Princeton engineers have developed a sensor that may revolutionize how drugs and medical devices are tested for contamination, and in the process also help ensure the survival of two species of threatened animals.
To be fair, some of the credit goes to an African frog.
In the wild, the African clawed frog produces antibacterial peptides -- small chains of amino acids -- on its skin to protect it from infection. Princeton researchers have found a way to attach these peptides, which can be synthesized in the laboratory, to a small electronic chip that emits an electrical signal when exposed to harmful bacteria, including pathogenic E. coli and salmonella.
"It's a robust, simple platform," said Michael McAlpine, an assistant professor of mechanical and aerospace engineering and the lead researcher on the project. "We think these chips could replace the current method of testing medical devices and drugs."
A paper outlining their development of the sensor was published online October 18 in the Proceedings of the National Academy of Science. The research was funded by the American Asthma Foundation and by the Air Force Office of Scientific Research.
The current testing method has a major drawback: It relies on the blood of the horseshoe crab, a species that is roughly 450 million years old. The horseshoe crab population has declined in recent years, and as a result, so too has the population of a bird that feasts on the crab.
The crab became desirable for testing because its immune system has evolved to cope with the constant threat of invasion from its bacteria-rich environment. Its blood contains antimicrobial cells, known as amebocytes, that defend the crab against bacteria -- similar to the way the peptides protect the African frog's skin.
For almost 40 years, an aqueous extract made from horseshoe crab blood cells, called Limulus amebocyte lysate (LAL), has been used for testing drugs
|Contact: Chris Emery|
Princeton University, Engineering School