Where Are the Lab-Grown Replacement Organs?
A futuristic rendering of a scientist holding a pair of lungs in a glass dish.
The headline blared from newspapers all the way back in 2006: "First Lab-Grown Organs Implanted in Humans!" A team from Wake Forest University had biopsied cells from the bladders of patients with spina bifida and used them to create brand new full-size bladders, which they then implanted. Although the bladders had to be emptied via catheter, they were still functioning a few years after implantation, and the public grew confident that doctors had climbed an intermediary step on the way to the medicine of science fiction. Ten years later, though, more than 20 people a day are still dying while waiting for an organ transplant, which leads to a simple question: Where are our fake organs?
"We can make small organs and tissues but we can't make larger ones."
Not coming anytime soon, unfortunately. The company that was created to transition Wake Forest's bladders to the market failed. And while there are a few simple bioengineered skins and cartilages already on the market, they are hardly identical to the real thing. Something like a liver could take another 20 to 25 years, says Shay Soker, professor at Wake Forest's Institute for Regenerative Medicine. "The first barrier is the technology: We can make small organs and tissues but we can't make larger ones," he says. "Also there are several cell types or functions that you can reliably make from stem cells, but not all of them, so the technology of stem cells has to catch up with what the body can do." Finally, he says, you have support the new organ inside the body, providing it with a circulatory and nervous system and integrating it with the immune system.
While these are all challenging problems, circulation appears to be the most intractable. "Tissue's not able to survive if the cells don't have oxygen, and the bigger it gets, the more complex vasculature you need to keep that alive," says Chiara Ghezzi, research professor in the Tufts University Department of Biomedical Engineering. "Vasculature is highly organized in the body. It has a hierarchical structure, with different branches that have different roles depending on where they are." So far, she says, researchers have had trouble scaling up from capillaries to larger vessels that could be grafted onto blood vessels in a patient's body.
"The FDA is still getting its hands and minds around the field of tissue engineering."
Last, but hardly least, is the question of FDA approval. Lab-grown organs are neither drugs nor medical devices, and the agency is not set up to quickly or easily approve new technologies that don't fit into current categories. "The FDA is still getting its hands and minds around the field of tissue engineering," says Soker. "They were not used to that… so it requires the regulatory and financial federal agencies to really help and support these initiatives."
A pencil eraser-size model of the human brain is now being used for drug development and research.
If all of this sounds discouraging, it's worth mentioning some of the incredible progress the field has made since the first strides toward lab-grown organs began nearly 30 years ago: Though full-size replacement organs are still decades away, many labs have diverted their resources into what they consider an intermediate step, developing miniature organs and systems that can be used for drug development and research. This platform will yield more relevant results (Imagine! Testing cardiovascular drugs on an actual human heart!) and require the deaths of far fewer animals. And it's already here: Two years ago, scientists at Ohio State University developed a pencil eraser-size model of the human brain they intend to use for this exact purpose.
Perhaps the most exciting line of research these days is one that at first doesn't seem to have anything to do with bioengineered organs at all. Along with his colleagues, Chandan Sen, Director of the Center for Regenerative Medicine and Cell-based Therapies at Ohio State University, has developed a nanoscale chip that can turn any cell in the body into any other kind of cell—reverting fully differentiated adult cells into, essentially, stem cells, which can then grow into any tissue you want. Sen has used his chip to reprogram skin cells in the bodies of mice into neurons to help them recover from strokes, and blood vessels to save severe leg injuries. "There's this concept of a bioreactor, where you convince an organ to grow outside the body. They're getting more and more sophisticated over time. But to my mind it will never match the sophistication or complexity of the human body," Sen says. "I believe that in order to have an organ that behaves the way you want it to in the live body, you must use the body itself as a bioreactor, not a bunch of electronic gadgetry." There you have it, the next step in artificial organ manufacture is as crazy as it is intuitive: Grow it back where it was in the first place.
Urinary tract infections account for more than 8 million trips to the doctor each year.
Few things are more painful than a urinary tract infection (UTI). Common in men and women, these infections account for more than 8 million trips to the doctor each year and can cause an array of uncomfortable symptoms, from a burning feeling during urination to fever, vomiting, and chills. For an unlucky few, UTIs can be chronic—meaning that, despite treatment, they just keep coming back.
But new research, presented at the European Association of Urology (EAU) Congress in Paris this week, brings some hope to people who suffer from UTIs.
Clinicians from the Royal Berkshire Hospital presented the results of a long-term, nine-year clinical trial where 89 men and women who suffered from recurrent UTIs were given an oral vaccine called MV140, designed to prevent the infections. Every day for three months, the participants were given two sprays of the vaccine (flavored to taste like pineapple) and then followed over the course of nine years. Clinicians analyzed medical records and asked the study participants about symptoms to check whether any experienced UTIs or had any adverse reactions from taking the vaccine.
The results showed that across nine years, 48 of the participants (about 54%) remained completely infection-free. On average, the study participants remained infection free for 54.7 months—four and a half years.
“While we need to be pragmatic, this vaccine is a potential breakthrough in preventing UTIs and could offer a safe and effective alternative to conventional treatments,” said Gernot Bonita, Professor of Urology at the Alta Bro Medical Centre for Urology in Switzerland, who is also the EAU Chairman of Guidelines on Urological Infections.
The news comes as a relief not only for people who suffer chronic UTIs, but also to doctors who have seen an uptick in antibiotic-resistant UTIs in the past several years. Because UTIs usually require antibiotics, patients run the risk of developing a resistance to the antibiotics, making infections more difficult to treat. A preventative vaccine could mean less infections, less antibiotics, and less drug resistance overall.
“Many of our participants told us that having the vaccine restored their quality of life,” said Dr. Bob Yang, Consultant Urologist at the Royal Berkshire NHS Foundation Trust, who helped lead the research. “While we’re yet to look at the effect of this vaccine in different patient groups, this follow-up data suggests it could be a game-changer for UTI prevention if it’s offered widely, reducing the need for antibiotic treatments.”
MILESTONE: Doctors have transplanted a pig organ into a human for the first time in history
A surgeon at Massachusetts General Hospital prepares a pig organ for transplant.
Surgeons at Massachusetts General Hospital made history last week when they successfully transplanted a pig kidney into a human patient for the first time ever.
The recipient was a 62-year-old man named Richard Slayman who had been living with end-stage kidney disease caused by diabetes. While Slayman had received a kidney transplant in 2018 from a human donor, his diabetes ultimately caused the kidney to fail less than five years after the transplant. Slayman had undergone dialysis ever since—a procedure that uses an artificial kidney to remove waste products from a person’s blood when the kidneys are unable to—but the dialysis frequently caused blood clots and other complications that landed him in the hospital multiple times.
As a last resort, Slayman’s kidney specialist suggested a transplant using a pig kidney provided by eGenesis, a pharmaceutical company based in Cambridge, Mass. The highly experimental surgery was made possible with the Food and Drug Administration’s “compassionate use” initiative, which allows patients with life-threatening medical conditions access to experimental treatments.
The new frontier of organ donation
Like Slayman, more than 100,000 people are currently on the national organ transplant waiting list, and roughly 17 people die every day waiting for an available organ. To make up for the shortage of human organs, scientists have been experimenting for the past several decades with using organs from animals such as pigs—a new field of medicine known as xenotransplantation. But putting an animal organ into a human body is much more complicated than it might appear, experts say.
“The human immune system reacts incredibly violently to a pig organ, much more so than a human organ,” said Dr. Joren Madsen, director of the Mass General Transplant Center. Even with immunosuppressant drugs that suppress the body’s ability to reject the transplant organ, Madsen said, a human body would reject an animal organ “within minutes.”
So scientists have had to use gene-editing technology to change the animal organs so that they would work inside a human body. The pig kidney in Slayman’s surgery, for instance, had been genetically altered using CRISPR-Cas9 technology to remove harmful pig genes and add human ones. The kidney was also edited to remove pig viruses that could potentially infect a human after transplant.
With CRISPR technology, scientists have been able to prove that interspecies organ transplants are not only possible, but may be able to successfully work long term, too. In the past several years, scientists were able to transplant a pig kidney into a monkey and have the monkey survive for more than two years. More recently, doctors have transplanted pig hearts into human beings—though each recipient of a pig heart only managed to live a couple of months after the transplant. In one of the patients, researchers noted evidence of a pig virus in the man’s heart that had not been identified before the surgery and could be a possible explanation for his heart failure.
So far, so good
Slayman and his medical team ultimately decided to pursue the surgery—and the risk paid off. When the pig organ started producing urine at the end of the four-hour surgery, the entire operating room erupted in applause.
Slayman is currently receiving an infusion of immunosuppressant drugs to prevent the kidney from being rejected, while his doctors monitor the kidney’s function with frequent ultrasounds. Slayman is reported to be “recovering well” at Massachusetts General Hospital and is expected to be discharged within the next several days.