Junjiu Huang and his team performed a miracle. A few miracles, actually. The researchers at Sun Yat-sen University in Guangzhou, China used the precise new DNA editing tool called CRISPR-CAS9 to edit a human embryo, replacing a single base. In doing so, they edited out beta-thalassemia, a blood disorder that reduces the production of hemoglobin, which can result in pale skin, fatigue, higher risk of blood clots, and other symptoms.
The race is on, and it's one everyone is going to try to win.
Huang's group, which did not respond to an email requesting comment for this story, injected 86 embryos and observed them for 48 hours. After that period -- a time long enough for CRISPR to split the DNA, other molecules to replace the base, and the embryos to grow to eight cells -- they tested 54 of the 71 that survived. Of those, only a few had the replacement base, according to a report of the study published in Protein & Cell. The experiment stopped there as the embryos, which had been acquired from local fertility clinics, were non-viable and not implanted.
But procreation was not the point. Far from it, in fact. The point was to demonstrate that it could be done, that in some far off (or not so far off) future, doctors could use CRISPR to eliminate diseases like Tay-Sachs, Huntington's, and cystic fibrosis that are caused by genetic mutations. Going a step further, perhaps they could eventually even tailor embryos that will develop into adults with specific traits like height and IQ.
Experts agree that we are far from that point, years if not decades away from leveraging CRISPR to cure diseases and decades if not centuries from being able to build designer babies. In that frame, Huang's achievement is just a small step, a blip on the timeline of human achievement. But seen in another light, it's yet another sign that we need to start talking about DNA modification now, establishing protocols, procedures, and plans that guide the subject before we get so far down the road that momentum is impossible to stop.
"The Chinese generally don't have the religious objections to embryo research that have held back research in the West."
It's essential to do so now because the idea of DNA modification -- a realization that humanity can control its evolution -- is compelling and attractive. Imagine a world where doctors and scientists could get rid of disease before it begins or ensure a baby would arrive with an Einstein-level IQ. That's intriguing, and also terrifying. What are the rules? How do we know when to stop? What guides the process? And how can we prevent mistakes or unwanted mutations? To borrow from another famous quotation, with great power comes great responsibility.
These aren't questions for Huang and the Chinese scientific community alone. A team from Oregon recently edited viable human embryos, eliminating a mutation that can lead to heart failure while preventing any unintended consequences. Just as importantly, every embryo they edited produced the intended genetic changes, a vital step since a partial success rate, known as mosaicism, could have devastating consequences to a future child.
In London at the Francis Crick Institute, researcher Kathy Niakan used CRISPR-CAS9 to "turn off" a gene that produces the protein OCT4. Without the protein, the fertilized egg could not produce a blastocyst, which is a key structure in early mammalian development that gives rise to an embryo and placenta. The recent study wasn't designed to go further, but the use of CRISPR was important. "One way to find out what a gene does in the developing embryo is to see what happens when it isn't working," said Dr. Niakan, who was the first scientist in the world to be granted regulatory approval to edit the genes of a human embryo for research. "Now that we have demonstrated an efficient way of doing this, we hope that other scientists will use it to find out the roles of other genes. If we knew the key genes that embryos need to develop successfully, we could improve IVF treatments and understand some causes of pregnancy failure. It may take many years to achieve such an understanding. Our study is just the first step."
The point is, CRISPR is here and it's not going anywhere. Scientists will continue to use it to learn about how humans develop. Yet different rules regarding CRISPR and embryo research in countries around the world will impact who gets there first. "I've heard the U.S.-China gene editing research parallel paths as Sputnik 2.0," said Kevin Doxzen, Science Communications Specialist at the University of California, Berkeley's Innovative Genomics Institute. The race is on, and it's one everyone is going to try to win.
Based on number of researchers and ease of regulations, the Chinese are the favorites to advance the science the furthest, the fastest.
Based on number of researchers and ease of regulations, the Chinese are the favorites to advance the science the furthest, the fastest. "The Chinese generally don't have the religious (predominantly Christian) or moral objections to embryo research that have held back research in the West," said Dr. Julian Savulescu, the Uehiro Professor of Practical Ethics and Director of the Oxford Martin Programme on Collective Responsibility for Infectious Disease at the University of Oxford. "This kind of research should be done, with the right sort of ethical oversight. The concern over China leading the way is that institutional oversight mechanisms are probably not as developed as in the West but so far, there is no evidence of breaches in standards of research ethics around the published research."
Or, put another way by bioethicist Dr. Arthur Caplan, founding director of NYU Langone Health's Division of Medical Ethics: "The Chinese, because they don't care and don't have moral reservations about embryo work, are doing what they want." This lack of aversion to working with embryos manifests itself in a couple of ways. The absence of moral qualms is one. Funding is another. Huang's study, and others like it, receive funding from the government. His, for example, was supported by two grants from the National Basic Research Program and three from the National Natural Science Foundation of China.
The U.S., on the other hand, bans any federal funding for research using human embryos. A law passed in 1996 states that federal dollars can't be used for: "research in which a human embryo or embryos are destroyed, discarded, or knowingly subjected to risk of injury or death greater than that allowed for research on fetuses." This restriction can shift incentives as many private institutions or commercial enterprises may have financial motivations or other goals beyond furthering basic research for the sake of general knowledge.
Embryo gene modification recently performed in the U.K. would merit 15 years in prison in Australia.
The embryo research ban is even more strict elsewhere. The Oviedo Convention, enacted in 1997, effectively prohibits germline engineering in members of the European Union. "In Italy, you can't destroy an embryo for any reason," said Alessandro Bertero, a postdoctoral fellow at the University of Washington's Department of Pathology who used to study in Italy. "It's illegal, and you'll go to jail." Later, Bertero was one of the researchers who worked with Dr. Niakan in London, an investigation that was allowed by the UK's Human Fertilisation and Embryology Authority. (In Australia, Niakan and her colleagues would face 15 years in jail due to the 2002 Prohibition of Human Cloning Act, which prohibits altering the genomes of embryonic cells.)
Despite the moral and legal reservations in the Western world, every person I spoke with for this story believed that better, more advanced studies and learning is happening in the U.S. and Europe. "The best studies in my opinion are from the labs in California and Oregon," Bertero said. "The quality of the work [in the Chinese study] – not being critical, but to be scientifically critical -- was just quick and dirty. It was, 'Let's just show that we have done it and get it out.' That doesn't mean that the quality of the work was good."
"If the Chinese or someone else starts beating our brains out, we're not going to want to stand by idly and not do these things."
How long that remains the case, however, is an open question. A significant number of groups in China are working on germline editing in human embryos. The concern is that the Chinese will emerge as a leader sooner rather than later because they can do research with embryos more easily than their Western counterparts.
For Caplan, the NYU professor, the embryo ban in the U.S. isn't based on science; it's rooted in something else. "It's 96 percent political," he said, laughing. "It has basically ground to a halt because no one wants to see repercussions take place if federal funding is involved. The NIH isn't involved. And they won't be."
What, in his mind, would get Americans to start realizing the benefits that embryo research would provide? "The perception that other countries were moving quickly to get the advantages of CRISPR and other gene modification techniques, finding more industrial and more medical purposes," he said. "If the Chinese or someone else starts beating our brains out, we're not going to want to stand by idly and not do these things."
Doing so would involve difficult conversations about the role of embryos in research. But these are philosophical questions that need to be approached at some point. From a U.S. perspective, doing so sooner while the American scientists still hold the technological and informational edge, is vital. Ignoring the issue doesn't make it go away.
Experts think a few changes should be made. The ban on federal funding should be lifted. Scientists and regulators should push for things like allowing federal funds to be used for the creation of new embryos for research purposes and the use of spare IVF embryos for research when the embryo would not be implanted into a woman. (Privately funded scientists can proceed in states that encourage embryonic stem cell research, like New York, New Jersey, and California, but not in restrictive ones like Louisiana and South Dakota, which prohibit creating or destroying embryos for research.) Policymakers could ban reproductive gene editing for now but look at it again after a certain period. A highly anticipated report issued earlier this year from an international guidance committee left the door open to eventual clinical trials with edited embryos. As of now, however, Congress will not allow the Food and Drug Administration to consider such trials. This is the future and it's the scientific community's responsibility to develop the ethical framework now.
"The US and Europe have the technological history and capacity to lead this research and should do so, ethically. We ought to be revising our laws and ethical guidelines to facilitate this kind of research," Professor Savulescu said. "But the challenge is to think constructively and ethically about this new technology, and to be leaders, not followers."
In December 1958, on a vacation with his wife in Kenya, a 28-year-old British tea broker named Robin Cavendish became suddenly ill. Neither he nor his wife Diana knew it at the time, but Robin's illness would change the course of medical history forever.
Robin was rushed to a nearby hospital in Kenya where the medical staff delivered the crushing news: Robin had contracted polio, and the paralysis creeping up his body was almost certainly permanent. The doctors placed Robin on a ventilator through a tracheotomy in his neck, as the paralysis from his polio infection had rendered him unable to breathe on his own – and going off the average life expectancy at the time, they gave him only three months to live. Robin and Diana (who was pregnant at the time with their first child, Jonathan) flew back to England so he could be admitted to a hospital. They mentally prepared to wait out Robin's final days.
But Robin did something unexpected when he returned to the UK – just one of many things that would astonish doctors over the next several years: He survived. Diana gave birth to Jonathan in February 1959 and continued to visit Robin regularly in the hospital with the baby. Despite doctors warning that he would soon succumb to his illness, Robin kept living.
After a year in the hospital, Diana suggested something radical: She wanted Robin to leave the hospital and live at home in South Oxfordshire for as long as he possibly could, with her as his nurse. At the time, this suggestion was unheard of. People like Robin who depended on machinery to keep them breathing had only ever lived inside hospital walls, as the prevailing belief was that the machinery needed to keep them alive was too complicated for laypeople to operate. But Diana and Robin were up for the challenges – and the risks. Because his ventilator ran on electricity, if the house were to unexpectedly lose power, Diana would either need to restore power quickly or hand-pump air into his lungs to keep him alive.
Robin's wheelchair was not only the first of its kind; it became the model for the respiratory wheelchairs that people still use today.
In an interview as an adult, Jonathan Cavendish reflected on his parents' decision to live outside the hospital on a ventilator: "My father's mantra was quality of life," he explained. "He could have stayed in the hospital, but he didn't think that was as good of a life as he could manage. He would rather be two minutes away from death and living a full life."
After a few years of living at home, however, Robin became tired of being confined to his bed. He longed to sit outside, to visit friends, to travel – but had no way of doing so without his ventilator. So together with his friend Teddy Hall, a professor and engineer at Oxford University, the two collaborated in 1962 to create an entirely new invention: a battery-operated wheelchair prototype with a ventilator built in. With this, Robin could now venture outside the house – and soon the Cavendish family became famous for taking vacations. It was something that, by all accounts, had never been done before by someone who was ventilator-dependent. Robin and Hall also designed a van so that the wheelchair could be plugged in and powered during travel. Jonathan Cavendish later recalled a particular family vacation that nearly ended in disaster when the van broke down outside of Barcelona, Spain:
"My poor old uncle [plugged] my father's chair into the wrong socket," Cavendish later recalled, causing the electricity to short. "There was fire and smoke, and both the van and the chair ground to a halt." Johnathan, who was eight or nine at the time, his mother, and his uncle took turns hand-pumping Robin's ventilator by the roadside for the next thirty-six hours, waiting for Professor Hall to arrive in town and repair the van. Rather than being panicked, the Cavendishes managed to turn the vigil into a party. Townspeople came to greet them, bringing food and music, and a local priest even stopped by to give his blessing.
Robin had become a pioneer, showing the world that a person with severe disabilities could still have mobility, access, and a fuller quality of life than anyone had imagined. His mission, along with Hall's, then became gifting this independence to others like himself. Robin and Hall raised money – first from the Ernest Kleinwort Charitable Trust, and then from the British Department of Health – to fund more ventilator chairs, which were then manufactured by Hall's company, Littlemore Scientific Engineering, and given to fellow patients who wanted to live full lives at home. Robin and Hall used themselves as guinea pigs, testing out different models of the chairs and collaborating with scientists to create other devices for those with disabilities. One invention, called the Possum, allowed paraplegics to control things like the telephone and television set with just a nod of the head. Robin's wheelchair was not only the first of its kind; it became the model for the respiratory wheelchairs that people still use today.
Robin went on to enjoy a long and happy life with his family at their house in South Oxfordshire, surrounded by friends who would later attest to his "down-to-earth" personality, his sense of humor, and his "irresistible" charm. When he died peacefully at his home in 1994 at age 64, he was considered the world's oldest-living person who used a ventilator outside the hospital – breaking yet another barrier for what medical science thought was possible.
Sarah Watts is a health and science writer based in Chicago. Follow her on Twitter at @swattswrites.
In June 2012, Kirstie Ennis was six months into her second deployment to Afghanistan and recently promoted to sergeant. The helicopter gunner and seven others were three hours into a routine mission of combat resupplies and troop transport when their CH-53D helicopter went down hard.
Miraculously, all eight people onboard survived, but Ennis' injuries were many and severe. She had a torn rotator cuff, torn labrum, crushed cervical discs, facial fractures, deep lacerations and traumatic brain injury. Despite a severely fractured ankle, doctors managed to save her foot, for a while at least.
In November 2015, after three years of constant pain and too many surgeries to count, Ennis relented. She elected to undergo a lower leg amputation but only after she completed the 1,000-mile, 72-day Walking with the Wounded journey across the UK.
On Veteran's Day of that year, on the other side of the country, orthopedic surgeon Cato Laurencin announced a moonshot challenge he was setting out to achieve on behalf of wounded warriors like Ennis: the Hartford Engineering A Limb (HEAL) Project.
Laurencin, who is a University of Connecticut professor of chemical, materials and biomedical engineering, teamed up with experts in tissue bioengineering and regenerative medicine from Harvard, Columbia, UC Irvine and SASTRA University in India. Laurencin and his colleagues at the Connecticut Convergence Institute for Translation in Regenerative Engineering made a bold commitment to regenerate an entire limb within 15 years – by the year 2030.
Dr. Cato Laurencin pictured in his office at UConn.
Photo Credit: UConn
Regenerative Engineering -- A Whole New Field
Limb regeneration in humans has been a medical and scientific fascination for decades, with little to show for the effort. However, Laurencin believes that if we are to reach the next level of 21st century medical advances, this puzzle must be solved.
An estimated 185,000 people undergo upper or lower limb amputation every year. Despite the significant advances in electromechanical prosthetics, these individuals still lack the ability to perform complex functions such as sensation for tactile input, normal gait and movement feedback. As far as Laurencin is concerned, the only clinical answer that makes sense is to regenerate a whole functional limb.
Laurencin feels other regeneration efforts were hampered by their siloed research methods with chemists, surgeons, engineers all working separately. Success, he argues, requires a paradigm shift to a trans-disciplinary approach that brings together cutting-edge technologies from disparate fields such as biology, material sciences, physical, chemical and engineering sciences.
As the only surgeon ever inducted into the academies of Science, Medicine and Innovation, Laurencin is uniquely suited for the challenge. He is regarded as the founder of Regenerative Engineering, defined as the convergence of advanced materials sciences, stem cell sciences, physics, developmental biology and clinical translation for the regeneration of complex tissues and organ systems.
But none of this is achievable without early clinician participation across scientific fields to develop new technologies and a deeper understanding of how to harness the body's innate regenerative capabilities. "When I perform a surgical procedure or something is torn or needs to be repaired, I count on the body being involved in regenerating tissue," he says. "So, understanding how the body works to regenerate itself and harnessing that ability is an important factor for the regeneration process."
The Birth of the Vision
Laurencin's passion for regeneration began when he was a sports medicine fellow at Cornell University Medical Center in the early 1990s. There he saw a significant number of injuries to the anterior cruciate ligament (ACL), the major ligament that stabilizes the knee. He believed he could develop a better way to address those injuries using biomaterials to regenerate the ligament. He sketched out a preliminary drawing on a napkin one night over dinner. He has spent the next 30 years regenerating tissues, including the patented L-C ligament.
As chair of Orthopaedic Surgery at the University of Virginia during the peak of the wars in Iraq and Afghanistan, Laurencin treated military personnel who survived because of improved helmets, body armor and battlefield medicine but were left with more devastating injuries, including traumatic brain injuries and limb loss.
"I was so honored to care for them and I so admired their steadfast courage that I became determined to do something big for them," says Laurencin.
When he tells people about his plans to regrow a limb, he gets a lot of eye rolls, which he finds amusing but not discouraging. Growing bone cells was relatively new when he was first focused on regenerating bone in 1987 at MIT; in 2007 he was well on his way to regenerating ligaments at UVA when many still doubted that ligaments could even be reconstructed. He and his team have already regenerated torn rotator cuff tendons and ACL ligaments using a nano-textured fabric seeded with stem cells.
Even as a finalist for the $4 million NIH Pioneer Award for high-risk/high-reward research, he faced a skeptical scientific audience in 2014. "They said, 'Well what do you plan to do?' I said 'I plan to regenerate a whole limb in people.' There was a lot of incredulousness. They stared at me and asked a lot of questions. About three days later, I received probably the best score I've ever gotten on an NIH grant."
In the Thick of the Science
Humans are born with regenerative abilities--two-year-olds have regrown fingertips--but lose that ability with age. Salamanders are the only vertebrates that can regenerate lost body parts as adults; axolotl, the rare Mexican salamander, can grow extra limbs.
The axolotl is important as a model organism because it is a four-footed vertebrate with a similar body plan to humans. Mapping the axolotl genome in 2018 enhanced scientists' genetic understanding of their evolution, development, and regeneration. Being easy to breed in captivity allowed the HEAL team to closely study these amphibians and discover a new cell type they believe may shed light on how to mimic the process in humans.
"Whenever limb regeneration takes place in the salamander, there is a huge amount of something called heparan sulfate around that area," explains Laurencin. "We thought, 'What if this heparan sulfate is the key ingredient to allowing regeneration to take place?' We found these groups of cells that were interspersed in tissues during the time of regeneration that seemed to have connections to each other that expressed this heparan sulfate."
Called GRID (Groups that are Regenerative, Interspersed and Dendritic), these cells were also recently discovered in mice. While GRID cells don't regenerate as well in mice as in salamanders, finding them in mammals was significant.
"If they're found in mice. we might be able to find these in humans in some form," Laurencin says. "We think maybe it will help us figure out regeneration or we can create cells that mimic what grid cells do and create an artificial grid cell."
What Comes Next?
Laurencin and his team have individually engineered and made every single tissue in the lower limb, including bone, cartilage, ligament, skin, nerve, blood vessels. Regenerating joints and joint tissue is the next big mile marker, which Laurencin sees as essential to regenerating a limb that functions and performs in the way he envisions.
"Using stem cells and amnion tissue, we can regenerate joints that are damaged, and have severe arthritis," he says. "We're making progress on all fronts, and making discoveries we believe are going to be helping people along the way."
That focus and advancement is vital to Ennis. After laboring over the decision to have her leg amputated below the knee, she contracted MRSA two weeks post-surgery. In less than a month, she went from a below-the-knee-amputee to a through-the-knee amputee to an above-the-knee amputee.
"A below-the-knee amputation is night-and-day from above-the-knee," she said. "You have to relearn everything. You're basically a toddler."
Kirstie Ennis pictured in July 2020.
Photo Credit: Ennis' Instagram
The clock is ticking on the timeline Laurencin set for himself. Nine years might seem like forever if you're doing time but it might appear fleeting when you're trying to create something that's never been done before. But Laurencin isn't worried. He's convinced time is on his side.
"Every week, I receive an email or a call from someone, maybe a mother whose child has lost a finger or I'm in communication with a disabled American veteran who wants to know how the progress is going. That energizes me to continue to work hard to try to create these sorts of solutions because we're talking about people and their lives."
He devotes about 60 hours a week to the project and the roughly 100 students, faculty and staff who make up the HEAL team at the Convergence Institute seem acutely aware of what's at stake and appear equally dedicated.
"We're in the thick of the science in terms of making this happen," says Laurencin. "We've moved from making the impossible possible to making the possible a reality. That's what science is all about."