Lung Regeneration Based on Perfusion Decellularized Matrix Scaffolds
Harald C. Ott, MD, David Hoganson, MD, Ben Kipplinger, MD, Claudius Conrad, MD, Doris Taylor, MD, Joseph P. Vacanti, MD
Massachusetts General Hospital, Boston, MA
PURPOSE OF STUDY
More than 11 million Americans live with chronic lung disease; lung transplantation remains the ultimate treatment for end stage lung disease. Donor organ shortage increased waiting time over 500 days and waitlist mortality over 30%. In search for an alternative, we attempted to regenerate lungs that can be transplanted similar to a donor organ.
Lungs were isolated from heparinized adult SD rats (n=20) and decellularized using detergent perfusion. Resulting extracellular matrix (ECM) scaffolds were analyzed using histology, electron microscopy and mechanical testing. Scaffolds were mounted in a bioreactor and seeded with human umbilical cord endothelial cells (HUVEC, n=4), HUVECs and human alveolar basal epithelial cells (H-A549, n=4), and HUVECs and rat fetal lung cells (H-FLC, n=2). Culture was maintained up to seven days. Lung function was analyzed in an isolated lung apparatus using blood perfusion and ventilation. Normal lungs served as controls (n=4).
SUMMARY OF RESULTS
Perfusion decellularization of cadaveric rat lungs yielded acellular lung ECM scaffolds with intact airway and vascular architecture. Lung scaffolds were repopulated with endothelial and epithelial cells and maintained in a bioreactor. Gas exchange (PaO2/FiO2 ratio) was lower in H-A549 constructs (103.6mmHg), and equal in H-FLC constructs (455.1mmHg) compared to normal lung (465.8mmHg). Compliance was reduced in decellularized lungs (0.27ml/cmH2O/s), but equal in H-FLC constructs (0.67ml/cmH2O/s) and normal lung (0.69ml/cmH2O/s).
Perfusion decellularization of cadaveric rat lungs yields intact ECM scaffolds that can be seeded with epithelial and endothelial cells to form bioartificial lungs with ventilation, perfusion and gas exchange comparable to normal rat lungs.
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