"If you're inventing these sorts of materials, you need to be concerned about their impact," said Mark Banaszak Holl, a U-M professor of chemistry and of macromolecular science and engineering. "We're trying to do both: make important new materials and be excited about what can be done with them, but at the same time, understand what their potential downsides might be." Banaszak Holl and graduate students Pascale Leroueil and Seungpyo Hong will discuss their research at the 229th national meeting of the American Chemical Society in San Diego March 13-17.
In collaboration with other researchers at U-M's Center for Biologic Nanotechnology, Banaszak Holl's lab has been studying nanoparticles known as dendrimers, tiny spheres whose width is ten thousands times smaller than the thickness of a human hair. Dendrimers have shown promise for precisely delivering drugs to their targets inside the body, but high concentrations of these nanoparticles can be toxic. In earlier work, U-M researchers discovered that dendrimers punch nanoscale holes in cell membranes, making the membranes more permeable. At high enough concentrations, they can completely destroy the membranes, killing cells in the process. But the damage can be prevented by engineering dendrimers in particular ways, such as modifying their surfaces to make them neutral instead of charged, the scientists found. And, added Banaszak Holl, "not only does engineering make them less harmful, but it also makes them better at what we want them to do. You don't lose anything; it's all
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Contact: Nancy Ross-Flanigan
rossflan@umich.edu
734-647-1853
University of Michigan
15-Mar-2005