Lab grown lungs can be created from a recipient's own cells, evading the need to use immunosuppressant therapies, but they often fail in animal experiments because they do not develop proper blood vessel networks.
Scientists from the University of Texas Medical Center at Galveston have developed a new method to create perfectly matched bioengineered pig lungs that can grow their own circulatory systems.
To do this, they used lung cells from pigs that were not part of the study to provide the scaffold of a new lung. To prevent rejection, the scaffold cells must be washed in a combination of sugar and detergent so that all traces of the animal it came from are removed and only proteins remain (a process termed decellularisation). The scaffold is then bathed in a 'cocktail' of the recipient pig's cells and nutrients and grown for 30 days.
The pigs were monitored for two months following the transplant procedures. The lab-grown organs functioned remarkably well and continued to improve over time. As quickly as two weeks after the transplants, the scientists saw that the proverbial vessel seeds they had planted had grown into strong networks to transport blood through the lungs.
'We saw no signs of pulmonary edema, which is usually a sign of the vasculature not being mature enough' said Dr Cortiella and his co-author Dr Joan Nichols.
'The bioengineered lungs continued to develop post-transplant without any infusions of growth factors, the body provided all of the building blocks that the new lungs needed.'
The method requires rigorous testing to prove that the lungs are truly viable, however, these early results are very promising. The team hope that the technique could be applied in compassionate studies in humans within 5-10 years and may one day offer a life-saving solution for countless patients.