One of the most common questions parents have about cord blood banking is, “How long can the stem cells be banked? Do stem cells have an ‘expiration date’ once stored?”

A recent study set out to answer that question by examining cord blood samples that have been processed and frozen for 21 to 23.5 years. Based on these current data and what is known about cryopreservation methods, no “expiration date” needs to be assigned to newborn stem cells stored continuously under the appropriate conditions. By freezing newborn stem cells, cord blood banking offers parents the opportunity of saving a valuable potential treatment option until needed by their child or other family members.

The researchers wanted to confirm findings from past studies that showed cord blood stored via cryopreservation—the process of being  cooled to very low sub-zero temperatures—retains the same composition as before storage without a significant loss of stem cell count, viability or proliferation.

To test this, the researchers infused the cord blood samples into mouse transplant models with compromised immune systems. They found that the cryopreserved cord blood successfully regenerated the blood and immune cells following transplantation at the same rate when compared to freshly isolated cord blood stem cells.

The results demonstrate that cord blood can be successfully stored frozen with highly efficient recovery, viability and function needed for successful cord blood transplantation.

Reference: Broxmeyer HE, et al. Hematopoietic stem/progenitor cells, generation of induced pluripotent stem cells, and isolation of endothelial progenitors from 21–23.5 year Cryopreserved cord blood. Blood. Mar 2011.