Chemoselective silicification of synthetic peptides and polyamines

• Maryna Abacilar,
• Fabian Daus and
• Armin Geyer

Beilstein J. Nanotechnol. 2015, 6, 103–110, doi:10.3762/bjnano.6.10

• components at the surface of the forming silica beads. Poulsen et al. investigated the mutual influence of peptides and LCPAs. Here we investigate the simplest scenario of chemoselective precipitation, which is the differentiation between two dissolved components, a cationic peptide and an oligoamine, that

• precipitate silica (Figure 2). Three amines with increasing number of nitrogen atoms, a basic peptide, and a toxin [14] that is not involved in biomineralization but stands exemplary for other amines capable of silica precipitation. Synthetic methods Figure 3 shows the synthetic strategies used to access the

• amine remains reactive for peptide coupling. The HBTU/HOBt-mediated condensation of a Fmoc-acylated amino acid and cleavage of the temporary protecting group Fmoc with piperidine was repeated in 15 cycles to obtain CTC-bound precursor of peptide 5 which was finally Boc-deprotected by TFA and

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

• interaction with the surface of the BNNTs. This study provides a deeper understanding into the nature of the interactions of amino acids (and perhaps similar molecules) with surface of the BNNTs [68]. The interaction of a peptide, HWSAWWIRSNQS, with BNNTs was studied using AFM [69]. It was found that the

• peptide–BNNT structure had an excellent dispersibility in water since the BNNTs were covered by this peptide. The study revealed that the presence of Trp (W), which has a benzene ring in the peptide sequence, exhibited a strong π–π interaction with the BNNT surfaces [69]. Dendrimers prepared from

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

• acids representative for an alimentary peptide source, we noticed that this seemed to have no substantial effect on the adherence of NPs to the cells, only with the 20 nm NPs slightly higher fluorescence intensities were measured (Figure 2A). Individual peptides and amino acids of this extract do

Localized surface plasmon resonances in nanostructures to enhance nonlinear vibrational spectroscopies: towards an astonishing molecular sensitivity

• Dan Lis and
• Francesca Cecchet

Beilstein J. Nanotechnol. 2014, 5, 2275–2292, doi:10.3762/bjnano.5.237

• molecule detection. Furthermore, this weak molecular contribution was still higher than the non-resonant contributions of water and silver particles. The authors confirmed the high sensitivity of the system with the peptide angiotensin I, as testified by the 40 times higher signal than that of SERS, while

Biopolymer colloids for controlling and templating inorganic synthesis

• Laura C. Preiss,
• Katharina Landfester and
• Rafael Muñoz-Espí

Beilstein J. Nanotechnol. 2014, 5, 2129–2138, doi:10.3762/bjnano.5.222

• used for templating. The toroidal structures formed by DNA condensates were used as soft templates for the formation of silver [64][65] and gold [66] nanoparticles by reduction of the metal salts (Figure 6). Rings resulting from the assembly of a bolaamphiphilic peptide molecule were reported as

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

• grown on smooth and electrically conducting indium tin oxide substrates (ito) nor on electrically-insulating RADA16 peptide thin-films (b), characterised by a similar nanoscale roughness s CNTs (c). The culture substrates do not alter the electrical passive properties of neuronal membranes (d

Real-time monitoring of calcium carbonate and cationic peptide deposition on carboxylate-SAM using a microfluidic SAW biosensor

• Anna Pohl and
• Ingrid M. Weiss

Beilstein J. Nanotechnol. 2014, 5, 1823–1835, doi:10.3762/bjnano.5.193

• below the solubility equilibrium. The peptide ES9, equal to the mollusc chitin synthase epitope, is less sensitive to changes in pH than its counterpart AS8 with a penta-lysine core, which lacks the flanking acidic residues. This study demonstrates the extraordinary potential of microfluidic surface

• acoustic wave biosensors to significantly expand our experimental capabilities for studying the principles underlying biomineralization in vitro. Keywords: biomineralization; calcium carbonate; love-type surface acoustic wave; poly-cationic peptide; Introduction Biomineralization is a natural process of

• (sequence, N→C: EEKKKKKES) and AS8 (sequence, N→C: AKKKKKAS) [46]. The ES9 peptide is derived from E22, one of four major extracellular loops of an enzyme involved in biomineralization [20][47]. Previous experiments suggest that self-assembly of E22 is fine-tuned in accordance with pH changes that may occur

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

• as those provided by the TAT peptide or surface functionalization, interact initially with the negatively charged heparan sulfate proteoglycan groups on the exterior of the cells. This allows them to then be present on the plasma cell membrane as endocytosis starts. Thus, while details may be very

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

• observation was not as predicted by the switchblade model and is more consistent with the deadbolt model. Goennenwein et al. reconstituted integrin αIIbβ3 into supported lipid bilayers to measure their adhesion force against RGD-peptide carrying giant vesicles. With this setup a simple and powerful tool was

Molecular biology approaches in bioadhesion research

• Marcelo Rodrigues,
• Birgit Lengerer,
• Thomas Ostermann and
• Peter Ladurner

Beilstein J. Nanotechnol. 2014, 5, 983–993, doi:10.3762/bjnano.5.112

• start, because it uses Ruby’s built in webserver Webrick (http://www.ruby-doc.org/stdlib-2.0/libdoc/webrick/rdoc/WEBrick.html). Finally, any query sequence such as known adhesion-related transcripts of other organisms, mass spectrometry peptide sequences or candidate transcripts originated from a

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

• delivery system for bone metastatic prostate cancer was developed, characterized, and evaluated in vitro. NDs were conjugated with the Asp–Gly–Glu–Ala (DGEA) peptide to target α2β1 integrins over-expressed in prostate cancers during metastasis. To facilitate drug delivery, DOX was adsorbed to the surface

• from 2.5% to 12% cell death and 11% to 34% cell death, respectively. These studies confirmed that the delivery and efficacy of DOX were enhanced by ND-DGEA conjugates. Thus, the targeted ND-DGEA+DOX system provides a novel approach for decreasing toxicity and drug doses. Keywords: DGEA peptide

• prostate cancers, targeted drug delivery with a ligand that interacts with these integrins should allow for increased accumulation of drug systems in cancer cells versus normal cells or tissues. Asp–Gly–Glu–Ala (DGEA) peptide has been identified as a binding peptide for the α2β1 integrins; it corresponds

Biocalcite, a multifunctional inorganic polymer: Building block for calcareous sponge spicules and bioseed for the synthesis of calcium phosphate-based bone

• Xiaohong Wang,
• Heinz C. Schröder and
• Werner E. G. Müller

Beilstein J. Nanotechnol. 2014, 5, 610–621, doi:10.3762/bjnano.5.72

• reaction (hydration of CO2) are present in the CA-alpha (vertebrate-like) group stretch of the S. raphanus protein. The Zn ions are bound to the enzyme through the three His residues in the catalytic center of the enzyme [41]. The presence of a signal peptide cleavage site in the sponge CA indicates that

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

• in 50 mM MES/HEPES buffer (75:25 v/v) pH 6.0, 50 mM EDC and 30 mM NTEE was incubated at 30 °C for 45 min. Subsequently, the reaction was terminated with the addition of 1 mL of 10% TCA, and the precipitated Gd-peptide complex was collected by centrifugation, washed extensively with chilled acetone

Oriented attachment explains cobalt ferrite nanoparticle growth in bioinspired syntheses

• Annalena Wolff,
• Walid Hetaba,
• Marco Wißbrock,
• Stefan Löffler,
• Nadine Mill,
• Katrin Eckstädt,
• Axel Dreyer,
• Inga Ennen,
• Norbert Sewald,
• Peter Schattschneider and
• Andreas Hütten

Beilstein J. Nanotechnol. 2014, 5, 210–218, doi:10.3762/bjnano.5.23

• . The change in surface energy can be explained if c25-mms6 interacts with the crystallites in such a way that growth in which the (111) final crystal face forms is favoured. Growth modification by peptide adsorption has previously been reported [9][21][22]. The polypeptide-stabilized crystallites

• ]. However, this mechanism has not been verified yet and another interaction mechanism based on face-specific peptide adsorption is also possible and should be investigated. The fate of c25-mms6 during the fusion of the pbb cannot be deduced from the results. Whether the polypeptide is released from the pbb

Controlled synthesis and tunable properties of ultrathin silica nanotubes through spontaneous polycondensation on polyamine fibrils

• Jian-Jun Yuan,
• Pei-Xin Zhu,
• Daisuke Noda and
• Ren-Hua Jin

Beilstein J. Nanotechnol. 2013, 4, 793–804, doi:10.3762/bjnano.4.90

• ][23][24][25][26][27][28][29] or amine-modified polysaccharides [30] have been used as template for the formation of silica nanotubes. For example, Yuwono et al. [23] reported the use of peptide-amphiphile nanofiber templates in order to direct the synthesis of hollow silica nanotubes with outer

Molecular dynamics simulations of mechanical failure in polymorphic arrangements of amyloid fibrils containing structural defects

• Hlengisizwe Ndlovu,
• Alison E. Ashcroft,
• Sheena E. Radford and
• Sarah A. Harris

Beilstein J. Nanotechnol. 2013, 4, 429–440, doi:10.3762/bjnano.4.50

• by protein or peptide self-assembly depends on the environmental growth conditions such as pH, temperature, salt concentration and mechanical agitation [10]. Since amyloid polymorphs have been observed with drastically different morphologies [11] and chemical properties [12], it is important to

• ], investigated fibril failure under tensile loading [21], revealed that geometrical confinement of β-sheets in spider silk leads to mechanical enhancement [22], and highlighted the role played by the peptide sequence on the mechanical resistance of amylin-derived fibrils [23]. In this work, three polymorphs of

• steric arrangements found in the three different polymorph symmetry classes influence fibril mechanical behaviour. The fibrils are probed from different directions, using distinct pulling geometries that we developed previously to study the role of the peptide sequence in modulating amyloid mechanical

Controlled deposition and combing of DNA across lithographically defined patterns on silicon

• Zeinab Esmail Nazari and
• Leonid Gurevich

Beilstein J. Nanotechnol. 2013, 4, 72–76, doi:10.3762/bjnano.4.8

• DNA–peptide conjugates. We suggest this method as a simple yet reliable technique for depositing and aligning DNA and DNA derivatives across nanofabricated patterns. Keywords: AFM; DNA molecular combing; DNA–peptide complexes; molecular electronics; surface modification; Introduction DNA is the

• stretching of various DNA–peptide conjugates. These nanomaterials have been recently prepared by our team and are composed of a dsDNA core and peripheral coating layer of self-assembled cationic peptides [21][22]. Results and Discussion As was mentioned above, DNA molecules acquire a relatively compact

• –peptide conjugates, while the original recipe was proven to be ineffective for combing these materials [11]. Figure 3 represents the topography of combed dsDNA conjugated with various peptides. Combing across nanoelectrodes was also possible for DNA–peptide conjugates (Figure 3e). The gas-phase deposition

Magnetic-Fe/Fe₃O₄-nanoparticle-bound SN38 as carboxylesterase-cleavable prodrug for the delivery to tumors within monocytes/macrophages

• Hongwang Wang,
• Tej B. Shrestha,
• Matthew T. Basel,
• Raj K. Dani,
• Gwi-Moon Seo,
• Sivasai Balivada,
• Marla M. Pyle,
• Heidy Prock,
• Olga B. Koper,
• Prem S. Thapa,
• David Moore,
• Ping Li,
• Viktor Chikan,
• Deryl L. Troyer and
• Stefan H. Bossmann

Beilstein J. Nanotechnol. 2012, 3, 444–455, doi:10.3762/bjnano.3.51

• [17][18][19]. SN38 conjugated to a cationic peptide (Vectocell) by an esterase cleavable linker has been reported. The conjugate (DTS-108) is highly soluble in water and liberated significantly higher levels of free SN38 than CPT-11 did in a dog model [20]. An alternate strategy is to use delivery

Distribution of functional groups in periodic mesoporous organosilica materials studied by small-angle neutron scattering with in situ adsorption of nitrogen

• Monir Sharifi,
• Dirk Wallacher and
• Michael Wark

Beilstein J. Nanotechnol. 2012, 3, 428–437, doi:10.3762/bjnano.3.49

• conductivities compared to grafted samples [25]. To the best of our knowledge there is only one report in the literature, by Mascotto et al., in which peptide-functionalized benzoic acid PMO materials were investigated by SAXS/SANS with in situ gas adsorption. The authors observed a complete contrast matching

Self-organizing bioinspired oligothiophene–oligopeptide hybrids

• Alexey K. Shaytan,
• Eva-Kathrin Schillinger,
• Elena Mena-Osteritz,
• Sylvia Schmid,
• Pavel G. Khalatur,
• Peter Bäuerle and
• Alexei R. Khokhlov

Beilstein J. Nanotechnol. 2011, 2, 525–544, doi:10.3762/bjnano.2.57

• self-assembly and stimuli-responsive properties, provided by the peptide moieties combined with the semiconducting properties of the thiophene blocks, can result in novel opportunities for the design of advanced smart materials. These bio-inspired molecular hybrids are experimentally shown to form

• applications as building blocks in nano- and biotechnology. Understanding the molecular details of peptide self-assembly into fibrillar aggregates has been a challenge owing to the large size, low solubility, and the noncrystalline and heterogeneous nature of the fibrils. During the last decade, considerable

• progress in our understanding of the principles of fibril formation has been made owing to numerous experimental and theoretical studies and, importantly, the resolution of peptide arrangements at the atomistic level by means of X-ray crystallography and solid-state NMR [4][5][6]. The outstanding ability

Magnetic nanoparticles for biomedical NMR-based diagnostics

• Huilin Shao,
• Tae-Jong Yoon,
• Monty Liong,
• Ralph Weissleder and
• Hakho Lee

Beilstein J. Nanotechnol. 2010, 1, 142–154, doi:10.3762/bjnano.1.17

• ], endonucleases and methylases [39]. In these assays, the enzyme activity disassembles pre-formed clusters of MNPs; this disintegration translates the enzymatic activity into a detectable T2 signal. In the first demonstration of this strategy, MNP aggregates were formed with the peptide sequence biotin-GDEVDGC

• . This sequence served as a linker, binding both an avidin-conjugated CLIO population (via the biotin/avidin interaction) as well as a second CLIO population (via the thiol provided by the terminal cysteine on the peptide) [13]. The subsequent addition of caspase-3 disassembled the aggregates by cleaving

• caspase-3. MNPs were clustered with a peptide linker containing the sequence DEVD and were rapidly dissociated upon the activity of caspase-3. This dissociation was not observed when a specific caspase-3 inhibitor was added. The enzyme-dependent disassembly of the MNP clusters resulted in an increase in