Free-standing kinked nanowire transistor probes for targeted intracellular recording in three dimensions

Nature Nanotechnology 9, 142 (2014). doi:10.1038/nnano.2013.273

Authors: Quan Qing, Zhe Jiang, Lin Xu, Ruixuan Gao, Liqiang Mai & Charles M. Lieber

Quan Qing

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Engineering myosins for long-range transport on actin filaments

Nature Nanotechnology 9, 33 (2014). doi:10.1038/nnano.2013.229

Authors: Tony D. Schindler, Lu Chen, Paul Lebel, Muneaki Nakamura & Zev Bryant

Tony D. Schindler

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A synthetic DNA motor that transports nanoparticles along carbon nanotubes

Nature Nanotechnology 9, 39 (2014). doi:10.1038/nnano.2013.257

Authors: Tae-Gon Cha, Jing Pan, Haorong Chen, Janette Salgado, Xiang Li, Chengde Mao & Jong Hyun Choi

Tae-Gon Cha

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Transport and self-organization across different length scales powered by motor proteins and programmed by DNA

Nature Nanotechnology 9, 44 (2014). doi:10.1038/nnano.2013.230

Authors: Adam J. M. Wollman, Carlos Sanchez-Cano, Helen M. J. Carstairs, Robert A. Cross & Andrew J. Turberfield

Adam J. M. Wollman

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Molecular-sized fluorescent nanodiamonds

Nature Nanotechnology 9, 54 (2014). doi:10.1038/nnano.2013.255

Authors: Igor I. Vlasov, Andrey A. Shiryaev, Torsten Rendler, Steffen Steinert, Sang-Yun Lee, Denis Antonov, Márton Vörös, Fedor Jelezko, Anatolii V. Fisenko, Lubov F. Semjonova, Johannes Biskupek, Ute Kaiser, Oleg I. Lebedev, Ilmo Sildos, Philip. R. Hemmer, Vitaly I. Konov, Adam Gali & Jörg Wrachtrup

Igor I. Vlasov

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Spin Hall effect clocking of nanomagnetic logic without a magnetic field

Nature Nanotechnology 9, 59 (2014). doi:10.1038/nnano.2013.241

Authors: Debanjan Bhowmik, Long You & Sayeef Salahuddin

Debanjan Bhowmik

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Control of single-spin magnetic anisotropy by exchange coupling

Nature Nanotechnology 9, 64 (2014). doi:10.1038/nnano.2013.264

Authors: Jenny C. Oberg, M. Reyes Calvo, Fernando Delgado, María Moro-Lagares, David Serrate, David Jacob, Joaquín Fernández-Rossier & Cyrus F. Hirjibehedin

Jenny C. Oberg

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Efficient solar water-splitting using a nanocrystalline CoO photocatalyst

Nature Nanotechnology 9, 69 (2014). doi:10.1038/nnano.2013.272

Authors: Longb Liao, Qiuhui Zhang, Zhihua Su, Zhongzheng Zhao, Yanan Wang, Yang Li, Xiaoxiang Lu, Dongguang Wei, Guoying Feng, Qingkai Yu, Xiaojun Cai, Jimin Zhao, Zhifeng Ren, Hui Fang, Francisco Robles-Hernandez, Steven Baldelli & Jiming Bao

Longb Liao

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Hierarchical assembly of metal nanoparticles, quantum dots and organic dyes using DNA origami scaffolds

Nature Nanotechnology 9, 74 (2014). doi:10.1038/nnano.2013.253

Authors: Robert Schreiber, Jaekwon Do, Eva-Maria Roller, Tao Zhang, Verena J. Schüller, Philipp C. Nickels, Jochen Feldmann & Tim Liedl

Robert Schreiber

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Spin-resolved Andreev levels and parity crossings in hybrid superconductor–semiconductor nanostructures

Nature Nanotechnology 9, 79 (2014). doi:10.1038/nnano.2013.267

Authors: Eduardo J. H. Lee, Xiaocheng Jiang, Manuel Houzet, Ramón Aguado, Charles M. Lieber & Silvano De Franceschi

Eduardo J. H. Lee

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Optimizing manufacturing and composition of a TLR4 nanosuspension: physicochemical stability and vaccine adjuvant activity

Background: Nanosuspensions are an important class of delivery system for vaccine adjuvants and drugs. Previously, we developed a nanosuspension consisting of the synthetic TLR4 ligand glucopyranosyl lipid adjuvant (GLA) and dipalmitoyl phosphatidylcholine (DPPC). This nanosuspension is a clinical vaccine adjuvant known as GLA-AF. We examined the effects of DPPC supplier, buffer composition, and manufacturing process on GLA-AF physicochemical and biological activity characteristics. Results: DPPC from different suppliers had minimal influence on physicochemical and biological effects. In general, buffered compositions resulted in less particle size stability compared to unbuffered GLA-AF. Microfluidization resulted in rapid particle size reduction after only a few passes, and 20,000 or 30,000 psi processing pressures were more effective at reducing particle size and recovering the active component than 10,000 psi. Sonicated and microfluidized batches maintained good particle size and chemical stability over 6 months, without significantly altering in vitro or in vivo bioactivity of GLA-AF when combined with a recombinant malaria vaccine antigen. Conclusions: Microfluidization, compared to water bath sonication, may be an effective manufacturing process to improve the scalability and reproducibility of GLA-AF as it advances further in the clinical development pathway. Various sources of DPPC are suitable to manufacture GLA-AF, but buffered compositions of GLA-AF do not appear to offer stability advantages over the unbuffered composition.

HW Fung

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Synthesis of well-dispersed silver nanorods of different aspect ratios and their antimicrobial properties against gram positive and negative bacterial strains

In the present contribution, we describe the synthesis of highly dispersed silver nanorods (NRs) of different aspect ratios using a chemical route. The shape and size of the synthesized NRs were characterized by Transmission Electron Microscopy (TEM) and UV-visible spectroscopy. Longitudinal and transverse absorptions bands confirm the rod type structure. The experimentally recorded UV-visible spectra of NRs solutions were fitted by using an expression of the extinction coefficient for rod like nano structures under the dipole approximation. Simulated and experimentally observed UV-visible spectra were compared to determine the aspect ratios (R) of NRs. The average values of R for NR1, NR2 and NR3 solutions are estimated to be 3.0 +/- 0.1, 1.8 +/- 0.1 and 1.2 +/- 0.1, respectively. These values are in good agreement with those obtained by TEM micrographs. The silver NRs of known aspect ratios are used to study antimicrobial activities against B.subtilis (gram positive) and E.coli (gram negative) microbes. We observed that the NRs of intermediate aspect ratio (R = 1.8) have greater antimicrobial effect against both, B.subtilis (gram positive) and E.coli (gram negative). The NRs of aspect ratio, R = 3.0 has better antimicrobial activities against gram positive than on the gram negative.

Animesh Ojha

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Tuning the oriented deposition of gold nanorods on patterned substrates

The controlled patterning of anisotropic gold nanoparticles is of crucial importance for many applications related to their optical properties. In this paper, we report that gold nanorods prepared by a seed-mediated synthesis protocol (without any further functionalization) can be selectively deposited on hydrophilic parts of hydrophobic–hydrophilic contrast patterned substrates. We have seen that, when nanorods with lengths much smaller than the width of the hydrophilic stripe are used, they disperse on these stripes with random orientation and tunable uniform particle separation. However, for nanorods having lengths comparable to the width of the hydrophilic stripes, confinement-induced alignment occurs. We observe that different interactions governing the assembly forces can be modulated by controlling the concentration of assembling nanorods and the width of the hydrophilic stripes, leading to markedly different degrees of alignment. Our strategy can be replicated for other a...



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Triggering cell death by nanographene oxide mediated hyperthermia

Graphene oxide (GO) has been proposed as an hyperthermia agent for anticancer therapies due to its near-infrared (NIR) optical absorption ability which, with its small two-dimensional size, could have a unique performance when compared to that of any other nanoparticle. Nevertheless, attention should be given to the hyperthermia route and the kind of GO–cell interactions induced in the process. The hyperthermia laser irradiation parameters, such as exposure time and laser power, were investigated to control the temperature rise and consequent damage in the GOs containing cell culture medium. The type of cell damage produced was evaluated as a function of these parameters. The results showed that cell culture temperature (after irradiating cells with internalized GO) increases preferentially with laser power rather than with exposure time. Moreover, when laser power is increased, necrosis is the preferential cell death leading to an increase of cytokine release to the medium.

M Vila, M C Matesanz, G Gonçalves, M J Feito, J Linares, P A A P Marques, M T Portolés and M Vallet-Regi

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Multi-frequency near-field scanning optical microscopy

We demonstrate a new multi-frequency approach for mapping near-field optically induced forces with subwavelength spatial resolution. The concept relies on oscillating a scanning probe at two different frequencies. Oscillations at one frequency are driven electrically to provide positional feedback regulation. Modulations at another frequency are induced optically and are used to measure the mechanical action of the optical field on the probe. Because the measurement is based on locally detecting the force of the electromagnetic radiation acting on the probe, the new method does not require a photodetector to map the radiation distribution and, therefore, can provide true broadband detection of light with a single probe.

Dana C Kohlgraf-Owens, Léo Greusard, Sergey Sukhov, Yannick De Wilde and Aristide Dogariu

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Optical properties and sensing in plexcitonic nanocavities: from simple molecular linkers to molecular aggregate layers

We present a theoretical study of a metal–molecular aggregate hybrid system consisting of a strongly coupled dimer connected by molecules characterized by an excitonic transition. The plasmonic resonances of the metallic dimer interact with the molecular excitations giving rise to coupled plasmon–exciton states, so called plexcitons. We compare the differences in the optical response when the excitonic material is placed only as a linker in the plasmonic gap of the dimer and when the material is distributed as an aggregate layer covering the dimer entirely. We also explore the efficiency of plexcitons for localized surface plamon resonance (LSPR) sensing in both situations. The ordinary shift-based sensing is more efficient for dimers connected through molecular linkers, whereas intensity-based sensing is more effective when the molecular aggregate covers the entire nanostructure. These results can serve to design the chemistry of excitons around metallic nanoparticles.

Olalla Pérez-González, Nerea Zabala and Javier Aizpurua

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Antitumor activity of photodynamic therapy performed with nanospheres containing zinc-phthalocyanine

Background: The increasing incidence of cancer and the search for more effective therapies with minimal collateral effects have prompted studies to find alternative new treatments. Among these, photodynamic therapy (PDT) has been proposed as a very promising new modality in cancer treatment with the lowest rates of side effects, revealing itself to be particularly successful when the photosensitizer is associated with nanoscaled carriers. This study aimed to design and develop a new formulation based on albumin nanospheres containing zinc-phthalocyanine tetrasulfonate (ZnPcS4-AN) for use in the PDT protocol and to investigate its antitumor activity in Swiss albino mice using the Ehrlich solid tumor as an experimental model for breast cancer. Methods: Ehrlich tumor's volume, histopathology and morphometry were used to assess the efficacy of intratumoral injection of ZnPcS4-AN in containing tumor aggressiveness and promoting its regression, while the toxicity of possible treatments was assessed by animal weight, morphological analysis of the liver and kidneys, hemogram, and serum levels of total bilirubin, direct bilirubin, indirect bilirubin, aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma glutamyl transferase (GGT), alkaline phosphatase, creatinine and urea. In order to evaluate the efficacy of PDT, groups of animals treated with intratumoral injection of doxorubicin (Dox) were also investigated. Results: Intratumoral injection of ZnPcS4-AN was found to be efficient in mediating PDT to refrain tumor aggressiveness and to induce its regression. Although tumor volume reduction was not significant, PDT induced a remarkable increase in the necrosis area seen in the tumor's central region, as in other experimental groups, including tumor and Dox treated groups, but also in the tumor's peripheral region. Further, PDT showed minimal adverse effects. Indeed, the use of ZnPcS4-AN in mediating PDT revealed anti-neoplastic activity similar to that obtained while using intratumoral Dox therapy. Conclusions: PDT mediated by the new formulation ZnPcS4-AN enhanced the inhibition of tumor growth while producing practically no adverse effects and thus emerges as a very promising nanotechnology-based strategy for solid cancer treatment.

Flávia Portilho

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Mitigating prolonged QT interval in cancer nanodrug development for accelerated clinical translation

Background: Cardiac toxicity is the foremost reason for drug discontinuation from development to clinical evaluation and post market surveillance [Fung 35:293-317, 2001; Piccini 158:317-326 2009]. The Food and Drug Administration (FDA) has rejected many potential pharmaceutical agents due to QT prolongation effects. Since drug development and FDA approval takes an enormous amount of time, money and effort with high failure rates, there is an increased focus on rescuing drugs that cause QT prolongation. If these otherwise safe and potent drugs were formulated in a unique way so as to mitigate the QT prolongation associated with them, these potent drugs may get FDA approval for clinical use. Rescuing these compounds not only benefit the patients who need them but also require much less time and money thus leading to faster clinical translation. In this study, we chose curcumin as our drug of choice since it has been shown to posses anti-tumor properties against various cancers with limited toxicity. The major limitations with this pharmacologically active drug are (a) its ability to prolong QT by inhibiting the hERG channel and (b) its low bioavailability. In our previous studies, we found that lipids have protective actions against hERG channel inhibition and therefore QT prolongation. Results: Results of the manual patch clamp assay of HEK 293 cells clearly illustrated that our hybrid nanocurcumin formulation prevented the curcumin induced inhibition of hERG K+ channel at concentrations higher than the therapeutic concentrations of curcumin. Comparing the percent inhibition, the hybrid nanocurcumin limited inhibition to 24.8% at a high curcumin equivalent concentration of 18 muM. Liposomal curcumin could only decrease this inhibition upto 30% only at lower curcumin concentration of 6 muM but not at 18 muM concentration. Conclusions: Here we show a curcumin encapsulated lipopolymeric hybrid nanoparticle formulation which could protect against QT prolongation and also render increased bioavailability and stability thereby overcoming the limitations associated with curcumin.

Amalendu Ranjan

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One-to-one spatially matched experiment and atomistic simulations of nanometre-scale indentation

We have carried out nanoindentation studies of gold in which the indenter is atomically characterized by field-ion microscopy and the scale of deformation is sufficiently small to be directly compared with atomistic simulations. We find that many features of the experiment are correctly reproduced by molecular dynamics simulations, in some cases only when an atomically rough indenter rather than a smooth repulsive-potential indenter is used. Heterogeneous nucleation of dislocations is found to take place at surface defect sites. Using input from atomistic simulations, a model of indentation based on stochastic transitions between continuum elastic–plastic states is developed, which accurately predicts the size distributions of plastic ‘pop-in’ events and their dependence on tip geometry.

D J Oliver, W Paul, M El Ouali, T Hagedorn, Y Miyahara, Y Qi and P H Grütter

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Comparison of the magnetic, radiolabeling, hyperthermic and biodistribution properties of hybrid nanoparticles bearing CoFe 2 O 4 and Fe 3 O 4 metal cores

Metal oxide nanoparticles, hybridized with various polymeric chemicals, represent a novel and breakthrough application in drug delivery, hyperthermia treatment and imaging techniques. Radiolabeling of these nanoformulations can result in new and attractive dual-imaging agents as well as provide accurate in vivo information on their biodistribution profile. In this paper a comparison study has been made between two of the most promising hybrid core–shell nanosystems, bearing either magnetite (Fe 3 O 4 ) or cobalt ferrite (CoFe 2 O 4 ) cores, regarding their magnetic, radiolabeling, hyperthermic and biodistribution properties. While hyperthermic properties were found to be affected by the metal-core type, the radiolabeling ability and the in vivo fate of the nanoformulations seem to depend critically on the size and the shell composition.



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