Viability and Potency of Hematopoietic Progenitor Cells after Prolonged Cryopreservation at –80°C

Preserved in vivo reconstitution ability of PBSCs cryopreserved for a decade at −80 °C

“…5,7,[18][19][20] However, few studies have addressed effects of LT storage of PBSC products. Costa et al 17 reported that viability of TNCs was around 80% and not changed with storage time up to 14 years. Engraftment was rapid in two patients who received autologous PBSCT stored for 8-9 years at − 80°C.…”

“…Clinical data also indicate that engraftment is not delayed in patients after autologous PBSCT using cryopreserved PBSCs for 3-9 years. [15][16][17] Regarding uncontrolled freezing and storage at − 80°C, several studies have shown that ST storage for months to several years does not decrease viability of CD34 + cells or colony-forming cells. 5,7,[18][19][20] However, few studies have addressed effects of LT storage of PBSC products.…”

“…This is probably because of the small numbers of samples since time-dependent increase in variability of cell viability was not reported. 5,14,17 Taken together, the quality of PBSC products appears to decline after 10 years of cryopreservation, irrespective of method of cryopreservation. Such an eventual loss of CD34 + cells should be taken into consideration before the use of LT cryopreserved PBSCs, as engraftment depends largely on CD34 + cell yields in both autologous and allogeneic PBSCT.…”

“…7,[17][18][19][20] The mechanical freezing method at − 80°C provides technical simplification and cost reduction, and therefore supports a hematopoietic stem cell transplant program in countries with limited resources in startup conditions as an alternative to liquid nitrogen storage, but requires a constant and reliable electrical power supply. However, our results need to be confirmed by clinical engraftment data or in future prospective studies to compare viability and recovery between bags cryopreserved at − 80°C or in liquid nitrogen from the same donors.…”

Essential requirements for setting up a stem cell processing laboratory

“…In a start-up situation, with limited resources, it is possible to maintain cellular therapy product viability using a ⩽ −70°C mechanical chest freezer instead of a programmable controlled rate freezer and LN 2 storage freezer. [8][9][10] Cellular therapy product stability can be maintained for several months at the warmer temperature by using a cryoprotectant consisting of 6% hydroxyethylstarch and 5% dimethyl sulfoxide (DMSO) and human albumin. 10 For longer-term storage (years) cryopreservation with a final concentration of 10% DMSO and storage in liquid or vapor phase nitrogen is still the preferred and most widely used methodology, as there has been some indication of a fall in GM-CFU (granulocyte macrophage colony-forming unit) colonies after 1 year of storage at − 80°C.…”