Normothermic Ex Vivo Heart Perfusion with Mesenchymal Stem Cell-Derived Conditioned Medium Improves Myocardial Tissue Protection in Rat Donation after Circulatory Death Hearts

Figure 1

Simplified schematic image of the collection of CM from BMSCs and normothermic ex vivo heart perfusion combined with CM treatment. After rats were euthanized, the bone marrow was isolated by using phosphate-buffered saline (PBS) to flush the femurs and tibias. The cells were incubated on cell culture flasks at 37°C with 5% CO₂. After BMSCs reached more than 80% confluency at passage 3, the medium was aspirated, and PBS was used to rinse the cells 3 times. Then, BMSCs were added with α-MEM on culture flasks in an incubator for 24 h. After primary CM was collected, concentrated CM was obtained by centrifuging primary CM with ultrafiltration units (5000 g for 2 h at 4°C). BMSCs: bone marrow mesenchymal stem cells; CM: condition medium; DCD: donation after circulatory death; EVHP: ex vivo heart perfusion.