Cryopreservation of stem cells is critical for preserving their viability for their use in therapy and transplantation. While routine in many transplantation procedures, crypreservation can still be a rather contentious issue. Indeed, the fact that no single cryopreservation method has been universally accepted points to the fragmented nature of the market (Berz et al., American Journal of Hematology 2007). Cryopreservation should be thought of as more than simply the process of freezing cells – it encompasses the selection and optimization of cryopreservation medium, the optimal freezing parameters, storage of the frozen cells, thawing and post-thaw viability analysis. As such, the right solution may very well require a custom approach. Traditionally, dimethylsulfoxide (DMSO) and glycerol have been the two most widely used cryoprotectants. In the case of DMSO, it works by preventing extra and intracellular formation of ice crystals, which is one of the main causes of damage to cells during freezing (Abbruzzese et al., Vox Sanguinis, 2013). While they are still commonplace in most cryopreservation protocols – particularly DMSO, which is the cryoprotectant of choice in the banking of stem cells – recent research has led to the development of new formulations with optimized DMSO concentration and the presence of additives which acts by reducing toxicity associated with traditional media. The presence of DMSO alone has been reported to cause toxicity in a number of recent transplantation procedures.
One such additive is dextran, which has been shown in recent studies to improve the yield and viability of post-thaw recovered cells (Wang et al., Cryobiology, 2010). Dextran works by stabilizing the cell membrane and aids the process of vitrification. When used with DMSO, it has shown to significantly improve cell viability.
Apart from dextran, sugars – mono, di and trisaccahrides – as well as polymers and albumin have also been used as stabilizers.
Since selecting the right cryopreservation medium is such a critical activity, why not work with a team that is well-versed in the intricacies of the process. Akron has years of experience in developing cryopreservation media and has competencies that can help at every step. Our market leading cryopreservation solution, CryoSolve, is a cGMP, serum-free and animal-free cryoprotectant composed of a mixture of dextran and DMSO with proven premium performance on preserving stem cell viability and recovery. Contact us with your custom needs — we are ready to help.