Cryopreservation is required to preserve the native properties of tissue for prolonged periods of time. In this
study, we evaluate the impact that 4 different cryopreservation protocols have on porcine urethral tissue, to
identify a protocol that best preserves the native properties of the tissue. The cryopreservation protocols include
storage in cryoprotective agents at − 20 ◦C and − 80 ◦C with a slow, gradual, and fast reduction in temperature.
To evaluate the effects of cryopreservation, the tissue is mechanically characterised in uniaxial tension and the
mechanical properties, failure mechanics, and tissue dimensions are compared fresh and following
cryopreservation.
The mechanical response of the tissue is altered following cryopreservation, yet the elastic modulus from the
high stress, linear region of the Cauchy stress – stretch curves is unaffected by the freezing process. To further
investigate the change in mechanical response following cryopreservation, the stretch at different tensile stress
values was evaluated, which revealed that storage at − 20 ◦C is the only protocol that does not significantly alter
the mechanical properties of the tissue compared to the fresh samples. Conversely, the ultimate tensile strength
and the stretch at failure were relatively unaffected by the freezing process, regardless of the cryopreservation
protocol. However, there were alterations to the tissue dimensions following cryopreservation that were
significantly different from the fresh samples for the tissue stored at − 80 ◦C.
Therefore, any study intent on preserving the mechanical, failure, and geometric properties of urethral tissue
during cryopreservation should do so by freezing samples at − 20 ◦C, as storage at − 80 ◦C is shown here to
significantly alter the tissue properties