Using Nutrient-rich Solutions and Adding Multiple Cytoprotective Agents As New Strategies to Develop Lung Preservation Solutions

Commonly, donor lungs are preserved with low-potassium dextran glucose solution at low temperature. We hypothesized that adding nutrients and/or cytoprotective agents to preservation solutions improves donor lung quality. Human lung epithelial cells and human pulmonary microvascular endothelial cells cultured at 37°C with serum containing medium were switched to designated testing solutions at 4°C with 50% O for different cold ischemic time, followed by switching back to serum containing culture medium at 37°C to simulate reperfusion. We found that bicarbonate buffer system should be avoided in preservation solution. When pH was maintained at physiological levels, cell culture media showed better cell survival than in low-potassium dextran glucose solution. Phosphate-buffered cell culture media were further improved by adding colloid dextran 40. When rat donor lungs were preserved at 4°C for 24 h, phosphate-buffered Roswell Park Memorial Institute-1640 medium [RPMI-1640(p)] plus dextran 40 or adding cytoprotective agents (alpha 1 antitrypsin, raffinose, and glutathione) to low-potassium dextran glucose solution prevented alveolar wall swelling, apoptosis, activation of endothelial cells, and cellular edema. Using nutrient-rich solution and/or adding multiple cytoprotective agents is a new direction for designing and developing organ preservation solutions. Cell culture model, as a screening tool, reduces the use of animals and provides potential underlying mechanisms.