Animal rights activists can breathe a sigh of relief with the advent of the latest drug testing technology. In lieu of lab rats, some researchers have now turned to testing medicines on microchips.
A mere few inches long, the silicon chip is designed to replicate a human organ and is imbued with the ability to mimic its major functions. Scientists configure the chips by pooling together all of the key cells housed in the organ -- for example, a kidney or a lung. From there they can test and observe the drug’s impact.
The revolutionary new technique could provide more comprehensive insight into how the medicine would affect humans than traditional methods of testing could. Not to mention this method would save millions of dollars in dead-end compounds. However, microchips have yet to be authorized by health regulators as to whether compounds tested on them are then safe enough to enter human trials.
Seeking a new asthma treatment, Boston-based Merck & Co. is commencing efforts to engineer a microchip that resembles a diseased lung. Though not an exact replica of the pulmonary organ, the microchip is a complex piece of technology that can capture many of the conditions that are impossible to achieve in an animal model.
Consisting of strips of transparent silicone rubber, the chip includes hollow channels through which air and fluid can pass. The channels are split by a flexible membrane lined with human lung tissue and blood-vessel cells. These cell walls can relax and contract with the application of suction.
Researchers at Harvard University's Wyss Institute for Biologically Inspired Engineering unveiled the lung-on-a-chip in 2010 and infected it by sending bacteria past the lung cells. They also afflicted the chip with pulmonary edema, or fluid on the lungs.
In cooperation with Wyss, drug maker GlaxoSmithKline found that the effect of a potential drug on the chip replicated the response seen in dog, mice and rat models of pulmonary edema.
In an article by the WSJ, Don Nicholson, who oversees Merck’s respiratory drug research, said he believes this technique can help scientists garner a better understanding of the biology behind asthma and identify candidates for certain medicines.
However, labs might want to hold onto their rats for a bit longer. A work in progress, the microchips still need to prove themselves to health regulators, though the promise of eliminating the limitations of animal testing is a promising possibility. Currently, only one out of every 10,000 tested compounds receives approval.
"There's a lot of additional work that's needed before these systems can replace our current methods to evaluate a drug's safety or effectiveness. The potential is there, however," Douglas Throckmorton, deputy director for regulatory science at the FDA's drug division said in the same article.
Following suit, other companies like AstraZeneca are considering using a liver microchip to observe how quickly a molecule gets metabolized in order to effectively determine drug dosage and avoid undesired side effects.
Edited by
Rich Steeves
