March 14, 2006 | Source: Technology Review
University of Michigan physician and researcher James Baker has developed multipurpose nanoparticles precisely engineered to slip past barriers such as blood vessel walls, latch onto cancer cells, and trick the cells into engulfing them as if they were food. These Trojan particles flag the cells with a fluorescent dye and simultaneously destroy them with a drug.
The heart of Baker’s approach is a highly branched molecule called a dendrimer. Each dendrimer has more than a hundred molecular “hooks” on its surface. To five or six of these, Baker connects folic-acid molecules. Because folic acid is a vitamin, most cells in the body have proteins on their surfaces that bind to it. But many cancer cells have significantly more of these receptors than normal cells. Baker links an anticancer drug to other branches of the dendrimer; when cancer cells ingest the folic acid, they consume the deadly drugs as well.