Cryopreservation of cartilage cell and tissue for biobanking.

Preservation of cell and tissue samples from endangered species is a part of biodiversity conservation strategy. Therefore, setting up proper cell and tissue cryopreservation methods is very important as these tissue samples and cells could be used to reintroduce the lost genes into the breeding pool by nuclear transfer. In this study, we investigated the effect of vitrification and slow freezing on cartilage cell and tissue viability for biobanking. Firstly, primary adult cartilage cells (ACCs) and fetal cartilage cells (FCC) were cryopreserved by vitrification and slow freezing. Cells were vitrified after a two-step equilibration in a solution composed of ethylene glycol (EG), Ficoll and sucrose. For slow freezing three different cooling rates (0.5, 1 and 2 °C/min) were tested in straws. Secondly, the tissues taken from articular cartilage were cryopreserved by vitrification and slow freezing (1° C/min). The results revealed no significant difference between the viability ratios, proliferative activity and GAG synthesis of cartilage cells which were cryopreserved by using vitrification or slow freezing methods. Despite the significant decrease in the viability ratio of freeze-thawed cartilage tissues, cryopreservation did not prevent the establishment of primary cell cultures from cartilage tissues. The results revealed that the vitrification method could be recommended to cryopreserve cartilage tissue and cells from bovine to be used as alternative cell donor sources in nuclear transfer studies for biobanking as a part of biodiversity conservation strategy. Moreover, cartilage cell suspensions were successfully cryopreserved in straws by using a controlled-rate freezing machine in the present study.