(AP) - Sarah Murnaghan had to wage a high-stakes legal fight to get a new pair of lungs.
By the time the 10-year-old cystic fibrosis patient finally received a double-lung transplant last week, she'd been waiting for months.
Her parents had sued to get her on the adult transplant list and a better shot at getting the surgery.
Sarah's case spurred a national debate about how organs are allocated in the face of chronic shortages in the United States.
But what if there was another way: If a person needs an organ, can you just grow one in a lab?
Scientists are trying to help ease the shortage and have tapped into the body's own ability to regenerate itself.
"We're harvesting that technology to create more complex tissues," said Dr. Anthony Atala, director of the Wake Forest Institute for Regenerative Medicine at Wake Forest University.
Researchers there want to see if they can make pig livers suitable for people.
They're starting with piglet livers and washing them in a process called decellularization, which strips the pig's cells off its liver but leaves the underlying structure behind.
The hope is to seed that structure with human liver cells to see if those cells will grow and multiply into a fully functioning human liver.
"Pigs, the size is closer to a human liver. So if we're able to decellularize and put human cells back in there, it could help with the shortage of organs," said Abritee Dhal, a PhD candidate at Wake Forest University in Winston-Salem, North Carolina.
The lab is also trying to make kidneys with the use of a 3D printer. The "ink" that comes out of the printer is made of various cells and a gel-like material to help support them.
The ability to grow and implant complex organs like hearts, lungs, livers and kidneys in humans is still a long way off.
Some researchers think it's as little at 10 years but possibly more like 20 years away for some organs.
There has been some success so far in creating simpler, hollow body parts.
Right now, there are people living with custom-made, lab-grown blood vessels, windpipes and bladders in the U.S.
To engineer those, scientists can take cells from a patient's own bone marrow or a biopsy of the needed body part and grow those cells on a biodegradable, synthetic scaffold.
The scaffold is also produced by a 3D printer in the exact size and shape needed. The "ink" is the scaffold material itself.
"Once these scaffolds are in the body with the cells, the scaffolds go away, and the cells lay down their own scaffold," said Atala.
That process helped five-year-old Angela Irizarry.
She was born in 2007 with a heart defect that prevented her heart from pumping blood through her body.
It's a potentially lethal condition that leaves the body short of oxygen.
"She couldn't run or play or cry without getting tired and purple," said Claudia Irizarry, Angela's mother.
Angela had a series of surgeries, the last of which was to implant a lab-grown blood vessel made from cells in her bone marrow.
That was two years ago, and now her mother says she is a normal little girl who just graduated preschool and is looking forward to kindergarten.
"She is able to be, to have a normal play day," said Claudia Irizarry from the family's home in Lewisburg, Pennsylvania.
Success stories like Angela's are spurring the research forward.
Scientists say the trick is to find the right cells to use for what's needed, get them on the right support structure and then get them growing.
"Our preference is to use a patient's own cells, and the patient's own organ specific cells because those cells already know what to do," said Atala. "A windpipe cell already knows that it's a windpipe cell, and it's going to create a windpipe cell for that patient that will not be rejected or kicked out."
The end goal: To create custom-made organs in the lab, on demand, that the body will accept.
Scientists say that could help end the waiting game for donor organs, which some patients never receive.