Nanotubes used for first time to send signals to nerve cellsMay 09, 2006GALVESTON, Texas -Texas scientists have added one more trick to the amazing repertoire of carbon nanotubes - the ability to carry electrical signals to nerve cells. Nanotubes, tiny hollow carbon filaments about one ten-thousandth the diameter of a human hair, are already famed as one of the most versatile materials ever discovered. A hundred times as strong as steel and one-sixth as dense, able to conduct electricity better than copper or to substitute for silicon in semiconductor chips, carbon nanotubes have been proposed as the basis for everything from elevator cables that could lift payloads into Earth orbit to computers smaller than human cells. Thin films of carbon nanotubes deposited on transparent plastic can also serve as a surface on which cells can grow. And as researchers at the University of Texas Medical Branch at Galveston (UTMB) and Rice University suggest in a paper published in the May issue of the Journal of Nanoscience and Nanotechnology, these nanotube films could potentially serve as an electrical interface between living tissue and prosthetic devices or biomedical instruments. "As far as I know, we're the first group to show that you can have some kind of electrical communication between these two things, by stimulating cells through our transparent conductive layer," said Todd Pappas, director of sensory and molecular neuroengineering at UTMB's Center for Biomedical Engineering and one of the study's senior authors. Pappas and UTMB research associate Anton Liopo collaborated on the work with James Tour, director of the Carbon Nanotechnology Laboratory at Rice's Richard E. Smalley Institute for Nanoscale Science and Technology, Rice postdoctoral fellow Michael Stewart and Rice graduate student Jared Hudson. The group employed two different types of cells in their experiments, neuroblastoma cells commonly used in test-tube experiments and neurons cultured from experimental rats. Both cell types were placed on ten-layer-thick "mats" of single-walled carbon nanotubes (SWNTs) deposited on transparent plastic. This enabled the researchers to use a microscope to position a tiny electrode next to individual cells and record their responses to electrical pulses transmitted through the SWNTs. In addition to their electrical stimulation experiments, the scientists also studied how different kinds of SWNTs affected the growth and development of neuroblastoma cells. They compared cells placed on mats made of "functionalized" SWNTs, carbon nanotubes with additional molecules attached to their surfaces that may be used to guide cell growth or customize nanotube electrical properties, to cells cultured on unmodified "native" carbon nanotubes and conventional tissue culture plastic. "Native carbon nanotubes support neuron attachment and growth well - as we expected, better than the two types of functionalized nanotubes we tested," Pappas said. "Next we want to find a way to functionalize the nanotubes to make neuron attachment and communication better and make these surfaces more biocompatible." Another avenue Pappas wants to explore is finding out whether nanotubes are sensitive enough to record ongoing electrical activity in cells. "Where we want to get to is a device that can both sense and deliver stimuli to cells for things like prosthetic control," Pappas said. "I think it's definitely doable, and we're pursuing that with Jim Tour and his group. It's great to be able to work with a guy who's on the cutting edge of nanoelectronics technology - he seems to develop something new every week, and it's really become a great interaction." University of Texas Medical Branch at Galveston |
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| Related Nanotubes Current Events and Nanotubes News Articles New study confirms exotic electric properties of graphene First, it was the soccer-ball-shaped molecules dubbed buckyballs. Then it was the cylindrically shaped nanotubes. Now, the hottest new material in physics and nanotechnology is graphene: a remarkably flat molecule made of carbon atoms arranged in hexagonal rings much like molecular chicken wire. Caltech scientists develop DNA origami nanoscale breadboards for carbon nanotube circuits In work that someday may lead to the development of novel types of nanoscale electronic devices, an interdisciplinary team of researchers at the California Institute of Technology (Caltech) has combined DNA's talent for self-assembly with the remarkable electronic properties of carbon nanotubes, thereby suggesting a solution to the long-standing problem of organizing carbon nanotubes into nanoscale electronic circuits. Breakthrough in industrial-scale nanotube processing Rice University scientists today unveiled a method for the industrial-scale processing of pure carbon-nanotube fibers that could lead to revolutionary advances in materials science, power distribution and nanoelectronics. Next-generation microcapsules deliver 'chemicals on demand' Scientists in California are reporting development of a new generation of the microcapsules used in carbon-free copy paper, in which capsules burst and release ink with pressure from a pen. Transforming Nanowires Into Nano-Tools Using Cation Exchange Reactions A team of engineers from the University of Pennsylvania has transformed simple nanowires into reconfigurable materials and circuits, demonstrating a novel, self-assembling method for chemically creating nanoscale structures that are not possible to grow or obtain otherwise. Study shows how carbon nanotubes can affect lining of the lungs Carbon nanotubes are being considered for use in everything from sports equipment to medical applications, but a great deal remains unknown about whether these materials cause respiratory or other health problems. Advance in 'nano-agriculture': Tiny stuff has huge effect on plant growth With potential adverse health and environmental effects often in the news about nanotechnology, scientists in Arkansas are reporting that carbon nanotubes (CNTs) could have beneficial effects in agriculture. A step toward better brain implants using conducting polymer nanotubes Brain implants that can more clearly record signals from surrounding neurons in rats have been created at the University of Michigan. The findings could eventually lead to more effective treatment of neurological disorders such as Parkinson's disease and paralysis. A recipe for controlling carbon nanotubes Nanoscopic tubes made of a lattice of carbon just a single atom deep hold promise for delivering medicines directly to a tumor, sensors so keen they detect the arrival or departure of a single electron, a replacement for costly platinum in fuel cells or as energy‐saving transistors and wires. Friction force differences could offer a new means for sorting and assembling nanotubes Nanotubes and nanowires are promising building blocks for future integrated nanoelectronic and photonic circuits, nanosensors, interconnects and electro-mechanical nanodevices. But some fundamental issues remain to be resolved - among them, how to position and manipulate the tiny tubes. More Nanotubes Current Events and Nanotubes News Articles |
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