Application of Cryopreservation Technique in the Preservation of Rat Limbs

The aim of this study was to observe the physiologic and pathologic changes of severed fingers (limbs) under different storage conditions through animal experiments, and to screen out the best preservation conditions.

Sixty healthy adult male Sprague-Dawley rats were selected and evenly divided into 4 preservation groups, including conventional low-temperature dry (CLTD), the University of Wisconsin (UW) solution, cryopreservation, and cryopreservation + UW solution preservation group. After harvesting the limbs, were preservated for 72 hours and 7 days, respectively. Then the limbs were thawed and replanted in situ. Sciatic nerves were collected for hematoxylin & eosin (H&E) staining and observed the changes in tissue morphology.

Replantation was successful in 11 of 15 rats (73%) in the cryopreservation + UW group, and the walking function of the 9 (82%) rats in cryopreservation + UW group were significantly better than that of the cryopreservation preservation group. Additionally, the H&E staining results shown that the CLTD group nerve bundles were morphologically damaged, and there were more acellular structures and tissue fragments; the UW group nerve bundles were less injured and the perineurium was more complete and more orderly. The nerve bundles in the cryopreservation group and the cryopreservation + UW group are tightly arranged, and the tissue morphology is regular. Compared with the cryopreservation + UW group, the completeness of the cryopreservation group was not sufficient.

The cryopreservation technology combined with the UW solution is a new and effective method for preservation of severed limbs.