Yale University researchers have managed to engineer a mouse lung that successfully performed O2 / CO2 exchange when transferred into a live animal. By starting with a lung matrix depopulated of all its cells and then growing new lungs on top of that foundation, the researchers showed that functional lungs can be made almost from scratch.
The Yale team’s goal was to see if it was possible to successfully implant tissue-engineered lungs, cultured in vitro, that could serve the lung’s primary function of exchanging oxygen and carbon dioxide. They took adult rat lungs and first removed their existing cellular components, preserving the extracellular matrix and hierarchical branching structures of the airways and vascular system to use later as scaffolds for the growth of new lung cells.
They then cultured a combination of lung-specific cells on the extracellular matrix, using a novel bioreactor designed to mimic some aspects of the fetal lung environment. Under the fetal-like conditions of the bioreactor, the cells repopulated the decellularized matrix with functional lung cells. When implanted into rats for short intervals of time (45-120 minutes), the engineered lungs exchanged oxygen and carbon dioxide similarly to natural lungs.
The team found that the mechanical characteristics of the engineered lungs were similar to those of native tissues and, when implanted, were capable of participating in gas exchange.
Press release: Yale Scientists Implant Regenerated Lung Tissue in Rats…
Abstract in Science Express: Tissue-Engineered Lungs for in Vivo Implantation
