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Carbon nanotube absorption measured in worms, cancer cells
March 29, 2006ANN ARBOR, Mich.-University of Michigan researchers have discovered how to measure the absorption of multi-walled carbon nanoparticles into worms and cancer cells, a breakthrough that will revolutionize scientists' understanding of how the particles impact the living environment.
A team led by U-M chemical engineering professor Walter J. Weber Jr. tagged multi-walled carbon nanotubes-one of the most promising nanomaterials developed to date-with the carbon-14 radioactive isotope, which enabled the nanotubes to be tracked and quantified as they were absorbed into living cells. Researchers used cancer cells called HeLa cells, and also measured nanotube uptake in an earthworm and an aquatic type of worm.
The findings were presented Sunday at the 231st American Chemical Society National Meeting in Atlanta. Co-authors of the presentation are graduate student Elijah Petersen and postdoctoral research assistant Qingguo Huang.
Carbon nanotubes were discovered in 1991, and hold great promise in several areas, including pharmacology and for hydrogen storage in fuel cells, Weber said. But despite their promise, a big problem is that it's not known how multi-walled carbon nanotubes will impact the living environment, Weber said.
"While everyone is concerned about this issue, there has been no really adequate way before this development to examine the extent to which they may get into human cells, and what will result if they do," Weber said. "Nobody has been able to do quantitative research on this because no method to measure them has existed until now. We were able to detect them, but had no way to determine how much was there."
In tagging the nanotubes with the isotope, researchers found that about 74 percent of the nanotubes added to a culture of cancer cells were assimilated by the cells after 15 minutes, and 89 percent of nanotubes assimilated after six hours, according to the paper. And the uptake was nearly irreversible, with only about 0.5 percent of the nanotubes releases from the cell after 12 hours.
It's important to understand if and how the multi-walled carbon nanotubes accumulate in living cells, because before the materials can become widely used in society scientists must understand if they'll pass through the food webs and possibly threaten the health of ecosystems and lead to uptake by humans, Petersen said.
"This approach has virtually limitless potential for facilitating important future investigations of the behaviors of carbon nanotubes in environmental and biomedical applications," Petersen said.
The Regents of the University of Michigan
Carbon nanotubes were discovered in 1991, and hold great promise in several areas, including pharmacology and for hydrogen storage in fuel cells, Weber said. But despite their promise, a big problem is that it's not known how multi-walled carbon nanotubes will impact the living environment, Weber said.
"While everyone is concerned about this issue, there has been no really adequate way before this development to examine the extent to which they may get into human cells, and what will result if they do," Weber said. "Nobody has been able to do quantitative research on this because no method to measure them has existed until now. We were able to detect them, but had no way to determine how much was there."
In tagging the nanotubes with the isotope, researchers found that about 74 percent of the nanotubes added to a culture of cancer cells were assimilated by the cells after 15 minutes, and 89 percent of nanotubes assimilated after six hours, according to the paper. And the uptake was nearly irreversible, with only about 0.5 percent of the nanotubes releases from the cell after 12 hours.
It's important to understand if and how the multi-walled carbon nanotubes accumulate in living cells, because before the materials can become widely used in society scientists must understand if they'll pass through the food webs and possibly threaten the health of ecosystems and lead to uptake by humans, Petersen said.
"This approach has virtually limitless potential for facilitating important future investigations of the behaviors of carbon nanotubes in environmental and biomedical applications," Petersen said.
The Regents of the University of Michigan
Nanotube News and Current Nanotube Events RSSTrue properties of carbon nanotubes measured
For more than 15 years, carbon nanotubes (CNTs) have been the flagship material of nanotechnology. Researchers have conceived applications for nanotubes ranging from microelectronic devices to cancer therapy. Their atomic structure should, in theory, give them mechanical and electrical properties far superior to most common materials.
Slipping through cell walls, nanotubes deliver high-potency punch to cancer tumors in mice
The problem with using a shotgun to kill a housefly is that even if you get the pest, you'll likely do a lot of damage to your home in the process. Hence the value of the more surgical flyswatter.
Golden Scales: Nanoscale Mass Sensor from Berkeley Can Be Used to Weigh Individual Atoms and Molecules
There's a new "gold standard" in the sensitivity of weighing scales. Using the same technology with which they created the world's first fully functional nanotube radio, researchers with Berkeley Lab and the University of California (UC) at Berkeley have fashioned a nanoelectromechanical system (NEMS) that can function as a scale sensitive enough to measure the mass of a single atom of gold.
'Nanonet' circuits closer to making flexible electronics reality
Researchers have overcome a major obstacle in producing transistors from networks of carbon nanotubes, a technology that could make it possible to print circuits on plastic sheets for applications including flexible displays and an electronic skin to cover an entire aircraft to monitor crack formation.
Researchers generate hydrogen without the carbon footprint
A greener, less expensive method to produce hydrogen for fuel may eventually be possible with the help of water, solar energy and nanotube diodes that use the entire spectrum of the sun's energy, according to Penn State researchers.
LLNL researchers peer into water in carbon nanotubes
Researchers have identified a signature for water inside single-walled carbon nanotubes, helping them understand how water is structured and how it moves within these tiny channels.
The fight for the best quantum bit (qubit)
Our results give us, for the first time, the possibility to understand the interaction between just two electrons placed next to each other in a carbon nanotube.
Perfecting a solar cell by adding imperfections
Nanotechnology is paving the way toward improved solar cells. New research shows that a film of carbon nanotubes may be able to replace two of the layers normally used in a solar cell, with improved performance at a lower cost. Researchers have found a surprising way to give the nanotubes the properties they need: add defects.
Secret ingredient: nanoparticles aid bone growth
In the first study of its kind, bioengineers and bioscientists at Rice University and Radboud University in Nijmegen, Netherlands, have shown they can grow denser bone tissue by sprinkling stick-like nanoparticles throughout the porous material used to pattern the bone.
Brown researchers work toward ending cartilage loss
Scientists have long wrestled with how to aid those who suffer cartilage damage and loss. One popular way is to inject an artificial gel that can imitate cartilage's natural ability to act as the body's shock absorber. But that solution is temporary, requiring follow-up injections.
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