As the Trump administration phases out the use of animal testing in the federal government, a biotech startup has a bold idea for an alternative to animal testing: non-sentient “organ bags.”
Bay Area-based R3 Bio quietly pitched the idea to investors and, in industry publications as a way to replace laboratory animals without the ethical problems associated with living organisms. This is because these structures would contain all the typical organs except a brain, making them incapable of thinking or feeling pain. The company’s long-term goal, according to co-founder Alice Gilman, is to create human versions that could be used as a source of tissues and organs for people who need them.
For Immortal Dragons, a Singapore-based longevity fund that invests in R3, the idea of replacement is a fundamental strategy for human longevity. “We believe that replacement is probably better than repair when it comes to treating diseases or regulating the aging process of the human body,” says Boyang Wang, CEO. “If we can create an unsentient, headless bodyoid for a human being, that will be a great source of organs.”
For now, R3 aims to make monkey organ bags. “The advantage of using more ethical models and exclusively organ systems would be that the tests could be much more scalable,” says Gilman. (The name R3 comes from the animal research philosophy known as three R(replacement, reduction and refinement) 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 humans in clinical trials. For example, monkeys played a vital role during the Covid-19 pandemic in testing vaccines and therapeutics. But they are also an expensive resource, and their numbers have been declining in the United States since China banned the export of non-human primates in 2020.
Animal rights activists have long campaigned to end monkey research, and one of seven federally funded primate research centers across the country has reported it would consider closing its doors and becoming a sanctuary in the face of growing pressure. The U.S. Centers for Disease Control and Prevention is also put an end to monkey researchwhich is part of a wider trend within the government to reduce the use of animal testing.
As a result, Gilman says, there aren’t enough research monkeys left in the United States to enable necessary research if another pandemic threat emerges. Enter organ bags.
Organ bags would in theory offer advantages over organs on chips or tissue modelswhich lack all the complexity of entire organs, including blood vessels.
Gilman says it’s already possible to create bags of brainless mouse organs, although she and co-founder John Schloendorn deny that R3 made them. (For the record, Gilman doesn’t like the term “brainless” to describe the organ bags. “There’s nothing missing, because we design it to hold only the things we want,” she said.) Gilman and Schloendorn wouldn’t say exactly how they plan to create the ape and human organ bags, but said they are exploring a combination of stem cell technology and gene editing.
It’s plausible that bags of organs could be grown from induced 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 are reprogrammed to an embryonic state. They have the potential to transform into any cell or tissue in the body and have been used to create embryo-like structures which resembles reality. By modifying these stem cells, scientists could turn off the genes necessary for brain development. The resulting embryo could then be incubated until it developed into organized organic structures.
Gilman envisions the monkey organ bags initially being used to test drug toxicity. Eliminating the pain and suffering felt by research animals is a major motivation for the startup.
American animal protection law need minimize the pain and distress of research animals, but this is not always possible. In fiscal 2024, U.S. research centers reported using more than 60,000 nonhuman primates for testing and experimentation, according to the Animal and phytosanitary inspection servicewhich is part of the Ministry of Agriculture. More than 33,000 of these animals experienced no pain, while nearly 26,000 experienced minimal pain. For approximately 1,200 of these animals, pain was not minimized due to the nature of the experiments. The federal government does not keep statistics on the number of non-human primates euthanized each year as a result of research.
R3’s ambitions, however, go beyond replacing animal testing. The company is considering the replacement of human parts, a emerging idea in the area of longevity. The startup aims to create bags of non-sentient human organs that could provide blood, tissues and organs to people when their own bodies fail them.
“We have things that no one has invented before to create custom organs,” says Gilman, who was inspired in part by her father’s experience having a heart transplant. Around the world, the demand for organ donors exceeds the supply. In the United States alone, more than 100,000 people are waiting for an organ transplant and 13 people die every day while waiting for a transplant.
Gilman highlights well-documented illegal trade in organ harvesting Asia And Africa as the reason why ethically sourced body parts are desperately needed. In the United States, a survey last year by the Department of Health and Human Services, alleged cases in which hospitals allowed the organ procurement process to begin when some patients may still have neurological signs compatible with life.
Genetically modified pig organs are being studied as a way to help alleviate the organ shortage. But so far, the longest a person has lived with a pig organ is just under nine months.
Growing human organs from scratch is a long-standing goal of regenerative medicine, but the idea of body bags raises a number of ethical questions about how these entities would be created, stored and maintained – and whether they would be capable of consciousness or feeling pain.
“If you create a living entity with no brain at all, I think we would be pretty comfortable thinking that it can’t feel pain,” says Hank Greely, a bioethicist at Stanford University, who written on the potential for human “bodyoids” lacking sentience. “It’s quite possible that none of this will ever work, but it’s also possible that it will work.”
Greely thinks it will be important to get public buy-in because the concept is very troubling. “I think the yuck factor will be strong,” he says, “but part of it depends on how the resulting things look and behave.”
This all still remains very theoretical. R3 says it currently only works on monkey cells, although a job posting posted by Gilman shows the company is looking for a veterinarian in Puerto Rico to “implant embryos, monitor pregnancies, and assist in healthy births” in nonhuman primates. Besides Immortal Dragons, the company is backed by billionaire Tim Draper and LongGame Ventures in the United Kingdom, according to R3.
“We are all better off than we were 150 years ago,” Draper told WIRED via email, “and thanks to forward-thinking entrepreneurs, we will be much better off 150 years from now.”