Nanotoxicology: How do nanotubes suppress T cells?

Alison Elder

Published online: 14 June 2009 | doi:10.1038/nnano.2009.167

Mice inhaling low levels of multiwalled carbon nanotubes show suppressed immune function. New studies suggest that this suppression originates from signals in the lungs.

Full Text - NanotoxicologyHow do nanotubes suppress T cells? | PDF (197 KB) - NanotoxicologyHow do nanotubes suppress T cells?

Correlated electron systems: Better than average

Douglas Natelson

Published online: 24 May 2009 | doi:10.1038/nnano.2009.124

Experiments on single-crystal nanobeams have revealed several new aspects of a phenomenon that has puzzled physicists for decades — the metal–insulator transition in vanadium dioxide.

Full Text - Correlated electron systemsBetter than average | PDF (94 KB) - Correlated electron systemsBetter than average

Evaluation of nanoparticle immunotoxicity

Marina A. Dobrovolskaia, Dori R. Germolec & James L. Weaver

Published online: 28 June 2009 | doi:10.1038/nnano.2009.175

Abstract - | Full Text - Evaluation of nanoparticle immunotoxicity | PDF (162 KB) - Evaluation of nanoparticle immunotoxicity | Supplementary information

Determination of protein structural flexibility by microsecond force spectroscopy

Mingdong Dong, Sudhir Husale & Ozgur Sahin

Published online: 28 June 2009 | doi:10.1038/nnano.2009.156

The flexibility of biomolecules at the microsecond timescale can be monitored under physiologically relevant conditions and with high spatial resolution using a technique based on atomic force microscopy.

Abstract - | Full Text - Determination of protein structural flexibility by microsecond force spectroscopy | PDF (1,367 KB) - Determination of protein structural flexibility by microsecond force spectroscopy | Supplementary information

Transfer of gold nanoparticles from the water column to the estuarine food web

John L. Ferry, Preston Craig, Cole Hexel, Patrick Sisco, Rebecca Frey, Paul L. Pennington, Michael H. Fulton, I. Geoff Scott, Alan W. Decho, Shosaku Kashiwada, Catherine J. Murphy & Timothy J. Shaw

Published online: 21 June 2009 | doi:10.1038/nnano.2009.157

Gold nanorods added to a laboratory-constructed estuarine mesocosm can accumulate in sediments, biofilms and various organisms such as fish, snails and shrimp. Most of the nanorods ended up in biofilms and clams, indicating that these nanoparticles could readily pass from the water column into the marine food web.

Abstract - | Full Text - Transfer of gold nanoparticles from the water column to the estuarine food web | PDF (459 KB) - Transfer of gold nanoparticles from the water column to the estuarine food web | Supplementary information

Nanoscale shape-memory alloys for ultrahigh mechanical damping

Jose San Juan, Maria L. Nó & Christopher A. Schuh

Published online: 07 June 2009 | doi:10.1038/nnano.2009.142

Shape-memory alloys undergo reversible transformations between two distinct phases. Now researchers have shown that nanoscale pillars made of shape-memory alloys have a figure of merit for mechanical damping — substantially higher than the figures previously reported for bulk materials — making these nanopillars attractive for use in future microscale and smaller devices.

Abstract - | Full Text - Nanoscale shape-memory alloys for ultrahigh mechanical damping | PDF (3,925 KB) - Nanoscale shape-memory alloys for ultrahigh mechanical damping | Supplementary information

Droplet networks with incorporated protein diodes show collective properties

Giovanni Maglia, Andrew J. Heron, William L. Hwang, Matthew A. Holden, Ellina Mikhailova, Qiuhong Li, Stephen Cheley & Hagan Bayley

Published online: 07 June 2009 | doi:10.1038/nnano.2009.121

Aqueous droplets connected by single lipid bilayers have been used to examine the properties of protein channels and pores, and networks of droplets can form microscale batteries and detect light. Now, by inserting an engineered pore with diode-like properties into the interface bilayers, droplet networks that mimic simple electronic devices have been produced.

Abstract - | Full Text - Droplet networks with incorporated protein diodes show collective properties | PDF (1,150 KB) - Droplet networks with incorporated protein diodes show collective properties | Supplementary information

Observation of the triplet exciton in EuS-coated single-walled nanotubes

Aditya D. Mohite, Tiffany S. Santos, Jagadeesh S. Moodera & Bruce W. Alphenaar

Published online: 07 June 2009 | doi:10.1038/nnano.2009.122

Excitons are created when a carbon nanotube absorbs photons. However, the triplet exciton is usually optically inactive, preventing its direct observation, lowering photocurrent efficiency and making optical injection of spin-polarized carriers impossible. Optical excitation of the triplet exciton has now been achieved.

Abstract - | Full Text - Observation of the triplet exciton in EuS-coated single-walled nanotubes | PDF (372 KB) - Observation of the triplet exciton in EuS-coated single-walled nanotubes | Supplementary information

New aspects of the metal–insulator transition in single-domain vanadium dioxide nanobeams

Jiang Wei, Zenghui Wang, Wei Chen & David H. Cobden

Published online: 24 May 2009 | doi:10.1038/nnano.2009.141

Many strongly correlated electron systems have a domain structure that obscures the fundamental properties of the homogeneous material. Experiments on single-domain nanobeams made of vanadium dioxide have revealed several new aspects of the metal–insulator transition in this material.

Abstract - | Full Text - New aspects of the metal–insulator transition in single-domain vanadium dioxide nanobeams | PDF (748 KB) - New aspects of the metal–insulator transition in single-domain vanadium dioxide nanobeams

See also: News and Views by Natelson

Multifunctional nanoarchitectures from DNA-based ABC monomers

Jong B. Lee, Young H. Roh, Soong Ho Um, Hisakage Funabashi, Wenlong Cheng, Judy J. Cha, Pichamon Kiatwuthinon, David A. Muller & Dan Luo

Published online: 03 May 2009 | doi:10.1038/nnano.2009.93

Multifunctional nanostructures have been created from DNA-based anisotropic, branched and crosslinkable building blocks — ABC monomers. Using these monomers, a target-driven polymerization process is demonstrated where polymers are generated only in the presence of a specific DNA molecule, leading to highly sensitive pathogen detection. The nanoarchitectures can also be used to deliver drugs to cells.

Abstract - | Full Text - Multifunctional nanoarchitectures from DNA-based ABC monomers | PDF (2,326 KB) - Multifunctional nanoarchitectures from DNA-based ABC monomers | Supplementary information

Self-assembled cationic peptide nanoparticles as an efficient antimicrobial agent

Lihong Liu, Kaijin Xu, Huaying Wang, P. K. Jeremy Tan, Weimin Fan, Subbu S. Venkatraman, Lanjuan Li & Yi-Yan Yang

Published online: 28 June 2009 | doi:10.1038/nnano.2009.153

A class of core–shell nanoparticles self-assembled from amphiphilic peptides can kill a range of bacteria, yeast and fungus. They are more potent than their unassembled peptide counterparts and can suppress bacterial growth in the brains of rabbits infected with meningitis. These particles, which carry a high number of positive charges, are promising antimicrobial agents.

Abstract - | Full Text - Self-assembled cationic peptide nanoparticles as an efficient antimicrobial agent | PDF (1,145 KB) - Self-assembled cationic peptide nanoparticles as an efficient antimicrobial agent | Supplementary information

Towards single-molecule nanomechanical mass spectrometry

A. K. Naik, M. S. Hanay, W. K. Hiebert, X. L. Feng & M. L. Roukes

Published online: 21 June 2009 | doi:10.1038/nnano.2009.152

Mass detection of single biological molecules in real time by a nanoelectromechanical system (NEMS) is demonstrated for the first time, and this is used to perform first generation NEMS-based mass spectrometry. Precipitous frequency shifts, proportional to the mass of the molecules, are recorded in real time by the NEMS mass spectrometry system as protein molecules and nanoparticles adsorb, one-by-one, onto an ultrahigh frequency NEMS resonator.

Abstract - | Full Text - Towards single-molecule nanomechanical mass spectrometry | PDF (657 KB) - Towards single-molecule nanomechanical mass spectrometry | Supplementary information

Phase-locking of magnetic vortices mediated by antivortices

A. Ruotolo, V. Cros, B. Georges, A. Dussaux, J. Grollier, C. Deranlot, R. Guillemet, K. Bouzehouane, S. Fusil & A. Fert

Published online: 21 June 2009 | doi:10.1038/nnano.2009.143

A magnetic vortex can be made to gyrate by a d.c. spin-polarized current. Researchers have now demonstrated the synchronization of four magnetic vortices through their interaction with antivortices. This work could lead to improved nanoscale microwave oscillators and a new way to study the behaviour of interacting solitons.

Abstract - | Full Text - Phase-locking of magnetic vortices mediated by antivortices | PDF (698 KB) - Phase-locking of magnetic vortices mediated by antivortices | Supplementary information

Mechanisms for how inhaled multiwalled carbon nanotubes suppress systemic immune function in mice

L. A. Mitchell, F. T. Lauer, S. W. Burchiel & J. D. McDonald

Published online: 14 June 2009 | doi:10.1038/nnano.2009.151

It has been shown that inhaling multiwalled carbon nanotubes does not lead to significant lung inflammation, but can suppress the immune function of mice. Now it is demonstrated that signals in the lung can activate signals in the spleen to inhibit the immune function of mice inhaling low levels of nanotubes.

Abstract - | Full Text - Mechanisms for how inhaled multiwalled carbon nanotubes suppress systemic immune function in mice | PDF (619 KB) - Mechanisms for how inhaled multiwalled carbon nanotubes suppress systemic immune function in mice | Supplementary information

See also: News and Views by Elder