Pasadena chemist wins national invention award

Chemist John D. Baldeschwieler of Pasadena, Calif., will be honored April 3 by the world's largest scientific society for developing new ways to "see" the structure and action of molecules - fundamental achievements that have led to new strategies for chemotherapy, for example. He will receive the 2001 Award for Creative Invention from the American Chemical Society at its 221st national meeting in San Diego.

Baldeschwieler's work is a good example of fundamental research with real-world impact. "I like to develop new methods for determining the structure and reactivity of molecules," says the chemistry and chemical engineering professor at the California Institute of Technology, Pasadena.

A technique his team developed has led to a new way to package and deliver chemotherapy agents to cancers. Liposome formulation - modifying liposomes, the body's packing boxes, to ferry drugs to their target - grew out of a technique called perturbed angular correlation spectroscopy, said Baldeschwieler. PAC can track not only the location of target molecules in a living, healthy animal, but their individual motions.

"As long as the liposome was intact, the small molecules (markers) inside tumbled rapidly," Baldeschwieler explained. "If it broke, they would bind and the tumbling rate went down."

That level of scrutiny allowed the researchers to develop a structure of liposome that could encapsulate a chemotherapy drug, survive the turbulence of blood circulation and deliver it to tumors through holes in their characteristically leaky blood vessels.

A $200-million-per-year industry in pharmaceuticals is based on liposome formulations, he said.

Baldeschwieler has also adapted technology from inkjet printers for a highly efficient and sensitive method to make DNA chips. The invention can spray hundreds of different DNA sequences on a small plate, and researchers can then screen mixtures for the presence of the particular DNA they wish to study.

Instead of the usual chemistry set, Baldeschwieler said, he preferred his erector set as a boy. "I've always really liked to build things," he said. "I enjoy three-dimensional structures. That's why I studied engineering as an undergraduate."

Baldeschwieler received his undergraduate degree from Cornell University in 1956 and his Ph.D. from the University of California, Berkeley, in 1959. He is a member of the ACS physical chemistry division.