From the article:
His lab uses mice for some protocols, but animal studies are notoriously bad at identifying human treatments. Around 95% of the drugs developed through animal research fail in people. Researchers have documented this translation gap since at least 1962. “All these pharmaceutical companies know the animal models stink,” says Don Ingber, founder of the Wyss Institute for Biologically Inspired Engineering at Harvard and a leading advocate for organs on chips. “The FDA knows they stink.”
All new compounds have to pass through a preclinical phase, where they’re tested for safety and effectiveness before moving to clinical trials in humans. Until recently, those tests had to run in at least two animal species—usually rats and dogs—before the drugs were tried on people.
But in December 2022, President Biden signed the FDA Modernization Act, which amended the original FDA Act of 1938. With a few small word changes, the act opened the door for non-animal-based testing in preclinical trials. Anything that makes it faster and easier for pharmaceutical companies to identify safe and effective drugs means better, potentially cheaper treatments for all of us.
“The capacity we have to test drugs is more or less fixed in this country,” says Shuler, whose company, Hesperos, also manufactures organs on chips. “There are only so many clinical trials you can do. So if you put a loser into the system, that means something that could have won didn’t get into the system. We want to change the success rate from clinical trials to a much higher number.”
Scientists have made liver chips, brain chips, heart chips, kidney chips, intestine chips, and even a female reproductive system on a chip (with cells from ovaries, fallopian tubes, and uteruses that release hormones and mimic an actual 28-day menstrual cycle). Each of these chips exhibits some of the specific functions of the organs in question. Cardiac chips, for instance, contain heart cells that beat just like heart muscle, making it possible for researchers to model disorders like cardiomyopathy.
Each chip starts with a physiologically based pharmacokinetic model, known as a PBPK model—a mathematical expression of how a chemical compound behaves in a human body. “We try and build a physical replica of the mathematical model of what really occurs in the body,” explains Shuler. That model guides the way the chip is designed, re-creating the amount of time a fluid or chemical stays in that particular organ—what’s known as the residence time. “As long as you have the same residence time, you should get the same response in terms of chemical conversion,” he says.
Tiny channels on each chip, each between 10 and 100 microns in diameter, help bring fluids and oxygen to the cells. “When you get down to less than one micron, you can’t use normal fluid dynamics,” says Shuler. And fluid dynamics matters, because if the fluid moves through the device too quickly, the cells might die; too slowly, and the cells won’t react normally.
Is this the end of animal testing?
https://www.technologyreview.com/2024/06/21/1093419/animal-testing-organ-on-chip-research/