The Yale University/Duke University team reported their study and the results of the procedure in the June 24, 2010 issue of Science Express.
The paper is entitled 'Tissue-Engineered Lungs for in Vivo Implantation.'
The researchers involved in the study are Elizabeth A. Calle, MichaSam B. Raredon, Laura E. Niklason, Liping Zhao, Eun Jung Lee, Kseniya Gavrilov, Liqiong Gui, Tai Yi, Christopher Breuer, Zhen W. Zhuang, and Erica Herzog (all from various departments at Yale University, New Haven, Connecticut); and Thomas H. Petersen (from Duke University, Durham, North Carolina).
They stated in the abstract to their Science Express paper: 'Because adult lung tissue has limited regeneration capacity, lung transplantation is the primary therapy for severely damaged lungs. To explore whether lung tissue can be regenerated in vitro, we treated lungs from adult rats using a procedure that removes cellular components but leaves behind a scaffold of extracellular matrix that retains the hierarchical branching structures of airways and vasculature.'
And, 'We then used a bioreactor to culture pulmonary epithelium and vascular endothelium on the acellular lung matrix. The seeded epithelium displayed remarkable hierarchical organization within the matrix, and the seeded endothelial cells efficiently repopulated the vascular compartment.'
Page two continues with more about the procedure.
The researchers then placed the material in a glass jar where lung cells from rat fetuses were injected into the material.
Nutrients were also added to help the cells grow.
After a few days, the material had developed the structure found in a natural lung.
They added, 'In vitro, the mechanical characteristics of the engineered lungs were similar to those of native lung tissue, and when implanted into rats in vivo for short time intervals (45 to 120 min), the engineered lungs participated in gas exchange.' [Paper]
And, 'Although representing only an initial step toward the ultimate goal of generating fully functional lungs in vitro, these results suggest that repopulation of lung matrix is a viable strategy for lung regeneration.' [Paper]
Page three concludes with a video of the transplant.
The National Geographic News article 'First Working Replacement Lung Created in Lab' provides additional information about this exciting, first-of-its-kind ability to replace lung tissue into a living creature.
The article states, 'The achievement is a breakthrough in biomedical engineering that could lead to replacement lungs for humans in the near future, experts say.'
Hundreds of thousands of people in the United States die from lung-related diseases each year. Currently, only a transplant of a lung taken from a cadaver (dead human body) is possible. And, only 1 out of 5 of these people live for ten years or longer.
Such an ability, to engineer lung tissue in vitro, would greatly enhance the medical community's ability to reduce lung disease in humans.