Where Are the Lab-Grown Replacement Organs?
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.
This man spent over 70 years in an iron lung. What he was able to accomplish is amazing.
It’s a sight we don’t normally see these days: A man lying prone in a big, metal tube with his head sticking out of one end. But it wasn’t so long ago that this sight was unfortunately much more common.
In the first half of the 20th century, tens of thousands of people each year were infected by polio—a highly contagious virus that attacks nerves in the spinal cord and brainstem. Many people survived polio, but a small percentage of people who did were left permanently paralyzed from the virus, requiring support to help them breathe. This support, known as an “iron lung,” manually pulled oxygen in and out of a person’s lungs by changing the pressure inside the machine.
Paul Alexander was one of several thousand who were infected and paralyzed by polio in 1952. That year, a polio epidemic swept the United States, forcing businesses to close and polio wards in hospitals all over the country to fill up with sick children. When Paul caught polio in the summer of 1952, doctors urged his parents to let him rest and recover at home, since the hospital in his home suburb of Dallas, Texas was already overrun with polio patients.
Paul rested in bed for a few days with aching limbs and a fever. But his condition quickly got worse. Within a week, Paul could no longer speak or swallow, and his parents rushed him to the local hospital where the doctors performed an emergency procedure to help him breathe. Paul woke from the surgery three days later, and found himself unable to move and lying inside an iron lung in the polio ward, surrounded by rows of other paralyzed children.
Hospitals were commonly filled with polio patients who had been paralyzed by the virus before a vaccine became widely available in 1955. Associated Press
Paul struggled inside the polio ward for the next 18 months, bored and restless and needing to hold his breath when the nurses opened the iron lung to help him bathe. The doctors on the ward frequently told his parents that Paul was going to die.But against all odds, Paul lived. And with help from a physical therapist, Paul was able to thrive—sometimes for small periods outside the iron lung.
The way Paul did this was to practice glossopharyngeal breathing (or as Paul called it, “frog breathing”), where he would trap air in his mouth and force it down his throat and into his lungs by flattening his tongue. This breathing technique, taught to him by his physical therapist, would allow Paul to leave the iron lung for increasing periods of time.
With help from his iron lung (and for small periods of time without it), Paul managed to live a full, happy, and sometimes record-breaking life. At 21, Paul became the first person in Dallas, Texas to graduate high school without attending class in person, owing his success to memorization rather than taking notes. After high school, Paul received a scholarship to Southern Methodist University and pursued his dream of becoming a trial lawyer and successfully represented clients in court.
Paul Alexander, pictured here in his early 20s, mastered a type of breathing technique that allowed him to spend short amounts of time outside his iron lung. Paul Alexander
Paul practiced law in North Texas for more than 30 years, using a modified wheelchair that held his body upright. During his career, Paul even represented members of the biker gang Hells Angels—and became so close with them he was named an honorary member.Throughout his long life, Paul was also able to fly on a plane, visit the beach, adopt a dog, fall in love, and write a memoir using a plastic stick to tap out a draft on a keyboard. In recent years, Paul joined TikTok and became a viral sensation with more than 330,000 followers. In one of his first videos, Paul advocated for vaccination and warned against another polio epidemic.
Paul was reportedly hospitalized with COVID-19 at the end of February and died on March 11th, 2024. He currently holds the Guiness World Record for longest survival inside an iron lung—71 years.
Polio thankfully no longer circulates in the United States, or in most of the world, thanks to vaccines. But Paul continues to serve as a reminder of the importance of vaccination—and the power of the human spirit.
““I’ve got some big dreams. I’m not going to accept from anybody their limitations,” he said in a 2022 interview with CNN. “My life is incredible.”
When doctors couldn’t stop her daughter’s seizures, this mom earned a PhD and found a treatment herself.
Twenty-eight years ago, Tracy Dixon-Salazaar woke to the sound of her daughter, two-year-old Savannah, in the midst of a medical emergency.
“I entered [Savannah’s room] to see her tiny little body jerking about violently in her bed,” Tracy said in an interview. “I thought she was choking.” When she and her husband frantically called 911, the paramedic told them it was likely that Savannah had had a seizure—a term neither Tracy nor her husband had ever heard before.
Over the next several years, Savannah’s seizures continued and worsened. By age five Savannah was having seizures dozens of times each day, and her parents noticed significant developmental delays. Savannah was unable to use the restroom and functioned more like a toddler than a five-year-old.
Doctors were mystified: Tracy and her husband had no family history of seizures, and there was no event—such as an injury or infection—that could have caused them. Doctors were also confused as to why Savannah’s seizures were happening so frequently despite trying different seizure medications.
Doctors eventually diagnosed Savannah with Lennox-Gaustaut Syndrome, or LGS, an epilepsy disorder with no cure and a poor prognosis. People with LGS are often resistant to several kinds of anti-seizure medications, and often suffer from developmental delays and behavioral problems. People with LGS also have a higher chance of injury as well as a higher chance of sudden unexpected death (SUDEP) due to the frequent seizures. In about 70 percent of cases, LGS has an identifiable cause such as a brain injury or genetic syndrome. In about 30 percent of cases, however, the cause is unknown.
Watching her daughter struggle through repeated seizures was devastating to Tracy and the rest of the family.
“This disease, it comes into your life. It’s uninvited. It’s unannounced and it takes over every aspect of your daily life,” said Tracy in an interview with Today.com. “Plus it’s attacking the thing that is most precious to you—your kid.”
Desperate to find some answers, Tracy began combing the medical literature for information about epilepsy and LGS. She enrolled in college courses to better understand the papers she was reading.
“Ironically, I thought I needed to go to college to take English classes to understand these papers—but soon learned it wasn’t English classes I needed, It was science,” Tracy said. When she took her first college science course, Tracy says, she “fell in love with the subject.”
Tracy was now a caregiver to Savannah, who continued to have hundreds of seizures a month, as well as a full-time student, studying late into the night and while her kids were at school, using classwork as “an outlet for the pain.”
“I couldn’t help my daughter,” Tracy said. “Studying was something I could do.”
Twelve years later, Tracy had earned a PhD in neurobiology.
After her post-doctoral training, Tracy started working at a lab that explored the genetics of epilepsy. Savannah’s doctors hadn’t found a genetic cause for her seizures, so Tracy decided to sequence her genome again to check for other abnormalities—and what she found was life-changing.
Tracy discovered that Savannah had a calcium channel mutation, meaning that too much calcium was passing through Savannah’s neural pathways, leading to seizures. The information made sense to Tracy: Anti-seizure medications often leech calcium from a person’s bones. When doctors had prescribed Savannah calcium supplements in the past to counteract these effects, her seizures had gotten worse every time she took the medication. Tracy took her discovery to Savannah’s doctor, who agreed to prescribe her a calcium blocker.
The change in Savannah was almost immediate.
Within two weeks, Savannah’s seizures had decreased by 95 percent. Once on a daily seven-drug regimen, she was soon weaned to just four, and then three. Amazingly, Tracy started to notice changes in Savannah’s personality and development, too.
“She just exploded in her personality and her talking and her walking and her potty training and oh my gosh she is just so sassy,” Tracy said in an interview.
Since starting the calcium blocker eleven years ago, Savannah has continued to make enormous strides. Though still unable to read or write, Savannah enjoys puzzles and social media. She’s “obsessed” with boys, says Tracy. And while Tracy suspects she’ll never be able to live independently, she and her daughter can now share more “normal” moments—something she never anticipated at the start of Savannah’s journey with LGS. While preparing for an event, Savannah helped Tracy get ready.
“We picked out a dress and it was the first time in our lives that we did something normal as a mother and a daughter,” she said. “It was pretty cool.”