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Fabrizio Gelain and co-workers have developed a biocompatible scaffold which is capable of encouraging the regeneration of neural precursor cells derived from neural stem cell in mice. The regeneration of nerve tissue after spinal injury is important but difficult to achieve. The groups reports a promising strategy for neural cell regeneration and they suggest that the approach may have wider applications in other areas of tissue engineering.

One of the stunning images of the mouse neurons they studied has been selected to feature in Chemistry World’s Chemistry through the lens feature.

Zeiss Apotome microscopy showing a highly organised network of beta-tubulin positive (green) murine neurons, GFAP (red) astrocytes and nuclei marked with DAPI (blue).

Read this exciting research paper in full today:

New bioactive motifs and their use in functionalized self-assembling peptides for NSC differentiation and neural tissue engineering
F. Gelain , D. Cigognini , A. Caprini , D. Silva , B. Colleoni , M. Donegá , S. Antonini , B. E. Cohen and A. Vescovi
DOI: 10.1039/C2NR30220A

Following on from their discovery of graphene “speakers”, scientists in China have done more detailed study of the amplitude and frequency of the sound at different distances and angles, and the temperature dependence of the sound frequency. The authors are optimistic about the applications of these devices in  multimedia and consumer electronics as well as biological and medical devices.

Read the full details of their exciting work:

Static behavior of graphene-based sound-emitting device
He Tian, Dan Xie, Yi Yang, Tian-Ling Ren, Yu-Feng Wang, Chang-Jian Zhou, Ping-Gang Peng, Li-Gang Wang and Li-Tian Liu
Nanoscale, 2012, DOI: 10.1039/C2NR30417A

You may also be interested in the authors’ original communication:

Single-layer graphene sound-emitting devices: experiments and modeling
He Tian, Dan Xie, Yi Yang, Tian-Ling Ren, Yu-Feng Wang, Chang-Jian Zhou, Ping-Gang Peng, Li-Gang Wang and Li-Tian Liu
Nanoscale, 2012, DOI: 10.1039/C2NR11572G

Scientists in China have developed a material that reduces the time required for a skin wound to heal.

A range of research has been conducted into the promising biomedical applications of chitosan, as it can clot blood effectively. Bingan Lu and his colleagues at Lanzhou University have developed a method to combine the benefits of chitosan with graphene, which has been shown to have antibacterial properties. 

Lu’s team mixed graphene with chitosan-polyvinyl alcohol (PVA) nanofibres using electrospinning (a process in which an electrical charge is applied to draw very fine fibres from the solution). The chitosan nanofibres combined with the graphene, forming thin membranes. 

The team applied the membranes to small skin wounds. Lu says that the membranes ‘covered the wounds like a band aid and, usually, one wound only needed one graphene-chitosan-PVA membrane’. They found that after 10 days, the wounds were significantly more healed than those without the membrane. 

A membrane formed from chitosan, which clots blood effectively, and graphene, which is antibacterial, speeds up wound healing

Chunhai Fan, an expert in graphene materials at the Chinese Academy of Sciences, says that the work ’shows a really interesting health application of graphene-based nanomaterials’ and adds that it ’clearly shows that graphene-based antibacterial materials facilitate wound healing’.

To test the membrane further, Lu’s team used cell cultures to show that graphene is only detrimental to bacterial cells, and animal cells are unaffected. They suggest that this may be due to graphene transferring electrons through cell membranes. Bacterial cells are prevented from replicating by this process, as the electrons can reach the bacterial DNA, destroying it. Animal DNA is protected from the electrons by a second membrane. The team intends to investigate graphene’s antibacterial properties to confirm the mechanism.

Graphene-based composite materials beneficial to wound healing
Bingan Lu, Ting Li, Haitao Zhao, Xiaodong Li, Caitian Gao, Shengxiang Zhang and Erqing Xie
DOI: 10.1039/C2NR11958G

Read the original article at Chemistry World

Dongsheng Guan and Ying Wang of Louisiana State University report a novel way to prepare multilayered TiO₂ nanotube arrays. In this study, TiO₂ nanotubes grow at a steady ready under stable pH and ion-diffusion conditions but, when the voltage is first reduced and then subsequently increased again, a second layer of nanotubes can be grown on top of the first.

The work casts light on the mechanism of TiO₂ nanotube growth and could see applications from batteries to solar cells.

Read this HOT Nanoscale article today:

Synthesis and growth mechanism of multilayer TiO₂ nanotube arrays
Dongsheng Guan and Ying Wang
Nanoscale, 2012, DOI: 10.1039/C2NR30315A

Self-disinfecting surfaces that reduce the activity of influenza A, hepatitis C and E. coli have been developed by scientists from the US.

The team from UCLA used zinc-copper-indium nanocrystals to make surfaces that allow oxygen species and other free radicals to form under visible light illumination. These active species reduce influenza A activity up to 94% and hepatitis C up to 85%.

Read this HOT communication today:

Visible light powered self-disinfecting coatings for influenza viruses
Ding Weng , Hangfei Qi , Ting-Ting Wu , Ming Yan , Ren Sun and Yunfeng Lu
Nanoscale, 2012, DOI: 10.1039/C2NR30388D

Scientists in Germany, the US and Finland have used graphene membranes as highly sensitive sensor devices for molecules on the nanoscale.

The molecules are adsorbed onto the graphene’s surface and then molecular dynamics are used to measure mass and other physical properties. The team showed that they can detect specific “fingerprints” left by the molecules on the graphene surface, which can be identified by IR or Raman spectroscopy. As the molecule moves on the surface, these dynamical movements can be detected by a graphene-based drum (a nanoscale “ear” that can hear “sounds” produced by other molecules).

The device could be used for nanoelectronics or to improve atomic force microscopy-based techniques.

Read the full details of this exciting work today:

Nanoscale ear drum: Graphene based nanoscale sensors
Stanislav Avdoshenko , Claudia Gomes Rochaa and Gionarelio Cuniberti
Nanoscale, 2012, DOI: 10.1039/C2NR30097D