BUILDING BODY PARTS
Scientists work toward growing complex organs such as hearts and lungs.
NEW YORK — By the time 10- yearold Sarah Murnaghan finally got a lung transplant last week, she’d been waiting for months, and her parents had sued to give her a better shot at surgery. Her cystic fibrosis was threatening her life, and her case spurred a debate on how to allocate donor organs. Lungs and other organs for transplant are scarce.
But what if there were another way? What if you could grow a custommade organ in a lab?
It sounds incredible. But just a threehour drive from the Philadelphia hospital where Sarah got her transplant, another little girl is benefiting from just that sort of technology. Two years ago, Angela Irizarry needed a crucial blood vessel. Researchers built her one in a laboratory, using cells from her own bone marrow. Today, the five- year- old from Pennsylvania sings, dances and dreams of becoming a firefighter — and a doctor.
Growing lungs and other organs for transplant is still in the future, but scientists are working toward that goal. In North Carolina, a 3- D printer builds prototype kidneys. In several labs, scientists study how to build on the internal scaffolding of hearts, lungs, livers and kidneys of people and pigs to make custom- made implants.
Here’s the dream scenario: A patient donates cells, either from a biopsy or maybe just a blood draw. A lab uses them, or cells made from them, to seed onto a scaffold that’s shaped like the organ he or she needs. Then, says Dr. Harald Ott of Massachusetts General Hospital, “we can regenerate an organ that will not be rejected ( and can be) grown on demand and transplanted surgically, similar to a donor organ.”
That won’t happen any time soon for solid organs like lungs or livers. But as Irizarry’s case shows, simpler body parts are already being put into patients as researchers explore the possibilities of the field.
A few weeks ago, an Illinois girl got an experimental windpipe that used a synthetic scaffold covered in stem cells from her own bone marrow. More than a dozen patients have had similar operations.
Dozens of people are thriving with experimental bladders made from their own cells, as are more than a dozen who have urethras made from their own bladder tissue. A Swedish girl who got a vein made with her marrow cells to bypass a liver vein blockage in 2011 is still doing well, her surgeon says.
In some cases the idea has even become standard practice. Surgeons can use a patient’s own cells, processed in a lab, to repair cartilage in the knee. Burn victims are treated with lab- grown skin.
In 2011, it was Irizarry’s turn to wade into the field of tissue engineering. She was born in 2007 with a heart with only one functional pumping chamber, a potentially lethal condition that leaves the body short of oxygen. Standard treatment involves a series of operations, the last of which implants a blood vessel near the heart to connect a vein to an artery, which effectively rearranges the organ’s plumbing.
Yale University surgeons told Irizarry’s parents they could try to create that conduit with bone marrow cells. More than 12 hours one day, doctors took bone marrow from Irizarry and extracted certain cells, seeded them onto a biodegradable tube, incubated them for two hours, and then implanted the graft into Irizarry to grow into a blood vessel.
It’s been almost two years and Irizarry is doing well . “She is able to have a normal play day,” said Irizarry’s mother, Claudia Irizarry.