As the Trump administration halts the use of animal testing in the federal government, a biotech startup has a strong idea for an alternative to animal testing: insensitive “veterinary bags.”
Bay Area-based R3 Bio has been quietly pitching the idea to investors and internally industries publications as a way to replace laboratory animals without the ethical issues that come with living organisms. That’s because these structures would have all normal organs—except the brain, making them unable to think or feel pain. The company’s long-term goal, co-founder Alice Gilman says, is to develop human versions that can serve as a source of tissue and organs for people in need.
For Immortal Dragons, a Singapore-based longevity fund that has invested in R3, the idea of replacement is a core strategy for human longevity. “We think replacement is probably better than repair when it comes to treating disease or controlling the aging process in the human body,” says CEO Boyang Wang. “If we can create an emotionless, headless body in a human, that would be a great source of organs.”
Currently, R3 is focused on making monkey organ sacks. “The benefit of using models that are more ethical and are just organ systems would be that the testing can be worse,” Gilman says. (The name R3 comes from a philosophy in animal research known as The three Rs-substitution, reduction, and improvement -developed by British scientists William Russell and Rex Burch in 1959 to promote human experimentation.)
New drugs are often tested on monkeys before being given to human participants in clinical trials. For example, monkeys were important during the Covid-19 pandemic for testing vaccines and treatments. But they are also an expensive resource, and their numbers are declining in the United States after China banned the export of non-human primates in 2020.
Animal rights activists have long pushed for an end to research on monkeys, and one of only seven government-funded animal research centers across the country indicated would consider shutting down and moving to a sanctuary amid mounting pressure. The US Centers for Disease Control and Prevention is also finish the monkey studypart of a larger government-wide trend to reduce reliance on animal testing.
As a result, Gilman says, there aren’t enough research monkeys left in America to allow for the necessary research if another pandemic threat emerges. Enter the spice bags.
Container bags can in theory provide more benefits than existing ones organs-on-chips or tissue modelswhich does not have complete complexity of all organs, including blood vessels.
Gilman says it’s already possible to create mouse limb sacs that don’t have a brain, although he and co-founder John Schloendorn deny that R3 has done so. (For the record, Gilman doesn’t like the word “mindless” to describe organ sacs. “It doesn’t lack anything, because we’re building it just to have the things we want,” he says.) Gilman and Schloendorn won’t say exactly how they plan to create monkey sacs and human organs, but they said they’re exploring a combination of stem-cell technology and gene editing.
It is believed that organ sacs can be grown from pluripotent stem cells, says Paul Knoepfler, a stem cell biologist at the University of California, Davis. These stem cells come from adult skin cells and have been reprogrammed to an embryo-like state. They have the ability to form any cell or tissue in the body and have been used to form embryo-like structures similar to the real thing. By editing these stem cells, scientists can turn off genes needed for brain development. The resulting embryo can be activated until it develops into a structure of organized organs.
