TWELVE THOUSAND MILES. That’s how far it is from 17-year-old Gabriel Omar Santoro’s home in Argentina to Beijing. It’s a journey he’s made twice in the past year — but neither trip was for pleasure.

Gabriel travelled to the Chinese capital from San Justo, a city on the suburban edge of Buenos Aires, for one specific reason. He has cerebral palsy, and in China he visited the Wu Stem Cells Medical Center, where he underwent a series of experimental procedures.

Journeys like this, and treatments like this, are not cheap. The Santoro family had to raise tens of thousands of dollars to pay for Gabriel’s visits to the Wu center. But they are not alone: Hundreds of children from Argentina, and many more from around the world, have made the same pilgrimage. Local media is well aware of these trips — indeed, slogans cheering along their fundraising campaigns are everywhere in newspapers and magazines: Go for it Santino! Everyone is rooting for Lola! Each campaign tells a different story, but each is ultimately about the same things: a child with a heart-wrenching condition, a family that craves a cure, a cutting-edge treatment that is only available in China.

And money. Lots and lots of money.

GABRIEL’S FAMILY IS MODEST: He lives with his mother, Alejandra, his father, Guillermo, and his 12-year-old sister, Milagros. Their home occupies two floors above the San Justo mechanics’ shop where Guillermo works. There is no doorbell. Everything looks unfinished because everything is unfinished: the walls, the floor, the rooftop — the house is incomplete, a work in progress.

The first time I visit and sit with Alejandra, the entire interview takes place with Gabriel in her arms. She doesn’t let go of him for a second, not even to answer the phone.

Gabriel’s palsy is profound. When he was born on March 8, 1996, he was immediately admitted to the hospital’s neonatal intensive care unit. The doctors diagnosed cerebral paralysis caused by cyanosis of the mucous membrane, apnea, and hypoxia. Put simply, Gabriel’s body had been starved of oxygen, and the parts of his brain that control his muscles had been damaged.

Alejandra prepares Gabriel’s meal.

Gabriel cannot sit up on his own, so Alejandra must hold him.

From the moment he was born, Gabriel needed help. He couldn’t eat because he didn’t have a sucking reflex. His entire body was stiff. He couldn’t move.

Today, the amount of medical equipment on which Gabriel depends is remarkable. In the living room there are oxygen tubes; beside his bed there is a kit to measure the amount of oxygen in his blood. On the table, there is a device that sucks mucous from his windpipe, a task made necessary by his recent tracheotomy. Without it, he could choke to death.

I watch as Gabriel takes a meal: a fresh peach smoothie, mixed with milk and a cocktail of drugs, administered through a tube connected to his stomach. Alejandra fills the tube with a giant syringe.

“The doctors told me that there would be other complications, more and more problems, that we had to be resigned to it,” she says while she refills the syringe. “They told me we had to understand Gabriel would have an expiry date, like a carton of milk.”

Alejandra has never believed these prognoses. Nor has she ever accepted the idea of an expiry date. She cannot explain whether it was faith or willpower; she just remembers what she said to Gabriel when he was born.

“I promised I would bring him up,” she says. “I didn’t know what would happen. Nothing was certain. He was a newborn baby.”

Over the years, Alejandra has tried everything she can to improve his living conditions, constantly investigating new treatments and following the latest medical progress and cutting-edge research. As the years went by, she collected every scrap of hope she could. That was how she came across stem cells.

She remembers how she began to get excited one night as she watched TV. As she tells me, Gabriel’s eyes are glued to the screen. It’s his favorite show, The Simpsons.

“One evening I was watching the Discovery Channel and I saw that they were making skin from stem cells. I nearly had a heart attack,” she recalls. “I said to myself, ‘Well, that’s the first step.’ Then I saw that Brazilian scientists had made a human heart from stem cells. ‘Wow,’ I thought. ‘I didn’t realize they were doing that.’”

That was when Alejandra decided that Gabriel needed stem cell treatment.

EVER SINCE THEIR EXISTENCE was first proposed by Russian scientist Alexander Maximow in 1908, stem cells have been viewed as a potential miracle treatment. They are blank slates and shape-shifters: cells that can become other types of cells. With the right chemical prompts, a stem cell can transform into the building block for hair, or heart muscle, or bone, or skin. This makes scientists extremely excited about their potential for medical use.

Many hope, for example, that a person with heart disease could receive an injection of stem cells that would replace the damaged heart tissue. Others believe the cells could replace a cancerous tumor in the liver, or even repair a damaged spinal cord, or even build new organs from scratch. The more extreme possibilities regularly grab the media’s attention, for instance when Dutch researchers turned muscle stem cells from a cow into a “stem cell burger” in August 2013 (verdict: edible, but lacking in fat and flavour).

The potential of stem cells, though, is hampered by the fact that they are hard to work with. Some have inherent limitations: By the time we reach adulthood, our bodies contain relatively few stem cells, and, if harvested, they typically specialize into cells used by the organ from which they came. Those from bone marrow, for example, typically differentiate into blood cells and platelets. Stem cells from the brain, meanwhile, turn into the neurons and astrocytes that make up the brain and spinal cord.

Others are more flexible, but controversial. Those found in early human embryos are capable of turning into any type of cell, but because they require destroying the embryo, they have become very contentious — particularly in the United States, where legal restrictions on use of the cells has slowed progress.

Despite these problems, clinical trials of stem cells therapies are taking place around the world. There are three for cerebral palsy in the United States alone. In one study, based at Duke University, researchers are using stem cells extracted from the patients’ umbilical cords. The cells are injected back into the child’s blood, in the hope of reducing inflammation in the brain, or encouraging the brain to repair some of its damaged neurons. But because the treatments haven’t been proven safe or effective, they aren’t yet available commercially.

Clinics that try to skate around these restrictions can be shut down: In recent years the Federal Drug Administration has shuttered one clinic in Colorado and one in Texas, where governor Rick Perry — Bush’s ultra-conservative successor — received an experimental stem-cell injection for back pain.

Many patients and their families, understandably desperate for treatment, see Western regulations as cutting them off from hope. The rules are intended to ensure that patients only receive genuine, helpful treatment. But that means that unproven cutting-edge treatments are only available to those who can travel to countries such as India and China, where regulations are more lax, and stem cell therapies are offered at many hospitals and clinics. And so, like Alejandra and Gabriel, they save up their money and go abroad.

AFTER WATCHING THE STEM CELL documentary on TV, Alejandra started her quest by turning to the Internet.

There are a few clinical trials of new stem cell therapies taking place in China, but commercial treatments are restricted in Argentina — as they are in most of the world — so going international was her only option. It didn’t take long before she came across the Wu Clinic. The website featured the image of a complicated-looking operating theater, with the face of Dr. Like Wu, the founder, half-smiling out at her. Her eyes lingered over a sequence of photos of children who reminded her of Gabriel. She clicked.

The Wu Stem Cells Medical Center’s website

A week later a confirmation arrived in her inbox: A message that said, yes, there was a possibility that the Wu Clinic could treat Gabriel. She was asked to send all of his medical records. Things moved fast: within weeks, they had a quote and a potential date.

The Wu clinic offered Gabriel a program of four stem cell implants, at a rate of one per week. The service included lodging for him and two companions, laundry service, hospital services, medical equipment, and the medication that would be required while he was at the clinic.

“When they said to me that it would be $30,000 per treatment, I nearly dropped dead,” says Alejandra. “I told them that I didn’t have this sort of money. I went white from the start, because I knew I would have to rely on people’s sympathy. I don’t think they understood what this meant.”