Reconstructing the Lung

Engineering functional lung tissue on the structural scaffold of the native organ in rodents points to a possible strategy for lung regeneration. From an engineering and materials science perspective, the lung is a paradigm of design efficiency. A gas transfer surface area of approximately 70 m 2 is packed into an elastic, dynamic structure to accomplish efficient oxygen and carbon dioxide transfer. There has been modest success in organizing cells into small-scale structures that mimic pulmonary tissue, but the question of how to scale up and effectively connect such structures has loomed large. Two studies by Petersen et al. on page 538 of this issue ( 1 ) and by Ott et al. ( 2 ) describe an alternative approach by which the structural efficiencies of native lung tissue can be captured while potentially avoiding the immunogenicity barriers associated with nonautologous tissue transplantation.