Abstract
BACKGROUND: The only definitive treatment for end-stage organ failure is orthotopic transplantation. Lung extracellular matrix (LECM) holds great potential as a scaffold for lung tissue engineering because it retains the complex architecture, biomechanics, and topologic specificity of the lung. Decellularization of human lungs rejected from transplantation could provide "ideal" biologic scaffolds for lung tissue engineering, but the availability of such lungs remains limited. The present study was designed to determine whether porcine lung could serve as a suitable substitute for human lung to study tissue engineering therapies. METHODS: Human and porcine lungs were procured, sliced into sheets, and decellularized by three different methods. Compositional, ultrastructural, and biomechanical changes to the LECM were characterized. The suitability of LECM for cellular repopulation was evaluated by assessing the viability, growth, and metabolic activity of human lung fibroblasts, human small airway epithelial cells, and human adipose-derived mesenchymal stem cells over a period of 7 days. RESULTS: Decellularization with 3-[(3-Cholamidopropyl)dimethylammonio]-1-propanesulfonate (CHAPS) showed the best maintenance of both human and porcine LECM, with similar retention of LECM proteins except for elastin. Human and porcine LECM supported the cultivation of pulmonary cells in a similar way, except that the human LECM was stiffer and resulted in higher metabolic activity of the cells than porcine LECM. CONCLUSIONS: Porcine lungs can be decellularized with CHAPS to produce LECM scaffolds with properties resembling those of human lungs, for pulmonary tissue engineering. We propose that porcine LECM can be an excellent screening platform for the envisioned human tissue engineering applications of decellularized lungs.