Fig. 3.

Sheep heart valve explant gross and histopathology. Heart valves were explanted at 6 months and photographed before further processing. (a) VS83 formulation stored at −80 °C in a mechanical storage freezer, (b) H&E-stained section of VS83 −80 °C explant after 6 months in vivo demonstrating cell-free leaflet with recipient cell-derived pannus overgrowth on the artery (bottom and leaflet top), (c) and (d) cryopreserved by freezing controls, (d) also demonstrating a hole in the base of leaflet, (e) and (f) VS83 formulation stored in vapor-phase nitrogen