BERKELEY, CA. -- Carolyn Bertozzi and her colleagues at the Ernest Orlando Lawrence Berkeley National Laboratory have found a way to use natural biological processes to plant artificial markers on the surfaces of living cells.
With these markers, cell surfaces can be engineered to control cell adhesion to synthetic organic polymers, metals, ceramics, and other materials used in the walls of bioreactors, and in biomedical implants such as pacemakers and artificial organs. In the future, living cells attached to electronic devices may warn of dangerous chemical or biological toxins in the environment. Already Bertozzi's group has used this cell-surface engineering to turn cancer cells into bright targets for diagnostic probes and cell-killing toxins.
"Our primary goal is to take control of the cell surface," says Bertozzi, who is a member of Berkeley Lab's Biomolecular Materials Program in the Materials Sciences Division, as well as an assistant professor of chemistry at the University of California at Berkeley. "We have begun to understand the bio-organic chemistry of cells well enough to treat cells like complex machines -- to really do cellular engineering."
All cell surfaces are decorated with oligosaccharides -- complex structures strung together inside the cell from a few simple sugars. Different kinds of cells display different oligosaccharides, and even the same kinds of cells display different patterns depending on their stage of development or environment. Since each oligosaccharide is chemically unique, each imparts to the cell a unique surface for interaction with the outside world.
"We asked ourselves, how can we exploit these differences?" says
Bertozzi. Working with graduate student Lara Mahal and postdoctoral fellow Kevin
Yarema, Bertozzi set out to design new cell surfaces that could stick to
synthetic materials. "We decided to appropriate the cell
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Contact: Paul Preuss
paul_preuss@lbl.gov
510-486-6249
DOE/Lawrence Berkeley National Laboratory
6-Jan-1998