Dredging The Digestive System; April 1997; Scientific American Magazine; by Gibbs; 1 Page(s)

Most drugs work by tinkering with the complex machinery of cells. Some interfere with the chemical messages cells send to one another. Others flip cellular switches to make them do something they normally wouldn¿t. However they work, the best drugs are usually those that home in on particular cells and tweak them in just one way.

So it might seem strange that GelTex Pharmaceuticals, a tiny six-year-old drug company in Waltham, Mass., is developing two drugs that it hopes will pass right through patients without directly affecting a single cell. GelTex¿s drugs are composed of polymers--huge molecules that are no more digestible than a bit of plastic wrap stuck to a hard candy.