Fig. 4.

Morphological appearance of rabbit chondrocyte sheets after long-term vitrification preservation. The morphological appearance of rabbit chondrocyte sheets that were stored for long periods in the vitrification storage box was observed. a: Non-vitrified control cell sheet. b: The cell sheet vitrified with the envelope method and immediately rewarmed (vitrified control). c, d: Intact morphology of the cell sheets vitrified in the vitrification storage box and stored in the LN container for one month (c) and six months (d).