Comparative study on effects of cryopreservation of umbilical cord hematopoietic stem/progenitor cells

Objective To investigate the effects of different cryopreservation conditions for umbilical cord blood cells and hematopoietic stem/progenitor cells isolated by 1.064 g/L Ficoll(1064 hematopoietic stem/progenitor cells). Methods Twenty-one cases of cord blood and 12 cases of 1064 hematopoietic stem/progenitor cells were preserved in 4℃.Sixteen cases of 1064 hematopoietic stem/progenitor cells were kept in -80℃ and -196℃ respectively. Activities of these hematopoietic cells were examined at different time intervals.Monounclear cells(MNC) were detected by blood cell analyzer. CD34 + cells were analyzed by Flow Cytometry(FCM). CFU-GM and CFU -E were cultured in vitro. The rate of survival cells was determined by Trypan blue staining.Results MNC, rate of survival cells,CFU -GM and CFU-E of umbilical cord blood had no significant changes on the first and second day. CFU-GM and CFU-E decreased obviously from the third day to the fifth day. CFU-GM and CFU-E for 1064 hematopoietic stem/progenitor cells preserved in 4℃ began to decrease on the third day, reduced strikingly on the fifth day. CFU-GM,CFU-E and CD34 + cells of 1064 hematopoietic stem/progenitor cells preserved in -80℃ or -196℃ had no changes during six months. The 3 markers decreased after one year. However,the above indicators and cell cycline of these cells kept in -80℃ for six months had no striking changes and more than 98 of percent the cells were in G 0-G 1 phase, as well as the cells kept in -196℃ for one year. Conclusions Optimal time of cryopreservation in 4℃ for cord blood cells is within three days. The effects of cryopreservation for umbilical cord hematopoietic stem/progenitor cells are consistent in preserving in -80℃ and -196℃ during six months. The method for long-preservation in -196℃ is reliable, however, the method of preservation of umbilical cord hematopoietic stem/progenitor cells in -80℃ is practical, unexpensive and effective.