Below is the evaluation of Bone Marrow-Derived MSCs after Cryopreservation and Hypothermic Storage; a recent paper in Tissue Engineering by Dr Irene Ginis and colleagues at Teva Pharmaceuticals.
In probably the first study to examine the efficacy of long term cryopreservation of human bone marrow-derived Mesenchymal Stem Cells (MSCs) in an animal product-free medium, the efficacy of cryopreservation of MSCs was evaluated by Dr Irene Ginis and colleagues at the Cell Therapy Laboratory in Teva Pharmaceuticals. There is a definite need from users of MSCs for a clinically acceptable "off-the-shelf" cell therapy product.
A rate controlled freezing program was optimised and carried out in one of our programmable cell freezers. About 95% of frozen cells were recovered as live cells after freezing in CryoStor xeno-free media, with 5% and 10% DMSO followed by storage in liquid nitrogen for a month. Cell recovery after five months storage was also good (around 80%) and proliferation of MSCs measured during 2 weeks post-plating was not compromised and seemed even enhanced. In addition to good recovery the percentage of apoptosis in recovered MSCs after storage in liquid nitrogen was also low. Cryopreservation did not alter expression of MSC markers and their ability to differentiate into bone progenitors.
Overall the results demonstrated that human MSCs could be successfully cryopreserved for banking and for preservation of patient's own cells for repetitive transplantations.
Regeneration of non-union bone fractures is a long process taking months and in cases of substantial bone loss even years. It is likely that repetitive MSC transplantation will be necessary to accomplish full healing. Therefore successful clinical grade cryopreservation of MSCs for bone repair is the most urgent need. In the study previously cryopreserved MSCs demonstrated the same degree of osteogenic differentiation as their unfrozen counterparts.
The authors evaluated clinical grade media for cryopreservation of human MSCs using a 560 Planer programmable cell freezer and they optimised freezing and thawing programs. Quantitative tests of cell viability and apoptosis were adapted for MSCs still remaining in post thaw suspension. Enhanced proliferation rates of post-cryopreserved MSC were observed - an important point to note for the scientific community.
The authors believe that this study will contribute to acceleration of MSC application for treatment of non-union bone fractures and other types of tissue injury. Successful cryopreservation and storage of MSCs should promote the creation of MSC banks. Dr Ginis and colleagues hope that a standardised protocol for MSC cryopreservation would also resolve variability of the data between different laboratories and enhance collaborations within the research community.
For full text see Tissue Engineering: http://online.liebertpub.com/doi/abs/10.1089/ten.TEC.2011.0395