This week Nature Nanotechnology journal reveals how scientists from the London Centre for Nanotechnology (LCN) at UCL are using a novel nanomechanical approach to investigate the workings of vancomycin, one of the few antibiotics that can be used to combat so-called ‘superbugs’, such as MRSA.

The researchers, led by Dr Rachel McKendry and Professor Gabriel Aeppli, developed ultra-sensitive probes capable of providing new insight into how antibiotics work, paving the way for the development of more effective new drugs.

“There has been an alarming growth in antibiotic-resistant hospital superbugs such as MRSA and vancomycin-resistant Enterococci (VRE),” said Dr McKendry. “This is a major global health problem and is driving the development of new technologies to investigate antibiotics and how they work.

“The cell wall of these bugs is weakened by the antibiotic, ultimately killing the bacteria,” she continued.

“Our research on cantilever sensors – tiny levers no wider than a human hair – suggests that the cell wall is disrupted by a combination of a local antibiotic and a polymer known as a mucopeptide binding together, and the spatial mechanical connectivity of these events.

“Investigating both these binding and mechanical influences on the cells’ structure could lead to the development of more powerful and effective antibiotics in future.”

During the study Dr McKendry, Joseph Ndieyira, Moyu Watari and co-workers used these cantilever arrays to examine the process that ordinarily takes place in the body when vancomycin binds itself to the surface of the bacteria.

They coated the cantilever array with polymers known as mucopeptides from bacterial cell walls and found that, as the antibiotic attaches itself it generates a surface stress on the bacteria, which can be detected by a tiny bending of the cantilever sensors.

The team suggests that this stress contributes to the disruption of the cell walls and the breakdown of the bacteria.

The interdisciplinary team went on to compare how vancomycin interacts with both non-resistant and resistant strains of bacteria. The ‘superbugs’ are resistant to antibiotics because of a simple mutation that deletes a single hydrogen bond from the structure of their cell walls.

This small change makes it approximately 1,000 times harder for the antibiotic to attach itself to the bug, leaving it much less able to disrupt the cells’ structure, and therefore therapeutically ineffective.

“This work at the LCN demonstrates the effectiveness of silicon-based cantilevers for drug screening applications,” says Professor Gabriel Aeppli, Director of the LCN.

“According to the Health Protection Agency, during 2007 there were around 7,000 cases of MRSA and more than a thousand cases of VRE in England alone. In recent decades the introduction of new antibiotics has slowed to a trickle but without effective new drugs the number of these fatal infections will increase.”

The research was funded by the EPSRC (Speculative Engineering Programme), the IRC in Nanotechnology (Cambridge, UCL and Bristol), the Royal Society and the BBSRC.

Futuristic electronics and energy technologies pave the way for 21st Century applications

Washington, DC – The future of how the world communicates, and how we power our lives, will likely come from the same source. According to the latest NanoFrontiers newsletter and Trips to the Nanofrontier podcast, nanotechnology will be central to developing advanced, “faster, better, cheaper” electronics and “green” energy technologies.

In the latest installment of the podcast series Trips to the Nanofrontier, journalist Karen Schmidt interviews Dr. Jim Heath about how computers, healthcare applications and other devices will use nanotechnology to exchange and obtain information more effectively.

But to power these new applications, as well as every other modern human activity, officials from industry and government are searching for new technologies that will foster more efficient and less-polluting energy sources, according to the latest NanoFrontiers newsletter, Nanotechnology: Energizing the Future. From nanotech-enabled solar panels to long-lasting automobile batteries that contain nanoparticles, the emerging technology is a cornerstone of 21st Century energy sources.

“We see a future where vehicles run on electricity and are equipped with clever ways of making electricity on board, making us less dependent on gasoline. It’s the next great paradigm shift in our industry, an opportunity largely due to the rapid advancement in battery cell technology” that results from nanotechnology, according to Bob Lutz, General Motors vice chairman of Global Product Development, who is quoted in the report.

A U.S. research team led by Chinese scientists has created a nanotube-based dry adhesive that surpasses the stickiness of gecko feet -- no easy feat, since the animals can cling to nearly any type of surface.

Geckos rely on aligned microscopic hairs for their gravity-defying climbs. Their design mimics this arrangement, with a vertically aligned array of straight carbon nanotubes topped by a layer of curly, entangled nanotubes, Wang Zhonglin, the lead researcher from Georgia Institute of Technology, told Xinhua on Thursday.

Just as in the gecko foot, the combination produces an adhesive with superior strength in the shear direction -- clinging against the pull of gravity -- and regular strength in the normal, perpendicular direction, which allows the adhesive to be easily pulled away from a surface. The shear adhesive force of the nanotube array is almost 10 times that of the gecko foot.

Though the material might seem most appropriate for use by Spider-man, the real applications may be less glamorous. Because carbon nanotubes conduct heat and electrical current, the bionic gecko feet could be used to connect electronic devices.

Another application might be for adhesives that work long-term in space. "In space, there is a vacuum and traditional kinds of adhesives dry out, but nanotube dry adhesives would not be bothered by the space environment," said Dai Liming, another lead researcher from University of Dayton.

Their paper will appear in the Oct issue of journal Science. For the future, the researchers hope to learn more about the surface interactions so they can further increase the adhesive force. They also want to study the long-term durability of the adhesive, which in a small number of tests became stronger with each attachment.