Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

'Label-free' imaging tool tracks nanotubes in cells, blood for biomedical research

06.12.2011
Researchers have demonstrated a new imaging tool for tracking structures called carbon nanotubes in living cells and the bloodstream, which could aid efforts to perfect their use in biomedical research and clinical medicine.

The structures have potential applications in drug delivery to treat diseases and imaging for cancer research. Two types of nanotubes are created in the manufacturing process, metallic and semiconducting. Until now, however, there has been no technique to see both types in living cells and the bloodstream, said Ji-Xin Cheng, an associate professor of biomedical engineering and chemistry at Purdue University.


Researchers have demonstrated a new imaging tool for tracking structures called single-wall carbon nanotubes in living cells and the bloodstream, work that could aid efforts to perfect their use in laboratory or medical applications. Here, the imaging system detects both metallic and semiconducting nanotubes, false-colored in red and green, in live hamster cells. (Weldon School of Biomedical Engineering, Purdue University)

The imaging technique, called transient absorption, uses a pulsing near-infrared laser to deposit energy into the nanotubes, which then are probed by a second near-infrared laser.

The researchers have overcome key obstacles in using the imaging technology, detecting and monitoring the nanotubes in live cells and laboratory mice, Cheng said.

"Because we can do this at high speed, we can see what's happening in real time as the nanotubes are circulating in the bloodstream," he said.

Findings are detailed in a research paper posted online Sunday (Dec. 4) in the journal Nature Nanotechnology.

The imaging technique is "label free," meaning it does not require that the nanotubes be marked with dyes, making it potentially practical for research and medicine, Cheng said.

"It's a fundamental tool for research that will provide information for the scientific community to learn how to perfect the use of nanotubes for biomedical and clinical applications," he said.

The conventional imaging method uses luminescence, which is limited because it detects the semiconducting nanotubes but not the metallic ones.

The nanotubes have a diameter of about 1 nanometer, or roughly the length of 10 hydrogen atoms strung together, making them far too small to be seen with a conventional light microscope. One challenge in using the transient absorption imaging system for living cells was to eliminate the interference caused by the background glow of red blood cells, which is brighter than the nanotubes.

The researchers solved this problem by separating the signals from red blood cells and nanotubes in two separate "channels." Light from the red blood cells is slightly delayed compared to light emitted by the nanotubes. The two types of signals are "phase separated" by restricting them to different channels based on this delay.

Researchers used the technique to see nanotubes circulating in the blood vessels of mice earlobes.

"This is important for drug delivery because you want to know how long nanotubes remain in blood vessels after they are injected," Cheng said. "So you need to visualize them in real time circulating in the bloodstream."

The structures, called single-wall carbon nanotubes, are formed by rolling up a one-atom-thick layer of graphite called graphene. The nanotubes are inherently hydrophobic, so some of the nanotubes used in the study were coated with DNA to make them water-soluble, which is required for them to be transported in the bloodstream and into cells.

The researchers also have taken images of nanotubes in the liver and other organs to study their distribution in mice, and they are using the imaging technique to study other nanomaterials such as graphene.

The paper was written by doctoral student Ling Tong; postdoctoral research associate Yuxiang Liu; doctoral students Bridget D. Dolash and Yookyung Jung; biomedical engineering research scientist Mikhail N. Slipchenko; Donald E. Bergstrom, the Walther Professor of Medicinal Chemistry; and Cheng.

The research is funded by the National Science Foundation.

Writer: Emil Venere, 765-494-4709, venere@purdue.edu

Source: Ji-Xin Cheng, 765-494-4335, jcheng@purdue.edu

Note to Journalists: Ji-Xin Cheng is pronounced "Gee-Shin." Journalists may obtain a copy of the research paper by contacting Nature at press@nature.com or calling 212-726-9231.

Related websites:

Purdue Weldon School of Biomedical Engineering

Purdue Department of Chemistry

Chen Yang

Emil Venere | EurekAlert!
Further information:
http://www.purdue.edu

More articles from Life Sciences:

nachricht New study finds distinct microbes living next to corals
22.05.2019 | Woods Hole Oceanographic Institution

nachricht Summit charts a course to uncover the origins of genetic diseases
22.05.2019 | DOE/Oak Ridge National Laboratory

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Self-repairing batteries

UTokyo engineers develop a way to create high-capacity long-life batteries

Engineers at the University of Tokyo continually pioneer new ways to improve battery technology. Professor Atsuo Yamada and his team recently developed a...

Im Focus: Quantum Cloud Computing with Self-Check

With a quantum coprocessor in the cloud, physicists from Innsbruck, Austria, open the door to the simulation of previously unsolvable problems in chemistry, materials research or high-energy physics. The research groups led by Rainer Blatt and Peter Zoller report in the journal Nature how they simulated particle physics phenomena on 20 quantum bits and how the quantum simulator self-verified the result for the first time.

Many scientists are currently working on investigating how quantum advantage can be exploited on hardware already available today. Three years ago, physicists...

Im Focus: Accelerating quantum technologies with materials processing at the atomic scale

'Quantum technologies' utilise the unique phenomena of quantum superposition and entanglement to encode and process information, with potentially profound benefits to a wide range of information technologies from communications to sensing and computing.

However a major challenge in developing these technologies is that the quantum phenomena are very fragile, and only a handful of physical systems have been...

Im Focus: A step towards probabilistic computing

Working group led by physicist Professor Ulrich Nowak at the University of Konstanz, in collaboration with a team of physicists from Johannes Gutenberg University Mainz, demonstrates how skyrmions can be used for the computer concepts of the future

When it comes to performing a calculation destined to arrive at an exact result, humans are hopelessly inferior to the computer. In other areas, humans are...

Im Focus: Recording embryonic development

Scientists develop a molecular recording tool that enables in vivo lineage tracing of embryonic cells

The beginning of new life starts with a fascinating process: A single cell gives rise to progenitor cells that eventually differentiate into the three germ...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

SEMANTiCS 2019 brings together industry leaders and data scientists in Karlsruhe

29.04.2019 | Event News

Revered mathematicians and computer scientists converge with 200 young researchers in Heidelberg!

17.04.2019 | Event News

First dust conference in the Central Asian part of the earth’s dust belt

15.04.2019 | Event News

 
Latest News

Summit charts a course to uncover the origins of genetic diseases

22.05.2019 | Life Sciences

New study finds distinct microbes living next to corals

22.05.2019 | Life Sciences

Stellar waltz with dramatic ending

22.05.2019 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>