A "Smart" Petri Dish? Using Nanotechnology for Mass Screening of Liver Toxins

Welcome back to Snowcrash of Biosingularity Blog, who had taken some time off from blogging for several weeks. Snowcrash reveals that researchers at UCSD have developed a "smart petri dish" using silicon crystals pierced by nanometer sized holes. These dishes are designed to maintain a culture of liver cells, and allow for mass screening of liver toxins and toxic drug interactions, and more.

Researchers at the University of California, San Diego have developed what they call a “Smart Petri Dish” that could be used to rapidly screen new drugs for toxic interactions or identify cells in the early stages of cancer circulating through a patient’s blood.

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.”

....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 structure analogous to the way that semiconductors transmit electricity through computer chips. By attaching rat liver cells to the polystyrene within the crystals and measuring the scattering of light with a sensitive spectrometer, they were able to detect small changes in the shapes of the cells as they reacted to toxic doses of cadmium chloride and acetaminophen.

“As these cells shrivel up in response to a toxin, they scatter light better, much like fog on a car windshield, allowing us to quicklydetect which drugs may have adverse side effects when taken in combination with another,” says Sailor. “You’re not supposed to drink alcohol when taking acetaminophen, because the combination of the two is much more toxic to your liver than either drug individually. This is known as an adverse drug-drug interaction and it is very expensive and time-consuming to screen a new drug candidate with all the possible combinations of drugs that a patient may be taking. The Smart Petri Dish allows us to perform a large number of such toxicity assays simultaneously, in order to provide an early indication of the particular physiological or pharmacological conditions that need more in-depth study.” More at Biosingularity.

It is fascinating to contemplate how many of the tools of research, and everyday life for that matter, could be made more intelligent by nano-fabrication methods combined with laser/light, RFID, and nanoelectronics.

Soon we will be developing "grist", the intelligent nanomatter that permeates the science fiction world of Tony Daniel's "Metaplanetary" and "Supraluminal." There are still a few technicalities to work out, but as long as western civilisation exists as the foundation for scientific research, it is likely that we will get there eventually.