PORTLAND, Ore. Researchers at the Max Planck Institute (Munich, Germany) have developed a cell-transistor interface that they believe will usher in a new era of bioelectronics, allowing cells to be manipulated and studied without destroying them in the process.
In a demonstration prepared by institute biochemist Peter Fromherz, living cells were grown atop an array of transistors, thereby enabling the silicon chip to monitor the cell activity directly. The chip was used to test the effect of new drugs on the living cells. The results were then read out instantly from the chip, in an application that the researchers said could hasten drug development.
"We study the electrical interfacing of semiconductors and living cells," Fromherz said. "This basic research provides the basis for future applications in biosensors, medical prosthetics, brain research and neurocomputation."
Traditionally, living cells must be destroyed in order to study their inner workings. For instance, studying the effect of various drugs on serotonin levels in a cell has required application of a patch-clamp electrode to enable readout of the ion stream into and out of the cell. That technique slowly kills the cell, limiting the sample's usefulness to a few hours of tests.
Growing cells on a transistor array, by contrast, permits the cell-transistor interface to function as long as nutrients are supplied to the cell. In the Max Planck tests, the researchers first located the gate of the transistor that lay directly below the serotonin receptors on each living cell. When the receptor's ion channel opened to let the serotonin through, the voltage potential at the gate changed, modulating the transistor's source-drain current. The activity was recorded with computer-controlled monitoring circuitry.
The researchers were able to demonstrate that their interface could instantly evaluate the dosage/effect relationship of various drugs on serotonin. The computer control afforded by the interface suggested that whole batteries of drug discovery tests could be automated with such bioelectronic devices.
Now that the researchers have proved the concept, they plan to build more-universal test setups in a bid to harness living cells for other applications, such as toxin detection.