Central Michigan University
(NHI Nanoblog) Potomac, Md. — Donald Tomalia wants to create what he calls a “common language” to help nanotechnology pioneers relate to biological and chemical researchers. He thinks he’s found the Rosetta stone, of sorts, through analyzing patterns displayed by nanoparticles — trends that, he hopes, can help create a kind of periodic table for nanomaterials, the super-tiny particles that acquire new properties and serve as building blocks for new super-medicines.
“These are real, fundamental building blocks that are just as precise at atoms, but they are nanoparticles,” Tomalia said.
Tomalia, the director of the National Dendrimer & Nanotechnology Center at Central Michigan University, and researchers at other institutions have been looking at all sorts of nanoparticles — including quantum dots, Fullerenes, and silica — and seeing similar things happen. The size of the particles, not the material, he said, seems to be a huge factor in behavior.
“Size defines almost everything,” Tomalia said. “No matter what the composition of these particles, size really seems to determine whether it’s excreted through the kidneys.”
Tomalia discussed his efforts at a conference jointly hosted by the American Society for Nanomedicine and National Institutes of Health’s Office of Aids Research and the Division of AIDS at the NIH’s National Institute of Allergy and Infectious Diseases. The main theme involved growing efforts to put nanotechnology to use in preventing and treating HIV, and eventually developing a vaccine for the infection.
A key finding, he said, is that “hard” nanoparticles, such as silica, gold and carbon nanotubes, and “soft” particles, such as dendrimers (spheric molecules with a treelike structure) and proteins, behave similarly.
During his talk, Tomalia discussed one experiment where scientists were able to trace particles as they moved through mice, finding that some particles went through the animal’s kidneys, and others through the liver, depending on the size. This type of finding, he said, could help researchers figure out which nanoparticles are safe — because they’ll leave the body completely — and which are going to stick around, potentially creating long-term problems.
Tomalis said a standard way of classifying nanoparticles could be an enormous help in the tricky task of ensuring that the super-small materials aren’t harming people or animals even as they treat disease. If scientists can count on size classifications, he added, it could save researchers the huge cost of having to test every single material for safety.
“It behooves everyone to try to keep their particles smaller,” Tomalia said. “If you want to make something larger, make it so it breaks down into something smaller.”
