US regulators test organs-on-chips for food safety monitoring
The US Food and Drug Administration (FDA) has started testing whether livers-on-a-chip — miniature ‘organs’ engineered to mimic biological functions — can reliably model human reactions to food and foodborne illnesses. The experiments will help the agency to determine whether companies can substitute chip data for animal data when applying for approval of a new compound, such as a food additive, that could prove toxic. It is the first time a regulatory agency anywhere in the world has pursued organs-on-chips as an alternative to animal testing.
Suzanne Fitzpatrick, senior advisor for toxicology in the food science division of the FDA, announced the move in an 11 April blog post. Although the chips were designed for testing drugs, Fitzpatrick’s division wants to use them to see how individual organs process products such as dietary supplements and cosmetics. They will also be able to test how foodborne pathogens affect specific organs. FDA food safety scientists will first evaluate the human liver chip, before moving on to kidney, lung and intestine models.
The chips are made by Emulate, a biotechnology company in Cambridge, Massachusetts. The miniature organs contain multiple types of human liver cells grown on a scaffold, and constantly pump a blood-like fluid through the system to deliver nutrients and remove waste. Emulate CEO Geraldine Hamilton says that they can also include an immune-system-on-a chip to test how it affects liver metabolism.
A long way to go
“I’m excited that people are willing to try this new technology out,” says Lawrence Vernetti, a toxicologist at the University of Pittsburgh in Pennsylvania, who is developing a different kind of liver chip. Some aspects of animal metabolism are markedly different from humans: chocolate, for instance, is toxic to dogs’ livers. While animals are usually good models for predicting toxicity issues in humans, he says, they are not fool-proof. If the long-term goal is reducing the number of animals used for testing, “we have to come up with a system where regulators in science will trust the answers that will come out of it”, Vernetti says.
Vernetti says that he is surprised by how quickly regulators have begun testing the devices, but he says the decision is timely because of increasing pressure from the public to reduce the use of animals in research. In 2013, for instance, the European Union banned the sale of cosmetics that had been tested on animals. “You just can’t stop testing these things, you have to give an alternative,” Vernetti says. “These human-on-chip devices might be a nice answer.”
The announcement is a victory for animal-rights activists. “Animals don’t have to suffer through poisoning tests to improve healthcare for humans and we’re thrilled that the FDA is taking action,” says Kathy Guillermo, senior vice president of People for the Ethical Treatment of Animals in Washington DC, in a statement to Nature.
Still, it will be some time before organs-on-chips replace animal testing entirely. Hamilton points out that even if the human liver chip processes a toxin without incident, there could be unforeseen effects on other organs, such as the heart. Although researchers are working toward ways to link as many as 10 chips together, eliminating animal research entirely “is not in our sights right now,” Hamilton says. “We have a lot to do between now and then.”