Theranostic methodology for ex vivo donor lung rehabilitation

Background: About 80% of donor lungs are not utilized for transplantation. Cross-circulation of ex vivo lungs with a support swine enables the rehabilitation of donor lungs that are initially deemed unsuitable for transplantation. Robust therapeutic and diagnostic modalities are needed for ex vivo lung rehabilitation; however, no standardized “theranostic” methodology has been reported. Methods: Ex vivo lungs (n = 23; 17 injured and 6 controls) with multi-focal contusion (n = 6, human), gastric aspiration injury (n = 8, swine), ischemia-reperfusion injury (n = 3, swine), or no injury (n = 6, swine) were used to develop a therapeutic and diagnostic (theranostic) methodology for ex vivo lung rehabilitation during cross-circulation. Airway (bronchoscopic, nebulized), intravascular, and transpleural access enabled sample collection and therapeutic delivery. Diagnostic modalities included non-invasive imaging, functional testing, and molecular assays. Therapeutic modalities included bronchoalveolar lavage, surfactant replacement, recruitment maneuvers, and cell/organoid delivery. Real-time tracking of delivered cells was performed via fluorescence and bioluminescence imaging. Findings: Diagnostic assessments revealed tissue-, cell-, and molecular-level insights at global and regional scales of ex vivo lungs during cross-circulation, which informed therapeutic management and interventions to recover donor lungs. Mesenchymal stromal cells and lung organoids were delivered bronchoscopically and transpleurally, tracked non-invasively during cross-circulation, and observed to localize within the parenchyma. Conclusions: Application of a theranostic methodology during cross-circulation enabled real-time ex vivo lung assessment and rehabilitation across a variety of lung injuries to help increase clinical utilization of donor lungs in the future. Funding: NIH (P41 EB027062, R01HL120046, U01HL134760), CFF (VUNJAK23XX0).