Researchers have transplanted bioengineered lungs into pigs successfully for the first time, according to a study published this week (August 1) in Science Translational Medicine. 

The team harvested lungs from dead pigs to construct a scaffold for the bioengineered lung to hold fast to. They used a solution of soap and sugar to wear away all the cells of the lungs, leaving behind only collagen, a protein that forms the support structure of the organ. Next, they removed one lung from every recipient pig, and used cells from those lungs, together with the collagen scaffold, growth factors, and media, to grow a new lung in a bioreactor. After a month, the lungs were transplanted into the recipient pigs. 

As the cells came from the same animal that then received a bioengineered lung, there was no organ rejection. The researchers euthanized the recipient animals and tested their lungs 10 hours, two weeks, and one and two months following transplantation. 

The team found that before the pigs were euthanized, the transplanted lungs developed without any outside help, building blood vessels they needed for survival. “The bioengineered lung facilitates the development of a blood supply and provides for the establishment of natural lung microbial flora,” John Hunt, who studies tissue engineering at Nottingham Trent University in the UK and was not involved in this research, tells BBC News. However, even the two-month-old transplanted lung, while not showing any fluid collection that would indicate an underdeveloped organ, had not developed enough to independently supply the animal with oxygen.

The researchers hope that bioengineered lung transplants will be feasible in humans within a decade. But first, coauthor Joan Nichols of the University of Texas Medical Branch at Galveston tells Popular Science, the team will “need to prove that the animals can survive on the oxygen provided by the engineered lung alone.”