therapy

• Shanka Walia and
• Amitabha Acharya

Beilstein J. Nanotechnol. 2015, 6, 546–558, doi:10.3762/bjnano.6.57

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

• containing SCIONs. To exclude background fluorescence of extracellular adherent SCIONs, single cells were marked by the help of fluorescently labeled transferrin (Transferrin From Human Serum, Alexa Fluor® 488 Conjugate, Invitrogen, Cat.No. T-13342). After that the mean intensity of the SCION fluorescence

• concentration 50 µg/mL, error bars: SEM, n = 3). Fluorescence image of Hela cells which were incubated with SCIONs (iron concentration 5 µg/mL, incubation time 4 h), blue = DAPI (nuclei), green = Transferrin Alexa Fluor® 488 conjugate (cytosol), red = Alexa Fluor® 555 (SCIONs); (a) Control cells without siRNA

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

• of nanomedicine. The covalent grafting of BNNTs with human transferrin, linked through a carbamide bond, was reported [67]. The transferrin–BNNTs were tested on primary human umbilical vein endothelial cells (HUVECs) to investigate their cellular uptake. It was concluded that the functionalization of

The fate of a designed protein corona on nanoparticles in vitro and in vivo

• Denise Bargheer,
• Julius Nielsen,
• Gabriella Gébel,
• Markus Heine,
• Sunhild C. Salmen,
• Roland Stauber,
• Horst Weller,
• Joerg Heeren and
• Peter Nielsen

Beilstein J. Nanotechnol. 2015, 6, 36–46, doi:10.3762/bjnano.6.5

• surface was modified by PEGylation with mono- or bifunctional poly(ethylene oxide)amines (PEG). Using 125I-labeled test proteins (transferrin, albumin), the binding and exchange of corona proteins was studied first in vitro. Incubation with 125I-transferrin showed that with increasing grade of PEGylation

• the binding was substantially diminished without a difference between simply adsorbed and covalently bound protein. However, after incubation with excess albumin and subsequently whole plasma, transferrin from the preformed transferrin corona was more and more lost from SPIOs in the case of adsorbed

• proteins. If non-labeled transferrin was used as preformed corona and excess 125I-labeled albumin was added to the reaction mixtures with different SPIOs, a substantial amount of label was bound to the particles with initially adsorbed transferrin but little or even zero with covalently bound transferrin

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

• Human Caco-2 BBe1 cells (ATCC, via LGC Standards, Wesel, Germany) of passage 68–73 were maintained in DMEM, high glucose with sodium pyruvate, supplemented with 4 mM L-glutamine, 10% fetal bovine serum (FBS), 10 µg/mL human transferrin and 1% penicillin–streptomycin solution. The cells were cultured at

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

• agglomeration behavior [5]. The proteins chosen were albumin, transferrin and apolipoprotein A-1, which exist both in blood serum and in the lung epithelial lining fluid. Protein concentrations before and after NP incubation were determined by a depletion method using the Bio-Rad protein assay. In all cases, a

• < 0.05 (*), p < 0.01 (**), p < 0.001 (***). Mass and surface area related to binding indices BI of the NP to the three different proteins, albumin, transferrin and apolipoprotein A-1. Reproduced with permission from [5]. Copyright 2011 Informa Plc. Diameter refers to the geometrical diameter as observed

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

• and is, like most pinocytotic pathways, a form of receptor-mediated endocytosis. This abundant pathway is essential for the uptake of many molecules such as low-density lipoprotein and transferrin [24][25]. When clathrin-mediated endocytosis is initiated, the so-called “coated pits” come into play

• ]. Monodansylcadaverine (MDC), a competitive inhibitor, blocks the enzyme transglutaminase 2, which is necessary for receptor crosslinking in the region of clathrin-coated pits [31][39][40]. Furthermore, chlorpromazine and MDC are specific in inhibiting the uptake of the serum protein transferrin [41]. Consequently

• , fluorescently labelled transferrin can be used to investigate clathrin-mediated endocytosis [32][41][42]. Caveolae and lipid raft internalizations are known to be inhibited by nystatin, filipin and methyl-β-cyclodextrin (mβcd) through depletion of the cholesterol from the cell membrane by forming inclusion

Characterization of protein adsorption onto FePt nanoparticles using dual-focus fluorescence correlation spectroscopy

• Pauline Maffre,
• Karin Nienhaus,
• Faheem Amin,
• Wolfgang J. Parak and
• G. Ulrich Nienhaus

Beilstein J. Nanotechnol. 2011, 2, 374–383, doi:10.3762/bjnano.2.43

• thickness on these NPs, and time-resolved fluorescence quenching experiments revealed a typical protein residence time of ~100 s [11]. For transferrin [8], an important blood plasma protein involved in iron transport and delivery, we observed formation of a 7 nm thick protein corona. The FCS method is based

• . Figure 2 shows the dependence of RH on the logarithm of the protein concentration, as obtained from the 2fFCS correlation data. For all three proteins, RH increases in a stepwise fashion with protein concentration, as we previously reported for HSA and transferrin [8][11], which indicates a limited

• that the thickness of the protein corona, ΔRH, is a characteristic of the particular protein species adsorbed. In our previous studies with HSA [11] and transferrin [8], we noticed that the thickness of the protein corona was correlated with the molecular dimensions of the proteins as obtained from the