The most critical tests, say the researchers, were those involving E. coli, which were conducted to assess the material's interactions with living cells. In the presence of E. coli, some strains of which are food-borne pathogens, the nanotubes turned shades of red and pink. Moreover, with the aid of an electron microscope, the researchers observed the tubes piercing the membranes of the bacteria like a needle being inserted into the cell. Both the polymerized (those that can change color) and the unpolymerized nanotube structures were effective antimicrobials, completely killing all the E. coli within an hour's time.

"We are very encouraged by these results and we will be continuing our investigations of this novel material in collaboration with our colleagues here at the University of Pittsburgh and the U.S. Army Research Office," added Dr. Russell.

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Contact: Lisa Rossi
RossiL@upmc.edu
412-647-3555
University of Pittsburgh Medical Center
24-Sep-2004