Aims
Current
Conclusions
High pre-freeze senescence appears to correlate with poor post-thaw function in MSC samples, but additional studies are necessary to obtain a sample sizes large enough to quantify results.
Methods
Human bone marrow aspirate was used. MSCs were isolated and cells were assessed for total count, viability, apoptosis and senescence over 6 passages (8-10 doublings/passage) in ex vivo culture. One half of cells harvested at each passage were re-plated for continued culture and the other half were frozen at 1°C/min in a controlled-rate freezer. Frozen samples were stored in liquid nitrogen, thawed and reassessed for total cell count, viability and senescence immediately and 48 h after thaw.
Results
Viability did not differ significantly between samples before freeze or after thaw. Senescence increased over time in pre-freeze culture and was significantly higher in one sample that had growth arrest both before freeze and after thaw. Freezing resulted in similar initial post-thaw recovery in all samples, but 48-h post-thaw growth arrest was observed in the sample with high senescence only. Conclusions: High pre-freeze senescence appears to correlate with poor post-thaw function in MSC samples, but additional studies are necessary to obtain a sample sizes large enough to quantify results.