Fetal bovine serum is not necessary for the cryopreservation of aortic valve tissues

The purpose of this study was to estimate the protective effects of fetal bovine serum on the cryopreservation of aortic valve tissues. Ten porcine aortic valves were divided into two groups according to the nutrient content of the medium used for sterilization and cryopreservation. Group A valves were preserved in Dulbecco's modified Eagle medium containing 10% fetal bovine serum, whereas group B valves were preserved in Dulbecco's modified Eagle medium alone. The fibroblast viability of the cryopreserved tissues was assessed autoradiographically with the use of tritiated proline at the following points: fresh control, after sterilization, and after storage for 1 week or 3 months. The proportion of viable fibroblasts decreased to a similar extent in both groups of tissues after 1 week of storage, 81.1% +/- 2.5% in group A and 80.4% +/- 3.3% in group B, and after 3 months of storage it decreased slightly to around 73% for both groups of tissues. No significant difference was observed between the two groups at any time. These result suggest that fibroblasts are adequately preserved even after 3 months of cryopreservation, and that the addition of fetal bovine serum to the medium does not further improve their viability. Thus, from a point of view of fibroblast viability, it is not necessary to use fetal bovine serum for the cryopreservation of aortic valve tissues.