Posted on over 3 years ago by Larry O'Leary
Scientists at the University of Michigan figured out long ago how to coax stem cells to grow into miniature lungs. But when they attempted to transplant the organs into mice, they failed, because the miniature lungs lacked the maturity and structure needed to be able to facilitate breathing.
So biologists at the university teamed up with biomedical engineers to develop a solution to the problem. Employing a biodegradable scaffold that had previously been used to transplant tissue into animals, they made a stiff structure that they could attach to the minilungs.
The scaffolding provided an environment in which the lungs could mature and develop many of the structures and cells seen in human adult lungs, including an epithelial layer. When they transplanted them into mice, the lungs survived and continued maturing.
"In just eight weeks, the resulting transplanted tissue had impressive tube-shaped airway structures similar to the adult lung airways,” said Briana Dye, a graduate student in the university’s department of cell and developmental biology and the lead author of the study, which was published in the journal eLife. The only tissue that didn’t grow was the alveolar cells, which are important players in gas exchange. The authors wrote in the paper that further studies will be required to determine how best to propagate alveolar cells.
The ability to grow lungs in a lab dish could be a boon to the study of lung diseases, which account for one in five deaths globally. Miniature lungs might someday be used to screen drug candidates, for example. And perfecting the process of growing lung tissue from stem cells could ultimately produce tissue that can be transplanted into patients with asthma and other diseases that damage the organ.
The prevalence of lung disorders has sparked a wave of research around the world aimed at improving the diagnosis and treatment of respiratory diseases. In September, for example, scientists at the University of Leuven in Belgium presented a study in which they used machine learning to improve tests for measuring lung function and diagnosing disease.
In the U.S., federal funding for research aimed at treating lung diseases has increased steadily over the last few years, from $1.29 million in fiscal 2012 to $1.68 million last year, according to the National Institutes of Health. That could provide valuable support to the Michigan scientists, who were partially funded by the NIH. They point out in their study that unlike other models of human lung tissues, implantable minilungs have the potential to interact with their host’s immune system, making it possible to model inflammation and other responses to disease and injury.
“Future directions will be aimed at exploiting this new in vivo model of the human airway to better understand disease and to improve human health,” they wrote.
See original study: http://bit.ly/2fe7Aq6