J. NICHOLS, SCIENCE TRANSLATIONAL MEDICINE 2018
For the first time, a group of researchers have created lungs in a laboratory and successfully transplanted them to a pig.
These bioengineered lungs, described in Science Translational Medicine , developed healthy blood vessels that allowed pigs to live for several weeks after surgery without medical complications.
Unlike other cases of lungs transplanted into mice that only lasted a few hours, they seem more viable. If the new procedure can be adapted to humans, bioengineered lungs grown from a patient’s own cells could reduce the risk of organ rejection and shorten waiting times for organ transplants.
For the study, immunologist Joan Nichols and his colleagues at the University of Texas Medical Branch in Galveston built lungs for four pigs by first using a mixture of sugar and detergent to remove lung cells from donor pigs. Each designed lung grew for 30 days inside a bioreactor tank, filled with nutrient cocktails that helped the cells stick to the scaffolding and multiplied in the right places. Finally, the researchers replaced the left lung of each pig with the bioengineered version .
After the surgery, the Nichols team managed to get one pig to survive for ten hours, another for two weeks, a third for a month and the fourth for two months. None of the animals received immunosuppressive drugs, and none of the transplants were rejected. Within the body of a pig, the blood vessels of the bioengineered lung were connected to the natural circulatory system of the animal, supplying the organ with oxygen and nutrients to survive.
However, while the bioengineered lungs were linked to the circulatory systems of pigs, the organs were not connected to the lung arteries of the animals, which carry blood low in oxygen for the lungs to replenish oxygen from the inhaled air. That forced the pigs to rely on their natural right lung after the surgery. The next step is to connect the organ to the pulmonary artery “to ensure that genetically modified lungs can also perform this task.
