New biochip could accelerate drug development
future drug development. The technology measures electrical
activities of cells and can obtain 60 times more data in one
reading than is possible with current technology.
Current technology being used in research labs is very slow and difficult and the hope is this biochip could accelerate drug development for muscle and nerve disorders like epilepsy, helping to create more productive crop varieties.
Researchers at Purdue University have been working on a device that measures the concentration of ions as they enter and exit cells.
The biochip records these concentrations in up to 16 living cells temporarily sealed within fluid-filled pores in the microchip. With four electrodes per cell, the chip delivers 64 simultaneous, continuous sources of data.
This data allows for a more detailed understanding of cellular activity compared to current technology, which measures only one point outside one cell and cannot record simultaneously.
"Instead of doing one experiment per day, as is often the case, this technology is automated and capable of performing hundreds of experiments in one day," said Marshall Porterfield, a professor of agricultural and biological engineering who leads the team developing the chip.
About 15 per cent of the drugs currently in development affect the activities of ion channels. Ion channels are particularly important in muscle and nerve cells, where they facilitate communication and the transfer of electrical signals from one cell to the next.
The chip also directly records ion concentrations without harming the cells, whereas present methods cannot directly detect specific ions, and cells being studied typically are destroyed in the process.
There are several advantages to retaining live cells such as being able to conduct additional tests or monitor them as they grow.
Within the 10-by-10 millimetre chip cells are sealed inside 16 pyramidal pores, analysed, and then can be removed intact. Since the technology does not kill the cells, it could be used to screen and identify different crop lines.
The current technology for analysing cells' electrical activity, called "patch clamping," which uses a tiny electrical probe viewed under a microscope. The technique requires a lot of know-how and hand-eye coordination
However, the chip is automated and could be mass-produced in the future. Such a readily available chip could record reams more data than patch clamping.
Ion channels and pumps establish a difference in electrical potential across a cell's membrane, which cells use to create energy and transfer electrical signals.
By quickly allowing ions in and out, they are useful for rapid cellular changes, the kind that occur in muscles, neurons and the release of insulin from pancreatic cells.
The chip currently can detect individual levels of different ions. Porterfield believes that with some modifications, however, the chip will be able to measure multiple ions at once and perform even more advanced functions such as electrically stimulating a cell with one electrode while recording the reaction with the remaining three.
Because ion channels are a prominent feature of the nervous system and elsewhere, they are a popular target for drugs. For example, lidocaine and Novocain target sodium-channels.
In nature, some of the most potent venoms and toxins work by blocking these channels, including the venom of certain snakes and strychnine.
The device is further described in an article in the journal Sensors and Actuators, published online this month and scheduled to appear in the print edition in November.
