The New York state Μedical Department in its guidelines announced that stem cells stored in very low temperatures (like liquid nitrogen -1960 C) can survive indefinitely and maintain all their biological functions. ‘There is no evidence at this moment that the cells that are cryopreserved at -196°C loose either the determined in-vitro viability or their biological activity”. So at this moment, no expire date can be determined for umbilical cord blood stem cells that is stored in liquid nitrogen conditions. A study that was published from Broxmeyer et al 2003, showed that after post-thaw, umbilical cord blood stems cells that they had preserved for 15 years maintained all their biological activities.
In research laboratories there are viable cells in liquid nitrogen conditions since the ’60.
The science that concerns the cryogenic storage of the cells, states that the cells remain viable for an infinite time. The test for viability of stem cells in Biohellenika’s labs after post thaw, showed high percentage of viable cells. Until now, two children with cerebral palsy had been treated successfully with umbilical cord blood stem cells after post-thaw that had been cryopreserved for at least 2 years.
1. Broxmeyer HE et al, 2003. High efficiency recovery of functional hematopoietic progenitor and stem cells from human cord blood cryopreserved for 15 years. PNAS USA, 100(2): 645-50.
2. Koliakos G, Alamdari D, Tsagias N, Kouzi-Koliakos K, Michaloudi E, Karagiannis V. A novel high-yield volume-reduction method for the cryopreservation of UC blood units. Cytotherapy. 2007,9(7):654-9