The evaluation of hematopoietic stem cells potential after 2 years of cryopreservation

The evaluation of the number، potential، and functional capacity of cord blood stem cells after long term storage is essential for their therapeutic uses in hematological malignancies and non-malignancies. Therefore، this study was aimed to assess the quality of cord blood units stored in Royan public cord blood bank، before and after cryopreservation. To check the quality of cryopreserverd cord blood units، the total number of cells، percentage of viable cells، colony-forming ability، the number of CD34+ cells before and after freezing were examined on 50 samples Our results determined that the mean value of the total nucleated cells in 50 cord blood samples was 7. 6 × 108 ± 1. 12 × 108. The number and viability of mononuclear cells as well as colony forming potential significantly decreased after cryopreservation; however، the count of viable CD34+ cells did not significant changes post thawing. There was no significant correlation between the numbers of nucleated cells and CD34+ cells. Increasing the storage time significantly reduces the number of nucleated cells and differentiation potential of hematopoietic stem cells rather than the number of CD34+ cells. Improved cryopreservation techniques are necessary to maintain the function of cord blood stem cells.