Stem cell research has been a controversial topic since the moment the technology was conceived.
But now, it looks like it will receive a break in Japan, thanks to a newly-approved study. But the question still remains, at what cost?
Pig-human hybrid embryo from previous experiment that was not brought to term - Juan Carlos Izpisua Belmonte
For years, Japanese stem cell biologist Hiromitsu Nakauchi has been planning a study using the technology. He doesn't just want to use it in previous ways either. Instead, he wants to use stem cells to pursue human-animal embryo experiments.
That's right, he's going to graft human stem cells into animal embryos.
Most countries have either restricted or outright banned this practice given how ethically dubious it is. Japan however just lifted the restriction earlier this year, making it legal to not just transplant hybrid embryos into animals to study them, but also to bring them to term.
Stem cells - Wikimedia Commons
The idea is that we could use this research to grow customised human organ replacements in animals like sheep and pigs, effectively creating organ farms. That's great news for the millions of people across the world waiting for organs on transplant lists. This practice could make the process cheaper and faster, saving lives. Of course, there's also the ethical dilemma of using animals in this way, which you can be certain will come up for debate.
And in the meantime, we also need to figure out what other sort of complications this practice could raise. Nakauchi is the first Japanese researchers to receive approval for this kind of study since the ban came into effect in 2014, so he says he's planning to take things slow in order for the general public to acclimate to it.
"We don't expect to create human organs immediately, but this allows us to advance our research based upon the know-how we have gained up to this point," he told The Asahi Shimbun.
The experiments will see Nakauchi injecting human-induced pluripotent stem cells into rat and mice embryos, which have themselves been genetically manipulated so they can't form pancreases in the babies. The idea is to see whether the stem cells can instead be used by the embryo to build a pancreas replacement that's enduring.
If that happens, it holds promise for animal-grown human organ replacements, and the researchers will then move on to experiments with pigs.?
Wikimedia Commons
However there's no guarantee the stem cells will grow into exactly what they want, which is a pancreas. So if the researchers detect that more than 30 percent of the rodent brains in the fetuses are human, they will suspend the experiment. That's part of the government's stipulation to prevent a "humanised" animal from ever coming into existence.
"We are trying to ensure that the human cells contribute only to the generation of certain organs," Nakauchi explained to Stanford Medicine's Out There.
"With our new, targeted organ generation, we don't need to worry about human cells integrating where we don't want them, so there should be many fewer ethical concerns."