'You see those rats running on the treadmill and you think of a kid who could be able to run with his peers, play soccer or hockey,' says Dr. Bernard Thébaud. (University of Alberta)

Stem cells have helped to heal the lungs of newborn rats, a finding that could someday help premature babies, researchers in Alberta say.

Many babies who are born early have underdeveloped lungs and need to be hooked up to a ventilator, which can cause permanent lung damage. About half of babies born before 28 weeks develop chronic lung disease that harms their lung capacity as they get older.

Now researchers have found that by injecting stem cells from bone marrow into the airways of rats, the cells pumped out a healing liquid that seemed to repair the lungs, Dr. Bernard Thébaud and his colleagues report in the Dec. 1 issue of the American Journal of Respiratory and Critical Care Medicine.

The lungs of baby rats are similar to the lungs of a 24-week premature human baby.

"I think that these findings have real clinical applications," said Thébaud, who divides his time between caring for newborns struggling to breathe at the Stollery Children's Hospital in Edmonton and peering into a microscope to examine the effect of stem cells on lungs at his university lab.

"We have to do our homework first, make sure it's safe and make sure it is efficient in the short and in the long term. So we're doing this work right now."

Treated rats ran twice as far

Thébaud worked on the research for five years with doctors from Tours, France, as well as in Chicago and Montreal.

They found rats that received the stem cells were able to run twice as far and were more likely to survive than the rats that did not receive the injection.

Thébaud is optimistic that clinical trials could start on human babies in the next three to five years.

Before then, more research is needed to look at potential side effects of the stem cells, such as tumour growth. The concern arises since stem cells have the potential to become any type of cells, including cancerous ones.

The team is also studying whether the stem cells need to be injected or if the liquid produced by the cells could be harnessed instead.

As he looked at rat tissue under the microscope and watched rodents scurry on treadmills, Thébaud said he kept thinking of the babies he was trying to help.

"You see those rats running on the treadmill and you think of a kid who could be able to run with his peers, play soccer or hockey," he said. "That's what matters."

A pediatrics professor at the University of California, San Francisco, has already offered her congratulations to the research team.

"This research offers real hope for a new treatment for babies with chronic lung disease," Dr. Roberta Ballard, said in a media release.

The research was partly funded by the Alberta Heritage Foundation for Medical Research.

With files from The Canadian Press