David Kirkpatrick

June 11, 2010

Friday video fun — graphene into fullerene

This time it’s fun with science watching graphene turn into buckyballs.

PhysOrg has an article covering this video with additional images.

From the link:

Peering through a transmission electron microscope (TEM), researchers from Germany, Spain, and the UK have observed graphene sheets transforming into spherical fullerenes, better known as buckyballs, for the first time. The experiment could shed light on the process of how fullerenes are formed, which has so far remained mysterious on the atomic scale.

“This is the first time that anyone has directly observed the mechanism of fullerene formation,” Andrei Khlobystov of the University of Nottingham toldPhysOrg.com. “Shortly after the discovery of fullerene (exactly 25 years ago), the ‘top down’ mechanism of fullerene assembly was proposed. However, it was soon rejected in favor of a multitude of different ‘bottom up’ mechanisms, mainly because people could not understand how a flake of  could form a fullerene and because they did not have means to observe the fullerene formation in situ.”

March 17, 2010

DNA nanotubes as a drug delivery system

Medical nanotech news from McGill University.

The release:

DNA nanotechnology breakthrough offers promising applications in medicine

McGill researchers create DNA nanotubes able to carry and selectively release materials

This release is available in French.

A team of McGill Chemistry Department researchers led by Dr. Hanadi Sleiman has achieved a major breakthrough in the development of nanotubes – tiny “magic bullets” that could one day deliver drugs to specific diseased cells. Sleiman explains that the research involves taking DNA out of its biological context. So rather than being used as the genetic code for life, it becomes a kind of building block for tiny nanometre-scale objects.

Using this method, the team created the first examples of DNA nanotubes that encapsulate and load cargo, and then release it rapidly and completely when a specific external DNA strand is added. One of these DNA structures is only a few nanometres wide but can be extremely long, about 20,000 nanometres. (A nanometre is one-10,000th the diameter of a human hair.)

Until now, DNA nanotubes could only be constructed by rolling a two-dimensional sheet of DNA into a cylinder. Sleiman’s method allows nanotubes of any shape to be formed and they can either be closed to hold materials or porous to release them. Materials such as drugs could then be released when a particular molecule is present.

One of the possible future applications for this discovery is cancer treatment. However, Sleiman cautions, “we are still far from being able to treat diseases using this technology; this is only a step in that direction. Researchers need to learn how to take these DNA nanostructures, such as the nanotubes here, and bring them back to biology to solve problems in nanomedicine, from drug delivery, to tissue engineering to sensors,” she said.

The team’s discovery was published on March 14, 2010 in Nature Chemistry. The research was made possible with funding from the National Science and Engineering Research Council and the Canadian Institute for Advanced Research.


On the Web: http://www.hanadisleiman.com

Video link: http://snurl.com/uw2q1