The Application of a New-type Bioreactor in the ex vivo Expansion of Hematopoietic Stem/Progenitor Cells

Based on the requirement of culture conditions for hematopoietic stem and progenitor cells (HSPCs) ex vivo expansion, we developed a new-type bioreactor by combining superiorities of static and stirred culture models. Stem cell factor(SCF), thrombopoietin(TPO), FLT-3 ligand(Flt-3) were used as the cytokines cocktails. The effects of the static and cyclic culture on the expansion characteristics of CD34+ selected cells were compared in the new-type bioreactor. After 7 d cultures, the expansion of total cells in the static culture was 13.86 ± 4.26 fold, higher than that in the cyclic culture (7.23 ± 2.67 fold). This indicated the superiority of static culture in total cells expansion. The analysis of the fold expansion and the proportion of CD34+ cells showed that there was no marked difference between the static culture and the cyclic culture. However, the fold expansion and the proportion of CD34+CD38− cells were higher in the cyclic culture than those in the static culture (3.90±0.85 versus 1.82±0.58, 37.47±14.06% versus 9.45±4.85%), which reflected more primary CD34+CD38− cells were obtained in the cyclic culture. The above results demonstrated that both the static culture and the cyclic culture could be used in ex vivo expansion of CD34+ cells with the new-type bioreactor. In static culture hematopoietic stem cells differentiated into progenitor cells, whilst the cyclic culture favored the expansion of primary HSPCs.