Tag Archives: Science as Art

Hitchhikers at the nanoscale show how cells stir themselves

A May 30, 2014 news item on Nanowerk highlights some molecule-tracking research,

Chemical engineers from Rice University and biophysicists from Georg-August Universität Göttingen in Germany and the VU University Amsterdam in the Netherlands have successfully tracked single molecules inside living cells with carbon nanotubes.

Through this new method, the researchers found that cells stir their interiors using the same motor proteins that serve in muscle contraction.

A May 29, 2014 Rice University news release by Mike Williams, which originated the news item, describes the researchers’ work,

The team attached carbon nanotubes to transport molecules known as kinesin motors to visualize and track them as they moved through the cytoplasm of living cells.

Carbon nanotubes are hollow cylinders of pure carbon with one-atom-thick walls. They naturally fluoresce with near-infrared wavelengths when exposed to visible light, a property discovered at Rice by Professor Rick Smalley a decade ago and then leveraged by Rice Professor Bruce Weisman to image carbon nanotubes. When attached to a molecule, the hitchhiking nanotubes serve as tiny beacons that can be precisely tracked over long periods of time to investigate small, random motions inside cells.

“Any probe that can hitch the length and breadth of the cell, rough it, slum it, struggle against terrible odds, win through and still know where its protein is, is clearly a probe to be reckoned with,” said lead author Nikta Fakhri, paraphrasing “The Hitchhiker’s Guide to the Galaxy.” Fakhri, who earned her Rice doctorate in Pasquali’s lab in 2011, is currently a Human Frontier Science Program Fellow at Göttingen.

“In fact, the exceptional stability of these probes made it possible to observe intracellular motions from times as short as milliseconds to as long as hours,” she said.

For long-distance transport, such as along the long axons of nerve cells, cells usually employ motor proteins tied to lipid vesicles, the cell’s “cargo containers.” This process involves considerable logistics: Cargo needs to be packed, attached to the motors and sent off in the right direction.

“This research has helped uncover an additional, much simpler mechanism for transport within the cell interior,” said principal investigator Christoph Schmidt, a professor of physics at Göttingen. “Cells vigorously stir themselves, much in the way a chemist would accelerate a reaction by shaking a test tube. This will help them to move objects around in the highly crowded cellular environment.”

The researchers showed the same type of motor protein used for muscle contraction is responsible for stirring. They reached this conclusion after exposing the cells to drugs that suppressed these specific motor proteins. The tests showed that the stirring was suppressed as well.

The mechanical cytoskeleton of cells consists of networks of protein filaments, like actin. Within the cell, the motor protein myosin forms bundles that actively contract the actin network for short periods. The researchers found random pinching of the elastic actin network by many myosin bundles resulted in the global internal stirring of the cell. Both actin and myosin play a similar role in muscle contraction.

The highly accurate measurements of internal fluctuations in the cells were explained in a theoretical model developed by VU co-author Fred MacKintosh, who used the elastic properties of the cytoskeleton and the force-generation characteristics of the motors.

“The new discovery not only promotes our understanding of cell dynamics, but also points to interesting possibilities in designing ‘active’ technical materials,” said Fakhri, who will soon join the Massachusetts Institute of Technology faculty as an assistant professor of physics. “Imagine a microscopic biomedical device that mixes tiny samples of blood with reagents to detect disease or smart filters that separate squishy from rigid materials.”

There is an accompanying video,

This video is typical of the kind of visual image that nanoscientists look at and provides an interesting contrast to ‘nano art’ where colours and other enhancements are added. as per this example, NanoOrchard, from a May 13, 2014 news item on Nanowerk about the 2014 Materials Research Society spring meeting and their Science as Art competition,

NanoOrchard – Electrochemically overgrown CuNi nanopillars. (Image courtesy of the Materials Research Society Science as Art Competition and Josep Nogues, Institut Catala de Nanociencia i Nanotecnologia (ICN2), Spain, and A. Varea, E. Pellicer, S. Suriñach, M.D. Baro, J. Sort, Univ. Autonoma de Barcelona) [downloaded from http://www.nanowerk.com/nanotechnology-news/newsid=35631.php]

NanoOrchard – Electrochemically overgrown CuNi nanopillars. (Image courtesy of the Materials Research Society Science as Art Competition and Josep Nogues, Institut Catala de Nanociencia i Nanotecnologia (ICN2), Spain, and A. Varea, E. Pellicer, S. Suriñach, M.D. Baro, J. Sort, Univ. Autonoma de Barcelona) [downloaded from http://www.nanowerk.com/nanotechnology-news/newsid=35631.php]

Getting back to the carbon nanotube hitchhikers, here’s a link to and a citation for the paper,

High-resolution mapping of intracellular fluctuations using carbon nanotubes by Nikta Fakhri, Alok D. Wessel, Charlotte Willms, Matteo Pasquali, Dieter R. Klopfenstein, Frederick C. MacKintosh, and Christoph F. Schmidt. Science 30 May 2014: Vol. 344 no. 6187 pp. 1031-1035 DOI: 10.1126/science.1250170

This article is behind a paywall.

One final comment, I am delighted by the researcher’s reference to the Hitchhiker’s Guide to the Galaxy.

Pacific Northwest National Laboratory gets artistic

There are some very pretty pictures from the Pacific Northwest National Laboratory (PNNL) that appear in a new calendar featuring science as art. From the Nov. 1, 2011 news item on Nanowerk,

A dozen stunning science images, representing cell structures, microorganisms, polymer films, degraded metals and more, have been selected by the voting public as winners in Pacific Northwest National Laboratory’s Science as Art contest.

The photos are representative of research projects at the Department of Energy laboratory and will appear in a 2012 “Discovery in Action” calendar (available for high- and low-resolution download). Winning images will also be used in laboratory websites, printed materials, building lobbies and conference rooms.

You can find out more about the competition in the news item and/or you can also view the images on the PNNL’s Flickr site. I downloaded a couple samples from the Flickr site,

Electro-Polymerization of Pyrrole

Electro-Polymerization of Pyrrole
Organizations like the U.S. Environmental Protection Agency rely on field sensors that can detect traces of anionic water-soluble pollutants, like arsenate, chromate, perchlorate and pertechnetate. At PNNL, scientists are experimenting with modified polymer films that can recognize—and therefore be used—to detect pollutants. These polymers could potentially be incorporated into devices that would make detection rapid and economic. Shown here is a microscopic image of a polymer film generated through electro-polymerization of pyrrole from a water solution. PNNL researchers Dev Chatterjee, Thao Bui and Sam Bryan are working on this project.

and here’s the second one,

Designing Nano-Potteries: CdS Hollow Spheres

Designing Nano-Potteries: CdS Hollow Spheres
Imaging bio-molecules and cells over extended periods of time is critical to understanding cellular processes and the causes of pathogenic diseases. Cadmium sulfide quantum dots are widely used for highly sensitive cellular imaging. The extraordinary photostability of these probes are highly attractive for the real-time tracking of bio-molecules and cells over time. PNNL scientists are exploring quantum dots with varying morphologies and trying to understand the variation of their spectroscopy associated with the morphological changes. The goal is to design probes that can be used to monitor cellular processes over extended periods. PNNL researcher Dev Chatterjee provided the image. Others who contribute to the project include Matthew Edwards, Paul MacFarlan, Samuel Bryan and Jason Hoki. Image colored by PNNL graphic designer Jeff London.

I quite enjoyed the images.

Latest MRS Science as Art images

The Materials Research Society (MRS) holds a “Science as Art” competition for its Spring and Fall meetings. First place and second place winners for the Fall 2010 meeting are being featured in a Jan. 22, 2011 news item on Nanowerk.  I’ve copied two images as a sampler of what you can find on Nanowerk.

Stem of nanoflowers. SThis picture is created from a high resolution SEM image of zinc oxide "nanoflowers" synthesized by a physical vapor deposition technique. (Image: Abhishek Prasad, Michigan Technological University)

Then there’s this one,

Aurora Zinc Oxide. This picture was created from the convergence of a high-resolution cross-sectional and a plan view SEM image of a zinc oxide "nanowall structure" synthesized by a metal-organic chemical vapor deposition technique. Color was added to the original image. (Image: Dong Chan Kim, Sungkyunkwan University)

Gorgeous, aren’t they? If you are interested in seeing of the “Science as Art” competition winners from all the years of competition, you can go here.