Their invention, described in the June 20 issue of Langmuir, a physical chemistry journal published by the American Chemical Society, uses porous silicon crystals filled with polystyrene to detect subtle changes in the sizes and shapes of the cells.

"One of the big concerns with any potential new drug is its toxicity," says Michael Sailor, a professor of chemistry at biochemistry at UCSD who headed the research team. "Since the liver is the organ that cleans up the blood, liver cells are particularly susceptible when a toxin is introduced to the body. Pharmaceutical companies want to know early on the effect a drug has on the liver. But it's very expensive to screen every potential candidate on living animals, typically rats. So if you can use just a few cells from the liver rather than the entire animal, you can perform many more thorough tests."

"You could also in principle use this to identify metastatic cancer cells circulating in a patient's blood," Sailor adds, "by putting blood samples from a patient onto the crystal and comparing them to normal blood samples." In addition, says Michael Schwartz, a postdoctoral scholar in Sailor's laboratory and the first author of the paper: "The potential of our technique for fundamental studies of cell toxicity is exciting, Since we can monitor cells in real time without removing them from their natural environment, the observed changes provide a time course for performing more detailed tests to find out why drugs are toxic."

The scientists constructed their Smart Petri Dish by first fabricating silicon crystals with nanometer-sized holes. This enabled them to produce a photonic crystal, capable of controlling light within the
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Contact: Kim McDonald
kmcdonald@ucsd.edu
858-534-7572
University of California - San Diego
13-Jun-2006