Cryopreservation and Freeze-Drying of Heart Valves for Replacement Surgery

Malfunctioning heart valves can cause severe health problems, which, if left untreated, can lead to death. Heart valves can be replaced with biological heart valve constructs obtained from human or animal origin that closely resemble the properties of native heart valves. Tissue banking protocols are needed to ensure off-the-shelf availability in clinical settings. Heart valve tissue constructs may contain cells, or they can be decellularized to remove the immunogenic factors associated with cellular components. In order to preserve cells in the tissues, vitrification or freezing cryopreservation strategies can be used, whereas freeze-drying is particularly suitable to preserve decellularized heart valves. Here, we provide freezing, vitrification, and freeze-drying protocols to preserve heart valve conduits for replacement surgery. The protocols are described for porcine heart valves, but procedures can easily be adapted for material obtained from other species.