Medical staff rushing organs to a surgery for transplantation.
Thanks to the remarkable evolution of organ transplantation, it's now possible to replace genitals that don't work properly or have been injured. Surgeons have been transplanting ovarian tissue for more than a decade, and they're now successfully transplanting penises and wombs too.
Rules and regulations aren't keeping up with the rapid rise of genital transplants.
Earlier this year, an American soldier whose genitals were injured by a bomb in Afghanistan received the first-ever transplant of a penis and scrotum at Johns Hopkins Medicine.
Rules and regulations aren't keeping up with the rapid rise of genital transplants, however, and there's no consensus about how society should handle a long list of difficult and delicate questions.
Are these expensive transplants worth the risk when other alternatives exist? Should men, famously obsessed with their penises, be able to ask for a better model simply because they want one? And what happens when transplant technology further muddles the concept of biological parenthood?
"We need to remember that the human body is not a machine with interchangeable parts," says bioethicist Craig M. Klugman of DePaul University. "These are complicated, difficult and potentially dangerous surgeries. And they require deep consideration on a physical, psychological, spiritual, and financial level."
From Extra Testicles to Replacement Penises
Tinkering with human genitalia -- especially the male variety -- is hardly a new phenomenon. A French surgeon created artificial penises for injured soldiers in the 16th century. And a bizarre implant craze swept the U.S. in the 1930s when a quack physician convinced men that, quite literally, the more testicles the merrier – and if the human variety wasn't available, then ones from goats would have to do.
Now we're more sophisticated. Modern genital transplants are designed to do two things: Treat infertility (in women) and restore the appearance and function of genitals (in men).
In women, surgeons have successfully transplanted ovarian tissue from one woman to another since the mid-2000s, when an Alabama woman gave birth after getting a transplant from her identical twin sister. Last year, for the first time in the U.S., a young woman gave birth after getting a uterus transplant from a living donor.
"Where do you draw the line? Is pregnancy a privilege? Is it a right?"
As for men, surgeons in the U.S. and South Africa have successfully transplanted penises from dead men into four men whose genitals were injured by a botched circumcision, penile cancer or a wartime injury. One man reportedly fathered a child after the procedure.
The Johns Hopkins procedure was the first to include a scrotum. Testicles, however, were not transplanted due to ethical concerns. Surgeons have successfully transplanted testicles from man-to-man in the past, but this procedure isn't performed because the testes would produce sperm with the donor's DNA. As a result, the recipient could father a baby who is genetically related to the donor.
Are Transplants Worth the Expense and Risk?
Genital transplants are not simple procedures. They're extremely expensive, with a uterus transplant estimated to cost as much as $250,000. They're dangerous, since patients typically must take powerful drugs to keep their immune systems from rejecting their new organs. And they're not medically necessary. All have alternatives that are much less risky and costly.
Dr. Hiten D. Patel, a urologist at Johns Hopkins University, believes these types of factors make penis transplants unnecessary. As he wrote in a 2018 commentary in the journal European Urology, "What in the world are we doing?"
There are similar questions about female genital transplants, which allow infertile women to become pregnant instead of turning to alternatives like adoption or surrogacy. "This is not a life-saving transplant. A woman can very well live without a uterus," says McGill University's Dr. Jacques Balayla, who studies uterine transplantation. "Where do you draw the line? Is pregnancy a privilege? Is it a right? You don't want to cause harm to an individual unless there's an absolute need for the procedure."
But Johns Hopkins urologist Dr. Arthur L. Burnett II, who served on the surgical team that performed the penis-and-scrotum procedure, says penis transplants can be appropriate when other alternatives – like a "neophallus" created from forearm skin and tissue – aren't feasible.
It's also important to "restore normalcy," he says. "We want someone to be able to have sense of male adequacy and a normal sense of bodily well-being on both physical and psychological levels."
Surgical team members who performed the penis transplant, including W. P. Andrew Lee, director of the department of plastic and reconstructive surgery, center.
As for the anonymous recipient, he's reportedly doing "very well" five months after the transplant. An update on Johns Hopkins' website states that "he has normal urinary functions and is beginning to regain sensation in the transplanted tissues."
When the Organ Donors Do It Live
Some peculiar messages reached Burnett's desk after his institution announced it would begin performing penis transplants. Several men wanted to donate their own organs. But for now, transplanted penises are only coming from dead donors whose next of kin have approved the donation.
Burnett doesn't expect live donors to enter the penis transplant picture. But there are no guidelines or policies to stop surgeons from transplanting a penis from a live donor or, for that matter, a testicle.
Live women have already donated wombs and ovarian tissue, forcing them to face their own risks from transplant surgery. "You're putting the donor at risk because she has to undergo pretty expensive surgery for a procedure that is not technically lifesaving," McGill University's Balayla says.
When it comes to uterus transplants, the risk spreads even beyond donor and recipient. Balayla notes there's a third person in the equation: The fetus. "Immunosuppressant medication may harm the baby, and you're feeding the baby with a [uterine] blood vessel that's not natural, held together by stitches," he says.
It's up to each medical institution that performs the procedures to set its own policies.
Bioethicists are talking about other issues raised by genital transplants: How should operations for transgender people fit in? Should men be able to get penis transplants for purely cosmetic reasons? And then there's the looming question of genetic parenthood.
It's up to each medical institution that performs the procedures to set its own policies.
Let's say a woman gets a transplant of ovarian tissue, a man gets a testicle transplant, and they have a baby the old-fashioned way.* The child would be genetically linked to the donors, not the parents who conceived him or her.
Call this a full-employment act not just for bioethicists but theologians too. "Catholicism is generally against reproductive technologies because it removes God from the nature of the procreative act. This technology, though, could result in conception through the natural act. Would their concern remain?" DePaul University's Klugman asked. "Judaism is concerned with knowing a child's parentage, would a child from transplanted testes be the child of the donor or the recipient? Would an act of coitus with a transplanted penis be adultery?"
Yikes. Maybe it's time for the medical field or the law to step in to determine what genital transplants surgeons can and can't -- or shouldn't -- do.
So far, however, only uterus transplants have guidelines in place. Otherwise, it's up to each medical institution that performs the procedures to set its own policies.
"I don't know if the medical establishment is in the position to do the best job of self-regulation," says Lisa Campo-Engelstein, a bioethicist with Albany Medical College. "Reproductive medicine in this country is a huge for-profit industry. There's a possibility of exploitation if we leave this to for-profit fertility companies."
And, as bioethicist Klugman notes, guidelines "aren't laws, and people can and do violate them with no effect."
He doesn't think laws are the solution to the ethical issues raised by genital transplants either. Still, he says, "we do need a national conversation on these topics to help provide guidance for doctors and patients."
[Correction: The following sentence has been updated: "Let's say a woman gets a transplant of ovarian tissue, a man gets a testicle transplant, and they have a baby the old-fashioned way." The original sentence mistakenly read "uterus transplant" instead of "ovarian tissue."]
Silkworm silk is fragile, which limits its uses, but a few extra genes can help.
Today, biomimetics is everywhere. Shark-inspired swimming trunks, gecko-inspired adhesives, and lotus-inspired water-repellents are all taken from observing the natural world. After millions of years of evolution, nature has quite a few tricks up its sleeve. They are tricks we can learn from. And now, thanks to some spider DNA and clever genetic engineering, we have another one to add to the list.
The elusive spider silk
We’ve known for a long time that spider silk is remarkable, in ways that synthetic fibers can’t emulate. Nylon is incredibly strong (it can support a lot of force), and Kevlar is incredibly tough (it can absorb a lot of force). But neither is both strong and tough. In all artificial polymeric fibers, strength and toughness are mutually exclusive, and so we pick the material best for the job and make do.
Spider silk, a natural polymeric fiber, breaks this rule. It is somehow both strong and tough. No surprise, then, that spider silk is a source of much study.The problem, though, is that spiders are incredibly hard to cultivate — let alone farm. If you put them together, they will attack and kill each other until only one or a few survive. If you put 100 spiders in an enclosed space, they will go about an aggressive, arachnocidal Hunger Games. You need to give each its own space and boundaries, and a spider hotel is hard and costly. Silkworms, on the other hand, are peaceful and productive. They’ll hang around all day to make the silk that has been used in textiles for centuries. But silkworm silk is fragile. It has very limited use.
The elusive – and lucrative – trick, then, would be to genetically engineer a silkworm to produce spider-quality silk. So far, efforts have been fruitless. That is, until now.
We can have silkworms creating silk six times as tough as Kevlar and ten times as strong as nylon.
Spider-silkworms
Junpeng Mi and his colleagues working at Donghua University, China, used CRISPR gene-editing technology to recode the silk-creating properties of a silkworm. First, they took genes from Araneus ventricosus, an East Asian orb-weaving spider known for its strong silk. Then they placed these complex genes – genes that involve more than 100 amino acids – into silkworm egg cells. (This description fails to capture how time-consuming, technical, and laborious this was; it’s a procedure that requires hundreds of thousands of microinjections.)
This had all been done before, and this had failed before. Where Mi and his team succeeded was using a concept called “localization.” Localization involves narrowing in on a very specific location in a genome. For this experiment, the team from Donghua University developed a “minimal basic structure model” of silkworm silk, which guided the genetic modifications. They wanted to make sure they had the exactly right transgenic spider silk proteins. Mi said that combining localization with this basic structure model “represents a significant departure from previous research.” And, judging only from the results, he might be right. Their “fibers exhibited impressive tensile strength (1,299 MPa) and toughness (319 MJ/m3), surpassing Kevlar’s toughness 6-fold.”
A world of super-materials
Mi’s research represents the bursting of a barrier. It opens up hugely important avenues for future biomimetic materials. As Mi puts it, “This groundbreaking achievement effectively resolves the scientific, technical, and engineering challenges that have hindered the commercialization of spider silk, positioning it as a viable alternative to commercially synthesized fibers like nylon and contributing to the advancement of ecological civilization.”
Around 60 percent of our clothing is made from synthetic fibers like nylon, polyester, and acrylic. These plastics are useful, but often bad for the environment. They shed into our waterways and sometimes damage wildlife. The production of these fibers is a source of greenhouse gas emissions. Now, we have a “sustainable, eco-friendly high-strength and ultra-tough alternative.” We can have silkworms creating silk six times as tough as Kevlar and ten times as strong as nylon.
We shouldn’t get carried away. This isn’t going to transform the textiles industry overnight. Gene-edited silkworms are still only going to produce a comparatively small amount of silk – even if farmed in the millions. But, as Mi himself concedes, this is only the beginning. If Mi’s localization and structure-model techniques are as remarkable as they seem, then this opens up the door to a great many supermaterials.
Nature continues to inspire. We had the bird, the gecko, and the shark. Now we have the spider-silkworm. What new secrets will we unravel in the future? And in what exciting ways will it change the world?
This article originally appeared on Freethink, home of the brightest minds and biggest ideas of all time.
