Cryopreservation in vapor-phase liquid nitrogen is a long-term storage method that enables most of the cells to remain viable. These very low temperatures also help to reduce histocompatibility receptor levels and avoid the risk of implanted tissues being rejected by the recipient.

After decontamination in antibiotics, the tissues are immersed in a cryopreserving solution that ensures a slow formation of the ice crystals and prevents hyperosmolar shock.

The tissues are stored in strong bags. They reach the established low temperatures in a controlled cryofreezing procedure (the temperature dropping by 1°C a minute) to safeguard the tissues’ mechanical resistance.

The tissues are stored in a tank in vapor-phase nitrogen under thermostat control and may be used for transplantation for up to five years after freezing. The methods adopted comply with Italian national guidelines and have been accredited in accordance with the standards of the Italian National Transplant Center.